Implement Realmedia/RTSP-compatible SETUP command. This includes calculation

of the "RealChallenge2" response, which is some sort of authentication. See
discussion in "Realmedia patch" thread on ffmpeg-devel.

Originally committed as revision 15170 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 73 insertions, 0 deletions

diff --git a/libavformat/rdt.c b/libavformat/rdt.c
new file mode 100644
index 0000000000..1d0e4559d0
--- /dev/null
+++ b/libavformat/rdt.c
@@ -0,0 +1,73 @@
+/*
+ * Realmedia RTSP protocol (RDT) support.
+ * Copyright (c) 2007 Ronald S. Bultje
+ *
+ * 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
+ */
+
+/**
+ * @file rdt.c
+ * @brief Realmedia RTSP protocol (RDT) support
+ * @author Ronald S. Bultje <rbultje@ronald.bitfreak.net>
+ */
+
+#include "avformat.h"
+#include "libavutil/avstring.h"
+#include "rdt.h"
+#include "libavutil/base64.h"
+#include "libavutil/md5.h"
+#include "rm.h"
+#include "internal.h"
+
+void
+ff_rdt_calc_response_and_checksum(char response[41], char chksum[9],
+                                  const char *challenge)
+{
+    int ch_len = strlen (challenge), i;
+    unsigned char zres[16],
+        buf[64] = { 0xa1, 0xe9, 0x14, 0x9d, 0x0e, 0x6b, 0x3b, 0x59 };
+#define XOR_TABLE_SIZE 37
+    const unsigned char xor_table[XOR_TABLE_SIZE] = {
+        0x05, 0x18, 0x74, 0xd0, 0x0d, 0x09, 0x02, 0x53,
+        0xc0, 0x01, 0x05, 0x05, 0x67, 0x03, 0x19, 0x70,
+        0x08, 0x27, 0x66, 0x10, 0x10, 0x72, 0x08, 0x09,
+        0x63, 0x11, 0x03, 0x71, 0x08, 0x08, 0x70, 0x02,
+        0x10, 0x57, 0x05, 0x18, 0x54 };
+
+    /* some (length) checks */
+    if (ch_len == 40) /* what a hack... */
+        ch_len = 32;
+    else if (ch_len > 56)
+        ch_len = 56;
+    memcpy(buf + 8, challenge, ch_len);
+
+    /* xor challenge bytewise with xor_table */
+    for (i = 0; i < XOR_TABLE_SIZE; i++)
+        buf[8 + i] ^= xor_table[i];
+
+    av_md5_sum(zres, buf, 64);
+    ff_data_to_hex(response, zres, 16);
+    for (i=0;i<32;i++) response[i] = tolower(response[i]);
+
+    /* add tail */
+    strcpy (response + 32, "01d0a8e3");
+
+    /* calculate checksum */
+    for (i = 0; i < 8; i++)
+        chksum[i] = response[i * 4];
+    chksum[8] = 0;
+}