FFmpeg: libavformat/omadec.c Source File

FFmpeg
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  */
41 
42 #include "libavutil/channel_layout.h"
43 #include "avformat.h"
44 #include "internal.h"
45 #include "libavutil/intreadwrite.h"
46 #include "libavutil/des.h"
47 #include "oma.h"
48 #include "pcm.h"
49 #include "id3v2.h"
50 
51 
52  static const uint64_t leaf_table[] = {
53  0xd79e8283acea4620, 0x7a9762f445afd0d8,
54  0x354d60a60b8c79f1, 0x584e1cde00b07aee,
55  0x1573cd93da7df623, 0x47f98d79620dd535
56 };
57 
58  typedef struct OMAContext {
59   uint64_t content_start;
60   int encrypted;
61   uint16_t k_size;
62   uint16_t e_size;
63   uint16_t i_size;
64   uint16_t s_size;
65   uint32_t rid;
66   uint8_t r_val[24];
67   uint8_t n_val[24];
68   uint8_t m_val[8];
69   uint8_t s_val[8];
70   uint8_t sm_val[8];
71   uint8_t e_val[8];
72   uint8_t iv[8];
73   struct AVDES av_des;
74 } OMAContext;
75 
76  static void hex_log(AVFormatContext *s, int level,
77  const char *name, const uint8_t *value, int len)
78 {
79  char buf[33];
80  len = FFMIN(len, 16);
81  if (av_log_get_level() < level)
82  return;
83  ff_data_to_hex(buf, value, len, 1);
84  buf[len << 1] = '0円';
85  av_log(s, level, "%s: %s\n", name, buf);
86 }
87 
88  static int kset(AVFormatContext *s, const uint8_t *r_val, const uint8_t *n_val,
89  int len)
90 {
91  OMAContext *oc = s->priv_data;
92 
93  if (!r_val && !n_val)
94  return -1;
95 
96  len = FFMIN(len, 16);
97 
98  /* use first 64 bits in the third round again */
99  if (r_val) {
100  if (r_val != oc->r_val) {
101  memset(oc->r_val, 0, 24);
102  memcpy(oc->r_val, r_val, len);
103  }
104  memcpy(&oc->r_val[16], r_val, 8);
105  }
106  if (n_val) {
107  if (n_val != oc->n_val) {
108  memset(oc->n_val, 0, 24);
109  memcpy(oc->n_val, n_val, len);
110  }
111  memcpy(&oc->n_val[16], n_val, 8);
112  }
113 
114  return 0;
115 }
116 
117  #define OMA_RPROBE_M_VAL 48 + 1
118 
119  static int rprobe(AVFormatContext *s, uint8_t *enc_header, unsigned size,
120  const uint8_t *r_val)
121 {
122  OMAContext *oc = s->priv_data;
123  unsigned int pos;
124  struct AVDES av_des;
125 
126  if (!enc_header || !r_val ||
127  size < OMA_ENC_HEADER_SIZE + oc->k_size + oc->e_size + oc->i_size ||
128  size < OMA_RPROBE_M_VAL)
129  return -1;
130 
131  /* m_val */
132  av_des_init(&av_des, r_val, 192, 1);
133  av_des_crypt(&av_des, oc->m_val, &enc_header[48], 1, NULL, 1);
134 
135  /* s_val */
136  av_des_init(&av_des, oc->m_val, 64, 0);
137  av_des_crypt(&av_des, oc->s_val, NULL, 1, NULL, 0);
138 
139  /* sm_val */
140  pos = OMA_ENC_HEADER_SIZE + oc->k_size + oc->e_size;
141  av_des_init(&av_des, oc->s_val, 64, 0);
142  av_des_mac(&av_des, oc->sm_val, &enc_header[pos], (oc->i_size >> 3));
143 
144  pos += oc->i_size;
145 
146  return memcmp(&enc_header[pos], oc->sm_val, 8) ? -1 : 0;
147 }
148 
149  static int nprobe(AVFormatContext *s, uint8_t *enc_header, unsigned size,
150  const uint8_t *n_val)
151 {
152  OMAContext *oc = s->priv_data;
153  uint64_t pos;
154  uint32_t taglen, datalen;
155  struct AVDES av_des;
156 
157  if (!enc_header || !n_val ||
158  size < OMA_ENC_HEADER_SIZE + oc->k_size + 4)
159  return -1;
160 
161  pos = OMA_ENC_HEADER_SIZE + oc->k_size;
162  if (!memcmp(&enc_header[pos], "EKB ", 4))
163  pos += 32;
164 
165  if (size < pos + 44)
166  return -1;
167 
168  if (AV_RB32(&enc_header[pos]) != oc->rid)
169  av_log(s, AV_LOG_DEBUG, "Mismatching RID\n");
170 
171  taglen = AV_RB32(&enc_header[pos + 32]);
172  datalen = AV_RB32(&enc_header[pos + 36]) >> 4;
173 
174  pos += 44L + taglen;
175 
176  if (pos + (((uint64_t)datalen) << 4) > size)
177  return -1;
178 
179  av_des_init(&av_des, n_val, 192, 1);
180  while (datalen-- > 0) {
181  av_des_crypt(&av_des, oc->r_val, &enc_header[pos], 2, NULL, 1);
182  kset(s, oc->r_val, NULL, 16);
183  if (!rprobe(s, enc_header, size, oc->r_val))
184  return 0;
185  pos += 16;
186  }
187 
188  return -1;
189 }
190 
191  static int decrypt_init(AVFormatContext *s, ID3v2ExtraMeta *em, uint8_t *header)
192 {
193  OMAContext *oc = s->priv_data;
194  ID3v2ExtraMetaGEOB *geob = NULL;
195  uint8_t *gdata;
196 
197  oc->encrypted = 1;
198  av_log(s, AV_LOG_INFO, "File is encrypted\n");
199 
200  /* find GEOB metadata */
201  while (em) {
202  if (!strcmp(em->tag, "GEOB") &&
203  (geob = em->data) &&
204  (!strcmp(geob->description, "OMG_LSI") ||
205  !strcmp(geob->description, "OMG_BKLSI"))) {
206  break;
207  }
208  em = em->next;
209  }
210  if (!em) {
211  av_log(s, AV_LOG_ERROR, "No encryption header found\n");
212  return AVERROR_INVALIDDATA;
213  }
214 
215  if (geob->datasize < 64) {
216  av_log(s, AV_LOG_ERROR,
217  "Invalid GEOB data size: %u\n", geob->datasize);
218  return AVERROR_INVALIDDATA;
219  }
220 
221  gdata = geob->data;
222 
223  if (AV_RB16(gdata) != 1)
224  av_log(s, AV_LOG_WARNING, "Unknown version in encryption header\n");
225 
226  oc->k_size = AV_RB16(&gdata[2]);
227  oc->e_size = AV_RB16(&gdata[4]);
228  oc->i_size = AV_RB16(&gdata[6]);
229  oc->s_size = AV_RB16(&gdata[8]);
230 
231  if (memcmp(&gdata[OMA_ENC_HEADER_SIZE], "KEYRING ", 12)) {
232  av_log(s, AV_LOG_ERROR, "Invalid encryption header\n");
233  return AVERROR_INVALIDDATA;
234  }
235  if ( OMA_ENC_HEADER_SIZE + oc->k_size + oc->e_size + oc->i_size + 8 > geob->datasize
236  || OMA_ENC_HEADER_SIZE + 48 > geob->datasize
237  ) {
238  av_log(s, AV_LOG_ERROR, "Too little GEOB data\n");
239  return AVERROR_INVALIDDATA;
240  }
241  oc->rid = AV_RB32(&gdata[OMA_ENC_HEADER_SIZE + 28]);
242  av_log(s, AV_LOG_DEBUG, "RID: %.8x\n", oc->rid);
243 
244  memcpy(oc->iv, &header[0x58], 8);
245  hex_log(s, AV_LOG_DEBUG, "IV", oc->iv, 8);
246 
247  hex_log(s, AV_LOG_DEBUG, "CBC-MAC",
248  &gdata[OMA_ENC_HEADER_SIZE + oc->k_size + oc->e_size + oc->i_size],
249  8);
250 
251  if (s->keylen > 0) {
252  kset(s, s->key, s->key, s->keylen);
253  }
254  if (!memcmp(oc->r_val, (const uint8_t[8]){0}, 8) ||
255  rprobe(s, gdata, geob->datasize, oc->r_val) < 0 &&
256  nprobe(s, gdata, geob->datasize, oc->n_val) < 0) {
257  int i;
258  for (i = 0; i < FF_ARRAY_ELEMS(leaf_table); i += 2) {
259  uint8_t buf[16];
260  AV_WL64(buf, leaf_table[i]);
261  AV_WL64(&buf[8], leaf_table[i + 1]);
262  kset(s, buf, buf, 16);
263  if (!rprobe(s, gdata, geob->datasize, oc->r_val) ||
264  !nprobe(s, gdata, geob->datasize, oc->n_val))
265  break;
266  }
267  if (i >= FF_ARRAY_ELEMS(leaf_table)) {
268  av_log(s, AV_LOG_ERROR, "Invalid key\n");
269  return AVERROR_INVALIDDATA;
270  }
271  }
272 
273  /* e_val */
274  av_des_init(&oc->av_des, oc->m_val, 64, 0);
275  av_des_crypt(&oc->av_des, oc->e_val,
276  &gdata[OMA_ENC_HEADER_SIZE + 40], 1, NULL, 0);
277  hex_log(s, AV_LOG_DEBUG, "EK", oc->e_val, 8);
278 
279  /* init e_val */
280  av_des_init(&oc->av_des, oc->e_val, 64, 1);
281 
282  return 0;
283 }
284 
285  static int oma_read_header(AVFormatContext *s)
286 {
287  int ret, framesize, jsflag, samplerate;
288  uint32_t codec_params, channel_id;
289  int16_t eid;
290  uint8_t buf[EA3_HEADER_SIZE];
291  uint8_t *edata;
292  AVStream *st;
293  ID3v2ExtraMeta *extra_meta = NULL;
294  OMAContext *oc = s->priv_data;
295 
296  ff_id3v2_read(s, ID3v2_EA3_MAGIC, &extra_meta);
297  ret = avio_read(s->pb, buf, EA3_HEADER_SIZE);
298  if (ret < EA3_HEADER_SIZE)
299  return -1;
300 
301  if (memcmp(buf, ((const uint8_t[]){'E', 'A', '3'}), 3) ||
302  buf[4] != 0 || buf[5] != EA3_HEADER_SIZE) {
303  av_log(s, AV_LOG_ERROR, "Couldn't find the EA3 header !\n");
304  return AVERROR_INVALIDDATA;
305  }
306 
307  oc->content_start = avio_tell(s->pb);
308 
309  /* encrypted file */
310  eid = AV_RB16(&buf[6]);
311  if (eid != -1 && eid != -128 && decrypt_init(s, extra_meta, buf) < 0) {
312  ff_id3v2_free_extra_meta(&extra_meta);
313  return -1;
314  }
315 
316  ff_id3v2_free_extra_meta(&extra_meta);
317 
318  codec_params = AV_RB24(&buf[33]);
319 
320  st = avformat_new_stream(s, NULL);
321  if (!st)
322  return AVERROR(ENOMEM);
323 
324  st->start_time = 0;
325  st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
326  st->codec->codec_tag = buf[32];
327  st->codec->codec_id = ff_codec_get_id(ff_oma_codec_tags,
328  st->codec->codec_tag);
329 
330  switch (buf[32]) {
331  case OMA_CODECID_ATRAC3:
332  samplerate = ff_oma_srate_tab[(codec_params >> 13) & 7] * 100;
333  if (!samplerate) {
334  av_log(s, AV_LOG_ERROR, "Unsupported sample rate\n");
335  return AVERROR_INVALIDDATA;
336  }
337  if (samplerate != 44100)
338  avpriv_request_sample(s, "Sample rate %d", samplerate);
339 
340  framesize = (codec_params & 0x3FF) * 8;
341 
342  /* get stereo coding mode, 1 for joint-stereo */
343  jsflag = (codec_params >> 17) & 1;
344 
345  st->codec->channels = 2;
346  st->codec->channel_layout = AV_CH_LAYOUT_STEREO;
347  st->codec->sample_rate = samplerate;
348  st->codec->bit_rate = st->codec->sample_rate * framesize * 8 / 1024;
349 
350  /* fake the ATRAC3 extradata
351  * (wav format, makes stream copy to wav work) */
352  if (ff_alloc_extradata(st->codec, 14))
353  return AVERROR(ENOMEM);
354 
355  edata = st->codec->extradata;
356  AV_WL16(&edata[0], 1); // always 1
357  AV_WL32(&edata[2], samplerate); // samples rate
358  AV_WL16(&edata[6], jsflag); // coding mode
359  AV_WL16(&edata[8], jsflag); // coding mode
360  AV_WL16(&edata[10], 1); // always 1
361  // AV_WL16(&edata[12], 0); // always 0
362 
363  avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
364  break;
365  case OMA_CODECID_ATRAC3P:
366  channel_id = (codec_params >> 10) & 7;
367  if (!channel_id) {
368  av_log(s, AV_LOG_ERROR,
369  "Invalid ATRAC-X channel id: %d\n", channel_id);
370  return AVERROR_INVALIDDATA;
371  }
372  st->codec->channel_layout = ff_oma_chid_to_native_layout[channel_id - 1];
373  st->codec->channels = ff_oma_chid_to_num_channels[channel_id - 1];
374  framesize = ((codec_params & 0x3FF) * 8) + 8;
375  samplerate = ff_oma_srate_tab[(codec_params >> 13) & 7] * 100;
376  if (!samplerate) {
377  av_log(s, AV_LOG_ERROR, "Unsupported sample rate\n");
378  return AVERROR_INVALIDDATA;
379  }
380  st->codec->sample_rate = samplerate;
381  st->codec->bit_rate = samplerate * framesize * 8 / 2048;
382  avpriv_set_pts_info(st, 64, 1, samplerate);
383  av_log(s, AV_LOG_ERROR, "Unsupported codec ATRAC3+!\n");
384  break;
385  case OMA_CODECID_MP3:
386  st->need_parsing = AVSTREAM_PARSE_FULL_RAW;
387  framesize = 1024;
388  break;
389  case OMA_CODECID_LPCM:
390  /* PCM 44.1 kHz 16 bit stereo big-endian */
391  st->codec->channels = 2;
392  st->codec->channel_layout = AV_CH_LAYOUT_STEREO;
393  st->codec->sample_rate = 44100;
394  framesize = 1024;
395  /* bit rate = sample rate x PCM block align (= 4) x 8 */
396  st->codec->bit_rate = st->codec->sample_rate * 32;
397  st->codec->bits_per_coded_sample =
398  av_get_bits_per_sample(st->codec->codec_id);
399  avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
400  break;
401  default:
402  av_log(s, AV_LOG_ERROR, "Unsupported codec %d!\n", buf[32]);
403  return AVERROR(ENOSYS);
404  }
405 
406  st->codec->block_align = framesize;
407 
408  return 0;
409 }
410 
411 
412  static int oma_read_packet(AVFormatContext *s, AVPacket *pkt)
413 {
414  OMAContext *oc = s->priv_data;
415  int packet_size = s->streams[0]->codec->block_align;
416  int ret = av_get_packet(s->pb, pkt, packet_size);
417 
418  if (ret < packet_size)
419  pkt->flags |= AV_PKT_FLAG_CORRUPT;
420 
421  if (ret < 0)
422  return ret;
423  if (!ret)
424  return AVERROR_EOF;
425 
426  pkt->stream_index = 0;
427 
428  if (oc->encrypted) {
429  /* previous unencrypted block saved in IV for
430  * the next packet (CBC mode) */
431  if (ret == packet_size)
432  av_des_crypt(&oc->av_des, pkt->data, pkt->data,
433  (packet_size >> 3), oc->iv, 1);
434  else
435  memset(oc->iv, 0, 8);
436  }
437 
438  return ret;
439 }
440 
441  static int oma_read_probe(AVProbeData *p)
442 {
443  const uint8_t *buf;
444  unsigned tag_len = 0;
445 
446  buf = p->buf;
447 
448  if (p->buf_size < ID3v2_HEADER_SIZE ||
449  !ff_id3v2_match(buf, ID3v2_EA3_MAGIC) ||
450  buf[3] != 3 || // version must be 3
451  buf[4]) // flags byte zero
452  return 0;
453 
454  tag_len = ff_id3v2_tag_len(buf);
455 
456  /* This check cannot overflow as tag_len has at most 28 bits */
457  if (p->buf_size < tag_len + 5)
458  /* EA3 header comes late, might be outside of the probe buffer */
459  return AVPROBE_SCORE_EXTENSION;
460 
461  buf += tag_len;
462 
463  if (!memcmp(buf, "EA3", 3) && !buf[4] && buf[5] == EA3_HEADER_SIZE)
464  return AVPROBE_SCORE_MAX;
465  else
466  return 0;
467 }
468 
469  static int oma_read_seek(struct AVFormatContext *s,
470  int stream_index, int64_t timestamp, int flags)
471 {
472  OMAContext *oc = s->priv_data;
473  int err = ff_pcm_read_seek(s, stream_index, timestamp, flags);
474 
475  if (!oc->encrypted)
476  return err;
477 
478  /* readjust IV for CBC */
479  if (err || avio_tell(s->pb) < oc->content_start)
480  goto wipe;
481  if ((err = avio_seek(s->pb, -8, SEEK_CUR)) < 0)
482  goto wipe;
483  if ((err = avio_read(s->pb, oc->iv, 8)) < 8) {
484  if (err >= 0)
485  err = AVERROR_EOF;
486  goto wipe;
487  }
488 
489  return 0;
490 wipe:
491  memset(oc->iv, 0, 8);
492  return err;
493 }
494 
495  AVInputFormat ff_oma_demuxer = {
496  .name = "oma",
497  .long_name = NULL_IF_CONFIG_SMALL("Sony OpenMG audio"),
498  .priv_data_size = sizeof(OMAContext),
499  .read_probe = oma_read_probe,
500  .read_header = oma_read_header,
501  .read_packet = oma_read_packet,
502  .read_seek = oma_read_seek,
503  .flags = AVFMT_GENERIC_INDEX,
504  .extensions = "oma,omg,aa3",
505  .codec_tag = (const AVCodecTag* const []){ff_oma_codec_tags, 0},
506 };
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