Changeset 9c7f833f2441b85d2d959b423f7de30ee59743ff

Timestamp:

03/11/07 15:58:40 (1 year ago)

Author:

Rémi Denis-Courmont <rem@videolan.org>

git-committer:

Rémi Denis-Courmont <rem@videolan.org> 1173625120 +0000

git-parent:

[263b77a37a173ae8ed008b959ae54d1d48f09f77]

git-author:

Rémi Denis-Courmont <rem@videolan.org> 1173625120 +0000

Message:

Leverage libgcrypt CounTeR mode implementation to simplify our code

Files:

• libs/srtp/srtp.c (modified) (4 diffs)
• libs/srtp/test-aes.c (modified) (1 diff)

libs/srtp/srtp.c

@@ -231 +231 @@
-
-/**
+ * Counter Mode encryption/decryption (ctr length = 16 bytes)
+ * with non-padded (truncated) text
+ */
+static int
+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)
- */
@@ -248 +279 @@
-        iv[sizeof (iv) - rlen + i] ^= r[i];
-
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+
-}
-
@@ -306 +316 @@
-    uint8_t r[6];
-
-
-
+
-     || gcry_cipher_setkey (prf, key, keylen))
-        return -1;
@@ -381 +390 @@
-    assert (rate != 0);
-    s->rtp_rcc = rate;
-}
-
-
-/** AES-CM encryption/decryption (ctr length = 16 bytes) */
-static int
-ctr_crypt (gcry_cipher_hd_t hd, uint32_t *ctr, uint8_t *data, size_t len)
-{
-    const size_t ctrlen = 16;
-    while (len >= ctrlen)
-    {
-        if (gcry_cipher_setctr (hd, ctr, ctrlen)
-         || gcry_cipher_encrypt (hd, data, ctrlen, NULL, 0))
-            return -1;
-
-        data += ctrlen;
-        len -= ctrlen;
-        ctr[3] = htonl (ntohl (ctr[3]) + 1);
-    }
-
-    if (len > 0)
-    {
-        /* Truncated last block */
-        uint8_t dummy[ctrlen];
-        memcpy (dummy, data, len);
-        memset (dummy + len, 0, ctrlen - len);
-
-        if (gcry_cipher_setctr (hd, ctr, ctrlen)
-         || gcry_cipher_encrypt (hd, dummy, ctrlen, data, ctrlen))
-            return -1;
-        memcpy (data, dummy, len);
-    }
-
-    return 0;
-}
-

libs/srtp/test-aes.c

@@ -64 +64 @@
-    printhex (salt, sizeof (salt));
-
-ECB
+CTR
-     || gcry_cipher_setkey (prf, key, sizeof (key)))
-        fatal ("Internal PRF error");