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 
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 "riff.h"
00050 #include "id3v2.h"
00051 
00052 
00053 static const uint64_t leaf_table[] = {
00054     0xd79e8283acea4620, 0x7a9762f445afd0d8,
00055     0x354d60a60b8c79f1, 0x584e1cde00b07aee,
00056     0x1573cd93da7df623, 0x47f98d79620dd535
00057 };
00058 
00059 typedef struct OMAContext {
00060     uint64_t content_start;
00061     int encrypted;
00062     uint16_t k_size;
00063     uint16_t e_size;
00064     uint16_t i_size;
00065     uint16_t s_size;
00066     uint32_t rid;
00067     uint8_t r_val[24];
00068     uint8_t n_val[24];
00069     uint8_t m_val[8];
00070     uint8_t s_val[8];
00071     uint8_t sm_val[8];
00072     uint8_t e_val[8];
00073     uint8_t iv[8];
00074     struct AVDES av_des;
00075 } OMAContext;
00076 
00077 static void hex_log(AVFormatContext *s, int level, const char *name, const uint8_t *value, int len)
00078 {
00079     char buf[33];
00080     len = FFMIN(len, 16);
00081     if (av_log_get_level() < level)
00082         return;
00083     ff_data_to_hex(buf, value, len, 1);
00084     buf[len<<1] = '\0';
00085     av_log(s, level, "%s: %s\n", name, buf);
00086 }
00087 
00088 static int kset(AVFormatContext *s, const uint8_t *r_val, const uint8_t *n_val, int len)
00089 {
00090     OMAContext *oc = s->priv_data;
00091 
00092     if (!r_val && !n_val)
00093         return -1;
00094 
00095     len = FFMIN(len, 16);
00096 
00097     /* use first 64 bits in the third round again */
00098     if (r_val) {
00099         if (r_val != oc->r_val) {
00100             memset(oc->r_val, 0, 24);
00101             memcpy(oc->r_val, r_val, len);
00102         }
00103         memcpy(&oc->r_val[16], r_val, 8);
00104     }
00105     if (n_val) {
00106         if (n_val != oc->n_val) {
00107             memset(oc->n_val, 0, 24);
00108             memcpy(oc->n_val, n_val, len);
00109         }
00110         memcpy(&oc->n_val[16], n_val, 8);
00111     }
00112 
00113     return 0;
00114 }
00115 
00116 static int rprobe(AVFormatContext *s, uint8_t *enc_header, const uint8_t *r_val)
00117 {
00118     OMAContext *oc = s->priv_data;
00119     unsigned int pos;
00120     struct AVDES av_des;
00121 
00122     if (!enc_header || !r_val)
00123         return -1;
00124 
00125     /* m_val */
00126     av_des_init(&av_des, r_val, 192, 1);
00127     av_des_crypt(&av_des, oc->m_val, &enc_header[48], 1, NULL, 1);
00128 
00129     /* s_val */
00130     av_des_init(&av_des, oc->m_val, 64, 0);
00131     av_des_crypt(&av_des, oc->s_val, NULL, 1, NULL, 0);
00132 
00133     /* sm_val */
00134     pos = OMA_ENC_HEADER_SIZE + oc->k_size + oc->e_size;
00135     av_des_init(&av_des, oc->s_val, 64, 0);
00136     av_des_mac(&av_des, oc->sm_val, &enc_header[pos], (oc->i_size >> 3));
00137 
00138     pos += oc->i_size;
00139 
00140     return memcmp(&enc_header[pos], oc->sm_val, 8) ? -1 : 0;
00141 }
00142 
00143 static int nprobe(AVFormatContext *s, uint8_t *enc_header, int size, const uint8_t *n_val)
00144 {
00145     OMAContext *oc = s->priv_data;
00146     uint32_t pos, taglen, datalen;
00147     struct AVDES av_des;
00148 
00149     if (!enc_header || !n_val)
00150         return -1;
00151 
00152     pos = OMA_ENC_HEADER_SIZE + oc->k_size;
00153     if (!memcmp(&enc_header[pos], "EKB ", 4))
00154         pos += 32;
00155 
00156     if (AV_RB32(&enc_header[pos]) != oc->rid)
00157         av_log(s, AV_LOG_DEBUG, "Mismatching RID\n");
00158 
00159     taglen = AV_RB32(&enc_header[pos+32]);
00160     datalen = AV_RB32(&enc_header[pos+36]) >> 4;
00161 
00162     if(taglen + (((uint64_t)datalen)<<4) + 44 > size)
00163         return -1;
00164 
00165     pos += 44 + taglen;
00166 
00167     av_des_init(&av_des, n_val, 192, 1);
00168     while (datalen-- > 0) {
00169         av_des_crypt(&av_des, oc->r_val, &enc_header[pos], 2, NULL, 1);
00170         kset(s, oc->r_val, NULL, 16);
00171         if (!rprobe(s, enc_header, oc->r_val))
00172             return 0;
00173         pos += 16;
00174     }
00175 
00176     return -1;
00177 }
00178 
00179 static int decrypt_init(AVFormatContext *s, ID3v2ExtraMeta *em, uint8_t *header)
00180 {
00181     OMAContext *oc = s->priv_data;
00182     ID3v2ExtraMetaGEOB *geob = NULL;
00183     uint8_t *gdata;
00184 
00185     oc->encrypted = 1;
00186     av_log(s, AV_LOG_INFO, "File is encrypted\n");
00187 
00188     /* find GEOB metadata */
00189     while (em) {
00190         if (!strcmp(em->tag, "GEOB") &&
00191             (geob = em->data) &&
00192             (!strcmp(geob->description, "OMG_LSI") ||
00193              !strcmp(geob->description, "OMG_BKLSI"))) {
00194             break;
00195         }
00196         em = em->next;
00197     }
00198     if (!em) {
00199         av_log(s, AV_LOG_ERROR, "No encryption header found\n");
00200         return -1;
00201     }
00202 
00203     if (geob->datasize < 64) {
00204         av_log(s, AV_LOG_ERROR, "Invalid GEOB data size: %u\n", geob->datasize);
00205         return -1;
00206     }
00207 
00208     gdata = geob->data;
00209 
00210     if (AV_RB16(gdata) != 1)
00211         av_log(s, AV_LOG_WARNING, "Unknown version in encryption header\n");
00212 
00213     oc->k_size = AV_RB16(&gdata[2]);
00214     oc->e_size = AV_RB16(&gdata[4]);
00215     oc->i_size = AV_RB16(&gdata[6]);
00216     oc->s_size = AV_RB16(&gdata[8]);
00217 
00218     if (memcmp(&gdata[OMA_ENC_HEADER_SIZE], "KEYRING     ", 12)) {
00219         av_log(s, AV_LOG_ERROR, "Invalid encryption header\n");
00220         return -1;
00221     }
00222     if (   OMA_ENC_HEADER_SIZE + oc->k_size + oc->e_size + oc->i_size + 8 > geob->datasize
00223         || OMA_ENC_HEADER_SIZE + 48 > geob->datasize
00224     ) {
00225         av_log(s, AV_LOG_ERROR, "Too little GEOB data\n");
00226         return AVERROR_INVALIDDATA;
00227     }
00228     oc->rid = AV_RB32(&gdata[OMA_ENC_HEADER_SIZE + 28]);
00229     av_log(s, AV_LOG_DEBUG, "RID: %.8x\n", oc->rid);
00230 
00231     memcpy(oc->iv, &header[0x58], 8);
00232     hex_log(s, AV_LOG_DEBUG, "IV", oc->iv, 8);
00233 
00234     hex_log(s, AV_LOG_DEBUG, "CBC-MAC", &gdata[OMA_ENC_HEADER_SIZE+oc->k_size+oc->e_size+oc->i_size], 8);
00235 
00236     if (s->keylen > 0) {
00237         kset(s, s->key, s->key, s->keylen);
00238     }
00239     if (!memcmp(oc->r_val, (const uint8_t[8]){0}, 8) ||
00240         rprobe(s, gdata, oc->r_val) < 0 &&
00241         nprobe(s, gdata, geob->datasize, oc->n_val) < 0) {
00242         int i;
00243         for (i = 0; i < FF_ARRAY_ELEMS(leaf_table); i += 2) {
00244             uint8_t buf[16];
00245             AV_WL64(buf, leaf_table[i]);
00246             AV_WL64(&buf[8], leaf_table[i+1]);
00247             kset(s, buf, buf, 16);
00248             if (!rprobe(s, gdata, oc->r_val) || !nprobe(s, gdata, geob->datasize, oc->n_val))
00249                 break;
00250         }
00251         if (i >= FF_ARRAY_ELEMS(leaf_table)) {
00252             av_log(s, AV_LOG_ERROR, "Invalid key\n");
00253             return -1;
00254         }
00255     }
00256 
00257     /* e_val */
00258     av_des_init(&oc->av_des, oc->m_val, 64, 0);
00259     av_des_crypt(&oc->av_des, oc->e_val, &gdata[OMA_ENC_HEADER_SIZE + 40], 1, NULL, 0);
00260     hex_log(s, AV_LOG_DEBUG, "EK", oc->e_val, 8);
00261 
00262     /* init e_val */
00263     av_des_init(&oc->av_des, oc->e_val, 64, 1);
00264 
00265     return 0;
00266 }
00267 
00268 static int oma_read_header(AVFormatContext *s)
00269 {
00270     int     ret, framesize, jsflag, samplerate;
00271     uint32_t codec_params;
00272     int16_t eid;
00273     uint8_t buf[EA3_HEADER_SIZE];
00274     uint8_t *edata;
00275     AVStream *st;
00276     ID3v2ExtraMeta *extra_meta = NULL;
00277     OMAContext *oc = s->priv_data;
00278 
00279     ff_id3v2_read(s, ID3v2_EA3_MAGIC, &extra_meta);
00280     ret = avio_read(s->pb, buf, EA3_HEADER_SIZE);
00281     if (ret < EA3_HEADER_SIZE)
00282         return -1;
00283 
00284     if (memcmp(buf, ((const uint8_t[]){'E', 'A', '3'}),3) || buf[4] != 0 || buf[5] != EA3_HEADER_SIZE) {
00285         av_log(s, AV_LOG_ERROR, "Couldn't find the EA3 header !\n");
00286         return -1;
00287     }
00288 
00289     oc->content_start = avio_tell(s->pb);
00290 
00291     /* encrypted file */
00292     eid = AV_RB16(&buf[6]);
00293     if (eid != -1 && eid != -128 && decrypt_init(s, extra_meta, buf) < 0) {
00294         ff_id3v2_free_extra_meta(&extra_meta);
00295         return -1;
00296     }
00297 
00298     ff_id3v2_free_extra_meta(&extra_meta);
00299 
00300     codec_params = AV_RB24(&buf[33]);
00301 
00302     st = avformat_new_stream(s, NULL);
00303     if (!st)
00304         return AVERROR(ENOMEM);
00305 
00306     st->start_time = 0;
00307     st->codec->codec_type  = AVMEDIA_TYPE_AUDIO;
00308     st->codec->codec_tag   = buf[32];
00309     st->codec->codec_id    = ff_codec_get_id(ff_oma_codec_tags, st->codec->codec_tag);
00310 
00311     switch (buf[32]) {
00312         case OMA_CODECID_ATRAC3:
00313             samplerate = ff_oma_srate_tab[(codec_params >> 13) & 7]*100;
00314             if (samplerate != 44100)
00315                 av_log_ask_for_sample(s, "Unsupported sample rate: %d\n",
00316                                       samplerate);
00317 
00318             framesize = (codec_params & 0x3FF) * 8;
00319             jsflag = (codec_params >> 17) & 1; /* get stereo coding mode, 1 for joint-stereo */
00320             st->codec->channels    = 2;
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;
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->sample_rate = 44100;
00356             framesize = 1024;
00357             /* bit rate = sample rate x PCM block align (= 4) x 8 */
00358             st->codec->bit_rate = st->codec->sample_rate * 32;
00359             st->codec->bits_per_coded_sample = av_get_bits_per_sample(st->codec->codec_id);
00360             avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
00361             break;
00362         default:
00363             av_log(s, AV_LOG_ERROR, "Unsupported codec %d!\n",buf[32]);
00364             return -1;
00365     }
00366 
00367     st->codec->block_align = framesize;
00368 
00369     return 0;
00370 }
00371 
00372 
00373 static int oma_read_packet(AVFormatContext *s, AVPacket *pkt)
00374 {
00375     OMAContext *oc = s->priv_data;
00376     int packet_size = s->streams[0]->codec->block_align;
00377     int ret = av_get_packet(s->pb, pkt, packet_size);
00378 
00379     if (ret <= 0)
00380         return AVERROR(EIO);
00381 
00382     pkt->stream_index = 0;
00383 
00384     if (oc->encrypted) {
00385         /* previous unencrypted block saved in IV for the next packet (CBC mode) */
00386         av_des_crypt(&oc->av_des, pkt->data, pkt->data, (ret >> 3), oc->iv, 1);
00387     }
00388 
00389     return ret;
00390 }
00391 
00392 static int oma_read_probe(AVProbeData *p)
00393 {
00394     const uint8_t *buf;
00395     unsigned tag_len = 0;
00396 
00397     buf = p->buf;
00398 
00399     if (p->buf_size < ID3v2_HEADER_SIZE ||
00400         !ff_id3v2_match(buf, ID3v2_EA3_MAGIC) ||
00401         buf[3] != 3 || // version must be 3
00402         buf[4]) // flags byte zero
00403         return 0;
00404 
00405     tag_len = ff_id3v2_tag_len(buf);
00406 
00407     /* This check cannot overflow as tag_len has at most 28 bits */
00408     if (p->buf_size < tag_len + 5)
00409         /* EA3 header comes late, might be outside of the probe buffer */
00410         return AVPROBE_SCORE_MAX / 2;
00411 
00412     buf += tag_len;
00413 
00414     if (!memcmp(buf, "EA3", 3) && !buf[4] && buf[5] == EA3_HEADER_SIZE)
00415         return AVPROBE_SCORE_MAX;
00416     else
00417         return 0;
00418 }
00419 
00420 static int oma_read_seek(struct AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
00421 {
00422     OMAContext *oc = s->priv_data;
00423 
00424     ff_pcm_read_seek(s, stream_index, timestamp, flags);
00425 
00426     if (oc->encrypted) {
00427         /* readjust IV for CBC */
00428         int64_t pos = avio_tell(s->pb);
00429         if (pos < oc->content_start)
00430             memset(oc->iv, 0, 8);
00431         else {
00432             if (avio_seek(s->pb, -8, SEEK_CUR) < 0 || avio_read(s->pb, oc->iv, 8) < 8) {
00433                 memset(oc->iv, 0, 8);
00434                 return -1;
00435             }
00436         }
00437     }
00438 
00439     return 0;
00440 }
00441 
00442 AVInputFormat ff_oma_demuxer = {
00443     .name           = "oma",
00444     .long_name      = NULL_IF_CONFIG_SMALL("Sony OpenMG audio"),
00445     .priv_data_size = sizeof(OMAContext),
00446     .read_probe     = oma_read_probe,
00447     .read_header    = oma_read_header,
00448     .read_packet    = oma_read_packet,
00449     .read_seek      = oma_read_seek,
00450     .flags          = AVFMT_GENERIC_INDEX,
00451     .extensions     = "oma,omg,aa3",
00452     .codec_tag      = (const AVCodecTag* const []){ff_oma_codec_tags, 0},
00453 };