diff options
Diffstat (limited to 'sshconnect.c')
-rw-r--r-- | sshconnect.c | 147 |
1 files changed, 105 insertions, 42 deletions
diff --git a/sshconnect.c b/sshconnect.c index bafdec95a..1766de0c3 100644 --- a/sshconnect.c +++ b/sshconnect.c | |||
@@ -13,7 +13,7 @@ | |||
13 | */ | 13 | */ |
14 | 14 | ||
15 | #include "includes.h" | 15 | #include "includes.h" |
16 | RCSID("$OpenBSD: sshconnect.c,v 1.107 2001/06/07 20:23:05 markus Exp $"); | 16 | RCSID("$OpenBSD: sshconnect.c,v 1.108 2001/06/23 02:34:31 markus Exp $"); |
17 | 17 | ||
18 | #include <openssl/bn.h> | 18 | #include <openssl/bn.h> |
19 | 19 | ||
@@ -467,7 +467,10 @@ read_yes_or_no(const char *prompt, int defval) | |||
467 | while (1) { | 467 | while (1) { |
468 | fprintf(stderr, "%s", prompt); | 468 | fprintf(stderr, "%s", prompt); |
469 | if (fgets(buf, sizeof(buf), f) == NULL) { | 469 | if (fgets(buf, sizeof(buf), f) == NULL) { |
470 | /* Print a newline (the prompt probably didn\'t have one). */ | 470 | /* |
471 | * Print a newline (the prompt probably didn\'t have | ||
472 | * one). | ||
473 | */ | ||
471 | fprintf(stderr, "\n"); | 474 | fprintf(stderr, "\n"); |
472 | strlcpy(buf, "no", sizeof buf); | 475 | strlcpy(buf, "no", sizeof buf); |
473 | } | 476 | } |
@@ -493,12 +496,13 @@ read_yes_or_no(const char *prompt, int defval) | |||
493 | } | 496 | } |
494 | 497 | ||
495 | /* | 498 | /* |
496 | * check whether the supplied host key is valid, return only if ok. | 499 | * check whether the supplied host key is valid, return -1 if the key |
500 | * is not valid. the user_hostfile will not be updated if 'readonly' is true. | ||
497 | */ | 501 | */ |
498 | 502 | ||
499 | void | 503 | int |
500 | check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key, | 504 | check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key, |
501 | const char *user_hostfile, const char *system_hostfile) | 505 | int readonly, const char *user_hostfile, const char *system_hostfile) |
502 | { | 506 | { |
503 | Key *file_key; | 507 | Key *file_key; |
504 | char *type = key_type(host_key); | 508 | char *type = key_type(host_key); |
@@ -523,11 +527,13 @@ check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key, | |||
523 | /** hostaddr == 0! */ | 527 | /** hostaddr == 0! */ |
524 | switch (hostaddr->sa_family) { | 528 | switch (hostaddr->sa_family) { |
525 | case AF_INET: | 529 | case AF_INET: |
526 | local = (ntohl(((struct sockaddr_in *)hostaddr)->sin_addr.s_addr) >> 24) == IN_LOOPBACKNET; | 530 | local = (ntohl(((struct sockaddr_in *)hostaddr)-> |
531 | sin_addr.s_addr) >> 24) == IN_LOOPBACKNET; | ||
527 | salen = sizeof(struct sockaddr_in); | 532 | salen = sizeof(struct sockaddr_in); |
528 | break; | 533 | break; |
529 | case AF_INET6: | 534 | case AF_INET6: |
530 | local = IN6_IS_ADDR_LOOPBACK(&(((struct sockaddr_in6 *)hostaddr)->sin6_addr)); | 535 | local = IN6_IS_ADDR_LOOPBACK( |
536 | &(((struct sockaddr_in6 *)hostaddr)->sin6_addr)); | ||
531 | salen = sizeof(struct sockaddr_in6); | 537 | salen = sizeof(struct sockaddr_in6); |
532 | break; | 538 | break; |
533 | default: | 539 | default: |
@@ -538,7 +544,7 @@ check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key, | |||
538 | if (local && options.host_key_alias == NULL) { | 544 | if (local && options.host_key_alias == NULL) { |
539 | debug("Forcing accepting of host key for " | 545 | debug("Forcing accepting of host key for " |
540 | "loopback/localhost."); | 546 | "loopback/localhost."); |
541 | return; | 547 | return 0; |
542 | } | 548 | } |
543 | 549 | ||
544 | /* | 550 | /* |
@@ -582,10 +588,12 @@ check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key, | |||
582 | * hosts or in the systemwide list. | 588 | * hosts or in the systemwide list. |
583 | */ | 589 | */ |
584 | host_file = user_hostfile; | 590 | host_file = user_hostfile; |
585 | host_status = check_host_in_hostfile(host_file, host, host_key, file_key, &host_line); | 591 | host_status = check_host_in_hostfile(host_file, host, host_key, |
592 | file_key, &host_line); | ||
586 | if (host_status == HOST_NEW) { | 593 | if (host_status == HOST_NEW) { |
587 | host_file = system_hostfile; | 594 | host_file = system_hostfile; |
588 | host_status = check_host_in_hostfile(host_file, host, host_key, file_key, &host_line); | 595 | host_status = check_host_in_hostfile(host_file, host, host_key, |
596 | file_key, &host_line); | ||
589 | } | 597 | } |
590 | /* | 598 | /* |
591 | * Also perform check for the ip address, skip the check if we are | 599 | * Also perform check for the ip address, skip the check if we are |
@@ -595,10 +603,12 @@ check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key, | |||
595 | Key *ip_key = key_new(host_key->type); | 603 | Key *ip_key = key_new(host_key->type); |
596 | 604 | ||
597 | ip_file = user_hostfile; | 605 | ip_file = user_hostfile; |
598 | ip_status = check_host_in_hostfile(ip_file, ip, host_key, ip_key, &ip_line); | 606 | ip_status = check_host_in_hostfile(ip_file, ip, host_key, |
607 | ip_key, &ip_line); | ||
599 | if (ip_status == HOST_NEW) { | 608 | if (ip_status == HOST_NEW) { |
600 | ip_file = system_hostfile; | 609 | ip_file = system_hostfile; |
601 | ip_status = check_host_in_hostfile(ip_file, ip, host_key, ip_key, &ip_line); | 610 | ip_status = check_host_in_hostfile(ip_file, ip, |
611 | host_key, ip_key, &ip_line); | ||
602 | } | 612 | } |
603 | if (host_status == HOST_CHANGED && | 613 | if (host_status == HOST_CHANGED && |
604 | (ip_status != HOST_CHANGED || !key_equal(ip_key, file_key))) | 614 | (ip_status != HOST_CHANGED || !key_equal(ip_key, file_key))) |
@@ -617,32 +627,49 @@ check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key, | |||
617 | host, type); | 627 | host, type); |
618 | debug("Found key in %s:%d", host_file, host_line); | 628 | debug("Found key in %s:%d", host_file, host_line); |
619 | if (options.check_host_ip && ip_status == HOST_NEW) { | 629 | if (options.check_host_ip && ip_status == HOST_NEW) { |
620 | if (!add_host_to_hostfile(user_hostfile, ip, host_key)) | 630 | if (readonly) |
621 | log("Failed to add the %s host key for IP address '%.128s' to the list of known hosts (%.30s).", | 631 | log("%s host key for IP address " |
622 | type, ip, user_hostfile); | 632 | "'%.128s' not in list of known hosts.", |
623 | else | ||
624 | log("Warning: Permanently added the %s host key for IP address '%.128s' to the list of known hosts.", | ||
625 | type, ip); | 633 | type, ip); |
634 | else if (!add_host_to_hostfile(user_hostfile, ip, | ||
635 | host_key)) | ||
636 | log("Failed to add the %s host key for IP " | ||
637 | "address '%.128s' to the list of known " | ||
638 | "hosts (%.30s).", type, ip, user_hostfile); | ||
639 | else | ||
640 | log("Warning: Permanently added the %s host " | ||
641 | "key for IP address '%.128s' to the list " | ||
642 | "of known hosts.", type, ip); | ||
626 | } | 643 | } |
627 | break; | 644 | break; |
628 | case HOST_NEW: | 645 | case HOST_NEW: |
646 | if (readonly) | ||
647 | goto fail; | ||
629 | /* The host is new. */ | 648 | /* The host is new. */ |
630 | if (options.strict_host_key_checking == 1) { | 649 | if (options.strict_host_key_checking == 1) { |
631 | /* User has requested strict host key checking. We will not add the host key | 650 | /* |
632 | automatically. The only alternative left is to abort. */ | 651 | * User has requested strict host key checking. We |
633 | fatal("No %s host key is known for %.200s and you have requested strict checking.", type, host); | 652 | * will not add the host key automatically. The only |
653 | * alternative left is to abort. | ||
654 | */ | ||
655 | error("No %s host key is known for %.200s and you " | ||
656 | "have requested strict checking.", type, host); | ||
657 | goto fail; | ||
634 | } else if (options.strict_host_key_checking == 2) { | 658 | } else if (options.strict_host_key_checking == 2) { |
635 | /* The default */ | 659 | /* The default */ |
636 | char prompt[1024]; | 660 | char prompt[1024]; |
637 | fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX); | 661 | fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX); |
638 | snprintf(prompt, sizeof(prompt), | 662 | snprintf(prompt, sizeof(prompt), |
639 | "The authenticity of host '%.200s (%s)' can't be established.\n" | 663 | "The authenticity of host '%.200s (%s)' can't be " |
664 | "established.\n" | ||
640 | "%s key fingerprint is %s.\n" | 665 | "%s key fingerprint is %s.\n" |
641 | "Are you sure you want to continue connecting (yes/no)? ", | 666 | "Are you sure you want to continue connecting " |
642 | host, ip, type, fp); | 667 | "(yes/no)? ", host, ip, type, fp); |
643 | xfree(fp); | 668 | xfree(fp); |
644 | if (!read_yes_or_no(prompt, -1)) | 669 | if (!read_yes_or_no(prompt, -1)) { |
645 | fatal("Aborted by user!"); | 670 | log("Aborted by user!"); |
671 | goto fail; | ||
672 | } | ||
646 | } | 673 | } |
647 | if (options.check_host_ip && ip_status == HOST_NEW) { | 674 | if (options.check_host_ip && ip_status == HOST_NEW) { |
648 | snprintf(hostline, sizeof(hostline), "%s,%s", host, ip); | 675 | snprintf(hostline, sizeof(hostline), "%s,%s", host, ip); |
@@ -650,13 +677,16 @@ check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key, | |||
650 | } else | 677 | } else |
651 | hostp = host; | 678 | hostp = host; |
652 | 679 | ||
653 | /* If not in strict mode, add the key automatically to the local known_hosts file. */ | 680 | /* |
681 | * If not in strict mode, add the key automatically to the | ||
682 | * local known_hosts file. | ||
683 | */ | ||
654 | if (!add_host_to_hostfile(user_hostfile, hostp, host_key)) | 684 | if (!add_host_to_hostfile(user_hostfile, hostp, host_key)) |
655 | log("Failed to add the host to the list of known hosts (%.500s).", | 685 | log("Failed to add the host to the list of known " |
656 | user_hostfile); | 686 | "hosts (%.500s).", user_hostfile); |
657 | else | 687 | else |
658 | log("Warning: Permanently added '%.200s' (%s) to the list of known hosts.", | 688 | log("Warning: Permanently added '%.200s' (%s) to the " |
659 | hostp, type); | 689 | "list of known hosts.", hostp, type); |
660 | break; | 690 | break; |
661 | case HOST_CHANGED: | 691 | case HOST_CHANGED: |
662 | if (options.check_host_ip && host_ip_differ) { | 692 | if (options.check_host_ip && host_ip_differ) { |
@@ -698,8 +728,11 @@ check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key, | |||
698 | * If strict host key checking is in use, the user will have | 728 | * If strict host key checking is in use, the user will have |
699 | * to edit the key manually and we can only abort. | 729 | * to edit the key manually and we can only abort. |
700 | */ | 730 | */ |
701 | if (options.strict_host_key_checking) | 731 | if (options.strict_host_key_checking) { |
702 | fatal("%s host key for %.200s has changed and you have requested strict checking.", type, host); | 732 | error("%s host key for %.200s has changed and you have " |
733 | "requested strict checking.", type, host); | ||
734 | goto fail; | ||
735 | } | ||
703 | 736 | ||
704 | /* | 737 | /* |
705 | * If strict host key checking has not been requested, allow | 738 | * If strict host key checking has not been requested, allow |
@@ -707,20 +740,26 @@ check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key, | |||
707 | * agent forwarding. | 740 | * agent forwarding. |
708 | */ | 741 | */ |
709 | if (options.password_authentication) { | 742 | if (options.password_authentication) { |
710 | error("Password authentication is disabled to avoid trojan horses."); | 743 | error("Password authentication is disabled to avoid " |
744 | "man-in-the-middle attacks."); | ||
711 | options.password_authentication = 0; | 745 | options.password_authentication = 0; |
712 | } | 746 | } |
713 | if (options.forward_agent) { | 747 | if (options.forward_agent) { |
714 | error("Agent forwarding is disabled to avoid trojan horses."); | 748 | error("Agent forwarding is disabled to avoid " |
749 | "man-in-the-middle attacks."); | ||
715 | options.forward_agent = 0; | 750 | options.forward_agent = 0; |
716 | } | 751 | } |
717 | if (options.forward_x11) { | 752 | if (options.forward_x11) { |
718 | error("X11 forwarding is disabled to avoid trojan horses."); | 753 | error("X11 forwarding is disabled to avoid " |
754 | "man-in-the-middle attacks."); | ||
719 | options.forward_x11 = 0; | 755 | options.forward_x11 = 0; |
720 | } | 756 | } |
721 | if (options.num_local_forwards > 0 || options.num_remote_forwards > 0) { | 757 | if (options.num_local_forwards > 0 || |
722 | error("Port forwarding is disabled to avoid trojan horses."); | 758 | options.num_remote_forwards > 0) { |
723 | options.num_local_forwards = options.num_remote_forwards = 0; | 759 | error("Port forwarding is disabled to avoid " |
760 | "man-in-the-middle attacks."); | ||
761 | options.num_local_forwards = | ||
762 | options.num_remote_forwards = 0; | ||
724 | } | 763 | } |
725 | /* | 764 | /* |
726 | * XXX Should permit the user to change to use the new id. | 765 | * XXX Should permit the user to change to use the new id. |
@@ -741,15 +780,39 @@ check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key, | |||
741 | log("Matching host key in %s:%d", host_file, host_line); | 780 | log("Matching host key in %s:%d", host_file, host_line); |
742 | log("Offending key for IP in %s:%d", ip_file, ip_line); | 781 | log("Offending key for IP in %s:%d", ip_file, ip_line); |
743 | if (options.strict_host_key_checking == 1) { | 782 | if (options.strict_host_key_checking == 1) { |
744 | fatal("Exiting, you have requested strict checking."); | 783 | error("Exiting, you have requested strict checking."); |
784 | goto fail; | ||
745 | } else if (options.strict_host_key_checking == 2) { | 785 | } else if (options.strict_host_key_checking == 2) { |
746 | if (!read_yes_or_no("Are you sure you want " \ | 786 | if (!read_yes_or_no("Are you sure you want " |
747 | "to continue connecting (yes/no)? ", -1)) | 787 | "to continue connecting (yes/no)? ", -1)) { |
748 | fatal("Aborted by user!"); | 788 | log("Aborted by user!"); |
789 | goto fail; | ||
790 | } | ||
749 | } | 791 | } |
750 | } | 792 | } |
751 | 793 | ||
752 | xfree(ip); | 794 | xfree(ip); |
795 | return 0; | ||
796 | |||
797 | fail: | ||
798 | xfree(ip); | ||
799 | return -1; | ||
800 | } | ||
801 | |||
802 | int | ||
803 | verify_host_key(char *host, struct sockaddr *hostaddr, Key *host_key) | ||
804 | { | ||
805 | struct stat st; | ||
806 | |||
807 | /* return ok if the key can be found in an old keyfile */ | ||
808 | if (stat(options.system_hostfile2, &st) == 0 || | ||
809 | stat(options.user_hostfile2, &st) == 0) { | ||
810 | if (check_host_key(host, hostaddr, host_key, /*readonly*/ 1, | ||
811 | options.user_hostfile2, options.system_hostfile2) == 0) | ||
812 | return 0; | ||
813 | } | ||
814 | return check_host_key(host, hostaddr, host_key, /*readonly*/ 0, | ||
815 | options.user_hostfile, options.system_hostfile); | ||
753 | } | 816 | } |
754 | 817 | ||
755 | /* | 818 | /* |