libavformat/omadec.c

   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
  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
  45 #include "libavutil/channel_layout.h"
  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;
  70     uint8_t r_val[24];
  71     uint8_t n_val[24];
  72     uint8_t m_val[8];
  73     uint8_t s_val[8];
  74     uint8_t sm_val[8];
  75     uint8_t e_val[8];
  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 ||
 162         size < OMA_ENC_HEADER_SIZE + oc->k_size + 4)
 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 += 44;
 179     if (size - pos < taglen)
 180         return -1;
 181
 182     pos += taglen;
 183
 184     if (datalen << 4 > size - pos)
 185         return -1;
 186
 187     av_des_init(&av_des, n_val, 192, 1);
 188     while (datalen-- > 0) {
 189         av_des_crypt(&av_des, oc->r_val, &enc_header[pos], 2, NULL, 1);
 190         kset(s, oc->r_val, NULL, 16);
 191         if (!rprobe(s, enc_header, size, oc->r_val))
 192             return 0;
 193         pos += 16;
 194     }
 195
 196     return -1;
 197 }
 198
 199 static int decrypt_init(AVFormatContext *s, ID3v2ExtraMeta *em, uint8_t *header)
 200 {
 201     OMAContext *oc = s->priv_data;
 202     ID3v2ExtraMetaGEOB *geob = NULL;
 203     uint8_t *gdata;
 204
 205     oc->encrypted = 1;
 206     av_log(s, AV_LOG_INFO, "File is encrypted\n");
 207
 208     /* find GEOB metadata */
 209     while (em) {
 210         if (!strcmp(em->tag, "GEOB") &&
 211             (geob = em->data) &&
 212             (!strcmp(geob->description, "OMG_LSI") ||
 213              !strcmp(geob->description, "OMG_BKLSI"))) {
 214             break;
 215         }
 216         em = em->next;
 217     }
 218     if (!em) {
 219         av_log(s, AV_LOG_ERROR, "No encryption header found\n");
 220         return AVERROR_INVALIDDATA;
 221     }
 222
 223     if (geob->datasize < 64) {
 224         av_log(s, AV_LOG_ERROR,
 225                "Invalid GEOB data size: %"PRIu32"\n", geob->datasize);
 226         return AVERROR_INVALIDDATA;
 227     }
 228
 229     gdata = geob->data;
 230
 231     if (AV_RB16(gdata) != 1)
 232         av_log(s, AV_LOG_WARNING, "Unknown version in encryption header\n");
 233
 234     oc->k_size = AV_RB16(&gdata[2]);
 235     oc->e_size = AV_RB16(&gdata[4]);
 236     oc->i_size = AV_RB16(&gdata[6]);
 237     oc->s_size = AV_RB16(&gdata[8]);
 238
 239     if (memcmp(&gdata[OMA_ENC_HEADER_SIZE], "KEYRING     ", 12)) {
 240         av_log(s, AV_LOG_ERROR, "Invalid encryption header\n");
 241         return AVERROR_INVALIDDATA;
 242     }
 243     if (OMA_ENC_HEADER_SIZE + oc->k_size + oc->e_size + oc->i_size + 8 > geob->datasize ||
 244         OMA_ENC_HEADER_SIZE + 48 > geob->datasize) {
 245         av_log(s, AV_LOG_ERROR, "Too little GEOB data\n");
 246         return AVERROR_INVALIDDATA;
 247     }
 248     oc->rid = AV_RB32(&gdata[OMA_ENC_HEADER_SIZE + 28]);
 249     av_log(s, AV_LOG_DEBUG, "RID: %.8"PRIx32"\n", oc->rid);
 250
 251     memcpy(oc->iv, &header[0x58], 8);
 252     hex_log(s, AV_LOG_DEBUG, "IV", oc->iv, 8);
 253
 254     hex_log(s, AV_LOG_DEBUG, "CBC-MAC",
 255             &gdata[OMA_ENC_HEADER_SIZE + oc->k_size + oc->e_size + oc->i_size],
 256             8);
 257
 258     if (s->keylen > 0) {
 259         kset(s, s->key, s->key, s->keylen);
 260     }
 261     if (!memcmp(oc->r_val, (const uint8_t[8]){0}, 8) ||
 262         rprobe(s, gdata, geob->datasize, oc->r_val) < 0 &&
 263         nprobe(s, gdata, geob->datasize, oc->n_val) < 0) {
 264         int i;
 265         for (i = 0; i < FF_ARRAY_ELEMS(leaf_table); i += 2) {
 266             uint8_t buf[16];
 267             AV_WL64(buf,     leaf_table[i]);
 268             AV_WL64(&buf[8], leaf_table[i + 1]);
 269             kset(s, buf, buf, 16);
 270             if (!rprobe(s, gdata, geob->datasize, oc->r_val) ||
 271                 !nprobe(s, gdata, geob->datasize, oc->n_val))
 272                 break;
 273         }
 274         if (i >= FF_ARRAY_ELEMS(leaf_table)) {
 275             av_log(s, AV_LOG_ERROR, "Invalid key\n");
 276             return AVERROR_INVALIDDATA;
 277         }
 278     }
 279
 280     /* e_val */
 281     av_des_init(&oc->av_des, oc->m_val, 64, 0);
 282     av_des_crypt(&oc->av_des, oc->e_val,
 283                  &gdata[OMA_ENC_HEADER_SIZE + 40], 1, NULL, 0);
 284     hex_log(s, AV_LOG_DEBUG, "EK", oc->e_val, 8);
 285
 286     /* init e_val */
 287     av_des_init(&oc->av_des, oc->e_val, 64, 1);
 288
 289     return 0;
 290 }
 291
 292 static int oma_read_header(AVFormatContext *s)
 293 {
 294     int     ret, framesize, jsflag, samplerate;
 295     uint32_t codec_params, channel_id;
 296     int16_t eid;
 297     uint8_t buf[EA3_HEADER_SIZE];
 298     uint8_t *edata;
 299     AVStream *st;
 300     ID3v2ExtraMeta *extra_meta = NULL;
 301     OMAContext *oc = s->priv_data;
 302
 303     ff_id3v2_read(s, ID3v2_EA3_MAGIC, &extra_meta);
 304     ret = avio_read(s->pb, buf, EA3_HEADER_SIZE);
 305     if (ret < EA3_HEADER_SIZE)
 306         return -1;
 307
 308     if (memcmp(buf, ((const uint8_t[]){'E', 'A', '3'}), 3) ||
 309         buf[4] != 0 || buf[5] != EA3_HEADER_SIZE) {
 310         av_log(s, AV_LOG_ERROR, "Couldn't find the EA3 header !\n");
 311         return AVERROR_INVALIDDATA;
 312     }
 313
 314     oc->content_start = avio_tell(s->pb);
 315
 316     /* encrypted file */
 317     eid = AV_RB16(&buf[6]);
 318     if (eid != -1 && eid != -128 && decrypt_init(s, extra_meta, buf) < 0) {
 319         ff_id3v2_free_extra_meta(&extra_meta);
 320         return -1;
 321     }
 322
 323     ff_id3v2_free_extra_meta(&extra_meta);
 324
 325     codec_params = AV_RB24(&buf[33]);
 326
 327     st = avformat_new_stream(s, NULL);
 328     if (!st)
 329         return AVERROR(ENOMEM);
 330
 331     st->start_time = 0;
 332     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
 333     st->codec->codec_tag  = buf[32];
 334     st->codec->codec_id   = ff_codec_get_id(ff_oma_codec_tags,
 335                                             st->codec->codec_tag);
 336
 337     switch (buf[32]) {
 338     case OMA_CODECID_ATRAC3:
 339         samplerate = ff_oma_srate_tab[(codec_params >> 13) & 7] * 100;
 340         if (!samplerate) {
 341             av_log(s, AV_LOG_ERROR, "Unsupported sample rate\n");
 342             return AVERROR_INVALIDDATA;
 343         }
 344         if (samplerate != 44100)
 345             avpriv_request_sample(s, "Sample rate %d", samplerate);
 346
 347         framesize = (codec_params & 0x3FF) * 8;
 348
 349         /* get stereo coding mode, 1 for joint-stereo */
 350         jsflag = (codec_params >> 17) & 1;
 351
 352         st->codec->channels    = 2;
 353         st->codec->channel_layout = AV_CH_LAYOUT_STEREO;
 354         st->codec->sample_rate = samplerate;
 355         st->codec->bit_rate    = st->codec->sample_rate * framesize * 8 / 1024;
 356
 357         /* fake the ATRAC3 extradata
 358          * (wav format, makes stream copy to wav work) */
 359         st->codec->extradata_size = 14;
 360         edata = av_mallocz(14 + FF_INPUT_BUFFER_PADDING_SIZE);
 361         if (!edata)
 362             return AVERROR(ENOMEM);
 363
 364         st->codec->extradata = edata;
 365         AV_WL16(&edata[0],  1);             // always 1
 366         AV_WL32(&edata[2],  samplerate);    // samples rate
 367         AV_WL16(&edata[6],  jsflag);        // coding mode
 368         AV_WL16(&edata[8],  jsflag);        // coding mode
 369         AV_WL16(&edata[10], 1);             // always 1
 370         // AV_WL16(&edata[12], 0);          // always 0
 371
 372         avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
 373         break;
 374     case OMA_CODECID_ATRAC3P:
 375         channel_id = (codec_params >> 10) & 7;
 376         if (!channel_id) {
 377             av_log(s, AV_LOG_ERROR,
 378                    "Invalid ATRAC-X channel id: %"PRIu32"\n", channel_id);
 379             return AVERROR_INVALIDDATA;
 380         }
 381         st->codec->channel_layout = ff_oma_chid_to_native_layout[channel_id - 1];
 382         st->codec->channels       = ff_oma_chid_to_num_channels[channel_id - 1];
 383         framesize = ((codec_params & 0x3FF) * 8) + 8;
 384         samplerate = ff_oma_srate_tab[(codec_params >> 13) & 7] * 100;
 385         if (!samplerate) {
 386             av_log(s, AV_LOG_ERROR, "Unsupported sample rate\n");
 387             return AVERROR_INVALIDDATA;
 388         }
 389         st->codec->sample_rate = samplerate;
 390         st->codec->bit_rate    = samplerate * framesize * 8 / 2048;
 391         avpriv_set_pts_info(st, 64, 1, samplerate);
 392         break;
 393     case OMA_CODECID_MP3:
 394         st->need_parsing = AVSTREAM_PARSE_FULL;
 395         framesize = 1024;
 396         break;
 397     case OMA_CODECID_LPCM:
 398         /* PCM 44.1 kHz 16 bit stereo big-endian */
 399         st->codec->channels = 2;
 400         st->codec->channel_layout = AV_CH_LAYOUT_STEREO;
 401         st->codec->sample_rate = 44100;
 402         framesize = 1024;
 403         /* bit rate = sample rate x PCM block align (= 4) x 8 */
 404         st->codec->bit_rate = st->codec->sample_rate * 32;
 405         st->codec->bits_per_coded_sample =
 406             av_get_bits_per_sample(st->codec->codec_id);
 407         avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
 408         break;
 409     default:
 410         av_log(s, AV_LOG_ERROR, "Unsupported codec %d!\n", buf[32]);
 411         return AVERROR(ENOSYS);
 412     }
 413
 414     st->codec->block_align = framesize;
 415
 416     return 0;
 417 }
 418
 419
 420 static int oma_read_packet(AVFormatContext *s, AVPacket *pkt)
 421 {
 422     OMAContext *oc  = s->priv_data;
 423     AVStream *st    = s->streams[0];
 424     int packet_size = st->codec->block_align;
 425     int byte_rate   = st->codec->bit_rate >> 3;
 426     int64_t pos     = avio_tell(s->pb);
 427     int ret         = av_get_packet(s->pb, pkt, packet_size);
 428
 429     if (ret < packet_size)
 430         pkt->flags |= AV_PKT_FLAG_CORRUPT;
 431
 432     if (ret < 0)
 433         return ret;
 434     if (!ret)
 435         return AVERROR_EOF;
 436
 437     pkt->stream_index = 0;
 438
 439     if (pos > 0) {
 440         pkt->pts =
 441         pkt->dts = av_rescale(pos, st->time_base.den,
 442                               byte_rate * (int64_t)st->time_base.num);
 443     }
 444
 445     if (oc->encrypted) {
 446         /* previous unencrypted block saved in IV for
 447          * the next packet (CBC mode) */
 448         if (ret == packet_size)
 449             av_des_crypt(&oc->av_des, pkt->data, pkt->data,
 450                          (packet_size >> 3), oc->iv, 1);
 451         else
 452             memset(oc->iv, 0, 8);
 453     }
 454
 455     return ret;
 456 }
 457
 458 static int oma_read_probe(AVProbeData *p)
 459 {
 460     const uint8_t *buf = p->buf;
 461     unsigned tag_len = 0;
 462
 463     if (p->buf_size >= ID3v2_HEADER_SIZE && ff_id3v2_match(buf, ID3v2_EA3_MAGIC))
 464         tag_len = ff_id3v2_tag_len(buf);
 465
 466     /* This check cannot overflow as tag_len has at most 28 bits */
 467     if (p->buf_size < tag_len + 5)
 468         /* EA3 header comes late, might be outside of the probe buffer */
 469         return tag_len ? AVPROBE_SCORE_EXTENSION : 0;
 470
 471     buf += tag_len;
 472
 473     if (!memcmp(buf, "EA3", 3) && !buf[4] && buf[5] == EA3_HEADER_SIZE)
 474         return AVPROBE_SCORE_MAX;
 475     else
 476         return 0;
 477 }
 478
 479 static int oma_read_seek(struct AVFormatContext *s,
 480                          int stream_index, int64_t timestamp, int flags)
 481 {
 482     OMAContext *oc = s->priv_data;
 483     int err = ff_pcm_read_seek(s, stream_index, timestamp, flags);
 484
 485     if (!oc->encrypted)
 486         return err;
 487
 488     /* readjust IV for CBC */
 489     if (err || avio_tell(s->pb) < oc->content_start)
 490         goto wipe;
 491     if ((err = avio_seek(s->pb, -8, SEEK_CUR)) < 0)
 492         goto wipe;
 493     if ((err = avio_read(s->pb, oc->iv, 8)) < 8) {
 494         if (err >= 0)
 495             err = AVERROR_EOF;
 496         goto wipe;
 497     }
 498
 499     return 0;
 500 wipe:
 501     memset(oc->iv, 0, 8);
 502     return err;
 503 }
 504
 505 AVInputFormat ff_oma_demuxer = {
 506     .name           = "oma",
 507     .long_name      = NULL_IF_CONFIG_SMALL("Sony OpenMG audio"),
 508     .priv_data_size = sizeof(OMAContext),
 509     .read_probe     = oma_read_probe,
 510     .read_header    = oma_read_header,
 511     .read_packet    = oma_read_packet,
 512     .read_seek      = oma_read_seek,
 513     .flags          = AVFMT_GENERIC_INDEX,
 514     .extensions     = "oma,omg,aa3",
 515     .codec_tag      = (const AVCodecTag* const []){ff_oma_codec_tags, 0},
 516 };