Changeset 7bdd4ba5b1c58233b656c75e4abd9017f7ef02ee

Timestamp:

03/11/07 19:53:53 (1 year ago)

Author:

Rémi Denis-Courmont <rem@videolan.org>

git-committer:

Rémi Denis-Courmont <rem@videolan.org> 1173639233 +0000

git-parent:

[a65a62289c22ad0c988d833eb25e3a616b524aba]

git-author:

Rémi Denis-Courmont <rem@videolan.org> 1173639233 +0000

Message:

Untested support for RFC4771:
Integrity Transform Carrying Roll-Over Counter for SRTP

Once debugged, it should provide a simple way to synchronize live
(multicast...) secure streams.

Files:

• libs/srtp/srtp.c (modified) (9 diffs)

libs/srtp/srtp.c

@@ -18 +18 @@
- */
-
+/* TODO:
+ * Useless stuff (because nothing depends on it):
+ * - non-nul key derivation rate
+ * - MKI payload
+ */
+
-#ifdef HAVE_CONFIG_H
-# include <config.h>
@@ -34 +40 @@
-#include <gcrypt.h>
-
+#ifdef WIN32
+# include <winsock2.h>
+#else
+# include <netinet/in.h>
+# include <pthread.h>
+GCRY_THREAD_OPTION_PTHREAD_IMPL;
+#endif
+
-#define debug( ... ) (void)0
-
-/* TODO:
- * Useful stuff:
- * - ROC profile thingy (multicast really needs this)
- *
- * Useless stuff (because nothing depends on it):
- * - non-nul key derivation rate
- * - MKI payload
- */
-
-typedef struct srtp_proto_t
@@ -77 +82 @@
-
-
-
-
-
-
-
-
-
+
+
+
+
-
-static bool libgcrypt_usable = false;
@@ -217 +219 @@
-    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)
@@ -225 +233 @@
-    }
-
+error:
-    free (s);
-    return NULL;
@@ -441 +450 @@
-/** Message Authentication and Integrity for RTP */
-static const uint8_t *
-
+
+
-{
-    const gcry_md_hd_t md = s->rtp.mac;
-    uint32_t roc = htonl (srtp_compute_roc (s, rtp_seq (data)));
-
-    gcry_md_reset (md);
-    gcry_md_write (md, data, len);
-roc
+(uint32_t){ htonl (roc) }
-    return gcry_md_read (md, 0);
-}
@@ -533 +542 @@
- * @param buf RTP packet to be encrypted/digested
- * @param lenp pointer to the RTP packet length on entry,
-in case of
+on non-ENOSPC
- * @param bufsize size (bytes) of the packet buffer
- *
- * @return 0 on success, in case of error:
- *  EINVAL  malformatted RTP packet or internal error
-
+
+
- *  EACCES  packet would trigger a replay error on receiver
- */
@@ -551 +561 @@
-    if (!(s->flags & SRTP_UNAUTHENTICATED))
-    {
-
+
+
+
-            return ENOSPC;
-
-
-
-
+
+
+
+
+
+
+
+
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+
+
+
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+
+
+
+
+
+
+
-    }
-
@@ -579 +609 @@
-{
-    size_t len = *lenp;
+    if (len < 12u)
+        return EINVAL;
-
-    if (!(s->flags & SRTP_UNAUTHENTICATED))
-    {
-
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
-            return EINVAL;
-
-
-
-
+
+
+
+
+
+
+
+
+
+
+
+
+
+
-            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;
-    }