FFmpeg: libavformat/omadec.c Source File

00001 /*
00002  * Sony OpenMG (OMA) demuxer
00003  *
00004  * Copyright (c) 2008 Maxim Poliakovski
00005  *               2008 Benjamin Larsson
00006  *               2011 David Goldwich
00007  *
00008  * This file is part of FFmpeg.
00009  *
00010  * FFmpeg is free software; you can redistribute it and/or
00011  * modify it under the terms of the GNU Lesser General Public
00012  * License as published by the Free Software Foundation; either
00013  * version 2.1 of the License, or (at your option) any later version.
00014  *
00015  * FFmpeg is distributed in the hope that it will be useful,
00016  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00017  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00018  * Lesser General Public License for more details.
00019  *
00020  * You should have received a copy of the GNU Lesser General Public
00021  * License along with FFmpeg; if not, write to the Free Software
00022  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00023  */
00024 
00042 #include "libavutil/channel_layout.h"
00043 #include "avformat.h"
00044 #include "internal.h"
00045 #include "libavutil/intreadwrite.h"
00046 #include "libavutil/des.h"
00047 #include "oma.h"
00048 #include "pcm.h"
00049 #include "id3v2.h"
00050 
00051 
00052 static const uint64_t leaf_table[] = {
00053     0xd79e8283acea4620, 0x7a9762f445afd0d8,
00054     0x354d60a60b8c79f1, 0x584e1cde00b07aee,
00055     0x1573cd93da7df623, 0x47f98d79620dd535
00056 };
00057 
00058 typedef struct OMAContext {
00059     uint64_t content_start;
00060     int encrypted;
00061     uint16_t k_size;
00062     uint16_t e_size;
00063     uint16_t i_size;
00064     uint16_t s_size;
00065     uint32_t rid;
00066     uint8_t r_val[24];
00067     uint8_t n_val[24];
00068     uint8_t m_val[8];
00069     uint8_t s_val[8];
00070     uint8_t sm_val[8];
00071     uint8_t e_val[8];
00072     uint8_t iv[8];
00073     struct AVDES av_des;
00074 } OMAContext;
00075 
00076 static void hex_log(AVFormatContext *s, int level, const char *name, const uint8_t *value, int len)
00077 {
00078     char buf[33];
00079     len = FFMIN(len, 16);
00080     if (av_log_get_level() < level)
00081         return;
00082     ff_data_to_hex(buf, value, len, 1);
00083     buf[len<<1] = '\0';
00084     av_log(s, level, "%s: %s\n", name, buf);
00085 }
00086 
00087 static int kset(AVFormatContext *s, const uint8_t *r_val, const uint8_t *n_val, int len)
00088 {
00089     OMAContext *oc = s->priv_data;
00090 
00091     if (!r_val && !n_val)
00092         return -1;
00093 
00094     len = FFMIN(len, 16);
00095 
00096     /* use first 64 bits in the third round again */
00097     if (r_val) {
00098         if (r_val != oc->r_val) {
00099             memset(oc->r_val, 0, 24);
00100             memcpy(oc->r_val, r_val, len);
00101         }
00102         memcpy(&oc->r_val[16], r_val, 8);
00103     }
00104     if (n_val) {
00105         if (n_val != oc->n_val) {
00106             memset(oc->n_val, 0, 24);
00107             memcpy(oc->n_val, n_val, len);
00108         }
00109         memcpy(&oc->n_val[16], n_val, 8);
00110     }
00111 
00112     return 0;
00113 }
00114 
00115 static int rprobe(AVFormatContext *s, uint8_t *enc_header, const uint8_t *r_val)
00116 {
00117     OMAContext *oc = s->priv_data;
00118     unsigned int pos;
00119     struct AVDES av_des;
00120 
00121     if (!enc_header || !r_val)
00122         return -1;
00123 
00124     /* m_val */
00125     av_des_init(&av_des, r_val, 192, 1);
00126     av_des_crypt(&av_des, oc->m_val, &enc_header[48], 1, NULL, 1);
00127 
00128     /* s_val */
00129     av_des_init(&av_des, oc->m_val, 64, 0);
00130     av_des_crypt(&av_des, oc->s_val, NULL, 1, NULL, 0);
00131 
00132     /* sm_val */
00133     pos = OMA_ENC_HEADER_SIZE + oc->k_size + oc->e_size;
00134     av_des_init(&av_des, oc->s_val, 64, 0);
00135     av_des_mac(&av_des, oc->sm_val, &enc_header[pos], (oc->i_size >> 3));
00136 
00137     pos += oc->i_size;
00138 
00139     return memcmp(&enc_header[pos], oc->sm_val, 8) ? -1 : 0;
00140 }
00141 
00142 static int nprobe(AVFormatContext *s, uint8_t *enc_header, int size, const uint8_t *n_val)
00143 {
00144     OMAContext *oc = s->priv_data;
00145     uint32_t pos, taglen, datalen;
00146     struct AVDES av_des;
00147 
00148     if (!enc_header || !n_val)
00149         return -1;
00150 
00151     pos = OMA_ENC_HEADER_SIZE + oc->k_size;
00152     if (!memcmp(&enc_header[pos], "EKB ", 4))
00153         pos += 32;
00154 
00155     if (AV_RB32(&enc_header[pos]) != oc->rid)
00156         av_log(s, AV_LOG_DEBUG, "Mismatching RID\n");
00157 
00158     taglen = AV_RB32(&enc_header[pos+32]);
00159     datalen = AV_RB32(&enc_header[pos+36]) >> 4;
00160 
00161     if(pos + (uint64_t)taglen + (((uint64_t)datalen)<<4) + 44 > size)
00162         return -1;
00163 
00164     pos += 44 + taglen;
00165 
00166     av_des_init(&av_des, n_val, 192, 1);
00167     while (datalen-- > 0) {
00168         av_des_crypt(&av_des, oc->r_val, &enc_header[pos], 2, NULL, 1);
00169         kset(s, oc->r_val, NULL, 16);
00170         if (!rprobe(s, enc_header, oc->r_val))
00171             return 0;
00172         pos += 16;
00173     }
00174 
00175     return -1;
00176 }
00177 
00178 static int decrypt_init(AVFormatContext *s, ID3v2ExtraMeta *em, uint8_t *header)
00179 {
00180     OMAContext *oc = s->priv_data;
00181     ID3v2ExtraMetaGEOB *geob = NULL;
00182     uint8_t *gdata;
00183 
00184     oc->encrypted = 1;
00185     av_log(s, AV_LOG_INFO, "File is encrypted\n");
00186 
00187     /* find GEOB metadata */
00188     while (em) {
00189         if (!strcmp(em->tag, "GEOB") &&
00190             (geob = em->data) &&
00191             (!strcmp(geob->description, "OMG_LSI") ||
00192              !strcmp(geob->description, "OMG_BKLSI"))) {
00193             break;
00194         }
00195         em = em->next;
00196     }
00197     if (!em) {
00198         av_log(s, AV_LOG_ERROR, "No encryption header found\n");
00199         return -1;
00200     }
00201 
00202     if (geob->datasize < 64) {
00203         av_log(s, AV_LOG_ERROR, "Invalid GEOB data size: %u\n", geob->datasize);
00204         return -1;
00205     }
00206 
00207     gdata = geob->data;
00208 
00209     if (AV_RB16(gdata) != 1)
00210         av_log(s, AV_LOG_WARNING, "Unknown version in encryption header\n");
00211 
00212     oc->k_size = AV_RB16(&gdata[2]);
00213     oc->e_size = AV_RB16(&gdata[4]);
00214     oc->i_size = AV_RB16(&gdata[6]);
00215     oc->s_size = AV_RB16(&gdata[8]);
00216 
00217     if (memcmp(&gdata[OMA_ENC_HEADER_SIZE], "KEYRING     ", 12)) {
00218         av_log(s, AV_LOG_ERROR, "Invalid encryption header\n");
00219         return -1;
00220     }
00221     if (   OMA_ENC_HEADER_SIZE + oc->k_size + oc->e_size + oc->i_size + 8 > geob->datasize
00222         || OMA_ENC_HEADER_SIZE + 48 > geob->datasize
00223     ) {
00224         av_log(s, AV_LOG_ERROR, "Too little GEOB data\n");
00225         return AVERROR_INVALIDDATA;
00226     }
00227     oc->rid = AV_RB32(&gdata[OMA_ENC_HEADER_SIZE + 28]);
00228     av_log(s, AV_LOG_DEBUG, "RID: %.8x\n", oc->rid);
00229 
00230     memcpy(oc->iv, &header[0x58], 8);
00231     hex_log(s, AV_LOG_DEBUG, "IV", oc->iv, 8);
00232 
00233     hex_log(s, AV_LOG_DEBUG, "CBC-MAC", &gdata[OMA_ENC_HEADER_SIZE+oc->k_size+oc->e_size+oc->i_size], 8);
00234 
00235     if (s->keylen > 0) {
00236         kset(s, s->key, s->key, s->keylen);
00237     }
00238     if (!memcmp(oc->r_val, (const uint8_t[8]){0}, 8) ||
00239         rprobe(s, gdata, oc->r_val) < 0 &&
00240         nprobe(s, gdata, geob->datasize, oc->n_val) < 0) {
00241         int i;
00242         for (i = 0; i < FF_ARRAY_ELEMS(leaf_table); i += 2) {
00243             uint8_t buf[16];
00244             AV_WL64(buf, leaf_table[i]);
00245             AV_WL64(&buf[8], leaf_table[i+1]);
00246             kset(s, buf, buf, 16);
00247             if (!rprobe(s, gdata, oc->r_val) || !nprobe(s, gdata, geob->datasize, oc->n_val))
00248                 break;
00249         }
00250         if (i >= FF_ARRAY_ELEMS(leaf_table)) {
00251             av_log(s, AV_LOG_ERROR, "Invalid key\n");
00252             return -1;
00253         }
00254     }
00255 
00256     /* e_val */
00257     av_des_init(&oc->av_des, oc->m_val, 64, 0);
00258     av_des_crypt(&oc->av_des, oc->e_val, &gdata[OMA_ENC_HEADER_SIZE + 40], 1, NULL, 0);
00259     hex_log(s, AV_LOG_DEBUG, "EK", oc->e_val, 8);
00260 
00261     /* init e_val */
00262     av_des_init(&oc->av_des, oc->e_val, 64, 1);
00263 
00264     return 0;
00265 }
00266 
00267 static int oma_read_header(AVFormatContext *s)
00268 {
00269     int     ret, framesize, jsflag, samplerate;
00270     uint32_t codec_params;
00271     int16_t eid;
00272     uint8_t buf[EA3_HEADER_SIZE];
00273     uint8_t *edata;
00274     AVStream *st;
00275     ID3v2ExtraMeta *extra_meta = NULL;
00276     OMAContext *oc = s->priv_data;
00277 
00278     ff_id3v2_read(s, ID3v2_EA3_MAGIC, &extra_meta);
00279     ret = avio_read(s->pb, buf, EA3_HEADER_SIZE);
00280     if (ret < EA3_HEADER_SIZE)
00281         return -1;
00282 
00283     if (memcmp(buf, ((const uint8_t[]){'E', 'A', '3'}),3) || buf[4] != 0 || buf[5] != EA3_HEADER_SIZE) {
00284         av_log(s, AV_LOG_ERROR, "Couldn't find the EA3 header !\n");
00285         return -1;
00286     }
00287 
00288     oc->content_start = avio_tell(s->pb);
00289 
00290     /* encrypted file */
00291     eid = AV_RB16(&buf[6]);
00292     if (eid != -1 && eid != -128 && decrypt_init(s, extra_meta, buf) < 0) {
00293         ff_id3v2_free_extra_meta(&extra_meta);
00294         return -1;
00295     }
00296 
00297     ff_id3v2_free_extra_meta(&extra_meta);
00298 
00299     codec_params = AV_RB24(&buf[33]);
00300 
00301     st = avformat_new_stream(s, NULL);
00302     if (!st)
00303         return AVERROR(ENOMEM);
00304 
00305     st->start_time = 0;
00306     st->codec->codec_type  = AVMEDIA_TYPE_AUDIO;
00307     st->codec->codec_tag   = buf[32];
00308     st->codec->codec_id    = ff_codec_get_id(ff_oma_codec_tags, st->codec->codec_tag);
00309 
00310     switch (buf[32]) {
00311         case OMA_CODECID_ATRAC3:
00312             samplerate = ff_oma_srate_tab[(codec_params >> 13) & 7]*100;
00313             if (samplerate != 44100)
00314                 av_log_ask_for_sample(s, "Unsupported sample rate: %d\n",
00315                                       samplerate);
00316 
00317             framesize = (codec_params & 0x3FF) * 8;
00318             jsflag = (codec_params >> 17) & 1; /* get stereo coding mode, 1 for joint-stereo */
00319             st->codec->channels    = 2;
00320             st->codec->channel_layout = AV_CH_LAYOUT_STEREO;
00321             st->codec->sample_rate = samplerate;
00322             st->codec->bit_rate    = st->codec->sample_rate * framesize * 8 / 1024;
00323 
00324             /* fake the atrac3 extradata (wav format, makes stream copy to wav work) */
00325             st->codec->extradata_size = 14;
00326             edata = av_mallocz(14 + FF_INPUT_BUFFER_PADDING_SIZE);
00327             if (!edata)
00328                 return AVERROR(ENOMEM);
00329 
00330             st->codec->extradata = edata;
00331             AV_WL16(&edata[0],  1);             // always 1
00332             AV_WL32(&edata[2],  samplerate);    // samples rate
00333             AV_WL16(&edata[6],  jsflag);        // coding mode
00334             AV_WL16(&edata[8],  jsflag);        // coding mode
00335             AV_WL16(&edata[10], 1);             // always 1
00336             // AV_WL16(&edata[12], 0);          // always 0
00337 
00338             avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
00339             break;
00340         case OMA_CODECID_ATRAC3P:
00341             st->codec->channels = (codec_params >> 10) & 7;
00342             framesize = ((codec_params & 0x3FF) * 8) + 8;
00343             st->codec->sample_rate = ff_oma_srate_tab[(codec_params >> 13) & 7]*100;
00344             st->codec->bit_rate    = st->codec->sample_rate * framesize * 8 / 1024;
00345             avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
00346             av_log(s, AV_LOG_ERROR, "Unsupported codec ATRAC3+!\n");
00347             break;
00348         case OMA_CODECID_MP3:
00349             st->need_parsing = AVSTREAM_PARSE_FULL_RAW;
00350             framesize = 1024;
00351             break;
00352         case OMA_CODECID_LPCM:
00353             /* PCM 44.1 kHz 16 bit stereo big-endian */
00354             st->codec->channels = 2;
00355             st->codec->channel_layout = AV_CH_LAYOUT_STEREO;
00356             st->codec->sample_rate = 44100;
00357             framesize = 1024;
00358             /* bit rate = sample rate x PCM block align (= 4) x 8 */
00359             st->codec->bit_rate = st->codec->sample_rate * 32;
00360             st->codec->bits_per_coded_sample = av_get_bits_per_sample(st->codec->codec_id);
00361             avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
00362             break;
00363         default:
00364             av_log(s, AV_LOG_ERROR, "Unsupported codec %d!\n",buf[32]);
00365             return -1;
00366     }
00367 
00368     st->codec->block_align = framesize;
00369 
00370     return 0;
00371 }
00372 
00373 
00374 static int oma_read_packet(AVFormatContext *s, AVPacket *pkt)
00375 {
00376     OMAContext *oc = s->priv_data;
00377     int packet_size = s->streams[0]->codec->block_align;
00378     int ret = av_get_packet(s->pb, pkt, packet_size);
00379 
00380     if (ret <= 0)
00381         return AVERROR(EIO);
00382 
00383     pkt->stream_index = 0;
00384 
00385     if (oc->encrypted) {
00386         /* previous unencrypted block saved in IV for the next packet (CBC mode) */
00387         av_des_crypt(&oc->av_des, pkt->data, pkt->data, (ret >> 3), oc->iv, 1);
00388     }
00389 
00390     return ret;
00391 }
00392 
00393 static int oma_read_probe(AVProbeData *p)
00394 {
00395     const uint8_t *buf;
00396     unsigned tag_len = 0;
00397 
00398     buf = p->buf;
00399 
00400     if (p->buf_size < ID3v2_HEADER_SIZE ||
00401         !ff_id3v2_match(buf, ID3v2_EA3_MAGIC) ||
00402         buf[3] != 3 || // version must be 3
00403         buf[4]) // flags byte zero
00404         return 0;
00405 
00406     tag_len = ff_id3v2_tag_len(buf);
00407 
00408     /* This check cannot overflow as tag_len has at most 28 bits */
00409     if (p->buf_size < tag_len + 5)
00410         /* EA3 header comes late, might be outside of the probe buffer */
00411         return AVPROBE_SCORE_MAX / 2;
00412 
00413     buf += tag_len;
00414 
00415     if (!memcmp(buf, "EA3", 3) && !buf[4] && buf[5] == EA3_HEADER_SIZE)
00416         return AVPROBE_SCORE_MAX;
00417     else
00418         return 0;
00419 }
00420 
00421 static int oma_read_seek(struct AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
00422 {
00423     OMAContext *oc = s->priv_data;
00424 
00425     ff_pcm_read_seek(s, stream_index, timestamp, flags);
00426 
00427     if (oc->encrypted) {
00428         /* readjust IV for CBC */
00429         int64_t pos = avio_tell(s->pb);
00430         if (pos < oc->content_start)
00431             memset(oc->iv, 0, 8);
00432         else {
00433             if (avio_seek(s->pb, -8, SEEK_CUR) < 0 || avio_read(s->pb, oc->iv, 8) < 8) {
00434                 memset(oc->iv, 0, 8);
00435                 return -1;
00436             }
00437         }
00438     }
00439 
00440     return 0;
00441 }
00442 
00443 AVInputFormat ff_oma_demuxer = {
00444     .name           = "oma",
00445     .long_name      = NULL_IF_CONFIG_SMALL("Sony OpenMG audio"),
00446     .priv_data_size = sizeof(OMAContext),
00447     .read_probe     = oma_read_probe,
00448     .read_header    = oma_read_header,
00449     .read_packet    = oma_read_packet,
00450     .read_seek      = oma_read_seek,
00451     .flags          = AVFMT_GENERIC_INDEX,
00452     .extensions     = "oma,omg,aa3",
00453     .codec_tag      = (const AVCodecTag* const []){ff_oma_codec_tags, 0},
00454 };