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omadec.c
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1 /*
2  * Sony OpenMG (OMA) demuxer
3  *
4  * Copyright (c) 2008, 2013 Maxim Poliakovski
5  * 2008 Benjamin Larsson
6  * 2011 David Goldwich
7  *
8  * This file is part of FFmpeg.
9  *
10  * FFmpeg is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU Lesser General Public
12  * License as published by the Free Software Foundation; either
13  * version 2.1 of the License, or (at your option) any later version.
14  *
15  * FFmpeg is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18  * Lesser General Public License for more details.
19  *
20  * You should have received a copy of the GNU Lesser General Public
21  * License along with FFmpeg; if not, write to the Free Software
22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23  */
24 
25 /**
26  * @file
27  * This is a demuxer for Sony OpenMG Music files
28  *
29  * Known file extensions: ".oma", "aa3"
30  * The format of such files consists of three parts:
31  * - "ea3" header carrying overall info and metadata. Except for starting with
32  * "ea" instead of "ID", it's an ID3v2 header.
33  * - "EA3" header is a Sony-specific header containing information about
34  * the OpenMG file: codec type (usually ATRAC, can also be MP3 or WMA),
35  * codec specific info (packet size, sample rate, channels and so on)
36  * and DRM related info (file encryption, content id).
37  * - Sound data organized in packets follow the EA3 header
38  * (can be encrypted using the Sony DRM!).
39  *
40  * Supported decoders: ATRAC3, ATRAC3+, MP3, LPCM
41  */
42 
43 #include <inttypes.h>
44 
46 #include "avformat.h"
47 #include "internal.h"
48 #include "libavutil/intreadwrite.h"
49 #include "libavutil/des.h"
50 #include "oma.h"
51 #include "pcm.h"
52 #include "id3v2.h"
53 
54 
55 static const uint64_t leaf_table[] = {
56  0xd79e8283acea4620, 0x7a9762f445afd0d8,
57  0x354d60a60b8c79f1, 0x584e1cde00b07aee,
58  0x1573cd93da7df623, 0x47f98d79620dd535
59 };
60 
61 typedef struct OMAContext {
62  uint64_t content_start;
63  int encrypted;
64  uint16_t k_size;
65  uint16_t e_size;
66  uint16_t i_size;
67  uint16_t s_size;
68  uint32_t rid;
75  uint8_t iv[8];
76  struct AVDES av_des;
77 } OMAContext;
78 
79 static void hex_log(AVFormatContext *s, int level,
80  const char *name, const uint8_t *value, int len)
81 {
82  char buf[33];
83  len = FFMIN(len, 16);
84  if (av_log_get_level() < level)
85  return;
86  ff_data_to_hex(buf, value, len, 1);
87  buf[len << 1] = '\0';
88  av_log(s, level, "%s: %s\n", name, buf);
89 }
90 
91 static int kset(AVFormatContext *s, const uint8_t *r_val, const uint8_t *n_val,
92  int len)
93 {
94  OMAContext *oc = s->priv_data;
95 
96  if (!r_val && !n_val)
97  return -1;
98 
99  len = FFMIN(len, 16);
100 
101  /* use first 64 bits in the third round again */
102  if (r_val) {
103  if (r_val != oc->r_val) {
104  memset(oc->r_val, 0, 24);
105  memcpy(oc->r_val, r_val, len);
106  }
107  memcpy(&oc->r_val[16], r_val, 8);
108  }
109  if (n_val) {
110  if (n_val != oc->n_val) {
111  memset(oc->n_val, 0, 24);
112  memcpy(oc->n_val, n_val, len);
113  }
114  memcpy(&oc->n_val[16], n_val, 8);
115  }
116 
117  return 0;
118 }
119 
120 #define OMA_RPROBE_M_VAL 48 + 1
121 
122 static int rprobe(AVFormatContext *s, uint8_t *enc_header, unsigned size,
123  const uint8_t *r_val)
124 {
125  OMAContext *oc = s->priv_data;
126  unsigned int pos;
127  struct AVDES av_des;
128 
129  if (!enc_header || !r_val ||
130  size < OMA_ENC_HEADER_SIZE + oc->k_size + oc->e_size + oc->i_size ||
131  size < OMA_RPROBE_M_VAL)
132  return -1;
133 
134  /* m_val */
135  av_des_init(&av_des, r_val, 192, 1);
136  av_des_crypt(&av_des, oc->m_val, &enc_header[48], 1, NULL, 1);
137 
138  /* s_val */
139  av_des_init(&av_des, oc->m_val, 64, 0);
140  av_des_crypt(&av_des, oc->s_val, NULL, 1, NULL, 0);
141 
142  /* sm_val */
143  pos = OMA_ENC_HEADER_SIZE + oc->k_size + oc->e_size;
144  av_des_init(&av_des, oc->s_val, 64, 0);
145  av_des_mac(&av_des, oc->sm_val, &enc_header[pos], (oc->i_size >> 3));
146 
147  pos += oc->i_size;
148 
149  return memcmp(&enc_header[pos], oc->sm_val, 8) ? -1 : 0;
150 }
151 
152 static int nprobe(AVFormatContext *s, uint8_t *enc_header, unsigned size,
153  const uint8_t *n_val)
154 {
155  OMAContext *oc = s->priv_data;
156  uint64_t pos;
157  uint32_t taglen, datalen;
158  struct AVDES av_des;
159 
160  if (!enc_header || !n_val ||
162  return -1;
163 
164  pos = OMA_ENC_HEADER_SIZE + oc->k_size;
165  if (!memcmp(&enc_header[pos], "EKB ", 4))
166  pos += 32;
167 
168  if (size < pos + 44)
169  return -1;
170 
171  if (AV_RB32(&enc_header[pos]) != oc->rid)
172  av_log(s, AV_LOG_DEBUG, "Mismatching RID\n");
173 
174  taglen = AV_RB32(&enc_header[pos + 32]);
175  datalen = AV_RB32(&enc_header[pos + 36]) >> 4;
176 
177  pos += 44L + taglen;
178 
179  if (pos + (((uint64_t)datalen) << 4) > size)
180  return -1;
181 
182  av_des_init(&av_des, n_val, 192, 1);
183  while (datalen-- > 0) {
184  av_des_crypt(&av_des, oc->r_val, &enc_header[pos], 2, NULL, 1);
185  kset(s, oc->r_val, NULL, 16);
186  if (!rprobe(s, enc_header, size, oc->r_val))
187  return 0;
188  pos += 16;
189  }
190 
191  return -1;
192 }
193 
195 {
196  OMAContext *oc = s->priv_data;
197  ID3v2ExtraMetaGEOB *geob = NULL;
198  uint8_t *gdata;
199 
200  oc->encrypted = 1;
201  av_log(s, AV_LOG_INFO, "File is encrypted\n");
202 
203  /* find GEOB metadata */
204  while (em) {
205  if (!strcmp(em->tag, "GEOB") &&
206  (geob = em->data) &&
207  (!strcmp(geob->description, "OMG_LSI") ||
208  !strcmp(geob->description, "OMG_BKLSI"))) {
209  break;
210  }
211  em = em->next;
212  }
213  if (!em) {
214  av_log(s, AV_LOG_ERROR, "No encryption header found\n");
215  return AVERROR_INVALIDDATA;
216  }
217 
218  if (geob->datasize < 64) {
219  av_log(s, AV_LOG_ERROR,
220  "Invalid GEOB data size: %"PRIu32"\n", geob->datasize);
221  return AVERROR_INVALIDDATA;
222  }
223 
224  gdata = geob->data;
225 
226  if (AV_RB16(gdata) != 1)
227  av_log(s, AV_LOG_WARNING, "Unknown version in encryption header\n");
228 
229  oc->k_size = AV_RB16(&gdata[2]);
230  oc->e_size = AV_RB16(&gdata[4]);
231  oc->i_size = AV_RB16(&gdata[6]);
232  oc->s_size = AV_RB16(&gdata[8]);
233 
234  if (memcmp(&gdata[OMA_ENC_HEADER_SIZE], "KEYRING ", 12)) {
235  av_log(s, AV_LOG_ERROR, "Invalid encryption header\n");
236  return AVERROR_INVALIDDATA;
237  }
238  if (OMA_ENC_HEADER_SIZE + oc->k_size + oc->e_size + oc->i_size + 8 > geob->datasize ||
239  OMA_ENC_HEADER_SIZE + 48 > geob->datasize) {
240  av_log(s, AV_LOG_ERROR, "Too little GEOB data\n");
241  return AVERROR_INVALIDDATA;
242  }
243  oc->rid = AV_RB32(&gdata[OMA_ENC_HEADER_SIZE + 28]);
244  av_log(s, AV_LOG_DEBUG, "RID: %.8"PRIx32"\n", oc->rid);
245 
246  memcpy(oc->iv, &header[0x58], 8);
247  hex_log(s, AV_LOG_DEBUG, "IV", oc->iv, 8);
248 
249  hex_log(s, AV_LOG_DEBUG, "CBC-MAC",
250  &gdata[OMA_ENC_HEADER_SIZE + oc->k_size + oc->e_size + oc->i_size],
251  8);
252 
253  if (s->keylen > 0) {
254  kset(s, s->key, s->key, s->keylen);
255  }
256  if (!memcmp(oc->r_val, (const uint8_t[8]){0}, 8) ||
257  rprobe(s, gdata, geob->datasize, oc->r_val) < 0 &&
258  nprobe(s, gdata, geob->datasize, oc->n_val) < 0) {
259  int i;
260  for (i = 0; i < FF_ARRAY_ELEMS(leaf_table); i += 2) {
261  uint8_t buf[16];
262  AV_WL64(buf, leaf_table[i]);
263  AV_WL64(&buf[8], leaf_table[i + 1]);
264  kset(s, buf, buf, 16);
265  if (!rprobe(s, gdata, geob->datasize, oc->r_val) ||
266  !nprobe(s, gdata, geob->datasize, oc->n_val))
267  break;
268  }
269  if (i >= FF_ARRAY_ELEMS(leaf_table)) {
270  av_log(s, AV_LOG_ERROR, "Invalid key\n");
271  return AVERROR_INVALIDDATA;
272  }
273  }
274 
275  /* e_val */
276  av_des_init(&oc->av_des, oc->m_val, 64, 0);
277  av_des_crypt(&oc->av_des, oc->e_val,
278  &gdata[OMA_ENC_HEADER_SIZE + 40], 1, NULL, 0);
279  hex_log(s, AV_LOG_DEBUG, "EK", oc->e_val, 8);
280 
281  /* init e_val */
282  av_des_init(&oc->av_des, oc->e_val, 64, 1);
283 
284  return 0;
285 }
286 
288 {
289  int ret, framesize, jsflag, samplerate;
290  uint32_t codec_params, channel_id;
291  int16_t eid;
293  uint8_t *edata;
294  AVStream *st;
295  ID3v2ExtraMeta *extra_meta = NULL;
296  OMAContext *oc = s->priv_data;
297 
298  ff_id3v2_read(s, ID3v2_EA3_MAGIC, &extra_meta, 0);
299  ret = avio_read(s->pb, buf, EA3_HEADER_SIZE);
300  if (ret < EA3_HEADER_SIZE)
301  return -1;
302 
303  if (memcmp(buf, ((const uint8_t[]){'E', 'A', '3'}), 3) ||
304  buf[4] != 0 || buf[5] != EA3_HEADER_SIZE) {
305  av_log(s, AV_LOG_ERROR, "Couldn't find the EA3 header !\n");
306  return AVERROR_INVALIDDATA;
307  }
308 
309  oc->content_start = avio_tell(s->pb);
310 
311  /* encrypted file */
312  eid = AV_RB16(&buf[6]);
313  if (eid != -1 && eid != -128 && decrypt_init(s, extra_meta, buf) < 0) {
314  ff_id3v2_free_extra_meta(&extra_meta);
315  return -1;
316  }
317 
318  ff_id3v2_free_extra_meta(&extra_meta);
319 
320  codec_params = AV_RB24(&buf[33]);
321 
322  st = avformat_new_stream(s, NULL);
323  if (!st)
324  return AVERROR(ENOMEM);
325 
326  st->start_time = 0;
328  st->codec->codec_tag = buf[32];
330  st->codec->codec_tag);
331 
332  switch (buf[32]) {
333  case OMA_CODECID_ATRAC3:
334  samplerate = ff_oma_srate_tab[(codec_params >> 13) & 7] * 100;
335  if (!samplerate) {
336  av_log(s, AV_LOG_ERROR, "Unsupported sample rate\n");
337  return AVERROR_INVALIDDATA;
338  }
339  if (samplerate != 44100)
340  avpriv_request_sample(s, "Sample rate %d", samplerate);
341 
342  framesize = (codec_params & 0x3FF) * 8;
343 
344  /* get stereo coding mode, 1 for joint-stereo */
345  jsflag = (codec_params >> 17) & 1;
346 
347  st->codec->channels = 2;
349  st->codec->sample_rate = samplerate;
350  st->codec->bit_rate = st->codec->sample_rate * framesize * 8 / 1024;
351 
352  /* fake the ATRAC3 extradata
353  * (wav format, makes stream copy to wav work) */
354  if (ff_alloc_extradata(st->codec, 14))
355  return AVERROR(ENOMEM);
356 
357  edata = st->codec->extradata;
358  AV_WL16(&edata[0], 1); // always 1
359  AV_WL32(&edata[2], samplerate); // samples rate
360  AV_WL16(&edata[6], jsflag); // coding mode
361  AV_WL16(&edata[8], jsflag); // coding mode
362  AV_WL16(&edata[10], 1); // always 1
363  // AV_WL16(&edata[12], 0); // always 0
364 
365  avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
366  break;
367  case OMA_CODECID_ATRAC3P:
368  channel_id = (codec_params >> 10) & 7;
369  if (!channel_id) {
370  av_log(s, AV_LOG_ERROR,
371  "Invalid ATRAC-X channel id: %"PRIu32"\n", channel_id);
372  return AVERROR_INVALIDDATA;
373  }
374  st->codec->channel_layout = ff_oma_chid_to_native_layout[channel_id - 1];
375  st->codec->channels = ff_oma_chid_to_num_channels[channel_id - 1];
376  framesize = ((codec_params & 0x3FF) * 8) + 8;
377  samplerate = ff_oma_srate_tab[(codec_params >> 13) & 7] * 100;
378  if (!samplerate) {
379  av_log(s, AV_LOG_ERROR, "Unsupported sample rate\n");
380  return AVERROR_INVALIDDATA;
381  }
382  st->codec->sample_rate = samplerate;
383  st->codec->bit_rate = samplerate * framesize * 8 / 2048;
384  avpriv_set_pts_info(st, 64, 1, samplerate);
385  break;
386  case OMA_CODECID_MP3:
388  framesize = 1024;
389  break;
390  case OMA_CODECID_LPCM:
391  /* PCM 44.1 kHz 16 bit stereo big-endian */
392  st->codec->channels = 2;
394  st->codec->sample_rate = 44100;
395  framesize = 1024;
396  /* bit rate = sample rate x PCM block align (= 4) x 8 */
397  st->codec->bit_rate = st->codec->sample_rate * 32;
400  avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
401  break;
402  default:
403  av_log(s, AV_LOG_ERROR, "Unsupported codec %d!\n", buf[32]);
404  return AVERROR(ENOSYS);
405  }
406 
407  st->codec->block_align = framesize;
408 
409  return 0;
410 }
411 
412 
414 {
415  OMAContext *oc = s->priv_data;
416  int packet_size = s->streams[0]->codec->block_align;
417  int ret = av_get_packet(s->pb, pkt, packet_size);
418 
419  if (ret < packet_size)
420  pkt->flags |= AV_PKT_FLAG_CORRUPT;
421 
422  if (ret < 0)
423  return ret;
424  if (!ret)
425  return AVERROR_EOF;
426 
427  pkt->stream_index = 0;
428 
429  if (oc->encrypted) {
430  /* previous unencrypted block saved in IV for
431  * the next packet (CBC mode) */
432  if (ret == packet_size)
433  av_des_crypt(&oc->av_des, pkt->data, pkt->data,
434  (packet_size >> 3), oc->iv, 1);
435  else
436  memset(oc->iv, 0, 8);
437  }
438 
439  return ret;
440 }
441 
443 {
444  const uint8_t *buf = p->buf;
445  unsigned tag_len = 0;
446 
448  tag_len = ff_id3v2_tag_len(buf);
449 
450  /* This check cannot overflow as tag_len has at most 28 bits */
451  if (p->buf_size < tag_len + 5)
452  /* EA3 header comes late, might be outside of the probe buffer */
453  return tag_len ? AVPROBE_SCORE_EXTENSION/2 : 0;
454 
455  buf += tag_len;
456 
457  if (!memcmp(buf, "EA3", 3) && !buf[4] && buf[5] == EA3_HEADER_SIZE)
458  return AVPROBE_SCORE_MAX;
459  else
460  return 0;
461 }
462 
463 static int oma_read_seek(struct AVFormatContext *s,
464  int stream_index, int64_t timestamp, int flags)
465 {
466  OMAContext *oc = s->priv_data;
467  int err = ff_pcm_read_seek(s, stream_index, timestamp, flags);
468 
469  if (!oc->encrypted)
470  return err;
471 
472  /* readjust IV for CBC */
473  if (err || avio_tell(s->pb) < oc->content_start)
474  goto wipe;
475  if ((err = avio_seek(s->pb, -8, SEEK_CUR)) < 0)
476  goto wipe;
477  if ((err = avio_read(s->pb, oc->iv, 8)) < 8) {
478  if (err >= 0)
479  err = AVERROR_EOF;
480  goto wipe;
481  }
482 
483  return 0;
484 wipe:
485  memset(oc->iv, 0, 8);
486  return err;
487 }
488 
490  .name = "oma",
491  .long_name = NULL_IF_CONFIG_SMALL("Sony OpenMG audio"),
492  .priv_data_size = sizeof(OMAContext),
498  .extensions = "oma,omg,aa3",
499  .codec_tag = (const AVCodecTag* const []){ff_oma_codec_tags, 0},
500 };