ff_srtp_free(s);
// RFC 4568
- if (!strcmp(suite, "AES_CM_128_HMAC_SHA1_80")) {
- s->hmac_size = 10;
+ 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->hmac_size = 4;
+ 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);
{
uint8_t iv[16] = { 0 }, hmac[20];
int len = *lenptr;
- int ext, seq_largest;
- uint32_t ssrc, roc;
+ int av_uninit(seq_largest);
+ uint32_t ssrc, av_uninit(roc);
uint64_t index;
- int rtcp;
+ int rtcp, hmac_size;
// TODO: Missing replay protection
- if (len < s->hmac_size)
+ 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 - s->hmac_size);
+ av_hmac_update(s->hmac, buf, len - hmac_size);
if (!rtcp) {
int seq = AV_RB16(buf + 2);
}
av_hmac_final(s->hmac, hmac, sizeof(hmac));
- if (memcmp(hmac, buf + len - s->hmac_size, s->hmac_size)) {
+ if (memcmp(hmac, buf + len - hmac_size, hmac_size)) {
av_log(NULL, AV_LOG_WARNING, "HMAC mismatch\n");
return AVERROR_INVALIDDATA;
}
- len -= s->hmac_size;
+ len -= hmac_size;
*lenptr = len;
if (len < 12)
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;
uint8_t iv[16] = { 0 }, hmac[20];
uint64_t index;
uint32_t ssrc;
- int rtcp;
+ int rtcp, hmac_size, padding;
uint8_t *buf;
- if (len + 14 > outlen)
- return 0;
- if (len < 12)
+ 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;
- rtcp = RTP_PT_IS_RTCP(buf[1]);
-
if (rtcp) {
ssrc = AV_RB32(buf + 4);
index = s->rtcp_index++;
buf += 8;
len -= 8;
} else {
- int ext;
+ 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->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;
}
av_hmac_final(s->hmac, hmac, sizeof(hmac));
- memcpy(buf + len, hmac, s->hmac_size);
- len += s->hmac_size;
+ 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 */
projects / ffmpeg / blobdiff