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_core *core;
  77     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
  93     pa_raop_client_cb_t callback;
  94     void* userdata;
  95     pa_raop_client_closed_cb_t closed_callback;
  96     void* closed_userdata;
  97
  98     uint8_t *buffer;
  99     size_t buffer_length;
 100     uint8_t *buffer_index;
 101     uint16_t buffer_count;
 102 };
 103
 104 /**
 105  * Function to write bits into a buffer.
 106  * @param buffer Handle to the buffer. It will be incremented if new data requires it.
 107  * @param bit_pos A pointer to a position buffer to keep track the current write location (0 for MSB, 7 for LSB)
 108  * @param size A pointer to the byte size currently written. This allows the calling function to do simple buffer overflow checks
 109  * @param data The data to write
 110  * @param data_bit_len The number of bits from data to write
 111  */
 112 static inline void bit_writer(uint8_t **buffer, uint8_t *bit_pos, int *size, uint8_t data, uint8_t data_bit_len) {
 113     int bits_left, bit_overflow;
 114     uint8_t bit_data;
 115
 116     if (!data_bit_len)
 117         return;
 118
 119     /* If bit pos is zero, we will definatly use at least one bit from the current byte so size increments. */
 120     if (!*bit_pos)
 121         *size += 1;
 122
 123     /* Calc the number of bits left in the current byte of buffer */
 124     bits_left = 7 - *bit_pos  + 1;
 125     /* Calc the overflow of bits in relation to how much space we have left... */
 126     bit_overflow = bits_left - data_bit_len;
 127     if (bit_overflow >= 0) {
 128         /* We can fit the new data in our current byte */
 129         /* As we write from MSB->LSB we need to left shift by the overflow amount */
 130         bit_data = data << bit_overflow;
 131         if (*bit_pos)
 132             **buffer |= bit_data;
 133         else
 134             **buffer = bit_data;
 135         /* If our data fits exactly into the current byte, we need to increment our pointer */
 136         if (0 == bit_overflow) {
 137             /* Do not increment size as it will be incremeneted on next call as bit_pos is zero */
 138             *buffer += 1;
 139             *bit_pos = 0;
 140         } else {
 141             *bit_pos += data_bit_len;
 142         }
 143     } else {
 144         /* bit_overflow is negative, there for we will need a new byte from our buffer */
 145         /* Firstly fill up what's left in the current byte */
 146         bit_data = data >> -bit_overflow;
 147         **buffer |= bit_data;
 148         /* Increment our buffer pointer and size counter*/
 149         *buffer += 1;
 150         *size += 1;
 151         **buffer = data << (8 + bit_overflow);
 152         *bit_pos = -bit_overflow;
 153     }
 154 }
 155
 156 static int rsa_encrypt(uint8_t *text, int len, uint8_t *res) {
 157     const char n[] =
 158         "59dE8qLieItsH1WgjrcFRKj6eUWqi+bGLOX1HL3U3GhC/j0Qg90u3sG/1CUtwC"
 159         "5vOYvfDmFI6oSFXi5ELabWJmT2dKHzBJKa3k9ok+8t9ucRqMd6DZHJ2YCCLlDR"
 160         "KSKv6kDqnw4UwPdpOMXziC/AMj3Z/lUVX1G7WSHCAWKf1zNS1eLvqr+boEjXuB"
 161         "OitnZ/bDzPHrTOZz0Dew0uowxf/+sG+NCK3eQJVxqcaJ/vEHKIVd2M+5qL71yJ"
 162         "Q+87X6oV3eaYvt3zWZYD6z5vYTcrtij2VZ9Zmni/UAaHqn9JdsBWLUEpVviYnh"
 163         "imNVvYFZeCXg/IdTQ+x4IRdiXNv5hEew==";
 164     const char e[] = "AQAB";
 165     uint8_t modules[256];
 166     uint8_t exponent[8];
 167     int size;
 168     RSA *rsa;
 169
 170     rsa = RSA_new();
 171     size = pa_base64_decode(n, modules);
 172     rsa->n = BN_bin2bn(modules, size, NULL);
 173     size = pa_base64_decode(e, exponent);
 174     rsa->e = BN_bin2bn(exponent, size, NULL);
 175
 176     size = RSA_public_encrypt(len, text, res, rsa, RSA_PKCS1_OAEP_PADDING);
 177     RSA_free(rsa);
 178     return size;
 179 }
 180
 181 static int aes_encrypt(pa_raop_client* c, uint8_t *data, int size)
 182 {
 183     uint8_t *buf;
 184     int i=0, j;
 185
 186     pa_assert(c);
 187
 188     memcpy(c->aes_nv, c->aes_iv, AES_CHUNKSIZE);
 189     while (i+AES_CHUNKSIZE <= size) {
 190         buf = data + i;
 191         for (j=0; j<AES_CHUNKSIZE; ++j)
 192             buf[j] ^= c->aes_nv[j];
 193
 194         AES_encrypt(buf, buf, &c->aes);
 195         memcpy(c->aes_nv, buf, AES_CHUNKSIZE);
 196         i += AES_CHUNKSIZE;
 197     }
 198     return i;
 199 }
 200
 201 static inline void rtrimchar(char *str, char rc)
 202 {
 203     char *sp = str + strlen(str) - 1;
 204     while (sp >= str && *sp == rc) {
 205         *sp = '\0';
 206         sp -= 1;
 207     }
 208 }
 209
 210 static void on_connection(pa_socket_client *sc, pa_iochannel *io, void *userdata) {
 211     pa_raop_client *c = userdata;
 212
 213     pa_assert(sc);
 214     pa_assert(c);
 215     pa_assert(c->sc == sc);
 216     pa_assert(c->fd < 0);
 217     pa_assert(c->callback);
 218
 219     pa_socket_client_unref(c->sc);
 220     c->sc = NULL;
 221
 222     if (!io) {
 223         pa_log("Connection failed: %s", pa_cstrerror(errno));
 224         return;
 225     }
 226
 227     c->fd = pa_iochannel_get_send_fd(io);
 228
 229     pa_iochannel_set_noclose(io, TRUE);
 230     pa_iochannel_free(io);
 231
 232     pa_make_tcp_socket_low_delay(c->fd);
 233
 234     pa_log_debug("Connection established");
 235     c->callback(c->fd, c->userdata);
 236 }
 237
 238 static void rtsp_cb(pa_rtsp_client *rtsp, pa_rtsp_state state, pa_headerlist* headers, void *userdata)
 239 {
 240     pa_raop_client* c = userdata;
 241     pa_assert(c);
 242     pa_assert(rtsp);
 243     pa_assert(rtsp == c->rtsp);
 244
 245     switch (state) {
 246         case STATE_CONNECT: {
 247             int i;
 248             uint8_t rsakey[512];
 249             char *key, *iv, *sac, *sdp;
 250             uint16_t rand_data;
 251             const char *ip;
 252             char *url;
 253
 254             pa_log_debug("RAOP: CONNECTED");
 255             ip = pa_rtsp_localip(c->rtsp);
 256             /* First of all set the url properly */
 257             url = pa_sprintf_malloc("rtsp://%s/%s", ip, c->sid);
 258             pa_rtsp_set_url(c->rtsp, url);
 259             pa_xfree(url);
 260
 261             /* Now encrypt our aes_public key to send to the device */
 262             i = rsa_encrypt(c->aes_key, AES_CHUNKSIZE, rsakey);
 263             pa_base64_encode(rsakey, i, &key);
 264             rtrimchar(key, '=');
 265             pa_base64_encode(c->aes_iv, AES_CHUNKSIZE, &iv);
 266             rtrimchar(iv, '=');
 267
 268             pa_random(&rand_data, sizeof(rand_data));
 269             pa_base64_encode(&rand_data, AES_CHUNKSIZE, &sac);
 270             rtrimchar(sac, '=');
 271             pa_rtsp_add_header(c->rtsp, "Apple-Challenge", sac);
 272             sdp = pa_sprintf_malloc(
 273                 "v=0\r\n"
 274                 "o=iTunes %s 0 IN IP4 %s\r\n"
 275                 "s=iTunes\r\n"
 276                 "c=IN IP4 %s\r\n"
 277                 "t=0 0\r\n"
 278                 "m=audio 0 RTP/AVP 96\r\n"
 279                 "a=rtpmap:96 AppleLossless\r\n"
 280                 "a=fmtp:96 4096 0 16 40 10 14 2 255 0 0 44100\r\n"
 281                 "a=rsaaeskey:%s\r\n"
 282                 "a=aesiv:%s\r\n",
 283                 c->sid, ip, c->host, key, iv);
 284             pa_rtsp_announce(c->rtsp, sdp);
 285             pa_xfree(key);
 286             pa_xfree(iv);
 287             pa_xfree(sac);
 288             pa_xfree(sdp);
 289             break;
 290         }
 291
 292         case STATE_ANNOUNCE:
 293             pa_log_debug("RAOP: ANNOUNCED");
 294             pa_rtsp_remove_header(c->rtsp, "Apple-Challenge");
 295             pa_rtsp_setup(c->rtsp);
 296             break;
 297
 298         case STATE_SETUP: {
 299             char *aj = pa_xstrdup(pa_headerlist_gets(headers, "Audio-Jack-Status"));
 300             pa_log_debug("RAOP: SETUP");
 301             if (aj) {
 302                 char *token, *pc;
 303                 char delimiters[] = ";";
 304                 const char* token_state = NULL;
 305                 c->jack_type = JACK_TYPE_ANALOG;
 306                 c->jack_status = JACK_STATUS_DISCONNECTED;
 307
 308                 while ((token = pa_split(aj, delimiters, &token_state))) {
 309                     if ((pc = strstr(token, "="))) {
 310                       *pc = 0;
 311                       if (!strcmp(token, "type") && !strcmp(pc+1, "digital")) {
 312                           c->jack_type = JACK_TYPE_DIGITAL;
 313                       }
 314                     } else {
 315                         if (!strcmp(token,"connected"))
 316                             c->jack_status = JACK_STATUS_CONNECTED;
 317                     }
 318                     pa_xfree(token);
 319                 }
 320                 pa_xfree(aj);
 321             } else {
 322                 pa_log_warn("Audio Jack Status missing");
 323             }
 324             pa_rtsp_record(c->rtsp);
 325             break;
 326         }
 327
 328         case STATE_RECORD: {
 329             uint32_t port = pa_rtsp_serverport(c->rtsp);
 330             pa_log_debug("RAOP: RECORDED");
 331
 332             if (!(c->sc = pa_socket_client_new_string(c->core->mainloop, c->host, port))) {
 333                 pa_log("failed to connect to server '%s:%d'", c->host, port);
 334                 return;
 335             }
 336             pa_socket_client_set_callback(c->sc, on_connection, c);
 337             break;
 338         }
 339
 340         case STATE_TEARDOWN:
 341         case STATE_SET_PARAMETER:
 342         case STATE_FLUSH:
 343             break;
 344         case STATE_DISCONNECTED:
 345             pa_assert(c->closed_callback);
 346             pa_log_debug("RTSP channel closed");
 347             if (c->fd > 0) {
 348                 pa_close(c->fd);
 349                 c->fd = -1;
 350             }
 351             if (c->sc) {
 352                 pa_socket_client_unref(c->sc);
 353                 c->sc = NULL;
 354             }
 355             c->closed_callback(c->closed_userdata);
 356             break;
 357     }
 358 }
 359
 360 pa_raop_client* pa_raop_client_new(pa_core *core, const char* host)
 361 {
 362     char *sci;
 363     struct {
 364         uint32_t a;
 365         uint32_t b;
 366         uint32_t c;
 367     } rand_data;
 368     pa_raop_client* c = pa_xnew0(pa_raop_client, 1);
 369
 370     pa_assert(core);
 371     pa_assert(host);
 372
 373     c->core = core;
 374     c->fd = -1;
 375     c->host = pa_xstrdup(host);
 376     c->rtsp = pa_rtsp_client_new("iTunes/4.6 (Macintosh; U; PPC Mac OS X 10.3)");
 377
 378     /* Initialise the AES encryption system */
 379     pa_random(c->aes_iv, sizeof(c->aes_iv));
 380     pa_random(c->aes_key, sizeof(c->aes_key));
 381     memcpy(c->aes_nv, c->aes_iv, sizeof(c->aes_nv));
 382     AES_set_encrypt_key(c->aes_key, 128, &c->aes);
 383
 384     /* Generate random instance id */
 385     pa_random(&rand_data, sizeof(rand_data));
 386     c->sid = pa_sprintf_malloc("%u", rand_data.a);
 387     sci = pa_sprintf_malloc("%08x%08x",rand_data.b, rand_data.c);
 388     pa_rtsp_add_header(c->rtsp, "Client-Instance", sci);
 389     pa_rtsp_set_callback(c->rtsp, rtsp_cb, c);
 390     if (pa_rtsp_connect(c->rtsp, c->core->mainloop, host, 5000)) {
 391         pa_rtsp_client_free(c->rtsp);
 392         pa_xfree(c->aes_iv);
 393         pa_xfree(c->aes_nv);
 394         pa_xfree(c->aes_key);
 395         return NULL;
 396     }
 397     return c;
 398 }
 399
 400
 401 void pa_raop_client_free(pa_raop_client* c)
 402 {
 403     pa_assert(c);
 404
 405     pa_xfree(c->buffer);
 406     pa_rtsp_client_free(c->rtsp);
 407     pa_xfree(c->aes_iv);
 408     pa_xfree(c->aes_nv);
 409     pa_xfree(c->aes_key);
 410     pa_xfree(c->host);
 411     pa_xfree(c);
 412 }
 413
 414
 415 static void noop(PA_GCC_UNUSED void* p) {}
 416
 417 int pa_raop_client_encode_sample(pa_raop_client* c, pa_memchunk* raw, pa_memchunk* encoded)
 418 {
 419     uint16_t len;
 420     size_t bufmax;
 421     uint8_t *bp, bpos;
 422     uint8_t *ibp, *maxibp;
 423     int size;
 424     uint8_t *b, *p;
 425     uint32_t bsize;
 426     size_t length;
 427     static uint8_t header[] = {
 428         0x24, 0x00, 0x00, 0x00,
 429         0xF0, 0xFF, 0x00, 0x00,
 430         0x00, 0x00, 0x00, 0x00,
 431         0x00, 0x00, 0x00, 0x00,
 432     };
 433     int header_size = sizeof(header);
 434
 435     pa_assert(c);
 436     pa_assert(c->fd > 0);
 437     pa_assert(raw);
 438     pa_assert(raw->memblock);
 439     pa_assert(raw->length > 0);
 440     pa_assert(encoded);
 441
 442     /* We have to send 4 byte chunks */
 443     bsize = (int)(raw->length / 4);
 444     length = bsize * 4;
 445
 446     /* Leave 16 bytes extra to allow for the ALAC header which is about 55 bits */
 447     bufmax = length + header_size + 16;
 448     if (bufmax > c->buffer_length) {
 449         if (encoded->memblock)
 450             pa_memblock_unref(encoded->memblock);
 451
 452         c->buffer = pa_xrealloc(c->buffer, bufmax);
 453         c->buffer_length = bufmax;
 454         encoded->memblock = pa_memblock_new_user(c->core->mempool, c->buffer, bufmax, noop, 0);
 455     }
 456     encoded->index = 0;
 457     encoded->length = 0;
 458     b = pa_memblock_acquire(encoded->memblock);
 459     memcpy(b, header, header_size);
 460
 461     /* Now write the actual samples */
 462     bp = b + header_size;
 463     size = bpos = 0;
 464     bit_writer(&bp,&bpos,&size,1,3); // channel=1, stereo
 465     bit_writer(&bp,&bpos,&size,0,4); // unknown
 466     bit_writer(&bp,&bpos,&size,0,8); // unknown
 467     bit_writer(&bp,&bpos,&size,0,4); // unknown
 468     bit_writer(&bp,&bpos,&size,1,1); // hassize
 469     bit_writer(&bp,&bpos,&size,0,2); // unused
 470     bit_writer(&bp,&bpos,&size,1,1); // is-not-compressed
 471
 472     /* size of data, integer, big endian */
 473     bit_writer(&bp,&bpos,&size,(bsize>>24)&0xff,8);
 474     bit_writer(&bp,&bpos,&size,(bsize>>16)&0xff,8);
 475     bit_writer(&bp,&bpos,&size,(bsize>>8)&0xff,8);
 476     bit_writer(&bp,&bpos,&size,(bsize)&0xff,8);
 477
 478     ibp = p = pa_memblock_acquire(raw->memblock);
 479     maxibp = p + raw->length - 4;
 480     while (ibp <= maxibp) {
 481         /* Byte swap stereo data */
 482         bit_writer(&bp,&bpos,&size,*(ibp+1),8);
 483         bit_writer(&bp,&bpos,&size,*(ibp+0),8);
 484         bit_writer(&bp,&bpos,&size,*(ibp+3),8);
 485         bit_writer(&bp,&bpos,&size,*(ibp+2),8);
 486         ibp += 4;
 487         raw->index += 4;
 488         raw->length -= 4;
 489     }
 490     pa_memblock_release(raw->memblock);
 491     encoded->length = header_size + size;
 492
 493     /* store the lenght (endian swapped: make this better) */
 494     len = size + header_size - 4;
 495     *(b + 2) = len >> 8;
 496     *(b + 3) = len & 0xff;
 497
 498     /* encrypt our data */
 499     aes_encrypt(c, (b + header_size), size);
 500
 501     /* We're done with the chunk */
 502     pa_memblock_release(encoded->memblock);
 503
 504     return 0;
 505 }
 506
 507
 508 void pa_raop_client_set_callback(pa_raop_client* c, pa_raop_client_cb_t callback, void *userdata)
 509 {
 510     pa_assert(c);
 511
 512     c->callback = callback;
 513     c->userdata = userdata;
 514 }
 515
 516 void pa_raop_client_set_closed_callback(pa_raop_client* c, pa_raop_client_closed_cb_t callback, void *userdata)
 517 {
 518     pa_assert(c);
 519
 520     c->closed_callback = callback;
 521     c->closed_userdata = userdata;
 522 }