usr.sbin/ctld/login.c

   1 /*-
   2  * Copyright (c) 2012 The FreeBSD Foundation
   3  * All rights reserved.
   4  *
   5  * This software was developed by Edward Tomasz Napierala under sponsorship
   6  * from the FreeBSD Foundation.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  */
  30
  31 #include <sys/cdefs.h>
  32 __FBSDID("$FreeBSD$");
  33
  34 #include <assert.h>
  35 #include <stdbool.h>
  36 #include <stdint.h>
  37 #include <stdio.h>
  38 #include <stdlib.h>
  39 #include <string.h>
  40 #include <unistd.h>
  41 #include <netinet/in.h>
  42 #include <openssl/err.h>
  43 #include <openssl/md5.h>
  44 #include <openssl/rand.h>
  45
  46 #include "ctld.h"
  47 #include "iscsi_proto.h"
  48
  49 static void login_send_error(struct pdu *request,
  50     char class, char detail);
  51
  52 static void
  53 login_set_nsg(struct pdu *response, int nsg)
  54 {
  55         struct iscsi_bhs_login_response *bhslr;
  56
  57         assert(nsg == BHSLR_STAGE_SECURITY_NEGOTIATION ||
  58             nsg == BHSLR_STAGE_OPERATIONAL_NEGOTIATION ||
  59             nsg == BHSLR_STAGE_FULL_FEATURE_PHASE);
  60
  61         bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
  62
  63         bhslr->bhslr_flags &= 0xFC;
  64         bhslr->bhslr_flags |= nsg;
  65 }
  66
  67 static int
  68 login_csg(const struct pdu *request)
  69 {
  70         struct iscsi_bhs_login_request *bhslr;
  71
  72         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
  73
  74         return ((bhslr->bhslr_flags & 0x0C) >> 2);
  75 }
  76
  77 static void
  78 login_set_csg(struct pdu *response, int csg)
  79 {
  80         struct iscsi_bhs_login_response *bhslr;
  81
  82         assert(csg == BHSLR_STAGE_SECURITY_NEGOTIATION ||
  83             csg == BHSLR_STAGE_OPERATIONAL_NEGOTIATION ||
  84             csg == BHSLR_STAGE_FULL_FEATURE_PHASE);
  85
  86         bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
  87
  88         bhslr->bhslr_flags &= 0xF3;
  89         bhslr->bhslr_flags |= csg << 2;
  90 }
  91
  92 static struct pdu *
  93 login_receive(struct connection *conn, bool initial)
  94 {
  95         struct pdu *request;
  96         struct iscsi_bhs_login_request *bhslr;
  97
  98         request = pdu_new(conn);
  99         pdu_receive(request);
 100         if ((request->pdu_bhs->bhs_opcode & ~ISCSI_BHS_OPCODE_IMMEDIATE) !=
 101             ISCSI_BHS_OPCODE_LOGIN_REQUEST) {
 102                 /*
 103                  * The first PDU in session is special - if we receive any PDU
 104                  * different than login request, we have to drop the connection
 105                  * without sending response ("A target receiving any PDU
 106                  * except a Login request before the Login Phase is started MUST
 107                  * immediately terminate the connection on which the PDU
 108                  * was received.")
 109                  */
 110                 if (initial == false)
 111                         login_send_error(request, 0x02, 0x0b);
 112                 log_errx(1, "protocol error: received invalid opcode 0x%x",
 113                     request->pdu_bhs->bhs_opcode);
 114         }
 115         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
 116         /*
 117          * XXX: Implement the C flag some day.
 118          */
 119         if ((bhslr->bhslr_flags & BHSLR_FLAGS_CONTINUE) != 0) {
 120                 login_send_error(request, 0x03, 0x00);
 121                 log_errx(1, "received Login PDU with unsupported \"C\" flag");
 122         }
 123         if (bhslr->bhslr_version_max != 0x00) {
 124                 login_send_error(request, 0x02, 0x05);
 125                 log_errx(1, "received Login PDU with unsupported "
 126                     "Version-max 0x%x", bhslr->bhslr_version_max);
 127         }
 128         if (bhslr->bhslr_version_min != 0x00) {
 129                 login_send_error(request, 0x02, 0x05);
 130                 log_errx(1, "received Login PDU with unsupported "
 131                     "Version-min 0x%x", bhslr->bhslr_version_min);
 132         }
 133         if (ntohl(bhslr->bhslr_cmdsn) < conn->conn_cmdsn) {
 134                 login_send_error(request, 0x02, 0x05);
 135                 log_errx(1, "received Login PDU with decreasing CmdSN: "
 136                     "was %d, is %d", conn->conn_cmdsn,
 137                     ntohl(bhslr->bhslr_cmdsn));
 138         }
 139         if (initial == false &&
 140             ntohl(bhslr->bhslr_expstatsn) != conn->conn_statsn) {
 141                 login_send_error(request, 0x02, 0x05);
 142                 log_errx(1, "received Login PDU with wrong ExpStatSN: "
 143                     "is %d, should be %d", ntohl(bhslr->bhslr_expstatsn),
 144                     conn->conn_statsn);
 145         }
 146         conn->conn_cmdsn = ntohl(bhslr->bhslr_cmdsn);
 147
 148         return (request);
 149 }
 150
 151 static struct pdu *
 152 login_new_response(struct pdu *request)
 153 {
 154         struct pdu *response;
 155         struct connection *conn;
 156         struct iscsi_bhs_login_request *bhslr;
 157         struct iscsi_bhs_login_response *bhslr2;
 158
 159         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
 160         conn = request->pdu_connection;
 161
 162         response = pdu_new_response(request);
 163         bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 164         bhslr2->bhslr_opcode = ISCSI_BHS_OPCODE_LOGIN_RESPONSE;
 165         login_set_csg(response, BHSLR_STAGE_SECURITY_NEGOTIATION);
 166         memcpy(bhslr2->bhslr_isid,
 167             bhslr->bhslr_isid, sizeof(bhslr2->bhslr_isid));
 168         bhslr2->bhslr_initiator_task_tag = bhslr->bhslr_initiator_task_tag;
 169         bhslr2->bhslr_statsn = htonl(conn->conn_statsn++);
 170         bhslr2->bhslr_expcmdsn = htonl(conn->conn_cmdsn);
 171         bhslr2->bhslr_maxcmdsn = htonl(conn->conn_cmdsn);
 172
 173         return (response);
 174 }
 175
 176 static void
 177 login_send_error(struct pdu *request, char class, char detail)
 178 {
 179         struct pdu *response;
 180         struct iscsi_bhs_login_response *bhslr2;
 181
 182         log_debugx("sending Login Response PDU with failure class 0x%x/0x%x; "
 183             "see next line for reason", class, detail);
 184         response = login_new_response(request);
 185         bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 186         bhslr2->bhslr_status_class = class;
 187         bhslr2->bhslr_status_detail = detail;
 188
 189         pdu_send(response);
 190         pdu_delete(response);
 191 }
 192
 193 static int
 194 login_list_contains(const char *list, const char *what)
 195 {
 196         char *tofree, *str, *token;
 197
 198         tofree = str = checked_strdup(list);
 199
 200         while ((token = strsep(&str, ",")) != NULL) {
 201                 if (strcmp(token, what) == 0) {
 202                         free(tofree);
 203                         return (1);
 204                 }
 205         }
 206         free(tofree);
 207         return (0);
 208 }
 209
 210 static int
 211 login_list_prefers(const char *list,
 212     const char *choice1, const char *choice2)
 213 {
 214         char *tofree, *str, *token;
 215
 216         tofree = str = checked_strdup(list);
 217
 218         while ((token = strsep(&str, ",")) != NULL) {
 219                 if (strcmp(token, choice1) == 0) {
 220                         free(tofree);
 221                         return (1);
 222                 }
 223                 if (strcmp(token, choice2) == 0) {
 224                         free(tofree);
 225                         return (2);
 226                 }
 227         }
 228         free(tofree);
 229         return (-1);
 230 }
 231
 232 static int
 233 login_hex2int(const char hex)
 234 {
 235         switch (hex) {
 236         case '0':
 237                 return (0x00);
 238         case '1':
 239                 return (0x01);
 240         case '2':
 241                 return (0x02);
 242         case '3':
 243                 return (0x03);
 244         case '4':
 245                 return (0x04);
 246         case '5':
 247                 return (0x05);
 248         case '6':
 249                 return (0x06);
 250         case '7':
 251                 return (0x07);
 252         case '8':
 253                 return (0x08);
 254         case '9':
 255                 return (0x09);
 256         case 'a':
 257         case 'A':
 258                 return (0x0a);
 259         case 'b':
 260         case 'B':
 261                 return (0x0b);
 262         case 'c':
 263         case 'C':
 264                 return (0x0c);
 265         case 'd':
 266         case 'D':
 267                 return (0x0d);
 268         case 'e':
 269         case 'E':
 270                 return (0x0e);
 271         case 'f':
 272         case 'F':
 273                 return (0x0f);
 274         default:
 275                 return (-1);
 276         }
 277 }
 278
 279 /*
 280  * XXX: Review this _carefully_.
 281  */
 282 static int
 283 login_hex2bin(const char *hex, char **binp, size_t *bin_lenp)
 284 {
 285         int i, hex_len, nibble;
 286         bool lo = true; /* As opposed to 'hi'. */
 287         char *bin;
 288         size_t bin_off, bin_len;
 289
 290         if (strncasecmp(hex, "0x", strlen("0x")) != 0) {
 291                 log_warnx("malformed variable, should start with \"0x\"");
 292                 return (-1);
 293         }
 294
 295         hex += strlen("0x");
 296         hex_len = strlen(hex);
 297         if (hex_len < 1) {
 298                 log_warnx("malformed variable; doesn't contain anything "
 299                     "but \"0x\"");
 300                 return (-1);
 301         }
 302
 303         bin_len = hex_len / 2 + hex_len % 2;
 304         bin = calloc(bin_len, 1);
 305         if (bin == NULL)
 306                 log_err(1, "calloc");
 307
 308         bin_off = bin_len - 1;
 309         for (i = hex_len - 1; i >= 0; i--) {
 310                 nibble = login_hex2int(hex[i]);
 311                 if (nibble < 0) {
 312                         log_warnx("malformed variable, invalid char \"%c\"",
 313                             hex[i]);
 314                         return (-1);
 315                 }
 316
 317                 assert(bin_off < bin_len);
 318                 if (lo) {
 319                         bin[bin_off] = nibble;
 320                         lo = false;
 321                 } else {
 322                         bin[bin_off] |= nibble << 4;
 323                         bin_off--;
 324                         lo = true;
 325                 }
 326         }
 327
 328         *binp = bin;
 329         *bin_lenp = bin_len;
 330         return (0);
 331 }
 332
 333 static char *
 334 login_bin2hex(const char *bin, size_t bin_len)
 335 {
 336         unsigned char *hex, *tmp, ch;
 337         size_t hex_len;
 338         size_t i;
 339
 340         hex_len = bin_len * 2 + 3; /* +2 for "0x", +1 for '\0'. */
 341         hex = malloc(hex_len);
 342         if (hex == NULL)
 343                 log_err(1, "malloc");
 344
 345         tmp = hex;
 346         tmp += sprintf(tmp, "0x");
 347         for (i = 0; i < bin_len; i++) {
 348                 ch = bin[i];
 349                 tmp += sprintf(tmp, "%02x", ch);
 350         }
 351
 352         return (hex);
 353 }
 354
 355 static void
 356 login_compute_md5(const char id, const char *secret,
 357     const void *challenge, size_t challenge_len, void *response,
 358     size_t response_len)
 359 {
 360         MD5_CTX ctx;
 361         int rv;
 362
 363         assert(response_len == MD5_DIGEST_LENGTH);
 364
 365         MD5_Init(&ctx);
 366         MD5_Update(&ctx, &id, sizeof(id));
 367         MD5_Update(&ctx, secret, strlen(secret));
 368         MD5_Update(&ctx, challenge, challenge_len);
 369         rv = MD5_Final(response, &ctx);
 370         if (rv != 1)
 371                 log_errx(1, "MD5_Final");
 372 }
 373
 374 #define LOGIN_CHALLENGE_LEN     1024
 375
 376 static struct pdu *
 377 login_receive_chap_a(struct connection *conn)
 378 {
 379         struct pdu *request;
 380         struct keys *request_keys;
 381         const char *chap_a;
 382
 383         request = login_receive(conn, false);
 384         request_keys = keys_new();
 385         keys_load(request_keys, request);
 386
 387         chap_a = keys_find(request_keys, "CHAP_A");
 388         if (chap_a == NULL) {
 389                 login_send_error(request, 0x02, 0x07);
 390                 log_errx(1, "received CHAP Login PDU without CHAP_A");
 391         }
 392         if (login_list_contains(chap_a, "5") == 0) {
 393                 login_send_error(request, 0x02, 0x01);
 394                 log_errx(1, "received CHAP Login PDU with unsupported CHAP_A "
 395                     "\"%s\"", chap_a);
 396         }
 397         keys_delete(request_keys);
 398
 399         return (request);
 400 }
 401
 402 static void
 403 login_send_chap_c(struct pdu *request, const unsigned char id,
 404     const void *challenge, const size_t challenge_len)
 405 {
 406         struct pdu *response;
 407         struct keys *response_keys;
 408         char *chap_c, chap_i[4];
 409
 410         chap_c = login_bin2hex(challenge, challenge_len);
 411         snprintf(chap_i, sizeof(chap_i), "%d", id);
 412
 413         response = login_new_response(request);
 414         response_keys = keys_new();
 415         keys_add(response_keys, "CHAP_A", "5");
 416         keys_add(response_keys, "CHAP_I", chap_i);
 417         keys_add(response_keys, "CHAP_C", chap_c);
 418         free(chap_c);
 419         keys_save(response_keys, response);
 420         pdu_send(response);
 421         pdu_delete(response);
 422         keys_delete(response_keys);
 423 }
 424
 425 static struct pdu *
 426 login_receive_chap_r(struct connection *conn,
 427     struct auth_group *ag, const unsigned char id, const void *challenge,
 428     const size_t challenge_len, const struct auth **cap)
 429 {
 430         struct pdu *request;
 431         struct keys *request_keys;
 432         const char *chap_n, *chap_r;
 433         char *response_bin, expected_response_bin[MD5_DIGEST_LENGTH];
 434         size_t response_bin_len;
 435         const struct auth *auth;
 436         int error;
 437
 438         request = login_receive(conn, false);
 439         request_keys = keys_new();
 440         keys_load(request_keys, request);
 441
 442         chap_n = keys_find(request_keys, "CHAP_N");
 443         if (chap_n == NULL) {
 444                 login_send_error(request, 0x02, 0x07);
 445                 log_errx(1, "received CHAP Login PDU without CHAP_N");
 446         }
 447         chap_r = keys_find(request_keys, "CHAP_R");
 448         if (chap_r == NULL) {
 449                 login_send_error(request, 0x02, 0x07);
 450                 log_errx(1, "received CHAP Login PDU without CHAP_R");
 451         }
 452         error = login_hex2bin(chap_r, &response_bin, &response_bin_len);
 453         if (error != 0) {
 454                 login_send_error(request, 0x02, 0x07);
 455                 log_errx(1, "received CHAP Login PDU with malformed CHAP_R");
 456         }
 457
 458         /*
 459          * Verify the response.
 460          */
 461         assert(ag->ag_type == AG_TYPE_CHAP ||
 462             ag->ag_type == AG_TYPE_CHAP_MUTUAL);
 463         auth = auth_find(ag, chap_n);
 464         if (auth == NULL) {
 465                 login_send_error(request, 0x02, 0x01);
 466                 log_errx(1, "received CHAP Login with invalid user \"%s\"",
 467                     chap_n);
 468         }
 469
 470         assert(auth->a_secret != NULL);
 471         assert(strlen(auth->a_secret) > 0);
 472         login_compute_md5(id, auth->a_secret, challenge,
 473             challenge_len, expected_response_bin,
 474             sizeof(expected_response_bin));
 475
 476         if (memcmp(response_bin, expected_response_bin,
 477             sizeof(expected_response_bin)) != 0) {
 478                 login_send_error(request, 0x02, 0x01);
 479                 log_errx(1, "CHAP authentication failed for user \"%s\"",
 480                     auth->a_user);
 481         }
 482
 483         keys_delete(request_keys);
 484         free(response_bin);
 485
 486         *cap = auth;
 487         return (request);
 488 }
 489
 490 static void
 491 login_send_chap_success(struct pdu *request,
 492     const struct auth *auth)
 493 {
 494         struct pdu *response;
 495         struct keys *request_keys, *response_keys;
 496         struct iscsi_bhs_login_response *bhslr2;
 497         const char *chap_i, *chap_c;
 498         char *chap_r, *challenge, response_bin[MD5_DIGEST_LENGTH];
 499         size_t challenge_len;
 500         unsigned char id;
 501         int error;
 502
 503         response = login_new_response(request);
 504         bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 505         bhslr2->bhslr_flags |= BHSLR_FLAGS_TRANSIT;
 506         login_set_nsg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
 507
 508         /*
 509          * Actually, one more thing: mutual authentication.
 510          */
 511         request_keys = keys_new();
 512         keys_load(request_keys, request);
 513         chap_i = keys_find(request_keys, "CHAP_I");
 514         chap_c = keys_find(request_keys, "CHAP_C");
 515         if (chap_i != NULL || chap_c != NULL) {
 516                 if (chap_i == NULL) {
 517                         login_send_error(request, 0x02, 0x07);
 518                         log_errx(1, "initiator requested target "
 519                             "authentication, but didn't send CHAP_I");
 520                 }
 521                 if (chap_c == NULL) {
 522                         login_send_error(request, 0x02, 0x07);
 523                         log_errx(1, "initiator requested target "
 524                             "authentication, but didn't send CHAP_C");
 525                 }
 526                 if (auth->a_auth_group->ag_type != AG_TYPE_CHAP_MUTUAL) {
 527                         login_send_error(request, 0x02, 0x01);
 528                         log_errx(1, "initiator requests target authentication "
 529                             "for user \"%s\", but mutual user/secret "
 530                             "is not set", auth->a_user);
 531                 }
 532
 533                 id = strtoul(chap_i, NULL, 10);
 534                 error = login_hex2bin(chap_c, &challenge, &challenge_len);
 535                 if (error != 0) {
 536                         login_send_error(request, 0x02, 0x07);
 537                         log_errx(1, "received CHAP Login PDU with malformed "
 538                             "CHAP_C");
 539                 }
 540
 541                 log_debugx("performing mutual authentication as user \"%s\"",
 542                     auth->a_mutual_user);
 543                 login_compute_md5(id, auth->a_mutual_secret, challenge,
 544                     challenge_len, response_bin, sizeof(response_bin));
 545
 546                 chap_r = login_bin2hex(response_bin,
 547                     sizeof(response_bin));
 548                 response_keys = keys_new();
 549                 keys_add(response_keys, "CHAP_N", auth->a_mutual_user);
 550                 keys_add(response_keys, "CHAP_R", chap_r);
 551                 free(chap_r);
 552                 keys_save(response_keys, response);
 553                 keys_delete(response_keys);
 554         } else {
 555                 log_debugx("initiator did not request target authentication");
 556         }
 557
 558         keys_delete(request_keys);
 559         pdu_send(response);
 560         pdu_delete(response);
 561 }
 562
 563 static void
 564 login_chap(struct connection *conn, struct auth_group *ag)
 565 {
 566         const struct auth *auth;
 567         struct pdu *request;
 568         char challenge_bin[LOGIN_CHALLENGE_LEN];
 569         unsigned char id;
 570         int rv;
 571
 572         /*
 573          * Receive CHAP_A PDU.
 574          */
 575         log_debugx("beginning CHAP authentication; waiting for CHAP_A");
 576         request = login_receive_chap_a(conn);
 577
 578         /*
 579          * Generate the challenge.
 580          */
 581         rv = RAND_bytes(challenge_bin, sizeof(challenge_bin));
 582         if (rv != 1) {
 583                 login_send_error(request, 0x03, 0x02);
 584                 log_errx(1, "RAND_bytes failed: %s",
 585                     ERR_error_string(ERR_get_error(), NULL));
 586         }
 587         rv = RAND_bytes(&id, sizeof(id));
 588         if (rv != 1) {
 589                 login_send_error(request, 0x03, 0x02);
 590                 log_errx(1, "RAND_bytes failed: %s",
 591                     ERR_error_string(ERR_get_error(), NULL));
 592         }
 593
 594         /*
 595          * Send the challenge.
 596          */
 597         log_debugx("sending CHAP_C, binary challenge size is %zd bytes",
 598             sizeof(challenge_bin));
 599         login_send_chap_c(request, id, challenge_bin,
 600             sizeof(challenge_bin));
 601         pdu_delete(request);
 602
 603         /*
 604          * Receive CHAP_N/CHAP_R PDU and authenticate.
 605          */
 606         log_debugx("waiting for CHAP_N/CHAP_R");
 607         request = login_receive_chap_r(conn, ag, id, challenge_bin,
 608             sizeof(challenge_bin), &auth);
 609
 610         /*
 611          * Yay, authentication succeeded!
 612          */
 613         log_debugx("authentication succeeded for user \"%s\"; "
 614             "transitioning to Negotiation Phase", auth->a_user);
 615         login_send_chap_success(request, auth);
 616         pdu_delete(request);
 617 }
 618
 619 static void
 620 login_negotiate_key(struct pdu *request, const char *name,
 621     const char *value, bool skipped_security, struct keys *response_keys)
 622 {
 623         int which, tmp;
 624         struct connection *conn;
 625
 626         conn = request->pdu_connection;
 627
 628         if (strcmp(name, "InitiatorName") == 0) {
 629                 if (!skipped_security)
 630                         log_errx(1, "initiator resent InitiatorName");
 631         } else if (strcmp(name, "SessionType") == 0) {
 632                 if (!skipped_security)
 633                         log_errx(1, "initiator resent SessionType");
 634         } else if (strcmp(name, "TargetName") == 0) {
 635                 if (!skipped_security)
 636                         log_errx(1, "initiator resent TargetName");
 637         } else if (strcmp(name, "InitiatorAlias") == 0) {
 638                 if (conn->conn_initiator_alias != NULL)
 639                         free(conn->conn_initiator_alias);
 640                 conn->conn_initiator_alias = checked_strdup(value);
 641         } else if (strcmp(value, "Irrelevant") == 0) {
 642                 /* Ignore. */
 643         } else if (strcmp(name, "HeaderDigest") == 0) {
 644                 /*
 645                  * We don't handle digests for discovery sessions.
 646                  */
 647                 if (conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY) {
 648                         log_debugx("discovery session; digests disabled");
 649                         keys_add(response_keys, name, "None");
 650                         return;
 651                 }
 652
 653                 which = login_list_prefers(value, "CRC32C", "None");
 654                 switch (which) {
 655                 case 1:
 656                         log_debugx("initiator prefers CRC32C "
 657                             "for header digest; we'll use it");
 658                         conn->conn_header_digest = CONN_DIGEST_CRC32C;
 659                         keys_add(response_keys, name, "CRC32C");
 660                         break;
 661                 case 2:
 662                         log_debugx("initiator prefers not to do "
 663                             "header digest; we'll comply");
 664                         keys_add(response_keys, name, "None");
 665                         break;
 666                 default:
 667                         log_warnx("initiator sent unrecognized "
 668                             "HeaderDigest value \"%s\"; will use None", value);
 669                         keys_add(response_keys, name, "None");
 670                         break;
 671                 }
 672         } else if (strcmp(name, "DataDigest") == 0) {
 673                 if (conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY) {
 674                         log_debugx("discovery session; digests disabled");
 675                         keys_add(response_keys, name, "None");
 676                         return;
 677                 }
 678
 679                 which = login_list_prefers(value, "CRC32C", "None");
 680                 switch (which) {
 681                 case 1:
 682                         log_debugx("initiator prefers CRC32C "
 683                             "for data digest; we'll use it");
 684                         conn->conn_data_digest = CONN_DIGEST_CRC32C;
 685                         keys_add(response_keys, name, "CRC32C");
 686                         break;
 687                 case 2:
 688                         log_debugx("initiator prefers not to do "
 689                             "data digest; we'll comply");
 690                         keys_add(response_keys, name, "None");
 691                         break;
 692                 default:
 693                         log_warnx("initiator sent unrecognized "
 694                             "DataDigest value \"%s\"; will use None", value);
 695                         keys_add(response_keys, name, "None");
 696                         break;
 697                 }
 698         } else if (strcmp(name, "MaxConnections") == 0) {
 699                 keys_add(response_keys, name, "1");
 700         } else if (strcmp(name, "InitialR2T") == 0) {
 701                 keys_add(response_keys, name, "Yes");
 702         } else if (strcmp(name, "ImmediateData") == 0) {
 703                 if (conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY) {
 704                         log_debugx("discovery session; ImmediateData irrelevant");
 705                         keys_add(response_keys, name, "Irrelevant");
 706                 } else {
 707                         if (strcmp(value, "Yes") == 0) {
 708                                 conn->conn_immediate_data = true;
 709                                 keys_add(response_keys, name, "Yes");
 710                         } else {
 711                                 conn->conn_immediate_data = false;
 712                                 keys_add(response_keys, name, "No");
 713                         }
 714                 }
 715         } else if (strcmp(name, "MaxRecvDataSegmentLength") == 0) {
 716                 tmp = strtoul(value, NULL, 10);
 717                 if (tmp <= 0) {
 718                         login_send_error(request, 0x02, 0x00);
 719                         log_errx(1, "received invalid "
 720                             "MaxRecvDataSegmentLength");
 721                 }
 722                 if (tmp > MAX_DATA_SEGMENT_LENGTH) {
 723                         log_debugx("capping MaxRecvDataSegmentLength "
 724                             "from %d to %d", tmp, MAX_DATA_SEGMENT_LENGTH);
 725                         tmp = MAX_DATA_SEGMENT_LENGTH;
 726                 }
 727                 conn->conn_max_data_segment_length = tmp;
 728                 keys_add_int(response_keys, name, tmp);
 729         } else if (strcmp(name, "MaxBurstLength") == 0) {
 730                 tmp = strtoul(value, NULL, 10);
 731                 if (tmp <= 0) {
 732                         login_send_error(request, 0x02, 0x00);
 733                         log_errx(1, "received invalid MaxBurstLength");
 734                 }
 735                 if (tmp > MAX_BURST_LENGTH) {
 736                         log_debugx("capping MaxBurstLength from %d to %d",
 737                             tmp, MAX_BURST_LENGTH);
 738                         tmp = MAX_BURST_LENGTH;
 739                 }
 740                 conn->conn_max_burst_length = tmp;
 741                 keys_add(response_keys, name, value);
 742         } else if (strcmp(name, "FirstBurstLength") == 0) {
 743                 tmp = strtoul(value, NULL, 10);
 744                 if (tmp <= 0) {
 745                         login_send_error(request, 0x02, 0x00);
 746                         log_errx(1, "received invalid "
 747                             "FirstBurstLength");
 748                 }
 749                 if (tmp > MAX_DATA_SEGMENT_LENGTH) {
 750                         log_debugx("capping FirstBurstLength from %d to %d",
 751                             tmp, MAX_DATA_SEGMENT_LENGTH);
 752                         tmp = MAX_DATA_SEGMENT_LENGTH;
 753                 }
 754                 /*
 755                  * We don't pass the value to the kernel; it only enforces
 756                  * hardcoded limit anyway.
 757                  */
 758                 keys_add_int(response_keys, name, tmp);
 759         } else if (strcmp(name, "DefaultTime2Wait") == 0) {
 760                 keys_add(response_keys, name, value);
 761         } else if (strcmp(name, "DefaultTime2Retain") == 0) {
 762                 keys_add(response_keys, name, "0");
 763         } else if (strcmp(name, "MaxOutstandingR2T") == 0) {
 764                 keys_add(response_keys, name, "1");
 765         } else if (strcmp(name, "DataPDUInOrder") == 0) {
 766                 keys_add(response_keys, name, "Yes");
 767         } else if (strcmp(name, "DataSequenceInOrder") == 0) {
 768                 keys_add(response_keys, name, "Yes");
 769         } else if (strcmp(name, "ErrorRecoveryLevel") == 0) {
 770                 keys_add(response_keys, name, "0");
 771         } else if (strcmp(name, "OFMarker") == 0) {
 772                 keys_add(response_keys, name, "No");
 773         } else if (strcmp(name, "IFMarker") == 0) {
 774                 keys_add(response_keys, name, "No");
 775         } else {
 776                 log_debugx("unknown key \"%s\"; responding "
 777                     "with NotUnderstood", name);
 778                 keys_add(response_keys, name, "NotUnderstood");
 779         }
 780 }
 781
 782 static void
 783 login_negotiate(struct connection *conn, struct pdu *request)
 784 {
 785         struct pdu *response;
 786         struct iscsi_bhs_login_response *bhslr2;
 787         struct keys *request_keys, *response_keys;
 788         char *portal_group_tag;
 789         int i, rv;
 790         bool skipped_security;
 791
 792         if (request == NULL) {
 793                 log_debugx("beginning operational parameter negotiation; "
 794                     "waiting for Login PDU");
 795                 request = login_receive(conn, false);
 796                 skipped_security = false;
 797         } else
 798                 skipped_security = true;
 799
 800         request_keys = keys_new();
 801         keys_load(request_keys, request);
 802
 803         response = login_new_response(request);
 804         bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
 805         bhslr2->bhslr_flags |= BHSLR_FLAGS_TRANSIT;
 806         bhslr2->bhslr_tsih = htons(0xbadd);
 807         login_set_csg(response, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
 808         login_set_nsg(response, BHSLR_STAGE_FULL_FEATURE_PHASE);
 809         response_keys = keys_new();
 810
 811         if (skipped_security &&
 812             conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 813                 if (conn->conn_target->t_alias != NULL)
 814                         keys_add(response_keys,
 815                             "TargetAlias", conn->conn_target->t_alias);
 816                 rv = asprintf(&portal_group_tag, "%d",
 817                     conn->conn_portal->p_portal_group->pg_tag);
 818                 if (rv <= 0)
 819                         log_err(1, "asprintf");
 820                 keys_add(response_keys,
 821                     "TargetPortalGroupTag", portal_group_tag);
 822                 free(portal_group_tag);
 823         }
 824
 825         for (i = 0; i < KEYS_MAX; i++) {
 826                 if (request_keys->keys_names[i] == NULL)
 827                         break;
 828
 829                 login_negotiate_key(request, request_keys->keys_names[i],
 830                     request_keys->keys_values[i], skipped_security,
 831                     response_keys);
 832         }
 833
 834         log_debugx("operational parameter negotiation done; "
 835             "transitioning to Full Feature Phase");
 836
 837         keys_save(response_keys, response);
 838         pdu_send(response);
 839         pdu_delete(response);
 840         keys_delete(response_keys);
 841         pdu_delete(request);
 842         keys_delete(request_keys);
 843 }
 844
 845 void
 846 login(struct connection *conn)
 847 {
 848         struct pdu *request, *response;
 849         struct iscsi_bhs_login_request *bhslr;
 850         struct iscsi_bhs_login_response *bhslr2;
 851         struct keys *request_keys, *response_keys;
 852         struct auth_group *ag;
 853         const char *initiator_name, *initiator_alias, *session_type,
 854             *target_name, *auth_method;
 855         char *portal_group_tag;
 856         int rv;
 857
 858         /*
 859          * Handle the initial Login Request - figure out required authentication
 860          * method and either transition to the next phase, if no authentication
 861          * is required, or call appropriate authentication code.
 862          */
 863         log_debugx("beginning Login Phase; waiting for Login PDU");
 864         request = login_receive(conn, true);
 865         bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
 866         if (bhslr->bhslr_tsih != 0) {
 867                 login_send_error(request, 0x02, 0x0a);
 868                 log_errx(1, "received Login PDU with non-zero TSIH");
 869         }
 870
 871         memcpy(conn->conn_initiator_isid, bhslr->bhslr_isid,
 872             sizeof(conn->conn_initiator_isid));
 873
 874         /*
 875          * XXX: Implement the C flag some day.
 876          */
 877         request_keys = keys_new();
 878         keys_load(request_keys, request);
 879
 880         assert(conn->conn_initiator_name == NULL);
 881         initiator_name = keys_find(request_keys, "InitiatorName");
 882         if (initiator_name == NULL) {
 883                 login_send_error(request, 0x02, 0x07);
 884                 log_errx(1, "received Login PDU without InitiatorName");
 885         }
 886         if (valid_iscsi_name(initiator_name) == false) {
 887                 login_send_error(request, 0x02, 0x00);
 888                 log_errx(1, "received Login PDU with invalid InitiatorName");
 889         }
 890         conn->conn_initiator_name = checked_strdup(initiator_name);
 891         log_set_peer_name(conn->conn_initiator_name);
 892         /*
 893          * XXX: This doesn't work (does nothing) because of Capsicum.
 894          */
 895         setproctitle("%s (%s)", conn->conn_initiator_addr, conn->conn_initiator_name);
 896
 897         initiator_alias = keys_find(request_keys, "InitiatorAlias");
 898         if (initiator_alias != NULL)
 899                 conn->conn_initiator_alias = checked_strdup(initiator_alias);
 900
 901         assert(conn->conn_session_type == CONN_SESSION_TYPE_NONE);
 902         session_type = keys_find(request_keys, "SessionType");
 903         if (session_type != NULL) {
 904                 if (strcmp(session_type, "Normal") == 0) {
 905                         conn->conn_session_type = CONN_SESSION_TYPE_NORMAL;
 906                 } else if (strcmp(session_type, "Discovery") == 0) {
 907                         conn->conn_session_type = CONN_SESSION_TYPE_DISCOVERY;
 908                 } else {
 909                         login_send_error(request, 0x02, 0x00);
 910                         log_errx(1, "received Login PDU with invalid "
 911                             "SessionType \"%s\"", session_type);
 912                 }
 913         } else
 914                 conn->conn_session_type = CONN_SESSION_TYPE_NORMAL;
 915
 916         assert(conn->conn_target == NULL);
 917         if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 918                 target_name = keys_find(request_keys, "TargetName");
 919                 if (target_name == NULL) {
 920                         login_send_error(request, 0x02, 0x07);
 921                         log_errx(1, "received Login PDU without TargetName");
 922                 }
 923
 924                 conn->conn_target =
 925                     target_find(conn->conn_portal->p_portal_group->pg_conf,
 926                     target_name);
 927                 if (conn->conn_target == NULL) {
 928                         login_send_error(request, 0x02, 0x03);
 929                         log_errx(1, "requested target \"%s\" not found",
 930                             target_name);
 931                 }
 932         }
 933
 934         /*
 935          * At this point we know what kind of authentication we need.
 936          */
 937         if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
 938                 ag = conn->conn_target->t_auth_group;
 939                 if (ag->ag_name != NULL) {
 940                         log_debugx("initiator requests to connect "
 941                             "to target \"%s\"; auth-group \"%s\"",
 942                             conn->conn_target->t_name,
 943                             conn->conn_target->t_auth_group->ag_name);
 944                 } else {
 945                         log_debugx("initiator requests to connect "
 946                             "to target \"%s\"", conn->conn_target->t_name);
 947                 }
 948         } else {
 949                 assert(conn->conn_session_type == CONN_SESSION_TYPE_DISCOVERY);
 950                 ag = conn->conn_portal->p_portal_group->pg_discovery_auth_group;
 951                 if (ag->ag_name != NULL) {
 952                         log_debugx("initiator requests "
 953                             "discovery session; auth-group \"%s\"", ag->ag_name);
 954                 } else {
 955                         log_debugx("initiator requests discovery session");
 956                 }
 957         }
 958
 959         /*
 960          * Enforce initiator-name and initiator-portal.
 961          */
 962         if (auth_name_defined(ag)) {
 963                 if (auth_name_find(ag, initiator_name) == NULL) {
 964                         login_send_error(request, 0x02, 0x02);
 965                         log_errx(1, "initiator does not match allowed "
 966                             "initiator names");
 967                 }
 968                 log_debugx("initiator matches allowed initiator names");
 969         } else {
 970                 log_debugx("auth-group does not define initiator name "
 971                     "restrictions");
 972         }
 973
 974         if (auth_portal_defined(ag)) {
 975                 if (auth_portal_find(ag, &conn->conn_initiator_sa) == NULL) {
 976                         login_send_error(request, 0x02, 0x02);
 977                         log_errx(1, "initiator does not match allowed "
 978                             "initiator portals");
 979                 }
 980                 log_debugx("initiator matches allowed initiator portals");
 981         } else {
 982                 log_debugx("auth-group does not define initiator portal "
 983                     "restrictions");
 984         }
 985
 986         /*
 987          * Let's see if the initiator intends to do any kind of authentication
 988          * at all.
 989          */
 990         if (login_csg(request) == BHSLR_STAGE_OPERATIONAL_NEGOTIATION) {
 991                 if (ag->ag_type != AG_TYPE_NO_AUTHENTICATION) {
 992                         login_send_error(request, 0x02, 0x01);
 993                         log_errx(1, "initiator skipped the authentication, "
 994                             "but authentication is required");
 995                 }
 996
 997                 keys_delete(request_keys);
 998
 999                 log_debugx("initiator skipped the authentication, "
1000                     "and we don't need it; proceeding with negotiation");
1001                 login_negotiate(conn, request);
1002                 return;
1003         }
1004
1005         if (ag->ag_type == AG_TYPE_NO_AUTHENTICATION) {
1006                 /*
1007                  * Initiator might want to to authenticate,
1008                  * but we don't need it.
1009                  */
1010                 log_debugx("authentication not required; "
1011                     "transitioning to operational parameter negotiation");
1012
1013                 if ((bhslr->bhslr_flags & BHSLR_FLAGS_TRANSIT) == 0)
1014                         log_warnx("initiator did not set the \"T\" flag; "
1015                             "transitioning anyway");
1016
1017                 response = login_new_response(request);
1018                 bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
1019                 bhslr2->bhslr_flags |= BHSLR_FLAGS_TRANSIT;
1020                 login_set_nsg(response,
1021                     BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
1022                 response_keys = keys_new();
1023                 /*
1024                  * Required by Linux initiator.
1025                  */
1026                 auth_method = keys_find(request_keys, "AuthMethod");
1027                 if (auth_method != NULL &&
1028                     login_list_contains(auth_method, "None"))
1029                         keys_add(response_keys, "AuthMethod", "None");
1030
1031                 if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
1032                         if (conn->conn_target->t_alias != NULL)
1033                                 keys_add(response_keys,
1034                                     "TargetAlias", conn->conn_target->t_alias);
1035                         rv = asprintf(&portal_group_tag, "%d",
1036                             conn->conn_portal->p_portal_group->pg_tag);
1037                         if (rv <= 0)
1038                                 log_err(1, "asprintf");
1039                         keys_add(response_keys,
1040                             "TargetPortalGroupTag", portal_group_tag);
1041                         free(portal_group_tag);
1042                 }
1043                 keys_save(response_keys, response);
1044                 pdu_send(response);
1045                 pdu_delete(response);
1046                 keys_delete(response_keys);
1047                 pdu_delete(request);
1048                 keys_delete(request_keys);
1049
1050                 login_negotiate(conn, NULL);
1051                 return;
1052         }
1053
1054         if (ag->ag_type == AG_TYPE_DENY) {
1055                 login_send_error(request, 0x02, 0x01);
1056                 log_errx(1, "auth-type is \"deny\"");
1057         }
1058
1059         if (ag->ag_type == AG_TYPE_UNKNOWN) {
1060                 /*
1061                  * This can happen with empty auth-group.
1062                  */
1063                 login_send_error(request, 0x02, 0x01);
1064                 log_errx(1, "auth-type not set, denying access");
1065         }
1066
1067         log_debugx("CHAP authentication required");
1068
1069         auth_method = keys_find(request_keys, "AuthMethod");
1070         if (auth_method == NULL) {
1071                 login_send_error(request, 0x02, 0x07);
1072                 log_errx(1, "received Login PDU without AuthMethod");
1073         }
1074         /*
1075          * XXX: This should be Reject, not just a login failure (5.3.2).
1076          */
1077         if (login_list_contains(auth_method, "CHAP") == 0) {
1078                 login_send_error(request, 0x02, 0x01);
1079                 log_errx(1, "initiator requests unsupported AuthMethod \"%s\" "
1080                     "instead of \"CHAP\"", auth_method);
1081         }
1082
1083         response = login_new_response(request);
1084
1085         response_keys = keys_new();
1086         keys_add(response_keys, "AuthMethod", "CHAP");
1087         if (conn->conn_session_type == CONN_SESSION_TYPE_NORMAL) {
1088                 if (conn->conn_target->t_alias != NULL)
1089                         keys_add(response_keys,
1090                             "TargetAlias", conn->conn_target->t_alias);
1091                 rv = asprintf(&portal_group_tag, "%d",
1092                     conn->conn_portal->p_portal_group->pg_tag);
1093                 if (rv <= 0)
1094                         log_err(1, "asprintf");
1095                 keys_add(response_keys,
1096                     "TargetPortalGroupTag", portal_group_tag);
1097                 free(portal_group_tag);
1098         }
1099         keys_save(response_keys, response);
1100
1101         pdu_send(response);
1102         pdu_delete(response);
1103         keys_delete(response_keys);
1104         pdu_delete(request);
1105         keys_delete(request_keys);
1106
1107         login_chap(conn, ag);
1108
1109         login_negotiate(conn, NULL);
1110 }