Annotation of embedaddon/curl/lib/security.c, revision 1.1
1.1 ! misho 1: /* This source code was modified by Martin Hedenfalk <mhe@stacken.kth.se> for
! 2: * use in Curl. His latest changes were done 2000-09-18.
! 3: *
! 4: * It has since been patched and modified a lot by Daniel Stenberg
! 5: * <daniel@haxx.se> to make it better applied to curl conditions, and to make
! 6: * it not use globals, pollute name space and more. This source code awaits a
! 7: * rewrite to work around the paragraph 2 in the BSD licenses as explained
! 8: * below.
! 9: *
! 10: * Copyright (c) 1998, 1999, 2017 Kungliga Tekniska Högskolan
! 11: * (Royal Institute of Technology, Stockholm, Sweden).
! 12: *
! 13: * Copyright (C) 2001 - 2019, Daniel Stenberg, <daniel@haxx.se>, et al.
! 14: *
! 15: * All rights reserved.
! 16: *
! 17: * Redistribution and use in source and binary forms, with or without
! 18: * modification, are permitted provided that the following conditions
! 19: * are met:
! 20: *
! 21: * 1. Redistributions of source code must retain the above copyright
! 22: * notice, this list of conditions and the following disclaimer.
! 23: *
! 24: * 2. Redistributions in binary form must reproduce the above copyright
! 25: * notice, this list of conditions and the following disclaimer in the
! 26: * documentation and/or other materials provided with the distribution.
! 27: *
! 28: * 3. Neither the name of the Institute nor the names of its contributors
! 29: * may be used to endorse or promote products derived from this software
! 30: * without specific prior written permission.
! 31: *
! 32: * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
! 33: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
! 34: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
! 35: * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
! 36: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
! 37: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
! 38: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
! 39: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
! 40: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
! 41: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
! 42: * SUCH DAMAGE. */
! 43:
! 44: #include "curl_setup.h"
! 45:
! 46: #ifndef CURL_DISABLE_FTP
! 47: #ifdef HAVE_GSSAPI
! 48:
! 49: #ifdef HAVE_NETDB_H
! 50: #include <netdb.h>
! 51: #endif
! 52:
! 53: #include <limits.h>
! 54:
! 55: #include "urldata.h"
! 56: #include "curl_base64.h"
! 57: #include "curl_memory.h"
! 58: #include "curl_sec.h"
! 59: #include "ftp.h"
! 60: #include "sendf.h"
! 61: #include "strcase.h"
! 62: #include "warnless.h"
! 63: #include "strdup.h"
! 64: /* The last 3 #include files should be in this order */
! 65: #include "curl_printf.h"
! 66: #include "curl_memory.h"
! 67: #include "memdebug.h"
! 68:
! 69: static const struct {
! 70: enum protection_level level;
! 71: const char *name;
! 72: } level_names[] = {
! 73: { PROT_CLEAR, "clear" },
! 74: { PROT_SAFE, "safe" },
! 75: { PROT_CONFIDENTIAL, "confidential" },
! 76: { PROT_PRIVATE, "private" }
! 77: };
! 78:
! 79: static enum protection_level
! 80: name_to_level(const char *name)
! 81: {
! 82: int i;
! 83: for(i = 0; i < (int)sizeof(level_names)/(int)sizeof(level_names[0]); i++)
! 84: if(checkprefix(name, level_names[i].name))
! 85: return level_names[i].level;
! 86: return PROT_NONE;
! 87: }
! 88:
! 89: /* Convert a protocol |level| to its char representation.
! 90: We take an int to catch programming mistakes. */
! 91: static char level_to_char(int level)
! 92: {
! 93: switch(level) {
! 94: case PROT_CLEAR:
! 95: return 'C';
! 96: case PROT_SAFE:
! 97: return 'S';
! 98: case PROT_CONFIDENTIAL:
! 99: return 'E';
! 100: case PROT_PRIVATE:
! 101: return 'P';
! 102: case PROT_CMD:
! 103: /* Fall through */
! 104: default:
! 105: /* Those 2 cases should not be reached! */
! 106: break;
! 107: }
! 108: DEBUGASSERT(0);
! 109: /* Default to the most secure alternative. */
! 110: return 'P';
! 111: }
! 112:
! 113: /* Send an FTP command defined by |message| and the optional arguments. The
! 114: function returns the ftp_code. If an error occurs, -1 is returned. */
! 115: static int ftp_send_command(struct connectdata *conn, const char *message, ...)
! 116: {
! 117: int ftp_code;
! 118: ssize_t nread = 0;
! 119: va_list args;
! 120: char print_buffer[50];
! 121:
! 122: va_start(args, message);
! 123: mvsnprintf(print_buffer, sizeof(print_buffer), message, args);
! 124: va_end(args);
! 125:
! 126: if(Curl_ftpsend(conn, print_buffer)) {
! 127: ftp_code = -1;
! 128: }
! 129: else {
! 130: if(Curl_GetFTPResponse(&nread, conn, &ftp_code))
! 131: ftp_code = -1;
! 132: }
! 133:
! 134: (void)nread; /* Unused */
! 135: return ftp_code;
! 136: }
! 137:
! 138: /* Read |len| from the socket |fd| and store it in |to|. Return a CURLcode
! 139: saying whether an error occurred or CURLE_OK if |len| was read. */
! 140: static CURLcode
! 141: socket_read(curl_socket_t fd, void *to, size_t len)
! 142: {
! 143: char *to_p = to;
! 144: CURLcode result;
! 145: ssize_t nread = 0;
! 146:
! 147: while(len > 0) {
! 148: result = Curl_read_plain(fd, to_p, len, &nread);
! 149: if(!result) {
! 150: len -= nread;
! 151: to_p += nread;
! 152: }
! 153: else {
! 154: if(result == CURLE_AGAIN)
! 155: continue;
! 156: return result;
! 157: }
! 158: }
! 159: return CURLE_OK;
! 160: }
! 161:
! 162:
! 163: /* Write |len| bytes from the buffer |to| to the socket |fd|. Return a
! 164: CURLcode saying whether an error occurred or CURLE_OK if |len| was
! 165: written. */
! 166: static CURLcode
! 167: socket_write(struct connectdata *conn, curl_socket_t fd, const void *to,
! 168: size_t len)
! 169: {
! 170: const char *to_p = to;
! 171: CURLcode result;
! 172: ssize_t written;
! 173:
! 174: while(len > 0) {
! 175: result = Curl_write_plain(conn, fd, to_p, len, &written);
! 176: if(!result) {
! 177: len -= written;
! 178: to_p += written;
! 179: }
! 180: else {
! 181: if(result == CURLE_AGAIN)
! 182: continue;
! 183: return result;
! 184: }
! 185: }
! 186: return CURLE_OK;
! 187: }
! 188:
! 189: static CURLcode read_data(struct connectdata *conn,
! 190: curl_socket_t fd,
! 191: struct krb5buffer *buf)
! 192: {
! 193: int len;
! 194: CURLcode result;
! 195:
! 196: result = socket_read(fd, &len, sizeof(len));
! 197: if(result)
! 198: return result;
! 199:
! 200: if(len) {
! 201: /* only realloc if there was a length */
! 202: len = ntohl(len);
! 203: buf->data = Curl_saferealloc(buf->data, len);
! 204: }
! 205: if(!len || !buf->data)
! 206: return CURLE_OUT_OF_MEMORY;
! 207:
! 208: result = socket_read(fd, buf->data, len);
! 209: if(result)
! 210: return result;
! 211: buf->size = conn->mech->decode(conn->app_data, buf->data, len,
! 212: conn->data_prot, conn);
! 213: buf->index = 0;
! 214: return CURLE_OK;
! 215: }
! 216:
! 217: static size_t
! 218: buffer_read(struct krb5buffer *buf, void *data, size_t len)
! 219: {
! 220: if(buf->size - buf->index < len)
! 221: len = buf->size - buf->index;
! 222: memcpy(data, (char *)buf->data + buf->index, len);
! 223: buf->index += len;
! 224: return len;
! 225: }
! 226:
! 227: /* Matches Curl_recv signature */
! 228: static ssize_t sec_recv(struct connectdata *conn, int sockindex,
! 229: char *buffer, size_t len, CURLcode *err)
! 230: {
! 231: size_t bytes_read;
! 232: size_t total_read = 0;
! 233: curl_socket_t fd = conn->sock[sockindex];
! 234:
! 235: *err = CURLE_OK;
! 236:
! 237: /* Handle clear text response. */
! 238: if(conn->sec_complete == 0 || conn->data_prot == PROT_CLEAR)
! 239: return sread(fd, buffer, len);
! 240:
! 241: if(conn->in_buffer.eof_flag) {
! 242: conn->in_buffer.eof_flag = 0;
! 243: return 0;
! 244: }
! 245:
! 246: bytes_read = buffer_read(&conn->in_buffer, buffer, len);
! 247: len -= bytes_read;
! 248: total_read += bytes_read;
! 249: buffer += bytes_read;
! 250:
! 251: while(len > 0) {
! 252: if(read_data(conn, fd, &conn->in_buffer))
! 253: return -1;
! 254: if(conn->in_buffer.size == 0) {
! 255: if(bytes_read > 0)
! 256: conn->in_buffer.eof_flag = 1;
! 257: return bytes_read;
! 258: }
! 259: bytes_read = buffer_read(&conn->in_buffer, buffer, len);
! 260: len -= bytes_read;
! 261: total_read += bytes_read;
! 262: buffer += bytes_read;
! 263: }
! 264: return total_read;
! 265: }
! 266:
! 267: /* Send |length| bytes from |from| to the |fd| socket taking care of encoding
! 268: and negotiating with the server. |from| can be NULL. */
! 269: static void do_sec_send(struct connectdata *conn, curl_socket_t fd,
! 270: const char *from, int length)
! 271: {
! 272: int bytes, htonl_bytes; /* 32-bit integers for htonl */
! 273: char *buffer = NULL;
! 274: char *cmd_buffer;
! 275: size_t cmd_size = 0;
! 276: CURLcode error;
! 277: enum protection_level prot_level = conn->data_prot;
! 278: bool iscmd = (prot_level == PROT_CMD)?TRUE:FALSE;
! 279:
! 280: DEBUGASSERT(prot_level > PROT_NONE && prot_level < PROT_LAST);
! 281:
! 282: if(iscmd) {
! 283: if(!strncmp(from, "PASS ", 5) || !strncmp(from, "ACCT ", 5))
! 284: prot_level = PROT_PRIVATE;
! 285: else
! 286: prot_level = conn->command_prot;
! 287: }
! 288: bytes = conn->mech->encode(conn->app_data, from, length, prot_level,
! 289: (void **)&buffer);
! 290: if(!buffer || bytes <= 0)
! 291: return; /* error */
! 292:
! 293: if(iscmd) {
! 294: error = Curl_base64_encode(conn->data, buffer, curlx_sitouz(bytes),
! 295: &cmd_buffer, &cmd_size);
! 296: if(error) {
! 297: free(buffer);
! 298: return; /* error */
! 299: }
! 300: if(cmd_size > 0) {
! 301: static const char *enc = "ENC ";
! 302: static const char *mic = "MIC ";
! 303: if(prot_level == PROT_PRIVATE)
! 304: socket_write(conn, fd, enc, 4);
! 305: else
! 306: socket_write(conn, fd, mic, 4);
! 307:
! 308: socket_write(conn, fd, cmd_buffer, cmd_size);
! 309: socket_write(conn, fd, "\r\n", 2);
! 310: infof(conn->data, "Send: %s%s\n", prot_level == PROT_PRIVATE?enc:mic,
! 311: cmd_buffer);
! 312: free(cmd_buffer);
! 313: }
! 314: }
! 315: else {
! 316: htonl_bytes = htonl(bytes);
! 317: socket_write(conn, fd, &htonl_bytes, sizeof(htonl_bytes));
! 318: socket_write(conn, fd, buffer, curlx_sitouz(bytes));
! 319: }
! 320: free(buffer);
! 321: }
! 322:
! 323: static ssize_t sec_write(struct connectdata *conn, curl_socket_t fd,
! 324: const char *buffer, size_t length)
! 325: {
! 326: ssize_t tx = 0, len = conn->buffer_size;
! 327:
! 328: len -= conn->mech->overhead(conn->app_data, conn->data_prot,
! 329: curlx_sztosi(len));
! 330: if(len <= 0)
! 331: len = length;
! 332: while(length) {
! 333: if(length < (size_t)len)
! 334: len = length;
! 335:
! 336: do_sec_send(conn, fd, buffer, curlx_sztosi(len));
! 337: length -= len;
! 338: buffer += len;
! 339: tx += len;
! 340: }
! 341: return tx;
! 342: }
! 343:
! 344: /* Matches Curl_send signature */
! 345: static ssize_t sec_send(struct connectdata *conn, int sockindex,
! 346: const void *buffer, size_t len, CURLcode *err)
! 347: {
! 348: curl_socket_t fd = conn->sock[sockindex];
! 349: *err = CURLE_OK;
! 350: return sec_write(conn, fd, buffer, len);
! 351: }
! 352:
! 353: int Curl_sec_read_msg(struct connectdata *conn, char *buffer,
! 354: enum protection_level level)
! 355: {
! 356: /* decoded_len should be size_t or ssize_t but conn->mech->decode returns an
! 357: int */
! 358: int decoded_len;
! 359: char *buf;
! 360: int ret_code = 0;
! 361: size_t decoded_sz = 0;
! 362: CURLcode error;
! 363:
! 364: if(!conn->mech)
! 365: /* not inititalized, return error */
! 366: return -1;
! 367:
! 368: DEBUGASSERT(level > PROT_NONE && level < PROT_LAST);
! 369:
! 370: error = Curl_base64_decode(buffer + 4, (unsigned char **)&buf, &decoded_sz);
! 371: if(error || decoded_sz == 0)
! 372: return -1;
! 373:
! 374: if(decoded_sz > (size_t)INT_MAX) {
! 375: free(buf);
! 376: return -1;
! 377: }
! 378: decoded_len = curlx_uztosi(decoded_sz);
! 379:
! 380: decoded_len = conn->mech->decode(conn->app_data, buf, decoded_len,
! 381: level, conn);
! 382: if(decoded_len <= 0) {
! 383: free(buf);
! 384: return -1;
! 385: }
! 386:
! 387: if(conn->data->set.verbose) {
! 388: buf[decoded_len] = '\n';
! 389: Curl_debug(conn->data, CURLINFO_HEADER_IN, buf, decoded_len + 1);
! 390: }
! 391:
! 392: buf[decoded_len] = '\0';
! 393: if(decoded_len <= 3)
! 394: /* suspiciously short */
! 395: return 0;
! 396:
! 397: if(buf[3] != '-')
! 398: /* safe to ignore return code */
! 399: (void)sscanf(buf, "%d", &ret_code);
! 400:
! 401: if(buf[decoded_len - 1] == '\n')
! 402: buf[decoded_len - 1] = '\0';
! 403: strcpy(buffer, buf);
! 404: free(buf);
! 405: return ret_code;
! 406: }
! 407:
! 408: static int sec_set_protection_level(struct connectdata *conn)
! 409: {
! 410: int code;
! 411: enum protection_level level = conn->request_data_prot;
! 412:
! 413: DEBUGASSERT(level > PROT_NONE && level < PROT_LAST);
! 414:
! 415: if(!conn->sec_complete) {
! 416: infof(conn->data, "Trying to change the protection level after the"
! 417: " completion of the data exchange.\n");
! 418: return -1;
! 419: }
! 420:
! 421: /* Bail out if we try to set up the same level */
! 422: if(conn->data_prot == level)
! 423: return 0;
! 424:
! 425: if(level) {
! 426: char *pbsz;
! 427: static unsigned int buffer_size = 1 << 20; /* 1048576 */
! 428:
! 429: code = ftp_send_command(conn, "PBSZ %u", buffer_size);
! 430: if(code < 0)
! 431: return -1;
! 432:
! 433: if(code/100 != 2) {
! 434: failf(conn->data, "Failed to set the protection's buffer size.");
! 435: return -1;
! 436: }
! 437: conn->buffer_size = buffer_size;
! 438:
! 439: pbsz = strstr(conn->data->state.buffer, "PBSZ=");
! 440: if(pbsz) {
! 441: /* ignore return code, use default value if it fails */
! 442: (void)sscanf(pbsz, "PBSZ=%u", &buffer_size);
! 443: if(buffer_size < conn->buffer_size)
! 444: conn->buffer_size = buffer_size;
! 445: }
! 446: }
! 447:
! 448: /* Now try to negiociate the protection level. */
! 449: code = ftp_send_command(conn, "PROT %c", level_to_char(level));
! 450:
! 451: if(code < 0)
! 452: return -1;
! 453:
! 454: if(code/100 != 2) {
! 455: failf(conn->data, "Failed to set the protection level.");
! 456: return -1;
! 457: }
! 458:
! 459: conn->data_prot = level;
! 460: if(level == PROT_PRIVATE)
! 461: conn->command_prot = level;
! 462:
! 463: return 0;
! 464: }
! 465:
! 466: int
! 467: Curl_sec_request_prot(struct connectdata *conn, const char *level)
! 468: {
! 469: enum protection_level l = name_to_level(level);
! 470: if(l == PROT_NONE)
! 471: return -1;
! 472: DEBUGASSERT(l > PROT_NONE && l < PROT_LAST);
! 473: conn->request_data_prot = l;
! 474: return 0;
! 475: }
! 476:
! 477: static CURLcode choose_mech(struct connectdata *conn)
! 478: {
! 479: int ret;
! 480: struct Curl_easy *data = conn->data;
! 481: void *tmp_allocation;
! 482: const struct Curl_sec_client_mech *mech = &Curl_krb5_client_mech;
! 483:
! 484: tmp_allocation = realloc(conn->app_data, mech->size);
! 485: if(tmp_allocation == NULL) {
! 486: failf(data, "Failed realloc of size %zu", mech->size);
! 487: mech = NULL;
! 488: return CURLE_OUT_OF_MEMORY;
! 489: }
! 490: conn->app_data = tmp_allocation;
! 491:
! 492: if(mech->init) {
! 493: ret = mech->init(conn->app_data);
! 494: if(ret) {
! 495: infof(data, "Failed initialization for %s. Skipping it.\n",
! 496: mech->name);
! 497: return CURLE_FAILED_INIT;
! 498: }
! 499: }
! 500:
! 501: infof(data, "Trying mechanism %s...\n", mech->name);
! 502: ret = ftp_send_command(conn, "AUTH %s", mech->name);
! 503: if(ret < 0)
! 504: return CURLE_COULDNT_CONNECT;
! 505:
! 506: if(ret/100 != 3) {
! 507: switch(ret) {
! 508: case 504:
! 509: infof(data, "Mechanism %s is not supported by the server (server "
! 510: "returned ftp code: 504).\n", mech->name);
! 511: break;
! 512: case 534:
! 513: infof(data, "Mechanism %s was rejected by the server (server returned "
! 514: "ftp code: 534).\n", mech->name);
! 515: break;
! 516: default:
! 517: if(ret/100 == 5) {
! 518: infof(data, "server does not support the security extensions\n");
! 519: return CURLE_USE_SSL_FAILED;
! 520: }
! 521: break;
! 522: }
! 523: return CURLE_LOGIN_DENIED;
! 524: }
! 525:
! 526: /* Authenticate */
! 527: ret = mech->auth(conn->app_data, conn);
! 528:
! 529: if(ret != AUTH_CONTINUE) {
! 530: if(ret != AUTH_OK) {
! 531: /* Mechanism has dumped the error to stderr, don't error here. */
! 532: return -1;
! 533: }
! 534: DEBUGASSERT(ret == AUTH_OK);
! 535:
! 536: conn->mech = mech;
! 537: conn->sec_complete = 1;
! 538: conn->recv[FIRSTSOCKET] = sec_recv;
! 539: conn->send[FIRSTSOCKET] = sec_send;
! 540: conn->recv[SECONDARYSOCKET] = sec_recv;
! 541: conn->send[SECONDARYSOCKET] = sec_send;
! 542: conn->command_prot = PROT_SAFE;
! 543: /* Set the requested protection level */
! 544: /* BLOCKING */
! 545: (void)sec_set_protection_level(conn);
! 546: }
! 547:
! 548: return CURLE_OK;
! 549: }
! 550:
! 551: CURLcode
! 552: Curl_sec_login(struct connectdata *conn)
! 553: {
! 554: return choose_mech(conn);
! 555: }
! 556:
! 557:
! 558: void
! 559: Curl_sec_end(struct connectdata *conn)
! 560: {
! 561: if(conn->mech != NULL && conn->mech->end)
! 562: conn->mech->end(conn->app_data);
! 563: free(conn->app_data);
! 564: conn->app_data = NULL;
! 565: if(conn->in_buffer.data) {
! 566: free(conn->in_buffer.data);
! 567: conn->in_buffer.data = NULL;
! 568: conn->in_buffer.size = 0;
! 569: conn->in_buffer.index = 0;
! 570: conn->in_buffer.eof_flag = 0;
! 571: }
! 572: conn->sec_complete = 0;
! 573: conn->data_prot = PROT_CLEAR;
! 574: conn->mech = NULL;
! 575: }
! 576:
! 577: #endif /* HAVE_GSSAPI */
! 578:
! 579: #endif /* CURL_DISABLE_FTP */
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