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-rw-r--r--usr.sbin/iscsid/login.c868
1 files changed, 868 insertions, 0 deletions
diff --git a/usr.sbin/iscsid/login.c b/usr.sbin/iscsid/login.c
new file mode 100644
index 0000000..2ea47cb
--- /dev/null
+++ b/usr.sbin/iscsid/login.c
@@ -0,0 +1,868 @@
+/*-
+ * Copyright (c) 2012 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * This software was developed by Edward Tomasz Napierala under sponsorship
+ * from the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#include <sys/types.h>
+#include <assert.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <netinet/in.h>
+#include <openssl/err.h>
+#include <openssl/md5.h>
+#include <openssl/rand.h>
+
+#include "iscsid.h"
+#include "iscsi_proto.h"
+
+static int
+login_nsg(const struct pdu *response)
+{
+ struct iscsi_bhs_login_response *bhslr;
+
+ bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
+
+ return (bhslr->bhslr_flags & 0x03);
+}
+
+static void
+login_set_nsg(struct pdu *request, int nsg)
+{
+ struct iscsi_bhs_login_request *bhslr;
+
+ assert(nsg == BHSLR_STAGE_SECURITY_NEGOTIATION ||
+ nsg == BHSLR_STAGE_OPERATIONAL_NEGOTIATION ||
+ nsg == BHSLR_STAGE_FULL_FEATURE_PHASE);
+
+ bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
+
+ bhslr->bhslr_flags &= 0xFC;
+ bhslr->bhslr_flags |= nsg;
+}
+
+static void
+login_set_csg(struct pdu *request, int csg)
+{
+ struct iscsi_bhs_login_request *bhslr;
+
+ assert(csg == BHSLR_STAGE_SECURITY_NEGOTIATION ||
+ csg == BHSLR_STAGE_OPERATIONAL_NEGOTIATION ||
+ csg == BHSLR_STAGE_FULL_FEATURE_PHASE);
+
+ bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
+
+ bhslr->bhslr_flags &= 0xF3;
+ bhslr->bhslr_flags |= csg << 2;
+}
+
+static const char *
+login_target_error_str(int class, int detail)
+{
+ static char msg[128];
+
+ /*
+ * RFC 3270, 10.13.5. Status-Class and Status-Detail
+ */
+ switch (class) {
+ case 0x01:
+ switch (detail) {
+ case 0x01:
+ return ("Target moved temporarily");
+ case 0x02:
+ return ("Target moved permanently");
+ default:
+ snprintf(msg, sizeof(msg), "unknown redirection; "
+ "Status-Class 0x%x, Status-Detail 0x%x",
+ class, detail);
+ return (msg);
+ }
+ case 0x02:
+ switch (detail) {
+ case 0x00:
+ return ("Initiator error");
+ case 0x01:
+ return ("Authentication failure");
+ case 0x02:
+ return ("Authorization failure");
+ case 0x03:
+ return ("Not found");
+ case 0x04:
+ return ("Target removed");
+ case 0x05:
+ return ("Unsupported version");
+ case 0x06:
+ return ("Too many connections");
+ case 0x07:
+ return ("Missing parameter");
+ case 0x08:
+ return ("Can't include in session");
+ case 0x09:
+ return ("Session type not supported");
+ case 0x0a:
+ return ("Session does not exist");
+ case 0x0b:
+ return ("Invalid during login");
+ default:
+ snprintf(msg, sizeof(msg), "unknown initiator error; "
+ "Status-Class 0x%x, Status-Detail 0x%x",
+ class, detail);
+ return (msg);
+ }
+ case 0x03:
+ switch (detail) {
+ case 0x00:
+ return ("Target error");
+ case 0x01:
+ return ("Service unavailable");
+ case 0x02:
+ return ("Out of resources");
+ default:
+ snprintf(msg, sizeof(msg), "unknown target error; "
+ "Status-Class 0x%x, Status-Detail 0x%x",
+ class, detail);
+ return (msg);
+ }
+ default:
+ snprintf(msg, sizeof(msg), "unknown error; "
+ "Status-Class 0x%x, Status-Detail 0x%x",
+ class, detail);
+ return (msg);
+ }
+}
+
+static struct pdu *
+login_receive(struct connection *conn, bool initial)
+{
+ struct pdu *response;
+ struct iscsi_bhs_login_response *bhslr;
+ const char *errorstr;
+
+ response = pdu_new(conn);
+ pdu_receive(response);
+ if (response->pdu_bhs->bhs_opcode != ISCSI_BHS_OPCODE_LOGIN_RESPONSE) {
+ log_errx(1, "protocol error: received invalid opcode 0x%x",
+ response->pdu_bhs->bhs_opcode);
+ }
+ bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
+ /*
+ * XXX: Implement the C flag some day.
+ */
+ if ((bhslr->bhslr_flags & BHSLR_FLAGS_CONTINUE) != 0)
+ log_errx(1, "received Login PDU with unsupported \"C\" flag");
+ if (bhslr->bhslr_version_max != 0x00)
+ log_errx(1, "received Login PDU with unsupported "
+ "Version-max 0x%x", bhslr->bhslr_version_max);
+ if (bhslr->bhslr_version_active != 0x00)
+ log_errx(1, "received Login PDU with unsupported "
+ "Version-active 0x%x", bhslr->bhslr_version_active);
+ if (bhslr->bhslr_status_class != 0) {
+ errorstr = login_target_error_str(bhslr->bhslr_status_class,
+ bhslr->bhslr_status_detail);
+ fail(conn, errorstr);
+ log_errx(1, "target returned error: %s", errorstr);
+ }
+#if 0
+ if (response->pdu_data_len == 0)
+ log_errx(1, "received Login PDU with empty data segment");
+#endif
+ if (initial == false &&
+ ntohl(bhslr->bhslr_statsn) != conn->conn_statsn + 1) {
+ /*
+ * It's a warning, not an error, to work around what seems
+ * to be bug in NetBSD iSCSI target.
+ */
+ log_warnx("received Login PDU with wrong StatSN: "
+ "is %d, should be %d", ntohl(bhslr->bhslr_statsn),
+ conn->conn_statsn + 1);
+ }
+ conn->conn_statsn = ntohl(bhslr->bhslr_statsn);
+
+ return (response);
+}
+
+static struct pdu *
+login_new_request(struct connection *conn)
+{
+ struct pdu *request;
+ struct iscsi_bhs_login_request *bhslr;
+
+ request = pdu_new(conn);
+ bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
+ bhslr->bhslr_opcode = ISCSI_BHS_OPCODE_LOGIN_REQUEST |
+ ISCSI_BHS_OPCODE_IMMEDIATE;
+ bhslr->bhslr_flags = BHSLR_FLAGS_TRANSIT;
+ login_set_csg(request, BHSLR_STAGE_SECURITY_NEGOTIATION);
+ login_set_nsg(request, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
+ memcpy(bhslr->bhslr_isid, &conn->conn_isid, sizeof(bhslr->bhslr_isid));
+ bhslr->bhslr_initiator_task_tag = 0;
+ bhslr->bhslr_cmdsn = 0;
+ bhslr->bhslr_expstatsn = htonl(conn->conn_statsn + 1);
+
+ return (request);
+}
+
+static int
+login_list_prefers(const char *list,
+ const char *choice1, const char *choice2)
+{
+ char *tofree, *str, *token;
+
+ tofree = str = checked_strdup(list);
+
+ while ((token = strsep(&str, ",")) != NULL) {
+ if (strcmp(token, choice1) == 0) {
+ free(tofree);
+ return (1);
+ }
+ if (strcmp(token, choice2) == 0) {
+ free(tofree);
+ return (2);
+ }
+ }
+ free(tofree);
+ return (-1);
+}
+
+static int
+login_hex2int(const char hex)
+{
+ switch (hex) {
+ case '0':
+ return (0x00);
+ case '1':
+ return (0x01);
+ case '2':
+ return (0x02);
+ case '3':
+ return (0x03);
+ case '4':
+ return (0x04);
+ case '5':
+ return (0x05);
+ case '6':
+ return (0x06);
+ case '7':
+ return (0x07);
+ case '8':
+ return (0x08);
+ case '9':
+ return (0x09);
+ case 'a':
+ case 'A':
+ return (0x0a);
+ case 'b':
+ case 'B':
+ return (0x0b);
+ case 'c':
+ case 'C':
+ return (0x0c);
+ case 'd':
+ case 'D':
+ return (0x0d);
+ case 'e':
+ case 'E':
+ return (0x0e);
+ case 'f':
+ case 'F':
+ return (0x0f);
+ default:
+ return (-1);
+ }
+}
+
+/*
+ * XXX: Review this _carefully_.
+ */
+static int
+login_hex2bin(const char *hex, char **binp, size_t *bin_lenp)
+{
+ int i, hex_len, nibble;
+ bool lo = true; /* As opposed to 'hi'. */
+ char *bin;
+ size_t bin_off, bin_len;
+
+ if (strncasecmp(hex, "0x", strlen("0x")) != 0) {
+ log_warnx("malformed variable, should start with \"0x\"");
+ return (-1);
+ }
+
+ hex += strlen("0x");
+ hex_len = strlen(hex);
+ if (hex_len < 1) {
+ log_warnx("malformed variable; doesn't contain anything "
+ "but \"0x\"");
+ return (-1);
+ }
+
+ bin_len = hex_len / 2 + hex_len % 2;
+ bin = calloc(bin_len, 1);
+ if (bin == NULL)
+ log_err(1, "calloc");
+
+ bin_off = bin_len - 1;
+ for (i = hex_len - 1; i >= 0; i--) {
+ nibble = login_hex2int(hex[i]);
+ if (nibble < 0) {
+ log_warnx("malformed variable, invalid char \"%c\"",
+ hex[i]);
+ return (-1);
+ }
+
+ assert(bin_off < bin_len);
+ if (lo) {
+ bin[bin_off] = nibble;
+ lo = false;
+ } else {
+ bin[bin_off] |= nibble << 4;
+ bin_off--;
+ lo = true;
+ }
+ }
+
+ *binp = bin;
+ *bin_lenp = bin_len;
+ return (0);
+}
+
+static char *
+login_bin2hex(const char *bin, size_t bin_len)
+{
+ unsigned char *hex, *tmp, ch;
+ size_t hex_len;
+ size_t i;
+
+ hex_len = bin_len * 2 + 3; /* +2 for "0x", +1 for '\0'. */
+ hex = malloc(hex_len);
+ if (hex == NULL)
+ log_err(1, "malloc");
+
+ tmp = hex;
+ tmp += sprintf(tmp, "0x");
+ for (i = 0; i < bin_len; i++) {
+ ch = bin[i];
+ tmp += sprintf(tmp, "%02x", ch);
+ }
+
+ return (hex);
+}
+
+static void
+login_compute_md5(const char id, const char *secret,
+ const void *challenge, size_t challenge_len, void *response,
+ size_t response_len)
+{
+ MD5_CTX ctx;
+ int rv;
+
+ assert(response_len == MD5_DIGEST_LENGTH);
+
+ MD5_Init(&ctx);
+ MD5_Update(&ctx, &id, sizeof(id));
+ MD5_Update(&ctx, secret, strlen(secret));
+ MD5_Update(&ctx, challenge, challenge_len);
+ rv = MD5_Final(response, &ctx);
+ if (rv != 1)
+ log_errx(1, "MD5_Final");
+}
+
+static void
+login_negotiate_key(struct connection *conn, const char *name,
+ const char *value)
+{
+ int which, tmp;
+
+ if (strcmp(name, "TargetAlias") == 0) {
+ strlcpy(conn->conn_target_alias, value,
+ sizeof(conn->conn_target_alias));
+ } else if (strcmp(value, "Irrelevant") == 0) {
+ /* Ignore. */
+ } else if (strcmp(name, "HeaderDigest") == 0) {
+ which = login_list_prefers(value, "CRC32C", "None");
+ switch (which) {
+ case 1:
+ log_debugx("target prefers CRC32C "
+ "for header digest; we'll use it");
+ conn->conn_header_digest = CONN_DIGEST_CRC32C;
+ break;
+ case 2:
+ log_debugx("target prefers not to do "
+ "header digest; we'll comply");
+ break;
+ default:
+ log_warnx("target sent unrecognized "
+ "HeaderDigest value \"%s\"; will use None", value);
+ break;
+ }
+ } else if (strcmp(name, "DataDigest") == 0) {
+ which = login_list_prefers(value, "CRC32C", "None");
+ switch (which) {
+ case 1:
+ log_debugx("target prefers CRC32C "
+ "for data digest; we'll use it");
+ conn->conn_data_digest = CONN_DIGEST_CRC32C;
+ break;
+ case 2:
+ log_debugx("target prefers not to do "
+ "data digest; we'll comply");
+ break;
+ default:
+ log_warnx("target sent unrecognized "
+ "DataDigest value \"%s\"; will use None", value);
+ break;
+ }
+ } else if (strcmp(name, "MaxConnections") == 0) {
+ /* Ignore. */
+ } else if (strcmp(name, "InitialR2T") == 0) {
+ if (strcmp(value, "Yes") == 0)
+ conn->conn_initial_r2t = true;
+ else
+ conn->conn_initial_r2t = false;
+ } else if (strcmp(name, "ImmediateData") == 0) {
+ if (strcmp(value, "Yes") == 0)
+ conn->conn_immediate_data = true;
+ else
+ conn->conn_immediate_data = false;
+ } else if (strcmp(name, "MaxRecvDataSegmentLength") == 0) {
+ tmp = strtoul(value, NULL, 10);
+ if (tmp <= 0)
+ log_errx(1, "received invalid "
+ "MaxRecvDataSegmentLength");
+ conn->conn_max_data_segment_length = tmp;
+ } else if (strcmp(name, "MaxBurstLength") == 0) {
+ if (conn->conn_immediate_data) {
+ tmp = strtoul(value, NULL, 10);
+ if (tmp <= 0)
+ log_errx(1, "received invalid MaxBurstLength");
+ conn->conn_max_burst_length = tmp;
+ }
+ } else if (strcmp(name, "FirstBurstLength") == 0) {
+ tmp = strtoul(value, NULL, 10);
+ if (tmp <= 0)
+ log_errx(1, "received invalid FirstBurstLength");
+ conn->conn_first_burst_length = tmp;
+ } else if (strcmp(name, "DefaultTime2Wait") == 0) {
+ /* Ignore */
+ } else if (strcmp(name, "DefaultTime2Retain") == 0) {
+ /* Ignore */
+ } else if (strcmp(name, "MaxOutstandingR2T") == 0) {
+ /* Ignore */
+ } else if (strcmp(name, "DataPDUInOrder") == 0) {
+ /* Ignore */
+ } else if (strcmp(name, "DataSequenceInOrder") == 0) {
+ /* Ignore */
+ } else if (strcmp(name, "ErrorRecoveryLevel") == 0) {
+ /* Ignore */
+ } else if (strcmp(name, "OFMarker") == 0) {
+ /* Ignore */
+ } else if (strcmp(name, "IFMarker") == 0) {
+ /* Ignore */
+ } else if (strcmp(name, "TargetPortalGroupTag") == 0) {
+ /* Ignore */
+ } else {
+ log_debugx("unknown key \"%s\"; ignoring", name);
+ }
+}
+
+static void
+login_negotiate(struct connection *conn)
+{
+ struct pdu *request, *response;
+ struct keys *request_keys, *response_keys;
+ struct iscsi_bhs_login_response *bhslr;
+ int i;
+
+ log_debugx("beginning parameter negotiation");
+ request = login_new_request(conn);
+ login_set_csg(request, BHSLR_STAGE_OPERATIONAL_NEGOTIATION);
+ login_set_nsg(request, BHSLR_STAGE_FULL_FEATURE_PHASE);
+ request_keys = keys_new();
+ if (conn->conn_conf.isc_discovery == 0) {
+ if (conn->conn_conf.isc_header_digest != 0)
+ keys_add(request_keys, "HeaderDigest", "CRC32C");
+ if (conn->conn_conf.isc_data_digest != 0)
+ keys_add(request_keys, "DataDigest", "CRC32C");
+
+ keys_add(request_keys, "ImmediateData", "Yes");
+ keys_add_int(request_keys, "MaxBurstLength",
+ ISCSI_MAX_DATA_SEGMENT_LENGTH);
+ keys_add_int(request_keys, "FirstBurstLength",
+ ISCSI_MAX_DATA_SEGMENT_LENGTH);
+ }
+ keys_add(request_keys, "InitialR2T", "Yes");
+ keys_add_int(request_keys, "MaxRecvDataSegmentLength",
+ ISCSI_MAX_DATA_SEGMENT_LENGTH);
+ keys_add(request_keys, "DefaultTime2Wait", "0");
+ keys_add(request_keys, "DefaultTime2Retain", "0");
+ keys_save(request_keys, request);
+ keys_delete(request_keys);
+ request_keys = NULL;
+ pdu_send(request);
+ pdu_delete(request);
+ request = NULL;
+
+ response = login_receive(conn, false);
+ response_keys = keys_new();
+ keys_load(response_keys, response);
+ for (i = 0; i < KEYS_MAX; i++) {
+ if (response_keys->keys_names[i] == NULL)
+ break;
+
+ login_negotiate_key(conn,
+ response_keys->keys_names[i], response_keys->keys_values[i]);
+ }
+
+ bhslr = (struct iscsi_bhs_login_response *)response->pdu_bhs;
+ if ((bhslr->bhslr_flags & BHSLR_FLAGS_TRANSIT) == 0)
+ log_warnx("received final login response "
+ "without the \"T\" flag");
+ else if (login_nsg(response) != BHSLR_STAGE_FULL_FEATURE_PHASE)
+ log_warnx("received final login response with wrong NSG 0x%x",
+ login_nsg(response));
+
+ log_debugx("parameter negotiation done; "
+ "transitioning to Full Feature phase");
+
+ keys_delete(response_keys);
+ pdu_delete(response);
+}
+
+static void
+login_send_chap_a(struct connection *conn)
+{
+ struct pdu *request;
+ struct keys *request_keys;
+
+ request = login_new_request(conn);
+ request_keys = keys_new();
+ keys_add(request_keys, "CHAP_A", "5");
+ keys_save(request_keys, request);
+ keys_delete(request_keys);
+ pdu_send(request);
+ pdu_delete(request);
+}
+
+static void
+login_send_chap_r(struct pdu *response)
+{
+ struct connection *conn;
+ struct pdu *request;
+ struct keys *request_keys, *response_keys;
+ const char *chap_a, *chap_c, *chap_i;
+ char *chap_r, *challenge, response_bin[MD5_DIGEST_LENGTH];
+ size_t challenge_len;
+ int error, rv;
+ unsigned char id;
+ char *mutual_chap_c, mutual_chap_i[4];
+
+ /*
+ * As in the rest of the initiator, 'request' means
+ * 'initiator -> target', and 'response' means 'target -> initiator',
+ *
+ * So, here the 'response' from the target is the packet that contains
+ * CHAP challenge; our CHAP response goes into 'request'.
+ */
+
+ conn = response->pdu_connection;
+
+ response_keys = keys_new();
+ keys_load(response_keys, response);
+
+ /*
+ * First, compute the response.
+ */
+ chap_a = keys_find(response_keys, "CHAP_A");
+ if (chap_a == NULL)
+ log_errx(1, "received CHAP packet without CHAP_A");
+ chap_c = keys_find(response_keys, "CHAP_C");
+ if (chap_c == NULL)
+ log_errx(1, "received CHAP packet without CHAP_C");
+ chap_i = keys_find(response_keys, "CHAP_I");
+ if (chap_i == NULL)
+ log_errx(1, "received CHAP packet without CHAP_I");
+
+ if (strcmp(chap_a, "5") != 0)
+ log_errx(1, "received CHAP packet "
+ "with unsupported CHAP_A \"%s\"", chap_a);
+ id = strtoul(chap_i, NULL, 10);
+ error = login_hex2bin(chap_c, &challenge, &challenge_len);
+ if (error != 0)
+ log_errx(1, "received CHAP packet with malformed CHAP_C");
+ login_compute_md5(id, conn->conn_conf.isc_secret,
+ challenge, challenge_len, response_bin, sizeof(response_bin));
+ free(challenge);
+ chap_r = login_bin2hex(response_bin, sizeof(response_bin));
+
+ keys_delete(response_keys);
+
+ request = login_new_request(conn);
+ request_keys = keys_new();
+ keys_add(request_keys, "CHAP_N", conn->conn_conf.isc_user);
+ keys_add(request_keys, "CHAP_R", chap_r);
+ free(chap_r);
+
+ /*
+ * If we want mutual authentication, we're expected to send
+ * our CHAP_I/CHAP_C now.
+ */
+ if (conn->conn_conf.isc_mutual_user[0] != '\0') {
+ log_debugx("requesting mutual authentication; "
+ "binary challenge size is %zd bytes",
+ sizeof(conn->conn_mutual_challenge));
+
+ rv = RAND_bytes(conn->conn_mutual_challenge,
+ sizeof(conn->conn_mutual_challenge));
+ if (rv != 1) {
+ log_errx(1, "RAND_bytes failed: %s",
+ ERR_error_string(ERR_get_error(), NULL));
+ }
+ rv = RAND_bytes(&conn->conn_mutual_id,
+ sizeof(conn->conn_mutual_id));
+ if (rv != 1) {
+ log_errx(1, "RAND_bytes failed: %s",
+ ERR_error_string(ERR_get_error(), NULL));
+ }
+ mutual_chap_c = login_bin2hex(conn->conn_mutual_challenge,
+ sizeof(conn->conn_mutual_challenge));
+ snprintf(mutual_chap_i, sizeof(mutual_chap_i),
+ "%d", conn->conn_mutual_id);
+ keys_add(request_keys, "CHAP_I", mutual_chap_i);
+ keys_add(request_keys, "CHAP_C", mutual_chap_c);
+ free(mutual_chap_c);
+ }
+
+ keys_save(request_keys, request);
+ keys_delete(request_keys);
+ pdu_send(request);
+ pdu_delete(request);
+}
+
+static void
+login_verify_mutual(const struct pdu *response)
+{
+ struct connection *conn;
+ struct keys *response_keys;
+ const char *chap_n, *chap_r;
+ char *response_bin, expected_response_bin[MD5_DIGEST_LENGTH];
+ size_t response_bin_len;
+ int error;
+
+ conn = response->pdu_connection;
+
+ response_keys = keys_new();
+ keys_load(response_keys, response);
+
+ chap_n = keys_find(response_keys, "CHAP_N");
+ if (chap_n == NULL)
+ log_errx(1, "received CHAP Response PDU without CHAP_N");
+ chap_r = keys_find(response_keys, "CHAP_R");
+ if (chap_r == NULL)
+ log_errx(1, "received CHAP Response PDU without CHAP_R");
+ error = login_hex2bin(chap_r, &response_bin, &response_bin_len);
+ if (error != 0)
+ log_errx(1, "received CHAP Response PDU with malformed CHAP_R");
+
+ if (strcmp(chap_n, conn->conn_conf.isc_mutual_user) != 0) {
+ fail(conn, "Mutual CHAP failed");
+ log_errx(1, "mutual CHAP authentication failed: wrong user");
+ }
+
+ login_compute_md5(conn->conn_mutual_id,
+ conn->conn_conf.isc_mutual_secret, conn->conn_mutual_challenge,
+ sizeof(conn->conn_mutual_challenge), expected_response_bin,
+ sizeof(expected_response_bin));
+
+ if (memcmp(response_bin, expected_response_bin,
+ sizeof(expected_response_bin)) != 0) {
+ fail(conn, "Mutual CHAP failed");
+ log_errx(1, "mutual CHAP authentication failed: wrong secret");
+ }
+
+ keys_delete(response_keys);
+ free(response_bin);
+
+ log_debugx("mutual CHAP authentication succeeded");
+}
+
+static void
+login_chap(struct connection *conn)
+{
+ struct pdu *response;
+
+ log_debugx("beginning CHAP authentication; sending CHAP_A");
+ login_send_chap_a(conn);
+
+ log_debugx("waiting for CHAP_A/CHAP_C/CHAP_I");
+ response = login_receive(conn, false);
+
+ log_debugx("sending CHAP_N/CHAP_R");
+ login_send_chap_r(response);
+ pdu_delete(response);
+
+ /*
+ * XXX: Make sure this is not susceptible to MITM.
+ */
+
+ log_debugx("waiting for CHAP result");
+ response = login_receive(conn, false);
+ if (conn->conn_conf.isc_mutual_user[0] != '\0')
+ login_verify_mutual(response);
+ pdu_delete(response);
+
+ log_debugx("CHAP authentication done");
+}
+
+static void
+login_create_isid(struct connection *conn)
+{
+ int rv;
+
+ /*
+ * RFC 3720, 10.12.5: 10b, "Random" ISID.
+ *
+ */
+ conn->conn_isid[0] = 0x80;
+
+ rv = RAND_bytes(&conn->conn_isid[1], 3);
+ if (rv != 1) {
+ log_errx(1, "RAND_bytes failed: %s",
+ ERR_error_string(ERR_get_error(), NULL));
+ }
+}
+
+void
+login(struct connection *conn)
+{
+ struct pdu *request, *response;
+ struct keys *request_keys, *response_keys;
+ struct iscsi_bhs_login_request *bhslr;
+ struct iscsi_bhs_login_response *bhslr2;
+ const char *auth_method;
+ int i;
+
+ login_create_isid(conn);
+
+ log_debugx("beginning Login phase; sending Login PDU");
+ request = login_new_request(conn);
+
+ bhslr = (struct iscsi_bhs_login_request *)request->pdu_bhs;
+ bhslr->bhslr_flags |= BHSLR_FLAGS_TRANSIT;
+
+ request_keys = keys_new();
+ if (conn->conn_conf.isc_user[0] == '\0')
+ keys_add(request_keys, "AuthMethod", "None");
+ else
+ keys_add(request_keys, "AuthMethod", "CHAP,None");
+ keys_add(request_keys, "InitiatorName",
+ conn->conn_conf.isc_initiator);
+ if (conn->conn_conf.isc_initiator_alias[0] != '\0') {
+ keys_add(request_keys, "InitiatorAlias",
+ conn->conn_conf.isc_initiator_alias);
+ }
+ if (conn->conn_conf.isc_discovery == 0) {
+ keys_add(request_keys, "SessionType", "Normal");
+ keys_add(request_keys,
+ "TargetName", conn->conn_conf.isc_target);
+ } else {
+ keys_add(request_keys, "SessionType", "Discovery");
+ }
+ keys_save(request_keys, request);
+ keys_delete(request_keys);
+ pdu_send(request);
+ pdu_delete(request);
+
+ response = login_receive(conn, true);
+
+ response_keys = keys_new();
+ keys_load(response_keys, response);
+
+ for (i = 0; i < KEYS_MAX; i++) {
+ if (response_keys->keys_names[i] == NULL)
+ break;
+
+ /*
+ * Not interested in AuthMethod at this point; we only need
+ * to parse things such as TargetAlias.
+ *
+ * XXX: This is somewhat ugly. We should have a way to apply
+ * all the keys to the session and use that by default
+ * instead of discarding them.
+ */
+ if (strcmp(response_keys->keys_names[i], "AuthMethod") == 0)
+ continue;
+
+ login_negotiate_key(conn,
+ response_keys->keys_names[i], response_keys->keys_values[i]);
+ }
+
+ bhslr2 = (struct iscsi_bhs_login_response *)response->pdu_bhs;
+ if ((bhslr2->bhslr_flags & BHSLR_FLAGS_TRANSIT) != 0 &&
+ login_nsg(response) == BHSLR_STAGE_OPERATIONAL_NEGOTIATION) {
+ log_debugx("target requested transition "
+ "to operational negotiation");
+
+ keys_delete(response_keys);
+ pdu_delete(response);
+ login_negotiate(conn);
+ return;
+ }
+
+ auth_method = keys_find(response_keys, "AuthMethod");
+ if (auth_method == NULL)
+ log_errx(1, "received response without AuthMethod");
+ if (strcmp(auth_method, "None") == 0) {
+ log_debugx("target does not require authentication");
+ keys_delete(response_keys);
+ pdu_delete(response);
+ login_negotiate(conn);
+ return;
+ }
+
+ if (strcmp(auth_method, "CHAP") != 0) {
+ fail(conn, "Unsupported AuthMethod");
+ log_errx(1, "received response "
+ "with unsupported AuthMethod \"%s\"", auth_method);
+ }
+
+ if (conn->conn_conf.isc_user[0] == '\0' ||
+ conn->conn_conf.isc_secret[0] == '\0') {
+ fail(conn, "Authentication required");
+ log_errx(1, "target requests CHAP authentication, but we don't "
+ "have user and secret");
+ }
+
+ keys_delete(response_keys);
+ response_keys = NULL;
+ pdu_delete(response);
+ response = NULL;
+
+ login_chap(conn);
+ login_negotiate(conn);
+}
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