Libav
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 Libav.
9  *
10  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23  */
24 
44 #include "avformat.h"
45 #include "internal.h"
46 #include "libavutil/intreadwrite.h"
47 #include "libavutil/des.h"
48 #include "oma.h"
49 #include "pcm.h"
50 #include "id3v2.h"
51 
52 
53 static const uint64_t leaf_table[] = {
54  0xd79e8283acea4620, 0x7a9762f445afd0d8,
55  0x354d60a60b8c79f1, 0x584e1cde00b07aee,
56  0x1573cd93da7df623, 0x47f98d79620dd535
57 };
58 
59 typedef struct OMAContext {
60  uint64_t content_start;
61  int encrypted;
62  uint16_t k_size;
63  uint16_t e_size;
64  uint16_t i_size;
65  uint16_t s_size;
66  uint32_t rid;
73  uint8_t iv[8];
74  struct AVDES av_des;
75 } OMAContext;
76 
77 static void hex_log(AVFormatContext *s, int level,
78  const char *name, const uint8_t *value, int len)
79 {
80  char buf[33];
81  len = FFMIN(len, 16);
82  if (av_log_get_level() < level)
83  return;
84  ff_data_to_hex(buf, value, len, 1);
85  buf[len << 1] = '\0';
86  av_log(s, level, "%s: %s\n", name, buf);
87 }
88 
89 static int kset(AVFormatContext *s, const uint8_t *r_val, const uint8_t *n_val,
90  int len)
91 {
92  OMAContext *oc = s->priv_data;
93 
94  if (!r_val && !n_val)
95  return -1;
96 
97  len = FFMIN(len, 16);
98 
99  /* use first 64 bits in the third round again */
100  if (r_val) {
101  if (r_val != oc->r_val) {
102  memset(oc->r_val, 0, 24);
103  memcpy(oc->r_val, r_val, len);
104  }
105  memcpy(&oc->r_val[16], r_val, 8);
106  }
107  if (n_val) {
108  if (n_val != oc->n_val) {
109  memset(oc->n_val, 0, 24);
110  memcpy(oc->n_val, n_val, len);
111  }
112  memcpy(&oc->n_val[16], n_val, 8);
113  }
114 
115  return 0;
116 }
117 
118 #define OMA_RPROBE_M_VAL 48 + 1
119 
120 static int rprobe(AVFormatContext *s, uint8_t *enc_header, unsigned size,
121  const uint8_t *r_val)
122 {
123  OMAContext *oc = s->priv_data;
124  unsigned int pos;
125  struct AVDES av_des;
126 
127  if (!enc_header || !r_val ||
128  size < OMA_ENC_HEADER_SIZE + oc->k_size + oc->e_size + oc->i_size ||
129  size < OMA_RPROBE_M_VAL)
130  return -1;
131 
132  /* m_val */
133  av_des_init(&av_des, r_val, 192, 1);
134  av_des_crypt(&av_des, oc->m_val, &enc_header[48], 1, NULL, 1);
135 
136  /* s_val */
137  av_des_init(&av_des, oc->m_val, 64, 0);
138  av_des_crypt(&av_des, oc->s_val, NULL, 1, NULL, 0);
139 
140  /* sm_val */
141  pos = OMA_ENC_HEADER_SIZE + oc->k_size + oc->e_size;
142  av_des_init(&av_des, oc->s_val, 64, 0);
143  av_des_mac(&av_des, oc->sm_val, &enc_header[pos], (oc->i_size >> 3));
144 
145  pos += oc->i_size;
146 
147  return memcmp(&enc_header[pos], oc->sm_val, 8) ? -1 : 0;
148 }
149 
150 static int nprobe(AVFormatContext *s, uint8_t *enc_header, unsigned size,
151  const uint8_t *n_val)
152 {
153  OMAContext *oc = s->priv_data;
154  uint64_t pos;
155  uint32_t taglen, datalen;
156  struct AVDES av_des;
157 
158  if (!enc_header || !n_val ||
159  size < OMA_ENC_HEADER_SIZE + oc->k_size + 4)
160  return -1;
161 
162  pos = OMA_ENC_HEADER_SIZE + oc->k_size;
163  if (!memcmp(&enc_header[pos], "EKB ", 4))
164  pos += 32;
165 
166  if (size < pos + 44)
167  return -1;
168 
169  if (AV_RB32(&enc_header[pos]) != oc->rid)
170  av_log(s, AV_LOG_DEBUG, "Mismatching RID\n");
171 
172  taglen = AV_RB32(&enc_header[pos + 32]);
173  datalen = AV_RB32(&enc_header[pos + 36]) >> 4;
174 
175  pos += 44;
176  if (size - pos < taglen)
177  return -1;
178 
179  pos += taglen;
180 
181  if (datalen << 4 > size - pos)
182  return -1;
183 
184  av_des_init(&av_des, n_val, 192, 1);
185  while (datalen-- > 0) {
186  av_des_crypt(&av_des, oc->r_val, &enc_header[pos], 2, NULL, 1);
187  kset(s, oc->r_val, NULL, 16);
188  if (!rprobe(s, enc_header, size, oc->r_val))
189  return 0;
190  pos += 16;
191  }
192 
193  return -1;
194 }
195 
197 {
198  OMAContext *oc = s->priv_data;
199  ID3v2ExtraMetaGEOB *geob = NULL;
200  uint8_t *gdata;
201 
202  oc->encrypted = 1;
203  av_log(s, AV_LOG_INFO, "File is encrypted\n");
204 
205  /* find GEOB metadata */
206  while (em) {
207  if (!strcmp(em->tag, "GEOB") &&
208  (geob = em->data) &&
209  (!strcmp(geob->description, "OMG_LSI") ||
210  !strcmp(geob->description, "OMG_BKLSI"))) {
211  break;
212  }
213  em = em->next;
214  }
215  if (!em) {
216  av_log(s, AV_LOG_ERROR, "No encryption header found\n");
217  return AVERROR_INVALIDDATA;
218  }
219 
220  if (geob->datasize < 64) {
221  av_log(s, AV_LOG_ERROR,
222  "Invalid GEOB data size: %u\n", geob->datasize);
223  return AVERROR_INVALIDDATA;
224  }
225 
226  gdata = geob->data;
227 
228  if (AV_RB16(gdata) != 1)
229  av_log(s, AV_LOG_WARNING, "Unknown version in encryption header\n");
230 
231  oc->k_size = AV_RB16(&gdata[2]);
232  oc->e_size = AV_RB16(&gdata[4]);
233  oc->i_size = AV_RB16(&gdata[6]);
234  oc->s_size = AV_RB16(&gdata[8]);
235 
236  if (memcmp(&gdata[OMA_ENC_HEADER_SIZE], "KEYRING ", 12)) {
237  av_log(s, AV_LOG_ERROR, "Invalid encryption header\n");
238  return AVERROR_INVALIDDATA;
239  }
240  if (OMA_ENC_HEADER_SIZE + oc->k_size + oc->e_size + oc->i_size + 8 > geob->datasize ||
241  OMA_ENC_HEADER_SIZE + 48 > geob->datasize) {
242  av_log(s, AV_LOG_ERROR, "Too little GEOB data\n");
243  return AVERROR_INVALIDDATA;
244  }
245  oc->rid = AV_RB32(&gdata[OMA_ENC_HEADER_SIZE + 28]);
246  av_log(s, AV_LOG_DEBUG, "RID: %.8x\n", oc->rid);
247 
248  memcpy(oc->iv, &header[0x58], 8);
249  hex_log(s, AV_LOG_DEBUG, "IV", oc->iv, 8);
250 
251  hex_log(s, AV_LOG_DEBUG, "CBC-MAC",
252  &gdata[OMA_ENC_HEADER_SIZE + oc->k_size + oc->e_size + oc->i_size],
253  8);
254 
255  if (s->keylen > 0) {
256  kset(s, s->key, s->key, s->keylen);
257  }
258  if (!memcmp(oc->r_val, (const uint8_t[8]){0}, 8) ||
259  rprobe(s, gdata, geob->datasize, oc->r_val) < 0 &&
260  nprobe(s, gdata, geob->datasize, oc->n_val) < 0) {
261  int i;
262  for (i = 0; i < FF_ARRAY_ELEMS(leaf_table); i += 2) {
263  uint8_t buf[16];
264  AV_WL64(buf, leaf_table[i]);
265  AV_WL64(&buf[8], leaf_table[i + 1]);
266  kset(s, buf, buf, 16);
267  if (!rprobe(s, gdata, geob->datasize, oc->r_val) ||
268  !nprobe(s, gdata, geob->datasize, oc->n_val))
269  break;
270  }
271  if (i >= FF_ARRAY_ELEMS(leaf_table)) {
272  av_log(s, AV_LOG_ERROR, "Invalid key\n");
273  return AVERROR_INVALIDDATA;
274  }
275  }
276 
277  /* e_val */
278  av_des_init(&oc->av_des, oc->m_val, 64, 0);
279  av_des_crypt(&oc->av_des, oc->e_val,
280  &gdata[OMA_ENC_HEADER_SIZE + 40], 1, NULL, 0);
281  hex_log(s, AV_LOG_DEBUG, "EK", oc->e_val, 8);
282 
283  /* init e_val */
284  av_des_init(&oc->av_des, oc->e_val, 64, 1);
285 
286  return 0;
287 }
288 
290 {
291  int ret, framesize, jsflag, samplerate;
292  uint32_t codec_params, channel_id;
293  int16_t eid;
295  uint8_t *edata;
296  AVStream *st;
297  ID3v2ExtraMeta *extra_meta = NULL;
298  OMAContext *oc = s->priv_data;
299 
300  ff_id3v2_read(s, ID3v2_EA3_MAGIC, &extra_meta);
301  ret = avio_read(s->pb, buf, EA3_HEADER_SIZE);
302  if (ret < EA3_HEADER_SIZE)
303  return -1;
304 
305  if (memcmp(buf, ((const uint8_t[]){'E', 'A', '3'}), 3) ||
306  buf[4] != 0 || buf[5] != EA3_HEADER_SIZE) {
307  av_log(s, AV_LOG_ERROR, "Couldn't find the EA3 header !\n");
308  return AVERROR_INVALIDDATA;
309  }
310 
311  oc->content_start = avio_tell(s->pb);
312 
313  /* encrypted file */
314  eid = AV_RB16(&buf[6]);
315  if (eid != -1 && eid != -128 && decrypt_init(s, extra_meta, buf) < 0) {
316  ff_id3v2_free_extra_meta(&extra_meta);
317  return -1;
318  }
319 
320  ff_id3v2_free_extra_meta(&extra_meta);
321 
322  codec_params = AV_RB24(&buf[33]);
323 
324  st = avformat_new_stream(s, NULL);
325  if (!st)
326  return AVERROR(ENOMEM);
327 
328  st->start_time = 0;
330  st->codec->codec_tag = buf[32];
332  st->codec->codec_tag);
333 
334  switch (buf[32]) {
335  case OMA_CODECID_ATRAC3:
336  samplerate = ff_oma_srate_tab[(codec_params >> 13) & 7] * 100;
337  if (!samplerate) {
338  av_log(s, AV_LOG_ERROR, "Unsupported sample rate\n");
339  return AVERROR_INVALIDDATA;
340  }
341  if (samplerate != 44100)
342  avpriv_request_sample(s, "Sample rate %d", samplerate);
343 
344  framesize = (codec_params & 0x3FF) * 8;
345 
346  /* get stereo coding mode, 1 for joint-stereo */
347  jsflag = (codec_params >> 17) & 1;
348 
349  st->codec->channels = 2;
351  st->codec->sample_rate = samplerate;
352  st->codec->bit_rate = st->codec->sample_rate * framesize * 8 / 1024;
353 
354  /* fake the ATRAC3 extradata
355  * (wav format, makes stream copy to wav work) */
356  st->codec->extradata_size = 14;
358  if (!edata)
359  return AVERROR(ENOMEM);
360 
361  st->codec->extradata = edata;
362  AV_WL16(&edata[0], 1); // always 1
363  AV_WL32(&edata[2], samplerate); // samples rate
364  AV_WL16(&edata[6], jsflag); // coding mode
365  AV_WL16(&edata[8], jsflag); // coding mode
366  AV_WL16(&edata[10], 1); // always 1
367  // AV_WL16(&edata[12], 0); // always 0
368 
369  avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
370  break;
371  case OMA_CODECID_ATRAC3P:
372  channel_id = (codec_params >> 10) & 7;
373  if (!channel_id) {
374  av_log(s, AV_LOG_ERROR,
375  "Invalid ATRAC-X channel id: %d\n", channel_id);
376  return AVERROR_INVALIDDATA;
377  }
378  st->codec->channel_layout = ff_oma_chid_to_native_layout[channel_id - 1];
379  st->codec->channels = ff_oma_chid_to_num_channels[channel_id - 1];
380  framesize = ((codec_params & 0x3FF) * 8) + 8;
381  samplerate = ff_oma_srate_tab[(codec_params >> 13) & 7] * 100;
382  if (!samplerate) {
383  av_log(s, AV_LOG_ERROR, "Unsupported sample rate\n");
384  return AVERROR_INVALIDDATA;
385  }
386  st->codec->sample_rate = samplerate;
387  st->codec->bit_rate = samplerate * framesize * 8 / 2048;
388  avpriv_set_pts_info(st, 64, 1, samplerate);
389  break;
390  case OMA_CODECID_MP3:
392  framesize = 1024;
393  break;
394  case OMA_CODECID_LPCM:
395  /* PCM 44.1 kHz 16 bit stereo big-endian */
396  st->codec->channels = 2;
398  st->codec->sample_rate = 44100;
399  framesize = 1024;
400  /* bit rate = sample rate x PCM block align (= 4) x 8 */
401  st->codec->bit_rate = st->codec->sample_rate * 32;
404  avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
405  break;
406  default:
407  av_log(s, AV_LOG_ERROR, "Unsupported codec %d!\n", buf[32]);
408  return AVERROR(ENOSYS);
409  }
410 
411  st->codec->block_align = framesize;
412 
413  return 0;
414 }
415 
416 
418 {
419  OMAContext *oc = s->priv_data;
420  int packet_size = s->streams[0]->codec->block_align;
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 (oc->encrypted) {
434  /* previous unencrypted block saved in IV for
435  * the next packet (CBC mode) */
436  if (ret == packet_size)
437  av_des_crypt(&oc->av_des, pkt->data, pkt->data,
438  (packet_size >> 3), oc->iv, 1);
439  else
440  memset(oc->iv, 0, 8);
441  }
442 
443  return ret;
444 }
445 
447 {
448  const uint8_t *buf = p->buf;
449  unsigned tag_len = 0;
450 
452  tag_len = ff_id3v2_tag_len(buf);
453 
454  /* This check cannot overflow as tag_len has at most 28 bits */
455  if (p->buf_size < tag_len + 5)
456  /* EA3 header comes late, might be outside of the probe buffer */
457  return tag_len ? AVPROBE_SCORE_EXTENSION : 0;
458 
459  buf += tag_len;
460 
461  if (!memcmp(buf, "EA3", 3) && !buf[4] && buf[5] == EA3_HEADER_SIZE)
462  return AVPROBE_SCORE_MAX;
463  else
464  return 0;
465 }
466 
467 static int oma_read_seek(struct AVFormatContext *s,
468  int stream_index, int64_t timestamp, int flags)
469 {
470  OMAContext *oc = s->priv_data;
471  int err = ff_pcm_read_seek(s, stream_index, timestamp, flags);
472 
473  if (!oc->encrypted)
474  return err;
475 
476  /* readjust IV for CBC */
477  if (err || avio_tell(s->pb) < oc->content_start)
478  goto wipe;
479  if ((err = avio_seek(s->pb, -8, SEEK_CUR)) < 0)
480  goto wipe;
481  if ((err = avio_read(s->pb, oc->iv, 8)) < 8) {
482  if (err >= 0)
483  err = AVERROR_EOF;
484  goto wipe;
485  }
486 
487  return 0;
488 wipe:
489  memset(oc->iv, 0, 8);
490  return err;
491 }
492 
494  .name = "oma",
495  .long_name = NULL_IF_CONFIG_SMALL("Sony OpenMG audio"),
496  .priv_data_size = sizeof(OMAContext),
502  .extensions = "oma,omg,aa3",
503  .codec_tag = (const AVCodecTag* const []){ff_oma_codec_tags, 0},
504 };