From 6db455e6e35e70336471b3470f471a3cc16c097a Mon Sep 17 00:00:00 2001 From: Paul Bakker Date: Wed, 18 Sep 2013 17:29:31 +0200 Subject: [PATCH] PSK callback added to SSL server --- include/polarssl/error.h | 2 +- include/polarssl/ssl.h | 45 +++++++++++++++++++++++++++++----- library/error.c | 4 +++- library/ssl_srv.c | 34 +++++++++++++++++++++----- library/ssl_tls.c | 52 ++++++++++++++++++++++++++++++++-------- 5 files changed, 113 insertions(+), 24 deletions(-) diff --git a/include/polarssl/error.h b/include/polarssl/error.h index bc3fb1103..4cf4ec97d 100644 --- a/include/polarssl/error.h +++ b/include/polarssl/error.h @@ -84,7 +84,7 @@ * ECP 4 7 (Started from top) * MD 5 4 * CIPHER 6 5 - * SSL 6 6 (Started from top) + * SSL 6 7 (Started from top) * SSL 7 31 * * Module dependent error code (5 bits 0x.08.-0x.F8.) diff --git a/include/polarssl/ssl.h b/include/polarssl/ssl.h index 7c9098787..fa313f41f 100644 --- a/include/polarssl/ssl.h +++ b/include/polarssl/ssl.h @@ -126,6 +126,7 @@ #define POLARSSL_ERR_SSL_BAD_HS_NEW_SESSION_TICKET -0x6E00 /**< Processing of the NewSessionTicket handshake message failed. */ #define POLARSSL_ERR_SSL_SESSION_TICKET_EXPIRED -0x6D80 /**< Session ticket has expired. */ #define POLARSSL_ERR_SSL_PK_TYPE_MISMATCH -0x6D00 /**< Public key type mismatch (eg, asked for RSA key exchange and presented EC key) */ +#define POLARSSL_ERR_SSL_UNKNOWN_IDENTITY -0x6C80 /**< Unkown identity received (eg, PSK identity) */ /* * Various constants @@ -588,6 +589,11 @@ struct _ssl_context void *p_vrfy; /*!< context for verification */ #endif +#if defined(POLARSSL_KEY_EXCHANGE_PSK_ENABLED) + int (*f_psk)(void *, ssl_context *, const unsigned char *, size_t); + void *p_psk; /*!< context for PSK retrieval */ +#endif + /* * Session layer */ @@ -689,9 +695,9 @@ struct _ssl_context /* * PSK values */ - const unsigned char *psk; + unsigned char *psk; size_t psk_len; - const unsigned char *psk_identity; + unsigned char *psk_identity; size_t psk_identity_len; #endif @@ -1022,16 +1028,43 @@ int ssl_set_own_cert_alt( ssl_context *ssl, x509_crt *own_cert, #if defined(POLARSSL_KEY_EXCHANGE_PSK_ENABLED) /** * \brief Set the Pre Shared Key (PSK) and the identity name connected - * to it. The PSK is used in all PSK-based ciphersuites. + * to it. * * \param ssl SSL context * \param psk pointer to the pre-shared key * \param psk_len pre-shared key length * \param psk_identity pointer to the pre-shared key identity * \param psk_identity_len identity key length + * + * \return 0 if successful or POLARSSL_ERR_SSL_MALLOC_FAILED */ -void ssl_set_psk( ssl_context *ssl, const unsigned char *psk, size_t psk_len, - const unsigned char *psk_identity, size_t psk_identity_len ); +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 ); + +/** + * \brief Set the PSK callback (server-side only) (Optional). + * + * If set, the PSK callback is called for each + * handshake where a PSK ciphersuite was negotiated. + * The callback provides the identity received and wants to + * receive the actual PSK data and length. + * + * The callback has the following parameters: (void *parameter, + * ssl_context *ssl, const unsigned char *psk_identity, + * size_t identity_len) + * If a valid PSK identity is found, the callback should use + * ssl_set_psk() on the ssl context to set the correct PSK and + * identity and return 0. + * Any other return value will result in a denied PSK identity. + * + * \param ssl SSL context + * \param f_psk PSK identity function + * \param p_psk PSK identity parameter + */ +void ssl_set_psk_cb( ssl_context *ssl, + int (*f_psk)(void *, ssl_context *, const unsigned char *, + size_t), + void *p_psk ); #endif /* POLARSSL_KEY_EXCHANGE_PSK_ENABLED */ #if defined(POLARSSL_DHM_C) @@ -1064,7 +1097,7 @@ int ssl_set_dh_param_ctx( ssl_context *ssl, dhm_context *dhm_ctx ); /** * \brief Set hostname for ServerName TLS extension * (client-side only) - * + * * * \param ssl SSL context * \param hostname the server hostname diff --git a/library/error.c b/library/error.c index 04ce28e80..f67476833 100644 --- a/library/error.c +++ b/library/error.c @@ -409,6 +409,8 @@ void polarssl_strerror( int ret, char *buf, size_t buflen ) snprintf( buf, buflen, "SSL - Session ticket has expired" ); if( use_ret == -(POLARSSL_ERR_SSL_PK_TYPE_MISMATCH) ) snprintf( buf, buflen, "SSL - Public key type mismatch (eg, asked for RSA key exchange and presented EC key)" ); + if( use_ret == -(POLARSSL_ERR_SSL_UNKNOWN_IDENTITY) ) + snprintf( buf, buflen, "SSL - Unkown identity received (eg, PSK identity)" ); #endif /* POLARSSL_SSL_TLS_C */ #if defined(POLARSSL_X509_USE_C) || defined(POLARSSL_X509_CREATE_C) @@ -437,7 +439,7 @@ void polarssl_strerror( int ret, char *buf, size_t buflen ) if( use_ret == -(POLARSSL_ERR_X509_UNKNOWN_SIG_ALG) ) snprintf( buf, buflen, "X509 - Signature algorithm (oid) is unsupported" ); if( use_ret == -(POLARSSL_ERR_X509_SIG_MISMATCH) ) - snprintf( buf, buflen, "X509 - Signature algorithms do not match. (see \\c ::x509_cert sig_oid)" ); + snprintf( buf, buflen, "X509 - Signature algorithms do not match. (see \\c ::x509_crt sig_oid)" ); if( use_ret == -(POLARSSL_ERR_X509_CERT_VERIFY_FAILED) ) snprintf( buf, buflen, "X509 - Certificate verification failed, e.g. CRL, CA or signature check failed" ); if( use_ret == -(POLARSSL_ERR_X509_CERT_UNKNOWN_FORMAT) ) diff --git a/library/ssl_srv.c b/library/ssl_srv.c index 8d1b723ba..1b48a9771 100644 --- a/library/ssl_srv.c +++ b/library/ssl_srv.c @@ -2286,11 +2286,12 @@ static int ssl_parse_encrypted_pms_secret( ssl_context *ssl ) static int ssl_parse_client_psk_identity( ssl_context *ssl, unsigned char **p, const unsigned char *end ) { - int ret = POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE; + int ret = 0; size_t n; - if( ssl->psk == NULL || ssl->psk_identity == NULL || - ssl->psk_identity_len == 0 || ssl->psk_len == 0 ) + if( ssl->f_psk == NULL && + ( ssl->psk == NULL || ssl->psk_identity == NULL || + ssl->psk_identity_len == 0 || ssl->psk_len == 0 ) ) { SSL_DEBUG_MSG( 1, ( "got no pre-shared key" ) ); return( POLARSSL_ERR_SSL_PRIVATE_KEY_REQUIRED ); @@ -2314,11 +2315,32 @@ static int ssl_parse_client_psk_identity( ssl_context *ssl, unsigned char **p, return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE ); } - if( n != ssl->psk_identity_len || - memcmp( ssl->psk_identity, *p, n ) != 0 ) + if( ssl->f_psk != NULL ) + { + if( ( ret != ssl->f_psk( ssl->p_psk, ssl, *p, n ) ) != 0 ) + ret = POLARSSL_ERR_SSL_UNKNOWN_IDENTITY; + } + + if( ret == 0 ) + { + if( n != ssl->psk_identity_len || + memcmp( ssl->psk_identity, *p, n ) != 0 ) + { + ret = POLARSSL_ERR_SSL_UNKNOWN_IDENTITY; + } + } + + if( ret == POLARSSL_ERR_SSL_UNKNOWN_IDENTITY ) { SSL_DEBUG_BUF( 3, "Unknown PSK identity", *p, n ); - return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE ); + if( ( ret = ssl_send_alert_message( ssl, + SSL_ALERT_LEVEL_FATAL, + SSL_ALERT_MSG_UNKNOWN_PSK_IDENTITY ) ) != 0 ) + { + return( ret ); + } + + return( POLARSSL_ERR_SSL_UNKNOWN_IDENTITY ); } *p += n; diff --git a/library/ssl_tls.c b/library/ssl_tls.c index 774cb4721..020d0e880 100644 --- a/library/ssl_tls.c +++ b/library/ssl_tls.c @@ -3242,11 +3242,6 @@ int ssl_init( ssl_context *ssl ) memset( ssl-> in_ctr, 0, SSL_BUFFER_LEN ); memset( ssl->out_ctr, 0, SSL_BUFFER_LEN ); -#if defined(POLARSSL_SSL_SERVER_NAME_INDICATION) - ssl->hostname = NULL; - ssl->hostname_len = 0; -#endif - #if defined(POLARSSL_SSL_SESSION_TICKETS) ssl->ticket_lifetime = SSL_DEFAULT_TICKET_LIFETIME; #endif @@ -3529,13 +3524,38 @@ int ssl_set_own_cert_alt( ssl_context *ssl, x509_crt *own_cert, #endif /* POLARSSL_X509_CRT_PARSE_C */ #if defined(POLARSSL_KEY_EXCHANGE_PSK_ENABLED) -void ssl_set_psk( ssl_context *ssl, const unsigned char *psk, size_t psk_len, - const unsigned char *psk_identity, size_t psk_identity_len ) +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 ) { - ssl->psk = psk; + if( psk == NULL || psk_identity == NULL ) + 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 = psk_identity; ssl->psk_identity_len = psk_identity_len; + + ssl->psk = polarssl_malloc( ssl->psk_len ); + ssl->psk_identity = 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 ); +} + +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_PSK_ENABLED */ @@ -4146,7 +4166,7 @@ void ssl_free( ssl_context *ssl ) #endif #if defined(POLARSSL_SSL_SERVER_NAME_INDICATION) - if ( ssl->hostname != NULL) + if ( ssl->hostname != NULL ) { memset( ssl->hostname, 0, ssl->hostname_len ); polarssl_free( ssl->hostname ); @@ -4154,6 +4174,18 @@ void ssl_free( ssl_context *ssl ) } #endif +#if defined(POLARSSL_KEY_EXCHANGE_PSK_ENABLED) + if( ssl->psk != NULL ) + { + memset( ssl->psk, 0, ssl->psk_len ); + memset( ssl->psk_identity, 0, ssl->psk_identity_len ); + polarssl_free( ssl->psk ); + polarssl_free( ssl->psk_identity ); + ssl->psk_len = 0; + ssl->psk_identity_len = 0; + } +#endif + if( ssl->pk_key_own_alloc ) { pk_free( ssl->pk_key );