omadec.c
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1 /*
2  * Sony OpenMG (OMA) demuxer
3  *
4  * Copyright (c) 2008 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 
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 "riff.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;
67  uint8_t r_val[24];
68  uint8_t n_val[24];
69  uint8_t m_val[8];
70  uint8_t s_val[8];
71  uint8_t sm_val[8];
72  uint8_t e_val[8];
73  uint8_t iv[8];
74  struct AVDES av_des;
75 } OMAContext;
76 
77 static void hex_log(AVFormatContext *s, int level, 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';
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, int len)
89 {
90  OMAContext *oc = s->priv_data;
91 
92  if (!r_val && !n_val)
93  return -1;
94 
95  len = FFMIN(len, 16);
96 
97  /* use first 64 bits in the third round again */
98  if (r_val) {
99  if (r_val != oc->r_val) {
100  memset(oc->r_val, 0, 24);
101  memcpy(oc->r_val, r_val, len);
102  }
103  memcpy(&oc->r_val[16], r_val, 8);
104  }
105  if (n_val) {
106  if (n_val != oc->n_val) {
107  memset(oc->n_val, 0, 24);
108  memcpy(oc->n_val, n_val, len);
109  }
110  memcpy(&oc->n_val[16], n_val, 8);
111  }
112 
113  return 0;
114 }
115 
116 #define OMA_RPROBE_M_VAL 48 + 1
117 
118 static int rprobe(AVFormatContext *s, uint8_t *enc_header, unsigned size,
119  const uint8_t *r_val)
120 {
121  OMAContext *oc = s->priv_data;
122  unsigned int pos;
123  struct AVDES av_des;
124 
125  if (!enc_header || !r_val ||
126  size < OMA_ENC_HEADER_SIZE + oc->k_size + oc->e_size + oc->i_size ||
127  size < OMA_RPROBE_M_VAL)
128  return -1;
129 
130  /* m_val */
131  av_des_init(&av_des, r_val, 192, 1);
132  av_des_crypt(&av_des, oc->m_val, &enc_header[48], 1, NULL, 1);
133 
134  /* s_val */
135  av_des_init(&av_des, oc->m_val, 64, 0);
136  av_des_crypt(&av_des, oc->s_val, NULL, 1, NULL, 0);
137 
138  /* sm_val */
139  pos = OMA_ENC_HEADER_SIZE + oc->k_size + oc->e_size;
140  av_des_init(&av_des, oc->s_val, 64, 0);
141  av_des_mac(&av_des, oc->sm_val, &enc_header[pos], (oc->i_size >> 3));
142 
143  pos += oc->i_size;
144 
145  return memcmp(&enc_header[pos], oc->sm_val, 8) ? -1 : 0;
146 }
147 
148 static int nprobe(AVFormatContext *s, uint8_t *enc_header, unsigned size,
149  const uint8_t *n_val)
150 {
151  OMAContext *oc = s->priv_data;
152  uint64_t pos;
153  uint32_t taglen, datalen;
154  struct AVDES av_des;
155 
156  if (!enc_header || !n_val ||
157  size < OMA_ENC_HEADER_SIZE + oc->k_size + 4)
158  return -1;
159 
160  pos = OMA_ENC_HEADER_SIZE + oc->k_size;
161  if (!memcmp(&enc_header[pos], "EKB ", 4))
162  pos += 32;
163 
164  if (size < pos + 44)
165  return -1;
166 
167  if (AV_RB32(&enc_header[pos]) != oc->rid)
168  av_log(s, AV_LOG_DEBUG, "Mismatching RID\n");
169 
170  taglen = AV_RB32(&enc_header[pos+32]);
171  datalen = AV_RB32(&enc_header[pos+36]) >> 4;
172 
173  pos += 44 + taglen;
174 
175  if (datalen << 4 > size - pos)
176  return -1;
177 
178  av_des_init(&av_des, n_val, 192, 1);
179  while (datalen-- > 0) {
180  av_des_crypt(&av_des, oc->r_val, &enc_header[pos], 2, NULL, 1);
181  kset(s, oc->r_val, NULL, 16);
182  if (!rprobe(s, enc_header, size, oc->r_val))
183  return 0;
184  pos += 16;
185  }
186 
187  return -1;
188 }
189 
190 static int decrypt_init(AVFormatContext *s, ID3v2ExtraMeta *em, uint8_t *header)
191 {
192  OMAContext *oc = s->priv_data;
193  ID3v2ExtraMetaGEOB *geob = NULL;
194  uint8_t *gdata;
195 
196  oc->encrypted = 1;
197  av_log(s, AV_LOG_INFO, "File is encrypted\n");
198 
199  /* find GEOB metadata */
200  while (em) {
201  if (!strcmp(em->tag, "GEOB") &&
202  (geob = em->data) &&
203  (!strcmp(geob->description, "OMG_LSI") ||
204  !strcmp(geob->description, "OMG_BKLSI"))) {
205  break;
206  }
207  em = em->next;
208  }
209  if (!em) {
210  av_log(s, AV_LOG_ERROR, "No encryption header found\n");
211  return -1;
212  }
213 
214  if (geob->datasize < 64) {
215  av_log(s, AV_LOG_ERROR, "Invalid GEOB data size: %u\n", geob->datasize);
216  return -1;
217  }
218 
219  gdata = geob->data;
220 
221  if (AV_RB16(gdata) != 1)
222  av_log(s, AV_LOG_WARNING, "Unknown version in encryption header\n");
223 
224  oc->k_size = AV_RB16(&gdata[2]);
225  oc->e_size = AV_RB16(&gdata[4]);
226  oc->i_size = AV_RB16(&gdata[6]);
227  oc->s_size = AV_RB16(&gdata[8]);
228 
229  if (memcmp(&gdata[OMA_ENC_HEADER_SIZE], "KEYRING ", 12)) {
230  av_log(s, AV_LOG_ERROR, "Invalid encryption header\n");
231  return -1;
232  }
233  oc->rid = AV_RB32(&gdata[OMA_ENC_HEADER_SIZE + 28]);
234  av_log(s, AV_LOG_DEBUG, "RID: %.8x\n", oc->rid);
235 
236  memcpy(oc->iv, &header[0x58], 8);
237  hex_log(s, AV_LOG_DEBUG, "IV", oc->iv, 8);
238 
239  hex_log(s, AV_LOG_DEBUG, "CBC-MAC", &gdata[OMA_ENC_HEADER_SIZE+oc->k_size+oc->e_size+oc->i_size], 8);
240 
241  if (s->keylen > 0) {
242  kset(s, s->key, s->key, s->keylen);
243  }
244  if (!memcmp(oc->r_val, (const uint8_t[8]){0}, 8) ||
245  rprobe(s, gdata, geob->datasize, oc->r_val) < 0 &&
246  nprobe(s, gdata, geob->datasize, oc->n_val) < 0) {
247  int i;
248  for (i = 0; i < FF_ARRAY_ELEMS(leaf_table); i += 2) {
249  uint8_t buf[16];
250  AV_WL64(buf, leaf_table[i]);
251  AV_WL64(&buf[8], leaf_table[i+1]);
252  kset(s, buf, buf, 16);
253  if (!rprobe(s, gdata, geob->datasize, oc->r_val) ||
254  !nprobe(s, gdata, geob->datasize, oc->n_val))
255  break;
256  }
257  if (i >= sizeof(leaf_table)) {
258  av_log(s, AV_LOG_ERROR, "Invalid key\n");
259  return -1;
260  }
261  }
262 
263  /* e_val */
264  av_des_init(&oc->av_des, oc->m_val, 64, 0);
265  av_des_crypt(&oc->av_des, oc->e_val, &gdata[OMA_ENC_HEADER_SIZE + 40], 1, NULL, 0);
266  hex_log(s, AV_LOG_DEBUG, "EK", oc->e_val, 8);
267 
268  /* init e_val */
269  av_des_init(&oc->av_des, oc->e_val, 64, 1);
270 
271  return 0;
272 }
273 
275  AVFormatParameters *ap)
276 {
277  int ret, framesize, jsflag, samplerate;
278  uint32_t codec_params;
279  int16_t eid;
280  uint8_t buf[EA3_HEADER_SIZE];
281  uint8_t *edata;
282  AVStream *st;
283  ID3v2ExtraMeta *extra_meta = NULL;
284  OMAContext *oc = s->priv_data;
285 
286  ff_id3v2_read_all(s, ID3v2_EA3_MAGIC, &extra_meta);
287  ret = avio_read(s->pb, buf, EA3_HEADER_SIZE);
288  if (ret < EA3_HEADER_SIZE)
289  return -1;
290 
291  if (memcmp(buf, ((const uint8_t[]){'E', 'A', '3'}),3) || buf[4] != 0 || buf[5] != EA3_HEADER_SIZE) {
292  av_log(s, AV_LOG_ERROR, "Couldn't find the EA3 header !\n");
293  return -1;
294  }
295 
296  oc->content_start = avio_tell(s->pb);
297 
298  /* encrypted file */
299  eid = AV_RB16(&buf[6]);
300  if (eid != -1 && eid != -128 && decrypt_init(s, extra_meta, buf) < 0) {
301  ff_id3v2_free_extra_meta(&extra_meta);
302  return -1;
303  }
304 
305  ff_id3v2_free_extra_meta(&extra_meta);
306 
307  codec_params = AV_RB24(&buf[33]);
308 
309  st = avformat_new_stream(s, NULL);
310  if (!st)
311  return AVERROR(ENOMEM);
312 
313  st->start_time = 0;
315  st->codec->codec_tag = buf[32];
317 
318  switch (buf[32]) {
319  case OMA_CODECID_ATRAC3:
320  samplerate = ff_oma_srate_tab[(codec_params >> 13) & 7] * 100;
321  if (!samplerate) {
322  av_log(s, AV_LOG_ERROR, "Unsupported sample rate\n");
323  return AVERROR_INVALIDDATA;
324  }
325  if (samplerate != 44100)
326  av_log_ask_for_sample(s, "Unsupported sample rate: %d\n",
327  samplerate);
328 
329  framesize = (codec_params & 0x3FF) * 8;
330  jsflag = (codec_params >> 17) & 1; /* get stereo coding mode, 1 for joint-stereo */
331  st->codec->channels = 2;
332  st->codec->sample_rate = samplerate;
333  st->codec->bit_rate = st->codec->sample_rate * framesize * 8 / 1024;
334 
335  /* fake the atrac3 extradata (wav format, makes stream copy to wav work) */
336  st->codec->extradata_size = 14;
338  if (!edata)
339  return AVERROR(ENOMEM);
340 
341  st->codec->extradata = edata;
342  AV_WL16(&edata[0], 1); // always 1
343  AV_WL32(&edata[2], samplerate); // samples rate
344  AV_WL16(&edata[6], jsflag); // coding mode
345  AV_WL16(&edata[8], jsflag); // coding mode
346  AV_WL16(&edata[10], 1); // always 1
347  // AV_WL16(&edata[12], 0); // always 0
348 
349  avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
350  break;
351  case OMA_CODECID_ATRAC3P:
352  st->codec->channels = (codec_params >> 10) & 7;
353  framesize = ((codec_params & 0x3FF) * 8) + 8;
354  samplerate = ff_oma_srate_tab[(codec_params >> 13) & 7] * 100;
355  if (!samplerate) {
356  av_log(s, AV_LOG_ERROR, "Unsupported sample rate\n");
357  return AVERROR_INVALIDDATA;
358  }
359  st->codec->sample_rate = samplerate;
360  st->codec->bit_rate = samplerate * framesize * 8 / 1024;
361  avpriv_set_pts_info(st, 64, 1, samplerate);
362  av_log(s, AV_LOG_ERROR, "Unsupported codec ATRAC3+!\n");
363  break;
364  case OMA_CODECID_MP3:
366  framesize = 1024;
367  break;
368  case OMA_CODECID_LPCM:
369  /* PCM 44.1 kHz 16 bit stereo big-endian */
370  st->codec->channels = 2;
371  st->codec->sample_rate = 44100;
372  framesize = 1024;
373  /* bit rate = sample rate x PCM block align (= 4) x 8 */
374  st->codec->bit_rate = st->codec->sample_rate * 32;
376  avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
377  break;
378  default:
379  av_log(s, AV_LOG_ERROR, "Unsupported codec %d!\n",buf[32]);
380  return -1;
381  }
382 
383  st->codec->block_align = framesize;
384 
385  return 0;
386 }
387 
388 
390 {
391  OMAContext *oc = s->priv_data;
392  int packet_size = s->streams[0]->codec->block_align;
393  int ret = av_get_packet(s->pb, pkt, packet_size);
394 
395  if (ret < packet_size)
396  pkt->flags |= AV_PKT_FLAG_CORRUPT;
397 
398  if (ret <= 0)
399  return AVERROR(EIO);
400 
401  pkt->stream_index = 0;
402 
403  if (oc->encrypted) {
404  /* previous unencrypted block saved in IV for
405  * the next packet (CBC mode) */
406  if (ret == packet_size)
407  av_des_crypt(&oc->av_des, pkt->data, pkt->data,
408  (packet_size >> 3), oc->iv, 1);
409  else
410  memset(oc->iv, 0, 8);
411  }
412 
413  return ret;
414 }
415 
417 {
418  const uint8_t *buf;
419  unsigned tag_len = 0;
420 
421  buf = p->buf;
422 
423  if (p->buf_size < ID3v2_HEADER_SIZE ||
425  buf[3] != 3 || // version must be 3
426  buf[4]) // flags byte zero
427  return 0;
428 
429  tag_len = ff_id3v2_tag_len(buf);
430 
431  /* This check cannot overflow as tag_len has at most 28 bits */
432  if (p->buf_size < tag_len + 5)
433  /* EA3 header comes late, might be outside of the probe buffer */
434  return AVPROBE_SCORE_MAX / 2;
435 
436  buf += tag_len;
437 
438  if (!memcmp(buf, "EA3", 3) && !buf[4] && buf[5] == EA3_HEADER_SIZE)
439  return AVPROBE_SCORE_MAX;
440  else
441  return 0;
442 }
443 
444 static int oma_read_seek(struct AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
445 {
446  OMAContext *oc = s->priv_data;
447 
448  int err = pcm_read_seek(s, stream_index, timestamp, flags);
449 
450  if (!oc->encrypted)
451  return err;
452 
453  /* readjust IV for CBC */
454  if (err || avio_tell(s->pb) < oc->content_start)
455  goto wipe;
456  if ((err = avio_seek(s->pb, -8, SEEK_CUR)) < 0)
457  goto wipe;
458  if ((err = avio_read(s->pb, oc->iv, 8)) < 8) {
459  if (err >= 0)
460  err = AVERROR_EOF;
461  goto wipe;
462  }
463 
464  return 0;
465 wipe:
466  memset(oc->iv, 0, 8);
467  return err;
468 }
469 
471  .name = "oma",
472  .long_name = NULL_IF_CONFIG_SMALL("Sony OpenMG audio"),
473  .priv_data_size = sizeof(OMAContext),
479  .extensions = "oma,omg,aa3",
480  .codec_tag = (const AVCodecTag* const []){ff_oma_codec_tags, 0},
481 };
482