Extend mbedtls_ssl_session by buffer holding peer CRT digest

This commit is contained in:
Hanno Becker 2019-02-05 17:00:50 +00:00
parent 8d84fd83ff
commit 9198ad1101
2 changed files with 51 additions and 1 deletions

View File

@ -787,6 +787,22 @@ typedef int mbedtls_ssl_async_resume_t( mbedtls_ssl_context *ssl,
typedef void mbedtls_ssl_async_cancel_t( mbedtls_ssl_context *ssl );
#endif /* MBEDTLS_SSL_ASYNC_PRIVATE */
#if defined(MBEDTLS_X509_CRT_PARSE_C)
#define MBEDTLS_SSL_PEER_CERT_DIGEST_MAX_LEN 48
#if defined(MBEDTLS_SHA256_C)
#define MBEDTLS_SSL_PEER_CERT_DIGEST_DFL_TYPE MBEDTLS_MD_SHA256
#define MBEDTLS_SSL_PEER_CERT_DIGEST_DFL_LEN 32
#elif defined(MBEDTLS_SHA512_C)
#define MBEDTLS_SSL_PEER_CERT_DIGEST_DFL_TYPE MBEDTLS_MD_SHA384
#define MBEDTLS_SSL_PEER_CERT_DIGEST_DFL_LEN 48
#elif defined(MBEDTLS_SHA1_C)
#define MBEDTLS_SSL_PEER_CERT_DIGEST_DFL_TYPE MBEDTLS_MD_SHA1
#define MBEDTLS_SSL_PEER_CERT_DIGEST_DFL_LEN 20
#else
#error "Bad configuration - need SHA-1, SHA-256 or SHA-512 enabled to compute digest of peer CRT."
#endif
#endif /* MBEDTLS_X509_CRT_PARSE_C */
/*
* This structure is used for storing current session data.
*/
@ -802,7 +818,14 @@ struct mbedtls_ssl_session
unsigned char master[48]; /*!< the master secret */
#if defined(MBEDTLS_X509_CRT_PARSE_C)
mbedtls_x509_crt *peer_cert; /*!< peer X.509 cert chain */
mbedtls_x509_crt *peer_cert; /*!< peer X.509 cert chain */
#if !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
/*! The digest of the peer's end-CRT. This must be kept to detect CRT
* changes during renegotiation, mitigating the triple handshake attack. */
unsigned char *peer_cert_digest;
size_t peer_cert_digest_len;
mbedtls_md_type_t peer_cert_digest_type;
#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
#endif /* MBEDTLS_X509_CRT_PARSE_C */
uint32_t verify_result; /*!< verification result */

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@ -304,6 +304,22 @@ int mbedtls_ssl_session_copy( mbedtls_ssl_session *dst,
return( ret );
}
}
#if !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
if( src->peer_cert_digest != NULL )
{
dst->peer_cert_digest_len = src->peer_cert_digest_len;
dst->peer_cert_digest =
mbedtls_calloc( 1, dst->peer_cert_digest_len );
if( dst->peer_cert_digest == NULL )
return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
memcpy( dst->peer_cert_digest, src->peer_cert_digest,
src->peer_cert_digest_len );
dst->peer_cert_digest_type = src->peer_cert_digest_type;
}
#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
#endif /* MBEDTLS_X509_CRT_PARSE_C */
#if defined(MBEDTLS_SSL_SESSION_TICKETS) && defined(MBEDTLS_SSL_CLI_C)
@ -5733,6 +5749,17 @@ static void ssl_clear_peer_cert( mbedtls_ssl_session *session )
mbedtls_free( session->peer_cert );
session->peer_cert = NULL;
}
#if !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
if( session->peer_cert_digest != NULL )
{
/* Zeroization is not necessary. */
mbedtls_free( session->peer_cert_digest );
session->peer_cert_digest = NULL;
session->peer_cert_digest_type = MBEDTLS_MD_NONE;
session->peer_cert_digest_len = 0;
}
#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
}
/*