@@ -21,7 +21,7 @@ OBJS-$(CONFIG_AMR_DEMUXER)               += amr.o

 OBJS-$(CONFIG_AMR_MUXER)                 += amr.o

 OBJS-$(CONFIG_APC_DEMUXER)               += apc.o

 OBJS-$(CONFIG_APE_DEMUXER)               += ape.o

-OBJS-$(CONFIG_ASF_DEMUXER)               += asf.o riff.o

+OBJS-$(CONFIG_ASF_DEMUXER)               += asf.o asfcrypt.o riff.o

 OBJS-$(CONFIG_ASF_MUXER)                 += asf-enc.o riff.o

 OBJS-$(CONFIG_ASF_STREAM_MUXER)          += asf-enc.o riff.o

 OBJS-$(CONFIG_AU_DEMUXER)                += au.o raw.o

@@ -23,6 +23,7 @@

 #include "mpegaudio.h"

 #include "asf.h"

 #include "common.h"

+#include "asfcrypt.h"

 #undef NDEBUG

 #include <assert.h>

@@ -823,6 +824,9 @@ static int asf_read_packet(AVFormatContext *s, AVPacket *pkt)

         get_buffer(pb, asf_st->pkt.data + asf->packet_frag_offset,

                    asf->packet_frag_size);

+        if (s->key && s->keylen == 20)

+            ff_asfcrypt_dec(s->key, asf_st->pkt.data + asf->packet_frag_offset,

+                            asf->packet_frag_size);

         asf_st->frag_offset += asf->packet_frag_size;

         /* test if whole packet is read */

         if (asf_st->frag_offset == asf_st->pkt.size) {

new file mode 100644

@@ -0,0 +1,172 @@

+/*

+ * ASF decryption

+ * Copyright (c) 2007 Reimar Doeffinger

+ * This is a rewrite of code contained in freeme/freeme2

+ *

+ * 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 "common.h"

+#include "intreadwrite.h"

+#include "bswap.h"

+#include "des.h"

+#include "rc4.h"

+#include "asfcrypt.h"

+

+/**

+ * \brief find multiplicative inverse modulo 2 ^ 32

+ * \param v number to invert, must be odd!

+ * \return number so that result * v = 1 (mod 2^32)

+ */

+static uint32_t inverse(uint32_t v) {

+    // v ^ 3 gives the inverse (mod 16), could also be implemented

+    // as table etc. (only lowest 4 bits matter!)

+    uint32_t inverse = v * v * v;

+    // uses a fixpoint-iteration that doubles the number

+    // of correct lowest bits each time

+    inverse *= 2 - v * inverse;

+    inverse *= 2 - v * inverse;

+    inverse *= 2 - v * inverse;

+    return inverse;

+}

+

+/**

+ * \brief read keys from keybuf into keys

+ * \param keybuf buffer containing the keys

+ * \param keys output key array containing the keys for encryption in

+ *             native endianness

+ */

+static void multiswap_init(const uint8_t keybuf[48], uint32_t keys[12]) {

+    int i;

+    for (i = 0; i < 12; i++)

+        keys[i] = AV_RL32(keybuf + (i << 2)) | 1;

+}

+

+/**

+ * \brief invert the keys so that encryption become decryption keys and

+ *        the other way round.

+ * \param keys key array of ints to invert

+ */

+static void multiswap_invert_keys(uint32_t keys[12]) {

+    int i;

+    for (i = 0; i < 5; i++)

+        keys[i] = inverse(keys[i]);

+    for (i = 6; i < 11; i++)

+        keys[i] = inverse(keys[i]);

+}

+

+static uint32_t multiswap_step(const uint32_t keys[12], uint32_t v) {

+    int i;

+    v *= keys[0];

+    for (i = 1; i < 5; i++) {

+        v = (v >> 16) | (v << 16);

+        v *= keys[i];

+    }

+    v += keys[5];

+    return v;

+}

+

+static uint32_t multiswap_inv_step(const uint32_t keys[12], uint32_t v) {

+    int i;

+    v -= keys[5];

+    for (i = 4; i > 0; i--) {

+        v *= keys[i];

+        v = (v >> 16) | (v << 16);

+    }

+    v *= keys[0];

+    return v;

+}

+

+/**

+ * \brief "MultiSwap" encryption

+ * \param keys 32 bit numbers in machine endianness,

+ *             0-4 and 6-10 must be inverted from decryption

+ * \param key another key, this one must be the same for the decryption

+ * \param data data to encrypt

+ * \return encrypted data

+ */

+static uint64_t multiswap_enc(const uint32_t keys[12], uint64_t key, uint64_t data) {

+    uint32_t a = data;

+    uint32_t b = data >> 32;

+    uint32_t c;

+    uint32_t tmp;

+    a += key;

+    tmp = multiswap_step(keys    , a);

+    b += tmp;

+    c = (key >> 32) + tmp;

+    tmp = multiswap_step(keys + 6, b);

+    c += tmp;

+    return ((uint64_t)c << 32) | tmp;

+}

+

+/**

+ * \brief "MultiSwap" decryption

+ * \param keys 32 bit numbers in machine endianness,

+ *             0-4 and 6-10 must be inverted from encryption

+ * \param key another key, this one must be the same as for the encryption

+ * \param data data to decrypt

+ * \return decrypted data

+ */

+static uint64_t multiswap_dec(const uint32_t keys[12], uint64_t key, uint64_t data) {

+    uint32_t a;

+    uint32_t b;

+    uint32_t c = data >> 32;

+    uint32_t tmp = data;

+    c -= tmp;

+    b = multiswap_inv_step(keys + 6, tmp);

+    tmp = c - (key >> 32);

+    b -= tmp;

+    a = multiswap_inv_step(keys    , tmp);

+    a -= key;

+    return ((uint64_t)b << 32) | a;

+}

+

+void ff_asfcrypt_dec(const uint8_t key[20], uint8_t *data, int len) {

+    int num_qwords = len >> 3;

+    uint64_t *qwords = (uint64_t *)data;

+    uint64_t rc4buff[8];

+    uint64_t packetkey;

+    uint32_t ms_keys[12];

+    uint64_t ms_state;

+    int i;

+    if (len < 16) {

+        for (i = 0; i < len; i++)

+            data[i] ^= key[i];

+        return;

+    }

+

+    memset(rc4buff, 0, sizeof(rc4buff));

+    ff_rc4_enc(key, 12, (uint8_t *)rc4buff, sizeof(rc4buff));

+    multiswap_init((uint8_t *)rc4buff, ms_keys);

+

+    packetkey = qwords[num_qwords - 1];

+    packetkey ^= rc4buff[7];

+    packetkey = be2me_64(packetkey);

+    packetkey = ff_des_encdec(packetkey, AV_RB64(key + 12), 1);

+    packetkey = be2me_64(packetkey);

+    packetkey ^= rc4buff[6];

+

+    ff_rc4_enc((uint8_t *)&packetkey, 8, data, len);

+

+    ms_state = 0;

+    for (i = 0; i < num_qwords - 1; i++, qwords++)

+        ms_state = multiswap_enc(ms_keys, ms_state, AV_RL64(qwords));

+    multiswap_invert_keys(ms_keys);

+    packetkey = (packetkey << 32) | (packetkey >> 32);

+    packetkey = le2me_64(packetkey);

+    packetkey = multiswap_dec(ms_keys, ms_state, packetkey);

+    AV_WL64(qwords, packetkey);

+}

new file mode 100644

@@ -0,0 +1,27 @@

+/*

+ * ASF decryption

+ * Copyright (c) 2007 Reimar Doeffinger

+ *

+ * 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

+ */

+

+#ifndef FFMPEG_ASFCRYPT_H

+#define FFMPEG_ASFCRYPT_H

+

+void ff_asfcrypt_dec(const uint8_t key[20], uint8_t *data, int len);

+

+#endif