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 static int rprobe(AVFormatContext *s, uint8_t *enc_header, const uint8_t *r_val)
117 {
118  OMAContext *oc = s->priv_data;
119  unsigned int pos;
120  struct AVDES av_des;
121 
122  if (!enc_header || !r_val)
123  return -1;
124 
125  /* m_val */
126  av_des_init(&av_des, r_val, 192, 1);
127  av_des_crypt(&av_des, oc->m_val, &enc_header[48], 1, NULL, 1);
128 
129  /* s_val */
130  av_des_init(&av_des, oc->m_val, 64, 0);
131  av_des_crypt(&av_des, oc->s_val, NULL, 1, NULL, 0);
132 
133  /* sm_val */
134  pos = OMA_ENC_HEADER_SIZE + oc->k_size + oc->e_size;
135  av_des_init(&av_des, oc->s_val, 64, 0);
136  av_des_mac(&av_des, oc->sm_val, &enc_header[pos], (oc->i_size >> 3));
137 
138  pos += oc->i_size;
139 
140  return memcmp(&enc_header[pos], oc->sm_val, 8) ? -1 : 0;
141 }
142 
143 static int nprobe(AVFormatContext *s, uint8_t *enc_header, const uint8_t *n_val)
144 {
145  OMAContext *oc = s->priv_data;
146  uint32_t pos, taglen, datalen;
147  struct AVDES av_des;
148 
149  if (!enc_header || !n_val)
150  return -1;
151 
152  pos = OMA_ENC_HEADER_SIZE + oc->k_size;
153  if (!memcmp(&enc_header[pos], "EKB ", 4))
154  pos += 32;
155 
156  if (AV_RB32(&enc_header[pos]) != oc->rid)
157  av_log(s, AV_LOG_DEBUG, "Mismatching RID\n");
158 
159  taglen = AV_RB32(&enc_header[pos+32]);
160  datalen = AV_RB32(&enc_header[pos+36]) >> 4;
161 
162  pos += 44 + taglen;
163 
164  av_des_init(&av_des, n_val, 192, 1);
165  while (datalen-- > 0) {
166  av_des_crypt(&av_des, oc->r_val, &enc_header[pos], 2, NULL, 1);
167  kset(s, oc->r_val, NULL, 16);
168  if (!rprobe(s, enc_header, oc->r_val))
169  return 0;
170  pos += 16;
171  }
172 
173  return -1;
174 }
175 
176 static int decrypt_init(AVFormatContext *s, ID3v2ExtraMeta *em, uint8_t *header)
177 {
178  OMAContext *oc = s->priv_data;
179  ID3v2ExtraMetaGEOB *geob = NULL;
180  uint8_t *gdata;
181 
182  oc->encrypted = 1;
183  av_log(s, AV_LOG_INFO, "File is encrypted\n");
184 
185  /* find GEOB metadata */
186  while (em) {
187  if (!strcmp(em->tag, "GEOB") &&
188  (geob = em->data) &&
189  (!strcmp(geob->description, "OMG_LSI") ||
190  !strcmp(geob->description, "OMG_BKLSI"))) {
191  break;
192  }
193  em = em->next;
194  }
195  if (!em) {
196  av_log(s, AV_LOG_ERROR, "No encryption header found\n");
197  return -1;
198  }
199 
200  if (geob->datasize < 64) {
201  av_log(s, AV_LOG_ERROR, "Invalid GEOB data size: %u\n", geob->datasize);
202  return -1;
203  }
204 
205  gdata = geob->data;
206 
207  if (AV_RB16(gdata) != 1)
208  av_log(s, AV_LOG_WARNING, "Unknown version in encryption header\n");
209 
210  oc->k_size = AV_RB16(&gdata[2]);
211  oc->e_size = AV_RB16(&gdata[4]);
212  oc->i_size = AV_RB16(&gdata[6]);
213  oc->s_size = AV_RB16(&gdata[8]);
214 
215  if (memcmp(&gdata[OMA_ENC_HEADER_SIZE], "KEYRING ", 12)) {
216  av_log(s, AV_LOG_ERROR, "Invalid encryption header\n");
217  return -1;
218  }
219  oc->rid = AV_RB32(&gdata[OMA_ENC_HEADER_SIZE + 28]);
220  av_log(s, AV_LOG_DEBUG, "RID: %.8x\n", oc->rid);
221 
222  memcpy(oc->iv, &header[0x58], 8);
223  hex_log(s, AV_LOG_DEBUG, "IV", oc->iv, 8);
224 
225  hex_log(s, AV_LOG_DEBUG, "CBC-MAC", &gdata[OMA_ENC_HEADER_SIZE+oc->k_size+oc->e_size+oc->i_size], 8);
226 
227  if (s->keylen > 0) {
228  kset(s, s->key, s->key, s->keylen);
229  }
230  if (!memcmp(oc->r_val, (const uint8_t[8]){0}, 8) ||
231  rprobe(s, gdata, oc->r_val) < 0 &&
232  nprobe(s, gdata, oc->n_val) < 0) {
233  int i;
234  for (i = 0; i < FF_ARRAY_ELEMS(leaf_table); i += 2) {
235  uint8_t buf[16];
236  AV_WL64(buf, leaf_table[i]);
237  AV_WL64(&buf[8], leaf_table[i+1]);
238  kset(s, buf, buf, 16);
239  if (!rprobe(s, gdata, oc->r_val) || !nprobe(s, gdata, oc->n_val))
240  break;
241  }
242  if (i >= sizeof(leaf_table)) {
243  av_log(s, AV_LOG_ERROR, "Invalid key\n");
244  return -1;
245  }
246  }
247 
248  /* e_val */
249  av_des_init(&oc->av_des, oc->m_val, 64, 0);
250  av_des_crypt(&oc->av_des, oc->e_val, &gdata[OMA_ENC_HEADER_SIZE + 40], 1, NULL, 0);
251  hex_log(s, AV_LOG_DEBUG, "EK", oc->e_val, 8);
252 
253  /* init e_val */
254  av_des_init(&oc->av_des, oc->e_val, 64, 1);
255 
256  return 0;
257 }
258 
260  AVFormatParameters *ap)
261 {
262  int ret, framesize, jsflag, samplerate;
263  uint32_t codec_params;
264  int16_t eid;
265  uint8_t buf[EA3_HEADER_SIZE];
266  uint8_t *edata;
267  AVStream *st;
268  ID3v2ExtraMeta *extra_meta = NULL;
269  OMAContext *oc = s->priv_data;
270 
271  ff_id3v2_read_all(s, ID3v2_EA3_MAGIC, &extra_meta);
272  ret = avio_read(s->pb, buf, EA3_HEADER_SIZE);
273  if (ret < EA3_HEADER_SIZE)
274  return -1;
275 
276  if (memcmp(buf, ((const uint8_t[]){'E', 'A', '3'}),3) || buf[4] != 0 || buf[5] != EA3_HEADER_SIZE) {
277  av_log(s, AV_LOG_ERROR, "Couldn't find the EA3 header !\n");
278  return -1;
279  }
280 
281  oc->content_start = avio_tell(s->pb);
282 
283  /* encrypted file */
284  eid = AV_RB16(&buf[6]);
285  if (eid != -1 && eid != -128 && decrypt_init(s, extra_meta, buf) < 0) {
286  ff_id3v2_free_extra_meta(&extra_meta);
287  return -1;
288  }
289 
290  ff_id3v2_free_extra_meta(&extra_meta);
291 
292  codec_params = AV_RB24(&buf[33]);
293 
294  st = avformat_new_stream(s, NULL);
295  if (!st)
296  return AVERROR(ENOMEM);
297 
298  st->start_time = 0;
300  st->codec->codec_tag = buf[32];
302 
303  switch (buf[32]) {
304  case OMA_CODECID_ATRAC3:
305  samplerate = ff_oma_srate_tab[(codec_params >> 13) & 7]*100;
306  if (samplerate != 44100)
307  av_log_ask_for_sample(s, "Unsupported sample rate: %d\n",
308  samplerate);
309 
310  framesize = (codec_params & 0x3FF) * 8;
311  jsflag = (codec_params >> 17) & 1; /* get stereo coding mode, 1 for joint-stereo */
312  st->codec->channels = 2;
313  st->codec->sample_rate = samplerate;
314  st->codec->bit_rate = st->codec->sample_rate * framesize * 8 / 1024;
315 
316  /* fake the atrac3 extradata (wav format, makes stream copy to wav work) */
317  st->codec->extradata_size = 14;
319  if (!edata)
320  return AVERROR(ENOMEM);
321 
322  st->codec->extradata = edata;
323  AV_WL16(&edata[0], 1); // always 1
324  AV_WL32(&edata[2], samplerate); // samples rate
325  AV_WL16(&edata[6], jsflag); // coding mode
326  AV_WL16(&edata[8], jsflag); // coding mode
327  AV_WL16(&edata[10], 1); // always 1
328  // AV_WL16(&edata[12], 0); // always 0
329 
330  avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
331  break;
332  case OMA_CODECID_ATRAC3P:
333  st->codec->channels = (codec_params >> 10) & 7;
334  framesize = ((codec_params & 0x3FF) * 8) + 8;
335  st->codec->sample_rate = ff_oma_srate_tab[(codec_params >> 13) & 7]*100;
336  st->codec->bit_rate = st->codec->sample_rate * framesize * 8 / 1024;
337  avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
338  av_log(s, AV_LOG_ERROR, "Unsupported codec ATRAC3+!\n");
339  break;
340  case OMA_CODECID_MP3:
342  framesize = 1024;
343  break;
344  case OMA_CODECID_LPCM:
345  /* PCM 44.1 kHz 16 bit stereo big-endian */
346  st->codec->channels = 2;
347  st->codec->sample_rate = 44100;
348  framesize = 1024;
349  /* bit rate = sample rate x PCM block align (= 4) x 8 */
350  st->codec->bit_rate = st->codec->sample_rate * 32;
352  avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
353  break;
354  default:
355  av_log(s, AV_LOG_ERROR, "Unsupported codec %d!\n",buf[32]);
356  return -1;
357  }
358 
359  st->codec->block_align = framesize;
360 
361  return 0;
362 }
363 
364 
366 {
367  OMAContext *oc = s->priv_data;
368  int packet_size = s->streams[0]->codec->block_align;
369  int ret = av_get_packet(s->pb, pkt, packet_size);
370 
371  if (ret <= 0)
372  return AVERROR(EIO);
373 
374  pkt->stream_index = 0;
375 
376  if (oc->encrypted) {
377  /* previous unencrypted block saved in IV for the next packet (CBC mode) */
378  av_des_crypt(&oc->av_des, pkt->data, pkt->data, (packet_size >> 3), oc->iv, 1);
379  }
380 
381  return ret;
382 }
383 
385 {
386  const uint8_t *buf;
387  unsigned tag_len = 0;
388 
389  buf = p->buf;
390 
391  if (p->buf_size < ID3v2_HEADER_SIZE ||
393  buf[3] != 3 || // version must be 3
394  buf[4]) // flags byte zero
395  return 0;
396 
397  tag_len = ff_id3v2_tag_len(buf);
398 
399  /* This check cannot overflow as tag_len has at most 28 bits */
400  if (p->buf_size < tag_len + 5)
401  /* EA3 header comes late, might be outside of the probe buffer */
402  return AVPROBE_SCORE_MAX / 2;
403 
404  buf += tag_len;
405 
406  if (!memcmp(buf, "EA3", 3) && !buf[4] && buf[5] == EA3_HEADER_SIZE)
407  return AVPROBE_SCORE_MAX;
408  else
409  return 0;
410 }
411 
412 static int oma_read_seek(struct AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
413 {
414  OMAContext *oc = s->priv_data;
415 
416  pcm_read_seek(s, stream_index, timestamp, flags);
417 
418  if (oc->encrypted) {
419  /* readjust IV for CBC */
420  int64_t pos = avio_tell(s->pb);
421  if (pos < oc->content_start)
422  memset(oc->iv, 0, 8);
423  else {
424  if (avio_seek(s->pb, -8, SEEK_CUR) < 0 || avio_read(s->pb, oc->iv, 8) < 8) {
425  memset(oc->iv, 0, 8);
426  return -1;
427  }
428  }
429  }
430 
431  return 0;
432 }
433 
435  .name = "oma",
436  .long_name = NULL_IF_CONFIG_SMALL("Sony OpenMG audio"),
437  .priv_data_size = sizeof(OMAContext),
443  .extensions = "oma,omg,aa3",
444  .codec_tag = (const AVCodecTag* const []){ff_oma_codec_tags, 0},
445 };
446