Migrate to libsrtp2

This commit is contained in:
Marvin W 2021-03-29 13:20:12 +02:00
parent c7d1ee4dc5
commit 5e58f29883
No known key found for this signature in database
GPG Key ID: 072E9235DB996F2A
12 changed files with 314 additions and 1102 deletions

12
cmake/FindSrtp2.cmake Normal file
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@ -0,0 +1,12 @@
include(PkgConfigWithFallback)
find_pkg_config_with_fallback(Srtp2
PKG_CONFIG_NAME libsrtp2
LIB_NAMES srtp2
INCLUDE_NAMES srtp2/srtp.h
INCLUDE_DIR_SUFFIXES srtp2 srtp2/include
)
include(FindPackageHandleStandardArgs)
find_package_handle_standard_args(Srtp2
REQUIRED_VARS Srtp2_LIBRARY
VERSION_VAR Srtp2_VERSION)

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@ -3,6 +3,7 @@ find_packages(CRYPTO_VALA_PACKAGES REQUIRED
GLib
GObject
GIO
Srtp2
)
vala_precompile(CRYPTO_VALA_C
@ -11,44 +12,23 @@ SOURCES
"src/cipher_converter.vala"
"src/error.vala"
"src/random.vala"
"src/srtp.vapi"
"src/srtp.vala"
CUSTOM_VAPIS
"${CMAKE_CURRENT_SOURCE_DIR}/vapi/gcrypt.vapi"
"${CMAKE_CURRENT_SOURCE_DIR}/vapi/libsrtp2.vapi"
PACKAGES
${CRYPTO_VALA_PACKAGES}
OPTIONS
--vapidir=${CMAKE_CURRENT_SOURCE_DIR}/vapi
GENERATE_VAPI
crypto-vala
GENERATE_HEADER
crypto-vala
)
add_custom_command(OUTPUT "${CMAKE_BINARY_DIR}/exports/srtp.h"
COMMAND
cp "${CMAKE_CURRENT_SOURCE_DIR}/src/srtp.h" "${CMAKE_BINARY_DIR}/exports/srtp.h"
DEPENDS
"${CMAKE_CURRENT_SOURCE_DIR}/src/srtp.h"
COMMENT
Copy header file srtp.h
)
add_custom_command(OUTPUT ${CMAKE_BINARY_DIR}/exports/crypto.vapi
COMMAND
cat "${CMAKE_BINARY_DIR}/exports/crypto-vala.vapi" "${CMAKE_CURRENT_SOURCE_DIR}/src/srtp.vapi" > "${CMAKE_BINARY_DIR}/exports/crypto.vapi"
DEPENDS
${CMAKE_BINARY_DIR}/exports/crypto-vala.vapi
${CMAKE_CURRENT_SOURCE_DIR}/src/srtp.vapi
)
add_custom_target(crypto-vapi
DEPENDS
${CMAKE_BINARY_DIR}/exports/crypto.vapi
${CMAKE_BINARY_DIR}/exports/srtp.h
)
set(CFLAGS ${VALA_CFLAGS} -I${CMAKE_CURRENT_SOURCE_DIR}/src)
set(CFLAGS ${VALA_CFLAGS})
add_definitions(${CFLAGS})
add_library(crypto-vala STATIC ${CRYPTO_VALA_C} src/srtp.c)
add_dependencies(crypto-vala crypto-vapi)
add_library(crypto-vala STATIC ${CRYPTO_VALA_C})
target_link_libraries(crypto-vala ${CRYPTO_VALA_PACKAGES} gcrypt)
set_property(TARGET crypto-vala PROPERTY POSITION_INDEPENDENT_CODE ON)

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@ -2,7 +2,9 @@ namespace Crypto {
public errordomain Error {
ILLEGAL_ARGUMENTS,
GCRYPT
GCRYPT,
AUTHENTICATION_FAILED,
UNKNOWN
}
internal void may_throw_gcrypt_error(GCrypt.Error e) throws Error {

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@ -1,836 +0,0 @@
/*
* Secure RTP with libgcrypt
* Copyright (C) 2007 Rémi Denis-Courmont
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
/* TODO:
* Useless stuff (because nothing depends on it):
* - non-nul key derivation rate
* - MKI payload
*/
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <stdint.h>
#include <stddef.h>
#include "srtp.h"
#include <stdbool.h>
#include <stdlib.h>
#include <assert.h>
#include <errno.h>
#include <gcrypt.h>
#ifdef _WIN32
# include <winsock2.h>
#else
# include <netinet/in.h>
#endif
#define debug( ... ) (void)0
typedef struct srtp_proto_t
{
gcry_cipher_hd_t cipher;
gcry_md_hd_t mac;
uint64_t window;
uint32_t salt[4];
} srtp_proto_t;
struct srtp_session_t
{
srtp_proto_t rtp;
srtp_proto_t rtcp;
unsigned flags;
unsigned kdr;
uint32_t rtcp_index;
uint32_t rtp_roc;
uint16_t rtp_seq;
uint16_t rtp_rcc;
uint8_t tag_len;
};
enum
{
SRTP_CRYPT,
SRTP_AUTH,
SRTP_SALT,
SRTCP_CRYPT,
SRTCP_AUTH,
SRTCP_SALT
};
static inline unsigned rcc_mode (const srtp_session_t *s)
{
return (s->flags >> 4) & 3;
}
static void proto_destroy (srtp_proto_t *p)
{
gcry_md_close (p->mac);
gcry_cipher_close (p->cipher);
}
/**
* Releases all resources associated with a Secure RTP session.
*/
void srtp_destroy (srtp_session_t *s)
{
assert (s != NULL);
proto_destroy (&s->rtcp);
proto_destroy (&s->rtp);
free (s);
}
static int proto_create (srtp_proto_t *p, int gcipher, int gmd)
{
if (gcry_cipher_open (&p->cipher, gcipher, GCRY_CIPHER_MODE_CTR, 0) == 0)
{
if (gcry_md_open (&p->mac, gmd, GCRY_MD_FLAG_HMAC) == 0)
return 0;
gcry_cipher_close (p->cipher);
}
return -1;
}
/**
* Allocates a Secure RTP one-way session.
* The same session cannot be used both ways because this would confuse
* internal cryptographic counters; it is however of course feasible to open
* multiple simultaneous sessions with the same master key.
*
* @param encr encryption algorithm number
* @param auth authentication algortihm number
* @param tag_len authentication tag byte length (NOT including RCC)
* @param flags OR'ed optional flags.
*
* @return NULL in case of error
*/
srtp_session_t *
srtp_create (int encr, int auth, unsigned tag_len, int prf, unsigned flags)
{
if ((flags & ~SRTP_FLAGS_MASK))
return NULL;
int cipher, md;
switch (encr)
{
case SRTP_ENCR_NULL:
cipher = GCRY_CIPHER_NONE;
break;
case SRTP_ENCR_AES_CM:
cipher = GCRY_CIPHER_AES;
break;
default:
return NULL;
}
switch (auth)
{
case SRTP_AUTH_NULL:
md = GCRY_MD_NONE;
break;
case SRTP_AUTH_HMAC_SHA1:
md = GCRY_MD_SHA1;
break;
default:
return NULL;
}
if (tag_len > gcry_md_get_algo_dlen (md))
return NULL;
if (prf != SRTP_PRF_AES_CM)
return NULL;
srtp_session_t *s = malloc (sizeof (*s));
if (s == NULL)
return NULL;
memset (s, 0, sizeof (*s));
s->flags = flags;
s->tag_len = tag_len;
s->rtp_rcc = 1; /* Default RCC rate */
if (rcc_mode (s))
{
if (tag_len < 4)
goto error;
}
if (proto_create (&s->rtp, cipher, md) == 0)
{
if (proto_create (&s->rtcp, cipher, md) == 0)
return s;
proto_destroy (&s->rtp);
}
error:
free (s);
return NULL;
}
/**
* Counter Mode encryption/decryption (ctr length = 16 bytes)
* with non-padded (truncated) text
*/
static int
do_ctr_crypt (gcry_cipher_hd_t hd, const void *ctr, uint8_t *data, size_t len)
{
const size_t ctrlen = 16;
div_t d = div (len, ctrlen);
if (gcry_cipher_setctr (hd, ctr, ctrlen)
|| gcry_cipher_encrypt (hd, data, d.quot * ctrlen, NULL, 0))
return -1;
if (d.rem)
{
/* Truncated last block */
uint8_t dummy[ctrlen];
data += d.quot * ctrlen;
memcpy (dummy, data, d.rem);
memset (dummy + d.rem, 0, ctrlen - d.rem);
if (gcry_cipher_encrypt (hd, dummy, ctrlen, data, ctrlen))
return -1;
memcpy (data, dummy, d.rem);
}
return 0;
}
/**
* AES-CM key derivation (saltlen = 14 bytes)
*/
static int
do_derive (gcry_cipher_hd_t prf, const void *salt,
const uint8_t *r, size_t rlen, uint8_t label,
void *out, size_t outlen)
{
uint8_t iv[16];
memcpy (iv, salt, 14);
iv[14] = iv[15] = 0;
assert (rlen < 14);
iv[13 - rlen] ^= label;
for (size_t i = 0; i < rlen; i++)
iv[sizeof (iv) - rlen + i] ^= r[i];
memset (out, 0, outlen);
return do_ctr_crypt (prf, iv, out, outlen);
}
/**
* Sets (or resets) the master key and master salt for a SRTP session.
* This must be done at least once before using srtp_send(), srtp_recv(),
* srtcp_send() or srtcp_recv(). Also, rekeying is required every
* 2^48 RTP packets or 2^31 RTCP packets (whichever comes first),
* otherwise the protocol security might be broken.
*
* @return 0 on success, in case of error:
* EINVAL invalid or unsupported key/salt sizes combination
*/
int
srtp_setkey (srtp_session_t *s, const void *key, size_t keylen,
const void *salt, size_t saltlen)
{
/* SRTP/SRTCP cipher/salt/MAC keys derivation */
gcry_cipher_hd_t prf;
uint8_t r[6], keybuf[20];
if (saltlen != 14)
return EINVAL;
if (gcry_cipher_open (&prf, GCRY_CIPHER_AES, GCRY_CIPHER_MODE_CTR, 0)
|| gcry_cipher_setkey (prf, key, keylen))
return EINVAL;
/* SRTP key derivation */
#if 0
if (s->kdr != 0)
{
uint64_t index = (((uint64_t)s->rtp_roc) << 16) | s->rtp_seq;
index /= s->kdr;
for (int i = sizeof (r) - 1; i >= 0; i--)
{
r[i] = index & 0xff;
index = index >> 8;
}
}
else
#endif
memset (r, 0, sizeof (r));
if (do_derive (prf, salt, r, 6, SRTP_CRYPT, keybuf, 16)
|| gcry_cipher_setkey (s->rtp.cipher, keybuf, 16)
|| do_derive (prf, salt, r, 6, SRTP_AUTH, keybuf, 20)
|| gcry_md_setkey (s->rtp.mac, keybuf, 20)
|| do_derive (prf, salt, r, 6, SRTP_SALT, s->rtp.salt, 14))
return -1;
/* SRTCP key derivation */
memcpy (r, &(uint32_t){ htonl (s->rtcp_index) }, 4);
if (do_derive (prf, salt, r, 4, SRTCP_CRYPT, keybuf, 16)
|| gcry_cipher_setkey (s->rtcp.cipher, keybuf, 16)
|| do_derive (prf, salt, r, 4, SRTCP_AUTH, keybuf, 20)
|| gcry_md_setkey (s->rtcp.mac, keybuf, 20)
|| do_derive (prf, salt, r, 4, SRTCP_SALT, s->rtcp.salt, 14))
return -1;
(void)gcry_cipher_close (prf);
return 0;
}
static int hexdigit (char c)
{
if ((c >= '0') && (c <= '9'))
return c - '0';
if ((c >= 'A') && (c <= 'F'))
return c - 'A' + 0xA;
if ((c >= 'a') && (c <= 'f'))
return c - 'a' + 0xa;
return -1;
}
static ssize_t hexstring (const char *in, uint8_t *out, size_t outlen)
{
size_t inlen = strlen (in);
if ((inlen > (2 * outlen)) || (inlen & 1))
return -1;
for (size_t i = 0; i < inlen; i += 2)
{
int a = hexdigit (in[i]), b = hexdigit (in[i + 1]);
if ((a == -1) || (b == -1))
return -1;
out[i / 2] = (a << 4) | b;
}
return inlen / 2;
}
/**
* Sets (or resets) the master key and master salt for a SRTP session
* from hexadecimal strings. See also srtp_setkey().
*
* @return 0 on success, in case of error:
* EINVAL invalid or unsupported key/salt sizes combination
*/
int
srtp_setkeystring (srtp_session_t *s, const char *key, const char *salt)
{
uint8_t bkey[16]; /* TODO/NOTE: hard-coded for AES */
uint8_t bsalt[14]; /* TODO/NOTE: hard-coded for the PRF-AES-CM */
ssize_t bkeylen = hexstring (key, bkey, sizeof (bkey));
ssize_t bsaltlen = hexstring (salt, bsalt, sizeof (bsalt));
if ((bkeylen == -1) || (bsaltlen == -1))
return EINVAL;
return srtp_setkey (s, bkey, bkeylen, bsalt, bsaltlen) ? EINVAL : 0;
}
/**
* Sets Roll-over-Counter Carry (RCC) rate for the SRTP session. If not
* specified (through this function), the default rate of ONE is assumed
* (i.e. every RTP packets will carry the RoC). RCC rate is ignored if none
* of the RCC mode has been selected.
*
* The RCC mode is selected through one of these flags for srtp_create():
* SRTP_RCC_MODE1: integrity protection only for RoC carrying packets
* SRTP_RCC_MODE2: integrity protection for all packets
* SRTP_RCC_MODE3: no integrity protection
*
* RCC mode 3 is insecure. Compared to plain RTP, it provides confidentiality
* (through encryption) but is much more prone to DoS. It can only be used if
* anti-spoofing protection is provided by lower network layers (e.g. IPsec,
* or trusted routers and proper source address filtering).
*
* If RCC rate is 1, RCC mode 1 and 2 are functionally identical.
*
* @param rate RoC Carry rate (MUST NOT be zero)
*/
void srtp_setrcc_rate (srtp_session_t *s, uint16_t rate)
{
assert (rate != 0);
s->rtp_rcc = rate;
}
/** AES-CM for RTP (salt = 14 bytes + 2 nul bytes) */
static int
rtp_crypt (gcry_cipher_hd_t hd, uint32_t ssrc, uint32_t roc, uint16_t seq,
const uint32_t *salt, uint8_t *data, size_t len)
{
/* Determines cryptographic counter (IV) */
uint32_t counter[4];
counter[0] = salt[0];
counter[1] = salt[1] ^ ssrc;
counter[2] = salt[2] ^ htonl (roc);
counter[3] = salt[3] ^ htonl (seq << 16);
/* Encryption */
return do_ctr_crypt (hd, counter, data, len);
}
/** Determines SRTP Roll-Over-Counter (in host-byte order) */
static uint32_t
srtp_compute_roc (const srtp_session_t *s, uint16_t seq)
{
uint32_t roc = s->rtp_roc;
if (((seq - s->rtp_seq) & 0xffff) < 0x8000)
{
/* Sequence is ahead, good */
if (seq < s->rtp_seq)
roc++; /* Sequence number wrap */
}
else
{
/* Sequence is late, bad */
if (seq > s->rtp_seq)
roc--; /* Wrap back */
}
return roc;
}
/** Returns RTP sequence (in host-byte order) */
static inline uint16_t rtp_seq (const uint8_t *buf)
{
return (buf[2] << 8) | buf[3];
}
/** Message Authentication and Integrity for RTP */
static const uint8_t *
rtp_digest (gcry_md_hd_t md, const uint8_t *data, size_t len,
uint32_t roc)
{
gcry_md_reset (md);
gcry_md_write (md, data, len);
gcry_md_write (md, &(uint32_t){ htonl (roc) }, 4);
return gcry_md_read (md, 0);
}
/**
* Encrypts/decrypts a RTP packet and updates SRTP context
* (CTR block cypher mode of operation has identical encryption and
* decryption function).
*
* @param buf RTP packet to be en-/decrypted
* @param len RTP packet length
*
* @return 0 on success, in case of error:
* EINVAL malformatted RTP packet
* EACCES replayed packet or out-of-window or sync lost
*/
static int srtp_crypt (srtp_session_t *s, uint8_t *buf, size_t len)
{
assert (s != NULL);
assert (len >= 12u);
if ((buf[0] >> 6) != 2)
return EINVAL;
/* Computes encryption offset */
uint16_t offset = 12;
offset += (buf[0] & 0xf) * 4; // skips CSRC
if (buf[0] & 0x10)
{
uint16_t extlen;
offset += 4;
if (len < offset)
return EINVAL;
memcpy (&extlen, buf + offset - 2, 2);
offset += htons (extlen); // skips RTP extension header
}
if (len < offset)
return EINVAL;
/* Determines RTP 48-bits counter and SSRC */
uint16_t seq = rtp_seq (buf);
uint32_t roc = srtp_compute_roc (s, seq), ssrc;
memcpy (&ssrc, buf + 8, 4);
/* Updates ROC and sequence (it's safe now) */
int16_t diff = seq - s->rtp_seq;
if (diff > 0)
{
/* Sequence in the future, good */
s->rtp.window = s->rtp.window << diff;
s->rtp.window |= UINT64_C(1);
s->rtp_seq = seq, s->rtp_roc = roc;
}
else
{
/* Sequence in the past/present, bad */
diff = -diff;
if ((diff >= 64) || ((s->rtp.window >> diff) & 1))
return EACCES; /* Replay attack */
s->rtp.window |= UINT64_C(1) << diff;
}
/* Encrypt/Decrypt */
if (s->flags & SRTP_UNENCRYPTED)
return 0;
if (rtp_crypt (s->rtp.cipher, ssrc, roc, seq, s->rtp.salt,
buf + offset, len - offset))
return EINVAL;
return 0;
}
/**
* Turns a RTP packet into a SRTP packet: encrypt it, then computes
* the authentication tag and appends it.
* Note that you can encrypt packet in disorder.
*
* @param buf RTP packet to be encrypted/digested
* @param lenp pointer to the RTP packet length on entry,
* set to the SRTP length on exit (undefined on non-ENOSPC error)
* @param bufsize size (bytes) of the packet buffer
*
* @return 0 on success, in case of error:
* EINVAL malformatted RTP packet or internal error
* ENOSPC bufsize is too small to add authentication tag
* (<lenp> will hold the required byte size)
* EACCES packet would trigger a replay error on receiver
*/
int
srtp_send (srtp_session_t *s, uint8_t *buf, size_t *lenp, size_t bufsize)
{
size_t len = *lenp;
size_t tag_len;
size_t roc_len = 0;
/* Compute required buffer size */
if (len < 12u)
return EINVAL;
if (!(s->flags & SRTP_UNAUTHENTICATED))
{
tag_len = s->tag_len;
if (rcc_mode (s))
{
assert (tag_len >= 4);
assert (s->rtp_rcc != 0);
if ((rtp_seq (buf) % s->rtp_rcc) == 0)
{
roc_len = 4;
if (rcc_mode (s) == 3)
tag_len = 0; /* RCC mode 3 -> no auth*/
else
tag_len -= 4; /* RCC mode 1 or 2 -> auth*/
}
else
{
if (rcc_mode (s) & 1)
tag_len = 0; /* RCC mode 1 or 3 -> no auth */
}
}
*lenp = len + roc_len + tag_len;
}
else
tag_len = 0;
if (bufsize < *lenp)
return ENOSPC;
/* Encrypt payload */
int val = srtp_crypt (s, buf, len);
if (val)
return val;
/* Authenticate payload */
if (!(s->flags & SRTP_UNAUTHENTICATED))
{
uint32_t roc = srtp_compute_roc (s, rtp_seq (buf));
const uint8_t *tag = rtp_digest (s->rtp.mac, buf, len, roc);
if (roc_len)
{
memcpy (buf + len, &(uint32_t){ htonl (s->rtp_roc) }, 4);
len += 4;
}
memcpy (buf + len, tag, tag_len);
#if 0
printf ("Sent : 0x");
for (unsigned i = 0; i < tag_len; i++)
printf ("%02x", tag[i]);
puts ("");
#endif
}
return 0;
}
/**
* Turns a SRTP packet into a RTP packet: authenticates the packet,
* then decrypts it.
*
* @param buf RTP packet to be digested/decrypted
* @param lenp pointer to the SRTP packet length on entry,
* set to the RTP length on exit (undefined in case of error)
*
* @return 0 on success, in case of error:
* EINVAL malformatted SRTP packet
* EACCES authentication failed (spoofed packet or out-of-sync)
*/
int
srtp_recv (srtp_session_t *s, uint8_t *buf, size_t *lenp)
{
size_t len = *lenp;
if (len < 12u)
return EINVAL;
if (!(s->flags & SRTP_UNAUTHENTICATED))
{
size_t tag_len = s->tag_len, roc_len = 0;
if (rcc_mode (s))
{
if ((rtp_seq (buf) % s->rtp_rcc) == 0)
{
roc_len = 4;
if (rcc_mode (s) == 3)
tag_len = 0;
else
tag_len -= 4;
}
else
{
if (rcc_mode (s) & 1)
tag_len = 0; // RCC mode 1 or 3: no auth
}
}
if (len < (12u + roc_len + tag_len))
return EINVAL;
len -= roc_len + tag_len;
uint32_t roc = srtp_compute_roc (s, rtp_seq (buf)), rcc;
if (roc_len)
{
assert (roc_len == 4);
memcpy (&rcc, buf + len, 4);
rcc = ntohl (rcc);
}
else
rcc = roc;
const uint8_t *tag = rtp_digest (s->rtp.mac, buf, len, rcc);
#if 0
printf ("Computed: 0x");
for (unsigned i = 0; i < tag_len; i++)
printf ("%02x", tag[i]);
printf ("\nReceived: 0x");
for (unsigned i = 0; i < tag_len; i++)
printf ("%02x", buf[len + roc_len + i]);
puts ("");
#endif
if (memcmp (buf + len + roc_len, tag, tag_len))
return EACCES;
if (roc_len)
{
/* Authenticated packet carried a Roll-Over-Counter */
s->rtp_roc += rcc - roc;
assert (srtp_compute_roc (s, rtp_seq (buf)) == rcc);
}
*lenp = len;
}
return srtp_crypt (s, buf, len);
}
/** AES-CM for RTCP (salt = 14 bytes + 2 nul bytes) */
static int
rtcp_crypt (gcry_cipher_hd_t hd, uint32_t ssrc, uint32_t index,
const uint32_t *salt, uint8_t *data, size_t len)
{
return rtp_crypt (hd, ssrc, index >> 16, index & 0xffff, salt, data, len);
}
/** Message Authentication and Integrity for RTCP */
static const uint8_t *
rtcp_digest (gcry_md_hd_t md, const void *data, size_t len)
{
gcry_md_reset (md);
gcry_md_write (md, data, len);
return gcry_md_read (md, 0);
}
/**
* Encrypts/decrypts a RTCP packet and updates SRTCP context
* (CTR block cypher mode of operation has identical encryption and
* decryption function).
*
* @param buf RTCP packet to be en-/decrypted
* @param len RTCP packet length
*
* @return 0 on success, in case of error:
* EINVAL malformatted RTCP packet
*/
static int srtcp_crypt (srtp_session_t *s, uint8_t *buf, size_t len)
{
assert (s != NULL);
/* 8-bytes unencrypted header, and 4-bytes unencrypted footer */
if ((len < 12) || ((buf[0] >> 6) != 2))
return EINVAL;
uint32_t index;
memcpy (&index, buf + len, 4);
index = ntohl (index);
if (((index >> 31) != 0) != ((s->flags & SRTCP_UNENCRYPTED) == 0))
return EINVAL; // E-bit mismatch
index &= ~(1 << 31); // clear E-bit for counter
/* Updates SRTCP index (safe here) */
int32_t diff = index - s->rtcp_index;
if (diff > 0)
{
/* Packet in the future, good */
s->rtcp.window = s->rtcp.window << diff;
s->rtcp.window |= UINT64_C(1);
s->rtcp_index = index;
}
else
{
/* Packet in the past/present, bad */
diff = -diff;
if ((diff >= 64) || ((s->rtcp.window >> diff) & 1))
return EACCES; // replay attack!
s->rtp.window |= UINT64_C(1) << diff;
}
/* Crypts SRTCP */
if (s->flags & SRTCP_UNENCRYPTED)
return 0;
uint32_t ssrc;
memcpy (&ssrc, buf + 4, 4);
if (rtcp_crypt (s->rtcp.cipher, ssrc, index, s->rtp.salt,
buf + 8, len - 8))
return EINVAL;
return 0;
}
/**
* Turns a RTCP packet into a SRTCP packet: encrypt it, then computes
* the authentication tag and appends it.
*
* @param buf RTCP packet to be encrypted/digested
* @param lenp pointer to the RTCP packet length on entry,
* set to the SRTCP length on exit (undefined in case of error)
* @param bufsize size (bytes) of the packet buffer
*
* @return 0 on success, in case of error:
* EINVAL malformatted RTCP packet or internal error
* ENOSPC bufsize is too small (to add index and authentication tag)
*/
int
srtcp_send (srtp_session_t *s, uint8_t *buf, size_t *lenp, size_t bufsize)
{
size_t len = *lenp;
if (bufsize < (len + 4 + s->tag_len))
return ENOSPC;
uint32_t index = ++s->rtcp_index;
if (index >> 31)
s->rtcp_index = index = 0; /* 31-bit wrap */
if ((s->flags & SRTCP_UNENCRYPTED) == 0)
index |= 0x80000000; /* Set Encrypted bit */
memcpy (buf + len, &(uint32_t){ htonl (index) }, 4);
int val = srtcp_crypt (s, buf, len);
if (val)
return val;
len += 4; /* Digests SRTCP index too */
const uint8_t *tag = rtcp_digest (s->rtcp.mac, buf, len);
memcpy (buf + len, tag, s->tag_len);
*lenp = len + s->tag_len;
return 0;
}
/**
* Turns a SRTCP packet into a RTCP packet: authenticates the packet,
* then decrypts it.
*
* @param buf RTCP packet to be digested/decrypted
* @param lenp pointer to the SRTCP packet length on entry,
* set to the RTCP length on exit (undefined in case of error)
*
* @return 0 on success, in case of error:
* EINVAL malformatted SRTCP packet
* EACCES authentication failed (spoofed packet or out-of-sync)
*/
int
srtcp_recv (srtp_session_t *s, uint8_t *buf, size_t *lenp)
{
size_t len = *lenp;
if (len < (4u + s->tag_len))
return EINVAL;
len -= s->tag_len;
const uint8_t *tag = rtcp_digest (s->rtcp.mac, buf, len);
if (memcmp (buf + len, tag, s->tag_len))
return EACCES;
len -= 4; /* Remove SRTCP index before decryption */
*lenp = len;
return srtcp_crypt (s, buf, len);
}

View File

@ -1,82 +0,0 @@
/*
* Secure RTP with libgcrypt
* Copyright (C) 2007 Rémi Denis-Courmont
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2.1
* of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
****************************************************************************/
#ifndef LIBVLC_SRTP_H
# define LIBVLC_SRTP_H 1
#include <stdint.h>
typedef struct srtp_session_t srtp_session_t;
enum
{
SRTP_UNENCRYPTED=0x1, //< do not encrypt SRTP packets
SRTCP_UNENCRYPTED=0x2, //< do not encrypt SRTCP packets
SRTP_UNAUTHENTICATED=0x4, //< authenticate only SRTCP packets
SRTP_RCC_MODE1=0x10, //< use Roll-over-Counter Carry mode 1
SRTP_RCC_MODE2=0x20, //< use Roll-over-Counter Carry mode 2
SRTP_RCC_MODE3=0x30, //< use Roll-over-Counter Carry mode 3 (insecure)
SRTP_FLAGS_MASK=0x37 //< mask for valid flags
};
/** SRTP encryption algorithms (ciphers); same values as MIKEY */
enum
{
SRTP_ENCR_NULL=0, //< no encryption
SRTP_ENCR_AES_CM=1, //< AES counter mode
SRTP_ENCR_AES_F8=2, //< AES F8 mode (not implemented)
};
/** SRTP authenticaton algorithms; same values as MIKEY */
enum
{
SRTP_AUTH_NULL=0, //< no authentication code
SRTP_AUTH_HMAC_SHA1=1, //< HMAC-SHA1
};
/** SRTP pseudo random function; same values as MIKEY */
enum
{
SRTP_PRF_AES_CM=0, //< AES counter mode
};
# ifdef __cplusplus
extern "C" {
# endif
srtp_session_t *srtp_create (int encr, int auth, unsigned tag_len, int prf,
unsigned flags);
void srtp_destroy (srtp_session_t *s);
int srtp_setkey (srtp_session_t *s, const void *key, size_t keylen,
const void *salt, size_t saltlen);
int srtp_setkeystring (srtp_session_t *s, const char *key, const char *salt);
void srtp_setrcc_rate (srtp_session_t *s, uint16_t rate);
int srtp_send (srtp_session_t *s, uint8_t *buf, size_t *lenp, size_t maxsize);
int srtp_recv (srtp_session_t *s, uint8_t *buf, size_t *lenp);
int srtcp_send (srtp_session_t *s, uint8_t *buf, size_t *lenp, size_t maxsiz);
int srtcp_recv (srtp_session_t *s, uint8_t *buf, size_t *lenp);
# ifdef __cplusplus
}
# endif
#endif

View File

@ -0,0 +1,122 @@
using Srtp;
public class Crypto.Srtp {
public const string AES_CM_128_HMAC_SHA1_80 = "AES_CM_128_HMAC_SHA1_80";
public const string AES_CM_128_HMAC_SHA1_32 = "AES_CM_128_HMAC_SHA1_32";
public const string F8_128_HMAC_SHA1_80 = "F8_128_HMAC_SHA1_80";
public class Session {
public bool has_encrypt { get; private set; }
public bool has_decrypt { get; private set; }
private Context encrypt_context;
private Context decrypt_context;
static construct {
init();
install_log_handler(log);
}
private static void log(LogLevel level, string msg) {
print(@"SRTP[$level]: $msg\n");
}
public Session() {
Context.create(out encrypt_context, null);
Context.create(out decrypt_context, null);
}
public uint8[] encrypt_rtp(uint8[] data) throws Error {
uint8[] buf = new uint8[data.length + MAX_TRAILER_LEN];
Memory.copy(buf, data, data.length);
int buf_use = data.length;
ErrorStatus res = encrypt_context.protect(buf, ref buf_use);
if (res != ErrorStatus.ok) {
throw new Error.UNKNOWN(@"SRTP encrypt failed: $res");
}
uint8[] ret = new uint8[buf_use];
GLib.Memory.copy(ret, buf, buf_use);
return ret;
}
public uint8[] decrypt_rtp(uint8[] data) throws Error {
uint8[] buf = new uint8[data.length];
Memory.copy(buf, data, data.length);
int buf_use = data.length;
ErrorStatus res = decrypt_context.unprotect(buf, ref buf_use);
switch (res) {
case ErrorStatus.auth_fail:
throw new Error.AUTHENTICATION_FAILED("SRTP packet failed the message authentication check");
case ErrorStatus.ok:
break;
default:
throw new Error.UNKNOWN(@"SRTP decrypt failed: $res");
}
uint8[] ret = new uint8[buf_use];
GLib.Memory.copy(ret, buf, buf_use);
return ret;
}
public uint8[] encrypt_rtcp(uint8[] data) throws Error {
uint8[] buf = new uint8[data.length + MAX_TRAILER_LEN + 4];
Memory.copy(buf, data, data.length);
int buf_use = data.length;
ErrorStatus res = encrypt_context.protect_rtcp(buf, ref buf_use);
if (res != ErrorStatus.ok) {
throw new Error.UNKNOWN(@"SRTCP encrypt failed: $res");
}
uint8[] ret = new uint8[buf_use];
GLib.Memory.copy(ret, buf, buf_use);
return ret;
}
public uint8[] decrypt_rtcp(uint8[] data) throws Error {
uint8[] buf = new uint8[data.length];
Memory.copy(buf, data, data.length);
int buf_use = data.length;
ErrorStatus res = decrypt_context.unprotect_rtcp(buf, ref buf_use);
switch (res) {
case ErrorStatus.auth_fail:
throw new Error.AUTHENTICATION_FAILED("SRTCP packet failed the message authentication check");
case ErrorStatus.ok:
break;
default:
throw new Error.UNKNOWN(@"SRTP decrypt failed: $res");
}
uint8[] ret = new uint8[buf_use];
GLib.Memory.copy(ret, buf, buf_use);
return ret;
}
private Policy create_policy(string profile) {
Policy policy = Policy();
switch (profile) {
case AES_CM_128_HMAC_SHA1_80:
policy.rtp.set_aes_cm_128_hmac_sha1_80();
policy.rtcp.set_aes_cm_128_hmac_sha1_80();
break;
}
return policy;
}
public void set_encryption_key(string profile, uint8[] key, uint8[] salt) {
Policy policy = create_policy(profile);
policy.ssrc.type = SsrcType.any_outbound;
policy.key = new uint8[key.length + salt.length];
Memory.copy(policy.key, key, key.length);
Memory.copy(((uint8*)policy.key) + key.length, salt, salt.length);
encrypt_context.add_stream(ref policy);
has_encrypt = true;
}
public void set_decryption_key(string profile, uint8[] key, uint8[] salt) {
Policy policy = create_policy(profile);
policy.ssrc.type = SsrcType.any_inbound;
policy.key = new uint8[key.length + salt.length];
Memory.copy(policy.key, key, key.length);
Memory.copy(((uint8*)policy.key) + key.length, salt, salt.length);
decrypt_context.add_stream(ref policy);
has_decrypt = true;
}
}
}

View File

@ -1,107 +0,0 @@
[CCode (cheader_filename="srtp.h")]
namespace Crypto.Srtp {
[Compact]
[CCode (cname = "srtp_session_t", free_function = "srtp_destroy")]
public class Session {
[CCode (cname = "srtp_create")]
public Session(Encryption encr, Authentication auth, uint tag_len, Prf prf, Flags flags);
[CCode (cname = "srtp_setkey")]
public int setkey(uint8[] key, uint8[] salt);
[CCode (cname = "srtp_setkeystring")]
public int setkeystring(string key, string salt);
[CCode (cname = "srtp_setrcc_rate")]
public void setrcc_rate(uint16 rate);
[CCode (cname = "srtp_send")]
private int rtp_send([CCode (array_length = false)] uint8[] buf, ref size_t len, size_t maxsize);
[CCode (cname = "srtcp_send")]
private int rtcp_send([CCode (array_length = false)] uint8[] buf, ref size_t len, size_t maxsize);
[CCode (cname = "srtp_recv")]
private int rtp_recv([CCode (array_length = false)] uint8[] buf, ref size_t len);
[CCode (cname = "srtcp_recv")]
private int rtcp_recv([CCode (array_length = false)] uint8[] buf, ref size_t len);
public uint8[] encrypt_rtp(uint8[] input, uint tag_len = 10) throws GLib.Error {
uint8[] buf = new uint8[input.length + tag_len];
GLib.Memory.copy(buf, input, input.length);
size_t buf_use = input.length;
int res = rtp_send(buf, ref buf_use, buf.length);
if (res != 0) {
throw new GLib.Error(-1, res, "RTP encrypt failed");
}
uint8[] ret = new uint8[buf_use];
GLib.Memory.copy(ret, buf, buf_use);
return ret;
}
public uint8[] encrypt_rtcp(uint8[] input, uint tag_len = 10) throws GLib.Error {
uint8[] buf = new uint8[input.length + tag_len + 4];
GLib.Memory.copy(buf, input, input.length);
size_t buf_use = input.length;
int res = rtcp_send(buf, ref buf_use, buf.length);
if (res != 0) {
throw new GLib.Error(-1, res, "RTCP encrypt failed");
}
uint8[] ret = new uint8[buf_use];
GLib.Memory.copy(ret, buf, buf_use);
return ret;
}
public uint8[] decrypt_rtp(uint8[] input) throws GLib.Error {
uint8[] buf = new uint8[input.length];
GLib.Memory.copy(buf, input, input.length);
size_t buf_use = input.length;
int res = rtp_recv(buf, ref buf_use);
if (res != 0) {
throw new GLib.Error(-1, res, "RTP decrypt failed");
}
uint8[] ret = new uint8[buf_use];
GLib.Memory.copy(ret, buf, buf_use);
return ret;
}
public uint8[] decrypt_rtcp(uint8[] input) throws GLib.Error {
uint8[] buf = new uint8[input.length];
GLib.Memory.copy(buf, input, input.length);
size_t buf_use = input.length;
int res = rtcp_recv(buf, ref buf_use);
if (res != 0) {
throw new GLib.Error(-1, res, "RTCP decrypt failed");
}
uint8[] ret = new uint8[buf_use];
GLib.Memory.copy(ret, buf, buf_use);
return ret;
}
}
[Flags]
[CCode (cname = "unsigned", cprefix = "", has_type_id = false)]
public enum Flags {
SRTP_UNENCRYPTED,
SRTCP_UNENCRYPTED,
SRTP_UNAUTHENTICATED,
SRTP_RCC_MODE1,
SRTP_RCC_MODE2,
SRTP_RCC_MODE3
}
[CCode (cname = "int", cprefix = "SRTP_ENCR_", has_type_id = false)]
public enum Encryption {
NULL,
AES_CM,
AES_F8
}
[CCode (cname = "int", cprefix = "SRTP_AUTH_", has_type_id = false)]
public enum Authentication {
NULL,
HMAC_SHA1
}
[CCode (cname = "int", cprefix = "SRTP_PRF_", has_type_id = false)]
public enum Prf {
AES_CM
}
}

View File

@ -0,0 +1,115 @@
[CCode (cheader_filename = "srtp2/srtp.h")]
namespace Srtp {
public const uint MAX_TRAILER_LEN;
public static ErrorStatus init();
public static ErrorStatus shutdown();
[Compact]
[CCode (cname = "srtp_ctx_t", cprefix = "srtp_", free_function = "srtp_dealloc")]
public class Context {
public static ErrorStatus create(out Context session, Policy? policy);
public ErrorStatus protect([CCode (type = "void*", array_length = false)] uint8[] rtp, ref int len);
public ErrorStatus unprotect([CCode (type = "void*", array_length = false)] uint8[] rtp, ref int len);
public ErrorStatus protect_rtcp([CCode (type = "void*", array_length = false)] uint8[] rtcp, ref int len);
public ErrorStatus unprotect_rtcp([CCode (type = "void*", array_length = false)] uint8[] rtcp, ref int len);
public ErrorStatus add_stream(ref Policy policy);
public ErrorStatus update_stream(ref Policy policy);
public ErrorStatus remove_stream(uint ssrc);
public ErrorStatus update(ref Policy policy);
}
[CCode (cname = "srtp_ssrc_t")]
public struct Ssrc {
public SsrcType type;
public uint value;
}
[CCode (cname = "srtp_ssrc_type_t", cprefix = "ssrc_")]
public enum SsrcType {
undefined, specific, any_inbound, any_outbound
}
[CCode (cname = "srtp_policy_t", destroy_function = "")]
public struct Policy {
public Ssrc ssrc;
public CryptoPolicy rtp;
public CryptoPolicy rtcp;
[CCode (array_length = false)]
public uint8[] key;
public ulong num_master_keys;
public ulong window_size;
public int allow_repeat_tx;
[CCode (array_length_cname = "enc_xtn_hdr_count")]
public int[] enc_xtn_hdr;
}
[CCode (cname = "srtp_crypto_policy_t")]
public struct CryptoPolicy {
public CipherType cipher_type;
public int cipher_key_len;
public AuthType auth_type;
public int auth_key_len;
public int auth_tag_len;
public SecurityServices sec_serv;
public void set_aes_cm_128_hmac_sha1_80();
public void set_aes_cm_128_hmac_sha1_32();
public void set_aes_cm_128_null_auth();
public void set_aes_cm_192_hmac_sha1_32();
public void set_aes_cm_192_hmac_sha1_80();
public void set_aes_cm_192_null_auth();
public void set_aes_cm_256_hmac_sha1_32();
public void set_aes_cm_256_hmac_sha1_80();
public void set_aes_cm_256_null_auth();
public void set_aes_gcm_128_16_auth();
public void set_aes_gcm_128_8_auth();
public void set_aes_gcm_128_8_only_auth();
public void set_aes_gcm_256_16_auth();
public void set_aes_gcm_256_8_auth();
public void set_aes_gcm_256_8_only_auth();
public void set_null_cipher_hmac_null();
public void set_null_cipher_hmac_sha1_80();
public void set_rtp_default();
public void set_rtcp_default();
public void set_from_profile_for_rtp(Profile profile);
public void set_from_profile_for_rtcp(Profile profile);
}
[CCode (cname = "srtp_profile_t", cprefix = "srtp_profile_")]
public enum Profile {
reserved, aes128_cm_sha1_80, aes128_cm_sha1_32, null_sha1_80, null_sha1_32, aead_aes_128_gcm, aead_aes_256_gcm
}
[CCode (cname = "srtp_cipher_type_id_t")]
public struct CipherType : uint32 {}
[CCode (cname = "srtp_auth_type_id_t")]
public struct AuthType : uint32 {}
[CCode (cname = "srtp_sec_serv_t", cprefix = "sec_serv_")]
public enum SecurityServices {
none, conf, auth, conf_and_auth;
}
[CCode (cname = "srtp_err_status_t", cprefix = "srtp_err_status_", has_type_id = false)]
public enum ErrorStatus {
ok, fail, bad_param, alloc_fail, dealloc_fail, init_fail, terminus, auth_fail, cipher_fail, replay_fail, algo_fail, no_such_op, no_ctx, cant_check, key_expired, socket_err, signal_err, nonce_bad, encode_err, semaphore_err, pfkey_err, bad_mki, pkt_idx_old, pkt_idx_adv
}
[CCode (cname = "srtp_log_level_t", cprefix = "srtp_log_level_", has_type_id = false)]
public enum LogLevel {
error, warning, info, debug
}
[CCode (cname = "srtp_log_handler_func_t")]
public delegate void LogHandler(LogLevel level, string msg);
public static ErrorStatus install_log_handler(LogHandler func);
}

View File

@ -20,7 +20,7 @@ CUSTOM_VAPIS
${CMAKE_BINARY_DIR}/exports/xmpp-vala.vapi
${CMAKE_BINARY_DIR}/exports/dino.vapi
${CMAKE_BINARY_DIR}/exports/qlite.vapi
${CMAKE_BINARY_DIR}/exports/crypto.vapi
${CMAKE_BINARY_DIR}/exports/crypto-vala.vapi
PACKAGES
${ICE_PACKAGES}
OPTIONS

View File

@ -12,8 +12,7 @@ public class DtlsSrtp {
private uint pull_timeout = uint.MAX;
private string peer_fingerprint;
private Crypto.Srtp.Session encrypt_session;
private Crypto.Srtp.Session decrypt_session;
private Crypto.Srtp.Session srtp_session = new Crypto.Srtp.Session();
public static DtlsSrtp setup() throws GLib.Error {
var obj = new DtlsSrtp();
@ -30,9 +29,19 @@ public class DtlsSrtp {
}
public uint8[] process_incoming_data(uint component_id, uint8[] data) {
if (decrypt_session != null) {
if (component_id == 1) return decrypt_session.decrypt_rtp(data);
if (component_id == 2) return decrypt_session.decrypt_rtcp(data);
if (srtp_session.has_decrypt) {
try {
if (component_id == 1) {
if (data.length >= 2 && data[1] >= 192 && data[1] < 224) {
return srtp_session.decrypt_rtcp(data);
}
return srtp_session.decrypt_rtp(data);
}
if (component_id == 2) return srtp_session.decrypt_rtcp(data);
} catch (Error e) {
warning("%s (%d)", e.message, e.code);
return null;
}
} else if (component_id == 1) {
on_data_rec(data);
}
@ -40,9 +49,19 @@ public class DtlsSrtp {
}
public uint8[] process_outgoing_data(uint component_id, uint8[] data) {
if (encrypt_session != null) {
if (component_id == 1) return encrypt_session.encrypt_rtp(data);
if (component_id == 2) return encrypt_session.encrypt_rtcp(data);
if (srtp_session.has_encrypt) {
try {
if (component_id == 1) {
if (data.length >= 2 && data[1] >= 192 && data[1] < 224) {
return srtp_session.encrypt_rtcp(data);
}
return srtp_session.encrypt_rtp(data);
}
if (component_id == 2) return srtp_session.encrypt_rtcp(data);
} catch (Error e) {
warning("%s (%d)", e.message, e.code);
return null;
}
}
return null;
}
@ -123,19 +142,13 @@ public class DtlsSrtp {
warning("SRTP client/server key/salt null");
}
Crypto.Srtp.Session encrypt_session = new Crypto.Srtp.Session(Crypto.Srtp.Encryption.AES_CM, Crypto.Srtp.Authentication.HMAC_SHA1, 10, Crypto.Srtp.Prf.AES_CM, 0);
Crypto.Srtp.Session decrypt_session = new Crypto.Srtp.Session(Crypto.Srtp.Encryption.AES_CM, Crypto.Srtp.Authentication.HMAC_SHA1, 10, Crypto.Srtp.Prf.AES_CM, 0);
if (server) {
encrypt_session.setkey(server_key.extract(), server_salt.extract());
decrypt_session.setkey(client_key.extract(), client_salt.extract());
srtp_session.set_encryption_key(Crypto.Srtp.AES_CM_128_HMAC_SHA1_80, server_key.extract(), server_salt.extract());
srtp_session.set_decryption_key(Crypto.Srtp.AES_CM_128_HMAC_SHA1_80, client_key.extract(), client_salt.extract());
} else {
encrypt_session.setkey(client_key.extract(), client_salt.extract());
decrypt_session.setkey(server_key.extract(), server_salt.extract());
srtp_session.set_encryption_key(Crypto.Srtp.AES_CM_128_HMAC_SHA1_80, client_key.extract(), client_salt.extract());
srtp_session.set_decryption_key(Crypto.Srtp.AES_CM_128_HMAC_SHA1_80, server_key.extract(), server_salt.extract());
}
this.encrypt_session = (owned)encrypt_session;
this.decrypt_session = (owned)decrypt_session;
}
private static ssize_t pull_function(void* transport_ptr, uint8[] buffer) {

View File

@ -19,7 +19,7 @@ SOURCES
src/video_widget.vala
src/register_plugin.vala
CUSTOM_VAPIS
${CMAKE_BINARY_DIR}/exports/crypto.vapi
${CMAKE_BINARY_DIR}/exports/crypto-vala.vapi
${CMAKE_BINARY_DIR}/exports/xmpp-vala.vapi
${CMAKE_BINARY_DIR}/exports/dino.vapi
${CMAKE_BINARY_DIR}/exports/qlite.vapi

View File

@ -53,8 +53,7 @@ public class Dino.Plugins.Rtp.Stream : Xmpp.Xep.JingleRtp.Stream {
private Gst.Pad send_rtp_sink_pad;
private Gst.Pad send_rtp_src_pad;
private Crypto.Srtp.Session? local_crypto_session;
private Crypto.Srtp.Session? remote_crypto_session;
private Crypto.Srtp.Session? crypto_session = new Crypto.Srtp.Session();
public Stream(Plugin plugin, Xmpp.Xep.Jingle.Content content) {
base(content);
@ -148,15 +147,8 @@ public class Dino.Plugins.Rtp.Stream : Xmpp.Xep.JingleRtp.Stream {
}
private void prepare_local_crypto() {
if (local_crypto != null && local_crypto_session == null) {
local_crypto_session = new Crypto.Srtp.Session(
local_crypto.crypto_suite == Xep.JingleRtp.Crypto.F8_128_HMAC_SHA1_80 ? Crypto.Srtp.Encryption.AES_F8 : Crypto.Srtp.Encryption.AES_CM,
Crypto.Srtp.Authentication.HMAC_SHA1,
local_crypto.crypto_suite == Xep.JingleRtp.Crypto.AES_CM_128_HMAC_SHA1_32 ? 4 : 10,
Crypto.Srtp.Prf.AES_CM,
0
);
local_crypto_session.setkey(local_crypto.key, local_crypto.salt);
if (local_crypto != null && !crypto_session.has_encrypt) {
crypto_session.set_encryption_key(local_crypto.crypto_suite, local_crypto.key, local_crypto.salt);
debug("Setting up encryption with key params %s", local_crypto.key_params);
}
}
@ -172,15 +164,19 @@ public class Dino.Plugins.Rtp.Stream : Xmpp.Xep.JingleRtp.Stream {
buffer.extract_dup(0, buffer.get_size(), out data);
prepare_local_crypto();
if (sink == send_rtp) {
if (local_crypto_session != null) {
data = local_crypto_session.encrypt_rtp(data, local_crypto.crypto_suite == Xep.JingleRtp.Crypto.AES_CM_128_HMAC_SHA1_32 ? 4 : 10);
if (crypto_session.has_encrypt) {
data = crypto_session.encrypt_rtp(data);
}
on_send_rtp_data(new Bytes.take(data));
} else if (sink == send_rtcp) {
if (local_crypto_session != null) {
data = local_crypto_session.encrypt_rtcp(data, local_crypto.crypto_suite == Xep.JingleRtp.Crypto.AES_CM_128_HMAC_SHA1_32 ? 4 : 10);
if (crypto_session.has_encrypt) {
data = crypto_session.encrypt_rtcp(data);
}
if (rtcp_mux) {
on_send_rtp_data(new Bytes.take(data));
} else {
on_send_rtcp_data(new Bytes.take(data));
}
on_send_rtcp_data(new Bytes.take(data));
} else {
warning("unknown sample");
}
@ -283,25 +279,22 @@ public class Dino.Plugins.Rtp.Stream : Xmpp.Xep.JingleRtp.Stream {
}
private void prepare_remote_crypto() {
if (remote_crypto != null && remote_crypto_session == null) {
remote_crypto_session = new Crypto.Srtp.Session(
remote_crypto.crypto_suite == Xep.JingleRtp.Crypto.F8_128_HMAC_SHA1_80 ? Crypto.Srtp.Encryption.AES_F8 : Crypto.Srtp.Encryption.AES_CM,
Crypto.Srtp.Authentication.HMAC_SHA1,
remote_crypto.crypto_suite == Xep.JingleRtp.Crypto.AES_CM_128_HMAC_SHA1_32 ? 4 : 10,
Crypto.Srtp.Prf.AES_CM,
0
);
remote_crypto_session.setkey(remote_crypto.key, remote_crypto.salt);
if (remote_crypto != null && crypto_session.has_decrypt) {
crypto_session.set_decryption_key(remote_crypto.crypto_suite, remote_crypto.key, remote_crypto.salt);
debug("Setting up decryption with key params %s", remote_crypto.key_params);
}
}
public override void on_recv_rtp_data(Bytes bytes) {
if (rtcp_mux && bytes.length >= 2 && bytes.get(1) >= 192 && bytes.get(1) < 224) {
on_recv_rtcp_data(bytes);
return;
}
prepare_remote_crypto();
uint8[] data = bytes.get_data();
if (remote_crypto_session != null) {
if (crypto_session.has_decrypt) {
try {
data = remote_crypto_session.decrypt_rtp(data);
data = crypto_session.decrypt_rtp(data);
} catch (Error e) {
warning("%s (%d)", e.message, e.code);
}
@ -314,9 +307,9 @@ public class Dino.Plugins.Rtp.Stream : Xmpp.Xep.JingleRtp.Stream {
public override void on_recv_rtcp_data(Bytes bytes) {
prepare_remote_crypto();
uint8[] data = bytes.get_data();
if (remote_crypto_session != null) {
if (crypto_session.has_decrypt) {
try {
data = remote_crypto_session.decrypt_rtcp(data);
data = crypto_session.decrypt_rtcp(data);
} catch (Error e) {
warning("%s (%d)", e.message, e.code);
}