code.delx.au - pulseaudio/blob - src/modules/rtp/raop_client.c

   1 /* $Id$ */
   2
   3 /***
   4   This file is part of PulseAudio.
   5
   6   Copyright 2008 Colin Guthrie
   7
   8   PulseAudio is free software; you can redistribute it and/or modify
   9   it under the terms of the GNU Lesser General Public License as published
  10   by the Free Software Foundation; either version 2 of the License,
  11   or (at your option) any later version.
  12
  13   PulseAudio is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser General Public License
  19   along with PulseAudio; if not, write to the Free Software
  20   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  21   USA.
  22 ***/
  23
  24 #ifdef HAVE_CONFIG_H
  25 #include <config.h>
  26 #endif
  27
  28 #include <fcntl.h>
  29 #include <stdlib.h>
  30 #include <string.h>
  31 #include <errno.h>
  32 #include <arpa/inet.h>
  33 #include <unistd.h>
  34 #include <sys/ioctl.h>
  35
  36 #ifdef HAVE_SYS_FILIO_H
  37 #include <sys/filio.h>
  38 #endif
  39
  40 /* TODO: Replace OpenSSL with NSS */
  41 #include <openssl/err.h>
  42 #include <openssl/rand.h>
  43 #include <openssl/aes.h>
  44 #include <openssl/rsa.h>
  45 #include <openssl/engine.h>
  46
  47 #include <pulse/xmalloc.h>
  48
  49 #include <pulsecore/core-error.h>
  50 #include <pulsecore/core-util.h>
  51 #include <pulsecore/socket-util.h>
  52 #include <pulsecore/log.h>
  53 #include <pulsecore/macro.h>
  54 #include <pulsecore/strbuf.h>
  55 #include <pulsecore/random.h>
  56 #include <pulsecore/poll.h>
  57
  58 #include "raop_client.h"
  59 #include "rtsp_client.h"
  60 #include "base64.h"
  61
  62 #define AES_CHUNKSIZE 16
  63
  64 #define JACK_STATUS_DISCONNECTED 0
  65 #define JACK_STATUS_CONNECTED 1
  66
  67 #define JACK_TYPE_ANALOG 0
  68 #define JACK_TYPE_DIGITAL 1
  69
  70 #define VOLUME_DEF -30
  71 #define VOLUME_MIN -144
  72 #define VOLUME_MAX 0
  73
  74
  75 struct pa_raop_client {
  76     pa_mainloop_api *mainloop;
  77     const char *host;
  78     char *sid;
  79     pa_rtsp_client *rtsp;
  80
  81     uint8_t jack_type;
  82     uint8_t jack_status;
  83
  84     /* Encryption Related bits */
  85     AES_KEY aes;
  86     uint8_t aes_iv[AES_CHUNKSIZE]; /* initialization vector for aes-cbc */
  87     uint8_t aes_nv[AES_CHUNKSIZE]; /* next vector for aes-cbc */
  88     uint8_t aes_key[AES_CHUNKSIZE]; /* key for aes-cbc */
  89
  90     pa_socket_client *sc;
  91     int fd;
  92     pa_raop_client_cb_t callback;
  93     void* userdata;
  94
  95     uint8_t *buffer;
  96     uint8_t *buffer_index;
  97     uint16_t buffer_count;
  98     /*pa_memchunk memchunk;*/
  99 };
 100
 101 /**
 102  * Function to write bits into a buffer.
 103  * @param buffer Handle to the buffer. It will be incremented if new data requires it.
 104  * @param bit_pos A pointer to a position buffer to keep track the current write location (0 for MSB, 7 for LSB)
 105  * @param size A pointer to the byte size currently written. This allows the calling function to do simple buffer overflow checks
 106  * @param data The data to write
 107  * @param data_bit_len The number of bits from data to write
 108  */
 109 static inline void bit_writer(uint8_t **buffer, uint8_t *bit_pos, int *size, uint8_t data, uint8_t data_bit_len) {
 110     int bits_left, bit_overflow;
 111     uint8_t bit_data;
 112
 113     if (!data_bit_len)
 114         return;
 115
 116     /* If bit pos is zero, we will definatly use at least one bit from the current byte so size increments. */
 117     if (!*bit_pos)
 118         *size += 1;
 119
 120     /* Calc the number of bits left in the current byte of buffer */
 121     bits_left = 7 - *bit_pos  + 1;
 122     /* Calc the overflow of bits in relation to how much space we have left... */
 123     bit_overflow = bits_left - data_bit_len;
 124     if (bit_overflow >= 0) {
 125         /* We can fit the new data in our current byte */
 126         /* As we write from MSB->LSB we need to left shift by the overflow amount */
 127         bit_data = data << bit_overflow;
 128         if (*bit_pos)
 129             **buffer |= bit_data;
 130         else
 131             **buffer = bit_data;
 132         /* If our data fits exactly into the current byte, we need to increment our pointer */
 133         if (0 == bit_overflow) {
 134             /* Do not increment size as it will be incremeneted on next call as bit_pos is zero */
 135             *buffer += 1;
 136             *bit_pos = 0;
 137         } else {
 138             *bit_pos += data_bit_len;
 139         }
 140     } else {
 141         /* bit_overflow is negative, there for we will need a new byte from our buffer */
 142         /* Firstly fill up what's left in the current byte */
 143         bit_data = data >> -bit_overflow;
 144         **buffer |= bit_data;
 145         /* Increment our buffer pointer and size counter*/
 146         *buffer += 1;
 147         *size += 1;
 148         **buffer = data << (8 + bit_overflow);
 149         *bit_pos = -bit_overflow;
 150     }
 151 }
 152
 153 static int rsa_encrypt(uint8_t *text, int len, uint8_t *res) {
 154     char n[] =
 155         "59dE8qLieItsH1WgjrcFRKj6eUWqi+bGLOX1HL3U3GhC/j0Qg90u3sG/1CUtwC"
 156         "5vOYvfDmFI6oSFXi5ELabWJmT2dKHzBJKa3k9ok+8t9ucRqMd6DZHJ2YCCLlDR"
 157         "KSKv6kDqnw4UwPdpOMXziC/AMj3Z/lUVX1G7WSHCAWKf1zNS1eLvqr+boEjXuB"
 158         "OitnZ/bDzPHrTOZz0Dew0uowxf/+sG+NCK3eQJVxqcaJ/vEHKIVd2M+5qL71yJ"
 159         "Q+87X6oV3eaYvt3zWZYD6z5vYTcrtij2VZ9Zmni/UAaHqn9JdsBWLUEpVviYnh"
 160         "imNVvYFZeCXg/IdTQ+x4IRdiXNv5hEew==";
 161     char e[] = "AQAB";
 162     uint8_t modules[256];
 163     uint8_t exponent[8];
 164     int size;
 165     RSA *rsa;
 166
 167     rsa = RSA_new();
 168     size = pa_base64_decode(n, modules);
 169     rsa->n = BN_bin2bn(modules, size, NULL);
 170     size = pa_base64_decode(e, exponent);
 171     rsa->e = BN_bin2bn(exponent, size, NULL);
 172
 173     size = RSA_public_encrypt(len, text, res, rsa, RSA_PKCS1_OAEP_PADDING);
 174     RSA_free(rsa);
 175     return size;
 176 }
 177
 178 static int aes_encrypt(pa_raop_client* c, uint8_t *data, int size)
 179 {
 180     uint8_t *buf;
 181     int i=0, j;
 182
 183     pa_assert(c);
 184
 185     memcpy(c->aes_nv, c->aes_iv, AES_CHUNKSIZE);
 186     while (i+AES_CHUNKSIZE <= size) {
 187         buf = data + i;
 188         for (j=0; j<AES_CHUNKSIZE; ++j)
 189             buf[j] ^= c->aes_nv[j];
 190
 191         AES_encrypt(buf, buf, &c->aes);
 192         memcpy(c->aes_nv, buf, AES_CHUNKSIZE);
 193         i += AES_CHUNKSIZE;
 194     }
 195     return i;
 196 }
 197
 198 static inline void rtrimchar(char *str, char rc)
 199 {
 200     char *sp = str + strlen(str) - 1;
 201     while (sp >= str && *sp == rc) {
 202         *sp = '\0';
 203         sp -= 1;
 204     }
 205 }
 206
 207 static void on_connection(pa_socket_client *sc, pa_iochannel *io, void *userdata) {
 208     pa_raop_client *c = userdata;
 209
 210     pa_assert(sc);
 211     pa_assert(c);
 212     pa_assert(c->sc == sc);
 213     pa_assert(c->fd < 0);
 214     pa_assert(c->callback);
 215
 216     pa_socket_client_unref(c->sc);
 217     c->sc = NULL;
 218
 219     if (!io) {
 220         pa_log("Connection failed: %s", pa_cstrerror(errno));
 221         return;
 222     }
 223
 224     c->fd = pa_iochannel_get_send_fd(io);
 225
 226     pa_iochannel_set_noclose(io, TRUE);
 227     pa_iochannel_free(io);
 228
 229     pa_make_tcp_socket_low_delay(c->fd);
 230
 231     pa_log_debug("Connection established");
 232     c->callback(c->fd, c->userdata);
 233 }
 234
 235 static void rtsp_cb(pa_rtsp_client *rtsp, pa_rtsp_state state, pa_headerlist* headers, void *userdata)
 236 {
 237     pa_raop_client* c = userdata;
 238     pa_assert(c);
 239     pa_assert(rtsp);
 240     pa_assert(rtsp == c->rtsp);
 241
 242     switch (state) {
 243         case STATE_CONNECT: {
 244             int i;
 245             uint8_t rsakey[512];
 246             char *key, *iv, *sac, *sdp;
 247             uint16_t rand_data;
 248             const char *ip;
 249             char *url;
 250
 251             pa_log_debug("RAOP: CONNECTED");
 252             ip = pa_rtsp_localip(c->rtsp);
 253             /* First of all set the url properly */
 254             url = pa_sprintf_malloc("rtsp://%s/%s", ip, c->sid);
 255             pa_rtsp_set_url(c->rtsp, url);
 256             pa_xfree(url);
 257
 258             /* Now encrypt our aes_public key to send to the device */
 259             i = rsa_encrypt(c->aes_key, AES_CHUNKSIZE, rsakey);
 260             pa_base64_encode(rsakey, i, &key);
 261             rtrimchar(key, '=');
 262             pa_base64_encode(c->aes_iv, AES_CHUNKSIZE, &iv);
 263             rtrimchar(iv, '=');
 264
 265             pa_random(&rand_data, sizeof(rand_data));
 266             pa_base64_encode(&rand_data, AES_CHUNKSIZE, &sac);
 267             rtrimchar(sac, '=');
 268             pa_rtsp_add_header(c->rtsp, "Apple-Challenge", sac);
 269             sdp = pa_sprintf_malloc(
 270                 "v=0\r\n"
 271                 "o=iTunes %s 0 IN IP4 %s\r\n"
 272                 "s=iTunes\r\n"
 273                 "c=IN IP4 %s\r\n"
 274                 "t=0 0\r\n"
 275                 "m=audio 0 RTP/AVP 96\r\n"
 276                 "a=rtpmap:96 AppleLossless\r\n"
 277                 "a=fmtp:96 4096 0 16 40 10 14 2 255 0 0 44100\r\n"
 278                 "a=rsaaeskey:%s\r\n"
 279                 "a=aesiv:%s\r\n",
 280                 c->sid, ip, c->host, key, iv);
 281             pa_rtsp_announce(c->rtsp, sdp);
 282             pa_xfree(key);
 283             pa_xfree(iv);
 284             pa_xfree(sac);
 285             pa_xfree(sdp);
 286             break;
 287         }
 288
 289         case STATE_ANNOUNCE:
 290             pa_log_debug("RAOP: ANNOUNCED");
 291             pa_rtsp_remove_header(c->rtsp, "Apple-Challenge");
 292             pa_rtsp_setup(c->rtsp);
 293             break;
 294
 295         case STATE_SETUP: {
 296             char *aj = pa_xstrdup(pa_headerlist_gets(headers, "Audio-Jack-Status"));
 297             pa_log_debug("RAOP: SETUP");
 298             if (aj) {
 299                 char *token, *pc;
 300                 char delimiters[] = ";";
 301                 const char* token_state = NULL;
 302                 c->jack_type = JACK_TYPE_ANALOG;
 303                 c->jack_status = JACK_STATUS_DISCONNECTED;
 304
 305                 while ((token = pa_split(aj, delimiters, &token_state))) {
 306                     if ((pc = strstr(token, "="))) {
 307                       *pc = 0;
 308                       if (!strcmp(token, "type") && !strcmp(pc+1, "digital")) {
 309                           c->jack_type = JACK_TYPE_DIGITAL;
 310                       }
 311                     } else {
 312                         if (!strcmp(token,"connected"))
 313                             c->jack_status = JACK_STATUS_CONNECTED;
 314                     }
 315                     pa_xfree(token);
 316                 }
 317                 pa_xfree(aj);
 318             } else {
 319                 pa_log_warn("Audio Jack Status missing");
 320             }
 321             pa_rtsp_record(c->rtsp);
 322             break;
 323         }
 324
 325         case STATE_RECORD: {
 326             uint32_t port = pa_rtsp_serverport(c->rtsp);
 327             pa_log_debug("RAOP: RECORDED");
 328
 329             if (!(c->sc = pa_socket_client_new_string(c->mainloop, c->host, port))) {
 330                 pa_log("failed to connect to server '%s:%d'", c->host, port);
 331                 return;
 332             }
 333             pa_socket_client_set_callback(c->sc, on_connection, c);
 334             break;
 335         }
 336
 337         case STATE_TEARDOWN:
 338         case STATE_SET_PARAMETER:
 339         case STATE_FLUSH:
 340             break;
 341     }
 342 }
 343
 344 pa_raop_client* pa_raop_client_new(pa_mainloop_api *mainloop, const char* host)
 345 {
 346     char *sci;
 347     struct {
 348         uint32_t a;
 349         uint32_t b;
 350         uint32_t c;
 351     } rand_data;
 352     pa_raop_client* c = pa_xnew0(pa_raop_client, 1);
 353
 354     pa_assert(host);
 355
 356     c->mainloop = mainloop;
 357     c->fd = -1;
 358     c->host = pa_xstrdup(host);
 359     c->rtsp = pa_rtsp_client_new("iTunes/4.6 (Macintosh; U; PPC Mac OS X 10.3)");
 360
 361     /* Initialise the AES encryption system */
 362     pa_random_seed();
 363     pa_random(c->aes_iv, sizeof(c->aes_iv));
 364     pa_random(c->aes_key, sizeof(c->aes_key));
 365     memcpy(c->aes_nv, c->aes_iv, sizeof(c->aes_nv));
 366     AES_set_encrypt_key(c->aes_key, 128, &c->aes);
 367
 368     /* Generate random instance id */
 369     pa_random(&rand_data, sizeof(rand_data));
 370     c->sid = pa_sprintf_malloc("%u", rand_data.a);
 371     sci = pa_sprintf_malloc("%08x%08x",rand_data.b, rand_data.c);
 372     pa_rtsp_add_header(c->rtsp, "Client-Instance", sci);
 373     pa_rtsp_set_callback(c->rtsp, rtsp_cb, c);
 374     if (pa_rtsp_connect(c->rtsp, mainloop, host, 5000)) {
 375         pa_rtsp_client_free(c->rtsp);
 376         pa_xfree(c->aes_iv);
 377         pa_xfree(c->aes_nv);
 378         pa_xfree(c->aes_key);
 379         return NULL;
 380     }
 381     return c;
 382 }
 383
 384
 385 void pa_raop_client_free(pa_raop_client* c)
 386 {
 387     pa_assert(c);
 388
 389     pa_rtsp_client_free(c->rtsp);
 390     pa_xfree(c->aes_iv);
 391     pa_xfree(c->aes_nv);
 392     pa_xfree(c->aes_key);
 393     pa_xfree(c->host);
 394     pa_xfree(c);
 395 }
 396
 397
 398 static void noop(PA_GCC_UNUSED void* p) {}
 399
 400 pa_memchunk pa_raop_client_encode_sample(pa_raop_client* c, pa_mempool* mempool, pa_memchunk* raw)
 401 {
 402     uint16_t len, bufmax;
 403     uint8_t *bp, bpos;
 404     uint8_t *ibp, *maxibp;
 405     int size;
 406     uint8_t *p;
 407     uint16_t bsize;
 408     pa_memchunk rv;
 409     size_t length;
 410     static uint8_t header[] = {
 411         0x24, 0x00, 0x00, 0x00,
 412         0xF0, 0xFF, 0x00, 0x00,
 413         0x00, 0x00, 0x00, 0x00,
 414         0x00, 0x00, 0x00, 0x00,
 415     };
 416     const int header_size = sizeof(header);
 417
 418     pa_assert(c);
 419     pa_assert(c->fd > 0);
 420     pa_assert(raw);
 421     pa_assert(raw->memblock);
 422     pa_assert(raw->length > 0);
 423
 424     /* We have to send 4 byte chunks */
 425     bsize = (int)(raw->length / 4);
 426     length = bsize * 4;
 427
 428     /* Leave 16 bytes extra to allow for the ALAC header which is about 55 bits */
 429     bufmax = length + header_size + 16;
 430     c->buffer = pa_xrealloc(c->buffer, bufmax);
 431     memcpy(c->buffer, header, header_size);
 432     pa_memchunk_reset(&rv);
 433     rv.memblock = pa_memblock_new_user(mempool, c->buffer, (header_size + length), noop, 1);
 434
 435     /* Now write the actual samples */
 436     bp = c->buffer + header_size;
 437     size = bpos = 0;
 438     bit_writer(&bp,&bpos,&size,1,3); // channel=1, stereo
 439     bit_writer(&bp,&bpos,&size,0,4); // unknown
 440     bit_writer(&bp,&bpos,&size,0,8); // unknown
 441     bit_writer(&bp,&bpos,&size,0,4); // unknown
 442     bit_writer(&bp,&bpos,&size,1,1); // hassize
 443     bit_writer(&bp,&bpos,&size,0,2); // unused
 444     bit_writer(&bp,&bpos,&size,1,1); // is-not-compressed
 445
 446     /* size of data, integer, big endian */
 447     bit_writer(&bp,&bpos,&size,(bsize>>24)&0xff,8);
 448     bit_writer(&bp,&bpos,&size,(bsize>>16)&0xff,8);
 449     bit_writer(&bp,&bpos,&size,(bsize>>8)&0xff,8);
 450     bit_writer(&bp,&bpos,&size,(bsize)&0xff,8);
 451
 452     ibp = p = pa_memblock_acquire(raw->memblock);
 453     maxibp = p + raw->length - 4;
 454     while (ibp <= maxibp) {
 455         /* Byte swap stereo data */
 456         bit_writer(&bp,&bpos,&size,*(ibp+1),8);
 457         bit_writer(&bp,&bpos,&size,*(ibp+0),8);
 458         bit_writer(&bp,&bpos,&size,*(ibp+3),8);
 459         bit_writer(&bp,&bpos,&size,*(ibp+2),8);
 460         ibp += 4;
 461         raw->index += 4;
 462         raw->length -= 4;
 463     }
 464     pa_memblock_release(raw->memblock);
 465     rv.length = header_size + size;
 466
 467     /* store the lenght (endian swapped: make this better) */
 468     len = size + header_size - 4;
 469     *(c->buffer + 2) = len >> 8;
 470     *(c->buffer + 3) = len & 0xff;
 471
 472     /* encrypt our data */
 473     aes_encrypt(c, (c->buffer + header_size), size);
 474     return rv;
 475 }
 476
 477
 478 void pa_raop_client_set_callback(pa_raop_client* c, pa_raop_client_cb_t callback, void *userdata)
 479 {
 480     pa_assert(c);
 481
 482     c->callback = callback;
 483     c->userdata = userdata;
 484 }