| 1 | /* tclink.c - Library code for the TCLink client API. */ |
| 2 | |
| 3 | #include "tclink.h" |
| 4 | |
| 5 | #include <errno.h> |
| 6 | #include <memory.h> |
| 7 | #include <stdio.h> |
| 8 | #include <string.h> |
| 9 | |
| 10 | #ifdef WIN32 |
| 11 | #include <io.h> |
| 12 | #include <winsock2.h> |
| 13 | #else |
| 14 | #include <arpa/inet.h> |
| 15 | #include <netdb.h> |
| 16 | #include <netinet/in.h> |
| 17 | #include <stdbool.h> |
| 18 | #include <strings.h> |
| 19 | #include <sys/socket.h> |
| 20 | #include <sys/time.h> |
| 21 | #include <sys/types.h> |
| 22 | #include <unistd.h> |
| 23 | #endif |
| 24 | |
| 25 | #include <fcntl.h> |
| 26 | #include <signal.h> |
| 27 | #include <stdlib.h> |
| 28 | #include <sys/stat.h> |
| 29 | #include <sys/types.h> |
| 30 | |
| 31 | #include <openssl/crypto.h> |
| 32 | #include <openssl/err.h> |
| 33 | #include <openssl/pem.h> |
| 34 | #include <openssl/rand.h> |
| 35 | #include <openssl/ssl.h> |
| 36 | #include <openssl/x509.h> |
| 37 | |
| 38 | #ifdef WIN32 |
| 39 | #define strcasecmp(x, y) stricmp(x, y) |
| 40 | #else |
| 41 | #define closesocket(x) close(x) |
| 42 | #endif |
| 43 | |
| 44 | #define DEFAULT_HOST "pgw1.trustcommerce.com" |
| 45 | |
| 46 | /* changed from forty second to one hundred second to reflect more complicated |
| 47 | * transaction processing logic */ |
| 48 | #define TIMEOUT 100 /* seconds */ |
| 49 | #define TC_BUFF_MAX 32000 |
| 50 | #define TC_LINE_MAX ((PARAM_MAX_LEN * 2) + 2) |
| 51 | |
| 52 | char tclink_version[] = |
| 53 | TCLINK_VERSION; /* TCLINK_VERSION is defined in Makefile */ |
| 54 | char tclink_host[] = DEFAULT_HOST; |
| 55 | int tclink_port = 443; |
| 56 | |
| 57 | /*************************************************/ |
| 58 | /* Data structures used only within this module. */ |
| 59 | /*************************************************/ |
| 60 | |
| 61 | /* Variables used for transaction data. */ |
| 62 | |
| 63 | typedef struct param_data |
| 64 | { |
| 65 | char* name; |
| 66 | char* value; |
| 67 | struct param_data* next; |
| 68 | } param; |
| 69 | |
| 70 | typedef struct _TCLinkCon |
| 71 | { |
| 72 | /* Connection data */ |
| 73 | int* ip; |
| 74 | int num_ips; |
| 75 | int sd; |
| 76 | |
| 77 | /* SSL encryption */ |
| 78 | const SSL_METHOD* meth; |
| 79 | long ctx_options; |
| 80 | SSL_CTX* ctx; |
| 81 | SSL* ssl; |
| 82 | |
| 83 | /* Transaction parameters, sent and received */ |
| 84 | param *send_param_list, *send_param_tail; |
| 85 | param* recv_param_list; |
| 86 | |
| 87 | /* Connection status */ |
| 88 | int is_error; |
| 89 | int pass; |
| 90 | time_t start_time; |
| 91 | int dns; |
| 92 | |
| 93 | int (*validate_cert)(int, void*); |
| 94 | int full_ssl_close; |
| 95 | |
| 96 | } TCLinkCon; |
| 97 | |
| 98 | /************************************* |
| 99 | * Internal functions, not exported. * |
| 100 | *************************************/ |
| 101 | |
| 102 | /* Random number from min to max. */ |
| 103 | static int |
| 104 | number(int min, int max) |
| 105 | { |
| 106 | time_t t = time(0); |
| 107 | return (rand_r((unsigned int*)&t) % (max - min + 1)) + min; |
| 108 | } |
| 109 | |
| 110 | /* Check if path points to a regular file */ |
| 111 | int |
| 112 | is_regular_file(const char* path) |
| 113 | { |
| 114 | struct stat st; |
| 115 | stat(path, &st); |
| 116 | return S_ISREG(st.st_mode); |
| 117 | } |
| 118 | |
| 119 | /* Safe string copy and append functions. */ |
| 120 | #define SAFE_COPY(d, s) safe_copy((d), (s), sizeof(d)); |
| 121 | #define SAFE_APPEND(d, s) safe_append((d), (s), sizeof(d)); |
| 122 | |
| 123 | static bool |
| 124 | safe_copy(char* dst, const char* src, int size) |
| 125 | { |
| 126 | int len = (int) strlen(src); |
| 127 | if (len < size) |
| 128 | strcpy(dst, src); |
| 129 | else { |
| 130 | strncpy(dst, src, size - 1); |
| 131 | dst[size - 1] = 0; |
| 132 | } |
| 133 | return (len >= size); |
| 134 | } |
| 135 | |
| 136 | static bool |
| 137 | safe_append(char* dst, const char* src, int size) |
| 138 | { |
| 139 | int dlen = (int) strlen(dst); |
| 140 | int slen = (int) strlen(src); |
| 141 | int avail = size - dlen; |
| 142 | if (avail < 1) |
| 143 | return true; |
| 144 | |
| 145 | if (slen < avail) |
| 146 | strcpy(dst + dlen, src); |
| 147 | else { |
| 148 | strncpy(dst + dlen, src, avail - 1); |
| 149 | dst[size - 1] = 0; |
| 150 | } |
| 151 | return (slen >= avail); |
| 152 | } |
| 153 | |
| 154 | /* Add a parameter-value pair to the recieved list. */ |
| 155 | static void |
| 156 | AddRecvParam(TCLinkCon* c, const char* name, const char* value) |
| 157 | { |
| 158 | param* p; |
| 159 | |
| 160 | if (name[0] == 0 || value[0] == 0) |
| 161 | return; |
| 162 | |
| 163 | p = (param*)malloc(sizeof(param)); |
| 164 | p->name = strdup(name); |
| 165 | p->value = strdup(value); |
| 166 | p->next = c->recv_param_list; |
| 167 | c->recv_param_list = p; |
| 168 | } |
| 169 | |
| 170 | /* Add a string to the received list. */ |
| 171 | static int |
| 172 | AddRecvString(TCLinkCon* c, char* string) |
| 173 | { |
| 174 | char* ptr = strchr(string, '='); |
| 175 | if (ptr == NULL) |
| 176 | return 0; |
| 177 | |
| 178 | *ptr = 0; |
| 179 | AddRecvParam(c, string, ptr + 1); |
| 180 | |
| 181 | return 1; |
| 182 | } |
| 183 | |
| 184 | /* Deallocate the send list. */ |
| 185 | static void |
| 186 | ClearSendList(TCLinkCon* c) |
| 187 | { |
| 188 | param *p, *next; |
| 189 | for (p = c->send_param_list; p; p = next) { |
| 190 | next = p->next; |
| 191 | free(p->name); |
| 192 | free(p->value); |
| 193 | free(p); |
| 194 | } |
| 195 | |
| 196 | c->send_param_list = c->send_param_tail = NULL; |
| 197 | } |
| 198 | |
| 199 | /* Deallocate the recv list. */ |
| 200 | static void |
| 201 | ClearRecvList(TCLinkCon* c) |
| 202 | { |
| 203 | param *p, *next; |
| 204 | for (p = c->recv_param_list; p; p = next) { |
| 205 | next = p->next; |
| 206 | free(p->name); |
| 207 | free(p->value); |
| 208 | free(p); |
| 209 | } |
| 210 | |
| 211 | c->recv_param_list = NULL; |
| 212 | } |
| 213 | |
| 214 | void |
| 215 | do_SSL_randomize(void) |
| 216 | { |
| 217 | enum |
| 218 | { |
| 219 | RAND_VALS = 32 |
| 220 | }; |
| 221 | int randbuf[RAND_VALS]; |
| 222 | char fname[512]; |
| 223 | int use_rand_file; |
| 224 | time_t t; |
| 225 | int i, c; |
| 226 | |
| 227 | /* if they have a /dev/urandom we can skip this function */ |
| 228 | if (RAND_status() != 0) |
| 229 | return; |
| 230 | |
| 231 | t = time(0); |
| 232 | RAND_seed((char*)&t, sizeof(time_t)); |
| 233 | |
| 234 | /* have they specified a random file with RANDFILE environment variable? */ |
| 235 | use_rand_file = RAND_file_name(fname, sizeof(fname)) ? 1 : 0; |
| 236 | if (use_rand_file) |
| 237 | RAND_load_file(fname, 4096); |
| 238 | |
| 239 | /* stuff it with packets of random numbers until it is satisfied */ |
| 240 | for (i = 0; i < 256 && RAND_status() == 0; i++) { |
| 241 | for (c = 0; c < RAND_VALS; c++) |
| 242 | randbuf[c] = rand_r((unsigned int*)&t); |
| 243 | RAND_seed((char*)randbuf, sizeof(int) * RAND_VALS); |
| 244 | } |
| 245 | } |
| 246 | |
| 247 | /* Make sure all of the ssl objects are properly initialized. |
| 248 | */ |
| 249 | static int |
| 250 | init_ssl(TCLinkCon* c) |
| 251 | { |
| 252 | int ret = 1; |
| 253 | |
| 254 | /* Sanity Check */ |
| 255 | if (c == NULL) |
| 256 | return 0; |
| 257 | |
| 258 | /* do some SSL setup */ |
| 259 | if (!c->meth) { |
| 260 | do_SSL_randomize(); /* handle systems without /dev/urandom */ |
| 261 | #if OPENSSL_VERSION_NUMBER < 0x10100000L |
| 262 | c->meth = SSLv23_client_method(); |
| 263 | c->ctx_options = SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3 | SSL_OP_NO_TLSv1; |
| 264 | #else |
| 265 | c->meth = TLS_client_method(); |
| 266 | c->ctx_options = SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3 | SSL_OP_NO_TLSv1 | |
| 267 | SSL_OP_NO_TLSv1_1 | SSL_OP_NO_TICKET; |
| 268 | #endif |
| 269 | } |
| 270 | |
| 271 | if (!c->ctx) { |
| 272 | int val; |
| 273 | int is_file; |
| 274 | |
| 275 | c->ctx = SSL_CTX_new(c->meth); |
| 276 | if (!c->ctx) |
| 277 | return 0; |
| 278 | /* set options */ |
| 279 | if (c->ctx_options) |
| 280 | SSL_CTX_set_options(c->ctx, c->ctx_options); |
| 281 | #if OPENSSL_VERSION_NUMBER >= 0x10100000L |
| 282 | SSL_CTX_set_min_proto_version(c->ctx, TLS1_2_VERSION); |
| 283 | #endif |
| 284 | |
| 285 | is_file = is_regular_file(TCLINK_CA_PATH); |
| 286 | val = SSL_CTX_load_verify_locations( |
| 287 | c->ctx, is_file ? TCLINK_CA_PATH : NULL, is_file ? NULL : TCLINK_CA_PATH); |
| 288 | |
| 289 | if (!val) |
| 290 | return 0; // failed to populate cert store |
| 291 | |
| 292 | /* turn on certificate chain validation */ |
| 293 | SSL_CTX_set_verify(c->ctx, SSL_VERIFY_PEER, NULL); |
| 294 | } |
| 295 | |
| 296 | if (!c->ssl) { |
| 297 | c->ssl = SSL_new(c->ctx); |
| 298 | if (!c->ssl) { |
| 299 | SSL_CTX_free(c->ctx); |
| 300 | c->ctx = NULL; |
| 301 | return 0; |
| 302 | } |
| 303 | } |
| 304 | |
| 305 | return ret; |
| 306 | } |
| 307 | |
| 308 | /* Open a socket to the host_ip specified. Returns the socket's file |
| 309 | * descriptor on success (the open attempt is underway) or -1 for failure |
| 310 | * (should never happen in practice). Note that this function DOES NOT block |
| 311 | * and wait for the connection; you'll need to select() on the socket later to |
| 312 | * see if it opened successfully. |
| 313 | */ |
| 314 | static int |
| 315 | BeginConnection(TCLinkCon* c, int host_ip) |
| 316 | { |
| 317 | struct sockaddr_in sa; |
| 318 | int sd; |
| 319 | |
| 320 | sd = socket(AF_INET, SOCK_STREAM, 0); |
| 321 | if (sd < 0) |
| 322 | return -1; |
| 323 | |
| 324 | #ifdef WIN32 |
| 325 | u_long param = 1; |
| 326 | ioctlsocket(sd, FIONBIO, ¶m); |
| 327 | #else |
| 328 | fcntl(sd, F_SETFL, O_NONBLOCK); |
| 329 | #endif |
| 330 | |
| 331 | memset(&sa, 0, sizeof(sa)); |
| 332 | sa.sin_family = AF_INET; |
| 333 | sa.sin_addr.s_addr = host_ip; |
| 334 | sa.sin_port = htons(tclink_port); |
| 335 | |
| 336 | connect(sd, (struct sockaddr*)&sa, sizeof(sa)); |
| 337 | |
| 338 | return sd; |
| 339 | } |
| 340 | |
| 341 | /* This function is called on a socket file descriptor once the connection has |
| 342 | * been established and we're ready to negotiate SSL. If the SSL handshake |
| 343 | * fails for some reason (such as the host on the other end not using SSL), it |
| 344 | * will return 0 for failure. Success returns 1. |
| 345 | */ |
| 346 | static int |
| 347 | FinishConnection(TCLinkCon* c, int sd) |
| 348 | { |
| 349 | int ssl_connected, is_error, errcode, res; |
| 350 | X509* server_cert; |
| 351 | time_t start, remaining; |
| 352 | fd_set in, out, err; |
| 353 | struct timeval tv; |
| 354 | |
| 355 | /* check if socket has connected successfully */ |
| 356 | int val; |
| 357 | socklen_t size = 4; |
| 358 | getsockopt(sd, SOL_SOCKET, SO_ERROR, (char*)&val, &size); |
| 359 | if (val != 0) |
| 360 | return 0; |
| 361 | |
| 362 | if (c->ssl) |
| 363 | SSL_clear(c->ssl); |
| 364 | |
| 365 | ERR_clear_error(); |
| 366 | |
| 367 | // Call init_ssl to make sure everything is setup properly. |
| 368 | if (!init_ssl(c)) |
| 369 | return 0; |
| 370 | |
| 371 | SSL_set_fd(c->ssl, sd); |
| 372 | |
| 373 | ssl_connected = 0; |
| 374 | is_error = 0; |
| 375 | start = time(0); |
| 376 | |
| 377 | while (!ssl_connected && !is_error) { |
| 378 | |
| 379 | remaining = 5 - (time(0) - start); |
| 380 | if (remaining <= 0) { |
| 381 | is_error = 1; |
| 382 | break; |
| 383 | } |
| 384 | |
| 385 | res = SSL_connect(c->ssl); |
| 386 | |
| 387 | ssl_connected = ((res == 1) && SSL_is_init_finished(c->ssl)); |
| 388 | |
| 389 | if (!ssl_connected) { |
| 390 | FD_ZERO(&in); |
| 391 | FD_SET((unsigned)sd, &in); |
| 392 | FD_ZERO(&out); |
| 393 | FD_SET((unsigned)sd, &out); |
| 394 | FD_ZERO(&err); |
| 395 | FD_SET((unsigned)sd, &err); |
| 396 | /* the documentation does not suggest that both error types occur at the |
| 397 | * same time so the retry logic will consume all the outstanding events we |
| 398 | * do not actually use oob data, but if it is sent, it is treated as an |
| 399 | * error all the same |
| 400 | */ |
| 401 | errcode = SSL_get_error(c->ssl, res); |
| 402 | switch (errcode) { |
| 403 | case SSL_ERROR_NONE: |
| 404 | /* no error, we should have a connection, check again */ |
| 405 | break; |
| 406 | |
| 407 | case SSL_ERROR_WANT_READ: |
| 408 | /* no error, just wait for more data */ |
| 409 | tv.tv_sec = remaining; |
| 410 | tv.tv_usec = 0; |
| 411 | /* posix-2001 says the function will modify the appropriate |
| 412 | * descriptors */ |
| 413 | if (select(sd + 1, &in, NULL, &err, &tv) < 0 || |
| 414 | FD_ISSET((unsigned)sd, &err)) |
| 415 | is_error = 1; |
| 416 | break; |
| 417 | case SSL_ERROR_WANT_WRITE: |
| 418 | /* no error, just wait for more data */ |
| 419 | tv.tv_sec = remaining; |
| 420 | tv.tv_usec = 0; |
| 421 | if (select(sd + 1, NULL, &out, &err, &tv) < 0 || |
| 422 | FD_ISSET((unsigned)sd, &err)) |
| 423 | is_error = 1; |
| 424 | break; |
| 425 | case SSL_ERROR_ZERO_RETURN: /* peer closed the connection */ |
| 426 | case SSL_ERROR_SSL: /* error in SSL handshake */ |
| 427 | default: |
| 428 | is_error = 1; |
| 429 | } |
| 430 | } |
| 431 | } |
| 432 | |
| 433 | if (is_error) { |
| 434 | return 0; |
| 435 | } |
| 436 | |
| 437 | #ifdef WIN32 |
| 438 | u_long param = 0; |
| 439 | ioctlsocket(sd, FIONBIO, ¶m); // make the socket blocking again |
| 440 | #else |
| 441 | fcntl(sd, F_SETFL, 0); /* make the socket blocking again */ |
| 442 | #endif |
| 443 | |
| 444 | /* verify that server certificate is authentic */ |
| 445 | server_cert = SSL_get_peer_certificate(c->ssl); |
| 446 | if (!server_cert) { |
| 447 | return 0; |
| 448 | } |
| 449 | if (c->validate_cert && c->validate_cert(0, server_cert) != 0) { |
| 450 | X509_free(server_cert); |
| 451 | return 0; |
| 452 | } |
| 453 | X509_free(server_cert); |
| 454 | |
| 455 | return 1; |
| 456 | } |
| 457 | |
| 458 | /* This function should be called on list of socket file descriptors (sd) to |
| 459 | * determine if any have opened successfully. If so, it will return which one |
| 460 | * (index into the array). Otherwise it returns -1 if none have successfully |
| 461 | * opened. This function will block for a maximum of 3 seconds. As this function |
| 462 | * calls FinishConnection(), you shouldn't need to do anything special after it |
| 463 | * returns success - the socket is set up and ready for use. |
| 464 | */ |
| 465 | static int |
| 466 | CheckConnection(TCLinkCon* c, int* sd, int num_sd) |
| 467 | { |
| 468 | fd_set wr_set, err_set; |
| 469 | struct timeval tv; |
| 470 | int max_sd = -1, i; |
| 471 | |
| 472 | tv.tv_sec = 3; /* wait 3 seconds for soc->mething to happen */ |
| 473 | tv.tv_usec = 0; |
| 474 | |
| 475 | /* build the fd_sets used for select() */ |
| 476 | FD_ZERO(&wr_set); |
| 477 | FD_ZERO(&err_set); |
| 478 | for (i = 0; i < num_sd; i++) { |
| 479 | if (sd[i] < 0) |
| 480 | continue; |
| 481 | FD_SET(sd[i], &wr_set); |
| 482 | FD_SET(sd[i], &err_set); |
| 483 | if (sd[i] > max_sd) |
| 484 | max_sd = sd[i]; |
| 485 | } |
| 486 | |
| 487 | /* run the select and see what we have waiting for us */ |
| 488 | if (select(max_sd + 1, NULL, &wr_set, &err_set, &tv) < 1) |
| 489 | return -1; /* I hope this never happens */ |
| 490 | |
| 491 | for (i = 0; i < num_sd; i++) |
| 492 | if (sd[i] >= 0) { |
| 493 | if (FD_ISSET(sd[i], &err_set)) { |
| 494 | /* error - close the socket and mark it defunct */ |
| 495 | close(sd[i]); |
| 496 | sd[i] = -1; |
| 497 | } else if (FD_ISSET(sd[i], &wr_set)) { |
| 498 | /* socket has opened! try to negotiate SSL */ |
| 499 | if (FinishConnection(c, sd[i])) { |
| 500 | /* socket is ready to go, so return success */ |
| 501 | c->sd = sd[i]; |
| 502 | return i; |
| 503 | } else { |
| 504 | /* SSL handshake had errors, close the socket and mark it defunct */ |
| 505 | close(sd[i]); |
| 506 | sd[i] = -1; |
| 507 | // Clear the ssl environment too. |
| 508 | if (c->ssl) { |
| 509 | SSL_free(c->ssl); |
| 510 | c->ssl = NULL; |
| 511 | } |
| 512 | } |
| 513 | } |
| 514 | } |
| 515 | |
| 516 | /* if we get here, nothing much interesting happened during those 3 seconds */ |
| 517 | return -1; |
| 518 | } |
| 519 | |
| 520 | /* Open a connection to one of the TrustCommerce gateway servers. */ |
| 521 | static int |
| 522 | Connect(TCLinkCon* c, int host_hash) |
| 523 | { |
| 524 | struct hostent default_he; |
| 525 | char* addr_list[3]; |
| 526 | int addr[2]; |
| 527 | unsigned int** gw = NULL; |
| 528 | |
| 529 | enum |
| 530 | { |
| 531 | MAX_HOSTS = 32 |
| 532 | }; |
| 533 | time_t last_connect[MAX_HOSTS]; |
| 534 | int sd[MAX_HOSTS]; |
| 535 | int num_sd = 0; |
| 536 | int host; |
| 537 | |
| 538 | int i, j, sort, sort_val; |
| 539 | |
| 540 | for (i = 0; i < MAX_HOSTS; i++) |
| 541 | sd[i] = -1; |
| 542 | |
| 543 | c->sd = -1; |
| 544 | c->is_error = 0; |
| 545 | |
| 546 | srand((unsigned) time(0)); |
| 547 | |
| 548 | /* These are used as BACKUP ONLY if the DNS if offline. */ |
| 549 | addr[0] = inet_addr("206.82.213.130"); |
| 550 | addr[1] = inet_addr("208.72.241.130"); |
| 551 | addr_list[0] = (char*)&addr[0]; |
| 552 | addr_list[1] = (char*)&addr[1]; |
| 553 | addr_list[2] = 0; |
| 554 | default_he.h_addr_list = addr_list; |
| 555 | |
| 556 | /* determine IP addresses of gateway */ |
| 557 | if (!c->ip) { |
| 558 | #ifndef __APPLE__ |
| 559 | int herr = 0; |
| 560 | char tmpbuf[4096]; |
| 561 | struct hostent tmpres; |
| 562 | #endif |
| 563 | struct hostent * he = NULL; |
| 564 | int ret = -1; |
| 565 | |
| 566 | #ifdef __APPLE__ |
| 567 | he = gethostbyname(tclink_host); |
| 568 | if (he) |
| 569 | ret = 0; |
| 570 | #else |
| 571 | ret = |
| 572 | gethostbyname_r(tclink_host, &tmpres, tmpbuf, sizeof(tmpbuf), &he, &herr); |
| 573 | if (ret) |
| 574 | he = NULL; |
| 575 | |
| 576 | #endif |
| 577 | if (ret == 0 && he != NULL) { |
| 578 | c->dns = 1; |
| 579 | } else { |
| 580 | /* fall back to hardcoded IPs in an emergency */ |
| 581 | c->dns = 0; |
| 582 | he = &default_he; |
| 583 | } |
| 584 | |
| 585 | for (c->num_ips = 0; he->h_addr_list[c->num_ips]; c->num_ips++) |
| 586 | ; |
| 587 | |
| 588 | c->ip = (int*)malloc(c->num_ips * sizeof(int)); |
| 589 | gw = (int unsigned**)he->h_addr_list; |
| 590 | |
| 591 | /* sort the IP address list before storing it */ |
| 592 | for (i = 0; i < c->num_ips; i++) { |
| 593 | sort = 0; |
| 594 | sort_val = *gw[0]; |
| 595 | for (j = 1; j < c->num_ips; j++) |
| 596 | if (*gw[j] > (unsigned int)sort_val) { |
| 597 | sort = j; |
| 598 | sort_val = *gw[j]; |
| 599 | } |
| 600 | |
| 601 | c->ip[i] = sort_val; |
| 602 | *gw[sort] = 0; |
| 603 | } |
| 604 | } |
| 605 | |
| 606 | if (!init_ssl(c)) |
| 607 | return 0; |
| 608 | |
| 609 | /* This loop works as follows: |
| 610 | * Grab the first host. Try to open a connection to it. If there was an |
| 611 | * error (host down or unreachable) go to the next one. If nothing has |
| 612 | * happened after 3 seconds, open a second socket (the first one is still |
| 613 | * open!) and try with the next fail-over host. Continue to do this for a |
| 614 | * maximum of MAX_HOSTS sockets, or until our TIMEOUT value runs out. We also |
| 615 | * keep track of how recently we tried to connect to a given host, so that we |
| 616 | * avoid saturating the machines in a heavy-load situation (which could be |
| 617 | * caused by anything from heavy internet lag between the local host and the |
| 618 | * TrustCommerce servers, to heavy load on the servers themselves due to half |
| 619 | * a million people trying to run credit card transactions in the same half |
| 620 | * second - unlikely, but certainly possible.) |
| 621 | */ |
| 622 | c->start_time = time(0); |
| 623 | c->pass = 1; |
| 624 | memset(last_connect, 0, MAX_HOSTS * sizeof(time_t)); |
| 625 | |
| 626 | host = host_hash % c->num_ips; |
| 627 | |
| 628 | for (; time(0) < (c->start_time + TIMEOUT); c->pass++) { |
| 629 | /* retry the first host at least once */ |
| 630 | if (c->pass > 2) |
| 631 | host += 1; |
| 632 | if (host >= c->num_ips) |
| 633 | host = 0; |
| 634 | |
| 635 | /* only connect if we haven't tried this host before, or it's been a little |
| 636 | * while (note random modifier to help stagger network traffic) */ |
| 637 | if (last_connect[host] == 0 || |
| 638 | (time(0) - last_connect[host]) >= number(TIMEOUT / 4, TIMEOUT)) { |
| 639 | if (num_sd < MAX_HOSTS) { |
| 640 | /* fire up a new connection to this host */ |
| 641 | if (c->pass != 1) |
| 642 | last_connect[host] = time(0); |
| 643 | |
| 644 | sd[num_sd] = BeginConnection(c, c->ip[host]); |
| 645 | if (sd[num_sd] >= 0) |
| 646 | num_sd++; |
| 647 | } |
| 648 | } |
| 649 | |
| 650 | /* scan all current sockets and see if we've made a successful connection |
| 651 | * somewhere. note that this also includes SSL and all that sort of fun, |
| 652 | * so once it returns success, we're all done. */ |
| 653 | if (num_sd > 0) { |
| 654 | if (CheckConnection(c, sd, num_sd) >= 0) { |
| 655 | /* Success: close all other file handles and return */ |
| 656 | for (i = 0; i < num_sd; i++) |
| 657 | if (sd[i] >= 0 && sd[i] != c->sd) |
| 658 | close(sd[i]); |
| 659 | |
| 660 | return 1; |
| 661 | } |
| 662 | } |
| 663 | |
| 664 | usleep(1000); // sleep for 1 millisecond |
| 665 | } |
| 666 | |
| 667 | // We couldn't connect successfully to any endpoint/s. |
| 668 | // Close any open sockets to avoid leaks. |
| 669 | for (i = 0; i < num_sd; i++) { |
| 670 | if (sd[i] >= 0) { |
| 671 | close(sd[i]); |
| 672 | sd[i] = -1; |
| 673 | } |
| 674 | } |
| 675 | |
| 676 | return 0; |
| 677 | } |
| 678 | |
| 679 | /* Send a chunk of data through a connection previously opened with Connect(). |
| 680 | */ |
| 681 | static int |
| 682 | Send(TCLinkCon* c, const char* string) |
| 683 | { |
| 684 | if (SSL_write(c->ssl, string, (unsigned) strlen(string)) < 0) |
| 685 | return 0; |
| 686 | |
| 687 | return 1; |
| 688 | } |
| 689 | |
| 690 | /* Peel a line off the current input. Note that this DOESN'T necessarily wait |
| 691 | * for all input to come in, only up to a "\n". -1 is returned for a network |
| 692 | * error, otherwise it returns the length of the line read. If there is not a |
| 693 | * complete line pending for read this will block until there is, or an error |
| 694 | * occurs. |
| 695 | */ |
| 696 | static int |
| 697 | ReadLine(TCLinkCon* c, char* buffer, char* destbuf) |
| 698 | { |
| 699 | struct timeval tv; |
| 700 | fd_set read; |
| 701 | fd_set error; |
| 702 | int sel; |
| 703 | |
| 704 | while (1) /* we wait for a line to come in or an error to occur */ |
| 705 | { |
| 706 | char* eol = strchr(buffer, '\n'); |
| 707 | if (eol != NULL) { |
| 708 | /* peel off the line and return it */ |
| 709 | *eol++ = 0; |
| 710 | safe_copy(destbuf, buffer, TC_LINE_MAX); |
| 711 | memmove(buffer, eol, strlen(eol) + 1); |
| 712 | return (int) strlen(destbuf); |
| 713 | } else { |
| 714 | if (c->is_error == 1) |
| 715 | return -1; |
| 716 | |
| 717 | /* do socket work to grab the most recent chunk of incoming data */ |
| 718 | FD_ZERO(&read); |
| 719 | FD_SET(c->sd, &read); |
| 720 | FD_ZERO(&error); |
| 721 | FD_SET(c->sd, &error); |
| 722 | tv.tv_sec = TIMEOUT; |
| 723 | tv.tv_usec = 0; |
| 724 | |
| 725 | sel = select(c->sd + 1, &read, NULL, &error, &tv); |
| 726 | if (sel < 1) |
| 727 | c->is_error = 1; |
| 728 | else if (FD_ISSET(c->sd, &error)) |
| 729 | c->is_error = 1; |
| 730 | else if (FD_ISSET(c->sd, &read)) { |
| 731 | int buffer_end = (int) strlen(buffer); |
| 732 | int size = |
| 733 | SSL_read(c->ssl, buffer + buffer_end, TC_BUFF_MAX - 1 - buffer_end); |
| 734 | if (size == 0) { |
| 735 | int error_type = SSL_get_error(c->ssl, size); |
| 736 | switch (error_type) { |
| 737 | /* this would never happen in practice */ |
| 738 | case SSL_ERROR_NONE: |
| 739 | /* this wouldn't happen either because the ssl transport is blocking |
| 740 | */ |
| 741 | case SSL_ERROR_WANT_READ: |
| 742 | case SSL_ERROR_WANT_WRITE: |
| 743 | buffer[buffer_end] = 0; |
| 744 | break; |
| 745 | |
| 746 | /* these others should not really happen but if they do, we bail */ |
| 747 | /* we would never get any more data and it looks like the callee is |
| 748 | * expecting something */ |
| 749 | case SSL_ERROR_ZERO_RETURN: |
| 750 | case SSL_ERROR_WANT_CONNECT: |
| 751 | case SSL_ERROR_WANT_ACCEPT: |
| 752 | case SSL_ERROR_SYSCALL: |
| 753 | case SSL_ERROR_WANT_X509_LOOKUP: |
| 754 | case SSL_ERROR_SSL: |
| 755 | default: |
| 756 | c->is_error = 1; |
| 757 | break; |
| 758 | } |
| 759 | } else if (size < 0) |
| 760 | c->is_error = 1; |
| 761 | else |
| 762 | buffer[buffer_end + size] = 0; |
| 763 | } |
| 764 | } |
| 765 | } |
| 766 | } |
| 767 | |
| 768 | /* Closes a connection opened with Connect() and frees memory associated with |
| 769 | * it. You ONLY need to Close() connections which opened successfully; those |
| 770 | * that don't clean up after themselves before Connect() returns. |
| 771 | */ |
| 772 | static int |
| 773 | Close(TCLinkCon* c) |
| 774 | { |
| 775 | if (c->ssl) { |
| 776 | /* The full shutdown presented here is more for completeness than necessity; |
| 777 | * at this point in the application, we have already received the end |
| 778 | * trailer (or bust) which is generally accompanied by a close notify |
| 779 | * message. If the software chooses to respond to the close notify (per TLS |
| 780 | * specification) this would result in at least reading the incoming close |
| 781 | * notify and issuing our own. Because this entails an additional round |
| 782 | * trip that is not needed (the transaction is done after the accompanying |
| 783 | * END), there does not appear to be a benefit to it at all. By default |
| 784 | * though, this configuration is enabled and can be disabled by the |
| 785 | * integrator for performance reasons. |
| 786 | */ |
| 787 | if (c->full_ssl_close) { |
| 788 | int status = SSL_shutdown(c->ssl); |
| 789 | if (status == 0) |
| 790 | status = SSL_shutdown(c->ssl); |
| 791 | } else |
| 792 | SSL_set_shutdown(c->ssl, SSL_SENT_SHUTDOWN | SSL_RECEIVED_SHUTDOWN); |
| 793 | } |
| 794 | |
| 795 | if (c->sd >= 0) { |
| 796 | close(c->sd); |
| 797 | c->sd = -1; |
| 798 | } |
| 799 | |
| 800 | return 1; |
| 801 | } |
| 802 | |
| 803 | static void |
| 804 | stuff_string(char* buf, int* len, int size, const char* add) |
| 805 | { |
| 806 | int newlen = (int) strlen(add); |
| 807 | if ((*len + newlen) >= size) |
| 808 | newlen = size - *len - 1; |
| 809 | if (newlen < 1) |
| 810 | return; |
| 811 | strncpy(buf + *len, add, newlen); |
| 812 | *len += newlen; |
| 813 | buf[*len] = 0; |
| 814 | } |
| 815 | |
| 816 | /********************************************** |
| 817 | * API functions exported to the user client. * |
| 818 | **********************************************/ |
| 819 | |
| 820 | TCLinkHandle |
| 821 | TCLinkCreate() |
| 822 | { |
| 823 | extern int TCLinkDefaultValidate(int, void*); |
| 824 | |
| 825 | TCLinkCon* c = (TCLinkCon*)malloc(sizeof(TCLinkCon)); |
| 826 | |
| 827 | c->ip = NULL; |
| 828 | c->num_ips = 0; |
| 829 | c->sd = -1; |
| 830 | |
| 831 | c->meth = NULL; |
| 832 | c->ctx_options = 0; |
| 833 | c->ctx = NULL; |
| 834 | c->ssl = NULL; |
| 835 | |
| 836 | c->send_param_list = NULL; |
| 837 | c->send_param_tail = NULL; |
| 838 | c->recv_param_list = NULL; |
| 839 | |
| 840 | c->is_error = 0; |
| 841 | c->pass = 0; |
| 842 | c->start_time = 0; |
| 843 | c->dns = -1; |
| 844 | |
| 845 | c->validate_cert = TCLinkDefaultValidate; |
| 846 | c->full_ssl_close = 1; |
| 847 | |
| 848 | return (TCLinkHandle)c; |
| 849 | } |
| 850 | |
| 851 | int |
| 852 | TCLinkSetFullClose(TCLinkHandle handle, int full_ssl_close) |
| 853 | { |
| 854 | TCLinkCon* c = (TCLinkCon*)handle; |
| 855 | int swap = c->full_ssl_close; |
| 856 | c->full_ssl_close = full_ssl_close ? 1 : 0; |
| 857 | return swap; |
| 858 | } |
| 859 | |
| 860 | void |
| 861 | TCLinkSetValidateCallback(TCLinkHandle handle, int (*validate_cert)(int, void*)) |
| 862 | { |
| 863 | TCLinkCon* c = (TCLinkCon*)handle; |
| 864 | if (validate_cert == NULL) { |
| 865 | extern int TCLinkDefaultValidate(int, void*); |
| 866 | c->validate_cert = TCLinkDefaultValidate; |
| 867 | } else |
| 868 | c->validate_cert = validate_cert; |
| 869 | } |
| 870 | |
| 871 | void |
| 872 | TCLinkPushParam(TCLinkHandle handle, const char* name, const char* value) |
| 873 | { |
| 874 | param* p; |
| 875 | char* ch; |
| 876 | |
| 877 | TCLinkCon* c = (TCLinkCon*)handle; |
| 878 | |
| 879 | if (name && value) { |
| 880 | p = (param*)malloc(sizeof(param)); |
| 881 | p->name = strdup(name); |
| 882 | p->value = strdup(value); |
| 883 | p->next = NULL; |
| 884 | if (c->send_param_tail) |
| 885 | c->send_param_tail->next = p; |
| 886 | else |
| 887 | c->send_param_list = p; |
| 888 | c->send_param_tail = p; |
| 889 | |
| 890 | /* remove newlines and equals signs from the parameter name */ |
| 891 | for (ch = p->name; *ch; ch++) |
| 892 | if (*ch == '=' || *ch == '\n') |
| 893 | *ch = ' '; |
| 894 | |
| 895 | /* remove newlines from the value */ |
| 896 | for (ch = p->value; *ch; ch++) |
| 897 | if (*ch == '\n') |
| 898 | *ch = ' '; |
| 899 | } |
| 900 | } |
| 901 | |
| 902 | void |
| 903 | TCLinkSend(TCLinkHandle handle) |
| 904 | { |
| 905 | param *p, *next; |
| 906 | char buf[TC_BUFF_MAX], destbuf[TC_LINE_MAX]; |
| 907 | const int BUF2_LEN = 2048; |
| 908 | char buf2[BUF2_LEN]; |
| 909 | int host_hash = 1; |
| 910 | int retval = 0; |
| 911 | bool full = false; |
| 912 | |
| 913 | TCLinkCon* c = (TCLinkCon*)handle; |
| 914 | |
| 915 | ClearRecvList(c); |
| 916 | |
| 917 | /* build most of the string we will send to the processor */ |
| 918 | sprintf(buf, "BEGIN\nversion=%s\n", tclink_version); |
| 919 | |
| 920 | for (p = c->send_param_list; p; p = next) { |
| 921 | next = p->next; |
| 922 | full = full || SAFE_COPY(buf2, p->name); |
| 923 | full = full || SAFE_APPEND(buf2, "="); |
| 924 | full = full || SAFE_APPEND(buf2, p->value); |
| 925 | full = full || SAFE_APPEND(buf2, "\n"); |
| 926 | full = full || SAFE_APPEND(buf, buf2); |
| 927 | if (!full && !strcasecmp(p->name, "custid")) { |
| 928 | |
| 929 | host_hash = atoi(p->value); |
| 930 | host_hash = (host_hash / 100) + (host_hash % 100); |
| 931 | } |
| 932 | |
| 933 | free(p->name); |
| 934 | free(p->value); |
| 935 | free(p); |
| 936 | } |
| 937 | |
| 938 | c->send_param_list = c->send_param_tail = NULL; |
| 939 | |
| 940 | /* try to make the connection */ |
| 941 | if (!full && !Connect(c, host_hash)) { |
| 942 | Close(c); /* clean up any memory Connect() may have left lying around */ |
| 943 | AddRecvParam(c, "status", "error"); |
| 944 | AddRecvParam(c, "errortype", "cantconnect"); |
| 945 | return; |
| 946 | } |
| 947 | |
| 948 | if (!full) { |
| 949 | /* append some data about the connection */ |
| 950 | snprintf( |
| 951 | buf2, BUF2_LEN, "pass=%d\ntime=%ld\n", c->pass, time(0) - c->start_time); |
| 952 | full = full || SAFE_APPEND(buf, buf2); |
| 953 | if (c->dns != 1) |
| 954 | SAFE_APPEND(buf, "dns=n\n"); |
| 955 | full = full || SAFE_APPEND(buf, "END\n"); |
| 956 | } |
| 957 | |
| 958 | if (full) { |
| 959 | Close(c); |
| 960 | AddRecvParam(c, "status", "baddata"); |
| 961 | AddRecvParam(c, "error", "badlength"); |
| 962 | AddRecvParam(c, "offenders", "request"); |
| 963 | return; |
| 964 | } |
| 965 | |
| 966 | /* send the data */ |
| 967 | if (Send(c, buf)) { |
| 968 | int state = 0; |
| 969 | buf[0] = destbuf[0] = 0; /* recycle buf */ |
| 970 | c->is_error = 0; |
| 971 | while (1) { |
| 972 | int len = ReadLine(c, buf, destbuf); |
| 973 | if (len == 0) |
| 974 | continue; |
| 975 | if (len < 0) |
| 976 | break; |
| 977 | if (strcasecmp(destbuf, "BEGIN") == 0) { |
| 978 | if (state != 0) { |
| 979 | state = -1; |
| 980 | break; |
| 981 | } |
| 982 | state = 1; |
| 983 | } else if (strcasecmp(destbuf, "END") == 0) { |
| 984 | state = (state != 1) ? -1 : 2; |
| 985 | break; |
| 986 | } else { |
| 987 | if (state != 1 || !AddRecvString(c, destbuf)) { |
| 988 | state = -1; |
| 989 | break; |
| 990 | } |
| 991 | } |
| 992 | } |
| 993 | if (state == 2) |
| 994 | retval = 1; |
| 995 | } |
| 996 | |
| 997 | Close(c); |
| 998 | |
| 999 | if (!retval) { |
| 1000 | ClearRecvList(c); |
| 1001 | AddRecvParam(c, "status", "error"); |
| 1002 | AddRecvParam(c, "errortype", "linkfailure"); |
| 1003 | } |
| 1004 | } |
| 1005 | |
| 1006 | char* |
| 1007 | TCLinkGetResponse(TCLinkHandle handle, const char* name, char* value) |
| 1008 | { |
| 1009 | param* p; |
| 1010 | TCLinkCon* c = (TCLinkCon*)handle; |
| 1011 | |
| 1012 | for (p = c->recv_param_list; p; p = p->next) |
| 1013 | if (strcasecmp(name, p->name) == 0) { |
| 1014 | safe_copy(value, p->value, PARAM_MAX_LEN); |
| 1015 | return value; |
| 1016 | } |
| 1017 | |
| 1018 | return NULL; |
| 1019 | } |
| 1020 | |
| 1021 | char* |
| 1022 | TCLinkGetEntireResponse(TCLinkHandle handle, char* buf, int size) |
| 1023 | { |
| 1024 | param* p; |
| 1025 | int len = 0; |
| 1026 | TCLinkCon* c = (TCLinkCon*)handle; |
| 1027 | |
| 1028 | for (p = c->recv_param_list; p; p = p->next) { |
| 1029 | stuff_string(buf, &len, size, p->name); |
| 1030 | stuff_string(buf, &len, size, "="); |
| 1031 | stuff_string(buf, &len, size, p->value); |
| 1032 | stuff_string(buf, &len, size, "\n"); |
| 1033 | } |
| 1034 | |
| 1035 | return buf; |
| 1036 | } |
| 1037 | |
| 1038 | void |
| 1039 | TCLinkDestroy(TCLinkHandle handle) |
| 1040 | { |
| 1041 | TCLinkCon* c = (TCLinkCon*)handle; |
| 1042 | if (!c) |
| 1043 | return; |
| 1044 | |
| 1045 | ClearSendList(c); |
| 1046 | ClearRecvList(c); |
| 1047 | Close(c); |
| 1048 | |
| 1049 | if (c->ip) |
| 1050 | free(c->ip); |
| 1051 | |
| 1052 | if (c->ssl) { |
| 1053 | SSL_free(c->ssl); |
| 1054 | c->ssl = NULL; |
| 1055 | } |
| 1056 | |
| 1057 | if (c->ctx) { |
| 1058 | SSL_CTX_free(c->ctx); |
| 1059 | c->ctx = NULL; |
| 1060 | } |
| 1061 | |
| 1062 | free(c); |
| 1063 | } |
| 1064 | |
| 1065 | char* |
| 1066 | TCLinkGetVersion(char* buf) |
| 1067 | { |
| 1068 | strcpy(buf, tclink_version); |
| 1069 | return buf; |
| 1070 | } |