Date: Mon, 17 Oct 2016 14:03:18 +0000 (UTC) From: Tijl Coosemans <tijl@FreeBSD.org> To: ports-committers@freebsd.org, svn-ports-all@freebsd.org, svn-ports-head@freebsd.org Subject: svn commit: r424117 - in head/security/mbedtls: . files Message-ID: <201610171403.u9HE3Ii5064642@repo.freebsd.org>
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Author: tijl Date: Mon Oct 17 14:03:18 2016 New Revision: 424117 URL: https://svnweb.freebsd.org/changeset/ports/424117 Log: Add DTLS-SRTP (RFC 5764) support for use within Linphone. Obtained from: git://git.linphone.org/linphone-desktop.git Added: head/security/mbedtls/files/patch-dtls-srtp (contents, props changed) Modified: head/security/mbedtls/Makefile Modified: head/security/mbedtls/Makefile ============================================================================== --- head/security/mbedtls/Makefile Mon Oct 17 13:41:22 2016 (r424116) +++ head/security/mbedtls/Makefile Mon Oct 17 14:03:18 2016 (r424117) @@ -3,7 +3,7 @@ PORTNAME= mbedtls PORTVERSION= 2.3.0 DISTVERSIONSUFFIX= -apache -PORTREVISION= 1 +PORTREVISION= 2 CATEGORIES= security devel MASTER_SITES= https://tls.mbed.org/download/ Added: head/security/mbedtls/files/patch-dtls-srtp ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/security/mbedtls/files/patch-dtls-srtp Mon Oct 17 14:03:18 2016 (r424117) @@ -0,0 +1,659 @@ +Add DTLS-SRTP (RFC 5764) support. + +Obtained from: git://git.linphone.org/linphone-desktop.git + +diff --git a/include/mbedtls/config.h b/include/mbedtls/config.h +index d1db0d8..72e2d04 100644 +--- include/mbedtls/config.h ++++ include/mbedtls/config.h +@@ -1154,6 +1154,17 @@ + #define MBEDTLS_SSL_DTLS_HELLO_VERIFY + + /** ++ * \def MBEDTLS_SSL_DTLS_SRTP ++ * ++ * Enable support for DTLS-SRTP, RFC5764 ++ * ++ * Requires: MBEDTLS_SSL_PROTO_DTLS ++ * ++ * Comment this to disable support for DTLS-SRTP. ++ */ ++#define MBEDTLS_SSL_DTLS_SRTP ++ ++/** + * \def MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE + * + * Enable server-side support for clients that reconnect from the same port. +diff --git a/include/mbedtls/ssl.h b/include/mbedtls/ssl.h +index 00e1c6c..729e95f 100644 +--- include/mbedtls/ssl.h ++++ include/mbedtls/ssl.h +@@ -326,6 +326,8 @@ + + #define MBEDTLS_TLS_EXT_SIG_ALG 13 + ++#define MBEDTLS_TLS_EXT_USE_SRTP 14 ++ + #define MBEDTLS_TLS_EXT_ALPN 16 + + #define MBEDTLS_TLS_EXT_ENCRYPT_THEN_MAC 22 /* 0x16 */ +@@ -338,6 +340,14 @@ + #define MBEDTLS_TLS_EXT_RENEGOTIATION_INFO 0xFF01 + + /* ++ * use_srtp extension protection profiles values as defined in http://www.iana.org/assignments/srtp-protection/srtp-protection.xhtml ++ */ ++#define MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_80_IANA_VALUE 0x0001 ++#define MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_32_IANA_VALUE 0x0002 ++#define MBEDTLS_SRTP_NULL_HMAC_SHA1_80_IANA_VALUE 0x0005 ++#define MBEDTLS_SRTP_NULL_HMAC_SHA1_32_IANA_VALUE 0x0006 ++ ++/* + * Size defines + */ + #if !defined(MBEDTLS_PSK_MAX_LEN) +@@ -426,6 +436,19 @@ typedef struct mbedtls_ssl_key_cert mbedtls_ssl_key_cert; + typedef struct mbedtls_ssl_flight_item mbedtls_ssl_flight_item; + #endif + ++#if defined(MBEDTLS_SSL_DTLS_SRTP) ++/* ++ * List of SRTP profiles for DTLS-SRTP ++ */ ++enum mbedtls_DTLS_SRTP_protection_profiles { ++ MBEDTLS_SRTP_UNSET_PROFILE, ++ MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_80, ++ MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_32, ++ MBEDTLS_SRTP_NULL_HMAC_SHA1_80, ++ MBEDTLS_SRTP_NULL_HMAC_SHA1_32, ++}; ++#endif /* MBEDTLS_SSL_DTLS_SRTP */ ++ + /* + * This structure is used for storing current session data. + */ +@@ -566,6 +589,14 @@ struct mbedtls_ssl_config + const char **alpn_list; /*!< ordered list of protocols */ + #endif + ++#if defined(MBEDTLS_SSL_DTLS_SRTP) ++ /* ++ * use_srtp extension ++ */ ++ enum mbedtls_DTLS_SRTP_protection_profiles *dtls_srtp_profiles_list; /*!< ordered list of supported srtp profile */ ++ size_t dtls_srtp_profiles_list_len; /*!< number of supported profiles */ ++#endif /* MBEDTLS_SSL_DTLS_SRTP */ ++ + /* + * Numerical settings (int then char) + */ +@@ -765,6 +796,15 @@ struct mbedtls_ssl_context + const char *alpn_chosen; /*!< negotiated protocol */ + #endif + ++#if defined(MBEDTLS_SSL_DTLS_SRTP) ++ /* ++ * use_srtp extension ++ */ ++ enum mbedtls_DTLS_SRTP_protection_profiles chosen_dtls_srtp_profile; /*!< negotiated SRTP profile */ ++ unsigned char *dtls_srtp_keys; /*<! master keys and master salt for SRTP generated during handshake */ ++ size_t dtls_srtp_keys_len; /*<! length in bytes of master keys and master salt for SRTP generated during handshake */ ++#endif /* MBEDTLS_SSL_DTLS_SRTP */ ++ + /* + * Information for DTLS hello verify + */ +@@ -1781,6 +1821,45 @@ int mbedtls_ssl_conf_alpn_protocols( mbedtls_ssl_config *conf, const char **prot + const char *mbedtls_ssl_get_alpn_protocol( const mbedtls_ssl_context *ssl ); + #endif /* MBEDTLS_SSL_ALPN */ + ++#if defined(MBEDTLS_SSL_DTLS_SRTP) ++/** ++ * \brief Set the supported DTLS-SRTP protection profiles. ++ * ++ * \param ssl SSL configuration ++ * \param protos List of supported protection profiles, ++ * in decreasing preference order. ++ * \param profiles_number Number of supported profiles. ++ * ++ * \return 0 on success, or MBEDTLS_ERR_SSL_BAD_INPUT_DATA. ++ */ ++int mbedtls_ssl_conf_dtls_srtp_protection_profiles( mbedtls_ssl_config *conf, const enum mbedtls_DTLS_SRTP_protection_profiles *profiles, size_t profiles_number); ++ ++/** ++ * \brief Get the negotiated DTLS-SRTP Protection Profile. ++ * This function should be called after the handshake is ++ * completed. ++ * ++ * \param ssl SSL context ++ * ++ * \return Protection Profile enum member, MBEDTLS_SRTP_UNSET_PROFILE if no protocol was negotiated. ++ */ ++enum mbedtls_DTLS_SRTP_protection_profiles mbedtls_ssl_get_dtls_srtp_protection_profile( const mbedtls_ssl_context *ssl); ++ ++/** ++ * \brief Get the generated DTLS-SRTP key material. ++ * This function should be called after the handshake is ++ * completed. It shall returns 80 bytes of key material generated according to RFC5764 ++ * ++ * \param ssl SSL context ++ * \param key Buffer to hold the generated key material ++ * \param key_buffer_len Length in bytes of the key buffer ++ * \param key_len Actual length of data written in the key buffer ++ * ++ * \return 0 on succes, MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL if the key buffer is too small to hold the generated key ++ */ ++int mbedtls_ssl_get_dtls_srtp_key_material( const mbedtls_ssl_context *ssl, unsigned char *key, const size_t key_buffer_len, size_t *key_len ); ++#endif /* MBEDTLS_SSL_DTLS_SRTP */ ++ + /** + * \brief Set the maximum supported version sent from the client side + * and/or accepted at the server side +diff --git a/library/ssl_cli.c b/library/ssl_cli.c +index 4452169..91569ed 100644 +--- library/ssl_cli.c ++++ library/ssl_cli.c +@@ -656,6 +656,79 @@ static void ssl_write_alpn_ext( mbedtls_ssl_context *ssl, + } + #endif /* MBEDTLS_SSL_ALPN */ + ++#if defined (MBEDTLS_SSL_DTLS_SRTP) ++static void ssl_write_use_srtp_ext( mbedtls_ssl_context *ssl, ++ unsigned char *buf, size_t *olen ) ++{ ++ unsigned char *p = buf; ++ size_t protection_profiles_index = 0; ++ ++ *olen = 0; ++ ++ if( (ssl->conf->dtls_srtp_profiles_list == NULL) || (ssl->conf->dtls_srtp_profiles_list_len == 0) ) ++ { ++ return; ++ } ++ ++ MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding use_srtp extension" ) ); ++ ++ *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_USE_SRTP >> 8 ) & 0xFF ); ++ *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_USE_SRTP ) & 0xFF ); ++ ++ /* RFC5764 section 4.1.1 ++ * uint8 SRTPProtectionProfile[2]; ++ * ++ * struct { ++ * SRTPProtectionProfiles SRTPProtectionProfiles; ++ * opaque srtp_mki<0..255>; ++ * } UseSRTPData; ++ ++ * SRTPProtectionProfile SRTPProtectionProfiles<2..2^16-1>; ++ * ++ * Note: srtp_mki is not supported ++ */ ++ ++ /* Extension length = 2bytes for profiles lenght, ssl->conf->dtls_srtp_profiles_list_len*2 (each profile is 2 bytes length ) + 1 byte for the non implemented srtp_mki vector length (always 0) */ ++ *p++ = (unsigned char)( ( ( 2 + 2*(ssl->conf->dtls_srtp_profiles_list_len) + 1 ) >> 8 ) & 0xFF ); ++ *p++ = (unsigned char)( ( ( 2 + 2*(ssl->conf->dtls_srtp_profiles_list_len) + 1 ) ) & 0xFF ); ++ ++ ++ /* protection profile length: 2*(ssl->conf->dtls_srtp_profiles_list_len) */ ++ *p++ = (unsigned char)( ( ( 2*(ssl->conf->dtls_srtp_profiles_list_len) ) >> 8 ) & 0xFF ); ++ *p++ = (unsigned char)( ( 2*(ssl->conf->dtls_srtp_profiles_list_len) ) & 0xFF ); ++ ++ for( protection_profiles_index=0; protection_profiles_index < ssl->conf->dtls_srtp_profiles_list_len; protection_profiles_index++ ) ++ { ++ switch (ssl->conf->dtls_srtp_profiles_list[protection_profiles_index]) { ++ case MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_80: ++ *p++ = ( ( ( MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_80_IANA_VALUE ) >> 8 ) & 0xFF); ++ *p++ = ( ( MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_80_IANA_VALUE ) & 0xFF); ++ break; ++ case MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_32: ++ *p++ = ( ( ( MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_32_IANA_VALUE ) >> 8 ) & 0xFF); ++ *p++ = ( ( MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_32_IANA_VALUE ) & 0xFF); ++ break; ++ case MBEDTLS_SRTP_NULL_HMAC_SHA1_80: ++ *p++ = ( ( ( MBEDTLS_SRTP_NULL_HMAC_SHA1_80_IANA_VALUE ) >> 8 ) & 0xFF); ++ *p++ = ( ( MBEDTLS_SRTP_NULL_HMAC_SHA1_80_IANA_VALUE ) & 0xFF); ++ break; ++ case MBEDTLS_SRTP_NULL_HMAC_SHA1_32: ++ *p++ = ( ( ( MBEDTLS_SRTP_NULL_HMAC_SHA1_32_IANA_VALUE ) >> 8 ) & 0xFF); ++ *p++ = ( ( MBEDTLS_SRTP_NULL_HMAC_SHA1_32_IANA_VALUE ) & 0xFF); ++ break; ++ default: ++ /* Note: we shall never arrive here as protection profiles is checked by ssl_set_dtls_srtp_protection_profiles function */ ++ MBEDTLS_SSL_DEBUG_MSG( 1, ( "client hello, ignore illegal DTLS-SRTP protection profile %d", ssl->conf->dtls_srtp_profiles_list[protection_profiles_index]) ); ++ break; ++ } ++ } ++ ++ *p++ = 0x00; /* non implemented srtp_mki vector length is always 0 */ ++ /* total extension length: extension type (2 bytes) + extension length (2 bytes) + protection profile length (2 bytes) + 2*nb protection profiles + srtp_mki vector length(1 byte)*/ ++ *olen = 2 + 2 + 2 + 2*(ssl->conf->dtls_srtp_profiles_list_len) + 1; ++} ++#endif /* MBEDTLS_SSL_DTLS_SRTP */ ++ + /* + * Generate random bytes for ClientHello + */ +@@ -1006,6 +1079,11 @@ static int ssl_write_client_hello( mbedtls_ssl_context *ssl ) + ext_len += olen; + #endif + ++#if defined(MBEDTLS_SSL_DTLS_SRTP) ++ ssl_write_use_srtp_ext( ssl, p + 2 + ext_len, &olen ); ++ ext_len += olen; ++#endif ++ + #if defined(MBEDTLS_SSL_SESSION_TICKETS) + ssl_write_session_ticket_ext( ssl, p + 2 + ext_len, &olen ); + ext_len += olen; +@@ -1308,6 +1386,81 @@ static int ssl_parse_alpn_ext( mbedtls_ssl_context *ssl, + } + #endif /* MBEDTLS_SSL_ALPN */ + ++#if defined(MBEDTLS_SSL_DTLS_SRTP) ++static int ssl_parse_use_srtp_ext( mbedtls_ssl_context *ssl, ++ const unsigned char *buf, size_t len ) ++{ ++ enum mbedtls_DTLS_SRTP_protection_profiles server_protection = MBEDTLS_SRTP_UNSET_PROFILE; ++ size_t i; ++ uint16_t server_protection_profile_value = 0; ++ ++ /* If use_srtp is not configured, just ignore the extension */ ++ if( ( ssl->conf->dtls_srtp_profiles_list == NULL ) || ( ssl->conf->dtls_srtp_profiles_list_len == 0 ) ) ++ return( 0 ); ++ ++ /* RFC5764 section 4.1.1 ++ * uint8 SRTPProtectionProfile[2]; ++ * ++ * struct { ++ * SRTPProtectionProfiles SRTPProtectionProfiles; ++ * opaque srtp_mki<0..255>; ++ * } UseSRTPData; ++ ++ * SRTPProtectionProfile SRTPProtectionProfiles<2..2^16-1>; ++ * ++ * Note: srtp_mki is not supported ++ */ ++ ++ /* Length is 5 : one protection profile(2 bytes) + length(2 bytes) and potential srtp_mki which won't be parsed */ ++ if( len < 5 ) ++ return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO ); ++ ++ /* ++ * get the server protection profile ++ */ ++ if (((uint16_t)(buf[0]<<8 | buf[1])) != 0x0002) { /* protection profile length must be 0x0002 as we must have only one protection profile in server Hello */ ++ return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO ); ++ } else { ++ server_protection_profile_value = buf[2]<<8 | buf[3]; ++ } ++ ++ /* ++ * Check we have the server profile in our list ++ */ ++ for( i=0; i < ssl->conf->dtls_srtp_profiles_list_len; i++) ++ { ++ switch ( server_protection_profile_value ) { ++ case MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_80_IANA_VALUE: ++ server_protection = MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_80; ++ break; ++ case MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_32_IANA_VALUE: ++ server_protection = MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_32; ++ break; ++ case MBEDTLS_SRTP_NULL_HMAC_SHA1_80_IANA_VALUE: ++ server_protection = MBEDTLS_SRTP_NULL_HMAC_SHA1_80; ++ break; ++ case MBEDTLS_SRTP_NULL_HMAC_SHA1_32_IANA_VALUE: ++ server_protection = MBEDTLS_SRTP_NULL_HMAC_SHA1_32; ++ break; ++ default: ++ server_protection = MBEDTLS_SRTP_UNSET_PROFILE; ++ break; ++ } ++ ++ if (server_protection == ssl->conf->dtls_srtp_profiles_list[i]) { ++ ssl->chosen_dtls_srtp_profile = ssl->conf->dtls_srtp_profiles_list[i]; ++ return 0; ++ } ++ } ++ ++ /* If we get there, no match was found : server problem, it shall never answer with incompatible profile */ ++ ssl->chosen_dtls_srtp_profile = MBEDTLS_SRTP_UNSET_PROFILE; ++ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, ++ MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE ); ++ return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO ); ++} ++#endif /* MBEDTLS_SSL_DTLS_SRTP */ ++ + /* + * Parse HelloVerifyRequest. Only called after verifying the HS type. + */ +@@ -1786,6 +1939,16 @@ static int ssl_parse_server_hello( mbedtls_ssl_context *ssl ) + break; + #endif /* MBEDTLS_SSL_ALPN */ + ++#if defined(MBEDTLS_SSL_DTLS_SRTP) ++ case MBEDTLS_TLS_EXT_USE_SRTP: ++ MBEDTLS_SSL_DEBUG_MSG( 3, ( "found use_srtp extension" ) ); ++ ++ if( ( ret = ssl_parse_use_srtp_ext( ssl, ext + 4, ext_size ) ) != 0 ) ++ return( ret ); ++ ++ break; ++#endif /* MBEDTLS_SSL_DTLS_SRTP */ ++ + default: + MBEDTLS_SSL_DEBUG_MSG( 3, ( "unknown extension found: %d (ignoring)", + ext_id ) ); +diff --git a/library/ssl_srv.c b/library/ssl_srv.c +index 6b5b461..72b50ab 100644 +--- library/ssl_srv.c ++++ library/ssl_srv.c +@@ -573,6 +573,78 @@ static int ssl_parse_alpn_ext( mbedtls_ssl_context *ssl, + } + #endif /* MBEDTLS_SSL_ALPN */ + ++#if defined(MBEDTLS_SSL_DTLS_SRTP) ++static int ssl_parse_use_srtp_ext( mbedtls_ssl_context *ssl, ++ const unsigned char *buf, size_t len ) ++{ ++ enum mbedtls_DTLS_SRTP_protection_profiles client_protection = MBEDTLS_SRTP_UNSET_PROFILE; ++ size_t i,j; ++ uint16_t profile_length; ++ ++ /* If use_srtp is not configured, just ignore the extension */ ++ if( ( ssl->conf->dtls_srtp_profiles_list == NULL ) || ( ssl->conf->dtls_srtp_profiles_list_len == 0 ) ) ++ return( 0 ); ++ ++ /* RFC5764 section 4.1.1 ++ * uint8 SRTPProtectionProfile[2]; ++ * ++ * struct { ++ * SRTPProtectionProfiles SRTPProtectionProfiles; ++ * opaque srtp_mki<0..255>; ++ * } UseSRTPData; ++ ++ * SRTPProtectionProfile SRTPProtectionProfiles<2..2^16-1>; ++ * ++ * Note: srtp_mki is not supported ++ */ ++ ++ /* Min length is 5 : at least one protection profile(2 bytes) and length(2 bytes) + srtp_mki length(1 byte) */ ++ if( len < 5 ) ++ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); ++ ++ /* ++ * Use our order of preference ++ */ ++ profile_length = buf[0]<<8|buf[1]; /* first 2 bytes are protection profile length(in bytes) */ ++ for( i=0; i < ssl->conf->dtls_srtp_profiles_list_len; i++) ++ { ++ /* parse the extension list values are defined in http://www.iana.org/assignments/srtp-protection/srtp-protection.xhtml */ ++ for (j=0; j<profile_length; j+=2) { /* parse only the protection profile, srtp_mki is not supported and ignored */ ++ uint16_t protection_profile_value = buf[j+2]<<8 | buf[j+3]; /* +2 to skip the length field */ ++ ++ switch ( protection_profile_value ) { ++ case MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_80_IANA_VALUE: ++ client_protection = MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_80; ++ break; ++ case MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_32_IANA_VALUE: ++ client_protection = MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_32; ++ break; ++ case MBEDTLS_SRTP_NULL_HMAC_SHA1_80_IANA_VALUE: ++ client_protection = MBEDTLS_SRTP_NULL_HMAC_SHA1_80; ++ break; ++ case MBEDTLS_SRTP_NULL_HMAC_SHA1_32_IANA_VALUE: ++ client_protection = MBEDTLS_SRTP_NULL_HMAC_SHA1_32; ++ break; ++ default: ++ client_protection = MBEDTLS_SRTP_UNSET_PROFILE; ++ break; ++ } ++ ++ if (client_protection == ssl->conf->dtls_srtp_profiles_list[i]) { ++ ssl->chosen_dtls_srtp_profile = ssl->conf->dtls_srtp_profiles_list[i]; ++ return 0; ++ } ++ } ++ } ++ ++ /* If we get there, no match was found */ ++ ssl->chosen_dtls_srtp_profile = MBEDTLS_SRTP_UNSET_PROFILE; ++ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, ++ MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE ); ++ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); ++} ++#endif /* MBEDTLS_SSL_DTLS_SRTP */ ++ + /* + * Auxiliary functions for ServerHello parsing and related actions + */ +@@ -1675,7 +1747,16 @@ read_record_header: + if( ret != 0 ) + return( ret ); + break; +-#endif /* MBEDTLS_SSL_SESSION_TICKETS */ ++#endif /* MBEDTLS_SSL_ALPN */ ++ ++#if defined(MBEDTLS_SSL_DTLS_SRTP) ++ case MBEDTLS_TLS_EXT_USE_SRTP: ++ MBEDTLS_SSL_DEBUG_MSG( 3, ( "found use_srtp extension" ) ); ++ ret = ssl_parse_use_srtp_ext( ssl, ext + 4, ext_size ); ++ if ( ret != 0) ++ return( ret ); ++ break; ++#endif /* MBEDTLS_SSL_DTLS_SRTP */ + + default: + MBEDTLS_SSL_DEBUG_MSG( 3, ( "unknown extension found: %d (ignoring)", +@@ -2144,6 +2225,57 @@ static void ssl_write_alpn_ext( mbedtls_ssl_context *ssl, + } + #endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C */ + ++#if defined(MBEDTLS_SSL_DTLS_SRTP ) ++static void ssl_write_use_srtp_ext( mbedtls_ssl_context *ssl, ++ unsigned char *buf, size_t *olen ) ++{ ++ if( ssl->chosen_dtls_srtp_profile == MBEDTLS_SRTP_UNSET_PROFILE ) ++ { ++ *olen = 0; ++ return; ++ } ++ ++ MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, adding use_srtp extension" ) ); ++ ++ /* extension */ ++ buf[0] = (unsigned char)( ( MBEDTLS_TLS_EXT_USE_SRTP >> 8 ) & 0xFF ); ++ buf[1] = (unsigned char)( ( MBEDTLS_TLS_EXT_USE_SRTP ) & 0xFF ); ++ /* total length (5: only one profile(2 bytes) and length(2bytes) and srtp_mki not supported so zero length(1byte) ) */ ++ buf[2] = 0x00; ++ buf[3] = 0x05; ++ ++ /* protection profile length: 2 */ ++ buf[4] = 0x00; ++ buf[5] = 0x02; ++ switch (ssl->chosen_dtls_srtp_profile) { ++ case MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_80: ++ buf[6] = (unsigned char)( ( MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_80_IANA_VALUE >> 8) & 0xFF ); ++ buf[7] = (unsigned char)( ( MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_80_IANA_VALUE ) & 0xFF ); ++ break; ++ case MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_32: ++ buf[6] = (unsigned char)( ( MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_32_IANA_VALUE >> 8) & 0xFF ); ++ buf[7] = (unsigned char)( ( MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_32_IANA_VALUE ) & 0xFF ); ++ break; ++ case MBEDTLS_SRTP_NULL_HMAC_SHA1_80: ++ buf[6] = (unsigned char)( ( MBEDTLS_SRTP_NULL_HMAC_SHA1_80_IANA_VALUE >> 8) & 0xFF ); ++ buf[7] = (unsigned char)( ( MBEDTLS_SRTP_NULL_HMAC_SHA1_80_IANA_VALUE ) & 0xFF ); ++ break; ++ case MBEDTLS_SRTP_NULL_HMAC_SHA1_32: ++ buf[6] = (unsigned char)( ( MBEDTLS_SRTP_NULL_HMAC_SHA1_32_IANA_VALUE >> 8) & 0xFF ); ++ buf[7] = (unsigned char)( ( MBEDTLS_SRTP_NULL_HMAC_SHA1_32_IANA_VALUE ) & 0xFF ); ++ break; ++ default: ++ *olen = 0; ++ return; ++ break; ++ } ++ ++ buf[8] = 0x00; /* unsupported srtp_mki variable length vector set to 0 */ ++ ++ *olen = 9; ++} ++#endif /* MBEDTLS_SSL_DTLS_SRTP */ ++ + #if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY) + static int ssl_write_hello_verify_request( mbedtls_ssl_context *ssl ) + { +@@ -2408,6 +2540,11 @@ static int ssl_write_server_hello( mbedtls_ssl_context *ssl ) + ext_len += olen; + #endif + ++#if defined(MBEDTLS_SSL_DTLS_SRTP) ++ ssl_write_use_srtp_ext( ssl, p + 2 + ext_len, &olen); ++ ext_len += olen; ++#endif ++ + MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, total extension length: %d", ext_len ) ); + + if( ext_len > 0 ) +diff --git a/library/ssl_tls.c b/library/ssl_tls.c +index 4424f56..940f8aa 100644 +--- library/ssl_tls.c ++++ library/ssl_tls.c +@@ -373,7 +373,7 @@ static int tls_prf_generic( mbedtls_md_type_t md_type, + { + size_t nb; + size_t i, j, k, md_len; +- unsigned char tmp[128]; ++ unsigned char tmp[144]; + unsigned char h_i[MBEDTLS_MD_MAX_SIZE]; + const mbedtls_md_info_t *md_info; + mbedtls_md_context_t md_ctx; +@@ -636,6 +636,30 @@ int mbedtls_ssl_derive_keys( mbedtls_ssl_context *ssl ) + else + MBEDTLS_SSL_DEBUG_MSG( 3, ( "no premaster (session resumed)" ) ); + ++#if defined(MBEDTLS_SSL_DTLS_SRTP) ++ /* check if we have a chosen srtp protection profile */ ++ if (ssl->chosen_dtls_srtp_profile != MBEDTLS_SRTP_UNSET_PROFILE) { ++ /* derive key material for srtp session RFC5764 section 4.2 */ ++ /* master key and master salt are respectively 128 bits and 112 bits for all currently available modes : ++ * SRTP_AES128_CM_HMAC_SHA1_80, SRTP_AES128_CM_HMAC_SHA1_32 ++ * SRTP_NULL_HMAC_SHA1_80, SRTP_NULL_HMAC_SHA1_32 ++ * So we must export 2*(128 + 112) = 480 bits ++ */ ++ ssl->dtls_srtp_keys_len = 60; ++ ++ ssl->dtls_srtp_keys = (unsigned char *)mbedtls_calloc(1, ssl->dtls_srtp_keys_len); ++ ++ ret = handshake->tls_prf( session->master, 48, "EXTRACTOR-dtls_srtp", ++ handshake->randbytes, 64, ssl->dtls_srtp_keys, ssl->dtls_srtp_keys_len ); ++ ++ if( ret != 0 ) ++ { ++ MBEDTLS_SSL_DEBUG_RET( 1, "dtls srtp prf", ret ); ++ return( ret ); ++ } ++ } ++#endif /* MBEDTLS_SSL_DTLS_SRTP */ ++ + /* + * Swap the client and server random values. + */ +@@ -5408,6 +5432,12 @@ int mbedtls_ssl_setup( mbedtls_ssl_context *ssl, + ssl->in_msg = ssl->in_buf + 13; + } + ++#if defined(MBEDTLS_SSL_DTLS_SRTP) ++ ssl->chosen_dtls_srtp_profile = MBEDTLS_SRTP_UNSET_PROFILE; ++ ssl->dtls_srtp_keys = NULL; ++ ssl->dtls_srtp_keys_len = 0; ++#endif ++ + if( ( ret = ssl_handshake_init( ssl ) ) != 0 ) + return( ret ); + +@@ -5997,6 +6027,61 @@ const char *mbedtls_ssl_get_alpn_protocol( const mbedtls_ssl_context *ssl ) + } + #endif /* MBEDTLS_SSL_ALPN */ + ++#if defined(MBEDTLS_SSL_DTLS_SRTP) ++int mbedtls_ssl_conf_dtls_srtp_protection_profiles( mbedtls_ssl_config *conf, const enum mbedtls_DTLS_SRTP_protection_profiles *profiles, size_t profiles_number) ++{ ++ size_t i; ++ /* check in put validity : must be a list of profiles from enumeration */ ++ /* maximum length is 4 as only 4 protection profiles are defined */ ++ if (profiles_number>4) { ++ return MBEDTLS_ERR_SSL_BAD_INPUT_DATA; ++ } ++ ++ mbedtls_free(conf->dtls_srtp_profiles_list); ++ conf->dtls_srtp_profiles_list = (enum mbedtls_DTLS_SRTP_protection_profiles *)mbedtls_calloc(1, profiles_number*sizeof(enum mbedtls_DTLS_SRTP_protection_profiles)); ++ ++ for (i=0; i<profiles_number; i++) { ++ switch (profiles[i]) { ++ case MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_80: ++ case MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_32: ++ case MBEDTLS_SRTP_NULL_HMAC_SHA1_80: ++ case MBEDTLS_SRTP_NULL_HMAC_SHA1_32: ++ conf->dtls_srtp_profiles_list[i] = profiles[i]; ++ break; ++ default: ++ mbedtls_free(conf->dtls_srtp_profiles_list); ++ conf->dtls_srtp_profiles_list = NULL; ++ conf->dtls_srtp_profiles_list_len = 0; ++ return MBEDTLS_ERR_SSL_BAD_INPUT_DATA; ++ } ++ } ++ ++ /* assign array length */ ++ conf->dtls_srtp_profiles_list_len = profiles_number; ++ ++ return( 0 ); ++} ++ ++enum mbedtls_DTLS_SRTP_protection_profiles mbedtls_ssl_get_dtls_srtp_protection_profile( const mbedtls_ssl_context *ssl) ++{ ++ return( ssl->chosen_dtls_srtp_profile); ++} ++ ++int mbedtls_ssl_get_dtls_srtp_key_material( const mbedtls_ssl_context *ssl, unsigned char *key, const size_t key_buffer_len, size_t *key_len ) { ++ *key_len = 0; ++ ++ /* check output buffer size */ ++ if ( key_buffer_len < ssl->dtls_srtp_keys_len) { ++ return MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL; ++ } ++ ++ memcpy( key, ssl->dtls_srtp_keys, ssl->dtls_srtp_keys_len); ++ *key_len = ssl->dtls_srtp_keys_len; ++ ++ return 0; ++} ++#endif /* MBEDTLS_SSL_DTLS_SRTP */ ++ + void mbedtls_ssl_conf_max_version( mbedtls_ssl_config *conf, int major, int minor ) + { + conf->max_major_ver = major; +@@ -7083,6 +7169,11 @@ void mbedtls_ssl_free( mbedtls_ssl_context *ssl ) + mbedtls_free( ssl->cli_id ); + #endif + ++#if defined (MBEDTLS_SSL_DTLS_SRTP) ++ mbedtls_zeroize( ssl->dtls_srtp_keys, ssl->dtls_srtp_keys_len ); ++ mbedtls_free( ssl->dtls_srtp_keys ); ++#endif /* MBEDTLS_SSL_DTLS_SRTP */ ++ + MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= free" ) ); + + /* Actually clear after last debug message */ +@@ -7311,6 +7402,10 @@ void mbedtls_ssl_config_free( mbedtls_ssl_config *conf ) + ssl_key_cert_free( conf->key_cert ); + #endif + ++#if defined (MBEDTLS_SSL_DTLS_SRTP) ++ mbedtls_free( conf->dtls_srtp_profiles_list ); ++#endif ++ + mbedtls_zeroize( conf, sizeof( mbedtls_ssl_config ) ); + } +
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