diff options
| author | Tim Redfern <tim@eclectronics.org> | 2013-09-05 17:55:35 +0100 |
|---|---|---|
| committer | Tim Redfern <tim@eclectronics.org> | 2013-09-05 17:55:35 +0100 |
| commit | 741fb4b9e135cfb161a749db88713229038577bb (patch) | |
| tree | 08bc9925659cbcac45162bacf31dc6336d4f60b4 /ffmpeg1/libavformat/srtp.c | |
| parent | a2e1bf3495b7bfefdaedb8fc737e969ab06df079 (diff) | |
making act segmenter
Diffstat (limited to 'ffmpeg1/libavformat/srtp.c')
| -rw-r--r-- | ffmpeg1/libavformat/srtp.c | 471 |
1 files changed, 0 insertions, 471 deletions
diff --git a/ffmpeg1/libavformat/srtp.c b/ffmpeg1/libavformat/srtp.c deleted file mode 100644 index 65309d0..0000000 --- a/ffmpeg1/libavformat/srtp.c +++ /dev/null @@ -1,471 +0,0 @@ -/* - * SRTP encryption/decryption - * Copyright (c) 2012 Martin Storsjo - * - * This file is part of FFmpeg. - * - * FFmpeg 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. - * - * FFmpeg 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 FFmpeg; if not, write to the Free Software - * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA - */ - -#include "libavutil/base64.h" -#include "libavutil/aes.h" -#include "libavutil/hmac.h" -#include "libavutil/intreadwrite.h" -#include "libavutil/log.h" -#include "rtp.h" -#include "srtp.h" - -void ff_srtp_free(struct SRTPContext *s) -{ - if (!s) - return; - av_freep(&s->aes); - if (s->hmac) - av_hmac_free(s->hmac); - s->hmac = NULL; -} - -static void encrypt_counter(struct AVAES *aes, uint8_t *iv, uint8_t *outbuf, - int outlen) -{ - int i, j, outpos; - for (i = 0, outpos = 0; outpos < outlen; i++) { - uint8_t keystream[16]; - AV_WB16(&iv[14], i); - av_aes_crypt(aes, keystream, iv, 1, NULL, 0); - for (j = 0; j < 16 && outpos < outlen; j++, outpos++) - outbuf[outpos] ^= keystream[j]; - } -} - -static void derive_key(struct AVAES *aes, const uint8_t *salt, int label, - uint8_t *out, int outlen) -{ - uint8_t input[16] = { 0 }; - memcpy(input, salt, 14); - // Key derivation rate assumed to be zero - input[14 - 7] ^= label; - memset(out, 0, outlen); - encrypt_counter(aes, input, out, outlen); -} - -int ff_srtp_set_crypto(struct SRTPContext *s, const char *suite, - const char *params) -{ - uint8_t buf[30]; - - ff_srtp_free(s); - - // RFC 4568 - if (!strcmp(suite, "AES_CM_128_HMAC_SHA1_80") || - !strcmp(suite, "SRTP_AES128_CM_HMAC_SHA1_80")) { - s->rtp_hmac_size = s->rtcp_hmac_size = 10; - } else if (!strcmp(suite, "AES_CM_128_HMAC_SHA1_32")) { - s->rtp_hmac_size = s->rtcp_hmac_size = 4; - } else if (!strcmp(suite, "SRTP_AES128_CM_HMAC_SHA1_32")) { - // RFC 5764 section 4.1.2 - s->rtp_hmac_size = 4; - s->rtcp_hmac_size = 10; - } else { - av_log(NULL, AV_LOG_WARNING, "SRTP Crypto suite %s not supported\n", - suite); - return AVERROR(EINVAL); - } - if (av_base64_decode(buf, params, sizeof(buf)) != sizeof(buf)) { - av_log(NULL, AV_LOG_WARNING, "Incorrect amount of SRTP params\n"); - return AVERROR(EINVAL); - } - // MKI and lifetime not handled yet - s->aes = av_aes_alloc(); - s->hmac = av_hmac_alloc(AV_HMAC_SHA1); - if (!s->aes || !s->hmac) - return AVERROR(ENOMEM); - memcpy(s->master_key, buf, 16); - memcpy(s->master_salt, buf + 16, 14); - - // RFC 3711 - av_aes_init(s->aes, s->master_key, 128, 0); - - derive_key(s->aes, s->master_salt, 0x00, s->rtp_key, sizeof(s->rtp_key)); - derive_key(s->aes, s->master_salt, 0x02, s->rtp_salt, sizeof(s->rtp_salt)); - derive_key(s->aes, s->master_salt, 0x01, s->rtp_auth, sizeof(s->rtp_auth)); - - derive_key(s->aes, s->master_salt, 0x03, s->rtcp_key, sizeof(s->rtcp_key)); - derive_key(s->aes, s->master_salt, 0x05, s->rtcp_salt, sizeof(s->rtcp_salt)); - derive_key(s->aes, s->master_salt, 0x04, s->rtcp_auth, sizeof(s->rtcp_auth)); - return 0; -} - -static void create_iv(uint8_t *iv, const uint8_t *salt, uint64_t index, - uint32_t ssrc) -{ - uint8_t indexbuf[8]; - int i; - memset(iv, 0, 16); - AV_WB32(&iv[4], ssrc); - AV_WB64(indexbuf, index); - for (i = 0; i < 8; i++) // index << 16 - iv[6 + i] ^= indexbuf[i]; - for (i = 0; i < 14; i++) - iv[i] ^= salt[i]; -} - -int ff_srtp_decrypt(struct SRTPContext *s, uint8_t *buf, int *lenptr) -{ - uint8_t iv[16] = { 0 }, hmac[20]; - int len = *lenptr; - int av_uninit(seq_largest); - uint32_t ssrc, av_uninit(roc); - uint64_t index; - int rtcp, hmac_size; - - // TODO: Missing replay protection - - if (len < 2) - return AVERROR_INVALIDDATA; - - rtcp = RTP_PT_IS_RTCP(buf[1]); - hmac_size = rtcp ? s->rtcp_hmac_size : s->rtp_hmac_size; - - if (len < hmac_size) - return AVERROR_INVALIDDATA; - - // Authentication HMAC - av_hmac_init(s->hmac, rtcp ? s->rtcp_auth : s->rtp_auth, sizeof(s->rtp_auth)); - // If MKI is used, this should exclude the MKI as well - av_hmac_update(s->hmac, buf, len - hmac_size); - - if (!rtcp) { - int seq = AV_RB16(buf + 2); - uint32_t v; - uint8_t rocbuf[4]; - - // RFC 3711 section 3.3.1, appendix A - seq_largest = s->seq_initialized ? s->seq_largest : seq; - v = roc = s->roc; - if (seq_largest < 32768) { - if (seq - seq_largest > 32768) - v = roc - 1; - } else { - if (seq_largest - 32768 > seq) - v = roc + 1; - } - if (v == roc) { - seq_largest = FFMAX(seq_largest, seq); - } else if (v == roc + 1) { - seq_largest = seq; - roc = v; - } - index = seq + (((uint64_t)v) << 16); - - AV_WB32(rocbuf, roc); - av_hmac_update(s->hmac, rocbuf, 4); - } - - av_hmac_final(s->hmac, hmac, sizeof(hmac)); - if (memcmp(hmac, buf + len - hmac_size, hmac_size)) { - av_log(NULL, AV_LOG_WARNING, "HMAC mismatch\n"); - return AVERROR_INVALIDDATA; - } - - len -= hmac_size; - *lenptr = len; - - if (len < 12) - return AVERROR_INVALIDDATA; - - if (rtcp) { - uint32_t srtcp_index = AV_RB32(buf + len - 4); - len -= 4; - *lenptr = len; - - ssrc = AV_RB32(buf + 4); - index = srtcp_index & 0x7fffffff; - - buf += 8; - len -= 8; - if (!(srtcp_index & 0x80000000)) - return 0; - } else { - int ext, csrc; - s->seq_initialized = 1; - s->seq_largest = seq_largest; - s->roc = roc; - - csrc = buf[0] & 0x0f; - ext = buf[0] & 0x10; - ssrc = AV_RB32(buf + 8); - - buf += 12; - len -= 12; - - buf += 4 * csrc; - len -= 4 * csrc; - if (len < 0) - return AVERROR_INVALIDDATA; - - if (ext) { - if (len < 4) - return AVERROR_INVALIDDATA; - ext = (AV_RB16(buf + 2) + 1) * 4; - if (len < ext) - return AVERROR_INVALIDDATA; - len -= ext; - buf += ext; - } - } - - create_iv(iv, rtcp ? s->rtcp_salt : s->rtp_salt, index, ssrc); - av_aes_init(s->aes, rtcp ? s->rtcp_key : s->rtp_key, 128, 0); - encrypt_counter(s->aes, iv, buf, len); - - return 0; -} - -int ff_srtp_encrypt(struct SRTPContext *s, const uint8_t *in, int len, - uint8_t *out, int outlen) -{ - uint8_t iv[16] = { 0 }, hmac[20]; - uint64_t index; - uint32_t ssrc; - int rtcp, hmac_size, padding; - uint8_t *buf; - - if (len < 8) - return AVERROR_INVALIDDATA; - - rtcp = RTP_PT_IS_RTCP(in[1]); - hmac_size = rtcp ? s->rtcp_hmac_size : s->rtp_hmac_size; - padding = hmac_size; - if (rtcp) - padding += 4; // For the RTCP index - - if (len + padding > outlen) - return 0; - - memcpy(out, in, len); - buf = out; - - if (rtcp) { - ssrc = AV_RB32(buf + 4); - index = s->rtcp_index++; - - buf += 8; - len -= 8; - } else { - int ext, csrc; - int seq = AV_RB16(buf + 2); - - if (len < 12) - return AVERROR_INVALIDDATA; - - ssrc = AV_RB32(buf + 8); - - if (seq < s->seq_largest) - s->roc++; - s->seq_largest = seq; - index = seq + (((uint64_t)s->roc) << 16); - - csrc = buf[0] & 0x0f; - ext = buf[0] & 0x10; - - buf += 12; - len -= 12; - - buf += 4 * csrc; - len -= 4 * csrc; - if (len < 0) - return AVERROR_INVALIDDATA; - - if (ext) { - if (len < 4) - return AVERROR_INVALIDDATA; - ext = (AV_RB16(buf + 2) + 1) * 4; - if (len < ext) - return AVERROR_INVALIDDATA; - len -= ext; - buf += ext; - } - } - - create_iv(iv, rtcp ? s->rtcp_salt : s->rtp_salt, index, ssrc); - av_aes_init(s->aes, rtcp ? s->rtcp_key : s->rtp_key, 128, 0); - encrypt_counter(s->aes, iv, buf, len); - - if (rtcp) { - AV_WB32(buf + len, 0x80000000 | index); - len += 4; - } - - av_hmac_init(s->hmac, rtcp ? s->rtcp_auth : s->rtp_auth, sizeof(s->rtp_auth)); - av_hmac_update(s->hmac, out, buf + len - out); - if (!rtcp) { - uint8_t rocbuf[4]; - AV_WB32(rocbuf, s->roc); - av_hmac_update(s->hmac, rocbuf, 4); - } - av_hmac_final(s->hmac, hmac, sizeof(hmac)); - - memcpy(buf + len, hmac, hmac_size); - len += hmac_size; - return buf + len - out; -} - -#ifdef TEST -#include <stdio.h> - -static const char *aes128_80_key = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmn"; - -static const uint8_t rtp_aes128_80[] = { - // RTP header - 0x80, 0xe0, 0x12, 0x34, 0x12, 0x34, 0x56, 0x78, 0x12, 0x34, 0x56, 0x78, - // encrypted payload - 0x62, 0x69, 0x76, 0xca, 0xc5, - // HMAC - 0xa1, 0xac, 0x1b, 0xb4, 0xa0, 0x1c, 0xd5, 0x49, 0x28, 0x99, -}; - -static const uint8_t rtcp_aes128_80[] = { - // RTCP header - 0x81, 0xc9, 0x00, 0x07, 0x12, 0x34, 0x56, 0x78, - // encrypted payload - 0x8a, 0xac, 0xdc, 0xa5, 0x4c, 0xf6, 0x78, 0xa6, 0x62, 0x8f, 0x24, 0xda, - 0x6c, 0x09, 0x3f, 0xa9, 0x28, 0x7a, 0xb5, 0x7f, 0x1f, 0x0f, 0xc9, 0x35, - // RTCP index - 0x80, 0x00, 0x00, 0x03, - // HMAC - 0xe9, 0x3b, 0xc0, 0x5c, 0x0c, 0x06, 0x9f, 0xab, 0xc0, 0xde, -}; - -static const char *aes128_32_key = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmn"; - -static const uint8_t rtp_aes128_32[] = { - // RTP header - 0x80, 0xe0, 0x12, 0x34, 0x12, 0x34, 0x56, 0x78, 0x12, 0x34, 0x56, 0x78, - // encrypted payload - 0x62, 0x69, 0x76, 0xca, 0xc5, - // HMAC - 0xa1, 0xac, 0x1b, 0xb4, -}; - -static const uint8_t rtcp_aes128_32[] = { - // RTCP header - 0x81, 0xc9, 0x00, 0x07, 0x12, 0x34, 0x56, 0x78, - // encrypted payload - 0x35, 0xe9, 0xb5, 0xff, 0x0d, 0xd1, 0xde, 0x70, 0x74, 0x10, 0xaa, 0x1b, - 0xb2, 0x8d, 0xf0, 0x20, 0x02, 0x99, 0x6b, 0x1b, 0x0b, 0xd0, 0x47, 0x34, - // RTCP index - 0x80, 0x00, 0x00, 0x04, - // HMAC - 0x5b, 0xd2, 0xa9, 0x9d, -}; - -static const char *aes128_80_32_key = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmn"; - -static const uint8_t rtp_aes128_80_32[] = { - // RTP header - 0x80, 0xe0, 0x12, 0x34, 0x12, 0x34, 0x56, 0x78, 0x12, 0x34, 0x56, 0x78, - // encrypted payload - 0x62, 0x69, 0x76, 0xca, 0xc5, - // HMAC - 0xa1, 0xac, 0x1b, 0xb4, -}; - -static const uint8_t rtcp_aes128_80_32[] = { - // RTCP header - 0x81, 0xc9, 0x00, 0x07, 0x12, 0x34, 0x56, 0x78, - // encrypted payload - 0xd6, 0xae, 0xc1, 0x58, 0x63, 0x70, 0xc9, 0x88, 0x66, 0x26, 0x1c, 0x53, - 0xff, 0x5d, 0x5d, 0x2b, 0x0f, 0x8c, 0x72, 0x3e, 0xc9, 0x1d, 0x43, 0xf9, - // RTCP index - 0x80, 0x00, 0x00, 0x05, - // HMAC - 0x09, 0x16, 0xb4, 0x27, 0x9a, 0xe9, 0x92, 0x26, 0x4e, 0x10, -}; - -static void print_data(const uint8_t *buf, int len) -{ - int i; - for (i = 0; i < len; i++) - printf("%02x", buf[i]); - printf("\n"); -} - -static int test_decrypt(struct SRTPContext *srtp, const uint8_t *in, int len, - uint8_t *out) -{ - memcpy(out, in, len); - if (!ff_srtp_decrypt(srtp, out, &len)) { - print_data(out, len); - return len; - } else - return -1; -} - -static void test_encrypt(const uint8_t *data, int in_len, const char *suite, - const char *key) -{ - struct SRTPContext enc = { 0 }, dec = { 0 }; - int len; - char buf[1500]; - ff_srtp_set_crypto(&enc, suite, key); - ff_srtp_set_crypto(&dec, suite, key); - len = ff_srtp_encrypt(&enc, data, in_len, buf, sizeof(buf)); - if (!ff_srtp_decrypt(&dec, buf, &len)) { - if (len == in_len && !memcmp(buf, data, len)) - printf("Decrypted content matches input\n"); - else - printf("Decrypted content doesn't match input\n"); - } else { - printf("Decryption failed\n"); - } - ff_srtp_free(&enc); - ff_srtp_free(&dec); -} - -int main(void) -{ - static const char *aes128_80_suite = "AES_CM_128_HMAC_SHA1_80"; - static const char *aes128_32_suite = "AES_CM_128_HMAC_SHA1_32"; - static const char *aes128_80_32_suite = "SRTP_AES128_CM_HMAC_SHA1_32"; - static const char *test_key = "abcdefghijklmnopqrstuvwxyz1234567890ABCD"; - uint8_t buf[1500]; - struct SRTPContext srtp = { 0 }; - int len; - ff_srtp_set_crypto(&srtp, aes128_80_suite, aes128_80_key); - len = test_decrypt(&srtp, rtp_aes128_80, sizeof(rtp_aes128_80), buf); - test_encrypt(buf, len, aes128_80_suite, test_key); - test_encrypt(buf, len, aes128_32_suite, test_key); - test_encrypt(buf, len, aes128_80_32_suite, test_key); - test_decrypt(&srtp, rtcp_aes128_80, sizeof(rtcp_aes128_80), buf); - test_encrypt(buf, len, aes128_80_suite, test_key); - test_encrypt(buf, len, aes128_32_suite, test_key); - test_encrypt(buf, len, aes128_80_32_suite, test_key); - ff_srtp_free(&srtp); - - memset(&srtp, 0, sizeof(srtp)); // Clear the context - ff_srtp_set_crypto(&srtp, aes128_32_suite, aes128_32_key); - test_decrypt(&srtp, rtp_aes128_32, sizeof(rtp_aes128_32), buf); - test_decrypt(&srtp, rtcp_aes128_32, sizeof(rtcp_aes128_32), buf); - ff_srtp_free(&srtp); - - memset(&srtp, 0, sizeof(srtp)); // Clear the context - ff_srtp_set_crypto(&srtp, aes128_80_32_suite, aes128_80_32_key); - test_decrypt(&srtp, rtp_aes128_80_32, sizeof(rtp_aes128_80_32), buf); - test_decrypt(&srtp, rtcp_aes128_80_32, sizeof(rtcp_aes128_80_32), buf); - ff_srtp_free(&srtp); - return 0; -} -#endif /* TEST */ |
