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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 "libavutil/mathematics.h"
51 #include "oma.h"
52 #include "pcm.h"
53 #include "id3v2.h"
54 
55 
56 static const uint64_t leaf_table[] = {
57  0xd79e8283acea4620, 0x7a9762f445afd0d8,
58  0x354d60a60b8c79f1, 0x584e1cde00b07aee,
59  0x1573cd93da7df623, 0x47f98d79620dd535
60 };
61 
62 typedef struct OMAContext {
63  uint64_t content_start;
64  int encrypted;
65  uint16_t k_size;
66  uint16_t e_size;
67  uint16_t i_size;
68  uint16_t s_size;
69  uint32_t rid;
76  uint8_t iv[8];
77  struct AVDES av_des;
78 } OMAContext;
79 
80 static void hex_log(AVFormatContext *s, int level,
81  const char *name, const uint8_t *value, int len)
82 {
83  char buf[33];
84  len = FFMIN(len, 16);
85  if (av_log_get_level() < level)
86  return;
87  ff_data_to_hex(buf, value, len, 1);
88  buf[len << 1] = '\0';
89  av_log(s, level, "%s: %s\n", name, buf);
90 }
91 
92 static int kset(AVFormatContext *s, const uint8_t *r_val, const uint8_t *n_val,
93  int len)
94 {
95  OMAContext *oc = s->priv_data;
96 
97  if (!r_val && !n_val)
98  return -1;
99 
100  len = FFMIN(len, 16);
101 
102  /* use first 64 bits in the third round again */
103  if (r_val) {
104  if (r_val != oc->r_val) {
105  memset(oc->r_val, 0, 24);
106  memcpy(oc->r_val, r_val, len);
107  }
108  memcpy(&oc->r_val[16], r_val, 8);
109  }
110  if (n_val) {
111  if (n_val != oc->n_val) {
112  memset(oc->n_val, 0, 24);
113  memcpy(oc->n_val, n_val, len);
114  }
115  memcpy(&oc->n_val[16], n_val, 8);
116  }
117 
118  return 0;
119 }
120 
121 #define OMA_RPROBE_M_VAL 48 + 1
122 
123 static int rprobe(AVFormatContext *s, uint8_t *enc_header, unsigned size,
124  const uint8_t *r_val)
125 {
126  OMAContext *oc = s->priv_data;
127  unsigned int pos;
128  struct AVDES av_des;
129 
130  if (!enc_header || !r_val ||
131  size < OMA_ENC_HEADER_SIZE + oc->k_size + oc->e_size + oc->i_size ||
132  size < OMA_RPROBE_M_VAL)
133  return -1;
134 
135  /* m_val */
136  av_des_init(&av_des, r_val, 192, 1);
137  av_des_crypt(&av_des, oc->m_val, &enc_header[48], 1, NULL, 1);
138 
139  /* s_val */
140  av_des_init(&av_des, oc->m_val, 64, 0);
141  av_des_crypt(&av_des, oc->s_val, NULL, 1, NULL, 0);
142 
143  /* sm_val */
144  pos = OMA_ENC_HEADER_SIZE + oc->k_size + oc->e_size;
145  av_des_init(&av_des, oc->s_val, 64, 0);
146  av_des_mac(&av_des, oc->sm_val, &enc_header[pos], (oc->i_size >> 3));
147 
148  pos += oc->i_size;
149 
150  return memcmp(&enc_header[pos], oc->sm_val, 8) ? -1 : 0;
151 }
152 
153 static int nprobe(AVFormatContext *s, uint8_t *enc_header, unsigned size,
154  const uint8_t *n_val)
155 {
156  OMAContext *oc = s->priv_data;
157  uint64_t pos;
158  uint32_t taglen, datalen;
159  struct AVDES av_des;
160 
161  if (!enc_header || !n_val ||
163  return -1;
164 
165  pos = OMA_ENC_HEADER_SIZE + oc->k_size;
166  if (!memcmp(&enc_header[pos], "EKB ", 4))
167  pos += 32;
168 
169  if (size < pos + 44)
170  return -1;
171 
172  if (AV_RB32(&enc_header[pos]) != oc->rid)
173  av_log(s, AV_LOG_DEBUG, "Mismatching RID\n");
174 
175  taglen = AV_RB32(&enc_header[pos + 32]);
176  datalen = AV_RB32(&enc_header[pos + 36]) >> 4;
177 
178  pos += 44LL + taglen;
179 
180  if (pos + (((uint64_t)datalen) << 4) > size)
181  return -1;
182 
183  av_des_init(&av_des, n_val, 192, 1);
184  while (datalen-- > 0) {
185  av_des_crypt(&av_des, oc->r_val, &enc_header[pos], 2, NULL, 1);
186  kset(s, oc->r_val, NULL, 16);
187  if (!rprobe(s, enc_header, size, oc->r_val))
188  return 0;
189  pos += 16;
190  }
191 
192  return -1;
193 }
194 
196 {
197  OMAContext *oc = s->priv_data;
198  ID3v2ExtraMetaGEOB *geob = NULL;
199  uint8_t *gdata;
200 
201  oc->encrypted = 1;
202  av_log(s, AV_LOG_INFO, "File is encrypted\n");
203 
204  /* find GEOB metadata */
205  while (em) {
206  if (!strcmp(em->tag, "GEOB") &&
207  (geob = em->data) &&
208  (!strcmp(geob->description, "OMG_LSI") ||
209  !strcmp(geob->description, "OMG_BKLSI"))) {
210  break;
211  }
212  em = em->next;
213  }
214  if (!em) {
215  av_log(s, AV_LOG_ERROR, "No encryption header found\n");
216  return AVERROR_INVALIDDATA;
217  }
218 
219  if (geob->datasize < 64) {
220  av_log(s, AV_LOG_ERROR,
221  "Invalid GEOB data size: %"PRIu32"\n", geob->datasize);
222  return AVERROR_INVALIDDATA;
223  }
224 
225  gdata = geob->data;
226 
227  if (AV_RB16(gdata) != 1)
228  av_log(s, AV_LOG_WARNING, "Unknown version in encryption header\n");
229 
230  oc->k_size = AV_RB16(&gdata[2]);
231  oc->e_size = AV_RB16(&gdata[4]);
232  oc->i_size = AV_RB16(&gdata[6]);
233  oc->s_size = AV_RB16(&gdata[8]);
234 
235  if (memcmp(&gdata[OMA_ENC_HEADER_SIZE], "KEYRING ", 12)) {
236  av_log(s, AV_LOG_ERROR, "Invalid encryption header\n");
237  return AVERROR_INVALIDDATA;
238  }
239  if (OMA_ENC_HEADER_SIZE + oc->k_size + oc->e_size + oc->i_size + 8 > geob->datasize ||
240  OMA_ENC_HEADER_SIZE + 48 > geob->datasize) {
241  av_log(s, AV_LOG_ERROR, "Too little GEOB data\n");
242  return AVERROR_INVALIDDATA;
243  }
244  oc->rid = AV_RB32(&gdata[OMA_ENC_HEADER_SIZE + 28]);
245  av_log(s, AV_LOG_DEBUG, "RID: %.8"PRIx32"\n", oc->rid);
246 
247  memcpy(oc->iv, &header[0x58], 8);
248  hex_log(s, AV_LOG_DEBUG, "IV", oc->iv, 8);
249 
250  hex_log(s, AV_LOG_DEBUG, "CBC-MAC",
251  &gdata[OMA_ENC_HEADER_SIZE + oc->k_size + oc->e_size + oc->i_size],
252  8);
253 
254  if (s->keylen > 0) {
255  kset(s, s->key, s->key, s->keylen);
256  }
257  if (!memcmp(oc->r_val, (const uint8_t[8]){0}, 8) ||
258  rprobe(s, gdata, geob->datasize, oc->r_val) < 0 &&
259  nprobe(s, gdata, geob->datasize, oc->n_val) < 0) {
260  int i;
261  for (i = 0; i < FF_ARRAY_ELEMS(leaf_table); i += 2) {
262  uint8_t buf[16];
263  AV_WL64(buf, leaf_table[i]);
264  AV_WL64(&buf[8], leaf_table[i + 1]);
265  kset(s, buf, buf, 16);
266  if (!rprobe(s, gdata, geob->datasize, oc->r_val) ||
267  !nprobe(s, gdata, geob->datasize, oc->n_val))
268  break;
269  }
270  if (i >= FF_ARRAY_ELEMS(leaf_table)) {
271  av_log(s, AV_LOG_ERROR, "Invalid key\n");
272  return AVERROR_INVALIDDATA;
273  }
274  }
275 
276  /* e_val */
277  av_des_init(&oc->av_des, oc->m_val, 64, 0);
278  av_des_crypt(&oc->av_des, oc->e_val,
279  &gdata[OMA_ENC_HEADER_SIZE + 40], 1, NULL, 0);
280  hex_log(s, AV_LOG_DEBUG, "EK", oc->e_val, 8);
281 
282  /* init e_val */
283  av_des_init(&oc->av_des, oc->e_val, 64, 1);
284 
285  return 0;
286 }
287 
289 {
290  int ret, framesize, jsflag, samplerate;
291  uint32_t codec_params, channel_id;
292  int16_t eid;
294  uint8_t *edata;
295  AVStream *st;
296  ID3v2ExtraMeta *extra_meta = NULL;
297  OMAContext *oc = s->priv_data;
298 
299  ff_id3v2_read(s, ID3v2_EA3_MAGIC, &extra_meta, 0);
300  ret = avio_read(s->pb, buf, EA3_HEADER_SIZE);
301  if (ret < EA3_HEADER_SIZE)
302  return -1;
303 
304  if (memcmp(buf, ((const uint8_t[]){'E', 'A', '3'}), 3) ||
305  buf[4] != 0 || buf[5] != EA3_HEADER_SIZE) {
306  av_log(s, AV_LOG_ERROR, "Couldn't find the EA3 header !\n");
307  return AVERROR_INVALIDDATA;
308  }
309 
310  oc->content_start = avio_tell(s->pb);
311 
312  /* encrypted file */
313  eid = AV_RB16(&buf[6]);
314  if (eid != -1 && eid != -128 && decrypt_init(s, extra_meta, buf) < 0) {
315  ff_id3v2_free_extra_meta(&extra_meta);
316  return -1;
317  }
318 
319  ff_id3v2_free_extra_meta(&extra_meta);
320 
321  codec_params = AV_RB24(&buf[33]);
322 
323  st = avformat_new_stream(s, NULL);
324  if (!st)
325  return AVERROR(ENOMEM);
326 
327  st->start_time = 0;
329  st->codec->codec_tag = buf[32];
331  st->codec->codec_tag);
332 
333  switch (buf[32]) {
334  case OMA_CODECID_ATRAC3:
335  samplerate = ff_oma_srate_tab[(codec_params >> 13) & 7] * 100;
336  if (!samplerate) {
337  av_log(s, AV_LOG_ERROR, "Unsupported sample rate\n");
338  return AVERROR_INVALIDDATA;
339  }
340  if (samplerate != 44100)
341  avpriv_request_sample(s, "Sample rate %d", samplerate);
342 
343  framesize = (codec_params & 0x3FF) * 8;
344 
345  /* get stereo coding mode, 1 for joint-stereo */
346  jsflag = (codec_params >> 17) & 1;
347 
348  st->codec->channels = 2;
350  st->codec->sample_rate = samplerate;
351  st->codec->bit_rate = st->codec->sample_rate * framesize * 8 / 1024;
352 
353  /* fake the ATRAC3 extradata
354  * (wav format, makes stream copy to wav work) */
355  if (ff_alloc_extradata(st->codec, 14))
356  return AVERROR(ENOMEM);
357 
358  edata = st->codec->extradata;
359  AV_WL16(&edata[0], 1); // always 1
360  AV_WL32(&edata[2], samplerate); // samples rate
361  AV_WL16(&edata[6], jsflag); // coding mode
362  AV_WL16(&edata[8], jsflag); // coding mode
363  AV_WL16(&edata[10], 1); // always 1
364  // AV_WL16(&edata[12], 0); // always 0
365 
366  avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
367  break;
368  case OMA_CODECID_ATRAC3P:
369  channel_id = (codec_params >> 10) & 7;
370  if (!channel_id) {
371  av_log(s, AV_LOG_ERROR,
372  "Invalid ATRAC-X channel id: %"PRIu32"\n", channel_id);
373  return AVERROR_INVALIDDATA;
374  }
375  st->codec->channel_layout = ff_oma_chid_to_native_layout[channel_id - 1];
376  st->codec->channels = ff_oma_chid_to_num_channels[channel_id - 1];
377  framesize = ((codec_params & 0x3FF) * 8) + 8;
378  samplerate = ff_oma_srate_tab[(codec_params >> 13) & 7] * 100;
379  if (!samplerate) {
380  av_log(s, AV_LOG_ERROR, "Unsupported sample rate\n");
381  return AVERROR_INVALIDDATA;
382  }
383  st->codec->sample_rate = samplerate;
384  st->codec->bit_rate = samplerate * framesize * 8 / 2048;
385  avpriv_set_pts_info(st, 64, 1, samplerate);
386  break;
387  case OMA_CODECID_MP3:
389  framesize = 1024;
390  break;
391  case OMA_CODECID_LPCM:
392  /* PCM 44.1 kHz 16 bit stereo big-endian */
393  st->codec->channels = 2;
395  st->codec->sample_rate = 44100;
396  framesize = 1024;
397  /* bit rate = sample rate x PCM block align (= 4) x 8 */
398  st->codec->bit_rate = st->codec->sample_rate * 32;
401  avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
402  break;
403  default:
404  av_log(s, AV_LOG_ERROR, "Unsupported codec %d!\n", buf[32]);
405  return AVERROR(ENOSYS);
406  }
407 
408  st->codec->block_align = framesize;
409 
410  return 0;
411 }
412 
413 
415 {
416  OMAContext *oc = s->priv_data;
417  AVStream *st = s->streams[0];
418  int packet_size = st->codec->block_align;
419  int byte_rate = st->codec->bit_rate >> 3;
420  int64_t pos = avio_tell(s->pb);
421  int ret = av_get_packet(s->pb, pkt, packet_size);
422 
423  if (ret < packet_size)
424  pkt->flags |= AV_PKT_FLAG_CORRUPT;
425 
426  if (ret < 0)
427  return ret;
428  if (!ret)
429  return AVERROR_EOF;
430 
431  pkt->stream_index = 0;
432 
433  if (pos >= oc->content_start && byte_rate > 0) {
434  pkt->pts =
435  pkt->dts = av_rescale(pos - oc->content_start, st->time_base.den,
436  byte_rate * (int64_t)st->time_base.num);
437  }
438 
439  if (oc->encrypted) {
440  /* previous unencrypted block saved in IV for
441  * the next packet (CBC mode) */
442  if (ret == packet_size)
443  av_des_crypt(&oc->av_des, pkt->data, pkt->data,
444  (packet_size >> 3), oc->iv, 1);
445  else
446  memset(oc->iv, 0, 8);
447  }
448 
449  return ret;
450 }
451 
453 {
454  const uint8_t *buf = p->buf;
455  unsigned tag_len = 0;
456 
458  tag_len = ff_id3v2_tag_len(buf);
459 
460  /* This check cannot overflow as tag_len has at most 28 bits */
461  if (p->buf_size < tag_len + 5)
462  /* EA3 header comes late, might be outside of the probe buffer */
463  return tag_len ? AVPROBE_SCORE_EXTENSION/2 : 0;
464 
465  buf += tag_len;
466 
467  if (!memcmp(buf, "EA3", 3) && !buf[4] && buf[5] == EA3_HEADER_SIZE)
468  return AVPROBE_SCORE_MAX;
469  else
470  return 0;
471 }
472 
473 static int oma_read_seek(struct AVFormatContext *s,
474  int stream_index, int64_t timestamp, int flags)
475 {
476  OMAContext *oc = s->priv_data;
477  int64_t err = ff_pcm_read_seek(s, stream_index, timestamp, flags);
478 
479  if (!oc->encrypted)
480  return err;
481 
482  /* readjust IV for CBC */
483  if (err || avio_tell(s->pb) < oc->content_start)
484  goto wipe;
485  if ((err = avio_seek(s->pb, -8, SEEK_CUR)) < 0)
486  goto wipe;
487  if ((err = avio_read(s->pb, oc->iv, 8)) < 8) {
488  if (err >= 0)
489  err = AVERROR_EOF;
490  goto wipe;
491  }
492 
493  return 0;
494 wipe:
495  memset(oc->iv, 0, 8);
496  return err;
497 }
498 
500  .name = "oma",
501  .long_name = NULL_IF_CONFIG_SMALL("Sony OpenMG audio"),
502  .priv_data_size = sizeof(OMAContext),
508  .extensions = "oma,omg,aa3",
509  .codec_tag = (const AVCodecTag* const []){ff_oma_codec_tags, 0},
510 };