libavformat/oma.c

   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
  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  * CODEC SUPPORT: Only ATRAC3 codec is currently supported!
  41  */
  42
  43 #include "avformat.h"
  44 #include "internal.h"
  45 #include "libavutil/intreadwrite.h"
  46 #include "libavutil/des.h"
  47 #include "pcm.h"
  48 #include "riff.h"
  49 #include "id3v2.h"
  50
  51 #define EA3_HEADER_SIZE 96
  52 #define ID3v2_EA3_MAGIC "ea3"
  53 #define OMA_ENC_HEADER_SIZE 16
  54
  55 enum {
  56     OMA_CODECID_ATRAC3  = 0,
  57     OMA_CODECID_ATRAC3P = 1,
  58     OMA_CODECID_MP3     = 3,
  59     OMA_CODECID_LPCM    = 4,
  60     OMA_CODECID_WMA     = 5,
  61 };
  62
  63 static const AVCodecTag codec_oma_tags[] = {
  64     { CODEC_ID_ATRAC3,      OMA_CODECID_ATRAC3 },
  65     { CODEC_ID_ATRAC3P,     OMA_CODECID_ATRAC3P },
  66     { CODEC_ID_MP3,         OMA_CODECID_MP3 },
  67     { CODEC_ID_PCM_S16BE,   OMA_CODECID_LPCM },
  68 };
  69
  70 static const uint64_t leaf_table[] = {
  71     0xd79e8283acea4620, 0x7a9762f445afd0d8,
  72     0x354d60a60b8c79f1, 0x584e1cde00b07aee,
  73     0x1573cd93da7df623, 0x47f98d79620dd535
  74 };
  75
  76 typedef struct OMAContext {
  77     uint64_t content_start;
  78     int encrypted;
  79     uint16_t k_size;
  80     uint16_t e_size;
  81     uint16_t i_size;
  82     uint16_t s_size;
  83     uint32_t rid;
  84     uint8_t r_val[24];
  85     uint8_t n_val[24];
  86     uint8_t m_val[8];
  87     uint8_t s_val[8];
  88     uint8_t sm_val[8];
  89     uint8_t e_val[8];
  90     uint8_t iv[8];
  91     struct AVDES av_des;
  92 } OMAContext;
  93
  94 static void hex_log(AVFormatContext *s, int level, const char *name, const uint8_t *value, int len)
  95 {
  96     char buf[33];
  97     len = FFMIN(len, 16);
  98     if (av_log_get_level() < level)
  99         return;
 100     ff_data_to_hex(buf, value, len, 1);
 101     buf[len<<1] = '\0';
 102     av_log(s, level, "%s: %s\n", name, buf);
 103 }
 104
 105 static int kset(AVFormatContext *s, const uint8_t *r_val, const uint8_t *n_val, int len)
 106 {
 107     OMAContext *oc = s->priv_data;
 108
 109     if (!r_val && !n_val)
 110         return -1;
 111
 112     len = FFMIN(len, 16);
 113
 114     /* use first 64 bits in the third round again */
 115     if (r_val) {
 116         if (r_val != oc->r_val) {
 117             memset(oc->r_val, 0, 24);
 118             memcpy(oc->r_val, r_val, len);
 119         }
 120         memcpy(&oc->r_val[16], r_val, 8);
 121     }
 122     if (n_val) {
 123         if (n_val != oc->n_val) {
 124             memset(oc->n_val, 0, 24);
 125             memcpy(oc->n_val, n_val, len);
 126         }
 127         memcpy(&oc->n_val[16], n_val, 8);
 128     }
 129
 130     return 0;
 131 }
 132
 133 static int rprobe(AVFormatContext *s, uint8_t *enc_header, const uint8_t *r_val)
 134 {
 135     OMAContext *oc = s->priv_data;
 136     unsigned int pos;
 137     struct AVDES av_des;
 138
 139     if (!enc_header || !r_val)
 140         return -1;
 141
 142     /* m_val */
 143     av_des_init(&av_des, r_val, 192, 1);
 144     av_des_crypt(&av_des, oc->m_val, &enc_header[48], 1, NULL, 1);
 145
 146     /* s_val */
 147     av_des_init(&av_des, oc->m_val, 64, 0);
 148     av_des_crypt(&av_des, oc->s_val, NULL, 1, NULL, 0);
 149
 150     /* sm_val */
 151     pos = OMA_ENC_HEADER_SIZE + oc->k_size + oc->e_size;
 152     av_des_init(&av_des, oc->s_val, 64, 0);
 153     av_des_mac(&av_des, oc->sm_val, &enc_header[pos], (oc->i_size >> 3));
 154
 155     pos += oc->i_size;
 156
 157     return memcmp(&enc_header[pos], oc->sm_val, 8) ? -1 : 0;
 158 }
 159
 160 static int nprobe(AVFormatContext *s, uint8_t *enc_header, const uint8_t *n_val)
 161 {
 162     OMAContext *oc = s->priv_data;
 163     uint32_t pos, taglen, datalen;
 164     struct AVDES av_des;
 165
 166     if (!enc_header || !n_val)
 167         return -1;
 168
 169     pos = OMA_ENC_HEADER_SIZE + oc->k_size;
 170     if (!memcmp(&enc_header[pos], "EKB ", 4))
 171         pos += 32;
 172
 173     if (AV_RB32(&enc_header[pos]) != oc->rid)
 174         av_log(s, AV_LOG_DEBUG, "Mismatching RID\n");
 175
 176     taglen = AV_RB32(&enc_header[pos+32]);
 177     datalen = AV_RB32(&enc_header[pos+36]) >> 4;
 178
 179     pos += 44 + taglen;
 180
 181     av_des_init(&av_des, n_val, 192, 1);
 182     while (datalen-- > 0) {
 183         av_des_crypt(&av_des, oc->r_val, &enc_header[pos], 2, NULL, 1);
 184         kset(s, oc->r_val, NULL, 16);
 185         if (!rprobe(s, enc_header, oc->r_val))
 186             return 0;
 187         pos += 16;
 188     }
 189
 190     return -1;
 191 }
 192
 193 static int decrypt_init(AVFormatContext *s, ID3v2ExtraMeta *em, uint8_t *header)
 194 {
 195     OMAContext *oc = s->priv_data;
 196     ID3v2ExtraMetaGEOB *geob = NULL;
 197     uint8_t *gdata;
 198
 199     oc->encrypted = 1;
 200     av_log(s, AV_LOG_INFO, "File is encrypted\n");
 201
 202     /* find GEOB metadata */
 203     while (em) {
 204         if (!strcmp(em->tag, "GEOB") &&
 205             (geob = em->data) &&
 206             (!strcmp(geob->description, "OMG_LSI") ||
 207              !strcmp(geob->description, "OMG_BKLSI"))) {
 208             break;
 209         }
 210         em = em->next;
 211     }
 212     if (!em) {
 213         av_log(s, AV_LOG_ERROR, "No encryption header found\n");
 214         return -1;
 215     }
 216
 217     if (geob->datasize < 64) {
 218         av_log(s, AV_LOG_ERROR, "Invalid GEOB data size: %u\n", geob->datasize);
 219         return -1;
 220     }
 221
 222     gdata = geob->data;
 223
 224     if (AV_RB16(gdata) != 1)
 225         av_log(s, AV_LOG_WARNING, "Unknown version in encryption header\n");
 226
 227     oc->k_size = AV_RB16(&gdata[2]);
 228     oc->e_size = AV_RB16(&gdata[4]);
 229     oc->i_size = AV_RB16(&gdata[6]);
 230     oc->s_size = AV_RB16(&gdata[8]);
 231
 232     if (memcmp(&gdata[OMA_ENC_HEADER_SIZE], "KEYRING     ", 12)) {
 233         av_log(s, AV_LOG_ERROR, "Invalid encryption header\n");
 234         return -1;
 235     }
 236     oc->rid = AV_RB32(&gdata[OMA_ENC_HEADER_SIZE + 28]);
 237     av_log(s, AV_LOG_DEBUG, "RID: %.8x\n", oc->rid);
 238
 239     memcpy(oc->iv, &header[0x58], 8);
 240     hex_log(s, AV_LOG_DEBUG, "IV", oc->iv, 8);
 241
 242     hex_log(s, AV_LOG_DEBUG, "CBC-MAC", &gdata[OMA_ENC_HEADER_SIZE+oc->k_size+oc->e_size+oc->i_size], 8);
 243
 244     if (s->keylen > 0) {
 245         kset(s, s->key, s->key, s->keylen);
 246     }
 247     if (!memcmp(oc->r_val, (const uint8_t[8]){0}, 8) ||
 248         rprobe(s, gdata, oc->r_val) < 0 &&
 249         nprobe(s, gdata, oc->n_val) < 0) {
 250         int i;
 251         for (i = 0; i < sizeof(leaf_table); i += 2) {
 252             uint8_t buf[16];
 253             AV_WL64(buf, leaf_table[i]);
 254             AV_WL64(&buf[8], leaf_table[i+1]);
 255             kset(s, buf, buf, 16);
 256             if (!rprobe(s, gdata, oc->r_val) || !nprobe(s, gdata, oc->n_val))
 257                 break;
 258         }
 259         if (i >= sizeof(leaf_table)) {
 260             av_log(s, AV_LOG_ERROR, "Invalid key\n");
 261             return -1;
 262         }
 263     }
 264
 265     /* e_val */
 266     av_des_init(&oc->av_des, oc->m_val, 64, 0);
 267     av_des_crypt(&oc->av_des, oc->e_val, &gdata[OMA_ENC_HEADER_SIZE + 40], 1, NULL, 0);
 268     hex_log(s, AV_LOG_DEBUG, "EK", oc->e_val, 8);
 269
 270     /* init e_val */
 271     av_des_init(&oc->av_des, oc->e_val, 64, 1);
 272
 273     return 0;
 274 }
 275
 276 static int oma_read_header(AVFormatContext *s,
 277                            AVFormatParameters *ap)
 278 {
 279     static const uint16_t srate_tab[6] = {320,441,480,882,960,0};
 280     int     ret, framesize, jsflag, samplerate;
 281     uint32_t codec_params;
 282     int16_t eid;
 283     uint8_t buf[EA3_HEADER_SIZE];
 284     uint8_t *edata;
 285     AVStream *st;
 286     ID3v2ExtraMeta *extra_meta = NULL;
 287     OMAContext *oc = s->priv_data;
 288
 289     ff_id3v2_read_all(s, ID3v2_EA3_MAGIC, &extra_meta);
 290     ret = avio_read(s->pb, buf, EA3_HEADER_SIZE);
 291     if (ret < EA3_HEADER_SIZE)
 292         return -1;
 293
 294     if (memcmp(buf, ((const uint8_t[]){'E', 'A', '3'}),3) || buf[4] != 0 || buf[5] != EA3_HEADER_SIZE) {
 295         av_log(s, AV_LOG_ERROR, "Couldn't find the EA3 header !\n");
 296         return -1;
 297     }
 298
 299     oc->content_start = avio_tell(s->pb);
 300
 301     /* encrypted file */
 302     eid = AV_RB16(&buf[6]);
 303     if (eid != -1 && eid != -128 && decrypt_init(s, extra_meta, buf) < 0) {
 304         ff_id3v2_free_extra_meta(&extra_meta);
 305         return -1;
 306     }
 307
 308     ff_id3v2_free_extra_meta(&extra_meta);
 309
 310     codec_params = AV_RB24(&buf[33]);
 311
 312     st = avformat_new_stream(s, NULL);
 313     if (!st)
 314         return AVERROR(ENOMEM);
 315
 316     st->start_time = 0;
 317     st->codec->codec_type  = AVMEDIA_TYPE_AUDIO;
 318     st->codec->codec_tag   = buf[32];
 319     st->codec->codec_id    = ff_codec_get_id(codec_oma_tags, st->codec->codec_tag);
 320
 321     switch (buf[32]) {
 322         case OMA_CODECID_ATRAC3:
 323             samplerate = srate_tab[(codec_params >> 13) & 7]*100;
 324             if (samplerate != 44100)
 325                 av_log_ask_for_sample(s, "Unsupported sample rate: %d\n",
 326                                       samplerate);
 327
 328             framesize = (codec_params & 0x3FF) * 8;
 329             jsflag = (codec_params >> 17) & 1; /* get stereo coding mode, 1 for joint-stereo */
 330             st->codec->channels    = 2;
 331             st->codec->sample_rate = samplerate;
 332             st->codec->bit_rate    = st->codec->sample_rate * framesize * 8 / 1024;
 333
 334             /* fake the atrac3 extradata (wav format, makes stream copy to wav work) */
 335             st->codec->extradata_size = 14;
 336             edata = av_mallocz(14 + FF_INPUT_BUFFER_PADDING_SIZE);
 337             if (!edata)
 338                 return AVERROR(ENOMEM);
 339
 340             st->codec->extradata = edata;
 341             AV_WL16(&edata[0],  1);             // always 1
 342             AV_WL32(&edata[2],  samplerate);    // samples rate
 343             AV_WL16(&edata[6],  jsflag);        // coding mode
 344             AV_WL16(&edata[8],  jsflag);        // coding mode
 345             AV_WL16(&edata[10], 1);             // always 1
 346             // AV_WL16(&edata[12], 0);          // always 0
 347
 348             avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
 349             break;
 350         case OMA_CODECID_ATRAC3P:
 351             st->codec->channels = (codec_params >> 10) & 7;
 352             framesize = ((codec_params & 0x3FF) * 8) + 8;
 353             st->codec->sample_rate = srate_tab[(codec_params >> 13) & 7]*100;
 354             st->codec->bit_rate    = st->codec->sample_rate * framesize * 8 / 1024;
 355             avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
 356             av_log(s, AV_LOG_ERROR, "Unsupported codec ATRAC3+!\n");
 357             break;
 358         case OMA_CODECID_MP3:
 359             st->need_parsing = AVSTREAM_PARSE_FULL;
 360             framesize = 1024;
 361             break;
 362         case OMA_CODECID_LPCM:
 363             /* PCM 44.1 kHz 16 bit stereo big-endian */
 364             st->codec->channels = 2;
 365             st->codec->sample_rate = 44100;
 366             framesize = 1024;
 367             /* bit rate = sample rate x PCM block align (= 4) x 8 */
 368             st->codec->bit_rate = st->codec->sample_rate * 32;
 369             st->codec->bits_per_coded_sample = av_get_bits_per_sample(st->codec->codec_id);
 370             avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
 371             break;
 372         default:
 373             av_log(s, AV_LOG_ERROR, "Unsupported codec %d!\n",buf[32]);
 374             return -1;
 375     }
 376
 377     st->codec->block_align = framesize;
 378
 379     return 0;
 380 }
 381
 382
 383 static int oma_read_packet(AVFormatContext *s, AVPacket *pkt)
 384 {
 385     OMAContext *oc = s->priv_data;
 386     int packet_size = s->streams[0]->codec->block_align;
 387     int ret = av_get_packet(s->pb, pkt, packet_size);
 388
 389     if (ret <= 0)
 390         return AVERROR(EIO);
 391
 392     pkt->stream_index = 0;
 393
 394     if (oc->encrypted) {
 395         /* previous unencrypted block saved in IV for the next packet (CBC mode) */
 396         av_des_crypt(&oc->av_des, pkt->data, pkt->data, (packet_size >> 3), oc->iv, 1);
 397     }
 398
 399     return ret;
 400 }
 401
 402 static int oma_read_probe(AVProbeData *p)
 403 {
 404     const uint8_t *buf;
 405     unsigned tag_len = 0;
 406
 407     buf = p->buf;
 408
 409     if (p->buf_size < ID3v2_HEADER_SIZE ||
 410         !ff_id3v2_match(buf, ID3v2_EA3_MAGIC) ||
 411         buf[3] != 3 || // version must be 3
 412         buf[4]) // flags byte zero
 413         return 0;
 414
 415     tag_len = ff_id3v2_tag_len(buf);
 416
 417     /* This check cannot overflow as tag_len has at most 28 bits */
 418     if (p->buf_size < tag_len + 5)
 419         /* EA3 header comes late, might be outside of the probe buffer */
 420         return AVPROBE_SCORE_MAX / 2;
 421
 422     buf += tag_len;
 423
 424     if (!memcmp(buf, "EA3", 3) && !buf[4] && buf[5] == EA3_HEADER_SIZE)
 425         return AVPROBE_SCORE_MAX;
 426     else
 427         return 0;
 428 }
 429
 430 static int oma_read_seek(struct AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
 431 {
 432     OMAContext *oc = s->priv_data;
 433
 434     pcm_read_seek(s, stream_index, timestamp, flags);
 435
 436     if (oc->encrypted) {
 437         /* readjust IV for CBC */
 438         int64_t pos = avio_tell(s->pb);
 439         if (pos < oc->content_start)
 440             memset(oc->iv, 0, 8);
 441         else {
 442             if (avio_seek(s->pb, -8, SEEK_CUR) < 0 || avio_read(s->pb, oc->iv, 8) < 8) {
 443                 memset(oc->iv, 0, 8);
 444                 return -1;
 445             }
 446         }
 447     }
 448
 449     return 0;
 450 }
 451
 452 AVInputFormat ff_oma_demuxer = {
 453     .name           = "oma",
 454     .long_name      = NULL_IF_CONFIG_SMALL("Sony OpenMG audio"),
 455     .priv_data_size = sizeof(OMAContext),
 456     .read_probe     = oma_read_probe,
 457     .read_header    = oma_read_header,
 458     .read_packet    = oma_read_packet,
 459     .read_seek      = oma_read_seek,
 460     .flags          = AVFMT_GENERIC_INDEX,
 461     .extensions     = "oma,omg,aa3",
 462     .codec_tag      = (const AVCodecTag* const []){codec_oma_tags, 0},
 463 };
 464