Rewrite SRTP extension using CBB/CBS and the new extension framework.

input + ok beck@, jsing@

5 files changed, 250 insertions, 274 deletions

diff --git a/src/lib/libssl/d1_srtp.c b/src/lib/libssl/d1_srtp.c
index 26c14543fc..eb1877a12c 100644
--- a/src/lib/libssl/d1_srtp.c
+++ b/src/lib/libssl/d1_srtp.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: d1_srtp.c,v 1.21 2017/02/07 02:08:38 beck Exp $ */
+/* $OpenBSD: d1_srtp.c,v 1.22 2017/08/27 02:58:04 doug Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -138,8 +138,8 @@ static SRTP_PROTECTION_PROFILE srtp_known_profiles[] = {
         {0}
 };
 
-static int
-find_profile_by_name(char *profile_name, SRTP_PROTECTION_PROFILE **pptr,
+int
+srtp_find_profile_by_name(char *profile_name, SRTP_PROTECTION_PROFILE **pptr,
     unsigned len)
 {
         SRTP_PROTECTION_PROFILE *p;
@@ -158,8 +158,8 @@ find_profile_by_name(char *profile_name, SRTP_PROTECTION_PROFILE **pptr,
         return 1;
 }
 
-static int
-find_profile_by_num(unsigned profile_num, SRTP_PROTECTION_PROFILE **pptr)
+int
+srtp_find_profile_by_num(unsigned profile_num, SRTP_PROTECTION_PROFILE **pptr)
 {
         SRTP_PROTECTION_PROFILE *p;
 
@@ -194,7 +194,7 @@ ssl_ctx_make_profiles(const char *profiles_string,
         do {
                 col = strchr(ptr, ':');
 
-                if (!find_profile_by_name(ptr, &p,
+                if (!srtp_find_profile_by_name(ptr, &p,
                     col ? col - ptr : (int)strlen(ptr))) {
                         sk_SRTP_PROTECTION_PROFILE_push(profiles, p);
                 } else {
@@ -246,212 +246,4 @@ SSL_get_selected_srtp_profile(SSL *s)
         return s->internal->srtp_profile;
 }
 
-/* Note: this function returns 0 length if there are no
-   profiles specified */
-int
-ssl_add_clienthello_use_srtp_ext(SSL *s, unsigned char *p, int *len, int maxlen)
-{
-        int ct = 0;
-        int i;
-        STACK_OF(SRTP_PROTECTION_PROFILE) *clnt = 0;
-        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) {
-                        SSLerror(s, SSL_R_EMPTY_SRTP_PROTECTION_PROFILE_LIST);
-                        return 1;
-                }
-
-                if ((2 + ct * 2 + 1) > maxlen) {
-                        SSLerror(s, SSL_R_SRTP_PROTECTION_PROFILE_LIST_TOO_LONG);
-                        return 1;
-                }
-
-                /* 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 0;
-}
-
-
-int
-ssl_parse_clienthello_use_srtp_ext(SSL *s, const unsigned char *d, int len,
-    int *al)
-{
-        SRTP_PROTECTION_PROFILE *cprof, *sprof;
-        STACK_OF(SRTP_PROTECTION_PROFILE) *clnt = 0, *srvr;
-        int i, j;
-        int ret = 1;
-        uint16_t id;
-        CBS cbs, ciphers, mki;
-
-        if (len < 0) {
-                SSLerror(s, SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
-                *al = SSL_AD_DECODE_ERROR;
-                goto done;
-        }
-
-        CBS_init(&cbs, d, len);
-        /* Pull off the cipher suite list */
-        if (!CBS_get_u16_length_prefixed(&cbs, &ciphers) ||
-            CBS_len(&ciphers) % 2) {
-                SSLerror(s, SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
-                *al = SSL_AD_DECODE_ERROR;
-                goto done;
-        }
-
-        clnt = sk_SRTP_PROTECTION_PROFILE_new_null();
-
-        while (CBS_len(&ciphers) > 0) {
-                if (!CBS_get_u16(&ciphers, &id)) {
-                        SSLerror(s, SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
-                        *al = SSL_AD_DECODE_ERROR;
-                        goto done;
-                }
-
-                if (!find_profile_by_num(id, &cprof))
-                        sk_SRTP_PROTECTION_PROFILE_push(clnt, cprof);
-                else
-                        ; /* Ignore */
-        }
-
-        /* Extract the MKI value as a sanity check, but discard it for now. */
-        if (!CBS_get_u8_length_prefixed(&cbs, &mki) ||
-            CBS_len(&cbs) != 0) {
-                SSLerror(s, SSL_R_BAD_SRTP_MKI_VALUE);
-                *al = SSL_AD_DECODE_ERROR;
-                goto done;
-        }
-
-        srvr = SSL_get_srtp_profiles(s);
-
-        /*
-         * Pick our most preferred profile. If no profiles have been
-         * configured then the outer loop doesn't run
-         * (sk_SRTP_PROTECTION_PROFILE_num() = -1)
-         * and so we just return without doing anything.
-         */
-        for (i = 0; i < sk_SRTP_PROTECTION_PROFILE_num(srvr); i++) {
-                sprof = sk_SRTP_PROTECTION_PROFILE_value(srvr, i);
-
-                for (j = 0; j < sk_SRTP_PROTECTION_PROFILE_num(clnt); j++) {
-                        cprof = sk_SRTP_PROTECTION_PROFILE_value(clnt, j);
-
-                        if (cprof->id == sprof->id) {
-                                s->internal->srtp_profile = sprof;
-                                *al = 0;
-                                ret = 0;
-                                goto done;
-                        }
-                }
-        }
-
-        ret = 0;
-
-done:
-        sk_SRTP_PROTECTION_PROFILE_free(clnt);
-
-        return ret;
-}
-
-int
-ssl_add_serverhello_use_srtp_ext(SSL *s, unsigned char *p, int *len, int maxlen)
-{
-        if (p) {
-                if (maxlen < 5) {
-                        SSLerror(s, SSL_R_SRTP_PROTECTION_PROFILE_LIST_TOO_LONG);
-                        return 1;
-                }
-
-                if (s->internal->srtp_profile == 0) {
-                        SSLerror(s, SSL_R_USE_SRTP_NOT_NEGOTIATED);
-                        return 1;
-                }
-                s2n(2, p);
-                s2n(s->internal->srtp_profile->id, p);
-                *p++ = 0;
-        }
-        *len = 5;
-
-        return 0;
-}
-
-
-int
-ssl_parse_serverhello_use_srtp_ext(SSL *s, const unsigned char *d, int len, int *al)
-{
-        STACK_OF(SRTP_PROTECTION_PROFILE) *clnt;
-        SRTP_PROTECTION_PROFILE *prof;
-        int i;
-        uint16_t id;
-        CBS cbs, profile_ids, mki;
-
-        if (len < 0) {
-                SSLerror(s, SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
-                *al = SSL_AD_DECODE_ERROR;
-                return 1;
-        }
-
-        CBS_init(&cbs, d, len);
-
-        /*
-         * As per RFC 5764 section 4.1.1, server response MUST be a single
-         * profile id.
-         */
-        if (!CBS_get_u16_length_prefixed(&cbs, &profile_ids) ||
-            !CBS_get_u16(&profile_ids, &id) || CBS_len(&profile_ids) != 0) {
-                SSLerror(s, SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
-                *al = SSL_AD_DECODE_ERROR;
-                return 1;
-        }
-
-        /* Must be no MKI, since we never offer one. */
-        if (!CBS_get_u8_length_prefixed(&cbs, &mki) || CBS_len(&mki) != 0) {
-                SSLerror(s, SSL_R_BAD_SRTP_MKI_VALUE);
-                *al = SSL_AD_ILLEGAL_PARAMETER;
-                return 1;
-        }
-
-        clnt = SSL_get_srtp_profiles(s);
-
-        /* Throw an error if the server gave us an unsolicited extension. */
-        if (clnt == NULL) {
-                SSLerror(s, SSL_R_NO_SRTP_PROFILES);
-                *al = SSL_AD_DECODE_ERROR;
-                return 1;
-        }
-
-        /*
-         * Check to see if the server gave us something we support
-         * (and presumably offered).
-         */
-        for (i = 0; i < sk_SRTP_PROTECTION_PROFILE_num(clnt); i++) {
-                prof = sk_SRTP_PROTECTION_PROFILE_value(clnt, i);
-
-                if (prof->id == id) {
-                        s->internal->srtp_profile = prof;
-                        *al = 0;
-                        return 0;
-                }
-        }
-
-        SSLerror(s, SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
-        *al = SSL_AD_DECODE_ERROR;
-        return 1;
-}
-
 #endif
diff --git a/src/lib/libssl/ssl_locl.h b/src/lib/libssl/ssl_locl.h
index 624df9c929..e789a4ae27 100644
--- a/src/lib/libssl/ssl_locl.h
+++ b/src/lib/libssl/ssl_locl.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_locl.h,v 1.191 2017/08/26 20:23:46 doug Exp $ */
+/* $OpenBSD: ssl_locl.h,v 1.192 2017/08/27 02:58:04 doug Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -1348,6 +1348,15 @@ void tls1_get_formatlist(SSL *s, int client_formats, const uint8_t **pformats,
 void tls1_get_curvelist(SSL *s, int client_curves, const uint16_t **pcurves,
     size_t *pcurveslen);
 
+#ifndef OPENSSL_NO_SRTP
+
+int srtp_find_profile_by_name(char *profile_name,
+    SRTP_PROTECTION_PROFILE **pptr, unsigned len);
+int srtp_find_profile_by_num(unsigned profile_num,
+    SRTP_PROTECTION_PROFILE **pptr);
+
+#endif /* OPENSSL_NO_SRTP */
+
 __END_HIDDEN_DECLS
 
 #endif
diff --git a/src/lib/libssl/ssl_tlsext.c b/src/lib/libssl/ssl_tlsext.c
index 405882c0e9..2438b90d04 100644
--- a/src/lib/libssl/ssl_tlsext.c
+++ b/src/lib/libssl/ssl_tlsext.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_tlsext.c,v 1.11 2017/08/26 20:23:46 doug Exp $ */
+/* $OpenBSD: ssl_tlsext.c,v 1.12 2017/08/27 02:58:04 doug Exp $ */
 /*
  * Copyright (c) 2016, 2017 Joel Sing <jsing@openbsd.org>
  * Copyright (c) 2017 Doug Hogan <doug@openbsd.org>
@@ -704,6 +704,7 @@ tlsext_sni_serverhello_parse(SSL *s, CBS *cbs, int *alert)
         return 1;
 }
 
+
 /*
  *Certificate Status Request - RFC 6066 section 8.
  */
@@ -983,6 +984,216 @@ tlsext_sessionticket_serverhello_parse(SSL *s, CBS *cbs, int *alert)
         return 1;
 }
 
+/*
+ * DTLS extension for SRTP key establishment - RFC 5764
+ */
+
+#ifndef OPENSSL_NO_SRTP
+
+int
+tlsext_srtp_clienthello_needs(SSL *s)
+{
+        return SSL_IS_DTLS(s) && SSL_get_srtp_profiles(s) != NULL;
+}
+
+int
+tlsext_srtp_clienthello_build(SSL *s, CBB *cbb)
+{
+        CBB profiles, mki;
+        int ct, i;
+        STACK_OF(SRTP_PROTECTION_PROFILE) *clnt = NULL;
+        SRTP_PROTECTION_PROFILE *prof;
+
+        if ((clnt = SSL_get_srtp_profiles(s)) == NULL) {
+                SSLerror(s, SSL_R_EMPTY_SRTP_PROTECTION_PROFILE_LIST);
+                return 0;
+        }
+
+        if ((ct = sk_SRTP_PROTECTION_PROFILE_num(clnt)) < 1) {
+                SSLerror(s, SSL_R_EMPTY_SRTP_PROTECTION_PROFILE_LIST);
+                return 0;
+        }
+
+        if (!CBB_add_u16_length_prefixed(cbb, &profiles))
+                return 0;
+
+        for (i = 0; i < ct; i++) {
+                if ((prof = sk_SRTP_PROTECTION_PROFILE_value(clnt, i)) == NULL)
+                        return 0;
+                if (!CBB_add_u16(&profiles, prof->id))
+                        return 0;
+        }
+
+        if (!CBB_add_u8_length_prefixed(cbb, &mki))
+                return 0;
+
+        if (!CBB_flush(cbb))
+                return 0;
+
+        return 1;
+}
+
+int
+tlsext_srtp_clienthello_parse(SSL *s, CBS *cbs, int *alert)
+{
+        SRTP_PROTECTION_PROFILE *cprof, *sprof;
+        STACK_OF(SRTP_PROTECTION_PROFILE) *clnt = NULL, *srvr;
+        int i, j;
+        int ret;
+        uint16_t id;
+        CBS profiles, mki;
+
+        ret = 0;
+
+        if (!CBS_get_u16_length_prefixed(cbs, &profiles))
+                goto err;
+        if (CBS_len(&profiles) == 0 || CBS_len(&profiles) % 2 != 0)
+                goto err;
+
+        if ((clnt = sk_SRTP_PROTECTION_PROFILE_new_null()) == NULL)
+                goto err;
+
+        while (CBS_len(&profiles) > 0) {
+                if (!CBS_get_u16(&profiles, &id))
+                        goto err;
+
+                if (!srtp_find_profile_by_num(id, &cprof)) {
+                        if (!sk_SRTP_PROTECTION_PROFILE_push(clnt, cprof))
+                                goto err;
+                }
+        }
+
+        if (!CBS_get_u8_length_prefixed(cbs, &mki) || CBS_len(&mki) != 0) {
+                SSLerror(s, SSL_R_BAD_SRTP_MKI_VALUE);
+                *alert = SSL_AD_DECODE_ERROR;
+                goto done;
+        }
+        if (CBS_len(cbs) != 0)
+                goto err;
+
+        /*
+         * Per RFC 5764 section 4.1.1
+         *
+         * Find the server preferred profile using the client's list.
+         *
+         * The server MUST send a profile if it sends the use_srtp
+         * extension.  If one is not found, it should fall back to the
+         * negotiated DTLS cipher suite or return a DTLS alert.
+         */
+        if ((srvr = SSL_get_srtp_profiles(s)) == NULL)
+                goto err;
+        for (i = 0; i < sk_SRTP_PROTECTION_PROFILE_num(srvr); i++) {
+                if ((sprof = sk_SRTP_PROTECTION_PROFILE_value(srvr, i))
+                    == NULL)
+                        goto err;
+
+                for (j = 0; j < sk_SRTP_PROTECTION_PROFILE_num(clnt); j++) {
+                        if ((cprof = sk_SRTP_PROTECTION_PROFILE_value(clnt, j))
+                            == NULL)
+                                goto err;
+
+                        if (cprof->id == sprof->id) {
+                                s->internal->srtp_profile = sprof;
+                                ret = 1;
+                                goto done;
+                        }
+                }
+        }
+
+        /* If we didn't find anything, fall back to the negotiated */
+        ret = 1;
+        goto done;
+
+ err:
+        SSLerror(s, SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
+        *alert = SSL_AD_DECODE_ERROR;
+
+ done:
+        sk_SRTP_PROTECTION_PROFILE_free(clnt);
+        return ret;
+}
+
+int
+tlsext_srtp_serverhello_needs(SSL *s)
+{
+        return SSL_IS_DTLS(s) && SSL_get_selected_srtp_profile(s) != NULL;
+}
+
+int
+tlsext_srtp_serverhello_build(SSL *s, CBB *cbb)
+{
+        SRTP_PROTECTION_PROFILE *profile;
+        CBB srtp, mki;
+
+        if (!CBB_add_u16_length_prefixed(cbb, &srtp))
+                return 0;
+
+        if ((profile = SSL_get_selected_srtp_profile(s)) == NULL)
+                return 0;
+
+        if (!CBB_add_u16(&srtp, profile->id))
+                return 0;
+
+        if (!CBB_add_u8_length_prefixed(cbb, &mki))
+                return 0;
+
+        if (!CBB_flush(cbb))
+                return 0;
+
+        return 1;
+}
+
+int
+tlsext_srtp_serverhello_parse(SSL *s, CBS *cbs, int *alert)
+{
+        STACK_OF(SRTP_PROTECTION_PROFILE) *clnt;
+        SRTP_PROTECTION_PROFILE *prof;
+        int i;
+        uint16_t id;
+        CBS profile_ids, mki;
+
+        if (!CBS_get_u16_length_prefixed(cbs, &profile_ids)) {
+                SSLerror(s, SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
+                goto err;
+        }
+
+        if (!CBS_get_u16(&profile_ids, &id) || CBS_len(&profile_ids) != 0) {
+                SSLerror(s, SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
+                goto err;
+        }
+
+        if (!CBS_get_u8_length_prefixed(cbs, &mki) || CBS_len(&mki) != 0) {
+                SSLerror(s, SSL_R_BAD_SRTP_MKI_VALUE);
+                *alert = SSL_AD_ILLEGAL_PARAMETER;
+                return 0;
+        }
+
+        if ((clnt = SSL_get_srtp_profiles(s)) == NULL) {
+                SSLerror(s, SSL_R_NO_SRTP_PROFILES);
+                goto err;
+        }
+
+        for (i = 0; i < sk_SRTP_PROTECTION_PROFILE_num(clnt); i++) {
+                if ((prof = sk_SRTP_PROTECTION_PROFILE_value(clnt, i))
+                    == NULL) {
+                        SSLerror(s, SSL_R_NO_SRTP_PROFILES);
+                        goto err;
+                }
+
+                if (prof->id == id) {
+                        s->internal->srtp_profile = prof;
+                        return 1;
+                }
+        }
+
+        SSLerror(s, SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
+ err:
+        *alert = SSL_AD_DECODE_ERROR;
+        return 0;
+}
+
+#endif /* OPENSSL_NO_SRTP */
+
 struct tls_extension {
         uint16_t type;
         int (*clienthello_needs)(SSL *s);
@@ -1066,6 +1277,17 @@ static struct tls_extension tls_extensions[] = {
                 .serverhello_build = tlsext_alpn_serverhello_build,
                 .serverhello_parse = tlsext_alpn_serverhello_parse,
         },
+#ifndef OPENSSL_NO_SRTP
+        {
+                .type = TLSEXT_TYPE_use_srtp,
+                .clienthello_needs = tlsext_srtp_clienthello_needs,
+                .clienthello_build = tlsext_srtp_clienthello_build,
+                .clienthello_parse = tlsext_srtp_clienthello_parse,
+                .serverhello_needs = tlsext_srtp_serverhello_needs,
+                .serverhello_build = tlsext_srtp_serverhello_build,
+                .serverhello_parse = tlsext_srtp_serverhello_parse,
+        }
+#endif /* OPENSSL_NO_SRTP */
 };
 
 #define N_TLS_EXTENSIONS (sizeof(tls_extensions) / sizeof(*tls_extensions))
diff --git a/src/lib/libssl/ssl_tlsext.h b/src/lib/libssl/ssl_tlsext.h
index 21f9bb1bf9..7c6250a7f7 100644
--- a/src/lib/libssl/ssl_tlsext.h
+++ b/src/lib/libssl/ssl_tlsext.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_tlsext.h,v 1.9 2017/08/26 20:23:46 doug Exp $ */
+/* $OpenBSD: ssl_tlsext.h,v 1.10 2017/08/27 02:58:04 doug Exp $ */
 /*
  * Copyright (c) 2016, 2017 Joel Sing <jsing@openbsd.org>
  * Copyright (c) 2017 Doug Hogan <doug@openbsd.org>
@@ -72,6 +72,15 @@ int tlsext_sessionticket_serverhello_needs(SSL *s);
 int tlsext_sessionticket_serverhello_build(SSL *s, CBB *cbb);
 int tlsext_sessionticket_serverhello_parse(SSL *s, CBS *cbs, int *alert);
 
+#ifndef OPENSSL_NO_SRTP
+int tlsext_srtp_clienthello_needs(SSL *s);
+int tlsext_srtp_clienthello_build(SSL *s, CBB *cbb);
+int tlsext_srtp_clienthello_parse(SSL *s, CBS *cbs, int *alert);
+int tlsext_srtp_serverhello_needs(SSL *s);
+int tlsext_srtp_serverhello_build(SSL *s, CBB *cbb);
+int tlsext_srtp_serverhello_parse(SSL *s, CBS *cbs, int *alert);
+#endif
+
 int tlsext_clienthello_build(SSL *s, CBB *cbb);
 int tlsext_clienthello_parse_one(SSL *s, CBS *cbs, uint16_t tlsext_type,
     int *alert);
diff --git a/src/lib/libssl/t1_lib.c b/src/lib/libssl/t1_lib.c
index eb1d96cc11..a9f10166fe 100644
--- a/src/lib/libssl/t1_lib.c
+++ b/src/lib/libssl/t1_lib.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: t1_lib.c,v 1.135 2017/08/26 20:23:46 doug Exp $ */
+/* $OpenBSD: t1_lib.c,v 1.136 2017/08/27 02:58:04 doug Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -687,26 +687,6 @@ ssl_add_clienthello_tlsext(SSL *s, unsigned char *p, unsigned char *limit)
                 return NULL;
         ret += len;
 
-#ifndef OPENSSL_NO_SRTP
-        if (SSL_IS_DTLS(s) && SSL_get_srtp_profiles(s)) {
-                int el;
-
-                ssl_add_clienthello_use_srtp_ext(s, 0, &el, 0);
-
-                if ((size_t)(limit - ret) < 4 + el)
-                        return NULL;
-
-                s2n(TLSEXT_TYPE_use_srtp, ret);
-                s2n(el, ret);
-
-                if (ssl_add_clienthello_use_srtp_ext(s, ret, &el, el)) {
-                        SSLerror(s, ERR_R_INTERNAL_ERROR);
-                        return NULL;
-                }
-                ret += el;
-        }
-#endif
-
         if ((extdatalen = ret - p - 2) == 0)
                 return p;
 
@@ -745,26 +725,6 @@ ssl_add_serverhello_tlsext(SSL *s, unsigned char *p, unsigned char *limit)
          * extension.
          */
 
-#ifndef OPENSSL_NO_SRTP
-        if (SSL_IS_DTLS(s) && s->internal->srtp_profile) {
-                int el;
-
-                ssl_add_serverhello_use_srtp_ext(s, 0, &el, 0);
-
-                if ((size_t)(limit - ret) < 4 + el)
-                        return NULL;
-
-                s2n(TLSEXT_TYPE_use_srtp, ret);
-                s2n(el, ret);
-
-                if (ssl_add_serverhello_use_srtp_ext(s, ret, &el, el)) {
-                        SSLerror(s, ERR_R_INTERNAL_ERROR);
-                        return NULL;
-                }
-                ret += el;
-        }
-#endif
-
         if ((extdatalen = ret - p - 2) == 0)
                 return p;
 
@@ -815,14 +775,6 @@ ssl_parse_clienthello_tlsext(SSL *s, unsigned char **p, unsigned char *d,
                 if (!tlsext_clienthello_parse_one(s, &cbs, type, al))
                         return 0;
 
-                /* session ticket processed earlier */
-#ifndef OPENSSL_NO_SRTP
-                else if (SSL_IS_DTLS(s) && type == TLSEXT_TYPE_use_srtp) {
-                        if (ssl_parse_clienthello_use_srtp_ext(s, data, size, al))
-                                return 0;
-                }
-#endif
-
                 data += size;
         }
 
@@ -888,14 +840,6 @@ ssl_parse_serverhello_tlsext(SSL *s, unsigned char **p, size_t n, int *al)
                 if (!tlsext_serverhello_parse_one(s, &cbs, type, al))
                         return 0;
 
-#ifndef OPENSSL_NO_SRTP
-                else if (SSL_IS_DTLS(s) && type == TLSEXT_TYPE_use_srtp) {
-                        if (ssl_parse_serverhello_use_srtp_ext(s, data,
-                            size, al))
-                                return 0;
-                }
-#endif
-
                 data += size;
 
         }