FFmpeg: libavformat/oma.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 "pcm.h"
00048 #include "riff.h"
00049 #include "id3v2.h"
00050 
00051 #define EA3_HEADER_SIZE 96
00052 #define ID3v2_EA3_MAGIC "ea3"
00053 #define OMA_ENC_HEADER_SIZE 16
00054 
00055 enum {
00056     OMA_CODECID_ATRAC3  = 0,
00057     OMA_CODECID_ATRAC3P = 1,
00058     OMA_CODECID_MP3     = 3,
00059     OMA_CODECID_LPCM    = 4,
00060     OMA_CODECID_WMA     = 5,
00061 };
00062 
00063 static const AVCodecTag codec_oma_tags[] = {
00064     { CODEC_ID_ATRAC3,      OMA_CODECID_ATRAC3 },
00065     { CODEC_ID_ATRAC3P,     OMA_CODECID_ATRAC3P },
00066     { CODEC_ID_MP3,         OMA_CODECID_MP3 },
00067     { CODEC_ID_PCM_S16BE,   OMA_CODECID_LPCM },
00068 };
00069 
00070 static const uint64_t leaf_table[] = {
00071     0xd79e8283acea4620, 0x7a9762f445afd0d8,
00072     0x354d60a60b8c79f1, 0x584e1cde00b07aee,
00073     0x1573cd93da7df623, 0x47f98d79620dd535
00074 };
00075 
00076 typedef struct OMAContext {
00077     uint64_t content_start;
00078     int encrypted;
00079     uint16_t k_size;
00080     uint16_t e_size;
00081     uint16_t i_size;
00082     uint16_t s_size;
00083     uint32_t rid;
00084     uint8_t r_val[24];
00085     uint8_t n_val[24];
00086     uint8_t m_val[8];
00087     uint8_t s_val[8];
00088     uint8_t sm_val[8];
00089     uint8_t e_val[8];
00090     uint8_t iv[8];
00091     struct AVDES av_des;
00092 } OMAContext;
00093 
00094 static void hex_log(AVFormatContext *s, int level, const char *name, const uint8_t *value, int len)
00095 {
00096     char buf[33];
00097     len = FFMIN(len, 16);
00098     if (av_log_get_level() < level)
00099         return;
00100     ff_data_to_hex(buf, value, len, 1);
00101     buf[len<<1] = '\0';
00102     av_log(s, level, "%s: %s\n", name, buf);
00103 }
00104 
00105 static int kset(AVFormatContext *s, const uint8_t *r_val, const uint8_t *n_val, int len)
00106 {
00107     OMAContext *oc = s->priv_data;
00108 
00109     if (!r_val && !n_val)
00110         return -1;
00111 
00112     len = FFMIN(len, 16);
00113 
00114     /* use first 64 bits in the third round again */
00115     if (r_val) {
00116         if (r_val != oc->r_val) {
00117             memset(oc->r_val, 0, 24);
00118             memcpy(oc->r_val, r_val, len);
00119         }
00120         memcpy(&oc->r_val[16], r_val, 8);
00121     }
00122     if (n_val) {
00123         if (n_val != oc->n_val) {
00124             memset(oc->n_val, 0, 24);
00125             memcpy(oc->n_val, n_val, len);
00126         }
00127         memcpy(&oc->n_val[16], n_val, 8);
00128     }
00129 
00130     return 0;
00131 }
00132 
00133 static int rprobe(AVFormatContext *s, uint8_t *enc_header, const uint8_t *r_val)
00134 {
00135     OMAContext *oc = s->priv_data;
00136     unsigned int pos;
00137     struct AVDES av_des;
00138 
00139     if (!enc_header || !r_val)
00140         return -1;
00141 
00142     /* m_val */
00143     av_des_init(&av_des, r_val, 192, 1);
00144     av_des_crypt(&av_des, oc->m_val, &enc_header[48], 1, NULL, 1);
00145 
00146     /* s_val */
00147     av_des_init(&av_des, oc->m_val, 64, 0);
00148     av_des_crypt(&av_des, oc->s_val, NULL, 1, NULL, 0);
00149 
00150     /* sm_val */
00151     pos = OMA_ENC_HEADER_SIZE + oc->k_size + oc->e_size;
00152     av_des_init(&av_des, oc->s_val, 64, 0);
00153     av_des_mac(&av_des, oc->sm_val, &enc_header[pos], (oc->i_size >> 3));
00154 
00155     pos += oc->i_size;
00156 
00157     return memcmp(&enc_header[pos], oc->sm_val, 8) ? -1 : 0;
00158 }
00159 
00160 static int nprobe(AVFormatContext *s, uint8_t *enc_header, int size, const uint8_t *n_val)
00161 {
00162     OMAContext *oc = s->priv_data;
00163     uint32_t pos, taglen, datalen;
00164     struct AVDES av_des;
00165 
00166     if (!enc_header || !n_val)
00167         return -1;
00168 
00169     pos = OMA_ENC_HEADER_SIZE + oc->k_size;
00170     if (!memcmp(&enc_header[pos], "EKB ", 4))
00171         pos += 32;
00172 
00173     if (AV_RB32(&enc_header[pos]) != oc->rid)
00174         av_log(s, AV_LOG_DEBUG, "Mismatching RID\n");
00175 
00176     taglen = AV_RB32(&enc_header[pos+32]);
00177     datalen = AV_RB32(&enc_header[pos+36]) >> 4;
00178 
00179     if(taglen + (((uint64_t)datalen)<<4) + 44 > size)
00180         return -1;
00181 
00182     pos += 44 + taglen;
00183 
00184     av_des_init(&av_des, n_val, 192, 1);
00185     while (datalen-- > 0) {
00186         av_des_crypt(&av_des, oc->r_val, &enc_header[pos], 2, NULL, 1);
00187         kset(s, oc->r_val, NULL, 16);
00188         if (!rprobe(s, enc_header, oc->r_val))
00189             return 0;
00190         pos += 16;
00191     }
00192 
00193     return -1;
00194 }
00195 
00196 static int decrypt_init(AVFormatContext *s, ID3v2ExtraMeta *em, uint8_t *header)
00197 {
00198     OMAContext *oc = s->priv_data;
00199     ID3v2ExtraMetaGEOB *geob = NULL;
00200     uint8_t *gdata;
00201 
00202     oc->encrypted = 1;
00203     av_log(s, AV_LOG_INFO, "File is encrypted\n");
00204 
00205     /* find GEOB metadata */
00206     while (em) {
00207         if (!strcmp(em->tag, "GEOB") &&
00208             (geob = em->data) &&
00209             (!strcmp(geob->description, "OMG_LSI") ||
00210              !strcmp(geob->description, "OMG_BKLSI"))) {
00211             break;
00212         }
00213         em = em->next;
00214     }
00215     if (!em) {
00216         av_log(s, AV_LOG_ERROR, "No encryption header found\n");
00217         return -1;
00218     }
00219 
00220     if (geob->datasize < 64) {
00221         av_log(s, AV_LOG_ERROR, "Invalid GEOB data size: %u\n", geob->datasize);
00222         return -1;
00223     }
00224 
00225     gdata = geob->data;
00226 
00227     if (AV_RB16(gdata) != 1)
00228         av_log(s, AV_LOG_WARNING, "Unknown version in encryption header\n");
00229 
00230     oc->k_size = AV_RB16(&gdata[2]);
00231     oc->e_size = AV_RB16(&gdata[4]);
00232     oc->i_size = AV_RB16(&gdata[6]);
00233     oc->s_size = AV_RB16(&gdata[8]);
00234 
00235     if (memcmp(&gdata[OMA_ENC_HEADER_SIZE], "KEYRING     ", 12)) {
00236         av_log(s, AV_LOG_ERROR, "Invalid encryption header\n");
00237         return -1;
00238     }
00239     oc->rid = AV_RB32(&gdata[OMA_ENC_HEADER_SIZE + 28]);
00240     av_log(s, AV_LOG_DEBUG, "RID: %.8x\n", oc->rid);
00241 
00242     memcpy(oc->iv, &header[0x58], 8);
00243     hex_log(s, AV_LOG_DEBUG, "IV", oc->iv, 8);
00244 
00245     hex_log(s, AV_LOG_DEBUG, "CBC-MAC", &gdata[OMA_ENC_HEADER_SIZE+oc->k_size+oc->e_size+oc->i_size], 8);
00246 
00247     if (s->keylen > 0) {
00248         kset(s, s->key, s->key, s->keylen);
00249     }
00250     if (!memcmp(oc->r_val, (const uint8_t[8]){0}, 8) ||
00251         rprobe(s, gdata, oc->r_val) < 0 &&
00252         nprobe(s, gdata, geob->datasize, oc->n_val) < 0) {
00253         int i;
00254         for (i = 0; i < sizeof(leaf_table); i += 2) {
00255             uint8_t buf[16];
00256             AV_WL64(buf, leaf_table[i]);
00257             AV_WL64(&buf[8], leaf_table[i+1]);
00258             kset(s, buf, buf, 16);
00259             if (!rprobe(s, gdata, oc->r_val) || !nprobe(s, gdata, geob->datasize, oc->n_val))
00260                 break;
00261         }
00262         if (i >= sizeof(leaf_table)) {
00263             av_log(s, AV_LOG_ERROR, "Invalid key\n");
00264             return -1;
00265         }
00266     }
00267 
00268     /* e_val */
00269     av_des_init(&oc->av_des, oc->m_val, 64, 0);
00270     av_des_crypt(&oc->av_des, oc->e_val, &gdata[OMA_ENC_HEADER_SIZE + 40], 1, NULL, 0);
00271     hex_log(s, AV_LOG_DEBUG, "EK", oc->e_val, 8);
00272 
00273     /* init e_val */
00274     av_des_init(&oc->av_des, oc->e_val, 64, 1);
00275 
00276     return 0;
00277 }
00278 
00279 static int oma_read_header(AVFormatContext *s,
00280                            AVFormatParameters *ap)
00281 {
00282     static const uint16_t srate_tab[6] = {320,441,480,882,960,0};
00283     int     ret, framesize, jsflag, samplerate;
00284     uint32_t codec_params;
00285     int16_t eid;
00286     uint8_t buf[EA3_HEADER_SIZE];
00287     uint8_t *edata;
00288     AVStream *st;
00289     ID3v2ExtraMeta *extra_meta = NULL;
00290     OMAContext *oc = s->priv_data;
00291 
00292     ff_id3v2_read_all(s, ID3v2_EA3_MAGIC, &extra_meta);
00293     ret = avio_read(s->pb, buf, EA3_HEADER_SIZE);
00294     if (ret < EA3_HEADER_SIZE)
00295         return -1;
00296 
00297     if (memcmp(buf, ((const uint8_t[]){'E', 'A', '3'}),3) || buf[4] != 0 || buf[5] != EA3_HEADER_SIZE) {
00298         av_log(s, AV_LOG_ERROR, "Couldn't find the EA3 header !\n");
00299         return -1;
00300     }
00301 
00302     oc->content_start = avio_tell(s->pb);
00303 
00304     /* encrypted file */
00305     eid = AV_RB16(&buf[6]);
00306     if (eid != -1 && eid != -128 && decrypt_init(s, extra_meta, buf) < 0) {
00307         ff_id3v2_free_extra_meta(&extra_meta);
00308         return -1;
00309     }
00310 
00311     ff_id3v2_free_extra_meta(&extra_meta);
00312 
00313     codec_params = AV_RB24(&buf[33]);
00314 
00315     st = avformat_new_stream(s, NULL);
00316     if (!st)
00317         return AVERROR(ENOMEM);
00318 
00319     st->start_time = 0;
00320     st->codec->codec_type  = AVMEDIA_TYPE_AUDIO;
00321     st->codec->codec_tag   = buf[32];
00322     st->codec->codec_id    = ff_codec_get_id(codec_oma_tags, st->codec->codec_tag);
00323 
00324     switch (buf[32]) {
00325         case OMA_CODECID_ATRAC3:
00326             samplerate = srate_tab[(codec_params >> 13) & 7]*100;
00327             if (samplerate != 44100)
00328                 av_log_ask_for_sample(s, "Unsupported sample rate: %d\n",
00329                                       samplerate);
00330 
00331             framesize = (codec_params & 0x3FF) * 8;
00332             jsflag = (codec_params >> 17) & 1; /* get stereo coding mode, 1 for joint-stereo */
00333             st->codec->channels    = 2;
00334             st->codec->sample_rate = samplerate;
00335             st->codec->bit_rate    = st->codec->sample_rate * framesize * 8 / 1024;
00336 
00337             /* fake the atrac3 extradata (wav format, makes stream copy to wav work) */
00338             st->codec->extradata_size = 14;
00339             edata = av_mallocz(14 + FF_INPUT_BUFFER_PADDING_SIZE);
00340             if (!edata)
00341                 return AVERROR(ENOMEM);
00342 
00343             st->codec->extradata = edata;
00344             AV_WL16(&edata[0],  1);             // always 1
00345             AV_WL32(&edata[2],  samplerate);    // samples rate
00346             AV_WL16(&edata[6],  jsflag);        // coding mode
00347             AV_WL16(&edata[8],  jsflag);        // coding mode
00348             AV_WL16(&edata[10], 1);             // always 1
00349             // AV_WL16(&edata[12], 0);          // always 0
00350 
00351             avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
00352             break;
00353         case OMA_CODECID_ATRAC3P:
00354             st->codec->channels = (codec_params >> 10) & 7;
00355             framesize = ((codec_params & 0x3FF) * 8) + 8;
00356             st->codec->sample_rate = srate_tab[(codec_params >> 13) & 7]*100;
00357             st->codec->bit_rate    = st->codec->sample_rate * framesize * 8 / 1024;
00358             avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
00359             av_log(s, AV_LOG_ERROR, "Unsupported codec ATRAC3+!\n");
00360             break;
00361         case OMA_CODECID_MP3:
00362             st->need_parsing = AVSTREAM_PARSE_FULL;
00363             framesize = 1024;
00364             break;
00365         case OMA_CODECID_LPCM:
00366             /* PCM 44.1 kHz 16 bit stereo big-endian */
00367             st->codec->channels = 2;
00368             st->codec->sample_rate = 44100;
00369             framesize = 1024;
00370             /* bit rate = sample rate x PCM block align (= 4) x 8 */
00371             st->codec->bit_rate = st->codec->sample_rate * 32;
00372             st->codec->bits_per_coded_sample = av_get_bits_per_sample(st->codec->codec_id);
00373             avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
00374             break;
00375         default:
00376             av_log(s, AV_LOG_ERROR, "Unsupported codec %d!\n",buf[32]);
00377             return -1;
00378     }
00379 
00380     st->codec->block_align = framesize;
00381 
00382     return 0;
00383 }
00384 
00385 
00386 static int oma_read_packet(AVFormatContext *s, AVPacket *pkt)
00387 {
00388     OMAContext *oc = s->priv_data;
00389     int packet_size = s->streams[0]->codec->block_align;
00390     int ret = av_get_packet(s->pb, pkt, packet_size);
00391 
00392     if (ret <= 0)
00393         return AVERROR(EIO);
00394 
00395     pkt->stream_index = 0;
00396 
00397     if (oc->encrypted) {
00398         /* previous unencrypted block saved in IV for the next packet (CBC mode) */
00399         av_des_crypt(&oc->av_des, pkt->data, pkt->data, (packet_size >> 3), oc->iv, 1);
00400     }
00401 
00402     return ret;
00403 }
00404 
00405 static int oma_read_probe(AVProbeData *p)
00406 {
00407     const uint8_t *buf;
00408     unsigned tag_len = 0;
00409 
00410     buf = p->buf;
00411 
00412     if (p->buf_size < ID3v2_HEADER_SIZE ||
00413         !ff_id3v2_match(buf, ID3v2_EA3_MAGIC) ||
00414         buf[3] != 3 || // version must be 3
00415         buf[4]) // flags byte zero
00416         return 0;
00417 
00418     tag_len = ff_id3v2_tag_len(buf);
00419 
00420     /* This check cannot overflow as tag_len has at most 28 bits */
00421     if (p->buf_size < tag_len + 5)
00422         /* EA3 header comes late, might be outside of the probe buffer */
00423         return AVPROBE_SCORE_MAX / 2;
00424 
00425     buf += tag_len;
00426 
00427     if (!memcmp(buf, "EA3", 3) && !buf[4] && buf[5] == EA3_HEADER_SIZE)
00428         return AVPROBE_SCORE_MAX;
00429     else
00430         return 0;
00431 }
00432 
00433 static int oma_read_seek(struct AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
00434 {
00435     OMAContext *oc = s->priv_data;
00436 
00437     pcm_read_seek(s, stream_index, timestamp, flags);
00438 
00439     if (oc->encrypted) {
00440         /* readjust IV for CBC */
00441         int64_t pos = avio_tell(s->pb);
00442         if (pos < oc->content_start)
00443             memset(oc->iv, 0, 8);
00444         else {
00445             if (avio_seek(s->pb, -8, SEEK_CUR) < 0 || avio_read(s->pb, oc->iv, 8) < 8) {
00446                 memset(oc->iv, 0, 8);
00447                 return -1;
00448             }
00449         }
00450     }
00451 
00452     return 0;
00453 }
00454 
00455 AVInputFormat ff_oma_demuxer = {
00456     .name           = "oma",
00457     .long_name      = NULL_IF_CONFIG_SMALL("Sony OpenMG audio"),
00458     .priv_data_size = sizeof(OMAContext),
00459     .read_probe     = oma_read_probe,
00460     .read_header    = oma_read_header,
00461     .read_packet    = oma_read_packet,
00462     .read_seek      = oma_read_seek,
00463     .flags          = AVFMT_GENERIC_INDEX,
00464     .extensions     = "oma,omg,aa3",
00465     .codec_tag      = (const AVCodecTag* const []){codec_oma_tags, 0},
00466 };
00467