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Lines 1-659
Link Here
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| 1 |
Add DTLS-SRTP (RFC 5764) support. |
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| 2 |
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| 3 |
Obtained from: git://git.linphone.org/linphone-desktop.git |
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| 5 |
diff --git a/include/mbedtls/config.h b/include/mbedtls/config.h |
| 6 |
index d1db0d8..72e2d04 100644 |
| 7 |
--- include/mbedtls/config.h |
| 8 |
+++ include/mbedtls/config.h |
| 9 |
@@ -1154,6 +1154,17 @@ |
| 10 |
#define MBEDTLS_SSL_DTLS_HELLO_VERIFY |
| 11 |
|
| 12 |
/** |
| 13 |
+ * \def MBEDTLS_SSL_DTLS_SRTP |
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+ * |
| 15 |
+ * Enable support for DTLS-SRTP, RFC5764 |
| 16 |
+ * |
| 17 |
+ * Requires: MBEDTLS_SSL_PROTO_DTLS |
| 18 |
+ * |
| 19 |
+ * Comment this to disable support for DTLS-SRTP. |
| 20 |
+ */ |
| 21 |
+#define MBEDTLS_SSL_DTLS_SRTP |
| 22 |
+ |
| 23 |
+/** |
| 24 |
* \def MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE |
| 25 |
* |
| 26 |
* Enable server-side support for clients that reconnect from the same port. |
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diff --git a/include/mbedtls/ssl.h b/include/mbedtls/ssl.h |
| 28 |
index 00e1c6c..729e95f 100644 |
| 29 |
--- include/mbedtls/ssl.h |
| 30 |
+++ include/mbedtls/ssl.h |
| 31 |
@@ -326,6 +326,8 @@ |
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| 33 |
#define MBEDTLS_TLS_EXT_SIG_ALG 13 |
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|
| 35 |
+#define MBEDTLS_TLS_EXT_USE_SRTP 14 |
| 36 |
+ |
| 37 |
#define MBEDTLS_TLS_EXT_ALPN 16 |
| 38 |
|
| 39 |
#define MBEDTLS_TLS_EXT_ENCRYPT_THEN_MAC 22 /* 0x16 */ |
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@@ -338,6 +340,14 @@ |
| 41 |
#define MBEDTLS_TLS_EXT_RENEGOTIATION_INFO 0xFF01 |
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|
| 43 |
/* |
| 44 |
+ * use_srtp extension protection profiles values as defined in http://www.iana.org/assignments/srtp-protection/srtp-protection.xhtml |
| 45 |
+ */ |
| 46 |
+#define MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_80_IANA_VALUE 0x0001 |
| 47 |
+#define MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_32_IANA_VALUE 0x0002 |
| 48 |
+#define MBEDTLS_SRTP_NULL_HMAC_SHA1_80_IANA_VALUE 0x0005 |
| 49 |
+#define MBEDTLS_SRTP_NULL_HMAC_SHA1_32_IANA_VALUE 0x0006 |
| 50 |
+ |
| 51 |
+/* |
| 52 |
* Size defines |
| 53 |
*/ |
| 54 |
#if !defined(MBEDTLS_PSK_MAX_LEN) |
| 55 |
@@ -426,6 +436,19 @@ typedef struct mbedtls_ssl_key_cert mbedtls_ssl_key_cert; |
| 56 |
typedef struct mbedtls_ssl_flight_item mbedtls_ssl_flight_item; |
| 57 |
#endif |
| 58 |
|
| 59 |
+#if defined(MBEDTLS_SSL_DTLS_SRTP) |
| 60 |
+/* |
| 61 |
+ * List of SRTP profiles for DTLS-SRTP |
| 62 |
+ */ |
| 63 |
+enum mbedtls_DTLS_SRTP_protection_profiles { |
| 64 |
+ MBEDTLS_SRTP_UNSET_PROFILE, |
| 65 |
+ MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_80, |
| 66 |
+ MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_32, |
| 67 |
+ MBEDTLS_SRTP_NULL_HMAC_SHA1_80, |
| 68 |
+ MBEDTLS_SRTP_NULL_HMAC_SHA1_32, |
| 69 |
+}; |
| 70 |
+#endif /* MBEDTLS_SSL_DTLS_SRTP */ |
| 71 |
+ |
| 72 |
/* |
| 73 |
* This structure is used for storing current session data. |
| 74 |
*/ |
| 75 |
@@ -566,6 +589,14 @@ struct mbedtls_ssl_config |
| 76 |
const char **alpn_list; /*!< ordered list of protocols */ |
| 77 |
#endif |
| 78 |
|
| 79 |
+#if defined(MBEDTLS_SSL_DTLS_SRTP) |
| 80 |
+ /* |
| 81 |
+ * use_srtp extension |
| 82 |
+ */ |
| 83 |
+ enum mbedtls_DTLS_SRTP_protection_profiles *dtls_srtp_profiles_list; /*!< ordered list of supported srtp profile */ |
| 84 |
+ size_t dtls_srtp_profiles_list_len; /*!< number of supported profiles */ |
| 85 |
+#endif /* MBEDTLS_SSL_DTLS_SRTP */ |
| 86 |
+ |
| 87 |
/* |
| 88 |
* Numerical settings (int then char) |
| 89 |
*/ |
| 90 |
@@ -765,6 +796,15 @@ struct mbedtls_ssl_context |
| 91 |
const char *alpn_chosen; /*!< negotiated protocol */ |
| 92 |
#endif |
| 93 |
|
| 94 |
+#if defined(MBEDTLS_SSL_DTLS_SRTP) |
| 95 |
+ /* |
| 96 |
+ * use_srtp extension |
| 97 |
+ */ |
| 98 |
+ enum mbedtls_DTLS_SRTP_protection_profiles chosen_dtls_srtp_profile; /*!< negotiated SRTP profile */ |
| 99 |
+ unsigned char *dtls_srtp_keys; /*<! master keys and master salt for SRTP generated during handshake */ |
| 100 |
+ size_t dtls_srtp_keys_len; /*<! length in bytes of master keys and master salt for SRTP generated during handshake */ |
| 101 |
+#endif /* MBEDTLS_SSL_DTLS_SRTP */ |
| 102 |
+ |
| 103 |
/* |
| 104 |
* Information for DTLS hello verify |
| 105 |
*/ |
| 106 |
@@ -1781,6 +1821,45 @@ int mbedtls_ssl_conf_alpn_protocols( mbedtls_ssl_config *conf, const char **prot |
| 107 |
const char *mbedtls_ssl_get_alpn_protocol( const mbedtls_ssl_context *ssl ); |
| 108 |
#endif /* MBEDTLS_SSL_ALPN */ |
| 109 |
|
| 110 |
+#if defined(MBEDTLS_SSL_DTLS_SRTP) |
| 111 |
+/** |
| 112 |
+ * \brief Set the supported DTLS-SRTP protection profiles. |
| 113 |
+ * |
| 114 |
+ * \param ssl SSL configuration |
| 115 |
+ * \param protos List of supported protection profiles, |
| 116 |
+ * in decreasing preference order. |
| 117 |
+ * \param profiles_number Number of supported profiles. |
| 118 |
+ * |
| 119 |
+ * \return 0 on success, or MBEDTLS_ERR_SSL_BAD_INPUT_DATA. |
| 120 |
+ */ |
| 121 |
+int mbedtls_ssl_conf_dtls_srtp_protection_profiles( mbedtls_ssl_config *conf, const enum mbedtls_DTLS_SRTP_protection_profiles *profiles, size_t profiles_number); |
| 122 |
+ |
| 123 |
+/** |
| 124 |
+ * \brief Get the negotiated DTLS-SRTP Protection Profile. |
| 125 |
+ * This function should be called after the handshake is |
| 126 |
+ * completed. |
| 127 |
+ * |
| 128 |
+ * \param ssl SSL context |
| 129 |
+ * |
| 130 |
+ * \return Protection Profile enum member, MBEDTLS_SRTP_UNSET_PROFILE if no protocol was negotiated. |
| 131 |
+ */ |
| 132 |
+enum mbedtls_DTLS_SRTP_protection_profiles mbedtls_ssl_get_dtls_srtp_protection_profile( const mbedtls_ssl_context *ssl); |
| 133 |
+ |
| 134 |
+/** |
| 135 |
+ * \brief Get the generated DTLS-SRTP key material. |
| 136 |
+ * This function should be called after the handshake is |
| 137 |
+ * completed. It shall returns 80 bytes of key material generated according to RFC5764 |
| 138 |
+ * |
| 139 |
+ * \param ssl SSL context |
| 140 |
+ * \param key Buffer to hold the generated key material |
| 141 |
+ * \param key_buffer_len Length in bytes of the key buffer |
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+ * \param key_len Actual length of data written in the key buffer |
| 143 |
+ * |
| 144 |
+ * \return 0 on succes, MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL if the key buffer is too small to hold the generated key |
| 145 |
+ */ |
| 146 |
+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 ); |
| 147 |
+#endif /* MBEDTLS_SSL_DTLS_SRTP */ |
| 148 |
+ |
| 149 |
/** |
| 150 |
* \brief Set the maximum supported version sent from the client side |
| 151 |
* and/or accepted at the server side |
| 152 |
diff --git a/library/ssl_cli.c b/library/ssl_cli.c |
| 153 |
index 4452169..91569ed 100644 |
| 154 |
--- library/ssl_cli.c |
| 155 |
+++ library/ssl_cli.c |
| 156 |
@@ -656,6 +656,79 @@ static void ssl_write_alpn_ext( mbedtls_ssl_context *ssl, |
| 157 |
} |
| 158 |
#endif /* MBEDTLS_SSL_ALPN */ |
| 159 |
|
| 160 |
+#if defined (MBEDTLS_SSL_DTLS_SRTP) |
| 161 |
+static void ssl_write_use_srtp_ext( mbedtls_ssl_context *ssl, |
| 162 |
+ unsigned char *buf, size_t *olen ) |
| 163 |
+{ |
| 164 |
+ unsigned char *p = buf; |
| 165 |
+ size_t protection_profiles_index = 0; |
| 166 |
+ |
| 167 |
+ *olen = 0; |
| 168 |
+ |
| 169 |
+ if( (ssl->conf->dtls_srtp_profiles_list == NULL) || (ssl->conf->dtls_srtp_profiles_list_len == 0) ) |
| 170 |
+ { |
| 171 |
+ return; |
| 172 |
+ } |
| 173 |
+ |
| 174 |
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding use_srtp extension" ) ); |
| 175 |
+ |
| 176 |
+ *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_USE_SRTP >> 8 ) & 0xFF ); |
| 177 |
+ *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_USE_SRTP ) & 0xFF ); |
| 178 |
+ |
| 179 |
+ /* RFC5764 section 4.1.1 |
| 180 |
+ * uint8 SRTPProtectionProfile[2]; |
| 181 |
+ * |
| 182 |
+ * struct { |
| 183 |
+ * SRTPProtectionProfiles SRTPProtectionProfiles; |
| 184 |
+ * opaque srtp_mki<0..255>; |
| 185 |
+ * } UseSRTPData; |
| 186 |
+ |
| 187 |
+ * SRTPProtectionProfile SRTPProtectionProfiles<2..2^16-1>; |
| 188 |
+ * |
| 189 |
+ * Note: srtp_mki is not supported |
| 190 |
+ */ |
| 191 |
+ |
| 192 |
+ /* 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) */ |
| 193 |
+ *p++ = (unsigned char)( ( ( 2 + 2*(ssl->conf->dtls_srtp_profiles_list_len) + 1 ) >> 8 ) & 0xFF ); |
| 194 |
+ *p++ = (unsigned char)( ( ( 2 + 2*(ssl->conf->dtls_srtp_profiles_list_len) + 1 ) ) & 0xFF ); |
| 195 |
+ |
| 196 |
+ |
| 197 |
+ /* protection profile length: 2*(ssl->conf->dtls_srtp_profiles_list_len) */ |
| 198 |
+ *p++ = (unsigned char)( ( ( 2*(ssl->conf->dtls_srtp_profiles_list_len) ) >> 8 ) & 0xFF ); |
| 199 |
+ *p++ = (unsigned char)( ( 2*(ssl->conf->dtls_srtp_profiles_list_len) ) & 0xFF ); |
| 200 |
+ |
| 201 |
+ for( protection_profiles_index=0; protection_profiles_index < ssl->conf->dtls_srtp_profiles_list_len; protection_profiles_index++ ) |
| 202 |
+ { |
| 203 |
+ switch (ssl->conf->dtls_srtp_profiles_list[protection_profiles_index]) { |
| 204 |
+ case MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_80: |
| 205 |
+ *p++ = ( ( ( MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_80_IANA_VALUE ) >> 8 ) & 0xFF); |
| 206 |
+ *p++ = ( ( MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_80_IANA_VALUE ) & 0xFF); |
| 207 |
+ break; |
| 208 |
+ case MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_32: |
| 209 |
+ *p++ = ( ( ( MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_32_IANA_VALUE ) >> 8 ) & 0xFF); |
| 210 |
+ *p++ = ( ( MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_32_IANA_VALUE ) & 0xFF); |
| 211 |
+ break; |
| 212 |
+ case MBEDTLS_SRTP_NULL_HMAC_SHA1_80: |
| 213 |
+ *p++ = ( ( ( MBEDTLS_SRTP_NULL_HMAC_SHA1_80_IANA_VALUE ) >> 8 ) & 0xFF); |
| 214 |
+ *p++ = ( ( MBEDTLS_SRTP_NULL_HMAC_SHA1_80_IANA_VALUE ) & 0xFF); |
| 215 |
+ break; |
| 216 |
+ case MBEDTLS_SRTP_NULL_HMAC_SHA1_32: |
| 217 |
+ *p++ = ( ( ( MBEDTLS_SRTP_NULL_HMAC_SHA1_32_IANA_VALUE ) >> 8 ) & 0xFF); |
| 218 |
+ *p++ = ( ( MBEDTLS_SRTP_NULL_HMAC_SHA1_32_IANA_VALUE ) & 0xFF); |
| 219 |
+ break; |
| 220 |
+ default: |
| 221 |
+ /* Note: we shall never arrive here as protection profiles is checked by ssl_set_dtls_srtp_protection_profiles function */ |
| 222 |
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "client hello, ignore illegal DTLS-SRTP protection profile %d", ssl->conf->dtls_srtp_profiles_list[protection_profiles_index]) ); |
| 223 |
+ break; |
| 224 |
+ } |
| 225 |
+ } |
| 226 |
+ |
| 227 |
+ *p++ = 0x00; /* non implemented srtp_mki vector length is always 0 */ |
| 228 |
+ /* 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)*/ |
| 229 |
+ *olen = 2 + 2 + 2 + 2*(ssl->conf->dtls_srtp_profiles_list_len) + 1; |
| 230 |
+} |
| 231 |
+#endif /* MBEDTLS_SSL_DTLS_SRTP */ |
| 232 |
+ |
| 233 |
/* |
| 234 |
* Generate random bytes for ClientHello |
| 235 |
*/ |
| 236 |
@@ -1006,6 +1079,11 @@ static int ssl_write_client_hello( mbedtls_ssl_context *ssl ) |
| 237 |
ext_len += olen; |
| 238 |
#endif |
| 239 |
|
| 240 |
+#if defined(MBEDTLS_SSL_DTLS_SRTP) |
| 241 |
+ ssl_write_use_srtp_ext( ssl, p + 2 + ext_len, &olen ); |
| 242 |
+ ext_len += olen; |
| 243 |
+#endif |
| 244 |
+ |
| 245 |
#if defined(MBEDTLS_SSL_SESSION_TICKETS) |
| 246 |
ssl_write_session_ticket_ext( ssl, p + 2 + ext_len, &olen ); |
| 247 |
ext_len += olen; |
| 248 |
@@ -1308,6 +1386,81 @@ static int ssl_parse_alpn_ext( mbedtls_ssl_context *ssl, |
| 249 |
} |
| 250 |
#endif /* MBEDTLS_SSL_ALPN */ |
| 251 |
|
| 252 |
+#if defined(MBEDTLS_SSL_DTLS_SRTP) |
| 253 |
+static int ssl_parse_use_srtp_ext( mbedtls_ssl_context *ssl, |
| 254 |
+ const unsigned char *buf, size_t len ) |
| 255 |
+{ |
| 256 |
+ enum mbedtls_DTLS_SRTP_protection_profiles server_protection = MBEDTLS_SRTP_UNSET_PROFILE; |
| 257 |
+ size_t i; |
| 258 |
+ uint16_t server_protection_profile_value = 0; |
| 259 |
+ |
| 260 |
+ /* If use_srtp is not configured, just ignore the extension */ |
| 261 |
+ if( ( ssl->conf->dtls_srtp_profiles_list == NULL ) || ( ssl->conf->dtls_srtp_profiles_list_len == 0 ) ) |
| 262 |
+ return( 0 ); |
| 263 |
+ |
| 264 |
+ /* RFC5764 section 4.1.1 |
| 265 |
+ * uint8 SRTPProtectionProfile[2]; |
| 266 |
+ * |
| 267 |
+ * struct { |
| 268 |
+ * SRTPProtectionProfiles SRTPProtectionProfiles; |
| 269 |
+ * opaque srtp_mki<0..255>; |
| 270 |
+ * } UseSRTPData; |
| 271 |
+ |
| 272 |
+ * SRTPProtectionProfile SRTPProtectionProfiles<2..2^16-1>; |
| 273 |
+ * |
| 274 |
+ * Note: srtp_mki is not supported |
| 275 |
+ */ |
| 276 |
+ |
| 277 |
+ /* Length is 5 : one protection profile(2 bytes) + length(2 bytes) and potential srtp_mki which won't be parsed */ |
| 278 |
+ if( len < 5 ) |
| 279 |
+ return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO ); |
| 280 |
+ |
| 281 |
+ /* |
| 282 |
+ * get the server protection profile |
| 283 |
+ */ |
| 284 |
+ 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 */ |
| 285 |
+ return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO ); |
| 286 |
+ } else { |
| 287 |
+ server_protection_profile_value = buf[2]<<8 | buf[3]; |
| 288 |
+ } |
| 289 |
+ |
| 290 |
+ /* |
| 291 |
+ * Check we have the server profile in our list |
| 292 |
+ */ |
| 293 |
+ for( i=0; i < ssl->conf->dtls_srtp_profiles_list_len; i++) |
| 294 |
+ { |
| 295 |
+ switch ( server_protection_profile_value ) { |
| 296 |
+ case MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_80_IANA_VALUE: |
| 297 |
+ server_protection = MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_80; |
| 298 |
+ break; |
| 299 |
+ case MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_32_IANA_VALUE: |
| 300 |
+ server_protection = MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_32; |
| 301 |
+ break; |
| 302 |
+ case MBEDTLS_SRTP_NULL_HMAC_SHA1_80_IANA_VALUE: |
| 303 |
+ server_protection = MBEDTLS_SRTP_NULL_HMAC_SHA1_80; |
| 304 |
+ break; |
| 305 |
+ case MBEDTLS_SRTP_NULL_HMAC_SHA1_32_IANA_VALUE: |
| 306 |
+ server_protection = MBEDTLS_SRTP_NULL_HMAC_SHA1_32; |
| 307 |
+ break; |
| 308 |
+ default: |
| 309 |
+ server_protection = MBEDTLS_SRTP_UNSET_PROFILE; |
| 310 |
+ break; |
| 311 |
+ } |
| 312 |
+ |
| 313 |
+ if (server_protection == ssl->conf->dtls_srtp_profiles_list[i]) { |
| 314 |
+ ssl->chosen_dtls_srtp_profile = ssl->conf->dtls_srtp_profiles_list[i]; |
| 315 |
+ return 0; |
| 316 |
+ } |
| 317 |
+ } |
| 318 |
+ |
| 319 |
+ /* If we get there, no match was found : server problem, it shall never answer with incompatible profile */ |
| 320 |
+ ssl->chosen_dtls_srtp_profile = MBEDTLS_SRTP_UNSET_PROFILE; |
| 321 |
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| 322 |
+ MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE ); |
| 323 |
+ return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO ); |
| 324 |
+} |
| 325 |
+#endif /* MBEDTLS_SSL_DTLS_SRTP */ |
| 326 |
+ |
| 327 |
/* |
| 328 |
* Parse HelloVerifyRequest. Only called after verifying the HS type. |
| 329 |
*/ |
| 330 |
@@ -1786,6 +1939,16 @@ static int ssl_parse_server_hello( mbedtls_ssl_context *ssl ) |
| 331 |
break; |
| 332 |
#endif /* MBEDTLS_SSL_ALPN */ |
| 333 |
|
| 334 |
+#if defined(MBEDTLS_SSL_DTLS_SRTP) |
| 335 |
+ case MBEDTLS_TLS_EXT_USE_SRTP: |
| 336 |
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "found use_srtp extension" ) ); |
| 337 |
+ |
| 338 |
+ if( ( ret = ssl_parse_use_srtp_ext( ssl, ext + 4, ext_size ) ) != 0 ) |
| 339 |
+ return( ret ); |
| 340 |
+ |
| 341 |
+ break; |
| 342 |
+#endif /* MBEDTLS_SSL_DTLS_SRTP */ |
| 343 |
+ |
| 344 |
default: |
| 345 |
MBEDTLS_SSL_DEBUG_MSG( 3, ( "unknown extension found: %d (ignoring)", |
| 346 |
ext_id ) ); |
| 347 |
diff --git a/library/ssl_srv.c b/library/ssl_srv.c |
| 348 |
index 6b5b461..72b50ab 100644 |
| 349 |
--- library/ssl_srv.c |
| 350 |
+++ library/ssl_srv.c |
| 351 |
@@ -573,6 +573,78 @@ static int ssl_parse_alpn_ext( mbedtls_ssl_context *ssl, |
| 352 |
} |
| 353 |
#endif /* MBEDTLS_SSL_ALPN */ |
| 354 |
|
| 355 |
+#if defined(MBEDTLS_SSL_DTLS_SRTP) |
| 356 |
+static int ssl_parse_use_srtp_ext( mbedtls_ssl_context *ssl, |
| 357 |
+ const unsigned char *buf, size_t len ) |
| 358 |
+{ |
| 359 |
+ enum mbedtls_DTLS_SRTP_protection_profiles client_protection = MBEDTLS_SRTP_UNSET_PROFILE; |
| 360 |
+ size_t i,j; |
| 361 |
+ uint16_t profile_length; |
| 362 |
+ |
| 363 |
+ /* If use_srtp is not configured, just ignore the extension */ |
| 364 |
+ if( ( ssl->conf->dtls_srtp_profiles_list == NULL ) || ( ssl->conf->dtls_srtp_profiles_list_len == 0 ) ) |
| 365 |
+ return( 0 ); |
| 366 |
+ |
| 367 |
+ /* RFC5764 section 4.1.1 |
| 368 |
+ * uint8 SRTPProtectionProfile[2]; |
| 369 |
+ * |
| 370 |
+ * struct { |
| 371 |
+ * SRTPProtectionProfiles SRTPProtectionProfiles; |
| 372 |
+ * opaque srtp_mki<0..255>; |
| 373 |
+ * } UseSRTPData; |
| 374 |
+ |
| 375 |
+ * SRTPProtectionProfile SRTPProtectionProfiles<2..2^16-1>; |
| 376 |
+ * |
| 377 |
+ * Note: srtp_mki is not supported |
| 378 |
+ */ |
| 379 |
+ |
| 380 |
+ /* Min length is 5 : at least one protection profile(2 bytes) and length(2 bytes) + srtp_mki length(1 byte) */ |
| 381 |
+ if( len < 5 ) |
| 382 |
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| 383 |
+ |
| 384 |
+ /* |
| 385 |
+ * Use our order of preference |
| 386 |
+ */ |
| 387 |
+ profile_length = buf[0]<<8|buf[1]; /* first 2 bytes are protection profile length(in bytes) */ |
| 388 |
+ for( i=0; i < ssl->conf->dtls_srtp_profiles_list_len; i++) |
| 389 |
+ { |
| 390 |
+ /* parse the extension list values are defined in http://www.iana.org/assignments/srtp-protection/srtp-protection.xhtml */ |
| 391 |
+ for (j=0; j<profile_length; j+=2) { /* parse only the protection profile, srtp_mki is not supported and ignored */ |
| 392 |
+ uint16_t protection_profile_value = buf[j+2]<<8 | buf[j+3]; /* +2 to skip the length field */ |
| 393 |
+ |
| 394 |
+ switch ( protection_profile_value ) { |
| 395 |
+ case MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_80_IANA_VALUE: |
| 396 |
+ client_protection = MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_80; |
| 397 |
+ break; |
| 398 |
+ case MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_32_IANA_VALUE: |
| 399 |
+ client_protection = MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_32; |
| 400 |
+ break; |
| 401 |
+ case MBEDTLS_SRTP_NULL_HMAC_SHA1_80_IANA_VALUE: |
| 402 |
+ client_protection = MBEDTLS_SRTP_NULL_HMAC_SHA1_80; |
| 403 |
+ break; |
| 404 |
+ case MBEDTLS_SRTP_NULL_HMAC_SHA1_32_IANA_VALUE: |
| 405 |
+ client_protection = MBEDTLS_SRTP_NULL_HMAC_SHA1_32; |
| 406 |
+ break; |
| 407 |
+ default: |
| 408 |
+ client_protection = MBEDTLS_SRTP_UNSET_PROFILE; |
| 409 |
+ break; |
| 410 |
+ } |
| 411 |
+ |
| 412 |
+ if (client_protection == ssl->conf->dtls_srtp_profiles_list[i]) { |
| 413 |
+ ssl->chosen_dtls_srtp_profile = ssl->conf->dtls_srtp_profiles_list[i]; |
| 414 |
+ return 0; |
| 415 |
+ } |
| 416 |
+ } |
| 417 |
+ } |
| 418 |
+ |
| 419 |
+ /* If we get there, no match was found */ |
| 420 |
+ ssl->chosen_dtls_srtp_profile = MBEDTLS_SRTP_UNSET_PROFILE; |
| 421 |
+ mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL, |
| 422 |
+ MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE ); |
| 423 |
+ return( MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO ); |
| 424 |
+} |
| 425 |
+#endif /* MBEDTLS_SSL_DTLS_SRTP */ |
| 426 |
+ |
| 427 |
/* |
| 428 |
* Auxiliary functions for ServerHello parsing and related actions |
| 429 |
*/ |
| 430 |
@@ -1675,7 +1747,16 @@ read_record_header: |
| 431 |
if( ret != 0 ) |
| 432 |
return( ret ); |
| 433 |
break; |
| 434 |
-#endif /* MBEDTLS_SSL_SESSION_TICKETS */ |
| 435 |
+#endif /* MBEDTLS_SSL_ALPN */ |
| 436 |
+ |
| 437 |
+#if defined(MBEDTLS_SSL_DTLS_SRTP) |
| 438 |
+ case MBEDTLS_TLS_EXT_USE_SRTP: |
| 439 |
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "found use_srtp extension" ) ); |
| 440 |
+ ret = ssl_parse_use_srtp_ext( ssl, ext + 4, ext_size ); |
| 441 |
+ if ( ret != 0) |
| 442 |
+ return( ret ); |
| 443 |
+ break; |
| 444 |
+#endif /* MBEDTLS_SSL_DTLS_SRTP */ |
| 445 |
|
| 446 |
default: |
| 447 |
MBEDTLS_SSL_DEBUG_MSG( 3, ( "unknown extension found: %d (ignoring)", |
| 448 |
@@ -2144,6 +2225,57 @@ static void ssl_write_alpn_ext( mbedtls_ssl_context *ssl, |
| 449 |
} |
| 450 |
#endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C */ |
| 451 |
|
| 452 |
+#if defined(MBEDTLS_SSL_DTLS_SRTP ) |
| 453 |
+static void ssl_write_use_srtp_ext( mbedtls_ssl_context *ssl, |
| 454 |
+ unsigned char *buf, size_t *olen ) |
| 455 |
+{ |
| 456 |
+ if( ssl->chosen_dtls_srtp_profile == MBEDTLS_SRTP_UNSET_PROFILE ) |
| 457 |
+ { |
| 458 |
+ *olen = 0; |
| 459 |
+ return; |
| 460 |
+ } |
| 461 |
+ |
| 462 |
+ MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, adding use_srtp extension" ) ); |
| 463 |
+ |
| 464 |
+ /* extension */ |
| 465 |
+ buf[0] = (unsigned char)( ( MBEDTLS_TLS_EXT_USE_SRTP >> 8 ) & 0xFF ); |
| 466 |
+ buf[1] = (unsigned char)( ( MBEDTLS_TLS_EXT_USE_SRTP ) & 0xFF ); |
| 467 |
+ /* total length (5: only one profile(2 bytes) and length(2bytes) and srtp_mki not supported so zero length(1byte) ) */ |
| 468 |
+ buf[2] = 0x00; |
| 469 |
+ buf[3] = 0x05; |
| 470 |
+ |
| 471 |
+ /* protection profile length: 2 */ |
| 472 |
+ buf[4] = 0x00; |
| 473 |
+ buf[5] = 0x02; |
| 474 |
+ switch (ssl->chosen_dtls_srtp_profile) { |
| 475 |
+ case MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_80: |
| 476 |
+ buf[6] = (unsigned char)( ( MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_80_IANA_VALUE >> 8) & 0xFF ); |
| 477 |
+ buf[7] = (unsigned char)( ( MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_80_IANA_VALUE ) & 0xFF ); |
| 478 |
+ break; |
| 479 |
+ case MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_32: |
| 480 |
+ buf[6] = (unsigned char)( ( MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_32_IANA_VALUE >> 8) & 0xFF ); |
| 481 |
+ buf[7] = (unsigned char)( ( MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_32_IANA_VALUE ) & 0xFF ); |
| 482 |
+ break; |
| 483 |
+ case MBEDTLS_SRTP_NULL_HMAC_SHA1_80: |
| 484 |
+ buf[6] = (unsigned char)( ( MBEDTLS_SRTP_NULL_HMAC_SHA1_80_IANA_VALUE >> 8) & 0xFF ); |
| 485 |
+ buf[7] = (unsigned char)( ( MBEDTLS_SRTP_NULL_HMAC_SHA1_80_IANA_VALUE ) & 0xFF ); |
| 486 |
+ break; |
| 487 |
+ case MBEDTLS_SRTP_NULL_HMAC_SHA1_32: |
| 488 |
+ buf[6] = (unsigned char)( ( MBEDTLS_SRTP_NULL_HMAC_SHA1_32_IANA_VALUE >> 8) & 0xFF ); |
| 489 |
+ buf[7] = (unsigned char)( ( MBEDTLS_SRTP_NULL_HMAC_SHA1_32_IANA_VALUE ) & 0xFF ); |
| 490 |
+ break; |
| 491 |
+ default: |
| 492 |
+ *olen = 0; |
| 493 |
+ return; |
| 494 |
+ break; |
| 495 |
+ } |
| 496 |
+ |
| 497 |
+ buf[8] = 0x00; /* unsupported srtp_mki variable length vector set to 0 */ |
| 498 |
+ |
| 499 |
+ *olen = 9; |
| 500 |
+} |
| 501 |
+#endif /* MBEDTLS_SSL_DTLS_SRTP */ |
| 502 |
+ |
| 503 |
#if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY) |
| 504 |
static int ssl_write_hello_verify_request( mbedtls_ssl_context *ssl ) |
| 505 |
{ |
| 506 |
@@ -2408,6 +2540,11 @@ static int ssl_write_server_hello( mbedtls_ssl_context *ssl ) |
| 507 |
ext_len += olen; |
| 508 |
#endif |
| 509 |
|
| 510 |
+#if defined(MBEDTLS_SSL_DTLS_SRTP) |
| 511 |
+ ssl_write_use_srtp_ext( ssl, p + 2 + ext_len, &olen); |
| 512 |
+ ext_len += olen; |
| 513 |
+#endif |
| 514 |
+ |
| 515 |
MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, total extension length: %d", ext_len ) ); |
| 516 |
|
| 517 |
if( ext_len > 0 ) |
| 518 |
diff --git a/library/ssl_tls.c b/library/ssl_tls.c |
| 519 |
index 4424f56..940f8aa 100644 |
| 520 |
--- library/ssl_tls.c |
| 521 |
+++ library/ssl_tls.c |
| 522 |
@@ -373,7 +373,7 @@ static int tls_prf_generic( mbedtls_md_type_t md_type, |
| 523 |
{ |
| 524 |
size_t nb; |
| 525 |
size_t i, j, k, md_len; |
| 526 |
- unsigned char tmp[128]; |
| 527 |
+ unsigned char tmp[144]; |
| 528 |
unsigned char h_i[MBEDTLS_MD_MAX_SIZE]; |
| 529 |
const mbedtls_md_info_t *md_info; |
| 530 |
mbedtls_md_context_t md_ctx; |
| 531 |
@@ -636,6 +636,30 @@ int mbedtls_ssl_derive_keys( mbedtls_ssl_context *ssl ) |
| 532 |
else |
| 533 |
MBEDTLS_SSL_DEBUG_MSG( 3, ( "no premaster (session resumed)" ) ); |
| 534 |
|
| 535 |
+#if defined(MBEDTLS_SSL_DTLS_SRTP) |
| 536 |
+ /* check if we have a chosen srtp protection profile */ |
| 537 |
+ if (ssl->chosen_dtls_srtp_profile != MBEDTLS_SRTP_UNSET_PROFILE) { |
| 538 |
+ /* derive key material for srtp session RFC5764 section 4.2 */ |
| 539 |
+ /* master key and master salt are respectively 128 bits and 112 bits for all currently available modes : |
| 540 |
+ * SRTP_AES128_CM_HMAC_SHA1_80, SRTP_AES128_CM_HMAC_SHA1_32 |
| 541 |
+ * SRTP_NULL_HMAC_SHA1_80, SRTP_NULL_HMAC_SHA1_32 |
| 542 |
+ * So we must export 2*(128 + 112) = 480 bits |
| 543 |
+ */ |
| 544 |
+ ssl->dtls_srtp_keys_len = 60; |
| 545 |
+ |
| 546 |
+ ssl->dtls_srtp_keys = (unsigned char *)mbedtls_calloc(1, ssl->dtls_srtp_keys_len); |
| 547 |
+ |
| 548 |
+ ret = handshake->tls_prf( session->master, 48, "EXTRACTOR-dtls_srtp", |
| 549 |
+ handshake->randbytes, 64, ssl->dtls_srtp_keys, ssl->dtls_srtp_keys_len ); |
| 550 |
+ |
| 551 |
+ if( ret != 0 ) |
| 552 |
+ { |
| 553 |
+ MBEDTLS_SSL_DEBUG_RET( 1, "dtls srtp prf", ret ); |
| 554 |
+ return( ret ); |
| 555 |
+ } |
| 556 |
+ } |
| 557 |
+#endif /* MBEDTLS_SSL_DTLS_SRTP */ |
| 558 |
+ |
| 559 |
/* |
| 560 |
* Swap the client and server random values. |
| 561 |
*/ |
| 562 |
@@ -5408,6 +5432,12 @@ int mbedtls_ssl_setup( mbedtls_ssl_context *ssl, |
| 563 |
ssl->in_msg = ssl->in_buf + 13; |
| 564 |
} |
| 565 |
|
| 566 |
+#if defined(MBEDTLS_SSL_DTLS_SRTP) |
| 567 |
+ ssl->chosen_dtls_srtp_profile = MBEDTLS_SRTP_UNSET_PROFILE; |
| 568 |
+ ssl->dtls_srtp_keys = NULL; |
| 569 |
+ ssl->dtls_srtp_keys_len = 0; |
| 570 |
+#endif |
| 571 |
+ |
| 572 |
if( ( ret = ssl_handshake_init( ssl ) ) != 0 ) |
| 573 |
return( ret ); |
| 574 |
|
| 575 |
@@ -5997,6 +6027,61 @@ const char *mbedtls_ssl_get_alpn_protocol( const mbedtls_ssl_context *ssl ) |
| 576 |
} |
| 577 |
#endif /* MBEDTLS_SSL_ALPN */ |
| 578 |
|
| 579 |
+#if defined(MBEDTLS_SSL_DTLS_SRTP) |
| 580 |
+int mbedtls_ssl_conf_dtls_srtp_protection_profiles( mbedtls_ssl_config *conf, const enum mbedtls_DTLS_SRTP_protection_profiles *profiles, size_t profiles_number) |
| 581 |
+{ |
| 582 |
+ size_t i; |
| 583 |
+ /* check in put validity : must be a list of profiles from enumeration */ |
| 584 |
+ /* maximum length is 4 as only 4 protection profiles are defined */ |
| 585 |
+ if (profiles_number>4) { |
| 586 |
+ return MBEDTLS_ERR_SSL_BAD_INPUT_DATA; |
| 587 |
+ } |
| 588 |
+ |
| 589 |
+ mbedtls_free(conf->dtls_srtp_profiles_list); |
| 590 |
+ conf->dtls_srtp_profiles_list = (enum mbedtls_DTLS_SRTP_protection_profiles *)mbedtls_calloc(1, profiles_number*sizeof(enum mbedtls_DTLS_SRTP_protection_profiles)); |
| 591 |
+ |
| 592 |
+ for (i=0; i<profiles_number; i++) { |
| 593 |
+ switch (profiles[i]) { |
| 594 |
+ case MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_80: |
| 595 |
+ case MBEDTLS_SRTP_AES128_CM_HMAC_SHA1_32: |
| 596 |
+ case MBEDTLS_SRTP_NULL_HMAC_SHA1_80: |
| 597 |
+ case MBEDTLS_SRTP_NULL_HMAC_SHA1_32: |
| 598 |
+ conf->dtls_srtp_profiles_list[i] = profiles[i]; |
| 599 |
+ break; |
| 600 |
+ default: |
| 601 |
+ mbedtls_free(conf->dtls_srtp_profiles_list); |
| 602 |
+ conf->dtls_srtp_profiles_list = NULL; |
| 603 |
+ conf->dtls_srtp_profiles_list_len = 0; |
| 604 |
+ return MBEDTLS_ERR_SSL_BAD_INPUT_DATA; |
| 605 |
+ } |
| 606 |
+ } |
| 607 |
+ |
| 608 |
+ /* assign array length */ |
| 609 |
+ conf->dtls_srtp_profiles_list_len = profiles_number; |
| 610 |
+ |
| 611 |
+ return( 0 ); |
| 612 |
+} |
| 613 |
+ |
| 614 |
+enum mbedtls_DTLS_SRTP_protection_profiles mbedtls_ssl_get_dtls_srtp_protection_profile( const mbedtls_ssl_context *ssl) |
| 615 |
+{ |
| 616 |
+ return( ssl->chosen_dtls_srtp_profile); |
| 617 |
+} |
| 618 |
+ |
| 619 |
+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 ) { |
| 620 |
+ *key_len = 0; |
| 621 |
+ |
| 622 |
+ /* check output buffer size */ |
| 623 |
+ if ( key_buffer_len < ssl->dtls_srtp_keys_len) { |
| 624 |
+ return MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL; |
| 625 |
+ } |
| 626 |
+ |
| 627 |
+ memcpy( key, ssl->dtls_srtp_keys, ssl->dtls_srtp_keys_len); |
| 628 |
+ *key_len = ssl->dtls_srtp_keys_len; |
| 629 |
+ |
| 630 |
+ return 0; |
| 631 |
+} |
| 632 |
+#endif /* MBEDTLS_SSL_DTLS_SRTP */ |
| 633 |
+ |
| 634 |
void mbedtls_ssl_conf_max_version( mbedtls_ssl_config *conf, int major, int minor ) |
| 635 |
{ |
| 636 |
conf->max_major_ver = major; |
| 637 |
@@ -7083,6 +7169,11 @@ void mbedtls_ssl_free( mbedtls_ssl_context *ssl ) |
| 638 |
mbedtls_free( ssl->cli_id ); |
| 639 |
#endif |
| 640 |
|
| 641 |
+#if defined (MBEDTLS_SSL_DTLS_SRTP) |
| 642 |
+ mbedtls_zeroize( ssl->dtls_srtp_keys, ssl->dtls_srtp_keys_len ); |
| 643 |
+ mbedtls_free( ssl->dtls_srtp_keys ); |
| 644 |
+#endif /* MBEDTLS_SSL_DTLS_SRTP */ |
| 645 |
+ |
| 646 |
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= free" ) ); |
| 647 |
|
| 648 |
/* Actually clear after last debug message */ |
| 649 |
@@ -7311,6 +7402,10 @@ void mbedtls_ssl_config_free( mbedtls_ssl_config *conf ) |
| 650 |
ssl_key_cert_free( conf->key_cert ); |
| 651 |
#endif |
| 652 |
|
| 653 |
+#if defined (MBEDTLS_SSL_DTLS_SRTP) |
| 654 |
+ mbedtls_free( conf->dtls_srtp_profiles_list ); |
| 655 |
+#endif |
| 656 |
+ |
| 657 |
mbedtls_zeroize( conf, sizeof( mbedtls_ssl_config ) ); |
| 658 |
} |
| 659 |
|