Convert the SRTP extension to the new system
Change-Id: I12f1d06562c34d357d82bbde7e5d0c15096046e6
Reviewed-on: https://boringssl-review.googlesource.com/5463
Reviewed-by: Adam Langley <agl@google.com>
diff --git a/include/openssl/tls1.h b/include/openssl/tls1.h
index b3be3e1..b68db3d 100644
--- a/include/openssl/tls1.h
+++ b/include/openssl/tls1.h
@@ -209,7 +209,7 @@
#define TLSEXT_TYPE_signature_algorithms 13
/* ExtensionType value from RFC5764 */
-#define TLSEXT_TYPE_use_srtp 14
+#define TLSEXT_TYPE_srtp 14
/* ExtensionType value from RFC5620 */
#define TLSEXT_TYPE_heartbeat 15
diff --git a/ssl/d1_srtp.c b/ssl/d1_srtp.c
index a698b10..48ecfb2 100644
--- a/ssl/d1_srtp.c
+++ b/ssl/d1_srtp.c
@@ -125,12 +125,12 @@
#include <openssl/srtp.h>
-static const SRTP_PROTECTION_PROFILE srtp_known_profiles[] = {
+const SRTP_PROTECTION_PROFILE kSRTPProfiles[] = {
{
- "SRTP_AES128_CM_SHA1_80", SRTP_AES128_CM_SHA1_80,
+ "SRTP_AES128_CM_SHA1_80", SRTP_AES128_CM_SHA1_80,
},
{
- "SRTP_AES128_CM_SHA1_32", SRTP_AES128_CM_SHA1_32,
+ "SRTP_AES128_CM_SHA1_32", SRTP_AES128_CM_SHA1_32,
},
{0},
};
@@ -140,7 +140,7 @@
size_t len) {
const SRTP_PROTECTION_PROFILE *p;
- p = srtp_known_profiles;
+ p = kSRTPProfiles;
while (p->name) {
if (len == strlen(p->name) && !strncmp(p->name, profile_name, len)) {
*pptr = p;
@@ -153,22 +153,6 @@
return 0;
}
-static int find_profile_by_num(unsigned profile_num,
- const SRTP_PROTECTION_PROFILE **pptr) {
- const SRTP_PROTECTION_PROFILE *p;
-
- p = srtp_known_profiles;
- while (p->name) {
- if (p->id == profile_num) {
- *pptr = p;
- return 1;
- }
- p++;
- }
-
- return 0;
-}
-
static int ssl_ctx_make_profiles(const char *profiles_string,
STACK_OF(SRTP_PROTECTION_PROFILE) **out) {
STACK_OF(SRTP_PROTECTION_PROFILE) *profiles;
@@ -240,181 +224,3 @@
/* This API inverts its return value. */
return !SSL_set_srtp_profiles(s, profiles);
}
-
-/* Note: this function returns 0 length if there are no profiles specified */
-int ssl_add_clienthello_use_srtp_ext(SSL *s, uint8_t *p, int *len, int maxlen) {
- int ct = 0;
- int i;
- STACK_OF(SRTP_PROTECTION_PROFILE) *clnt = 0;
- const SRTP_PROTECTION_PROFILE *prof;
-
- clnt = SSL_get_srtp_profiles(s);
- ct = sk_SRTP_PROTECTION_PROFILE_num(clnt); /* -1 if clnt == 0 */
-
- if (p) {
- if (ct == 0) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_EMPTY_SRTP_PROTECTION_PROFILE_LIST);
- return 0;
- }
-
- if (2 + ct * 2 + 1 > maxlen) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_SRTP_PROTECTION_PROFILE_LIST_TOO_LONG);
- return 0;
- }
-
- /* Add the length */
- s2n(ct * 2, p);
- for (i = 0; i < ct; i++) {
- prof = sk_SRTP_PROTECTION_PROFILE_value(clnt, i);
- s2n(prof->id, p);
- }
-
- /* Add an empty use_mki value */
- *p++ = 0;
- }
-
- *len = 2 + ct * 2 + 1;
-
- return 1;
-}
-
-int ssl_parse_clienthello_use_srtp_ext(SSL *s, CBS *cbs, int *out_alert) {
- CBS profile_ids, srtp_mki;
- const SRTP_PROTECTION_PROFILE *cprof, *sprof;
- STACK_OF(SRTP_PROTECTION_PROFILE) *client_profiles = 0, *server_profiles;
- size_t i, j;
- int ret = 0;
-
- if (!CBS_get_u16_length_prefixed(cbs, &profile_ids) ||
- CBS_len(&profile_ids) < 2 ||
- !CBS_get_u8_length_prefixed(cbs, &srtp_mki) ||
- CBS_len(cbs) != 0) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
- *out_alert = SSL_AD_DECODE_ERROR;
- goto done;
- }
-
- client_profiles = sk_SRTP_PROTECTION_PROFILE_new_null();
- if (client_profiles == NULL) {
- OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
- *out_alert = SSL_AD_INTERNAL_ERROR;
- goto done;
- }
-
- while (CBS_len(&profile_ids) > 0) {
- uint16_t profile_id;
-
- if (!CBS_get_u16(&profile_ids, &profile_id)) {
- *out_alert = SSL_AD_DECODE_ERROR;
- goto done;
- }
-
- if (find_profile_by_num(profile_id, &cprof)) {
- sk_SRTP_PROTECTION_PROFILE_push(client_profiles, cprof);
- }
- }
-
- /* Discard the MKI value for now. */
-
- server_profiles = SSL_get_srtp_profiles(s);
-
- /* Pick the server's most preferred profile. */
- for (i = 0; i < sk_SRTP_PROTECTION_PROFILE_num(server_profiles); i++) {
- sprof = sk_SRTP_PROTECTION_PROFILE_value(server_profiles, i);
-
- for (j = 0; j < sk_SRTP_PROTECTION_PROFILE_num(client_profiles); j++) {
- cprof = sk_SRTP_PROTECTION_PROFILE_value(client_profiles, j);
-
- if (cprof->id == sprof->id) {
- s->srtp_profile = sprof;
- ret = 1;
- goto done;
- }
- }
- }
-
- ret = 1;
-
-done:
- if (client_profiles) {
- sk_SRTP_PROTECTION_PROFILE_free(client_profiles);
- }
-
- return ret;
-}
-
-int ssl_add_serverhello_use_srtp_ext(SSL *s, unsigned char *p, int *len,
- int maxlen) {
- if (p) {
- if (maxlen < 5) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_SRTP_PROTECTION_PROFILE_LIST_TOO_LONG);
- return 0;
- }
-
- if (s->srtp_profile == 0) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_USE_SRTP_NOT_NEGOTIATED);
- return 0;
- }
-
- s2n(2, p);
- s2n(s->srtp_profile->id, p);
- *p++ = 0;
- }
-
- *len = 5;
-
- return 1;
-}
-
-int ssl_parse_serverhello_use_srtp_ext(SSL *s, CBS *cbs, int *out_alert) {
- CBS profile_ids, srtp_mki;
- uint16_t profile_id;
- size_t i;
-
- STACK_OF(SRTP_PROTECTION_PROFILE) *client_profiles;
- const SRTP_PROTECTION_PROFILE *prof;
-
- /* The extension consists of a u16-prefixed profile ID list containing a
- * single uint16_t profile ID, then followed by a u8-prefixed srtp_mki field.
- *
- * See https://tools.ietf.org/html/rfc5764#section-4.1.1 */
- if (!CBS_get_u16_length_prefixed(cbs, &profile_ids) ||
- !CBS_get_u16(&profile_ids, &profile_id) || CBS_len(&profile_ids) != 0 ||
- !CBS_get_u8_length_prefixed(cbs, &srtp_mki) || CBS_len(cbs) != 0) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
- *out_alert = SSL_AD_DECODE_ERROR;
- return 0;
- }
-
- if (CBS_len(&srtp_mki) != 0) {
- /* Must be no MKI, since we never offer one. */
- OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_SRTP_MKI_VALUE);
- *out_alert = SSL_AD_ILLEGAL_PARAMETER;
- return 0;
- }
-
- client_profiles = SSL_get_srtp_profiles(s);
-
- /* Throw an error if the server gave us an unsolicited extension */
- if (client_profiles == NULL) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_NO_SRTP_PROFILES);
- *out_alert = SSL_AD_DECODE_ERROR;
- return 0;
- }
-
- /* Check to see if the server gave us something we support
- (and presumably offered). */
- for (i = 0; i < sk_SRTP_PROTECTION_PROFILE_num(client_profiles); i++) {
- prof = sk_SRTP_PROTECTION_PROFILE_value(client_profiles, i);
-
- if (prof->id == profile_id) {
- s->srtp_profile = prof;
- *out_alert = 0;
- return 1;
- }
- }
-
- OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
- *out_alert = SSL_AD_ILLEGAL_PARAMETER;
- return 0;
-}
diff --git a/ssl/internal.h b/ssl/internal.h
index f107452..1a28245 100644
--- a/ssl/internal.h
+++ b/ssl/internal.h
@@ -1168,9 +1168,4 @@
CBS *cbs, EVP_PKEY *pkey);
void ssl_set_client_disabled(SSL *s);
-int ssl_add_clienthello_use_srtp_ext(SSL *s, uint8_t *p, int *len, int maxlen);
-int ssl_parse_clienthello_use_srtp_ext(SSL *s, CBS *cbs, int *out_alert);
-int ssl_add_serverhello_use_srtp_ext(SSL *s, uint8_t *p, int *len, int maxlen);
-int ssl_parse_serverhello_use_srtp_ext(SSL *s, CBS *cbs, int *out_alert);
-
#endif /* OPENSSL_HEADER_SSL_INTERNAL_H */
diff --git a/ssl/t1_lib.c b/ssl/t1_lib.c
index 4551025..9b64c7b 100644
--- a/ssl/t1_lib.c
+++ b/ssl/t1_lib.c
@@ -1760,6 +1760,160 @@
return 1;
}
+
+/* Secure Real-time Transport Protocol (SRTP) extension.
+ *
+ * https://tools.ietf.org/html/rfc5764 */
+
+extern const SRTP_PROTECTION_PROFILE kSRTPProfiles[];
+
+static void ext_srtp_init(SSL *ssl) {
+ ssl->srtp_profile = NULL;
+}
+
+static int ext_srtp_add_clienthello(SSL *ssl, CBB *out) {
+ STACK_OF(SRTP_PROTECTION_PROFILE) *profiles = SSL_get_srtp_profiles(ssl);
+ if (profiles == NULL) {
+ return 1;
+ }
+ const size_t num_profiles = sk_SRTP_PROTECTION_PROFILE_num(profiles);
+ if (num_profiles == 0) {
+ return 1;
+ }
+
+ CBB contents, profile_ids;
+ if (!CBB_add_u16(out, TLSEXT_TYPE_srtp) ||
+ !CBB_add_u16_length_prefixed(out, &contents) ||
+ !CBB_add_u16_length_prefixed(&contents, &profile_ids)) {
+ return 0;
+ }
+
+ size_t i;
+ for (i = 0; i < num_profiles; i++) {
+ if (!CBB_add_u16(&profile_ids,
+ sk_SRTP_PROTECTION_PROFILE_value(profiles, i)->id)) {
+ return 0;
+ }
+ }
+
+ if (!CBB_add_u8(&contents, 0 /* empty use_mki value */) ||
+ !CBB_flush(out)) {
+ return 0;
+ }
+
+ return 1;
+}
+
+static int ext_srtp_parse_serverhello(SSL *ssl, uint8_t *out_alert,
+ CBS *contents) {
+ if (contents == NULL) {
+ return 1;
+ }
+
+ /* The extension consists of a u16-prefixed profile ID list containing a
+ * single uint16_t profile ID, then followed by a u8-prefixed srtp_mki field.
+ *
+ * See https://tools.ietf.org/html/rfc5764#section-4.1.1 */
+ CBS profile_ids, srtp_mki;
+ uint16_t profile_id;
+ if (!CBS_get_u16_length_prefixed(contents, &profile_ids) ||
+ !CBS_get_u16(&profile_ids, &profile_id) ||
+ CBS_len(&profile_ids) != 0 ||
+ !CBS_get_u8_length_prefixed(contents, &srtp_mki) ||
+ CBS_len(contents) != 0) {
+ OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
+ return 0;
+ }
+
+ if (CBS_len(&srtp_mki) != 0) {
+ /* Must be no MKI, since we never offer one. */
+ OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_SRTP_MKI_VALUE);
+ *out_alert = SSL_AD_ILLEGAL_PARAMETER;
+ return 0;
+ }
+
+ STACK_OF(SRTP_PROTECTION_PROFILE) *profiles = SSL_get_srtp_profiles(ssl);
+
+ /* Check to see if the server gave us something we support (and presumably
+ * offered). */
+ size_t i;
+ for (i = 0; i < sk_SRTP_PROTECTION_PROFILE_num(profiles); i++) {
+ const SRTP_PROTECTION_PROFILE *profile =
+ sk_SRTP_PROTECTION_PROFILE_value(profiles, i);
+
+ if (profile->id == profile_id) {
+ ssl->srtp_profile = profile;
+ return 1;
+ }
+ }
+
+ OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
+ *out_alert = SSL_AD_ILLEGAL_PARAMETER;
+ return 0;
+}
+
+static int ext_srtp_parse_clienthello(SSL *ssl, uint8_t *out_alert,
+ CBS *contents) {
+ if (contents == NULL) {
+ return 1;
+ }
+
+ CBS profile_ids, srtp_mki;
+ if (!CBS_get_u16_length_prefixed(contents, &profile_ids) ||
+ CBS_len(&profile_ids) < 2 ||
+ !CBS_get_u8_length_prefixed(contents, &srtp_mki) ||
+ CBS_len(contents) != 0) {
+ OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
+ return 0;
+ }
+ /* Discard the MKI value for now. */
+
+ const STACK_OF(SRTP_PROTECTION_PROFILE) *server_profiles =
+ SSL_get_srtp_profiles(ssl);
+
+ /* Pick the server's most preferred profile. */
+ size_t i;
+ for (i = 0; i < sk_SRTP_PROTECTION_PROFILE_num(server_profiles); i++) {
+ const SRTP_PROTECTION_PROFILE *server_profile =
+ sk_SRTP_PROTECTION_PROFILE_value(server_profiles, i);
+
+ CBS profile_ids_tmp;
+ CBS_init(&profile_ids_tmp, CBS_data(&profile_ids), CBS_len(&profile_ids));
+
+ while (CBS_len(&profile_ids_tmp) > 0) {
+ uint16_t profile_id;
+ if (!CBS_get_u16(&profile_ids_tmp, &profile_id)) {
+ return 0;
+ }
+
+ if (server_profile->id == profile_id) {
+ ssl->srtp_profile = server_profile;
+ return 1;
+ }
+ }
+ }
+
+ return 1;
+}
+
+static int ext_srtp_add_serverhello(SSL *ssl, CBB *out) {
+ if (ssl->srtp_profile == NULL) {
+ return 1;
+ }
+
+ CBB contents, profile_ids;
+ if (!CBB_add_u16(out, TLSEXT_TYPE_srtp) ||
+ !CBB_add_u16_length_prefixed(out, &contents) ||
+ !CBB_add_u16_length_prefixed(&contents, &profile_ids) ||
+ !CBB_add_u16(&profile_ids, ssl->srtp_profile->id) ||
+ !CBB_add_u8(&contents, 0 /* empty MKI */) ||
+ !CBB_flush(out)) {
+ return 0;
+ }
+
+ return 1;
+}
+
/* kExtensions contains all the supported extensions. */
static const struct tls_extension kExtensions[] = {
{
@@ -1845,6 +1999,14 @@
ext_channel_id_parse_clienthello,
ext_channel_id_add_serverhello,
},
+ {
+ TLSEXT_TYPE_srtp,
+ ext_srtp_init,
+ ext_srtp_add_clienthello,
+ ext_srtp_parse_serverhello,
+ ext_srtp_parse_clienthello,
+ ext_srtp_add_serverhello,
+ },
};
#define kNumExtensions (sizeof(kExtensions) / sizeof(struct tls_extension))
@@ -1941,25 +2103,6 @@
ret += CBB_len(&cbb);
CBB_cleanup(&cbb);
- if (SSL_get_srtp_profiles(s)) {
- int el;
-
- ssl_add_clienthello_use_srtp_ext(s, 0, &el, 0);
-
- if ((limit - ret - 4 - el) < 0) {
- return NULL;
- }
-
- s2n(TLSEXT_TYPE_use_srtp, ret);
- s2n(el, ret);
-
- if (!ssl_add_clienthello_use_srtp_ext(s, ret, &el, el)) {
- OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
- return NULL;
- }
- ret += el;
- }
-
if (using_ecc) {
/* Add TLS extension ECPointFormats to the ClientHello message */
long lenmax;
@@ -2133,25 +2276,6 @@
}
/* Currently the server should not respond with a SupportedCurves extension */
- if (s->srtp_profile) {
- int el;
-
- ssl_add_serverhello_use_srtp_ext(s, 0, &el, 0);
-
- if ((limit - ret - 4 - el) < 0) {
- return NULL;
- }
-
- s2n(TLSEXT_TYPE_use_srtp, ret);
- s2n(el, ret);
-
- if (!ssl_add_serverhello_use_srtp_ext(s, ret, &el, el)) {
- OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
- return NULL;
- }
- ret += el;
- }
-
extdatalen = ret - orig - 2;
if (extdatalen == 0) {
return orig;
@@ -2164,8 +2288,6 @@
static int ssl_scan_clienthello_tlsext(SSL *s, CBS *cbs, int *out_alert) {
CBS extensions;
- s->srtp_profile = NULL;
-
/* Clear ECC extensions */
OPENSSL_free(s->s3->tmp.peer_ecpointformatlist);
s->s3->tmp.peer_ecpointformatlist = NULL;
@@ -2278,10 +2400,6 @@
}
s->s3->tmp.peer_ellipticcurvelist_length = num_curves;
- } else if (type == TLSEXT_TYPE_use_srtp) {
- if (!ssl_parse_clienthello_use_srtp_ext(s, &extension, out_alert)) {
- return 0;
- }
}
}
@@ -2319,11 +2437,6 @@
static int ssl_scan_serverhello_tlsext(SSL *s, CBS *cbs, int *out_alert) {
CBS extensions;
- /* TODO(davidben): Move all of these to some per-handshake state that gets
- * systematically reset on a new handshake; perhaps allocate it fresh each
- * time so it's not even kept around post-handshake. */
- s->srtp_profile = NULL;
-
/* Clear ECC extensions */
OPENSSL_free(s->s3->tmp.peer_ecpointformatlist);
s->s3->tmp.peer_ecpointformatlist = NULL;
@@ -2397,10 +2510,6 @@
*out_alert = SSL_AD_INTERNAL_ERROR;
return 0;
}
- } else if (type == TLSEXT_TYPE_use_srtp) {
- if (!ssl_parse_serverhello_use_srtp_ext(s, &extension, out_alert)) {
- return 0;
- }
}
}
