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/*
* This file is part of the Nice GLib ICE library.
*
* (C) 2007 Nokia Corporation. All rights reserved.
* Contact: Rémi Denis-Courmont
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is the Nice GLib ICE library.
*
* The Initial Developers of the Original Code are Collabora Ltd and Nokia
* Corporation. All Rights Reserved.
*
* Contributors:
* Rémi Denis-Courmont, Nokia
*
* Alternatively, the contents of this file may be used under the terms of the
* the GNU Lesser General Public License Version 2.1 (the "LGPL"), in which
* case the provisions of LGPL are applicable instead of those above. If you
* wish to allow use of your version of this file only under the terms of the
* LGPL and not to allow others to use your version of this file under the
* MPL, indicate your decision by deleting the provisions above and replace
* them with the notice and other provisions required by the LGPL. If you do
* not delete the provisions above, a recipient may use your version of this
* file under either the MPL or the LGPL.
*/
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <openssl/evp.h>
#include <openssl/hmac.h>
#include <openssl/rand.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <pthread.h>
#include "stun-msg.h"
#include "stunhmac.h"
#include <string.h>
#include <assert.h>
void stun_sha1 (const uint8_t *msg, size_t len, uint8_t *sha,
const void *restrict key, size_t keylen)
{
HMAC_CTX ctx;
uint16_t fakelen = htons (len - 20u);
assert (len >= 44u);
HMAC_CTX_init (&ctx);
HMAC_Init_ex (&ctx, key, keylen, EVP_sha1 (), NULL);
HMAC_Update (&ctx, msg, 2);
HMAC_Update (&ctx, (const uint8_t *)&fakelen, 2);
/* first 4 bytes done, last 24 bytes not summed */
HMAC_Update (&ctx, msg + 4, len - 28u);
HMAC_Final (&ctx, sha, NULL);
HMAC_CTX_cleanup (&ctx);
}
void stun_hash_creds (const char *realm, const char *login, const char *pw,
unsigned char md5[16])
{
EVP_MD_CTX ctx;
assert (realm && login && pw && md5);
EVP_MD_CTX_init (&ctx);
EVP_DigestInit_ex (&ctx, EVP_md5 (), NULL);
EVP_DigestUpdate (&ctx, realm, strlen (realm));
EVP_DigestUpdate (&ctx, ":", 1);
EVP_DigestUpdate (&ctx, login, strlen (login));
EVP_DigestUpdate (&ctx, ":", 1);
EVP_DigestUpdate (&ctx, pw, strlen (pw));
EVP_DigestFinal (&ctx, md5, NULL);
}
void stun_make_transid (stun_transid_t id)
{
/*
* transid = (HMAC_SHA1 (secret, counter) >> 64)
* This consumes sizeof (secret) bytes of entropy every 2^64 messages.
*/
static struct
{
pthread_mutex_t lock;
uint64_t counter;
uint8_t secret[16];
} store = { PTHREAD_MUTEX_INITIALIZER, 0, "" };
union
{
uint64_t value;
uint8_t bytes[1];
} counter;
uint8_t key[16], sha[20];
pthread_mutex_lock (&store.lock);
counter.value = store.counter++;
if (counter.value == 0)
RAND_pseudo_bytes (store.secret, sizeof (store.secret));
memcpy (key, store.secret, sizeof (key));
pthread_mutex_unlock (&store.lock);
/* Computes hash out of contentious area */
HMAC (EVP_sha1 (), key, sizeof (key), counter.bytes, sizeof (counter),
sha, NULL);
memcpy (id, sha, 12);
}
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