From d18cc57962e3978317e595f23eac47d3245f7493 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Manuel=20P=C3=A9gouri=C3=A9-Gonnard?= Date: Wed, 11 Dec 2013 17:45:46 +0100 Subject: [PATCH] Add client-side support for ECDH key exchanges --- library/ssl_cli.c | 93 ++++++++++++++++++++++++++++++++++++++++++----- library/ssl_tls.c | 22 +++++++---- 2 files changed, 97 insertions(+), 18 deletions(-) diff --git a/library/ssl_cli.c b/library/ssl_cli.c index 0f9a73115..76c943d96 100644 --- a/library/ssl_cli.c +++ b/library/ssl_cli.c @@ -1113,6 +1113,29 @@ static int ssl_parse_server_dh_params( ssl_context *ssl, unsigned char **p, #endif /* POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED || POLARSSL_KEY_EXCHANGE_DHE_PSK_ENABLED */ +#if defined(POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \ + defined(POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) || \ + defined(POLARSSL_KEY_EXCHANGE_ECDHE_PSK_ENABLED) || \ + defined(POLARSSL_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \ + defined(POLARSSL_KEY_EXCHANGE_ECDH_ECDSA_ENABLED) +static int ssl_check_server_ecdh_params( const ssl_context *ssl ) +{ + SSL_DEBUG_MSG( 2, ( "ECDH curve size: %d", + (int) ssl->handshake->ecdh_ctx.grp.nbits ) ); + + if( ssl->handshake->ecdh_ctx.grp.nbits < 163 || + ssl->handshake->ecdh_ctx.grp.nbits > 521 ) + { + return( -1 ); + } + + SSL_DEBUG_ECP( 3, "ECDH: Qp", &ssl->handshake->ecdh_ctx.Qp ); + + return( 0 ); +} +#endif + + #if defined(POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \ defined(POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) || \ defined(POLARSSL_KEY_EXCHANGE_ECDHE_PSK_ENABLED) @@ -1137,18 +1160,12 @@ static int ssl_parse_server_ecdh_params( ssl_context *ssl, return( ret ); } - SSL_DEBUG_MSG( 2, ( "ECDH curve size: %d", - (int) ssl->handshake->ecdh_ctx.grp.nbits ) ); - - if( ssl->handshake->ecdh_ctx.grp.nbits < 163 || - ssl->handshake->ecdh_ctx.grp.nbits > 521 ) + if( ssl_check_server_ecdh_params( ssl ) != 0 ) { SSL_DEBUG_MSG( 1, ( "bad server key exchange message (ECDH length)" ) ); return( POLARSSL_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE ); } - SSL_DEBUG_ECP( 3, "ECDH: Qp", &ssl->handshake->ecdh_ctx.Qp ); - return( ret ); } #endif /* POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED || @@ -1307,6 +1324,41 @@ static int ssl_parse_signature_algorithm( ssl_context *ssl, POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */ #endif /* POLARSSL_SSL_PROTO_TLS1_2 */ + +#if defined(POLARSSL_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \ + defined(POLARSSL_KEY_EXCHANGE_ECDH_ECDSA_ENABLED) +static int ssl_get_ecdh_params_from_cert( ssl_context *ssl ) +{ + int ret; + const ecp_keypair *peer_key; + + if( ! pk_can_do( &ssl->session_negotiate->peer_cert->pk, + POLARSSL_PK_ECKEY ) ) + { + SSL_DEBUG_MSG( 1, ( "server key not ECDH capable" ) ); + return( POLARSSL_ERR_SSL_PK_TYPE_MISMATCH ); + } + + peer_key = pk_ec( ssl->session_negotiate->peer_cert->pk ); + + if( ( ret = ecdh_get_params( &ssl->handshake->ecdh_ctx, peer_key, + POLARSSL_ECDH_THEIRS ) ) != 0 ) + { + SSL_DEBUG_RET( 1, ( "ecdh_get_params" ), ret ); + return( ret ); + } + + if( ssl_check_server_ecdh_params( ssl ) != 0 ) + { + SSL_DEBUG_MSG( 1, ( "bad server certificate (ECDH length)" ) ); + return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE ); + } + + return( ret ); +} +#endif /* POLARSSL_KEY_EXCHANGE_ECDH_RSA_ENABLED) || + POLARSSL_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */ + static int ssl_parse_server_key_exchange( ssl_context *ssl ) { int ret; @@ -1335,6 +1387,21 @@ static int ssl_parse_server_key_exchange( ssl_context *ssl ) ((void) end); #endif +#if defined(POLARSSL_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \ + defined(POLARSSL_KEY_EXCHANGE_ECDH_ECDSA_ENABLED) + if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDH_RSA || + ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDH_ECDSA ) + { + ssl_get_ecdh_params_from_cert( ssl ); + + SSL_DEBUG_MSG( 2, ( "<= skip parse server key exchange" ) ); + ssl->state++; + return( 0 ); + } + ((void) p); + ((void) end); +#endif + if( ( ret = ssl_read_record( ssl ) ) != 0 ) { SSL_DEBUG_RET( 1, "ssl_read_record", ret ); @@ -1852,9 +1919,13 @@ static int ssl_write_client_key_exchange( ssl_context *ssl ) else #endif /* POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED */ #if defined(POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED) || \ - defined(POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) + defined(POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) || \ + defined(POLARSSL_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \ + defined(POLARSSL_KEY_EXCHANGE_ECDH_ECDSA_ENABLED) if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_RSA || - ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA ) + ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA || + ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDH_RSA || + ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDH_ECDSA ) { /* * ECDH key exchange -- send client public value @@ -1887,7 +1958,9 @@ static int ssl_write_client_key_exchange( ssl_context *ssl ) } else #endif /* POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED || - POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */ + POLARSSL_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED || + POLARSSL_KEY_EXCHANGE_ECDH_RSA_ENABLED || + POLARSSL_KEY_EXCHANGE_ECDH_ECDSA_ENABLED */ #if defined(POLARSSL_KEY_EXCHANGE__SOME__PSK_ENABLED) if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_PSK || ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_RSA_PSK || diff --git a/library/ssl_tls.c b/library/ssl_tls.c index a903b3e0d..ce05d7a2e 100644 --- a/library/ssl_tls.c +++ b/library/ssl_tls.c @@ -2316,11 +2316,13 @@ int ssl_send_alert_message( ssl_context *ssl, /* * 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) +#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 ) { int ret = POLARSSL_ERR_SSL_FEATURE_UNAVAILABLE; @@ -2649,9 +2651,13 @@ int ssl_parse_certificate( ssl_context *ssl ) return( ret ); } -#endif /* !POLARSSL_KEY_EXCHANGE_RSA_ENABLED && - !POLARSSL_KEY_EXCHANGE_DHE_RSA_ENABLED && - !POLARSSL_KEY_EXCHANGE_ECDHE_RSA_ENABLED */ +#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 ) {