diff --git a/programs/.gitignore b/programs/.gitignore index 72ccb5bd4..a4ff337f4 100644 --- a/programs/.gitignore +++ b/programs/.gitignore @@ -38,6 +38,7 @@ pkey/rsa_sign pkey/rsa_sign_pss pkey/rsa_verify pkey/rsa_verify_pss +psa/aead_cipher_psa psa/crypto_examples psa/hmac_md_psa psa/key_ladder_demo diff --git a/programs/Makefile b/programs/Makefile index 782cf9050..62654a5a1 100644 --- a/programs/Makefile +++ b/programs/Makefile @@ -84,6 +84,7 @@ APPS = \ pkey/rsa_sign_pss \ pkey/rsa_verify \ pkey/rsa_verify_pss \ + psa/aead_cipher_psa \ psa/crypto_examples \ psa/hmac_md_psa \ psa/key_ladder_demo \ @@ -262,6 +263,10 @@ pkey/rsa_encrypt$(EXEXT): pkey/rsa_encrypt.c $(DEP) echo " CC pkey/rsa_encrypt.c" $(CC) $(LOCAL_CFLAGS) $(CFLAGS) pkey/rsa_encrypt.c $(LOCAL_LDFLAGS) $(LDFLAGS) -o $@ +psa/aead_cipher_psa$(EXEXT): psa/aead_cipher_psa.c $(DEP) + echo " CC psa/aead_cipher_psa.c" + $(CC) $(LOCAL_CFLAGS) $(CFLAGS) psa/aead_cipher_psa.c $(LOCAL_LDFLAGS) $(LDFLAGS) -o $@ + psa/crypto_examples$(EXEXT): psa/crypto_examples.c $(DEP) echo " CC psa/crypto_examples.c" $(CC) $(LOCAL_CFLAGS) $(CFLAGS) psa/crypto_examples.c $(LOCAL_LDFLAGS) $(LDFLAGS) -o $@ diff --git a/programs/psa/CMakeLists.txt b/programs/psa/CMakeLists.txt index 27732308c..450ef3668 100644 --- a/programs/psa/CMakeLists.txt +++ b/programs/psa/CMakeLists.txt @@ -1,4 +1,5 @@ set(executables + aead_cipher_psa crypto_examples hmac_md_psa key_ladder_demo diff --git a/programs/psa/aead_cipher_psa.c b/programs/psa/aead_cipher_psa.c new file mode 100644 index 000000000..301701c18 --- /dev/null +++ b/programs/psa/aead_cipher_psa.c @@ -0,0 +1,350 @@ +/* + * Copyright The Mbed TLS Contributors + * SPDX-License-Identifier: Apache-2.0 + * + * Licensed under the Apache License, Version 2.0 (the "License"); you may + * not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT + * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +/* + * This is a simple example of multi-part AEAD computation using both the old + * Cipher API and the new PSA API; its goal is to help migration to PSA Crypto. + * + * When in comes to multi-part HMAC operations, the `mbedtls_md_context` + * serves a triple purpose (1) hold the key, (2) store the algorithm, and (3) + * save progress information for the current operation. With PSA those roles + * are held by disinct objects: (1) a psa_key_id_t to hold the key, a (2) + * psa_algorithm_t to represent the algorithm, and (3) a psa_operation_t for + * multi-part progress. + * + * On the other hand, with PSA, the algorithms encodes the desired tag length; + * with Cipher the desired tag length needs to be tracked separately. + * + * This program illustrates this by doing the same sequence of multi-part AEAD + * computation with both APIs; looking at the two series of functions + * cipher_xxx() and aead_xxx() side by side should make the differences and + * similarities clear. + */ + +#include + +#include "mbedtls/build_info.h" + +#if !defined(MBEDTLS_PSA_CRYPTO_C) || !defined(MBEDTLS_CIPHER_C) || \ + !defined(MBEDTLS_AES_C) || !defined(MBEDTLS_GCM_C) || \ + !defined(MBEDTLS_CHACHAPOLY_C) +int main( void ) +{ + printf( "MBEDTLS_PSA_CRYPTO_C and/or MBEDTLS_MD_C and/or " + "MBEDTLS_AES_C and/or MBEDTLS_GCM_C and/or " + "MBEDTLS_CHACHAPOLY_C not defined.\r\n" ); + return( 0 ); +} +#else + +#include + +#include "mbedtls/cipher.h" +#include "psa/crypto.h" + +/* + * Common data and helper functions + */ +const char usage[] = "Usage: aead_cipher_psa [gcm128|gcm256|gcm128_8|chachapoly]"; + +const unsigned char iv1[12] = { 0x00 }; +const unsigned char ad1[] = { 0x01, 0x02 }; +const unsigned char pa1[] = { 0x03, 0x04 }; +const unsigned char pb1[] = { 0x05, 0x06, 0x07 }; + +const unsigned char iv2[12] = { 0x10 }; +const unsigned char ad2[] = { 0x11, 0x12 }; +const unsigned char pa2[] = { 0x13, 0x14 }; +const unsigned char pb2[] = { 0x15, 0x16, 0x17 }; + +const unsigned char key_bytes[32] = { 0x2a }; + +void print_out( const char *title, unsigned char *out, size_t len ) +{ + printf( "%s:", title ); + for( size_t i = 0; i < len; i++ ) + printf( " %02x", out[i] ); + printf( "\n" ); +} + +/* + * Functions using the Cipher API + */ +#define CHK( code ) \ + do { \ + ret = code; \ + if( ret != 0 ) { \ + printf( "%s:%03d: ret = -0x%04x\n", __func__, __LINE__, -ret ); \ + goto exit; \ + } \ + } while( 0 ) + + +static int cipher_prepare( const char *info, + mbedtls_cipher_context_t *ctx, + size_t *tag_len ) +{ + int ret; + + mbedtls_cipher_type_t type; + if( strcmp( info, "gcm128" ) == 0 ) { + type = MBEDTLS_CIPHER_AES_128_GCM; + *tag_len = 16; + } else if( strcmp( info, "gcm256" ) == 0 ) { + type = MBEDTLS_CIPHER_AES_256_GCM; + *tag_len = 16; + } else if( strcmp( info, "gcm128_8" ) == 0 ) { + type = MBEDTLS_CIPHER_AES_128_GCM; + *tag_len = 8; + } else if( strcmp( info, "chachapoly" ) == 0 ) { + type = MBEDTLS_CIPHER_CHACHA20_POLY1305; + *tag_len = 16; + } else { + puts( usage ); + return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA ); + } + + CHK( mbedtls_cipher_setup( ctx, + mbedtls_cipher_info_from_type( type ) ) ); + + size_t key_len = mbedtls_cipher_get_key_bitlen( ctx ); + CHK( mbedtls_cipher_setkey( ctx, key_bytes, key_len, MBEDTLS_ENCRYPT ) ); + +exit: + return( ret ); +} + +static void cipher_info( const mbedtls_cipher_context_t *ctx, size_t tag_len ) +{ + // no convenient way to get the cipher type (for example, AES) + const char *ciph = "???"; + int key_bits = mbedtls_cipher_get_key_bitlen( ctx ); + mbedtls_cipher_mode_t mode = mbedtls_cipher_get_cipher_mode( ctx ); + + const char *mode_str = mode == MBEDTLS_MODE_GCM ? "GCM" + : mode == MBEDTLS_MODE_CHACHAPOLY ? "ChachaPoly" + : "???"; + + printf( "cipher: %s, %d, %s, %zu\n", ciph, key_bits, mode_str, tag_len ); +} + +static int cipher_encrypt( mbedtls_cipher_context_t *ctx, size_t tag_len, + const unsigned char *iv, size_t iv_len, + const unsigned char *ad, size_t ad_len, + const unsigned char *pa, size_t pa_len, + const unsigned char *pb, size_t pb_len ) +{ + int ret; + size_t olen; + unsigned char out[32]; + unsigned char *p = out; + + CHK( mbedtls_cipher_set_iv( ctx, iv, iv_len ) ); + CHK( mbedtls_cipher_reset( ctx ) ); + CHK( mbedtls_cipher_update_ad( ctx, ad, ad_len ) ); + CHK( mbedtls_cipher_update( ctx, pa, pa_len, p, &olen ) ); + p += olen; + CHK( mbedtls_cipher_update( ctx, pb, pb_len, p, &olen ) ); + p += olen; + CHK( mbedtls_cipher_finish( ctx, p, &olen ) ); + p += olen; + CHK( mbedtls_cipher_write_tag( ctx, p, tag_len ) ); + p += tag_len; + + olen = p - out; + print_out( "cipher", out, olen ); + +exit: + return( ret ); +} + +static int cipher( const char *info ) +{ + int ret = 0; + + mbedtls_cipher_context_t ctx; + size_t tag_len; + + mbedtls_cipher_init( &ctx ); + + CHK( cipher_prepare( info, &ctx, &tag_len ) ); + + cipher_info( &ctx, tag_len ); + + CHK( cipher_encrypt( &ctx, tag_len, + iv1, sizeof( iv1 ), ad1, sizeof( ad1 ), + pa1, sizeof( pa1 ), pb1, sizeof( pb1 ) ) ); + CHK( cipher_encrypt( &ctx, tag_len, + iv2, sizeof( iv2 ), ad2, sizeof( ad2 ), + pa2, sizeof( pa2 ), pb2, sizeof( pb2 ) ) ); + +exit: + mbedtls_cipher_free( &ctx ); + + return( ret ); +} + +#undef CHK + +/* + * Functions using the PSA Crypto API + */ + +#define CHK( code ) \ + do { \ + status = code; \ + if( status != PSA_SUCCESS ) { \ + printf( "%s:%03d: status = %d\n", __func__, __LINE__, status ); \ + goto exit; \ + } \ + } while( 0 ) + +static psa_status_t aead_prepare( const char *info, + psa_key_id_t *key, + psa_algorithm_t *alg ) +{ + psa_status_t status; + + size_t key_bits; + psa_key_type_t key_type; + if( strcmp( info, "gcm128" ) == 0 ) { + *alg = PSA_ALG_GCM; + key_bits = 128; + key_type = PSA_KEY_TYPE_AES; + } else if( strcmp( info, "gcm256" ) == 0 ) { + *alg = PSA_ALG_GCM; + key_bits = 256; + key_type = PSA_KEY_TYPE_AES; + } else if( strcmp( info, "gcm128_8" ) == 0 ) { + *alg = PSA_ALG_AEAD_WITH_SHORTENED_TAG(PSA_ALG_GCM, 8); + key_bits = 128; + key_type = PSA_KEY_TYPE_AES; + } else if( strcmp( info, "chachapoly" ) == 0 ) { + *alg = PSA_ALG_CHACHA20_POLY1305; + key_bits = 256; + key_type = PSA_KEY_TYPE_CHACHA20; + } else { + puts( usage ); + return( PSA_ERROR_INVALID_ARGUMENT ); + } + + psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT; + psa_set_key_usage_flags( &attributes, PSA_KEY_USAGE_ENCRYPT ); + psa_set_key_algorithm( &attributes, *alg ); + psa_set_key_type( &attributes, key_type ); + psa_set_key_bits( &attributes, key_bits ); + + CHK( psa_import_key( &attributes, key_bytes, key_bits / 8, key ) ); + +exit: + return( status ); +} + +static void aead_info( psa_key_id_t key, psa_algorithm_t alg ) +{ + psa_key_attributes_t attr = PSA_KEY_ATTRIBUTES_INIT; + (void) psa_get_key_attributes( key, &attr ); + psa_key_type_t key_type = psa_get_key_type( &attr ); + size_t key_bits = psa_get_key_bits( &attr ); + psa_algorithm_t base_alg = PSA_ALG_AEAD_WITH_DEFAULT_LENGTH_TAG( alg ); + size_t tag_len = PSA_AEAD_TAG_LENGTH( key_type, key_bits, alg ); + + const char *type_str = key_type == PSA_KEY_TYPE_AES ? "AES" + : key_type == PSA_KEY_TYPE_CHACHA20 ? "Chacha" + : "???"; + const char *base_str = base_alg == PSA_ALG_GCM ? "GCM" + : base_alg == PSA_ALG_CHACHA20_POLY1305 ? "ChachaPoly" + : "???"; + + printf( "aead : %s, %zu, %s, %zu\n", type_str, key_bits, base_str, tag_len ); +} + +static int aead_encrypt( psa_key_id_t key, psa_algorithm_t alg, + const unsigned char *iv, size_t iv_len, + const unsigned char *ad, size_t ad_len, + const unsigned char *pa, size_t pa_len, + const unsigned char *pb, size_t pb_len ) +{ + psa_status_t status; + size_t olen, olen_tag; + unsigned char out[32]; + unsigned char *p = out, *end = out + sizeof( out ); + unsigned char tag[16]; + + psa_aead_operation_t op = PSA_AEAD_OPERATION_INIT; + CHK( psa_aead_encrypt_setup( &op, key, alg ) ); + + CHK( psa_aead_set_nonce( &op, iv, iv_len ) ); + CHK( psa_aead_update_ad( &op, ad, ad_len ) ); + CHK( psa_aead_update( &op, pa, pa_len, p, end - p, &olen ) ); + p += olen; + CHK( psa_aead_update( &op, pb, pb_len, p, end - p, &olen ) ); + p += olen; + CHK( psa_aead_finish( &op, p, end - p, &olen, + tag, sizeof( tag ), &olen_tag ) ); + p += olen; + memcpy( p, tag, olen_tag ); + p += olen_tag; + + olen = p - out; + print_out( "aead ", out, olen ); +exit: + return( status ); +} + +static psa_status_t aead( const char *info ) +{ + psa_status_t status; + + psa_key_id_t key; + psa_algorithm_t alg; + + CHK( aead_prepare( info, &key, &alg ) ); + + aead_info( key, alg ); + + CHK( aead_encrypt( key, alg, + iv1, sizeof( iv1 ), ad1, sizeof( ad1 ), + pa1, sizeof( pa1 ), pb1, sizeof( pb1 ) ) ); + CHK( aead_encrypt( key, alg, + iv2, sizeof( iv2 ), ad2, sizeof( ad2 ), + pa2, sizeof( pa2 ), pb2, sizeof( pb2 ) ) ); + +exit: + return( status ); +} + +#undef CHK + +/* + * Main function + */ +int main( int argc, char **argv ) +{ + if( argc != 2 ) + { + puts( usage ); + return( 1 ); + } + + psa_crypto_init(); + + cipher( argv[1] ); + aead( argv[1] ); +} + +#endif