/* * SSLv3/TLSv1 shared functions * * Copyright (C) 2006-2014, Brainspark B.V. * * This file is part of PolarSSL (http://www.polarssl.org) * Lead Maintainer: Paul Bakker * * All rights reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ /* * The SSL 3.0 specification was drafted by Netscape in 1996, * and became an IETF standard in 1999. * * http://wp.netscape.com/eng/ssl3/ * http://www.ietf.org/rfc/rfc2246.txt * http://www.ietf.org/rfc/rfc4346.txt */ #if !defined(POLARSSL_CONFIG_FILE) #include "polarssl/config.h" #else #include POLARSSL_CONFIG_FILE #endif #if defined(POLARSSL_SSL_TLS_C) #include "polarssl/debug.h" #include "polarssl/ssl.h" #if defined(POLARSSL_X509_CRT_PARSE_C) && \ defined(POLARSSL_X509_CHECK_EXTENDED_KEY_USAGE) #include "polarssl/oid.h" #endif #if defined(POLARSSL_PLATFORM_C) #include "polarssl/platform.h" #else #define polarssl_malloc malloc #define polarssl_free free #endif #include #if defined(_MSC_VER) && !defined strcasecmp && !defined(EFIX64) && \ !defined(EFI32) #define strcasecmp _stricmp #endif /* Implementation that should never be optimized out by the compiler */ static void polarssl_zeroize( void *v, size_t n ) { volatile unsigned char *p = v; while( n-- ) *p++ = 0; } /* Length of the "epoch" field in the record header */ static inline size_t ssl_ep_len( const ssl_context *ssl ) { #if defined(POLARSSL_SSL_PROTO_DTLS) if( ssl->transport == SSL_TRANSPORT_DATAGRAM ) return( 2 ); #else ((void) ssl); #endif return( 0 ); } #if defined(POLARSSL_SSL_MAX_FRAGMENT_LENGTH) /* * Convert max_fragment_length codes to length. * RFC 6066 says: * enum{ * 2^9(1), 2^10(2), 2^11(3), 2^12(4), (255) * } MaxFragmentLength; * and we add 0 -> extension unused */ static unsigned int mfl_code_to_length[SSL_MAX_FRAG_LEN_INVALID] = { SSL_MAX_CONTENT_LEN, /* SSL_MAX_FRAG_LEN_NONE */ 512, /* SSL_MAX_FRAG_LEN_512 */ 1024, /* SSL_MAX_FRAG_LEN_1024 */ 2048, /* SSL_MAX_FRAG_LEN_2048 */ 4096, /* SSL_MAX_FRAG_LEN_4096 */ }; #endif /* POLARSSL_SSL_MAX_FRAGMENT_LENGTH */ static int ssl_session_copy( ssl_session *dst, const ssl_session *src ) { ssl_session_free( dst ); memcpy( dst, src, sizeof( ssl_session ) ); #if defined(POLARSSL_X509_CRT_PARSE_C) if( src->peer_cert != NULL ) { int ret; dst->peer_cert = (x509_crt *) polarssl_malloc( sizeof(x509_crt) ); if( dst->peer_cert == NULL ) return( POLARSSL_ERR_SSL_MALLOC_FAILED ); x509_crt_init( dst->peer_cert ); if( ( ret = x509_crt_parse_der( dst->peer_cert, src->peer_cert->raw.p, src->peer_cert->raw.len ) ) != 0 ) { polarssl_free( dst->peer_cert ); dst->peer_cert = NULL; return( ret ); } } #endif /* POLARSSL_X509_CRT_PARSE_C */ #if defined(POLARSSL_SSL_SESSION_TICKETS) if( src->ticket != NULL ) { dst->ticket = (unsigned char *) polarssl_malloc( src->ticket_len ); if( dst->ticket == NULL ) return( POLARSSL_ERR_SSL_MALLOC_FAILED ); memcpy( dst->ticket, src->ticket, src->ticket_len ); } #endif /* POLARSSL_SSL_SESSION_TICKETS */ return( 0 ); } #if defined(POLARSSL_SSL_HW_RECORD_ACCEL) int (*ssl_hw_record_init)( ssl_context *ssl, const unsigned char *key_enc, const unsigned char *key_dec, size_t keylen, const unsigned char *iv_enc, const unsigned char *iv_dec, size_t ivlen, const unsigned char *mac_enc, const unsigned char *mac_dec, size_t maclen ) = NULL; int (*ssl_hw_record_activate)( ssl_context *ssl, int direction) = NULL; int (*ssl_hw_record_reset)( ssl_context *ssl ) = NULL; int (*ssl_hw_record_write)( ssl_context *ssl ) = NULL; int (*ssl_hw_record_read)( ssl_context *ssl ) = NULL; int (*ssl_hw_record_finish)( ssl_context *ssl ) = NULL; #endif /* POLARSSL_SSL_HW_RECORD_ACCEL */ /* * Key material generation */ #if defined(POLARSSL_SSL_PROTO_SSL3) static int ssl3_prf( const unsigned char *secret, size_t slen, const char *label, const unsigned char *random, size_t rlen, unsigned char *dstbuf, size_t dlen ) { size_t i; md5_context md5; sha1_context sha1; unsigned char padding[16]; unsigned char sha1sum[20]; ((void)label); md5_init( &md5 ); sha1_init( &sha1 ); /* * SSLv3: * block = * MD5( secret + SHA1( 'A' + secret + random ) ) + * MD5( secret + SHA1( 'BB' + secret + random ) ) + * MD5( secret + SHA1( 'CCC' + secret + random ) ) + * ... */ for( i = 0; i < dlen / 16; i++ ) { memset( padding, (unsigned char) ('A' + i), 1 + i ); sha1_starts( &sha1 ); sha1_update( &sha1, padding, 1 + i ); sha1_update( &sha1, secret, slen ); sha1_update( &sha1, random, rlen ); sha1_finish( &sha1, sha1sum ); md5_starts( &md5 ); md5_update( &md5, secret, slen ); md5_update( &md5, sha1sum, 20 ); md5_finish( &md5, dstbuf + i * 16 ); } md5_free( &md5 ); sha1_free( &sha1 ); polarssl_zeroize( padding, sizeof( padding ) ); polarssl_zeroize( sha1sum, sizeof( sha1sum ) ); return( 0 ); } #endif /* POLARSSL_SSL_PROTO_SSL3 */ #if defined(POLARSSL_SSL_PROTO_TLS1) || defined(POLARSSL_SSL_PROTO_TLS1_1) static int tls1_prf( const unsigned char *secret, size_t slen, const char *label, const unsigned char *random, size_t rlen, unsigned char *dstbuf, size_t dlen ) { size_t nb, hs; size_t i, j, k; const unsigned char *S1, *S2; unsigned char tmp[128]; unsigned char h_i[20]; if( sizeof( tmp ) < 20 + strlen( label ) + rlen ) return( POLARSSL_ERR_SSL_BAD_INPUT_DATA ); hs = ( slen + 1 ) / 2; S1 = secret; S2 = secret + slen - hs; nb = strlen( label ); memcpy( tmp + 20, label, nb ); memcpy( tmp + 20 + nb, random, rlen ); nb += rlen; /* * First compute P_md5(secret,label+random)[0..dlen] */ md5_hmac( S1, hs, tmp + 20, nb, 4 + tmp ); for( i = 0; i < dlen; i += 16 ) { md5_hmac( S1, hs, 4 + tmp, 16 + nb, h_i ); md5_hmac( S1, hs, 4 + tmp, 16, 4 + tmp ); k = ( i + 16 > dlen ) ? dlen % 16 : 16; for( j = 0; j < k; j++ ) dstbuf[i + j] = h_i[j]; } /* * XOR out with P_sha1(secret,label+random)[0..dlen] */ sha1_hmac( S2, hs, tmp + 20, nb, tmp ); for( i = 0; i < dlen; i += 20 ) { sha1_hmac( S2, hs, tmp, 20 + nb, h_i ); sha1_hmac( S2, hs, tmp, 20, tmp ); k = ( i + 20 > dlen ) ? dlen % 20 : 20; for( j = 0; j < k; j++ ) dstbuf[i + j] = (unsigned char)( dstbuf[i + j] ^ h_i[j] ); } polarssl_zeroize( tmp, sizeof( tmp ) ); polarssl_zeroize( h_i, sizeof( h_i ) ); return( 0 ); } #endif /* POLARSSL_SSL_PROTO_TLS1) || POLARSSL_SSL_PROTO_TLS1_1 */ #if defined(POLARSSL_SSL_PROTO_TLS1_2) #if defined(POLARSSL_SHA256_C) static int tls_prf_sha256( const unsigned char *secret, size_t slen, const char *label, const unsigned char *random, size_t rlen, unsigned char *dstbuf, size_t dlen ) { size_t nb; size_t i, j, k; unsigned char tmp[128]; unsigned char h_i[32]; if( sizeof( tmp ) < 32 + strlen( label ) + rlen ) return( POLARSSL_ERR_SSL_BAD_INPUT_DATA ); nb = strlen( label ); memcpy( tmp + 32, label, nb ); memcpy( tmp + 32 + nb, random, rlen ); nb += rlen; /* * Compute P_(secret, label + random)[0..dlen] */ sha256_hmac( secret, slen, tmp + 32, nb, tmp, 0 ); for( i = 0; i < dlen; i += 32 ) { sha256_hmac( secret, slen, tmp, 32 + nb, h_i, 0 ); sha256_hmac( secret, slen, tmp, 32, tmp, 0 ); k = ( i + 32 > dlen ) ? dlen % 32 : 32; for( j = 0; j < k; j++ ) dstbuf[i + j] = h_i[j]; } polarssl_zeroize( tmp, sizeof( tmp ) ); polarssl_zeroize( h_i, sizeof( h_i ) ); return( 0 ); } #endif /* POLARSSL_SHA256_C */ #if defined(POLARSSL_SHA512_C) static int tls_prf_sha384( const unsigned char *secret, size_t slen, const char *label, const unsigned char *random, size_t rlen, unsigned char *dstbuf, size_t dlen ) { size_t nb; size_t i, j, k; unsigned char tmp[128]; unsigned char h_i[48]; if( sizeof( tmp ) < 48 + strlen( label ) + rlen ) return( POLARSSL_ERR_SSL_BAD_INPUT_DATA ); nb = strlen( label ); memcpy( tmp + 48, label, nb ); memcpy( tmp + 48 + nb, random, rlen ); nb += rlen; /* * Compute P_(secret, label + random)[0..dlen] */ sha512_hmac( secret, slen, tmp + 48, nb, tmp, 1 ); for( i = 0; i < dlen; i += 48 ) { sha512_hmac( secret, slen, tmp, 48 + nb, h_i, 1 ); sha512_hmac( secret, slen, tmp, 48, tmp, 1 ); k = ( i + 48 > dlen ) ? dlen % 48 : 48; for( j = 0; j < k; j++ ) dstbuf[i + j] = h_i[j]; } polarssl_zeroize( tmp, sizeof( tmp ) ); polarssl_zeroize( h_i, sizeof( h_i ) ); return( 0 ); } #endif /* POLARSSL_SHA512_C */ #endif /* POLARSSL_SSL_PROTO_TLS1_2 */ static void ssl_update_checksum_start( ssl_context *, const unsigned char *, size_t ); #if defined(POLARSSL_SSL_PROTO_SSL3) || defined(POLARSSL_SSL_PROTO_TLS1) || \ defined(POLARSSL_SSL_PROTO_TLS1_1) static void ssl_update_checksum_md5sha1( ssl_context *, const unsigned char *, size_t ); #endif #if defined(POLARSSL_SSL_PROTO_SSL3) static void ssl_calc_verify_ssl( ssl_context *, unsigned char * ); static void ssl_calc_finished_ssl( ssl_context *, unsigned char *, int ); #endif #if defined(POLARSSL_SSL_PROTO_TLS1) || defined(POLARSSL_SSL_PROTO_TLS1_1) static void ssl_calc_verify_tls( ssl_context *, unsigned char * ); static void ssl_calc_finished_tls( ssl_context *, unsigned char *, int ); #endif #if defined(POLARSSL_SSL_PROTO_TLS1_2) #if defined(POLARSSL_SHA256_C) static void ssl_update_checksum_sha256( ssl_context *, const unsigned char *, size_t ); static void ssl_calc_verify_tls_sha256( ssl_context *,unsigned char * ); static void ssl_calc_finished_tls_sha256( ssl_context *,unsigned char *, int ); #endif #if defined(POLARSSL_SHA512_C) static void ssl_update_checksum_sha384( ssl_context *, const unsigned char *, size_t ); static void ssl_calc_verify_tls_sha384( ssl_context *, unsigned char * ); static void ssl_calc_finished_tls_sha384( ssl_context *, unsigned char *, int ); #endif #endif /* POLARSSL_SSL_PROTO_TLS1_2 */ int ssl_derive_keys( ssl_context *ssl ) { int ret = 0; unsigned char tmp[64]; unsigned char keyblk[256]; unsigned char *key1; unsigned char *key2; unsigned char *mac_enc; unsigned char *mac_dec; size_t iv_copy_len; const cipher_info_t *cipher_info; const md_info_t *md_info; ssl_session *session = ssl->session_negotiate; ssl_transform *transform = ssl->transform_negotiate; ssl_handshake_params *handshake = ssl->handshake; SSL_DEBUG_MSG( 2, ( "=> derive keys" ) ); cipher_info = cipher_info_from_type( transform->ciphersuite_info->cipher ); if( cipher_info == NULL ) { SSL_DEBUG_MSG( 1, ( "cipher info for %d not found", transform->ciphersuite_info->cipher ) ); return( POLARSSL_ERR_SSL_BAD_INPUT_DATA ); } md_info = md_info_from_type( transform->ciphersuite_info->mac ); if( md_info == NULL ) { SSL_DEBUG_MSG( 1, ( "md info for %d not found", transform->ciphersuite_info->mac ) ); return( POLARSSL_ERR_SSL_BAD_INPUT_DATA ); } /* * Set appropriate PRF function and other SSL / TLS / TLS1.2 functions */ #if defined(POLARSSL_SSL_PROTO_SSL3) if( ssl->minor_ver == SSL_MINOR_VERSION_0 ) { handshake->tls_prf = ssl3_prf; handshake->calc_verify = ssl_calc_verify_ssl; handshake->calc_finished = ssl_calc_finished_ssl; } else #endif #if defined(POLARSSL_SSL_PROTO_TLS1) || defined(POLARSSL_SSL_PROTO_TLS1_1) if( ssl->minor_ver < SSL_MINOR_VERSION_3 ) { handshake->tls_prf = tls1_prf; handshake->calc_verify = ssl_calc_verify_tls; handshake->calc_finished = ssl_calc_finished_tls; } else #endif #if defined(POLARSSL_SSL_PROTO_TLS1_2) #if defined(POLARSSL_SHA512_C) if( ssl->minor_ver == SSL_MINOR_VERSION_3 && transform->ciphersuite_info->mac == POLARSSL_MD_SHA384 ) { handshake->tls_prf = tls_prf_sha384; handshake->calc_verify = ssl_calc_verify_tls_sha384; handshake->calc_finished = ssl_calc_finished_tls_sha384; } else #endif #if defined(POLARSSL_SHA256_C) if( ssl->minor_ver == SSL_MINOR_VERSION_3 ) { handshake->tls_prf = tls_prf_sha256; handshake->calc_verify = ssl_calc_verify_tls_sha256; handshake->calc_finished = ssl_calc_finished_tls_sha256; } else #endif #endif /* POLARSSL_SSL_PROTO_TLS1_2 */ { SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( POLARSSL_ERR_SSL_INTERNAL_ERROR ); } /* * SSLv3: * master = * MD5( premaster + SHA1( 'A' + premaster + randbytes ) ) + * MD5( premaster + SHA1( 'BB' + premaster + randbytes ) ) + * MD5( premaster + SHA1( 'CCC' + premaster + randbytes ) ) * * TLSv1+: * master = PRF( premaster, "master secret", randbytes )[0..47] */ if( handshake->resume == 0 ) { SSL_DEBUG_BUF( 3, "premaster secret", handshake->premaster, handshake->pmslen ); handshake->tls_prf( handshake->premaster, handshake->pmslen, "master secret", handshake->randbytes, 64, session->master, 48 ); polarssl_zeroize( handshake->premaster, sizeof(handshake->premaster) ); } else SSL_DEBUG_MSG( 3, ( "no premaster (session resumed)" ) ); /* * Swap the client and server random values. */ memcpy( tmp, handshake->randbytes, 64 ); memcpy( handshake->randbytes, tmp + 32, 32 ); memcpy( handshake->randbytes + 32, tmp, 32 ); polarssl_zeroize( tmp, sizeof( tmp ) ); /* * SSLv3: * key block = * MD5( master + SHA1( 'A' + master + randbytes ) ) + * MD5( master + SHA1( 'BB' + master + randbytes ) ) + * MD5( master + SHA1( 'CCC' + master + randbytes ) ) + * MD5( master + SHA1( 'DDDD' + master + randbytes ) ) + * ... * * TLSv1: * key block = PRF( master, "key expansion", randbytes ) */ handshake->tls_prf( session->master, 48, "key expansion", handshake->randbytes, 64, keyblk, 256 ); SSL_DEBUG_MSG( 3, ( "ciphersuite = %s", ssl_get_ciphersuite_name( session->ciphersuite ) ) ); SSL_DEBUG_BUF( 3, "master secret", session->master, 48 ); SSL_DEBUG_BUF( 4, "random bytes", handshake->randbytes, 64 ); SSL_DEBUG_BUF( 4, "key block", keyblk, 256 ); polarssl_zeroize( handshake->randbytes, sizeof( handshake->randbytes ) ); /* * Determine the appropriate key, IV and MAC length. */ transform->keylen = cipher_info->key_length / 8; if( cipher_info->mode == POLARSSL_MODE_GCM || cipher_info->mode == POLARSSL_MODE_CCM ) { transform->maclen = 0; transform->ivlen = 12; transform->fixed_ivlen = 4; /* Minimum length is expicit IV + tag */ transform->minlen = transform->ivlen - transform->fixed_ivlen + ( transform->ciphersuite_info->flags & POLARSSL_CIPHERSUITE_SHORT_TAG ? 8 : 16 ); } else { int ret; /* Initialize HMAC contexts */ if( ( ret = md_init_ctx( &transform->md_ctx_enc, md_info ) ) != 0 || ( ret = md_init_ctx( &transform->md_ctx_dec, md_info ) ) != 0 ) { SSL_DEBUG_RET( 1, "md_init_ctx", ret ); return( ret ); } /* Get MAC length */ transform->maclen = md_get_size( md_info ); #if defined(POLARSSL_SSL_TRUNCATED_HMAC) /* * If HMAC is to be truncated, we shall keep the leftmost bytes, * (rfc 6066 page 13 or rfc 2104 section 4), * so we only need to adjust the length here. */ if( session->trunc_hmac == SSL_TRUNC_HMAC_ENABLED ) transform->maclen = SSL_TRUNCATED_HMAC_LEN; #endif /* POLARSSL_SSL_TRUNCATED_HMAC */ /* IV length */ transform->ivlen = cipher_info->iv_size; /* Minimum length */ if( cipher_info->mode == POLARSSL_MODE_STREAM ) transform->minlen = transform->maclen; else { /* * GenericBlockCipher: * first multiple of blocklen greater than maclen * + IV except for SSL3 and TLS 1.0 */ transform->minlen = transform->maclen + cipher_info->block_size - transform->maclen % cipher_info->block_size; #if defined(POLARSSL_SSL_PROTO_SSL3) || defined(POLARSSL_SSL_PROTO_TLS1) if( ssl->minor_ver == SSL_MINOR_VERSION_0 || ssl->minor_ver == SSL_MINOR_VERSION_1 ) ; /* No need to adjust minlen */ else #endif #if defined(POLARSSL_SSL_PROTO_TLS1_1) || defined(POLARSSL_SSL_PROTO_TLS1_2) if( ssl->minor_ver == SSL_MINOR_VERSION_2 || ssl->minor_ver == SSL_MINOR_VERSION_3 ) { transform->minlen += transform->ivlen; } else #endif { SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( POLARSSL_ERR_SSL_INTERNAL_ERROR ); } } } SSL_DEBUG_MSG( 3, ( "keylen: %d, minlen: %d, ivlen: %d, maclen: %d", transform->keylen, transform->minlen, transform->ivlen, transform->maclen ) ); /* * Finally setup the cipher contexts, IVs and MAC secrets. */ if( ssl->endpoint == SSL_IS_CLIENT ) { key1 = keyblk + transform->maclen * 2; key2 = keyblk + transform->maclen * 2 + transform->keylen; mac_enc = keyblk; mac_dec = keyblk + transform->maclen; /* * This is not used in TLS v1.1. */ iv_copy_len = ( transform->fixed_ivlen ) ? transform->fixed_ivlen : transform->ivlen; memcpy( transform->iv_enc, key2 + transform->keylen, iv_copy_len ); memcpy( transform->iv_dec, key2 + transform->keylen + iv_copy_len, iv_copy_len ); } else { key1 = keyblk + transform->maclen * 2 + transform->keylen; key2 = keyblk + transform->maclen * 2; mac_enc = keyblk + transform->maclen; mac_dec = keyblk; /* * This is not used in TLS v1.1. */ iv_copy_len = ( transform->fixed_ivlen ) ? transform->fixed_ivlen : transform->ivlen; memcpy( transform->iv_dec, key1 + transform->keylen, iv_copy_len ); memcpy( transform->iv_enc, key1 + transform->keylen + iv_copy_len, iv_copy_len ); } #if defined(POLARSSL_SSL_PROTO_SSL3) if( ssl->minor_ver == SSL_MINOR_VERSION_0 ) { if( transform->maclen > sizeof transform->mac_enc ) { SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( POLARSSL_ERR_SSL_INTERNAL_ERROR ); } memcpy( transform->mac_enc, mac_enc, transform->maclen ); memcpy( transform->mac_dec, mac_dec, transform->maclen ); } else #endif /* POLARSSL_SSL_PROTO_SSL3 */ #if defined(POLARSSL_SSL_PROTO_TLS1) || defined(POLARSSL_SSL_PROTO_TLS1_1) || \ defined(POLARSSL_SSL_PROTO_TLS1_2) if( ssl->minor_ver >= SSL_MINOR_VERSION_1 ) { md_hmac_starts( &transform->md_ctx_enc, mac_enc, transform->maclen ); md_hmac_starts( &transform->md_ctx_dec, mac_dec, transform->maclen ); } else #endif { SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( POLARSSL_ERR_SSL_INTERNAL_ERROR ); } #if defined(POLARSSL_SSL_HW_RECORD_ACCEL) if( ssl_hw_record_init != NULL ) { int ret = 0; SSL_DEBUG_MSG( 2, ( "going for ssl_hw_record_init()" ) ); if( ( ret = ssl_hw_record_init( ssl, key1, key2, transform->keylen, transform->iv_enc, transform->iv_dec, iv_copy_len, mac_enc, mac_dec, transform->maclen ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_hw_record_init", ret ); return( POLARSSL_ERR_SSL_HW_ACCEL_FAILED ); } } #endif /* POLARSSL_SSL_HW_RECORD_ACCEL */ if( ( ret = cipher_init_ctx( &transform->cipher_ctx_enc, cipher_info ) ) != 0 ) { SSL_DEBUG_RET( 1, "cipher_init_ctx", ret ); return( ret ); } if( ( ret = cipher_init_ctx( &transform->cipher_ctx_dec, cipher_info ) ) != 0 ) { SSL_DEBUG_RET( 1, "cipher_init_ctx", ret ); return( ret ); } if( ( ret = cipher_setkey( &transform->cipher_ctx_enc, key1, cipher_info->key_length, POLARSSL_ENCRYPT ) ) != 0 ) { SSL_DEBUG_RET( 1, "cipher_setkey", ret ); return( ret ); } if( ( ret = cipher_setkey( &transform->cipher_ctx_dec, key2, cipher_info->key_length, POLARSSL_DECRYPT ) ) != 0 ) { SSL_DEBUG_RET( 1, "cipher_setkey", ret ); return( ret ); } #if defined(POLARSSL_CIPHER_MODE_CBC) if( cipher_info->mode == POLARSSL_MODE_CBC ) { if( ( ret = cipher_set_padding_mode( &transform->cipher_ctx_enc, POLARSSL_PADDING_NONE ) ) != 0 ) { SSL_DEBUG_RET( 1, "cipher_set_padding_mode", ret ); return( ret ); } if( ( ret = cipher_set_padding_mode( &transform->cipher_ctx_dec, POLARSSL_PADDING_NONE ) ) != 0 ) { SSL_DEBUG_RET( 1, "cipher_set_padding_mode", ret ); return( ret ); } } #endif /* POLARSSL_CIPHER_MODE_CBC */ polarssl_zeroize( keyblk, sizeof( keyblk ) ); #if defined(POLARSSL_ZLIB_SUPPORT) // Initialize compression // if( session->compression == SSL_COMPRESS_DEFLATE ) { if( ssl->compress_buf == NULL ) { SSL_DEBUG_MSG( 3, ( "Allocating compression buffer" ) ); ssl->compress_buf = polarssl_malloc( SSL_BUFFER_LEN ); if( ssl->compress_buf == NULL ) { SSL_DEBUG_MSG( 1, ( "malloc(%d bytes) failed", SSL_BUFFER_LEN ) ); return( POLARSSL_ERR_SSL_MALLOC_FAILED ); } } SSL_DEBUG_MSG( 3, ( "Initializing zlib states" ) ); memset( &transform->ctx_deflate, 0, sizeof( transform->ctx_deflate ) ); memset( &transform->ctx_inflate, 0, sizeof( transform->ctx_inflate ) ); if( deflateInit( &transform->ctx_deflate, Z_DEFAULT_COMPRESSION ) != Z_OK || inflateInit( &transform->ctx_inflate ) != Z_OK ) { SSL_DEBUG_MSG( 1, ( "Failed to initialize compression" ) ); return( POLARSSL_ERR_SSL_COMPRESSION_FAILED ); } } #endif /* POLARSSL_ZLIB_SUPPORT */ SSL_DEBUG_MSG( 2, ( "<= derive keys" ) ); return( 0 ); } #if defined(POLARSSL_SSL_PROTO_SSL3) void ssl_calc_verify_ssl( ssl_context *ssl, unsigned char hash[36] ) { md5_context md5; sha1_context sha1; unsigned char pad_1[48]; unsigned char pad_2[48]; SSL_DEBUG_MSG( 2, ( "=> calc verify ssl" ) ); memcpy( &md5 , &ssl->handshake->fin_md5 , sizeof(md5_context) ); memcpy( &sha1, &ssl->handshake->fin_sha1, sizeof(sha1_context) ); memset( pad_1, 0x36, 48 ); memset( pad_2, 0x5C, 48 ); md5_update( &md5, ssl->session_negotiate->master, 48 ); md5_update( &md5, pad_1, 48 ); md5_finish( &md5, hash ); md5_starts( &md5 ); md5_update( &md5, ssl->session_negotiate->master, 48 ); md5_update( &md5, pad_2, 48 ); md5_update( &md5, hash, 16 ); md5_finish( &md5, hash ); sha1_update( &sha1, ssl->session_negotiate->master, 48 ); sha1_update( &sha1, pad_1, 40 ); sha1_finish( &sha1, hash + 16 ); sha1_starts( &sha1 ); sha1_update( &sha1, ssl->session_negotiate->master, 48 ); sha1_update( &sha1, pad_2, 40 ); sha1_update( &sha1, hash + 16, 20 ); sha1_finish( &sha1, hash + 16 ); SSL_DEBUG_BUF( 3, "calculated verify result", hash, 36 ); SSL_DEBUG_MSG( 2, ( "<= calc verify" ) ); md5_free( &md5 ); sha1_free( &sha1 ); return; } #endif /* POLARSSL_SSL_PROTO_SSL3 */ #if defined(POLARSSL_SSL_PROTO_TLS1) || defined(POLARSSL_SSL_PROTO_TLS1_1) void ssl_calc_verify_tls( ssl_context *ssl, unsigned char hash[36] ) { md5_context md5; sha1_context sha1; SSL_DEBUG_MSG( 2, ( "=> calc verify tls" ) ); memcpy( &md5 , &ssl->handshake->fin_md5 , sizeof(md5_context) ); memcpy( &sha1, &ssl->handshake->fin_sha1, sizeof(sha1_context) ); md5_finish( &md5, hash ); sha1_finish( &sha1, hash + 16 ); SSL_DEBUG_BUF( 3, "calculated verify result", hash, 36 ); SSL_DEBUG_MSG( 2, ( "<= calc verify" ) ); md5_free( &md5 ); sha1_free( &sha1 ); return; } #endif /* POLARSSL_SSL_PROTO_TLS1 || POLARSSL_SSL_PROTO_TLS1_1 */ #if defined(POLARSSL_SSL_PROTO_TLS1_2) #if defined(POLARSSL_SHA256_C) void ssl_calc_verify_tls_sha256( ssl_context *ssl, unsigned char hash[32] ) { sha256_context sha256; SSL_DEBUG_MSG( 2, ( "=> calc verify sha256" ) ); memcpy( &sha256, &ssl->handshake->fin_sha256, sizeof(sha256_context) ); sha256_finish( &sha256, hash ); SSL_DEBUG_BUF( 3, "calculated verify result", hash, 32 ); SSL_DEBUG_MSG( 2, ( "<= calc verify" ) ); sha256_free( &sha256 ); return; } #endif /* POLARSSL_SHA256_C */ #if defined(POLARSSL_SHA512_C) void ssl_calc_verify_tls_sha384( ssl_context *ssl, unsigned char hash[48] ) { sha512_context sha512; SSL_DEBUG_MSG( 2, ( "=> calc verify sha384" ) ); memcpy( &sha512, &ssl->handshake->fin_sha512, sizeof(sha512_context) ); sha512_finish( &sha512, hash ); SSL_DEBUG_BUF( 3, "calculated verify result", hash, 48 ); SSL_DEBUG_MSG( 2, ( "<= calc verify" ) ); sha512_free( &sha512 ); return; } #endif /* POLARSSL_SHA512_C */ #endif /* POLARSSL_SSL_PROTO_TLS1_2 */ #if defined(POLARSSL_KEY_EXCHANGE__SOME__PSK_ENABLED) int ssl_psk_derive_premaster( ssl_context *ssl, key_exchange_type_t key_ex ) { unsigned char *p = ssl->handshake->premaster; unsigned char *end = p + sizeof( ssl->handshake->premaster ); /* * PMS = struct { * opaque other_secret<0..2^16-1>; * opaque psk<0..2^16-1>; * }; * with "other_secret" depending on the particular key exchange */ #if defined(POLARSSL_KEY_EXCHANGE_PSK_ENABLED) if( key_ex == POLARSSL_KEY_EXCHANGE_PSK ) { if( end - p < 2 + (int) ssl->psk_len ) return( POLARSSL_ERR_SSL_BAD_INPUT_DATA ); *(p++) = (unsigned char)( ssl->psk_len >> 8 ); *(p++) = (unsigned char)( ssl->psk_len ); p += ssl->psk_len; } else #endif /* POLARSSL_KEY_EXCHANGE_PSK_ENABLED */ #if defined(POLARSSL_KEY_EXCHANGE_RSA_PSK_ENABLED) if( key_ex == POLARSSL_KEY_EXCHANGE_RSA_PSK ) { /* * other_secret already set by the ClientKeyExchange message, * and is 48 bytes long */ *p++ = 0; *p++ = 48; p += 48; } else #endif /* POLARSSL_KEY_EXCHANGE_RSA_PKS_ENABLED */ #if defined(POLARSSL_KEY_EXCHANGE_DHE_PSK_ENABLED) if( key_ex == POLARSSL_KEY_EXCHANGE_DHE_PSK ) { int ret; size_t len = end - ( p + 2 ); /* Write length only when we know the actual value */ if( ( ret = dhm_calc_secret( &ssl->handshake->dhm_ctx, p + 2, &len, ssl->f_rng, ssl->p_rng ) ) != 0 ) { SSL_DEBUG_RET( 1, "dhm_calc_secret", ret ); return( ret ); } *(p++) = (unsigned char)( len >> 8 ); *(p++) = (unsigned char)( len ); p += len; SSL_DEBUG_MPI( 3, "DHM: K ", &ssl->handshake->dhm_ctx.K ); } else #endif /* POLARSSL_KEY_EXCHANGE_DHE_PSK_ENABLED */ #if defined(POLARSSL_KEY_EXCHANGE_ECDHE_PSK_ENABLED) if( key_ex == POLARSSL_KEY_EXCHANGE_ECDHE_PSK ) { int ret; size_t zlen; if( ( ret = ecdh_calc_secret( &ssl->handshake->ecdh_ctx, &zlen, p + 2, end - ( p + 2 ), ssl->f_rng, ssl->p_rng ) ) != 0 ) { SSL_DEBUG_RET( 1, "ecdh_calc_secret", ret ); return( ret ); } *(p++) = (unsigned char)( zlen >> 8 ); *(p++) = (unsigned char)( zlen ); p += zlen; SSL_DEBUG_MPI( 3, "ECDH: z", &ssl->handshake->ecdh_ctx.z ); } else #endif /* POLARSSL_KEY_EXCHANGE_ECDHE_PSK_ENABLED */ { SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( POLARSSL_ERR_SSL_INTERNAL_ERROR ); } /* opaque psk<0..2^16-1>; */ if( end - p < 2 + (int) ssl->psk_len ) return( POLARSSL_ERR_SSL_BAD_INPUT_DATA ); *(p++) = (unsigned char)( ssl->psk_len >> 8 ); *(p++) = (unsigned char)( ssl->psk_len ); memcpy( p, ssl->psk, ssl->psk_len ); p += ssl->psk_len; ssl->handshake->pmslen = p - ssl->handshake->premaster; return( 0 ); } #endif /* POLARSSL_KEY_EXCHANGE__SOME__PSK_ENABLED */ #if defined(POLARSSL_SSL_PROTO_SSL3) /* * SSLv3.0 MAC functions */ static void ssl_mac( md_context_t *md_ctx, unsigned char *secret, unsigned char *buf, size_t len, unsigned char *ctr, int type ) { unsigned char header[11]; unsigned char padding[48]; int padlen; int md_size = md_get_size( md_ctx->md_info ); int md_type = md_get_type( md_ctx->md_info ); /* Only MD5 and SHA-1 supported */ if( md_type == POLARSSL_MD_MD5 ) padlen = 48; else padlen = 40; memcpy( header, ctr, 8 ); header[ 8] = (unsigned char) type; header[ 9] = (unsigned char)( len >> 8 ); header[10] = (unsigned char)( len ); memset( padding, 0x36, padlen ); md_starts( md_ctx ); md_update( md_ctx, secret, md_size ); md_update( md_ctx, padding, padlen ); md_update( md_ctx, header, 11 ); md_update( md_ctx, buf, len ); md_finish( md_ctx, buf + len ); memset( padding, 0x5C, padlen ); md_starts( md_ctx ); md_update( md_ctx, secret, md_size ); md_update( md_ctx, padding, padlen ); md_update( md_ctx, buf + len, md_size ); md_finish( md_ctx, buf + len ); } #endif /* POLARSSL_SSL_PROTO_SSL3 */ /* * Encryption/decryption functions */ static int ssl_encrypt_buf( ssl_context *ssl ) { const cipher_mode_t mode = cipher_get_cipher_mode( &ssl->transform_out->cipher_ctx_enc ); SSL_DEBUG_MSG( 2, ( "=> encrypt buf" ) ); /* * Add MAC before encrypt, except for AEAD modes */ #if defined(POLARSSL_ARC4_C) || defined(POLARSSL_CIPHER_NULL_CIPHER) || \ ( defined(POLARSSL_CIPHER_MODE_CBC) && \ ( defined(POLARSSL_AES_C) || defined(POLARSSL_CAMELLIA_C) ) ) if( mode != POLARSSL_MODE_GCM && mode != POLARSSL_MODE_CCM ) { #if defined(POLARSSL_SSL_PROTO_SSL3) if( ssl->minor_ver == SSL_MINOR_VERSION_0 ) { ssl_mac( &ssl->transform_out->md_ctx_enc, ssl->transform_out->mac_enc, ssl->out_msg, ssl->out_msglen, ssl->out_ctr, ssl->out_msgtype ); } else #endif #if defined(POLARSSL_SSL_PROTO_TLS1) || defined(POLARSSL_SSL_PROTO_TLS1_1) || \ defined(POLARSSL_SSL_PROTO_TLS1_2) if( ssl->minor_ver >= SSL_MINOR_VERSION_1 ) { md_hmac_update( &ssl->transform_out->md_ctx_enc, ssl->out_ctr, 8 ); md_hmac_update( &ssl->transform_out->md_ctx_enc, ssl->out_hdr, 3 ); md_hmac_update( &ssl->transform_out->md_ctx_enc, ssl->out_len, 2 ); md_hmac_update( &ssl->transform_out->md_ctx_enc, ssl->out_msg, ssl->out_msglen ); md_hmac_finish( &ssl->transform_out->md_ctx_enc, ssl->out_msg + ssl->out_msglen ); md_hmac_reset( &ssl->transform_out->md_ctx_enc ); } else #endif { SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( POLARSSL_ERR_SSL_INTERNAL_ERROR ); } SSL_DEBUG_BUF( 4, "computed mac", ssl->out_msg + ssl->out_msglen, ssl->transform_out->maclen ); ssl->out_msglen += ssl->transform_out->maclen; } #endif /* AEAD not the only option */ /* * Encrypt */ #if defined(POLARSSL_ARC4_C) || defined(POLARSSL_CIPHER_NULL_CIPHER) if( mode == POLARSSL_MODE_STREAM ) { int ret; size_t olen = 0; SSL_DEBUG_MSG( 3, ( "before encrypt: msglen = %d, " "including %d bytes of padding", ssl->out_msglen, 0 ) ); SSL_DEBUG_BUF( 4, "before encrypt: output payload", ssl->out_msg, ssl->out_msglen ); if( ( ret = cipher_crypt( &ssl->transform_out->cipher_ctx_enc, ssl->transform_out->iv_enc, ssl->transform_out->ivlen, ssl->out_msg, ssl->out_msglen, ssl->out_msg, &olen ) ) != 0 ) { SSL_DEBUG_RET( 1, "cipher_crypt", ret ); return( ret ); } if( ssl->out_msglen != olen ) { SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( POLARSSL_ERR_SSL_INTERNAL_ERROR ); } } else #endif /* POLARSSL_ARC4_C || POLARSSL_CIPHER_NULL_CIPHER */ #if defined(POLARSSL_GCM_C) || defined(POLARSSL_CCM_C) if( mode == POLARSSL_MODE_GCM || mode == POLARSSL_MODE_CCM ) { int ret; size_t enc_msglen, olen; unsigned char *enc_msg; unsigned char add_data[13]; unsigned char taglen = ssl->transform_out->ciphersuite_info->flags & POLARSSL_CIPHERSUITE_SHORT_TAG ? 8 : 16; memcpy( add_data, ssl->out_ctr, 8 ); add_data[8] = ssl->out_msgtype; ssl_write_version( ssl->major_ver, ssl->minor_ver, ssl->transport, add_data + 9 ); add_data[11] = ( ssl->out_msglen >> 8 ) & 0xFF; add_data[12] = ssl->out_msglen & 0xFF; SSL_DEBUG_BUF( 4, "additional data used for AEAD", add_data, 13 ); /* * Generate IV */ ret = ssl->f_rng( ssl->p_rng, ssl->transform_out->iv_enc + ssl->transform_out->fixed_ivlen, ssl->transform_out->ivlen - ssl->transform_out->fixed_ivlen ); if( ret != 0 ) return( ret ); memcpy( ssl->out_iv, ssl->transform_out->iv_enc + ssl->transform_out->fixed_ivlen, ssl->transform_out->ivlen - ssl->transform_out->fixed_ivlen ); SSL_DEBUG_BUF( 4, "IV used", ssl->out_iv, ssl->transform_out->ivlen - ssl->transform_out->fixed_ivlen ); /* * Fix pointer positions and message length with added IV */ enc_msg = ssl->out_msg; enc_msglen = ssl->out_msglen; ssl->out_msglen += ssl->transform_out->ivlen - ssl->transform_out->fixed_ivlen; SSL_DEBUG_MSG( 3, ( "before encrypt: msglen = %d, " "including %d bytes of padding", ssl->out_msglen, 0 ) ); SSL_DEBUG_BUF( 4, "before encrypt: output payload", ssl->out_msg, ssl->out_msglen ); /* * Encrypt and authenticate */ if( ( ret = cipher_auth_encrypt( &ssl->transform_out->cipher_ctx_enc, ssl->transform_out->iv_enc, ssl->transform_out->ivlen, add_data, 13, enc_msg, enc_msglen, enc_msg, &olen, enc_msg + enc_msglen, taglen ) ) != 0 ) { SSL_DEBUG_RET( 1, "cipher_auth_encrypt", ret ); return( ret ); } if( olen != enc_msglen ) { SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( POLARSSL_ERR_SSL_INTERNAL_ERROR ); } ssl->out_msglen += taglen; SSL_DEBUG_BUF( 4, "after encrypt: tag", enc_msg + enc_msglen, taglen ); } else #endif /* POLARSSL_GCM_C || POLARSSL_CCM_C */ #if defined(POLARSSL_CIPHER_MODE_CBC) && \ ( defined(POLARSSL_AES_C) || defined(POLARSSL_CAMELLIA_C) ) if( mode == POLARSSL_MODE_CBC ) { int ret; unsigned char *enc_msg; size_t enc_msglen, padlen, olen = 0, i; padlen = ssl->transform_out->ivlen - ( ssl->out_msglen + 1 ) % ssl->transform_out->ivlen; if( padlen == ssl->transform_out->ivlen ) padlen = 0; for( i = 0; i <= padlen; i++ ) ssl->out_msg[ssl->out_msglen + i] = (unsigned char) padlen; ssl->out_msglen += padlen + 1; enc_msglen = ssl->out_msglen; enc_msg = ssl->out_msg; #if defined(POLARSSL_SSL_PROTO_TLS1_1) || defined(POLARSSL_SSL_PROTO_TLS1_2) /* * Prepend per-record IV for block cipher in TLS v1.1 and up as per * Method 1 (6.2.3.2. in RFC4346 and RFC5246) */ if( ssl->minor_ver >= SSL_MINOR_VERSION_2 ) { /* * Generate IV */ int ret = ssl->f_rng( ssl->p_rng, ssl->transform_out->iv_enc, ssl->transform_out->ivlen ); if( ret != 0 ) return( ret ); memcpy( ssl->out_iv, ssl->transform_out->iv_enc, ssl->transform_out->ivlen ); /* * Fix pointer positions and message length with added IV */ enc_msg = ssl->out_msg; enc_msglen = ssl->out_msglen; ssl->out_msglen += ssl->transform_out->ivlen; } #endif /* POLARSSL_SSL_PROTO_TLS1_1 || POLARSSL_SSL_PROTO_TLS1_2 */ SSL_DEBUG_MSG( 3, ( "before encrypt: msglen = %d, " "including %d bytes of IV and %d bytes of padding", ssl->out_msglen, ssl->transform_out->ivlen, padlen + 1 ) ); SSL_DEBUG_BUF( 4, "before encrypt: output payload", ssl->out_iv, ssl->out_msglen ); if( ( ret = cipher_crypt( &ssl->transform_out->cipher_ctx_enc, ssl->transform_out->iv_enc, ssl->transform_out->ivlen, enc_msg, enc_msglen, enc_msg, &olen ) ) != 0 ) { SSL_DEBUG_RET( 1, "cipher_crypt", ret ); return( ret ); } if( enc_msglen != olen ) { SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( POLARSSL_ERR_SSL_INTERNAL_ERROR ); } #if defined(POLARSSL_SSL_PROTO_SSL3) || defined(POLARSSL_SSL_PROTO_TLS1) if( ssl->minor_ver < SSL_MINOR_VERSION_2 ) { /* * Save IV in SSL3 and TLS1 */ memcpy( ssl->transform_out->iv_enc, ssl->transform_out->cipher_ctx_enc.iv, ssl->transform_out->ivlen ); } #endif } else #endif /* POLARSSL_CIPHER_MODE_CBC && ( POLARSSL_AES_C || POLARSSL_CAMELLIA_C ) */ { SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( POLARSSL_ERR_SSL_INTERNAL_ERROR ); } SSL_DEBUG_MSG( 2, ( "<= encrypt buf" ) ); return( 0 ); } #define POLARSSL_SSL_MAX_MAC_SIZE 48 static int ssl_decrypt_buf( ssl_context *ssl ) { size_t i; const cipher_mode_t mode = cipher_get_cipher_mode( &ssl->transform_in->cipher_ctx_dec ); #if defined(POLARSSL_ARC4_C) || defined(POLARSSL_CIPHER_NULL_CIPHER) || \ ( defined(POLARSSL_CIPHER_MODE_CBC) && \ ( defined(POLARSSL_AES_C) || defined(POLARSSL_CAMELLIA_C) ) ) size_t padlen = 0, correct = 1; #endif SSL_DEBUG_MSG( 2, ( "=> decrypt buf" ) ); if( ssl->in_msglen < ssl->transform_in->minlen ) { SSL_DEBUG_MSG( 1, ( "in_msglen (%d) < minlen (%d)", ssl->in_msglen, ssl->transform_in->minlen ) ); return( POLARSSL_ERR_SSL_INVALID_MAC ); } #if defined(POLARSSL_ARC4_C) || defined(POLARSSL_CIPHER_NULL_CIPHER) if( mode == POLARSSL_MODE_STREAM ) { int ret; size_t olen = 0; padlen = 0; if( ( ret = cipher_crypt( &ssl->transform_in->cipher_ctx_dec, ssl->transform_in->iv_dec, ssl->transform_in->ivlen, ssl->in_msg, ssl->in_msglen, ssl->in_msg, &olen ) ) != 0 ) { SSL_DEBUG_RET( 1, "cipher_crypt", ret ); return( ret ); } if( ssl->in_msglen != olen ) { SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( POLARSSL_ERR_SSL_INTERNAL_ERROR ); } } else #endif /* POLARSSL_ARC4_C || POLARSSL_CIPHER_NULL_CIPHER */ #if defined(POLARSSL_GCM_C) || defined(POLARSSL_CCM_C) if( mode == POLARSSL_MODE_GCM || mode == POLARSSL_MODE_CCM ) { int ret; size_t dec_msglen, olen; unsigned char *dec_msg; unsigned char *dec_msg_result; unsigned char add_data[13]; unsigned char taglen = ssl->transform_in->ciphersuite_info->flags & POLARSSL_CIPHERSUITE_SHORT_TAG ? 8 : 16; unsigned char explicit_iv_len = ssl->transform_in->ivlen - ssl->transform_in->fixed_ivlen; if( ssl->in_msglen < explicit_iv_len + taglen ) { SSL_DEBUG_MSG( 1, ( "msglen (%d) < explicit_iv_len (%d) " "+ taglen (%d)", ssl->in_msglen, explicit_iv_len, taglen ) ); return( POLARSSL_ERR_SSL_INVALID_MAC ); } dec_msglen = ssl->in_msglen - explicit_iv_len - taglen; dec_msg = ssl->in_msg; dec_msg_result = ssl->in_msg; ssl->in_msglen = dec_msglen; memcpy( add_data, ssl->in_ctr, 8 ); add_data[8] = ssl->in_msgtype; ssl_write_version( ssl->major_ver, ssl->minor_ver, ssl->transport, add_data + 9 ); add_data[11] = ( ssl->in_msglen >> 8 ) & 0xFF; add_data[12] = ssl->in_msglen & 0xFF; SSL_DEBUG_BUF( 4, "additional data used for AEAD", add_data, 13 ); memcpy( ssl->transform_in->iv_dec + ssl->transform_in->fixed_ivlen, ssl->in_iv, ssl->transform_in->ivlen - ssl->transform_in->fixed_ivlen ); SSL_DEBUG_BUF( 4, "IV used", ssl->transform_in->iv_dec, ssl->transform_in->ivlen ); SSL_DEBUG_BUF( 4, "TAG used", dec_msg + dec_msglen, taglen ); /* * Decrypt and authenticate */ if( ( ret = cipher_auth_decrypt( &ssl->transform_in->cipher_ctx_dec, ssl->transform_in->iv_dec, ssl->transform_in->ivlen, add_data, 13, dec_msg, dec_msglen, dec_msg_result, &olen, dec_msg + dec_msglen, taglen ) ) != 0 ) { SSL_DEBUG_RET( 1, "cipher_auth_decrypt", ret ); if( ret == POLARSSL_ERR_CIPHER_AUTH_FAILED ) return( POLARSSL_ERR_SSL_INVALID_MAC ); return( ret ); } if( olen != dec_msglen ) { SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( POLARSSL_ERR_SSL_INTERNAL_ERROR ); } } else #endif /* POLARSSL_GCM_C || POLARSSL_CCM_C */ #if defined(POLARSSL_CIPHER_MODE_CBC) && \ ( defined(POLARSSL_AES_C) || defined(POLARSSL_CAMELLIA_C) ) if( mode == POLARSSL_MODE_CBC ) { /* * Decrypt and check the padding */ int ret; unsigned char *dec_msg; unsigned char *dec_msg_result; size_t dec_msglen; size_t minlen = 0; size_t olen = 0; /* * Check immediate ciphertext sanity */ if( ssl->in_msglen % ssl->transform_in->ivlen != 0 ) { SSL_DEBUG_MSG( 1, ( "msglen (%d) %% ivlen (%d) != 0", ssl->in_msglen, ssl->transform_in->ivlen ) ); return( POLARSSL_ERR_SSL_INVALID_MAC ); } #if defined(POLARSSL_SSL_PROTO_TLS1_1) || defined(POLARSSL_SSL_PROTO_TLS1_2) if( ssl->minor_ver >= SSL_MINOR_VERSION_2 ) minlen += ssl->transform_in->ivlen; #endif if( ssl->in_msglen < minlen + ssl->transform_in->ivlen || ssl->in_msglen < minlen + ssl->transform_in->maclen + 1 ) { SSL_DEBUG_MSG( 1, ( "msglen (%d) < max( ivlen(%d), maclen (%d) " "+ 1 ) ( + expl IV )", ssl->in_msglen, ssl->transform_in->ivlen, ssl->transform_in->maclen ) ); return( POLARSSL_ERR_SSL_INVALID_MAC ); } dec_msglen = ssl->in_msglen; dec_msg = ssl->in_msg; dec_msg_result = ssl->in_msg; #if defined(POLARSSL_SSL_PROTO_TLS1_1) || defined(POLARSSL_SSL_PROTO_TLS1_2) /* * Initialize for prepended IV for block cipher in TLS v1.1 and up */ if( ssl->minor_ver >= SSL_MINOR_VERSION_2 ) { dec_msglen -= ssl->transform_in->ivlen; ssl->in_msglen -= ssl->transform_in->ivlen; for( i = 0; i < ssl->transform_in->ivlen; i++ ) ssl->transform_in->iv_dec[i] = ssl->in_iv[i]; } #endif /* POLARSSL_SSL_PROTO_TLS1_1 || POLARSSL_SSL_PROTO_TLS1_2 */ if( ( ret = cipher_crypt( &ssl->transform_in->cipher_ctx_dec, ssl->transform_in->iv_dec, ssl->transform_in->ivlen, dec_msg, dec_msglen, dec_msg_result, &olen ) ) != 0 ) { SSL_DEBUG_RET( 1, "cipher_crypt", ret ); return( ret ); } if( dec_msglen != olen ) { SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( POLARSSL_ERR_SSL_INTERNAL_ERROR ); } #if defined(POLARSSL_SSL_PROTO_SSL3) || defined(POLARSSL_SSL_PROTO_TLS1) if( ssl->minor_ver < SSL_MINOR_VERSION_2 ) { /* * Save IV in SSL3 and TLS1 */ memcpy( ssl->transform_in->iv_dec, ssl->transform_in->cipher_ctx_dec.iv, ssl->transform_in->ivlen ); } #endif padlen = 1 + ssl->in_msg[ssl->in_msglen - 1]; if( ssl->in_msglen < ssl->transform_in->maclen + padlen ) { #if defined(POLARSSL_SSL_DEBUG_ALL) SSL_DEBUG_MSG( 1, ( "msglen (%d) < maclen (%d) + padlen (%d)", ssl->in_msglen, ssl->transform_in->maclen, padlen ) ); #endif padlen = 0; correct = 0; } #if defined(POLARSSL_SSL_PROTO_SSL3) if( ssl->minor_ver == SSL_MINOR_VERSION_0 ) { if( padlen > ssl->transform_in->ivlen ) { #if defined(POLARSSL_SSL_DEBUG_ALL) SSL_DEBUG_MSG( 1, ( "bad padding length: is %d, " "should be no more than %d", padlen, ssl->transform_in->ivlen ) ); #endif correct = 0; } } else #endif /* POLARSSL_SSL_PROTO_SSL3 */ #if defined(POLARSSL_SSL_PROTO_TLS1) || defined(POLARSSL_SSL_PROTO_TLS1_1) || \ defined(POLARSSL_SSL_PROTO_TLS1_2) if( ssl->minor_ver > SSL_MINOR_VERSION_0 ) { /* * TLSv1+: always check the padding up to the first failure * and fake check up to 256 bytes of padding */ size_t pad_count = 0, real_count = 1; size_t padding_idx = ssl->in_msglen - padlen - 1; /* * Padding is guaranteed to be incorrect if: * 1. padlen >= ssl->in_msglen * * 2. padding_idx >= SSL_MAX_CONTENT_LEN + * ssl->transform_in->maclen * * In both cases we reset padding_idx to a safe value (0) to * prevent out-of-buffer reads. */ correct &= ( ssl->in_msglen >= padlen + 1 ); correct &= ( padding_idx < SSL_MAX_CONTENT_LEN + ssl->transform_in->maclen ); padding_idx *= correct; for( i = 1; i <= 256; i++ ) { real_count &= ( i <= padlen ); pad_count += real_count * ( ssl->in_msg[padding_idx + i] == padlen - 1 ); } correct &= ( pad_count == padlen ); /* Only 1 on correct padding */ #if defined(POLARSSL_SSL_DEBUG_ALL) if( padlen > 0 && correct == 0 ) SSL_DEBUG_MSG( 1, ( "bad padding byte detected" ) ); #endif padlen &= correct * 0x1FF; } else #endif /* POLARSSL_SSL_PROTO_TLS1 || POLARSSL_SSL_PROTO_TLS1_1 || \ POLARSSL_SSL_PROTO_TLS1_2 */ { SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( POLARSSL_ERR_SSL_INTERNAL_ERROR ); } } else #endif /* POLARSSL_CIPHER_MODE_CBC && ( POLARSSL_AES_C || POLARSSL_CAMELLIA_C ) */ { SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( POLARSSL_ERR_SSL_INTERNAL_ERROR ); } SSL_DEBUG_BUF( 4, "raw buffer after decryption", ssl->in_msg, ssl->in_msglen ); /* * Always compute the MAC (RFC4346, CBCTIME), except for AEAD of course */ #if defined(POLARSSL_ARC4_C) || defined(POLARSSL_CIPHER_NULL_CIPHER) || \ ( defined(POLARSSL_CIPHER_MODE_CBC) && \ ( defined(POLARSSL_AES_C) || defined(POLARSSL_CAMELLIA_C) ) ) if( mode != POLARSSL_MODE_GCM && mode != POLARSSL_MODE_CCM ) { unsigned char tmp[POLARSSL_SSL_MAX_MAC_SIZE]; ssl->in_msglen -= ( ssl->transform_in->maclen + padlen ); ssl->in_len[0] = (unsigned char)( ssl->in_msglen >> 8 ); ssl->in_len[1] = (unsigned char)( ssl->in_msglen ); memcpy( tmp, ssl->in_msg + ssl->in_msglen, ssl->transform_in->maclen ); #if defined(POLARSSL_SSL_PROTO_SSL3) if( ssl->minor_ver == SSL_MINOR_VERSION_0 ) { ssl_mac( &ssl->transform_in->md_ctx_dec, ssl->transform_in->mac_dec, ssl->in_msg, ssl->in_msglen, ssl->in_ctr, ssl->in_msgtype ); } else #endif /* POLARSSL_SSL_PROTO_SSL3 */ #if defined(POLARSSL_SSL_PROTO_TLS1) || defined(POLARSSL_SSL_PROTO_TLS1_1) || \ defined(POLARSSL_SSL_PROTO_TLS1_2) if( ssl->minor_ver > SSL_MINOR_VERSION_0 ) { /* * Process MAC and always update for padlen afterwards to make * total time independent of padlen * * extra_run compensates MAC check for padlen * * Known timing attacks: * - Lucky Thirteen (http://www.isg.rhul.ac.uk/tls/TLStiming.pdf) * * We use ( ( Lx + 8 ) / 64 ) to handle 'negative Lx' values * correctly. (We round down instead of up, so -56 is the correct * value for our calculations instead of -55) */ size_t j, extra_run = 0; extra_run = ( 13 + ssl->in_msglen + padlen + 8 ) / 64 - ( 13 + ssl->in_msglen + 8 ) / 64; extra_run &= correct * 0xFF; md_hmac_update( &ssl->transform_in->md_ctx_dec, ssl->in_ctr, 8 ); md_hmac_update( &ssl->transform_in->md_ctx_dec, ssl->in_hdr, 3 ); md_hmac_update( &ssl->transform_in->md_ctx_dec, ssl->in_len, 2 ); md_hmac_update( &ssl->transform_in->md_ctx_dec, ssl->in_msg, ssl->in_msglen ); md_hmac_finish( &ssl->transform_in->md_ctx_dec, ssl->in_msg + ssl->in_msglen ); for( j = 0; j < extra_run; j++ ) md_process( &ssl->transform_in->md_ctx_dec, ssl->in_msg ); md_hmac_reset( &ssl->transform_in->md_ctx_dec ); } else #endif /* POLARSSL_SSL_PROTO_TLS1 || POLARSSL_SSL_PROTO_TLS1_1 || \ POLARSSL_SSL_PROTO_TLS1_2 */ { SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( POLARSSL_ERR_SSL_INTERNAL_ERROR ); } SSL_DEBUG_BUF( 4, "message mac", tmp, ssl->transform_in->maclen ); SSL_DEBUG_BUF( 4, "computed mac", ssl->in_msg + ssl->in_msglen, ssl->transform_in->maclen ); if( safer_memcmp( tmp, ssl->in_msg + ssl->in_msglen, ssl->transform_in->maclen ) != 0 ) { #if defined(POLARSSL_SSL_DEBUG_ALL) SSL_DEBUG_MSG( 1, ( "message mac does not match" ) ); #endif correct = 0; } /* * Finally check the correct flag */ if( correct == 0 ) return( POLARSSL_ERR_SSL_INVALID_MAC ); } #endif /* AEAD not the only option */ if( ssl->in_msglen == 0 ) { ssl->nb_zero++; /* * Three or more empty messages may be a DoS attack * (excessive CPU consumption). */ if( ssl->nb_zero > 3 ) { SSL_DEBUG_MSG( 1, ( "received four consecutive empty " "messages, possible DoS attack" ) ); return( POLARSSL_ERR_SSL_INVALID_MAC ); } } else ssl->nb_zero = 0; /* Input counter not used with DTLS right now, * but it doesn't hurt to have this part ready */ for( i = 8; i > ssl_ep_len( ssl ); i-- ) if( ++ssl->in_ctr[i - 1] != 0 ) break; /* The loop goes to its end iff the counter is wrapping */ if( i == ssl_ep_len( ssl ) ) { SSL_DEBUG_MSG( 1, ( "incoming message counter would wrap" ) ); return( POLARSSL_ERR_SSL_COUNTER_WRAPPING ); } SSL_DEBUG_MSG( 2, ( "<= decrypt buf" ) ); return( 0 ); } #if defined(POLARSSL_ZLIB_SUPPORT) /* * Compression/decompression functions */ static int ssl_compress_buf( ssl_context *ssl ) { int ret; unsigned char *msg_post = ssl->out_msg; size_t len_pre = ssl->out_msglen; unsigned char *msg_pre = ssl->compress_buf; SSL_DEBUG_MSG( 2, ( "=> compress buf" ) ); if( len_pre == 0 ) return( 0 ); memcpy( msg_pre, ssl->out_msg, len_pre ); SSL_DEBUG_MSG( 3, ( "before compression: msglen = %d, ", ssl->out_msglen ) ); SSL_DEBUG_BUF( 4, "before compression: output payload", ssl->out_msg, ssl->out_msglen ); ssl->transform_out->ctx_deflate.next_in = msg_pre; ssl->transform_out->ctx_deflate.avail_in = len_pre; ssl->transform_out->ctx_deflate.next_out = msg_post; ssl->transform_out->ctx_deflate.avail_out = SSL_BUFFER_LEN; ret = deflate( &ssl->transform_out->ctx_deflate, Z_SYNC_FLUSH ); if( ret != Z_OK ) { SSL_DEBUG_MSG( 1, ( "failed to perform compression (%d)", ret ) ); return( POLARSSL_ERR_SSL_COMPRESSION_FAILED ); } ssl->out_msglen = SSL_BUFFER_LEN - ssl->transform_out->ctx_deflate.avail_out; SSL_DEBUG_MSG( 3, ( "after compression: msglen = %d, ", ssl->out_msglen ) ); SSL_DEBUG_BUF( 4, "after compression: output payload", ssl->out_msg, ssl->out_msglen ); SSL_DEBUG_MSG( 2, ( "<= compress buf" ) ); return( 0 ); } static int ssl_decompress_buf( ssl_context *ssl ) { int ret; unsigned char *msg_post = ssl->in_msg; size_t len_pre = ssl->in_msglen; unsigned char *msg_pre = ssl->compress_buf; SSL_DEBUG_MSG( 2, ( "=> decompress buf" ) ); if( len_pre == 0 ) return( 0 ); memcpy( msg_pre, ssl->in_msg, len_pre ); SSL_DEBUG_MSG( 3, ( "before decompression: msglen = %d, ", ssl->in_msglen ) ); SSL_DEBUG_BUF( 4, "before decompression: input payload", ssl->in_msg, ssl->in_msglen ); ssl->transform_in->ctx_inflate.next_in = msg_pre; ssl->transform_in->ctx_inflate.avail_in = len_pre; ssl->transform_in->ctx_inflate.next_out = msg_post; ssl->transform_in->ctx_inflate.avail_out = SSL_MAX_CONTENT_LEN; ret = inflate( &ssl->transform_in->ctx_inflate, Z_SYNC_FLUSH ); if( ret != Z_OK ) { SSL_DEBUG_MSG( 1, ( "failed to perform decompression (%d)", ret ) ); return( POLARSSL_ERR_SSL_COMPRESSION_FAILED ); } ssl->in_msglen = SSL_MAX_CONTENT_LEN - ssl->transform_in->ctx_inflate.avail_out; SSL_DEBUG_MSG( 3, ( "after decompression: msglen = %d, ", ssl->in_msglen ) ); SSL_DEBUG_BUF( 4, "after decompression: input payload", ssl->in_msg, ssl->in_msglen ); SSL_DEBUG_MSG( 2, ( "<= decompress buf" ) ); return( 0 ); } #endif /* POLARSSL_ZLIB_SUPPORT */ /* * Fill the input message buffer by appending data to it. * The amount of data already fetched is in ssl->in_left. * * If we return 0, is it guaranteed that (at least) nb_want bytes are * available (from this read and/or a previous one). Otherwise, an error code * is returned (possibly EOF or WANT_READ). * * With stream transport (TLS) on success ssl->in_left == nb_want, but * with datagram transport (DTLS) on success ssl->in_left >= nb_want, * since we always read a whole datagram at once. * * For DTLS, it is up to the caller to set ssl->next_record_offset when * they're done reading a record. */ int ssl_fetch_input( ssl_context *ssl, size_t nb_want ) { int ret; size_t len; SSL_DEBUG_MSG( 2, ( "=> fetch input" ) ); if( nb_want > SSL_BUFFER_LEN - (size_t)( ssl->in_hdr - ssl->in_buf ) ) { SSL_DEBUG_MSG( 1, ( "requesting more data than fits" ) ); return( POLARSSL_ERR_SSL_BAD_INPUT_DATA ); } #if defined(POLARSSL_SSL_PROTO_DTLS) if( ssl->transport == SSL_TRANSPORT_DATAGRAM ) { /* * The point is, we need to always read a full datagram at once, so we * sometimes read more then requested, and handle the additional data. * It could be the rest of the current record (while fetching the * header) and/or some other records in the same datagram. */ /* * Move to the next record in the already read datagram if applicable */ if( ssl->next_record_offset != 0 ) { if( ssl->in_left < ssl->next_record_offset ) { SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( POLARSSL_ERR_SSL_INTERNAL_ERROR ); } ssl->in_left -= ssl->next_record_offset; if( ssl->in_left != 0 ) { SSL_DEBUG_MSG( 2, ( "next record in same datagram, offset: %d", ssl->next_record_offset ) ); memmove( ssl->in_hdr, ssl->in_hdr + ssl->next_record_offset, ssl->in_left ); } ssl->next_record_offset = 0; } SSL_DEBUG_MSG( 2, ( "in_left: %d, nb_want: %d", ssl->in_left, nb_want ) ); /* * Done if we already have enough data. */ if( nb_want <= ssl->in_left) { SSL_DEBUG_MSG( 2, ( "<= fetch input" ) ); return( 0 ); } /* * A record can't be split accross datagrams. If we need to read but * are not at the beginning of a new record, the caller did something * wrong. */ if( ssl->in_left != 0 ) { SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( POLARSSL_ERR_SSL_INTERNAL_ERROR ); } len = SSL_BUFFER_LEN - ( ssl->in_hdr - ssl->in_buf ); ret = ssl->f_recv( ssl->p_recv, ssl->in_hdr, len ); SSL_DEBUG_RET( 2, "ssl->f_recv", ret ); if( ret == 0 ) return( POLARSSL_ERR_SSL_CONN_EOF ); if( ret < 0 ) return( ret ); ssl->in_left = ret; } else #endif { SSL_DEBUG_MSG( 2, ( "in_left: %d, nb_want: %d", ssl->in_left, nb_want ) ); while( ssl->in_left < nb_want ) { len = nb_want - ssl->in_left; ret = ssl->f_recv( ssl->p_recv, ssl->in_hdr + ssl->in_left, len ); SSL_DEBUG_MSG( 2, ( "in_left: %d, nb_want: %d", ssl->in_left, nb_want ) ); SSL_DEBUG_RET( 2, "ssl->f_recv", ret ); if( ret == 0 ) return( POLARSSL_ERR_SSL_CONN_EOF ); if( ret < 0 ) return( ret ); ssl->in_left += ret; } } SSL_DEBUG_MSG( 2, ( "<= fetch input" ) ); return( 0 ); } /* * Flush any data not yet written */ int ssl_flush_output( ssl_context *ssl ) { int ret; unsigned char *buf, i; SSL_DEBUG_MSG( 2, ( "=> flush output" ) ); /* Avoid incrementing counter if data is flushed */ if( ssl->out_left == 0 ) { SSL_DEBUG_MSG( 2, ( "<= flush output" ) ); return( 0 ); } while( ssl->out_left > 0 ) { SSL_DEBUG_MSG( 2, ( "message length: %d, out_left: %d", ssl_hdr_len( ssl ) + ssl->out_msglen, ssl->out_left ) ); buf = ssl->out_hdr + ssl_hdr_len( ssl ) + ssl->out_msglen - ssl->out_left; ret = ssl->f_send( ssl->p_send, buf, ssl->out_left ); SSL_DEBUG_RET( 2, "ssl->f_send", ret ); if( ret <= 0 ) return( ret ); ssl->out_left -= ret; } for( i = 8; i > ssl_ep_len( ssl ); i-- ) if( ++ssl->out_ctr[i - 1] != 0 ) break; /* The loop goes to its end iff the counter is wrapping */ if( i == ssl_ep_len( ssl ) ) { SSL_DEBUG_MSG( 1, ( "outgoing message counter would wrap" ) ); return( POLARSSL_ERR_SSL_COUNTER_WRAPPING ); } SSL_DEBUG_MSG( 2, ( "<= flush output" ) ); return( 0 ); } /* * Record layer functions */ int ssl_write_record( ssl_context *ssl ) { int ret, done = 0; size_t len = ssl->out_msglen; SSL_DEBUG_MSG( 2, ( "=> write record" ) ); if( ssl->out_msgtype == SSL_MSG_HANDSHAKE ) { ssl->out_msg[1] = (unsigned char)( ( len - 4 ) >> 16 ); ssl->out_msg[2] = (unsigned char)( ( len - 4 ) >> 8 ); ssl->out_msg[3] = (unsigned char)( ( len - 4 ) ); /* * DTLS has additional fields in the Handshake layer, * between the length field and the actual payload: * uint16 message_seq; * uint24 fragment_offset; * uint24 fragment_length; */ #if defined(POLARSSL_SSL_PROTO_DTLS) if( ssl->transport == SSL_TRANSPORT_DATAGRAM ) { /* Make room for the additional DTLS fields */ memmove( ssl->out_msg + 12, ssl->out_msg + 4, len - 4 ); ssl->out_msglen += 8; len += 8; /* Write message_seq and update it, except for HelloRequest */ if( ssl->out_msg[0] != SSL_HS_HELLO_REQUEST ) { ssl->out_msg[4] = ( ssl->handshake->out_msg_seq >> 8 ) & 0xFF; ssl->out_msg[5] = ( ssl->handshake->out_msg_seq ) & 0xFF; ++( ssl->handshake->out_msg_seq ); } else { ssl->out_msg[4] = 0; ssl->out_msg[5] = 0; } /* We don't fragment, so frag_offset = 0 and frag_len = len */ memset( ssl->out_msg + 6, 0x00, 3 ); memcpy( ssl->out_msg + 9, ssl->out_msg + 1, 3 ); } #endif /* POLARSSL_SSL_PROTO_DTLS */ if( ssl->out_msg[0] != SSL_HS_HELLO_REQUEST ) ssl->handshake->update_checksum( ssl, ssl->out_msg, len ); } #if defined(POLARSSL_ZLIB_SUPPORT) if( ssl->transform_out != NULL && ssl->session_out->compression == SSL_COMPRESS_DEFLATE ) { if( ( ret = ssl_compress_buf( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_compress_buf", ret ); return( ret ); } len = ssl->out_msglen; } #endif /*POLARSSL_ZLIB_SUPPORT */ #if defined(POLARSSL_SSL_HW_RECORD_ACCEL) if( ssl_hw_record_write != NULL ) { SSL_DEBUG_MSG( 2, ( "going for ssl_hw_record_write()" ) ); ret = ssl_hw_record_write( ssl ); if( ret != 0 && ret != POLARSSL_ERR_SSL_HW_ACCEL_FALLTHROUGH ) { SSL_DEBUG_RET( 1, "ssl_hw_record_write", ret ); return( POLARSSL_ERR_SSL_HW_ACCEL_FAILED ); } if( ret == 0 ) done = 1; } #endif /* POLARSSL_SSL_HW_RECORD_ACCEL */ if( !done ) { ssl->out_hdr[0] = (unsigned char) ssl->out_msgtype; ssl_write_version( ssl->major_ver, ssl->minor_ver, ssl->transport, ssl->out_hdr + 1 ); ssl->out_len[0] = (unsigned char)( len >> 8 ); ssl->out_len[1] = (unsigned char)( len ); if( ssl->transform_out != NULL ) { if( ( ret = ssl_encrypt_buf( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_encrypt_buf", ret ); return( ret ); } len = ssl->out_msglen; ssl->out_len[0] = (unsigned char)( len >> 8 ); ssl->out_len[1] = (unsigned char)( len ); } ssl->out_left = ssl_hdr_len( ssl ) + ssl->out_msglen; SSL_DEBUG_MSG( 3, ( "output record: msgtype = %d, " "version = [%d:%d], msglen = %d", ssl->out_hdr[0], ssl->out_hdr[1], ssl->out_hdr[2], ( ssl->out_len[0] << 8 ) | ssl->out_len[1] ) ); SSL_DEBUG_BUF( 4, "output record sent to network", ssl->out_hdr, ssl_hdr_len( ssl ) + ssl->out_msglen ); } if( ( ret = ssl_flush_output( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_flush_output", ret ); return( ret ); } SSL_DEBUG_MSG( 2, ( "<= write record" ) ); return( 0 ); } #if defined(POLARSSL_SSL_PROTO_DTLS) /* * Mark bits in bitmask (used for DTLS HS reassembly) */ static void ssl_bitmask_set( unsigned char *mask, size_t offset, size_t len ) { unsigned int start_bits, end_bits; start_bits = 8 - ( offset % 8 ); if( start_bits != 8 ) { size_t first_byte_idx = offset / 8; /* Special case */ if( len <= start_bits ) { for( ; len != 0; len-- ) mask[first_byte_idx] |= 1 << ( start_bits - len ); /* Avoid potential issues with offset or len becoming invalid */ return; } offset += start_bits; /* Now offset % 8 == 0 */ len -= start_bits; for( ; start_bits != 0; start_bits-- ) mask[first_byte_idx] |= 1 << ( start_bits - 1 ); } end_bits = len % 8; if( end_bits != 0 ) { size_t last_byte_idx = ( offset + len ) / 8; len -= end_bits; /* Now len % 8 == 0 */ for( ; end_bits != 0; end_bits-- ) mask[last_byte_idx] |= 1 << ( 8 - end_bits ); } memset( mask + offset / 8, 0xFF, len / 8 ); } /* * Check that bitmask is full */ static int ssl_bitmask_check( unsigned char *mask, size_t len ) { size_t i; for( i = 0; i < len / 8; i++ ) if( mask[i] != 0xFF ) return( -1 ); for( i = 0; i < len % 8; i++ ) if( ( mask[len / 8] & ( 1 << ( 7 - i ) ) ) == 0 ) return( -1 ); return( 0 ); } /* * Reassemble fragmented DTLS handshake messages. * * Use a temporary buffer for reassembly, divided in two parts: * - the first holds the reassembled message (including handshake header), * - the second holds a bitmask indicating which parts of the message * (excluding headers) have been received so far. */ static int ssl_reassemble_dtls_handshake( ssl_context *ssl ) { unsigned char *msg, *bitmask; size_t frag_len, frag_off; size_t msg_len = ssl->in_hslen - 12; /* Without headers */ if( ssl->handshake == NULL ) { SSL_DEBUG_MSG( 1, ( "not supported outside handshake (for now)" ) ); return( POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE ); } /* * For first fragment, check size and allocate buffer */ if( ssl->handshake->hs_msg == NULL ) { size_t alloc_len; SSL_DEBUG_MSG( 2, ( "initialize reassembly, total length = %d", msg_len ) ); if( ssl->in_hslen > SSL_MAX_CONTENT_LEN ) { SSL_DEBUG_MSG( 1, ( "handshake message too large" ) ); return( POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE ); } /* The bitmask needs one bit per byte of message excluding header */ alloc_len = 12 + msg_len + msg_len / 8 + ( msg_len % 8 != 0 ); ssl->handshake->hs_msg = polarssl_malloc( alloc_len ); if( ssl->handshake->hs_msg == NULL ) { SSL_DEBUG_MSG( 1, ( "malloc failed (%d bytes)", alloc_len ) ); return( POLARSSL_ERR_SSL_MALLOC_FAILED ); } memset( ssl->handshake->hs_msg, 0, alloc_len ); /* Prepare final header: copy msg_type, length and message_seq, * then add standardised fragment_offset and fragment_length */ memcpy( ssl->handshake->hs_msg, ssl->in_msg, 6 ); memset( ssl->handshake->hs_msg + 6, 0, 3 ); memcpy( ssl->handshake->hs_msg + 9, ssl->handshake->hs_msg + 1, 3 ); } else { /* Make sure msg_type and length are consistent */ if( memcmp( ssl->handshake->hs_msg, ssl->in_msg, 4 ) != 0 ) { SSL_DEBUG_MSG( 1, ( "fragment header mismatch" ) ); return( POLARSSL_ERR_SSL_INVALID_RECORD ); } } msg = ssl->handshake->hs_msg + 12; bitmask = msg + msg_len; /* * Check and copy current fragment */ frag_off = ( ssl->in_msg[6] << 16 ) | ( ssl->in_msg[7] << 8 ) | ssl->in_msg[8]; frag_len = ( ssl->in_msg[9] << 16 ) | ( ssl->in_msg[10] << 8 ) | ssl->in_msg[11]; if( frag_off + frag_len > msg_len ) { SSL_DEBUG_MSG( 1, ( "invalid fragment offset/len: %d + %d > %d", frag_off, frag_len, msg_len ) ); return( POLARSSL_ERR_SSL_INVALID_RECORD ); } if( frag_len + 12 > ssl->in_msglen ) { SSL_DEBUG_MSG( 1, ( "invalid fragment length: %d + 12 > %d", frag_len, ssl->in_msglen ) ); return( POLARSSL_ERR_SSL_INVALID_RECORD ); } SSL_DEBUG_MSG( 2, ( "adding fragment, offset = %d, length = %d", frag_off, frag_len ) ); memcpy( msg + frag_off, ssl->in_msg + 12, frag_len ); ssl_bitmask_set( bitmask, frag_off, frag_len ); /* * Do we have the complete message by now? * If yes, finalize it, else ask to read the next record. */ if( ssl_bitmask_check( bitmask, msg_len ) != 0 ) { SSL_DEBUG_MSG( 2, ( "message is not complete yet" ) ); return( POLARSSL_ERR_NET_WANT_READ ); } SSL_DEBUG_MSG( 2, ( "handshake message completed" ) ); if( ssl->in_left > ssl->next_record_offset ) { /* * We've got more data in the buffer after the current record, * that we don't want to overwrite. Move it before writing the * reassembled message, and adjust in_left and next_record_offset. */ unsigned char *cur_remain = ssl->in_hdr + ssl->next_record_offset; unsigned char *new_remain = ssl->in_msg + ssl->in_hslen; size_t remain_len = ssl->in_left - ssl->next_record_offset; /* First compute and check new lengths */ ssl->next_record_offset = new_remain - ssl->in_hdr; ssl->in_left = ssl->next_record_offset + remain_len; if( ssl->in_left > SSL_BUFFER_LEN - (size_t)( ssl->in_hdr - ssl->in_buf ) ) { SSL_DEBUG_MSG( 1, ( "reassembled message too large for buffer" ) ); return( POLARSSL_ERR_SSL_BUFFER_TOO_SMALL ); } memmove( new_remain, cur_remain, remain_len ); } memcpy( ssl->in_msg, ssl->handshake->hs_msg, ssl->in_hslen ); polarssl_free( ssl->handshake->hs_msg ); ssl->handshake->hs_msg = NULL; SSL_DEBUG_BUF( 3, "reassembled handshake message", ssl->in_msg, ssl->in_hslen ); return( 0 ); } #endif /* POLARSSL_SSL_PROTO_DTLS */ static int ssl_prepare_handshake_record( ssl_context *ssl ) { if( ssl->in_msglen < ssl_hs_hdr_len( ssl ) ) { SSL_DEBUG_MSG( 1, ( "handshake message too short: %d", ssl->in_msglen ) ); return( POLARSSL_ERR_SSL_INVALID_RECORD ); } ssl->in_hslen = ssl_hs_hdr_len( ssl ) + ( ( ssl->in_msg[1] << 16 ) | ( ssl->in_msg[2] << 8 ) | ssl->in_msg[3] ); SSL_DEBUG_MSG( 3, ( "handshake message: msglen =" " %d, type = %d, hslen = %d", ssl->in_msglen, ssl->in_msg[0], ssl->in_hslen ) ); #if defined(POLARSSL_SSL_PROTO_DTLS) if( ssl->transport == SSL_TRANSPORT_DATAGRAM ) { int ret; unsigned int recv_msg_seq = ( ssl->in_msg[4] << 8 ) | ssl->in_msg[5]; /* ssl->handshake is NULL when receiving ClientHello for renego */ if( ssl->handshake != NULL && recv_msg_seq != ssl->handshake->in_msg_seq ) { SSL_DEBUG_MSG( 2, ( "dropping out-of-order message: " "message_seq = %d, expected = %d", recv_msg_seq, ssl->handshake->in_msg_seq ) ); return( POLARSSL_ERR_NET_WANT_READ ); } /* Wait until message completion to increment in_msg_seq */ /* Reassemble if current message is fragmented or reassembly is * already in progress */ if( ssl->in_msglen < ssl->in_hslen || memcmp( ssl->in_msg + 6, "\0\0\0", 3 ) != 0 || memcmp( ssl->in_msg + 9, ssl->in_msg + 1, 3 ) != 0 || ( ssl->handshake != NULL && ssl->handshake->hs_msg != NULL ) ) { SSL_DEBUG_MSG( 2, ( "found fragmented DTLS handshake message" ) ); if( ( ret = ssl_reassemble_dtls_handshake( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_reassemble_dtls_handshake", ret ); return( ret ); } } } else #endif /* POLARSSL_SSL_PROTO_DTLS */ /* With TLS we don't handle fragmentation (for now) */ if( ssl->in_msglen < ssl->in_hslen ) { SSL_DEBUG_MSG( 1, ( "TLS handshake fragmentation not supported" ) ); return( POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE ); } if( ssl->state != SSL_HANDSHAKE_OVER ) ssl->handshake->update_checksum( ssl, ssl->in_msg, ssl->in_hslen ); /* Handshake message is complete, increment counter */ #if defined(POLARSSL_SSL_PROTO_DTLS) if( ssl->transport == SSL_TRANSPORT_DATAGRAM && ssl->handshake != NULL ) { ssl->handshake->in_msg_seq++; } #endif /* * For DTLS, we move data so that is looks like TLS handshake format to * other functions. * Except on server after the initial handshake (wait until after * update_checksum() in ssl_parse_client_hello()). */ #if defined(POLARSSL_SSL_PROTO_DTLS) if( ssl->transport == SSL_TRANSPORT_DATAGRAM && ! ( ssl->endpoint == SSL_IS_SERVER && ssl->state == SSL_HANDSHAKE_OVER ) ) { memmove( ssl->in_msg + 4, ssl->in_msg + 12, ssl->in_hslen - 12 ); ssl->in_hslen -= 8; } #endif /* POLARSSL_SSL_PROTO_DTLS */ return( 0 ); } /* * ContentType type; * ProtocolVersion version; * uint16 epoch; // DTLS only * uint48 sequence_number; // DTLS only * uint16 length; */ static int ssl_parse_record_header( ssl_context *ssl ) { int ret; int major_ver, minor_ver; SSL_DEBUG_BUF( 4, "input record header", ssl->in_hdr, ssl_hdr_len( ssl ) ); ssl->in_msgtype = ssl->in_hdr[0]; ssl->in_msglen = ( ssl->in_len[0] << 8 ) | ssl->in_len[1]; ssl_read_version( &major_ver, &minor_ver, ssl->transport, ssl->in_hdr + 1 ); SSL_DEBUG_MSG( 3, ( "input record: msgtype = %d, " "version = [%d:%d], msglen = %d", ssl->in_msgtype, major_ver, minor_ver, ssl->in_msglen ) ); /* Check record type */ if( ssl->in_msgtype != SSL_MSG_HANDSHAKE && ssl->in_msgtype != SSL_MSG_ALERT && ssl->in_msgtype != SSL_MSG_CHANGE_CIPHER_SPEC && ssl->in_msgtype != SSL_MSG_APPLICATION_DATA ) { SSL_DEBUG_MSG( 1, ( "unknown record type" ) ); if( ( ret = ssl_send_alert_message( ssl, SSL_ALERT_LEVEL_FATAL, SSL_ALERT_MSG_UNEXPECTED_MESSAGE ) ) != 0 ) { return( ret ); } return( POLARSSL_ERR_SSL_INVALID_RECORD ); } /* Check version */ if( major_ver != ssl->major_ver ) { SSL_DEBUG_MSG( 1, ( "major version mismatch" ) ); return( POLARSSL_ERR_SSL_INVALID_RECORD ); } if( minor_ver > ssl->max_minor_ver ) { SSL_DEBUG_MSG( 1, ( "minor version mismatch" ) ); return( POLARSSL_ERR_SSL_INVALID_RECORD ); } /* Check epoch with DTLS */ #if defined(POLARSSL_SSL_PROTO_DTLS) if( ssl->transport == SSL_TRANSPORT_DATAGRAM ) { unsigned int exp_epoch = ( ssl->in_ctr[0] << 8 ) | ssl->in_ctr[1]; unsigned int rec_epoch = ( ssl->in_hdr[3] << 8 ) | ssl->in_hdr[4]; if( exp_epoch != rec_epoch ) { SSL_DEBUG_MSG( 1, ( "discarding record from another epoch: " "expected %d, received %d", exp_epoch, rec_epoch ) ); return( POLARSSL_ERR_NET_WANT_READ ); } } #endif /* Check length against the size of our buffer */ if( ssl->in_msglen > SSL_BUFFER_LEN - (size_t)( ssl->in_msg - ssl->in_buf ) ) { SSL_DEBUG_MSG( 1, ( "bad message length" ) ); return( POLARSSL_ERR_SSL_INVALID_RECORD ); } /* Check length against bounds of the current transform and version */ if( ssl->transform_in == NULL ) { if( ssl->in_msglen < 1 || ssl->in_msglen > SSL_MAX_CONTENT_LEN ) { SSL_DEBUG_MSG( 1, ( "bad message length" ) ); return( POLARSSL_ERR_SSL_INVALID_RECORD ); } } else { if( ssl->in_msglen < ssl->transform_in->minlen ) { SSL_DEBUG_MSG( 1, ( "bad message length" ) ); return( POLARSSL_ERR_SSL_INVALID_RECORD ); } #if defined(POLARSSL_SSL_PROTO_SSL3) if( ssl->minor_ver == SSL_MINOR_VERSION_0 && ssl->in_msglen > ssl->transform_in->minlen + SSL_MAX_CONTENT_LEN ) { SSL_DEBUG_MSG( 1, ( "bad message length" ) ); return( POLARSSL_ERR_SSL_INVALID_RECORD ); } #endif #if defined(POLARSSL_SSL_PROTO_TLS1) || defined(POLARSSL_SSL_PROTO_TLS1_1) || \ defined(POLARSSL_SSL_PROTO_TLS1_2) /* * TLS encrypted messages can have up to 256 bytes of padding */ if( ssl->minor_ver >= SSL_MINOR_VERSION_1 && ssl->in_msglen > ssl->transform_in->minlen + SSL_MAX_CONTENT_LEN + 256 ) { SSL_DEBUG_MSG( 1, ( "bad message length" ) ); return( POLARSSL_ERR_SSL_INVALID_RECORD ); } #endif } return( 0 ); } /* * If applicable, decrypt (and decompress) record content */ static int ssl_prepare_record_content( ssl_context *ssl ) { int ret, done = 0; SSL_DEBUG_BUF( 4, "input record from network", ssl->in_hdr, ssl_hdr_len( ssl ) + ssl->in_msglen ); #if defined(POLARSSL_SSL_HW_RECORD_ACCEL) if( ssl_hw_record_read != NULL ) { SSL_DEBUG_MSG( 2, ( "going for ssl_hw_record_read()" ) ); ret = ssl_hw_record_read( ssl ); if( ret != 0 && ret != POLARSSL_ERR_SSL_HW_ACCEL_FALLTHROUGH ) { SSL_DEBUG_RET( 1, "ssl_hw_record_read", ret ); return( POLARSSL_ERR_SSL_HW_ACCEL_FAILED ); } if( ret == 0 ) done = 1; } #endif /* POLARSSL_SSL_HW_RECORD_ACCEL */ if( !done && ssl->transform_in != NULL ) { if( ( ret = ssl_decrypt_buf( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_decrypt_buf", ret ); return( ret ); } SSL_DEBUG_BUF( 4, "input payload after decrypt", ssl->in_msg, ssl->in_msglen ); if( ssl->in_msglen > SSL_MAX_CONTENT_LEN ) { SSL_DEBUG_MSG( 1, ( "bad message length" ) ); return( POLARSSL_ERR_SSL_INVALID_RECORD ); } } #if defined(POLARSSL_ZLIB_SUPPORT) if( ssl->transform_in != NULL && ssl->session_in->compression == SSL_COMPRESS_DEFLATE ) { if( ( ret = ssl_decompress_buf( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_decompress_buf", ret ); return( ret ); } // TODO: what's the purpose of these lines? is in_len used? ssl->in_len[0] = (unsigned char)( ssl->in_msglen >> 8 ); ssl->in_len[1] = (unsigned char)( ssl->in_msglen ); } #endif /* POLARSSL_ZLIB_SUPPORT */ return( 0 ); } /* * Read a record. * * For DTLS, silently ignore invalid records (RFC 4.1.2.7.) * and continue reading until a valid record is found. */ int ssl_read_record( ssl_context *ssl ) { int ret; SSL_DEBUG_MSG( 2, ( "=> read record" ) ); /* * With DTLS, we cheated on in_hslen to make the handshake message look * like TLS format, restore the truth now */ #if defined(POLARSSL_SSL_PROTO_DTLS) if( ssl->in_hslen != 0 && ssl->transport == SSL_TRANSPORT_DATAGRAM ) ssl->in_hslen += 8; #endif if( ssl->in_hslen != 0 && ssl->in_hslen < ssl->in_msglen ) { /* * Get next Handshake message in the current record */ ssl->in_msglen -= ssl->in_hslen; memmove( ssl->in_msg, ssl->in_msg + ssl->in_hslen, ssl->in_msglen ); SSL_DEBUG_BUF( 4, "remaining content in record", ssl->in_msg, ssl->in_msglen ); if( ( ret = ssl_prepare_handshake_record( ssl ) ) != 0 ) return( ret ); return( 0 ); } ssl->in_hslen = 0; /* * Read the record header and parse it */ #if defined(POLARSSL_SSL_PROTO_DTLS) read_record_header: #endif if( ( ret = ssl_fetch_input( ssl, ssl_hdr_len( ssl ) ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_fetch_input", ret ); return( ret ); } if( ( ret = ssl_parse_record_header( ssl ) ) != 0 ) { #if defined(POLARSSL_SSL_PROTO_DTLS) if( ssl->transport == SSL_TRANSPORT_DATAGRAM ) { /* Ignore bad record and get next one; drop the whole datagram * since current header cannot be trusted to find the next record * in current datagram */ ssl->next_record_offset = 0; ssl->in_left = 0; SSL_DEBUG_MSG( 2, ( "discarding invalid record" ) ); goto read_record_header; } #endif return( ret ); } /* * Read and optionally decrypt the message contents */ if( ( ret = ssl_fetch_input( ssl, ssl_hdr_len( ssl ) + ssl->in_msglen ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_fetch_input", ret ); return( ret ); } /* Done reading this record, get ready for the next one */ #if defined(POLARSSL_SSL_PROTO_DTLS) if( ssl->transport == SSL_TRANSPORT_DATAGRAM ) ssl->next_record_offset = ssl->in_msglen + ssl_hdr_len( ssl ); else #endif ssl->in_left = 0; if( ( ret = ssl_prepare_record_content( ssl ) ) != 0 ) { #if defined(POLARSSL_SSL_PROTO_DTLS) if( ssl->transport == SSL_TRANSPORT_DATAGRAM ) { /* Silently discard invalid records */ if( ret == POLARSSL_ERR_SSL_INVALID_RECORD || ret == POLARSSL_ERR_SSL_INVALID_MAC ) { SSL_DEBUG_MSG( 2, ( "discarding invalid record" ) ); goto read_record_header; } return( ret ); } else #endif { /* Error out (and send alert) on invalid records */ #if defined(POLARSSL_SSL_ALERT_MESSAGES) if( ret == POLARSSL_ERR_SSL_INVALID_MAC ) { ssl_send_alert_message( ssl, SSL_ALERT_LEVEL_FATAL, SSL_ALERT_MSG_BAD_RECORD_MAC ); } #endif return( ret ); } } /* * Handle particular types of records */ if( ssl->in_msgtype == SSL_MSG_HANDSHAKE ) { if( ( ret = ssl_prepare_handshake_record( ssl ) ) != 0 ) return( ret ); } if( ssl->in_msgtype == SSL_MSG_ALERT ) { SSL_DEBUG_MSG( 2, ( "got an alert message, type: [%d:%d]", ssl->in_msg[0], ssl->in_msg[1] ) ); /* * Ignore non-fatal alerts, except close_notify */ if( ssl->in_msg[0] == SSL_ALERT_LEVEL_FATAL ) { SSL_DEBUG_MSG( 1, ( "is a fatal alert message (msg %d)", ssl->in_msg[1] ) ); return( POLARSSL_ERR_SSL_FATAL_ALERT_MESSAGE ); } if( ssl->in_msg[0] == SSL_ALERT_LEVEL_WARNING && ssl->in_msg[1] == SSL_ALERT_MSG_CLOSE_NOTIFY ) { SSL_DEBUG_MSG( 2, ( "is a close notify message" ) ); return( POLARSSL_ERR_SSL_PEER_CLOSE_NOTIFY ); } } SSL_DEBUG_MSG( 2, ( "<= read record" ) ); return( 0 ); } int ssl_send_fatal_handshake_failure( ssl_context *ssl ) { int ret; if( ( ret = ssl_send_alert_message( ssl, SSL_ALERT_LEVEL_FATAL, SSL_ALERT_MSG_HANDSHAKE_FAILURE ) ) != 0 ) { return( ret ); } return( 0 ); } int ssl_send_alert_message( ssl_context *ssl, unsigned char level, unsigned char message ) { int ret; SSL_DEBUG_MSG( 2, ( "=> send alert message" ) ); ssl->out_msgtype = SSL_MSG_ALERT; ssl->out_msglen = 2; ssl->out_msg[0] = level; ssl->out_msg[1] = message; if( ( ret = ssl_write_record( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_write_record", ret ); return( ret ); } SSL_DEBUG_MSG( 2, ( "<= send alert message" ) ); return( 0 ); } /* * Handshake functions */ #if !defined(POLARSSL_KEY_EXCHANGE_RSA_ENABLED) && \ !defined(POLARSSL_KEY_EXCHANGE_RSA_PSK_ENABLED) && \ !defined(POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED) && \ !defined(POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED) && \ !defined(POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) && \ !defined(POLARSSL_KEY_EXCHANGE_ECDH_RSA_ENABLED) && \ !defined(POLARSSL_KEY_EXCHANGE_ECDH_ECDSA_ENABLED) int ssl_write_certificate( ssl_context *ssl ) { const ssl_ciphersuite_t *ciphersuite_info = ssl->transform_negotiate->ciphersuite_info; SSL_DEBUG_MSG( 2, ( "=> write certificate" ) ); if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_PSK || ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_PSK || ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_PSK ) { SSL_DEBUG_MSG( 2, ( "<= skip write certificate" ) ); ssl->state++; return( 0 ); } SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( POLARSSL_ERR_SSL_INTERNAL_ERROR ); } int ssl_parse_certificate( ssl_context *ssl ) { const ssl_ciphersuite_t *ciphersuite_info = ssl->transform_negotiate->ciphersuite_info; SSL_DEBUG_MSG( 2, ( "=> parse certificate" ) ); if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_PSK || ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_PSK || ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_PSK ) { SSL_DEBUG_MSG( 2, ( "<= skip parse certificate" ) ); ssl->state++; return( 0 ); } SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( POLARSSL_ERR_SSL_INTERNAL_ERROR ); } #else int ssl_write_certificate( ssl_context *ssl ) { int ret = POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE; size_t i, n; const x509_crt *crt; const ssl_ciphersuite_t *ciphersuite_info = ssl->transform_negotiate->ciphersuite_info; SSL_DEBUG_MSG( 2, ( "=> write certificate" ) ); if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_PSK || ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_PSK || ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_PSK ) { SSL_DEBUG_MSG( 2, ( "<= skip write certificate" ) ); ssl->state++; return( 0 ); } if( ssl->endpoint == SSL_IS_CLIENT ) { if( ssl->client_auth == 0 ) { SSL_DEBUG_MSG( 2, ( "<= skip write certificate" ) ); ssl->state++; return( 0 ); } #if defined(POLARSSL_SSL_PROTO_SSL3) /* * If using SSLv3 and got no cert, send an Alert message * (otherwise an empty Certificate message will be sent). */ if( ssl_own_cert( ssl ) == NULL && ssl->minor_ver == SSL_MINOR_VERSION_0 ) { ssl->out_msglen = 2; ssl->out_msgtype = SSL_MSG_ALERT; ssl->out_msg[0] = SSL_ALERT_LEVEL_WARNING; ssl->out_msg[1] = SSL_ALERT_MSG_NO_CERT; SSL_DEBUG_MSG( 2, ( "got no certificate to send" ) ); goto write_msg; } #endif /* POLARSSL_SSL_PROTO_SSL3 */ } else /* SSL_IS_SERVER */ { if( ssl_own_cert( ssl ) == NULL ) { SSL_DEBUG_MSG( 1, ( "got no certificate to send" ) ); return( POLARSSL_ERR_SSL_CERTIFICATE_REQUIRED ); } } SSL_DEBUG_CRT( 3, "own certificate", ssl_own_cert( ssl ) ); /* * 0 . 0 handshake type * 1 . 3 handshake length * 4 . 6 length of all certs * 7 . 9 length of cert. 1 * 10 . n-1 peer certificate * n . n+2 length of cert. 2 * n+3 . ... upper level cert, etc. */ i = 7; crt = ssl_own_cert( ssl ); while( crt != NULL ) { n = crt->raw.len; if( n > SSL_MAX_CONTENT_LEN - 3 - i ) { SSL_DEBUG_MSG( 1, ( "certificate too large, %d > %d", i + 3 + n, SSL_MAX_CONTENT_LEN ) ); return( POLARSSL_ERR_SSL_CERTIFICATE_TOO_LARGE ); } ssl->out_msg[i ] = (unsigned char)( n >> 16 ); ssl->out_msg[i + 1] = (unsigned char)( n >> 8 ); ssl->out_msg[i + 2] = (unsigned char)( n ); i += 3; memcpy( ssl->out_msg + i, crt->raw.p, n ); i += n; crt = crt->next; } ssl->out_msg[4] = (unsigned char)( ( i - 7 ) >> 16 ); ssl->out_msg[5] = (unsigned char)( ( i - 7 ) >> 8 ); ssl->out_msg[6] = (unsigned char)( ( i - 7 ) ); ssl->out_msglen = i; ssl->out_msgtype = SSL_MSG_HANDSHAKE; ssl->out_msg[0] = SSL_HS_CERTIFICATE; #if defined(POLARSSL_SSL_PROTO_SSL3) write_msg: #endif ssl->state++; if( ( ret = ssl_write_record( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_write_record", ret ); return( ret ); } SSL_DEBUG_MSG( 2, ( "<= write certificate" ) ); return( ret ); } int ssl_parse_certificate( ssl_context *ssl ) { int ret = POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE; size_t i, n; const ssl_ciphersuite_t *ciphersuite_info = ssl->transform_negotiate->ciphersuite_info; SSL_DEBUG_MSG( 2, ( "=> parse certificate" ) ); if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_PSK || ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_PSK || ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_PSK ) { SSL_DEBUG_MSG( 2, ( "<= skip parse certificate" ) ); ssl->state++; return( 0 ); } if( ssl->endpoint == SSL_IS_SERVER && ( ssl->authmode == SSL_VERIFY_NONE || ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_RSA_PSK ) ) { ssl->session_negotiate->verify_result = BADCERT_SKIP_VERIFY; SSL_DEBUG_MSG( 2, ( "<= skip parse certificate" ) ); ssl->state++; return( 0 ); } if( ( ret = ssl_read_record( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_read_record", ret ); return( ret ); } ssl->state++; #if defined(POLARSSL_SSL_PROTO_SSL3) /* * Check if the client sent an empty certificate */ if( ssl->endpoint == SSL_IS_SERVER && ssl->minor_ver == SSL_MINOR_VERSION_0 ) { if( ssl->in_msglen == 2 && ssl->in_msgtype == SSL_MSG_ALERT && ssl->in_msg[0] == SSL_ALERT_LEVEL_WARNING && ssl->in_msg[1] == SSL_ALERT_MSG_NO_CERT ) { SSL_DEBUG_MSG( 1, ( "SSLv3 client has no certificate" ) ); ssl->session_negotiate->verify_result = BADCERT_MISSING; if( ssl->authmode == SSL_VERIFY_OPTIONAL ) return( 0 ); else return( POLARSSL_ERR_SSL_NO_CLIENT_CERTIFICATE ); } } #endif /* POLARSSL_SSL_PROTO_SSL3 */ #if defined(POLARSSL_SSL_PROTO_TLS1) || defined(POLARSSL_SSL_PROTO_TLS1_1) || \ defined(POLARSSL_SSL_PROTO_TLS1_2) if( ssl->endpoint == SSL_IS_SERVER && ssl->minor_ver != SSL_MINOR_VERSION_0 ) { if( ssl->in_hslen == 7 && ssl->in_msgtype == SSL_MSG_HANDSHAKE && ssl->in_msg[0] == SSL_HS_CERTIFICATE && memcmp( ssl->in_msg + 4, "\0\0\0", 3 ) == 0 ) { SSL_DEBUG_MSG( 1, ( "TLSv1 client has no certificate" ) ); ssl->session_negotiate->verify_result = BADCERT_MISSING; if( ssl->authmode == SSL_VERIFY_REQUIRED ) return( POLARSSL_ERR_SSL_NO_CLIENT_CERTIFICATE ); else return( 0 ); } } #endif /* POLARSSL_SSL_PROTO_TLS1 || POLARSSL_SSL_PROTO_TLS1_1 || \ POLARSSL_SSL_PROTO_TLS1_2 */ if( ssl->in_msgtype != SSL_MSG_HANDSHAKE ) { SSL_DEBUG_MSG( 1, ( "bad certificate message" ) ); return( POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE ); } if( ssl->in_msg[0] != SSL_HS_CERTIFICATE || ssl->in_hslen < 10 ) { SSL_DEBUG_MSG( 1, ( "bad certificate message" ) ); return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE ); } /* * Same message structure as in ssl_write_certificate() */ n = ( ssl->in_msg[5] << 8 ) | ssl->in_msg[6]; if( ssl->in_msg[4] != 0 || ssl->in_hslen != 7 + n ) { SSL_DEBUG_MSG( 1, ( "bad certificate message" ) ); return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE ); } /* In case we tried to reuse a session but it failed */ if( ssl->session_negotiate->peer_cert != NULL ) { x509_crt_free( ssl->session_negotiate->peer_cert ); polarssl_free( ssl->session_negotiate->peer_cert ); } if( ( ssl->session_negotiate->peer_cert = (x509_crt *) polarssl_malloc( sizeof( x509_crt ) ) ) == NULL ) { SSL_DEBUG_MSG( 1, ( "malloc(%d bytes) failed", sizeof( x509_crt ) ) ); return( POLARSSL_ERR_SSL_MALLOC_FAILED ); } x509_crt_init( ssl->session_negotiate->peer_cert ); i = 7; while( i < ssl->in_hslen ) { if( ssl->in_msg[i] != 0 ) { SSL_DEBUG_MSG( 1, ( "bad certificate message" ) ); return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE ); } n = ( (unsigned int) ssl->in_msg[i + 1] << 8 ) | (unsigned int) ssl->in_msg[i + 2]; i += 3; if( n < 128 || i + n > ssl->in_hslen ) { SSL_DEBUG_MSG( 1, ( "bad certificate message" ) ); return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE ); } ret = x509_crt_parse_der( ssl->session_negotiate->peer_cert, ssl->in_msg + i, n ); if( ret != 0 ) { SSL_DEBUG_RET( 1, " x509_crt_parse_der", ret ); return( ret ); } i += n; } SSL_DEBUG_CRT( 3, "peer certificate", ssl->session_negotiate->peer_cert ); /* * On client, make sure the server cert doesn't change during renego to * avoid "triple handshake" attack: https://secure-resumption.com/ */ if( ssl->endpoint == SSL_IS_CLIENT && ssl->renegotiation == SSL_RENEGOTIATION ) { if( ssl->session->peer_cert == NULL ) { SSL_DEBUG_MSG( 1, ( "new server cert during renegotiation" ) ); return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE ); } if( ssl->session->peer_cert->raw.len != ssl->session_negotiate->peer_cert->raw.len || memcmp( ssl->session->peer_cert->raw.p, ssl->session_negotiate->peer_cert->raw.p, ssl->session->peer_cert->raw.len ) != 0 ) { SSL_DEBUG_MSG( 1, ( "server cert changed during renegotiation" ) ); return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE ); } } if( ssl->authmode != SSL_VERIFY_NONE ) { if( ssl->ca_chain == NULL ) { SSL_DEBUG_MSG( 1, ( "got no CA chain" ) ); return( POLARSSL_ERR_SSL_CA_CHAIN_REQUIRED ); } /* * Main check: verify certificate */ ret = x509_crt_verify( ssl->session_negotiate->peer_cert, ssl->ca_chain, ssl->ca_crl, ssl->peer_cn, &ssl->session_negotiate->verify_result, ssl->f_vrfy, ssl->p_vrfy ); if( ret != 0 ) { SSL_DEBUG_RET( 1, "x509_verify_cert", ret ); } /* * Secondary checks: always done, but change 'ret' only if it was 0 */ #if defined(POLARSSL_SSL_SET_CURVES) { pk_context *pk = &ssl->session_negotiate->peer_cert->pk; /* If certificate uses an EC key, make sure the curve is OK */ if( pk_can_do( pk, POLARSSL_PK_ECKEY ) && ! ssl_curve_is_acceptable( ssl, pk_ec( *pk )->grp.id ) ) { SSL_DEBUG_MSG( 1, ( "bad certificate (EC key curve)" ) ); if( ret == 0 ) ret = POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE; } } #endif /* POLARSSL_SSL_SET_CURVES */ if( ssl_check_cert_usage( ssl->session_negotiate->peer_cert, ciphersuite_info, ! ssl->endpoint ) != 0 ) { SSL_DEBUG_MSG( 1, ( "bad certificate (usage extensions)" ) ); if( ret == 0 ) ret = POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE; } if( ssl->authmode != SSL_VERIFY_REQUIRED ) ret = 0; } SSL_DEBUG_MSG( 2, ( "<= parse certificate" ) ); return( ret ); } #endif /* !POLARSSL_KEY_EXCHANGE_RSA_ENABLED !POLARSSL_KEY_EXCHANGE_RSA_PSK_ENABLED !POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED !POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED !POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED !POLARSSL_KEY_EXCHANGE_ECDH_RSA_ENABLED !POLARSSL_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */ int ssl_write_change_cipher_spec( ssl_context *ssl ) { int ret; SSL_DEBUG_MSG( 2, ( "=> write change cipher spec" ) ); ssl->out_msgtype = SSL_MSG_CHANGE_CIPHER_SPEC; ssl->out_msglen = 1; ssl->out_msg[0] = 1; ssl->state++; if( ( ret = ssl_write_record( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_write_record", ret ); return( ret ); } SSL_DEBUG_MSG( 2, ( "<= write change cipher spec" ) ); return( 0 ); } int ssl_parse_change_cipher_spec( ssl_context *ssl ) { int ret; SSL_DEBUG_MSG( 2, ( "=> parse change cipher spec" ) ); if( ( ret = ssl_read_record( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_read_record", ret ); return( ret ); } if( ssl->in_msgtype != SSL_MSG_CHANGE_CIPHER_SPEC ) { SSL_DEBUG_MSG( 1, ( "bad change cipher spec message" ) ); return( POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE ); } if( ssl->in_msglen != 1 || ssl->in_msg[0] != 1 ) { SSL_DEBUG_MSG( 1, ( "bad change cipher spec message" ) ); return( POLARSSL_ERR_SSL_BAD_HS_CHANGE_CIPHER_SPEC ); } ssl->state++; SSL_DEBUG_MSG( 2, ( "<= parse change cipher spec" ) ); return( 0 ); } void ssl_optimize_checksum( ssl_context *ssl, const ssl_ciphersuite_t *ciphersuite_info ) { ((void) ciphersuite_info); #if defined(POLARSSL_SSL_PROTO_SSL3) || defined(POLARSSL_SSL_PROTO_TLS1) || \ defined(POLARSSL_SSL_PROTO_TLS1_1) if( ssl->minor_ver < SSL_MINOR_VERSION_3 ) ssl->handshake->update_checksum = ssl_update_checksum_md5sha1; else #endif #if defined(POLARSSL_SSL_PROTO_TLS1_2) #if defined(POLARSSL_SHA512_C) if( ciphersuite_info->mac == POLARSSL_MD_SHA384 ) ssl->handshake->update_checksum = ssl_update_checksum_sha384; else #endif #if defined(POLARSSL_SHA256_C) if( ciphersuite_info->mac != POLARSSL_MD_SHA384 ) ssl->handshake->update_checksum = ssl_update_checksum_sha256; else #endif #endif /* POLARSSL_SSL_PROTO_TLS1_2 */ { SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return; } } void ssl_reset_checksum( ssl_context *ssl ) { #if defined(POLARSSL_SSL_PROTO_SSL3) || defined(POLARSSL_SSL_PROTO_TLS1) || \ defined(POLARSSL_SSL_PROTO_TLS1_1) md5_starts( &ssl->handshake->fin_md5 ); sha1_starts( &ssl->handshake->fin_sha1 ); #endif #if defined(POLARSSL_SSL_PROTO_TLS1_2) #if defined(POLARSSL_SHA256_C) sha256_starts( &ssl->handshake->fin_sha256, 0 ); #endif #if defined(POLARSSL_SHA512_C) sha512_starts( &ssl->handshake->fin_sha512, 1 ); #endif #endif /* POLARSSL_SSL_PROTO_TLS1_2 */ } static void ssl_update_checksum_start( ssl_context *ssl, const unsigned char *buf, size_t len ) { #if defined(POLARSSL_SSL_PROTO_SSL3) || defined(POLARSSL_SSL_PROTO_TLS1) || \ defined(POLARSSL_SSL_PROTO_TLS1_1) md5_update( &ssl->handshake->fin_md5 , buf, len ); sha1_update( &ssl->handshake->fin_sha1, buf, len ); #endif #if defined(POLARSSL_SSL_PROTO_TLS1_2) #if defined(POLARSSL_SHA256_C) sha256_update( &ssl->handshake->fin_sha256, buf, len ); #endif #if defined(POLARSSL_SHA512_C) sha512_update( &ssl->handshake->fin_sha512, buf, len ); #endif #endif /* POLARSSL_SSL_PROTO_TLS1_2 */ } #if defined(POLARSSL_SSL_PROTO_SSL3) || defined(POLARSSL_SSL_PROTO_TLS1) || \ defined(POLARSSL_SSL_PROTO_TLS1_1) static void ssl_update_checksum_md5sha1( ssl_context *ssl, const unsigned char *buf, size_t len ) { md5_update( &ssl->handshake->fin_md5 , buf, len ); sha1_update( &ssl->handshake->fin_sha1, buf, len ); } #endif #if defined(POLARSSL_SSL_PROTO_TLS1_2) #if defined(POLARSSL_SHA256_C) static void ssl_update_checksum_sha256( ssl_context *ssl, const unsigned char *buf, size_t len ) { sha256_update( &ssl->handshake->fin_sha256, buf, len ); } #endif #if defined(POLARSSL_SHA512_C) static void ssl_update_checksum_sha384( ssl_context *ssl, const unsigned char *buf, size_t len ) { sha512_update( &ssl->handshake->fin_sha512, buf, len ); } #endif #endif /* POLARSSL_SSL_PROTO_TLS1_2 */ #if defined(POLARSSL_SSL_PROTO_SSL3) static void ssl_calc_finished_ssl( ssl_context *ssl, unsigned char *buf, int from ) { const char *sender; md5_context md5; sha1_context sha1; unsigned char padbuf[48]; unsigned char md5sum[16]; unsigned char sha1sum[20]; ssl_session *session = ssl->session_negotiate; if( !session ) session = ssl->session; SSL_DEBUG_MSG( 2, ( "=> calc finished ssl" ) ); memcpy( &md5 , &ssl->handshake->fin_md5 , sizeof(md5_context) ); memcpy( &sha1, &ssl->handshake->fin_sha1, sizeof(sha1_context) ); /* * SSLv3: * hash = * MD5( master + pad2 + * MD5( handshake + sender + master + pad1 ) ) * + SHA1( master + pad2 + * SHA1( handshake + sender + master + pad1 ) ) */ #if !defined(POLARSSL_MD5_ALT) SSL_DEBUG_BUF( 4, "finished md5 state", (unsigned char *) md5.state, sizeof( md5.state ) ); #endif #if !defined(POLARSSL_SHA1_ALT) SSL_DEBUG_BUF( 4, "finished sha1 state", (unsigned char *) sha1.state, sizeof( sha1.state ) ); #endif sender = ( from == SSL_IS_CLIENT ) ? "CLNT" : "SRVR"; memset( padbuf, 0x36, 48 ); md5_update( &md5, (const unsigned char *) sender, 4 ); md5_update( &md5, session->master, 48 ); md5_update( &md5, padbuf, 48 ); md5_finish( &md5, md5sum ); sha1_update( &sha1, (const unsigned char *) sender, 4 ); sha1_update( &sha1, session->master, 48 ); sha1_update( &sha1, padbuf, 40 ); sha1_finish( &sha1, sha1sum ); memset( padbuf, 0x5C, 48 ); md5_starts( &md5 ); md5_update( &md5, session->master, 48 ); md5_update( &md5, padbuf, 48 ); md5_update( &md5, md5sum, 16 ); md5_finish( &md5, buf ); sha1_starts( &sha1 ); sha1_update( &sha1, session->master, 48 ); sha1_update( &sha1, padbuf , 40 ); sha1_update( &sha1, sha1sum, 20 ); sha1_finish( &sha1, buf + 16 ); SSL_DEBUG_BUF( 3, "calc finished result", buf, 36 ); md5_free( &md5 ); sha1_free( &sha1 ); polarssl_zeroize( padbuf, sizeof( padbuf ) ); polarssl_zeroize( md5sum, sizeof( md5sum ) ); polarssl_zeroize( sha1sum, sizeof( sha1sum ) ); SSL_DEBUG_MSG( 2, ( "<= calc finished" ) ); } #endif /* POLARSSL_SSL_PROTO_SSL3 */ #if defined(POLARSSL_SSL_PROTO_TLS1) || defined(POLARSSL_SSL_PROTO_TLS1_1) static void ssl_calc_finished_tls( ssl_context *ssl, unsigned char *buf, int from ) { int len = 12; const char *sender; md5_context md5; sha1_context sha1; unsigned char padbuf[36]; ssl_session *session = ssl->session_negotiate; if( !session ) session = ssl->session; SSL_DEBUG_MSG( 2, ( "=> calc finished tls" ) ); memcpy( &md5 , &ssl->handshake->fin_md5 , sizeof(md5_context) ); memcpy( &sha1, &ssl->handshake->fin_sha1, sizeof(sha1_context) ); /* * TLSv1: * hash = PRF( master, finished_label, * MD5( handshake ) + SHA1( handshake ) )[0..11] */ #if !defined(POLARSSL_MD5_ALT) SSL_DEBUG_BUF( 4, "finished md5 state", (unsigned char *) md5.state, sizeof( md5.state ) ); #endif #if !defined(POLARSSL_SHA1_ALT) SSL_DEBUG_BUF( 4, "finished sha1 state", (unsigned char *) sha1.state, sizeof( sha1.state ) ); #endif sender = ( from == SSL_IS_CLIENT ) ? "client finished" : "server finished"; md5_finish( &md5, padbuf ); sha1_finish( &sha1, padbuf + 16 ); ssl->handshake->tls_prf( session->master, 48, sender, padbuf, 36, buf, len ); SSL_DEBUG_BUF( 3, "calc finished result", buf, len ); md5_free( &md5 ); sha1_free( &sha1 ); polarssl_zeroize( padbuf, sizeof( padbuf ) ); SSL_DEBUG_MSG( 2, ( "<= calc finished" ) ); } #endif /* POLARSSL_SSL_PROTO_TLS1 || POLARSSL_SSL_PROTO_TLS1_1 */ #if defined(POLARSSL_SSL_PROTO_TLS1_2) #if defined(POLARSSL_SHA256_C) static void ssl_calc_finished_tls_sha256( ssl_context *ssl, unsigned char *buf, int from ) { int len = 12; const char *sender; sha256_context sha256; unsigned char padbuf[32]; ssl_session *session = ssl->session_negotiate; if( !session ) session = ssl->session; SSL_DEBUG_MSG( 2, ( "=> calc finished tls sha256" ) ); memcpy( &sha256, &ssl->handshake->fin_sha256, sizeof(sha256_context) ); /* * TLSv1.2: * hash = PRF( master, finished_label, * Hash( handshake ) )[0.11] */ #if !defined(POLARSSL_SHA256_ALT) SSL_DEBUG_BUF( 4, "finished sha2 state", (unsigned char *) sha256.state, sizeof( sha256.state ) ); #endif sender = ( from == SSL_IS_CLIENT ) ? "client finished" : "server finished"; sha256_finish( &sha256, padbuf ); ssl->handshake->tls_prf( session->master, 48, sender, padbuf, 32, buf, len ); SSL_DEBUG_BUF( 3, "calc finished result", buf, len ); sha256_free( &sha256 ); polarssl_zeroize( padbuf, sizeof( padbuf ) ); SSL_DEBUG_MSG( 2, ( "<= calc finished" ) ); } #endif /* POLARSSL_SHA256_C */ #if defined(POLARSSL_SHA512_C) static void ssl_calc_finished_tls_sha384( ssl_context *ssl, unsigned char *buf, int from ) { int len = 12; const char *sender; sha512_context sha512; unsigned char padbuf[48]; ssl_session *session = ssl->session_negotiate; if( !session ) session = ssl->session; SSL_DEBUG_MSG( 2, ( "=> calc finished tls sha384" ) ); memcpy( &sha512, &ssl->handshake->fin_sha512, sizeof(sha512_context) ); /* * TLSv1.2: * hash = PRF( master, finished_label, * Hash( handshake ) )[0.11] */ #if !defined(POLARSSL_SHA512_ALT) SSL_DEBUG_BUF( 4, "finished sha512 state", (unsigned char *) sha512.state, sizeof( sha512.state ) ); #endif sender = ( from == SSL_IS_CLIENT ) ? "client finished" : "server finished"; sha512_finish( &sha512, padbuf ); ssl->handshake->tls_prf( session->master, 48, sender, padbuf, 48, buf, len ); SSL_DEBUG_BUF( 3, "calc finished result", buf, len ); sha512_free( &sha512 ); polarssl_zeroize( padbuf, sizeof( padbuf ) ); SSL_DEBUG_MSG( 2, ( "<= calc finished" ) ); } #endif /* POLARSSL_SHA512_C */ #endif /* POLARSSL_SSL_PROTO_TLS1_2 */ void ssl_handshake_wrapup( ssl_context *ssl ) { int resume = ssl->handshake->resume; SSL_DEBUG_MSG( 3, ( "=> handshake wrapup" ) ); /* * Free our handshake params */ ssl_handshake_free( ssl->handshake ); polarssl_free( ssl->handshake ); ssl->handshake = NULL; if( ssl->renegotiation == SSL_RENEGOTIATION ) { ssl->renegotiation = SSL_RENEGOTIATION_DONE; ssl->renego_records_seen = 0; } /* * Switch in our now active transform context */ if( ssl->transform ) { ssl_transform_free( ssl->transform ); polarssl_free( ssl->transform ); } ssl->transform = ssl->transform_negotiate; ssl->transform_negotiate = NULL; if( ssl->session ) { ssl_session_free( ssl->session ); polarssl_free( ssl->session ); } ssl->session = ssl->session_negotiate; ssl->session_negotiate = NULL; /* * Add cache entry */ if( ssl->f_set_cache != NULL && ssl->session->length != 0 && resume == 0 ) { if( ssl->f_set_cache( ssl->p_set_cache, ssl->session ) != 0 ) SSL_DEBUG_MSG( 1, ( "cache did not store session" ) ); } ssl->state++; SSL_DEBUG_MSG( 3, ( "<= handshake wrapup" ) ); } int ssl_write_finished( ssl_context *ssl ) { int ret, hash_len; SSL_DEBUG_MSG( 2, ( "=> write finished" ) ); /* * Set the out_msg pointer to the correct location based on IV length */ if( ssl->minor_ver >= SSL_MINOR_VERSION_2 ) { ssl->out_msg = ssl->out_iv + ssl->transform_negotiate->ivlen - ssl->transform_negotiate->fixed_ivlen; } else ssl->out_msg = ssl->out_iv; ssl->handshake->calc_finished( ssl, ssl->out_msg + 4, ssl->endpoint ); // TODO TLS/1.2 Hash length is determined by cipher suite (Page 63) hash_len = ( ssl->minor_ver == SSL_MINOR_VERSION_0 ) ? 36 : 12; ssl->verify_data_len = hash_len; memcpy( ssl->own_verify_data, ssl->out_msg + 4, hash_len ); ssl->out_msglen = 4 + hash_len; ssl->out_msgtype = SSL_MSG_HANDSHAKE; ssl->out_msg[0] = SSL_HS_FINISHED; /* * In case of session resuming, invert the client and server * ChangeCipherSpec messages order. */ if( ssl->handshake->resume != 0 ) { if( ssl->endpoint == SSL_IS_CLIENT ) ssl->state = SSL_HANDSHAKE_WRAPUP; else ssl->state = SSL_CLIENT_CHANGE_CIPHER_SPEC; } else ssl->state++; /* * Switch to our negotiated transform and session parameters for outbound * data. */ SSL_DEBUG_MSG( 3, ( "switching to new transform spec for outbound data" ) ); ssl->transform_out = ssl->transform_negotiate; ssl->session_out = ssl->session_negotiate; #if defined(POLARSSL_SSL_PROTO_DTLS) if( ssl->transport == SSL_TRANSPORT_DATAGRAM ) { unsigned char i; /* Set sequence_number to zero */ memset( ssl->out_ctr + 2, 0, 6 ); /* Increment epoch */ for( i = 2; i > 0; i-- ) if( ++ssl->out_ctr[i - 1] != 0 ) break; /* The loop goes to its end iff the counter is wrapping */ if( i == 0 ) { SSL_DEBUG_MSG( 1, ( "DTLS epoch would wrap" ) ); return( POLARSSL_ERR_SSL_COUNTER_WRAPPING ); } } else #endif /* POLARSSL_SSL_PROTO_DTLS */ memset( ssl->out_ctr, 0, 8 ); #if defined(POLARSSL_SSL_HW_RECORD_ACCEL) if( ssl_hw_record_activate != NULL ) { if( ( ret = ssl_hw_record_activate( ssl, SSL_CHANNEL_OUTBOUND ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_hw_record_activate", ret ); return( POLARSSL_ERR_SSL_HW_ACCEL_FAILED ); } } #endif if( ( ret = ssl_write_record( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_write_record", ret ); return( ret ); } SSL_DEBUG_MSG( 2, ( "<= write finished" ) ); return( 0 ); } int ssl_parse_finished( ssl_context *ssl ) { int ret; unsigned int hash_len; unsigned char buf[36]; SSL_DEBUG_MSG( 2, ( "=> parse finished" ) ); ssl->handshake->calc_finished( ssl, buf, ssl->endpoint ^ 1 ); /* * Switch to our negotiated transform and session parameters for inbound * data. */ SSL_DEBUG_MSG( 3, ( "switching to new transform spec for inbound data" ) ); ssl->transform_in = ssl->transform_negotiate; ssl->session_in = ssl->session_negotiate; /* Input counter/epoch not used with DTLS right now, * but it doesn't hurt to have this part ready */ #if defined(POLARSSL_SSL_PROTO_DTLS) if( ssl->transport == SSL_TRANSPORT_DATAGRAM ) { unsigned char i; /* Set sequence_number to zero */ memset( ssl->in_ctr + 2, 0, 6 ); /* Increment epoch */ for( i = 2; i > 0; i-- ) if( ++ssl->in_ctr[i - 1] != 0 ) break; /* The loop goes to its end iff the counter is wrapping */ if( i == 0 ) { SSL_DEBUG_MSG( 1, ( "DTLS epoch would wrap" ) ); return( POLARSSL_ERR_SSL_COUNTER_WRAPPING ); } } else #endif /* POLARSSL_SSL_PROTO_DTLS */ memset( ssl->in_ctr, 0, 8 ); /* * Set the in_msg pointer to the correct location based on IV length */ if( ssl->minor_ver >= SSL_MINOR_VERSION_2 ) { ssl->in_msg = ssl->in_iv + ssl->transform_negotiate->ivlen - ssl->transform_negotiate->fixed_ivlen; } else ssl->in_msg = ssl->in_iv; #if defined(POLARSSL_SSL_HW_RECORD_ACCEL) if( ssl_hw_record_activate != NULL ) { if( ( ret = ssl_hw_record_activate( ssl, SSL_CHANNEL_INBOUND ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_hw_record_activate", ret ); return( POLARSSL_ERR_SSL_HW_ACCEL_FAILED ); } } #endif if( ( ret = ssl_read_record( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_read_record", ret ); return( ret ); } if( ssl->in_msgtype != SSL_MSG_HANDSHAKE ) { SSL_DEBUG_MSG( 1, ( "bad finished message" ) ); return( POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE ); } // TODO TLS/1.2 Hash length is determined by cipher suite (Page 63) hash_len = ( ssl->minor_ver == SSL_MINOR_VERSION_0 ) ? 36 : 12; if( ssl->in_msg[0] != SSL_HS_FINISHED || ssl->in_hslen != 4 + hash_len ) { SSL_DEBUG_MSG( 1, ( "bad finished message" ) ); return( POLARSSL_ERR_SSL_BAD_HS_FINISHED ); } if( safer_memcmp( ssl->in_msg + 4, buf, hash_len ) != 0 ) { SSL_DEBUG_MSG( 1, ( "bad finished message" ) ); return( POLARSSL_ERR_SSL_BAD_HS_FINISHED ); } ssl->verify_data_len = hash_len; memcpy( ssl->peer_verify_data, buf, hash_len ); if( ssl->handshake->resume != 0 ) { if( ssl->endpoint == SSL_IS_CLIENT ) ssl->state = SSL_CLIENT_CHANGE_CIPHER_SPEC; if( ssl->endpoint == SSL_IS_SERVER ) ssl->state = SSL_HANDSHAKE_WRAPUP; } else ssl->state++; SSL_DEBUG_MSG( 2, ( "<= parse finished" ) ); return( 0 ); } static void ssl_handshake_params_init( ssl_handshake_params *handshake ) { memset( handshake, 0, sizeof( ssl_handshake_params ) ); #if defined(POLARSSL_SSL_PROTO_SSL3) || defined(POLARSSL_SSL_PROTO_TLS1) || \ defined(POLARSSL_SSL_PROTO_TLS1_1) md5_init( &handshake->fin_md5 ); sha1_init( &handshake->fin_sha1 ); md5_starts( &handshake->fin_md5 ); sha1_starts( &handshake->fin_sha1 ); #endif #if defined(POLARSSL_SSL_PROTO_TLS1_2) #if defined(POLARSSL_SHA256_C) sha256_init( &handshake->fin_sha256 ); sha256_starts( &handshake->fin_sha256, 0 ); #endif #if defined(POLARSSL_SHA512_C) sha512_init( &handshake->fin_sha512 ); sha512_starts( &handshake->fin_sha512, 1 ); #endif #endif /* POLARSSL_SSL_PROTO_TLS1_2 */ handshake->update_checksum = ssl_update_checksum_start; handshake->sig_alg = SSL_HASH_SHA1; #if defined(POLARSSL_DHM_C) dhm_init( &handshake->dhm_ctx ); #endif #if defined(POLARSSL_ECDH_C) ecdh_init( &handshake->ecdh_ctx ); #endif } static void ssl_transform_init( ssl_transform *transform ) { memset( transform, 0, sizeof(ssl_transform) ); cipher_init( &transform->cipher_ctx_enc ); cipher_init( &transform->cipher_ctx_dec ); md_init( &transform->md_ctx_enc ); md_init( &transform->md_ctx_dec ); } void ssl_session_init( ssl_session *session ) { memset( session, 0, sizeof(ssl_session) ); } static int ssl_handshake_init( ssl_context *ssl ) { /* Clear old handshake information if present */ if( ssl->transform_negotiate ) ssl_transform_free( ssl->transform_negotiate ); if( ssl->session_negotiate ) ssl_session_free( ssl->session_negotiate ); if( ssl->handshake ) ssl_handshake_free( ssl->handshake ); /* * Either the pointers are now NULL or cleared properly and can be freed. * Now allocate missing structures. */ if( ssl->transform_negotiate == NULL ) { ssl->transform_negotiate = (ssl_transform *) polarssl_malloc( sizeof(ssl_transform) ); } if( ssl->session_negotiate == NULL ) { ssl->session_negotiate = (ssl_session *) polarssl_malloc( sizeof(ssl_session) ); } if( ssl->handshake == NULL ) { ssl->handshake = (ssl_handshake_params *) polarssl_malloc( sizeof(ssl_handshake_params) ); } /* All pointers should exist and can be directly freed without issue */ if( ssl->handshake == NULL || ssl->transform_negotiate == NULL || ssl->session_negotiate == NULL ) { SSL_DEBUG_MSG( 1, ( "malloc() of ssl sub-contexts failed" ) ); polarssl_free( ssl->handshake ); polarssl_free( ssl->transform_negotiate ); polarssl_free( ssl->session_negotiate ); ssl->handshake = NULL; ssl->transform_negotiate = NULL; ssl->session_negotiate = NULL; return( POLARSSL_ERR_SSL_MALLOC_FAILED ); } /* Initialize structures */ ssl_session_init( ssl->session_negotiate ); ssl_transform_init( ssl->transform_negotiate ); ssl_handshake_params_init( ssl->handshake ); #if defined(POLARSSL_X509_CRT_PARSE_C) ssl->handshake->key_cert = ssl->key_cert; #endif return( 0 ); } #if defined(POLARSSL_SSL_DTLS_HELLO_VERIFY) /* Dummy cookie callbacks for defaults */ static int ssl_cookie_write_dummy( void *ctx, unsigned char **p, unsigned char *end, const unsigned char *cli_id, size_t cli_id_len ) { ((void) ctx); ((void) p); ((void) end); ((void) cli_id); ((void) cli_id_len); return( POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE ); } static int ssl_cookie_check_dummy( void *ctx, const unsigned char *cookie, size_t cookie_len, const unsigned char *cli_id, size_t cli_id_len ) { ((void) ctx); ((void) cookie); ((void) cookie_len); ((void) cli_id); ((void) cli_id_len); return( POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE ); } #endif /* POLARSSL_SSL_DTLS_HELLO_VERIFY */ /* * Initialize an SSL context */ int ssl_init( ssl_context *ssl ) { int ret; int len = SSL_BUFFER_LEN; memset( ssl, 0, sizeof( ssl_context ) ); /* * Sane defaults */ ssl->min_major_ver = SSL_MIN_MAJOR_VERSION; ssl->min_minor_ver = SSL_MIN_MINOR_VERSION; ssl->max_major_ver = SSL_MAX_MAJOR_VERSION; ssl->max_minor_ver = SSL_MAX_MINOR_VERSION; ssl_set_ciphersuites( ssl, ssl_list_ciphersuites() ); ssl->renego_max_records = SSL_RENEGO_MAX_RECORDS_DEFAULT; #if defined(POLARSSL_DHM_C) if( ( ret = mpi_read_string( &ssl->dhm_P, 16, POLARSSL_DHM_RFC5114_MODP_1024_P) ) != 0 || ( ret = mpi_read_string( &ssl->dhm_G, 16, POLARSSL_DHM_RFC5114_MODP_1024_G) ) != 0 ) { SSL_DEBUG_RET( 1, "mpi_read_string", ret ); return( ret ); } #endif /* * Prepare base structures */ ssl->in_buf = (unsigned char *) polarssl_malloc( len ); ssl->out_buf = (unsigned char *) polarssl_malloc( len ); if( ssl->in_buf == NULL || ssl->out_buf == NULL ) { SSL_DEBUG_MSG( 1, ( "malloc(%d bytes) failed", len ) ); polarssl_free( ssl->in_buf ); polarssl_free( ssl->out_buf ); ssl->in_buf = NULL; ssl->out_buf = NULL; return( POLARSSL_ERR_SSL_MALLOC_FAILED ); } memset( ssl-> in_buf, 0, SSL_BUFFER_LEN ); memset( ssl->out_buf, 0, SSL_BUFFER_LEN ); /* No error is possible, SSL_TRANSPORT_STREAM always valid */ (void) ssl_set_transport( ssl, SSL_TRANSPORT_STREAM ); #if defined(POLARSSL_SSL_SESSION_TICKETS) ssl->ticket_lifetime = SSL_DEFAULT_TICKET_LIFETIME; #endif #if defined(POLARSSL_SSL_SET_CURVES) ssl->curve_list = ecp_grp_id_list( ); #endif #if defined(POLARSSL_SSL_DTLS_HELLO_VERIFY) ssl->f_cookie_write = ssl_cookie_write_dummy; ssl->f_cookie_check = ssl_cookie_check_dummy; #endif if( ( ret = ssl_handshake_init( ssl ) ) != 0 ) return( ret ); return( 0 ); } /* * Reset an initialized and used SSL context for re-use while retaining * all application-set variables, function pointers and data. */ int ssl_session_reset( ssl_context *ssl ) { int ret; ssl->state = SSL_HELLO_REQUEST; ssl->renegotiation = SSL_INITIAL_HANDSHAKE; ssl->secure_renegotiation = SSL_LEGACY_RENEGOTIATION; ssl->verify_data_len = 0; memset( ssl->own_verify_data, 0, 36 ); memset( ssl->peer_verify_data, 0, 36 ); ssl->in_offt = NULL; ssl->in_msg = ssl->in_buf + 13; ssl->in_msgtype = 0; ssl->in_msglen = 0; ssl->in_left = 0; #if defined(POLARSSL_SSL_PROTO_DTLS) ssl->next_record_offset = 0; #endif ssl->in_hslen = 0; ssl->nb_zero = 0; ssl->record_read = 0; ssl->out_msg = ssl->out_buf + 13; ssl->out_msgtype = 0; ssl->out_msglen = 0; ssl->out_left = 0; ssl->transform_in = NULL; ssl->transform_out = NULL; ssl->renego_records_seen = 0; memset( ssl->out_buf, 0, SSL_BUFFER_LEN ); memset( ssl->in_buf, 0, SSL_BUFFER_LEN ); #if defined(POLARSSL_SSL_HW_RECORD_ACCEL) if( ssl_hw_record_reset != NULL ) { SSL_DEBUG_MSG( 2, ( "going for ssl_hw_record_reset()" ) ); if( ( ret = ssl_hw_record_reset( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_hw_record_reset", ret ); return( POLARSSL_ERR_SSL_HW_ACCEL_FAILED ); } } #endif if( ssl->transform ) { ssl_transform_free( ssl->transform ); polarssl_free( ssl->transform ); ssl->transform = NULL; } if( ssl->session ) { ssl_session_free( ssl->session ); polarssl_free( ssl->session ); ssl->session = NULL; } #if defined(POLARSSL_SSL_ALPN) ssl->alpn_chosen = NULL; #endif #if defined(POLARSSL_SSL_DTLS_HELLO_VERIFY) polarssl_free( ssl->cli_id ); ssl->cli_id = NULL; ssl->cli_id_len = 0; #endif if( ( ret = ssl_handshake_init( ssl ) ) != 0 ) return( ret ); return( 0 ); } #if defined(POLARSSL_SSL_SESSION_TICKETS) static void ssl_ticket_keys_free( ssl_ticket_keys *tkeys ) { aes_free( &tkeys->enc ); aes_free( &tkeys->dec ); polarssl_zeroize( tkeys, sizeof(ssl_ticket_keys) ); } /* * Allocate and initialize ticket keys */ static int ssl_ticket_keys_init( ssl_context *ssl ) { int ret; ssl_ticket_keys *tkeys; unsigned char buf[16]; if( ssl->ticket_keys != NULL ) return( 0 ); tkeys = (ssl_ticket_keys *) polarssl_malloc( sizeof(ssl_ticket_keys) ); if( tkeys == NULL ) return( POLARSSL_ERR_SSL_MALLOC_FAILED ); aes_init( &tkeys->enc ); aes_init( &tkeys->dec ); if( ( ret = ssl->f_rng( ssl->p_rng, tkeys->key_name, 16 ) ) != 0 ) { ssl_ticket_keys_free( tkeys ); polarssl_free( tkeys ); return( ret ); } if( ( ret = ssl->f_rng( ssl->p_rng, buf, 16 ) ) != 0 || ( ret = aes_setkey_enc( &tkeys->enc, buf, 128 ) ) != 0 || ( ret = aes_setkey_dec( &tkeys->dec, buf, 128 ) ) != 0 ) { ssl_ticket_keys_free( tkeys ); polarssl_free( tkeys ); return( ret ); } if( ( ret = ssl->f_rng( ssl->p_rng, tkeys->mac_key, 16 ) ) != 0 ) { ssl_ticket_keys_free( tkeys ); polarssl_free( tkeys ); return( ret ); } ssl->ticket_keys = tkeys; return( 0 ); } #endif /* POLARSSL_SSL_SESSION_TICKETS */ /* * SSL set accessors */ void ssl_set_endpoint( ssl_context *ssl, int endpoint ) { ssl->endpoint = endpoint; #if defined(POLARSSL_SSL_SESSION_TICKETS) if( endpoint == SSL_IS_CLIENT ) ssl->session_tickets = SSL_SESSION_TICKETS_ENABLED; #endif } int ssl_set_transport( ssl_context *ssl, int transport ) { #if defined(POLARSSL_SSL_PROTO_DTLS) if( transport == SSL_TRANSPORT_DATAGRAM ) { ssl->transport = transport; ssl->out_hdr = ssl->out_buf; ssl->out_ctr = ssl->out_buf + 3; ssl->out_len = ssl->out_buf + 11; ssl->out_iv = ssl->out_buf + 13; ssl->out_msg = ssl->out_buf + 13; ssl->in_hdr = ssl->in_buf; ssl->in_ctr = ssl->in_buf + 3; ssl->in_len = ssl->in_buf + 11; ssl->in_iv = ssl->in_buf + 13; ssl->in_msg = ssl->in_buf + 13; /* DTLS starts with TLS1.1 */ if( ssl->min_minor_ver < SSL_MINOR_VERSION_2 ) ssl->min_minor_ver = SSL_MINOR_VERSION_2; if( ssl->max_minor_ver < SSL_MINOR_VERSION_2 ) ssl->max_minor_ver = SSL_MINOR_VERSION_2; return( 0 ); } #endif if( transport == SSL_TRANSPORT_STREAM ) { ssl->transport = transport; ssl->out_ctr = ssl->out_buf; ssl->out_hdr = ssl->out_buf + 8; ssl->out_len = ssl->out_buf + 11; ssl->out_iv = ssl->out_buf + 13; ssl->out_msg = ssl->out_buf + 13; ssl->in_ctr = ssl->in_buf; ssl->in_hdr = ssl->in_buf + 8; ssl->in_len = ssl->in_buf + 11; ssl->in_iv = ssl->in_buf + 13; ssl->in_msg = ssl->in_buf + 13; return( 0 ); } return( POLARSSL_ERR_SSL_BAD_INPUT_DATA ); } void ssl_set_authmode( ssl_context *ssl, int authmode ) { ssl->authmode = authmode; } #if defined(POLARSSL_X509_CRT_PARSE_C) void ssl_set_verify( ssl_context *ssl, int (*f_vrfy)(void *, x509_crt *, int, int *), void *p_vrfy ) { ssl->f_vrfy = f_vrfy; ssl->p_vrfy = p_vrfy; } #endif /* POLARSSL_X509_CRT_PARSE_C */ void ssl_set_rng( ssl_context *ssl, int (*f_rng)(void *, unsigned char *, size_t), void *p_rng ) { ssl->f_rng = f_rng; ssl->p_rng = p_rng; } void ssl_set_dbg( ssl_context *ssl, void (*f_dbg)(void *, int, const char *), void *p_dbg ) { ssl->f_dbg = f_dbg; ssl->p_dbg = p_dbg; } void ssl_set_bio( ssl_context *ssl, int (*f_recv)(void *, unsigned char *, size_t), void *p_recv, int (*f_send)(void *, const unsigned char *, size_t), void *p_send ) { ssl->f_recv = f_recv; ssl->f_send = f_send; ssl->p_recv = p_recv; ssl->p_send = p_send; } void ssl_set_session_cache( ssl_context *ssl, int (*f_get_cache)(void *, ssl_session *), void *p_get_cache, int (*f_set_cache)(void *, const ssl_session *), void *p_set_cache ) { ssl->f_get_cache = f_get_cache; ssl->p_get_cache = p_get_cache; ssl->f_set_cache = f_set_cache; ssl->p_set_cache = p_set_cache; } int ssl_set_session( ssl_context *ssl, const ssl_session *session ) { int ret; if( ssl == NULL || session == NULL || ssl->session_negotiate == NULL || ssl->endpoint != SSL_IS_CLIENT ) { return( POLARSSL_ERR_SSL_BAD_INPUT_DATA ); } if( ( ret = ssl_session_copy( ssl->session_negotiate, session ) ) != 0 ) return( ret ); ssl->handshake->resume = 1; return( 0 ); } void ssl_set_ciphersuites( ssl_context *ssl, const int *ciphersuites ) { ssl->ciphersuite_list[SSL_MINOR_VERSION_0] = ciphersuites; ssl->ciphersuite_list[SSL_MINOR_VERSION_1] = ciphersuites; ssl->ciphersuite_list[SSL_MINOR_VERSION_2] = ciphersuites; ssl->ciphersuite_list[SSL_MINOR_VERSION_3] = ciphersuites; } void ssl_set_ciphersuites_for_version( ssl_context *ssl, const int *ciphersuites, int major, int minor ) { if( major != SSL_MAJOR_VERSION_3 ) return; if( minor < SSL_MINOR_VERSION_0 || minor > SSL_MINOR_VERSION_3 ) return; ssl->ciphersuite_list[minor] = ciphersuites; } #if defined(POLARSSL_X509_CRT_PARSE_C) /* Add a new (empty) key_cert entry an return a pointer to it */ static ssl_key_cert *ssl_add_key_cert( ssl_context *ssl ) { ssl_key_cert *key_cert, *last; key_cert = (ssl_key_cert *) polarssl_malloc( sizeof(ssl_key_cert) ); if( key_cert == NULL ) return( NULL ); memset( key_cert, 0, sizeof( ssl_key_cert ) ); /* Append the new key_cert to the (possibly empty) current list */ if( ssl->key_cert == NULL ) { ssl->key_cert = key_cert; if( ssl->handshake != NULL ) ssl->handshake->key_cert = key_cert; } else { last = ssl->key_cert; while( last->next != NULL ) last = last->next; last->next = key_cert; } return( key_cert ); } void ssl_set_ca_chain( ssl_context *ssl, x509_crt *ca_chain, x509_crl *ca_crl, const char *peer_cn ) { ssl->ca_chain = ca_chain; ssl->ca_crl = ca_crl; ssl->peer_cn = peer_cn; } int ssl_set_own_cert( ssl_context *ssl, x509_crt *own_cert, pk_context *pk_key ) { ssl_key_cert *key_cert = ssl_add_key_cert( ssl ); if( key_cert == NULL ) return( POLARSSL_ERR_SSL_MALLOC_FAILED ); key_cert->cert = own_cert; key_cert->key = pk_key; return( 0 ); } #if defined(POLARSSL_RSA_C) int ssl_set_own_cert_rsa( ssl_context *ssl, x509_crt *own_cert, rsa_context *rsa_key ) { int ret; ssl_key_cert *key_cert = ssl_add_key_cert( ssl ); if( key_cert == NULL ) return( POLARSSL_ERR_SSL_MALLOC_FAILED ); key_cert->key = (pk_context *) polarssl_malloc( sizeof(pk_context) ); if( key_cert->key == NULL ) return( POLARSSL_ERR_SSL_MALLOC_FAILED ); pk_init( key_cert->key ); ret = pk_init_ctx( key_cert->key, pk_info_from_type( POLARSSL_PK_RSA ) ); if( ret != 0 ) return( ret ); if( ( ret = rsa_copy( pk_rsa( *key_cert->key ), rsa_key ) ) != 0 ) return( ret ); key_cert->cert = own_cert; key_cert->key_own_alloc = 1; return( 0 ); } #endif /* POLARSSL_RSA_C */ int ssl_set_own_cert_alt( ssl_context *ssl, x509_crt *own_cert, void *rsa_key, rsa_decrypt_func rsa_decrypt, rsa_sign_func rsa_sign, rsa_key_len_func rsa_key_len ) { int ret; ssl_key_cert *key_cert = ssl_add_key_cert( ssl ); if( key_cert == NULL ) return( POLARSSL_ERR_SSL_MALLOC_FAILED ); key_cert->key = (pk_context *) polarssl_malloc( sizeof(pk_context) ); if( key_cert->key == NULL ) return( POLARSSL_ERR_SSL_MALLOC_FAILED ); pk_init( key_cert->key ); if( ( ret = pk_init_ctx_rsa_alt( key_cert->key, rsa_key, rsa_decrypt, rsa_sign, rsa_key_len ) ) != 0 ) return( ret ); key_cert->cert = own_cert; key_cert->key_own_alloc = 1; return( 0 ); } #endif /* POLARSSL_X509_CRT_PARSE_C */ #if defined(POLARSSL_KEY_EXCHANGE__SOME__PSK_ENABLED) int ssl_set_psk( ssl_context *ssl, const unsigned char *psk, size_t psk_len, const unsigned char *psk_identity, size_t psk_identity_len ) { if( psk == NULL || psk_identity == NULL ) return( POLARSSL_ERR_SSL_BAD_INPUT_DATA ); if( psk_len > POLARSSL_PSK_MAX_LEN ) return( POLARSSL_ERR_SSL_BAD_INPUT_DATA ); if( ssl->psk != NULL ) { polarssl_free( ssl->psk ); polarssl_free( ssl->psk_identity ); } ssl->psk_len = psk_len; ssl->psk_identity_len = psk_identity_len; ssl->psk = (unsigned char *) polarssl_malloc( ssl->psk_len ); ssl->psk_identity = (unsigned char *) polarssl_malloc( ssl->psk_identity_len ); if( ssl->psk == NULL || ssl->psk_identity == NULL ) return( POLARSSL_ERR_SSL_MALLOC_FAILED ); memcpy( ssl->psk, psk, ssl->psk_len ); memcpy( ssl->psk_identity, psk_identity, ssl->psk_identity_len ); return( 0 ); } void ssl_set_psk_cb( ssl_context *ssl, int (*f_psk)(void *, ssl_context *, const unsigned char *, size_t), void *p_psk ) { ssl->f_psk = f_psk; ssl->p_psk = p_psk; } #endif /* POLARSSL_KEY_EXCHANGE__SOME__PSK_ENABLED */ #if defined(POLARSSL_DHM_C) int ssl_set_dh_param( ssl_context *ssl, const char *dhm_P, const char *dhm_G ) { int ret; if( ( ret = mpi_read_string( &ssl->dhm_P, 16, dhm_P ) ) != 0 ) { SSL_DEBUG_RET( 1, "mpi_read_string", ret ); return( ret ); } if( ( ret = mpi_read_string( &ssl->dhm_G, 16, dhm_G ) ) != 0 ) { SSL_DEBUG_RET( 1, "mpi_read_string", ret ); return( ret ); } return( 0 ); } int ssl_set_dh_param_ctx( ssl_context *ssl, dhm_context *dhm_ctx ) { int ret; if( ( ret = mpi_copy( &ssl->dhm_P, &dhm_ctx->P ) ) != 0 ) { SSL_DEBUG_RET( 1, "mpi_copy", ret ); return( ret ); } if( ( ret = mpi_copy( &ssl->dhm_G, &dhm_ctx->G ) ) != 0 ) { SSL_DEBUG_RET( 1, "mpi_copy", ret ); return( ret ); } return( 0 ); } #endif /* POLARSSL_DHM_C */ #if defined(POLARSSL_SSL_SET_CURVES) /* * Set the allowed elliptic curves */ void ssl_set_curves( ssl_context *ssl, const ecp_group_id *curve_list ) { ssl->curve_list = curve_list; } #endif #if defined(POLARSSL_SSL_SERVER_NAME_INDICATION) int ssl_set_hostname( ssl_context *ssl, const char *hostname ) { if( hostname == NULL ) return( POLARSSL_ERR_SSL_BAD_INPUT_DATA ); ssl->hostname_len = strlen( hostname ); if( ssl->hostname_len + 1 == 0 ) return( POLARSSL_ERR_SSL_BAD_INPUT_DATA ); ssl->hostname = (unsigned char *) polarssl_malloc( ssl->hostname_len + 1 ); if( ssl->hostname == NULL ) return( POLARSSL_ERR_SSL_MALLOC_FAILED ); memcpy( ssl->hostname, (const unsigned char *) hostname, ssl->hostname_len ); ssl->hostname[ssl->hostname_len] = '\0'; return( 0 ); } void ssl_set_sni( ssl_context *ssl, int (*f_sni)(void *, ssl_context *, const unsigned char *, size_t), void *p_sni ) { ssl->f_sni = f_sni; ssl->p_sni = p_sni; } #endif /* POLARSSL_SSL_SERVER_NAME_INDICATION */ #if defined(POLARSSL_SSL_ALPN) int ssl_set_alpn_protocols( ssl_context *ssl, const char **protos ) { size_t cur_len, tot_len; const char **p; /* * "Empty strings MUST NOT be included and byte strings MUST NOT be * truncated". Check lengths now rather than later. */ tot_len = 0; for( p = protos; *p != NULL; p++ ) { cur_len = strlen( *p ); tot_len += cur_len; if( cur_len == 0 || cur_len > 255 || tot_len > 65535 ) return( POLARSSL_ERR_SSL_BAD_INPUT_DATA ); } ssl->alpn_list = protos; return( 0 ); } const char *ssl_get_alpn_protocol( const ssl_context *ssl ) { return( ssl->alpn_chosen ); } #endif /* POLARSSL_SSL_ALPN */ static int ssl_check_version( const ssl_context *ssl, int major, int minor ) { if( major < SSL_MIN_MAJOR_VERSION || major > SSL_MAX_MAJOR_VERSION || minor < SSL_MIN_MINOR_VERSION || minor > SSL_MAX_MINOR_VERSION || ( ssl->transport == SSL_TRANSPORT_DATAGRAM && minor < SSL_MINOR_VERSION_2 ) ) { return( -1 ); } return( 0 ); } int ssl_set_max_version( ssl_context *ssl, int major, int minor ) { if( ssl_check_version( ssl, major, minor ) != 0 ) return( POLARSSL_ERR_SSL_BAD_INPUT_DATA ); ssl->max_major_ver = major; ssl->max_minor_ver = minor; return( 0 ); } int ssl_set_min_version( ssl_context *ssl, int major, int minor ) { if( ssl_check_version( ssl, major, minor ) != 0 ) return( POLARSSL_ERR_SSL_BAD_INPUT_DATA ); ssl->min_major_ver = major; ssl->min_minor_ver = minor; return( 0 ); } #if defined(POLARSSL_SSL_MAX_FRAGMENT_LENGTH) int ssl_set_max_frag_len( ssl_context *ssl, unsigned char mfl_code ) { if( mfl_code >= SSL_MAX_FRAG_LEN_INVALID || mfl_code_to_length[mfl_code] > SSL_MAX_CONTENT_LEN ) { return( POLARSSL_ERR_SSL_BAD_INPUT_DATA ); } ssl->mfl_code = mfl_code; return( 0 ); } #endif /* POLARSSL_SSL_MAX_FRAGMENT_LENGTH */ #if defined(POLARSSL_SSL_TRUNCATED_HMAC) int ssl_set_truncated_hmac( ssl_context *ssl, int truncate ) { if( ssl->endpoint != SSL_IS_CLIENT ) return( POLARSSL_ERR_SSL_BAD_INPUT_DATA ); ssl->trunc_hmac = truncate; return( 0 ); } #endif /* POLARSSL_SSL_TRUNCATED_HMAC */ void ssl_set_renegotiation( ssl_context *ssl, int renegotiation ) { ssl->disable_renegotiation = renegotiation; } void ssl_legacy_renegotiation( ssl_context *ssl, int allow_legacy ) { ssl->allow_legacy_renegotiation = allow_legacy; } void ssl_set_renegotiation_enforced( ssl_context *ssl, int max_records ) { ssl->renego_max_records = max_records; } #if defined(POLARSSL_SSL_SESSION_TICKETS) int ssl_set_session_tickets( ssl_context *ssl, int use_tickets ) { ssl->session_tickets = use_tickets; if( ssl->endpoint == SSL_IS_CLIENT ) return( 0 ); if( ssl->f_rng == NULL ) return( POLARSSL_ERR_SSL_BAD_INPUT_DATA ); return( ssl_ticket_keys_init( ssl ) ); } void ssl_set_session_ticket_lifetime( ssl_context *ssl, int lifetime ) { ssl->ticket_lifetime = lifetime; } #endif /* POLARSSL_SSL_SESSION_TICKETS */ /* * SSL get accessors */ size_t ssl_get_bytes_avail( const ssl_context *ssl ) { return( ssl->in_offt == NULL ? 0 : ssl->in_msglen ); } int ssl_get_verify_result( const ssl_context *ssl ) { return( ssl->session->verify_result ); } const char *ssl_get_ciphersuite( const ssl_context *ssl ) { if( ssl == NULL || ssl->session == NULL ) return( NULL ); return ssl_get_ciphersuite_name( ssl->session->ciphersuite ); } const char *ssl_get_version( const ssl_context *ssl ) { #if defined(POLARSSL_SSL_PROTO_DTLS) if( ssl->transport == SSL_TRANSPORT_DATAGRAM ) { switch( ssl->minor_ver ) { case SSL_MINOR_VERSION_2: return( "DTLSv1.0" ); case SSL_MINOR_VERSION_3: return( "DTLSv1.2" ); default: return( "unknown (DTLS)" ); } } #endif switch( ssl->minor_ver ) { case SSL_MINOR_VERSION_0: return( "SSLv3.0" ); case SSL_MINOR_VERSION_1: return( "TLSv1.0" ); case SSL_MINOR_VERSION_2: return( "TLSv1.1" ); case SSL_MINOR_VERSION_3: return( "TLSv1.2" ); default: return( "unknown" ); } } #if defined(POLARSSL_X509_CRT_PARSE_C) const x509_crt *ssl_get_peer_cert( const ssl_context *ssl ) { if( ssl == NULL || ssl->session == NULL ) return( NULL ); return( ssl->session->peer_cert ); } #endif /* POLARSSL_X509_CRT_PARSE_C */ int ssl_get_session( const ssl_context *ssl, ssl_session *dst ) { if( ssl == NULL || dst == NULL || ssl->session == NULL || ssl->endpoint != SSL_IS_CLIENT ) { return( POLARSSL_ERR_SSL_BAD_INPUT_DATA ); } return( ssl_session_copy( dst, ssl->session ) ); } /* * Perform a single step of the SSL handshake */ int ssl_handshake_step( ssl_context *ssl ) { int ret = POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE; #if defined(POLARSSL_SSL_CLI_C) if( ssl->endpoint == SSL_IS_CLIENT ) ret = ssl_handshake_client_step( ssl ); #endif #if defined(POLARSSL_SSL_SRV_C) if( ssl->endpoint == SSL_IS_SERVER ) ret = ssl_handshake_server_step( ssl ); #endif return( ret ); } /* * Perform the SSL handshake */ int ssl_handshake( ssl_context *ssl ) { int ret = 0; SSL_DEBUG_MSG( 2, ( "=> handshake" ) ); while( ssl->state != SSL_HANDSHAKE_OVER ) { ret = ssl_handshake_step( ssl ); if( ret != 0 ) break; } SSL_DEBUG_MSG( 2, ( "<= handshake" ) ); return( ret ); } #if defined(POLARSSL_SSL_SRV_C) /* * Write HelloRequest to request renegotiation on server */ static int ssl_write_hello_request( ssl_context *ssl ) { int ret; SSL_DEBUG_MSG( 2, ( "=> write hello request" ) ); ssl->out_msglen = 4; ssl->out_msgtype = SSL_MSG_HANDSHAKE; ssl->out_msg[0] = SSL_HS_HELLO_REQUEST; if( ( ret = ssl_write_record( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_write_record", ret ); return( ret ); } SSL_DEBUG_MSG( 2, ( "<= write hello request" ) ); return( 0 ); } #endif /* POLARSSL_SSL_SRV_C */ /* * Actually renegotiate current connection, triggered by either: * - any side: calling ssl_renegotiate(), * - client: receiving a HelloRequest during ssl_read(), * - server: receiving any handshake message on server during ssl_read() after * the initial handshake is completed. * If the handshake doesn't complete due to waiting for I/O, it will continue * during the next calls to ssl_renegotiate() or ssl_read() respectively. */ static int ssl_start_renegotiation( ssl_context *ssl ) { int ret; SSL_DEBUG_MSG( 2, ( "=> renegotiate" ) ); if( ( ret = ssl_handshake_init( ssl ) ) != 0 ) return( ret ); /* RFC 6347 4.2.2: "[...] the HelloRequest will have message_seq = 0 and * the ServerHello will have message_seq = 1" */ #if defined(POLARSSL_SSL_PROTO_DTLS) if( ssl->transport == SSL_TRANSPORT_DATAGRAM && ssl->renegotiation == SSL_RENEGOTIATION_PENDING ) { if( ssl->endpoint == SSL_IS_SERVER ) ssl->handshake->out_msg_seq = 1; else ssl->handshake->in_msg_seq = 1; } #endif ssl->state = SSL_HELLO_REQUEST; ssl->renegotiation = SSL_RENEGOTIATION; if( ( ret = ssl_handshake( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_handshake", ret ); return( ret ); } SSL_DEBUG_MSG( 2, ( "<= renegotiate" ) ); return( 0 ); } /* * Renegotiate current connection on client, * or request renegotiation on server */ int ssl_renegotiate( ssl_context *ssl ) { int ret = POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE; #if defined(POLARSSL_SSL_SRV_C) /* On server, just send the request */ if( ssl->endpoint == SSL_IS_SERVER ) { if( ssl->state != SSL_HANDSHAKE_OVER ) return( POLARSSL_ERR_SSL_BAD_INPUT_DATA ); ssl->renegotiation = SSL_RENEGOTIATION_PENDING; /* Did we already try/start sending HelloRequest? */ if( ssl->out_left != 0 ) return( ssl_flush_output( ssl ) ); return( ssl_write_hello_request( ssl ) ); } #endif /* POLARSSL_SSL_SRV_C */ #if defined(POLARSSL_SSL_CLI_C) /* * On client, either start the renegotiation process or, * if already in progress, continue the handshake */ if( ssl->renegotiation != SSL_RENEGOTIATION ) { if( ssl->state != SSL_HANDSHAKE_OVER ) return( POLARSSL_ERR_SSL_BAD_INPUT_DATA ); if( ( ret = ssl_start_renegotiation( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_start_renegotiation", ret ); return( ret ); } } else { if( ( ret = ssl_handshake( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_handshake", ret ); return( ret ); } } #endif /* POLARSSL_SSL_CLI_C */ return( ret ); } /* * Receive application data decrypted from the SSL layer */ int ssl_read( ssl_context *ssl, unsigned char *buf, size_t len ) { int ret, record_read = 0; size_t n; SSL_DEBUG_MSG( 2, ( "=> read" ) ); if( ssl->state != SSL_HANDSHAKE_OVER ) { ret = ssl_handshake( ssl ); if( ret == POLARSSL_ERR_SSL_WAITING_SERVER_HELLO_RENEGO ) { record_read = 1; } else if( ret != 0 ) { SSL_DEBUG_RET( 1, "ssl_handshake", ret ); return( ret ); } } if( ssl->in_offt == NULL ) { if( ! record_read ) { if( ( ret = ssl_read_record( ssl ) ) != 0 ) { if( ret == POLARSSL_ERR_SSL_CONN_EOF ) return( 0 ); SSL_DEBUG_RET( 1, "ssl_read_record", ret ); return( ret ); } } if( ssl->in_msglen == 0 && ssl->in_msgtype == SSL_MSG_APPLICATION_DATA ) { /* * OpenSSL sends empty messages to randomize the IV */ if( ( ret = ssl_read_record( ssl ) ) != 0 ) { if( ret == POLARSSL_ERR_SSL_CONN_EOF ) return( 0 ); SSL_DEBUG_RET( 1, "ssl_read_record", ret ); return( ret ); } } if( ssl->in_msgtype == SSL_MSG_HANDSHAKE ) { SSL_DEBUG_MSG( 1, ( "received handshake message" ) ); if( ssl->endpoint == SSL_IS_CLIENT && ( ssl->in_msg[0] != SSL_HS_HELLO_REQUEST || ssl->in_hslen != 4 ) ) { SSL_DEBUG_MSG( 1, ( "handshake received (not HelloRequest)" ) ); /* With DTLS, drop the packet (probably from last handshake) */ #if defined(POLARSSL_SSL_PROTO_DTLS) if( ssl->transport == SSL_TRANSPORT_DATAGRAM ) return( POLARSSL_ERR_NET_WANT_READ ); #endif return( POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE ); } if( ssl->endpoint == SSL_IS_SERVER && ssl->in_msg[0] != SSL_HS_CLIENT_HELLO ) { SSL_DEBUG_MSG( 1, ( "handshake received (not ClientHello)" ) ); /* With DTLS, drop the packet (probably from last handshake) */ #if defined(POLARSSL_SSL_PROTO_DTLS) if( ssl->transport == SSL_TRANSPORT_DATAGRAM ) return( POLARSSL_ERR_NET_WANT_READ ); #endif return( POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE ); } if( ssl->disable_renegotiation == SSL_RENEGOTIATION_DISABLED || ( ssl->secure_renegotiation == SSL_LEGACY_RENEGOTIATION && ssl->allow_legacy_renegotiation == SSL_LEGACY_NO_RENEGOTIATION ) ) { SSL_DEBUG_MSG( 3, ( "refusing renegotiation, sending alert" ) ); #if defined(POLARSSL_SSL_PROTO_SSL3) if( ssl->minor_ver == SSL_MINOR_VERSION_0 ) { /* * SSLv3 does not have a "no_renegotiation" alert */ if( ( ret = ssl_send_fatal_handshake_failure( ssl ) ) != 0 ) return( ret ); } else #endif /* POLARSSL_SSL_PROTO_SSL3 */ #if defined(POLARSSL_SSL_PROTO_TLS1) || defined(POLARSSL_SSL_PROTO_TLS1_1) || \ defined(POLARSSL_SSL_PROTO_TLS1_2) if( ssl->minor_ver >= SSL_MINOR_VERSION_1 ) { if( ( ret = ssl_send_alert_message( ssl, SSL_ALERT_LEVEL_WARNING, SSL_ALERT_MSG_NO_RENEGOTIATION ) ) != 0 ) { return( ret ); } } else #endif /* POLARSSL_SSL_PROTO_TLS1 || POLARSSL_SSL_PROTO_TLS1_1 || POLARSSL_SSL_PROTO_TLS1_2 */ { SSL_DEBUG_MSG( 1, ( "should never happen" ) ); return( POLARSSL_ERR_SSL_INTERNAL_ERROR ); } } else { #if defined(POLARSSL_SSL_PROTO_DTLS) /* DTLS clients need to know renego is server-initiated */ if( ssl->transport == SSL_TRANSPORT_DATAGRAM && ssl->endpoint == SSL_IS_CLIENT ) { ssl->renegotiation = SSL_RENEGOTIATION_PENDING; } #endif ret = ssl_start_renegotiation( ssl ); if( ret == POLARSSL_ERR_SSL_WAITING_SERVER_HELLO_RENEGO ) { record_read = 1; } else if( ret != 0 ) { SSL_DEBUG_RET( 1, "ssl_start_renegotiation", ret ); return( ret ); } } /* If a non-handshake record was read during renego, fallthrough, * else tell the user they should call ssl_read() again */ if( ! record_read ) return( POLARSSL_ERR_NET_WANT_READ ); } else if( ssl->renegotiation == SSL_RENEGOTIATION_PENDING ) { ssl->renego_records_seen++; if( ssl->renego_max_records >= 0 && ssl->renego_records_seen > ssl->renego_max_records ) { SSL_DEBUG_MSG( 1, ( "renegotiation requested, " "but not honored by client" ) ); return( POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE ); } } /* Fatal and closure alerts handled by ssl_read_record() */ if( ssl->in_msgtype == SSL_MSG_ALERT ) { SSL_DEBUG_MSG( 2, ( "ignoring non-fatal non-closure alert" ) ); return( POLARSSL_ERR_NET_WANT_READ ); } if( ssl->in_msgtype != SSL_MSG_APPLICATION_DATA ) { SSL_DEBUG_MSG( 1, ( "bad application data message" ) ); return( POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE ); } ssl->in_offt = ssl->in_msg; } n = ( len < ssl->in_msglen ) ? len : ssl->in_msglen; memcpy( buf, ssl->in_offt, n ); ssl->in_msglen -= n; if( ssl->in_msglen == 0 ) /* all bytes consumed */ ssl->in_offt = NULL; else /* more data available */ ssl->in_offt += n; SSL_DEBUG_MSG( 2, ( "<= read" ) ); return( (int) n ); } /* * Send application data to be encrypted by the SSL layer */ int ssl_write( ssl_context *ssl, const unsigned char *buf, size_t len ) { int ret; size_t n; unsigned int max_len = SSL_MAX_CONTENT_LEN; SSL_DEBUG_MSG( 2, ( "=> write" ) ); if( ssl->state != SSL_HANDSHAKE_OVER ) { if( ( ret = ssl_handshake( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_handshake", ret ); return( ret ); } } #if defined(POLARSSL_SSL_MAX_FRAGMENT_LENGTH) /* * Assume mfl_code is correct since it was checked when set */ max_len = mfl_code_to_length[ssl->mfl_code]; /* * Check if a smaller max length was negotiated */ if( ssl->session_out != NULL && mfl_code_to_length[ssl->session_out->mfl_code] < max_len ) { max_len = mfl_code_to_length[ssl->session_out->mfl_code]; } #endif /* POLARSSL_SSL_MAX_FRAGMENT_LENGTH */ n = ( len < max_len) ? len : max_len; if( ssl->out_left != 0 ) { if( ( ret = ssl_flush_output( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_flush_output", ret ); return( ret ); } } else { ssl->out_msglen = n; ssl->out_msgtype = SSL_MSG_APPLICATION_DATA; memcpy( ssl->out_msg, buf, n ); if( ( ret = ssl_write_record( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_write_record", ret ); return( ret ); } } SSL_DEBUG_MSG( 2, ( "<= write" ) ); return( (int) n ); } /* * Notify the peer that the connection is being closed */ int ssl_close_notify( ssl_context *ssl ) { int ret; SSL_DEBUG_MSG( 2, ( "=> write close notify" ) ); if( ssl->out_left != 0 ) return( ssl_flush_output( ssl ) ); if( ssl->state == SSL_HANDSHAKE_OVER ) { if( ( ret = ssl_send_alert_message( ssl, SSL_ALERT_LEVEL_WARNING, SSL_ALERT_MSG_CLOSE_NOTIFY ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_send_alert_message", ret ); return( ret ); } } SSL_DEBUG_MSG( 2, ( "<= write close notify" ) ); return( 0 ); } void ssl_transform_free( ssl_transform *transform ) { if( transform == NULL ) return; #if defined(POLARSSL_ZLIB_SUPPORT) deflateEnd( &transform->ctx_deflate ); inflateEnd( &transform->ctx_inflate ); #endif cipher_free( &transform->cipher_ctx_enc ); cipher_free( &transform->cipher_ctx_dec ); md_free( &transform->md_ctx_enc ); md_free( &transform->md_ctx_dec ); polarssl_zeroize( transform, sizeof( ssl_transform ) ); } #if defined(POLARSSL_X509_CRT_PARSE_C) static void ssl_key_cert_free( ssl_key_cert *key_cert ) { ssl_key_cert *cur = key_cert, *next; while( cur != NULL ) { next = cur->next; if( cur->key_own_alloc ) { pk_free( cur->key ); polarssl_free( cur->key ); } polarssl_free( cur ); cur = next; } } #endif /* POLARSSL_X509_CRT_PARSE_C */ void ssl_handshake_free( ssl_handshake_params *handshake ) { if( handshake == NULL ) return; #if defined(POLARSSL_DHM_C) dhm_free( &handshake->dhm_ctx ); #endif #if defined(POLARSSL_ECDH_C) ecdh_free( &handshake->ecdh_ctx ); #endif #if defined(POLARSSL_ECDH_C) || defined(POLARSSL_ECDSA_C) /* explicit void pointer cast for buggy MS compiler */ polarssl_free( (void *) handshake->curves ); #endif #if defined(POLARSSL_X509_CRT_PARSE_C) && \ defined(POLARSSL_SSL_SERVER_NAME_INDICATION) /* * Free only the linked list wrapper, not the keys themselves * since the belong to the SNI callback */ if( handshake->sni_key_cert != NULL ) { ssl_key_cert *cur = handshake->sni_key_cert, *next; while( cur != NULL ) { next = cur->next; polarssl_free( cur ); cur = next; } } #endif /* POLARSSL_X509_CRT_PARSE_C && POLARSSL_SSL_SERVER_NAME_INDICATION */ #if defined(POLARSSL_SSL_PROTO_DTLS) polarssl_free( handshake->verify_cookie ); polarssl_free( handshake->hs_msg ); #endif polarssl_zeroize( handshake, sizeof( ssl_handshake_params ) ); } void ssl_session_free( ssl_session *session ) { if( session == NULL ) return; #if defined(POLARSSL_X509_CRT_PARSE_C) if( session->peer_cert != NULL ) { x509_crt_free( session->peer_cert ); polarssl_free( session->peer_cert ); } #endif #if defined(POLARSSL_SSL_SESSION_TICKETS) polarssl_free( session->ticket ); #endif polarssl_zeroize( session, sizeof( ssl_session ) ); } /* * Free an SSL context */ void ssl_free( ssl_context *ssl ) { if( ssl == NULL ) return; SSL_DEBUG_MSG( 2, ( "=> free" ) ); if( ssl->out_buf != NULL ) { polarssl_zeroize( ssl->out_buf, SSL_BUFFER_LEN ); polarssl_free( ssl->out_buf ); } if( ssl->in_buf != NULL ) { polarssl_zeroize( ssl->in_buf, SSL_BUFFER_LEN ); polarssl_free( ssl->in_buf ); } #if defined(POLARSSL_ZLIB_SUPPORT) if( ssl->compress_buf != NULL ) { polarssl_zeroize( ssl->compress_buf, SSL_BUFFER_LEN ); polarssl_free( ssl->compress_buf ); } #endif #if defined(POLARSSL_DHM_C) mpi_free( &ssl->dhm_P ); mpi_free( &ssl->dhm_G ); #endif if( ssl->transform ) { ssl_transform_free( ssl->transform ); polarssl_free( ssl->transform ); } if( ssl->handshake ) { ssl_handshake_free( ssl->handshake ); ssl_transform_free( ssl->transform_negotiate ); ssl_session_free( ssl->session_negotiate ); polarssl_free( ssl->handshake ); polarssl_free( ssl->transform_negotiate ); polarssl_free( ssl->session_negotiate ); } if( ssl->session ) { ssl_session_free( ssl->session ); polarssl_free( ssl->session ); } #if defined(POLARSSL_SSL_SESSION_TICKETS) if( ssl->ticket_keys ) { ssl_ticket_keys_free( ssl->ticket_keys ); polarssl_free( ssl->ticket_keys ); } #endif #if defined(POLARSSL_SSL_SERVER_NAME_INDICATION) if( ssl->hostname != NULL ) { polarssl_zeroize( ssl->hostname, ssl->hostname_len ); polarssl_free( ssl->hostname ); ssl->hostname_len = 0; } #endif #if defined(POLARSSL_KEY_EXCHANGE__SOME__PSK_ENABLED) if( ssl->psk != NULL ) { polarssl_zeroize( ssl->psk, ssl->psk_len ); polarssl_zeroize( ssl->psk_identity, ssl->psk_identity_len ); polarssl_free( ssl->psk ); polarssl_free( ssl->psk_identity ); ssl->psk_len = 0; ssl->psk_identity_len = 0; } #endif #if defined(POLARSSL_X509_CRT_PARSE_C) ssl_key_cert_free( ssl->key_cert ); #endif #if defined(POLARSSL_SSL_HW_RECORD_ACCEL) if( ssl_hw_record_finish != NULL ) { SSL_DEBUG_MSG( 2, ( "going for ssl_hw_record_finish()" ) ); ssl_hw_record_finish( ssl ); } #endif #if defined(POLARSSL_SSL_DTLS_HELLO_VERIFY) polarssl_free( ssl->cli_id ); #endif SSL_DEBUG_MSG( 2, ( "<= free" ) ); /* Actually clear after last debug message */ polarssl_zeroize( ssl, sizeof( ssl_context ) ); } #if defined(POLARSSL_PK_C) /* * Convert between POLARSSL_PK_XXX and SSL_SIG_XXX */ unsigned char ssl_sig_from_pk( pk_context *pk ) { #if defined(POLARSSL_RSA_C) if( pk_can_do( pk, POLARSSL_PK_RSA ) ) return( SSL_SIG_RSA ); #endif #if defined(POLARSSL_ECDSA_C) if( pk_can_do( pk, POLARSSL_PK_ECDSA ) ) return( SSL_SIG_ECDSA ); #endif return( SSL_SIG_ANON ); } pk_type_t ssl_pk_alg_from_sig( unsigned char sig ) { switch( sig ) { #if defined(POLARSSL_RSA_C) case SSL_SIG_RSA: return( POLARSSL_PK_RSA ); #endif #if defined(POLARSSL_ECDSA_C) case SSL_SIG_ECDSA: return( POLARSSL_PK_ECDSA ); #endif default: return( POLARSSL_PK_NONE ); } } #endif /* POLARSSL_PK_C */ /* * Convert between SSL_HASH_XXX and POLARSSL_MD_XXX */ md_type_t ssl_md_alg_from_hash( unsigned char hash ) { switch( hash ) { #if defined(POLARSSL_MD5_C) case SSL_HASH_MD5: return( POLARSSL_MD_MD5 ); #endif #if defined(POLARSSL_SHA1_C) case SSL_HASH_SHA1: return( POLARSSL_MD_SHA1 ); #endif #if defined(POLARSSL_SHA256_C) case SSL_HASH_SHA224: return( POLARSSL_MD_SHA224 ); case SSL_HASH_SHA256: return( POLARSSL_MD_SHA256 ); #endif #if defined(POLARSSL_SHA512_C) case SSL_HASH_SHA384: return( POLARSSL_MD_SHA384 ); case SSL_HASH_SHA512: return( POLARSSL_MD_SHA512 ); #endif default: return( POLARSSL_MD_NONE ); } } #if defined(POLARSSL_SSL_SET_CURVES) /* * Check is a curve proposed by the peer is in our list. * Return 1 if we're willing to use it, 0 otherwise. */ int ssl_curve_is_acceptable( const ssl_context *ssl, ecp_group_id grp_id ) { const ecp_group_id *gid; for( gid = ssl->curve_list; *gid != POLARSSL_ECP_DP_NONE; gid++ ) if( *gid == grp_id ) return( 1 ); return( 0 ); } #endif /* POLARSSL_SSL_SET_CURVES */ #if defined(POLARSSL_X509_CRT_PARSE_C) int ssl_check_cert_usage( const x509_crt *cert, const ssl_ciphersuite_t *ciphersuite, int cert_endpoint ) { #if defined(POLARSSL_X509_CHECK_KEY_USAGE) int usage = 0; #endif #if defined(POLARSSL_X509_CHECK_EXTENDED_KEY_USAGE) const char *ext_oid; size_t ext_len; #endif #if !defined(POLARSSL_X509_CHECK_KEY_USAGE) && \ !defined(POLARSSL_X509_CHECK_EXTENDED_KEY_USAGE) ((void) cert); ((void) cert_endpoint); #endif #if defined(POLARSSL_X509_CHECK_KEY_USAGE) if( cert_endpoint == SSL_IS_SERVER ) { /* Server part of the key exchange */ switch( ciphersuite->key_exchange ) { case POLARSSL_KEY_EXCHANGE_RSA: case POLARSSL_KEY_EXCHANGE_RSA_PSK: usage = KU_KEY_ENCIPHERMENT; break; case POLARSSL_KEY_EXCHANGE_DHE_RSA: case POLARSSL_KEY_EXCHANGE_ECDHE_RSA: case POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA: usage = KU_DIGITAL_SIGNATURE; break; case POLARSSL_KEY_EXCHANGE_ECDH_RSA: case POLARSSL_KEY_EXCHANGE_ECDH_ECDSA: usage = KU_KEY_AGREEMENT; break; /* Don't use default: we want warnings when adding new values */ case POLARSSL_KEY_EXCHANGE_NONE: case POLARSSL_KEY_EXCHANGE_PSK: case POLARSSL_KEY_EXCHANGE_DHE_PSK: case POLARSSL_KEY_EXCHANGE_ECDHE_PSK: usage = 0; } } else { /* Client auth: we only implement rsa_sign and ecdsa_sign for now */ usage = KU_DIGITAL_SIGNATURE; } if( x509_crt_check_key_usage( cert, usage ) != 0 ) return( -1 ); #else ((void) ciphersuite); #endif /* POLARSSL_X509_CHECK_KEY_USAGE */ #if defined(POLARSSL_X509_CHECK_EXTENDED_KEY_USAGE) if( cert_endpoint == SSL_IS_SERVER ) { ext_oid = OID_SERVER_AUTH; ext_len = OID_SIZE( OID_SERVER_AUTH ); } else { ext_oid = OID_CLIENT_AUTH; ext_len = OID_SIZE( OID_CLIENT_AUTH ); } if( x509_crt_check_extended_key_usage( cert, ext_oid, ext_len ) != 0 ) return( -1 ); #endif /* POLARSSL_X509_CHECK_EXTENDED_KEY_USAGE */ return( 0 ); } #endif /* POLARSSL_X509_CRT_PARSE_C */ /* * Convert version numbers to/from wire format * and, for DTLS, to/from TLS equivalent. * * For TLS this is the identity. * For DTLS, use one complement (v -> 255 - v, and then map as follows: * 1.0 <-> 3.2 (DTLS 1.0 is based on TLS 1.1) * 1.x <-> 3.x+1 for x != 0 (DTLS 1.2 based on TLS 1.2) */ void ssl_write_version( int major, int minor, int transport, unsigned char ver[2] ) { #if defined(POLARSSL_SSL_PROTO_DTLS) if( transport == SSL_TRANSPORT_DATAGRAM ) { if( minor == SSL_MINOR_VERSION_2 ) --minor; /* DTLS 1.0 stored as TLS 1.1 internally */ ver[0] = (unsigned char)( 255 - ( major - 2 ) ); ver[1] = (unsigned char)( 255 - ( minor - 1 ) ); } else #else ((void) transport); #endif { ver[0] = (unsigned char) major; ver[1] = (unsigned char) minor; } } void ssl_read_version( int *major, int *minor, int transport, const unsigned char ver[2] ) { #if defined(POLARSSL_SSL_PROTO_DTLS) if( transport == SSL_TRANSPORT_DATAGRAM ) { *major = 255 - ver[0] + 2; *minor = 255 - ver[1] + 1; if( *minor == SSL_MINOR_VERSION_1 ) ++*minor; /* DTLS 1.0 stored as TLS 1.1 internally */ } else #else ((void) transport); #endif { *major = ver[0]; *minor = ver[1]; } } #endif /* POLARSSL_SSL_TLS_C */