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/*
* Copyright 2011-2016 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
/*
* DTLS code by Eric Rescorla <ekr@rtfm.com>
*
* Copyright (C) 2006, Network Resonance, Inc. Copyright (C) 2011, RTFM, Inc.
*/
#include <stdio.h>
#include <openssl/objects.h>
#include "ssl_locl.h"
#ifndef OPENSSL_NO_SRTP
static SRTP_PROTECTION_PROFILE srtp_known_profiles[] = {
{
"SRTP_AES128_CM_SHA1_80",
SRTP_AES128_CM_SHA1_80,
},
{
"SRTP_AES128_CM_SHA1_32",
SRTP_AES128_CM_SHA1_32,
},
{
"SRTP_AEAD_AES_128_GCM",
SRTP_AEAD_AES_128_GCM,
},
{
"SRTP_AEAD_AES_256_GCM",
SRTP_AEAD_AES_256_GCM,
},
{0}
};
static int find_profile_by_name(char *profile_name,
SRTP_PROTECTION_PROFILE **pptr, unsigned len)
{
SRTP_PROTECTION_PROFILE *p;
p = srtp_known_profiles;
while (p->name) {
if ((len == strlen(p->name))
&& strncmp(p->name, profile_name, len) == 0) {
*pptr = p;
return 0;
}
p++;
}
return 1;
}
static int ssl_ctx_make_profiles(const char *profiles_string,
STACK_OF(SRTP_PROTECTION_PROFILE) **out)
{
STACK_OF(SRTP_PROTECTION_PROFILE) *profiles;
char *col;
char *ptr = (char *)profiles_string;
SRTP_PROTECTION_PROFILE *p;
if ((profiles = sk_SRTP_PROTECTION_PROFILE_new_null()) == NULL) {
SSLerr(SSL_F_SSL_CTX_MAKE_PROFILES,
SSL_R_SRTP_COULD_NOT_ALLOCATE_PROFILES);
return 1;
}
do {
col = strchr(ptr, ':');
if (!find_profile_by_name(ptr, &p, col ? col - ptr : (int)strlen(ptr))) {
if (sk_SRTP_PROTECTION_PROFILE_find(profiles, p) >= 0) {
SSLerr(SSL_F_SSL_CTX_MAKE_PROFILES,
SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
goto err;
}
if (!sk_SRTP_PROTECTION_PROFILE_push(profiles, p)) {
SSLerr(SSL_F_SSL_CTX_MAKE_PROFILES,
SSL_R_SRTP_COULD_NOT_ALLOCATE_PROFILES);
goto err;
}
} else {
SSLerr(SSL_F_SSL_CTX_MAKE_PROFILES,
SSL_R_SRTP_UNKNOWN_PROTECTION_PROFILE);
goto err;
}
if (col)
ptr = col + 1;
} while (col);
sk_SRTP_PROTECTION_PROFILE_free(*out);
*out = profiles;
return 0;
err:
sk_SRTP_PROTECTION_PROFILE_free(profiles);
return 1;
}
int SSL_CTX_set_tlsext_use_srtp(SSL_CTX *ctx, const char *profiles)
{
return ssl_ctx_make_profiles(profiles, &ctx->srtp_profiles);
}
int SSL_set_tlsext_use_srtp(SSL *s, const char *profiles)
{
return ssl_ctx_make_profiles(profiles, &s->srtp_profiles);
}
STACK_OF(SRTP_PROTECTION_PROFILE) *SSL_get_srtp_profiles(SSL *s)
{
if (s != NULL) {
if (s->srtp_profiles != NULL) {
return s->srtp_profiles;
} else if ((s->ctx != NULL) && (s->ctx->srtp_profiles != NULL)) {
return s->ctx->srtp_profiles;
}
}
return NULL;
}
SRTP_PROTECTION_PROFILE *SSL_get_selected_srtp_profile(SSL *s)
{
return s->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) {
SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_USE_SRTP_EXT,
SSL_R_EMPTY_SRTP_PROTECTION_PROFILE_LIST);
return 1;
}
if ((2 + ct * 2 + 1) > maxlen) {
SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_USE_SRTP_EXT,
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, PACKET *pkt, int *al)
{
SRTP_PROTECTION_PROFILE *sprof;
STACK_OF(SRTP_PROTECTION_PROFILE) *srvr;
unsigned int ct, mki_len, id;
int i, srtp_pref;
PACKET subpkt;
/* Pull off the length of the cipher suite list and check it is even */
if (!PACKET_get_net_2(pkt, &ct)
|| (ct & 1) != 0 || !PACKET_get_sub_packet(pkt, &subpkt, ct)) {
SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT,
SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
*al = SSL_AD_DECODE_ERROR;
return 1;
}
srvr = SSL_get_srtp_profiles(s);
s->srtp_profile = NULL;
/* Search all profiles for a match initially */
srtp_pref = sk_SRTP_PROTECTION_PROFILE_num(srvr);
while (PACKET_remaining(&subpkt)) {
if (!PACKET_get_net_2(&subpkt, &id)) {
SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT,
SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
*al = SSL_AD_DECODE_ERROR;
return 1;
}
/*
* Only look for match in profiles of higher preference than
* current match.
* If no profiles have been have been configured then this
* does nothing.
*/
for (i = 0; i < srtp_pref; i++) {
sprof = sk_SRTP_PROTECTION_PROFILE_value(srvr, i);
if (sprof->id == id) {
s->srtp_profile = sprof;
srtp_pref = i;
break;
}
}
}
/*
* Now extract the MKI value as a sanity check, but discard it for now
*/
if (!PACKET_get_1(pkt, &mki_len)) {
SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT,
SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
*al = SSL_AD_DECODE_ERROR;
return 1;
}
if (!PACKET_forward(pkt, mki_len)
|| PACKET_remaining(pkt)) {
SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT,
SSL_R_BAD_SRTP_MKI_VALUE);
*al = SSL_AD_DECODE_ERROR;
return 1;
}
return 0;
}
int ssl_add_serverhello_use_srtp_ext(SSL *s, unsigned char *p, int *len,
int maxlen)
{
if (p) {
if (maxlen < 5) {
SSLerr(SSL_F_SSL_ADD_SERVERHELLO_USE_SRTP_EXT,
SSL_R_SRTP_PROTECTION_PROFILE_LIST_TOO_LONG);
return 1;
}
if (s->srtp_profile == 0) {
SSLerr(SSL_F_SSL_ADD_SERVERHELLO_USE_SRTP_EXT,
SSL_R_USE_SRTP_NOT_NEGOTIATED);
return 1;
}
s2n(2, p);
s2n(s->srtp_profile->id, p);
*p++ = 0;
}
*len = 5;
return 0;
}
int ssl_parse_serverhello_use_srtp_ext(SSL *s, PACKET *pkt, int *al)
{
unsigned int id, ct, mki;
int i;
STACK_OF(SRTP_PROTECTION_PROFILE) *clnt;
SRTP_PROTECTION_PROFILE *prof;
if (!PACKET_get_net_2(pkt, &ct)
|| ct != 2 || !PACKET_get_net_2(pkt, &id)
|| !PACKET_get_1(pkt, &mki)
|| PACKET_remaining(pkt) != 0) {
SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_USE_SRTP_EXT,
SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
*al = SSL_AD_DECODE_ERROR;
return 1
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