=================================================================== RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/ssh/sshconnect.c,v retrieving revision 1.107 retrieving revision 1.108 diff -u -r1.107 -r1.108 --- src/usr.bin/ssh/sshconnect.c 2001/06/07 20:23:05 1.107 +++ src/usr.bin/ssh/sshconnect.c 2001/06/23 02:34:31 1.108 @@ -13,7 +13,7 @@ */ #include "includes.h" -RCSID("$OpenBSD: sshconnect.c,v 1.107 2001/06/07 20:23:05 markus Exp $"); +RCSID("$OpenBSD: sshconnect.c,v 1.108 2001/06/23 02:34:31 markus Exp $"); #include @@ -463,7 +463,10 @@ while (1) { fprintf(stderr, "%s", prompt); if (fgets(buf, sizeof(buf), f) == NULL) { - /* Print a newline (the prompt probably didn\'t have one). */ + /* + * Print a newline (the prompt probably didn\'t have + * one). + */ fprintf(stderr, "\n"); strlcpy(buf, "no", sizeof buf); } @@ -489,12 +492,13 @@ } /* - * check whether the supplied host key is valid, return only if ok. + * check whether the supplied host key is valid, return -1 if the key + * is not valid. the user_hostfile will not be updated if 'readonly' is true. */ -void +int check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key, - const char *user_hostfile, const char *system_hostfile) + int readonly, const char *user_hostfile, const char *system_hostfile) { Key *file_key; char *type = key_type(host_key); @@ -518,10 +522,12 @@ /** hostaddr == 0! */ switch (hostaddr->sa_family) { case AF_INET: - local = (ntohl(((struct sockaddr_in *)hostaddr)->sin_addr.s_addr) >> 24) == IN_LOOPBACKNET; + local = (ntohl(((struct sockaddr_in *)hostaddr)-> + sin_addr.s_addr) >> 24) == IN_LOOPBACKNET; break; case AF_INET6: - local = IN6_IS_ADDR_LOOPBACK(&(((struct sockaddr_in6 *)hostaddr)->sin6_addr)); + local = IN6_IS_ADDR_LOOPBACK( + &(((struct sockaddr_in6 *)hostaddr)->sin6_addr)); break; default: local = 0; @@ -530,7 +536,7 @@ if (local && options.host_key_alias == NULL) { debug("Forcing accepting of host key for " "loopback/localhost."); - return; + return 0; } /* @@ -574,10 +580,12 @@ * hosts or in the systemwide list. */ host_file = user_hostfile; - host_status = check_host_in_hostfile(host_file, host, host_key, file_key, &host_line); + host_status = check_host_in_hostfile(host_file, host, host_key, + file_key, &host_line); if (host_status == HOST_NEW) { host_file = system_hostfile; - host_status = check_host_in_hostfile(host_file, host, host_key, file_key, &host_line); + host_status = check_host_in_hostfile(host_file, host, host_key, + file_key, &host_line); } /* * Also perform check for the ip address, skip the check if we are @@ -587,10 +595,12 @@ Key *ip_key = key_new(host_key->type); ip_file = user_hostfile; - ip_status = check_host_in_hostfile(ip_file, ip, host_key, ip_key, &ip_line); + ip_status = check_host_in_hostfile(ip_file, ip, host_key, + ip_key, &ip_line); if (ip_status == HOST_NEW) { ip_file = system_hostfile; - ip_status = check_host_in_hostfile(ip_file, ip, host_key, ip_key, &ip_line); + ip_status = check_host_in_hostfile(ip_file, ip, + host_key, ip_key, &ip_line); } if (host_status == HOST_CHANGED && (ip_status != HOST_CHANGED || !key_equal(ip_key, file_key))) @@ -609,32 +619,49 @@ host, type); debug("Found key in %s:%d", host_file, host_line); if (options.check_host_ip && ip_status == HOST_NEW) { - if (!add_host_to_hostfile(user_hostfile, ip, host_key)) - log("Failed to add the %s host key for IP address '%.128s' to the list of known hosts (%.30s).", - type, ip, user_hostfile); - else - log("Warning: Permanently added the %s host key for IP address '%.128s' to the list of known hosts.", + if (readonly) + log("%s host key for IP address " + "'%.128s' not in list of known hosts.", type, ip); + else if (!add_host_to_hostfile(user_hostfile, ip, + host_key)) + log("Failed to add the %s host key for IP " + "address '%.128s' to the list of known " + "hosts (%.30s).", type, ip, user_hostfile); + else + log("Warning: Permanently added the %s host " + "key for IP address '%.128s' to the list " + "of known hosts.", type, ip); } break; case HOST_NEW: + if (readonly) + goto fail; /* The host is new. */ if (options.strict_host_key_checking == 1) { - /* User has requested strict host key checking. We will not add the host key - automatically. The only alternative left is to abort. */ - fatal("No %s host key is known for %.200s and you have requested strict checking.", type, host); + /* + * User has requested strict host key checking. We + * will not add the host key automatically. The only + * alternative left is to abort. + */ + error("No %s host key is known for %.200s and you " + "have requested strict checking.", type, host); + goto fail; } else if (options.strict_host_key_checking == 2) { /* The default */ char prompt[1024]; fp = key_fingerprint(host_key, SSH_FP_MD5, SSH_FP_HEX); snprintf(prompt, sizeof(prompt), - "The authenticity of host '%.200s (%s)' can't be established.\n" + "The authenticity of host '%.200s (%s)' can't be " + "established.\n" "%s key fingerprint is %s.\n" - "Are you sure you want to continue connecting (yes/no)? ", - host, ip, type, fp); + "Are you sure you want to continue connecting " + "(yes/no)? ", host, ip, type, fp); xfree(fp); - if (!read_yes_or_no(prompt, -1)) - fatal("Aborted by user!"); + if (!read_yes_or_no(prompt, -1)) { + log("Aborted by user!"); + goto fail; + } } if (options.check_host_ip && ip_status == HOST_NEW) { snprintf(hostline, sizeof(hostline), "%s,%s", host, ip); @@ -642,13 +669,16 @@ } else hostp = host; - /* If not in strict mode, add the key automatically to the local known_hosts file. */ + /* + * If not in strict mode, add the key automatically to the + * local known_hosts file. + */ if (!add_host_to_hostfile(user_hostfile, hostp, host_key)) - log("Failed to add the host to the list of known hosts (%.500s).", - user_hostfile); + log("Failed to add the host to the list of known " + "hosts (%.500s).", user_hostfile); else - log("Warning: Permanently added '%.200s' (%s) to the list of known hosts.", - hostp, type); + log("Warning: Permanently added '%.200s' (%s) to the " + "list of known hosts.", hostp, type); break; case HOST_CHANGED: if (options.check_host_ip && host_ip_differ) { @@ -690,8 +720,11 @@ * If strict host key checking is in use, the user will have * to edit the key manually and we can only abort. */ - if (options.strict_host_key_checking) - fatal("%s host key for %.200s has changed and you have requested strict checking.", type, host); + if (options.strict_host_key_checking) { + error("%s host key for %.200s has changed and you have " + "requested strict checking.", type, host); + goto fail; + } /* * If strict host key checking has not been requested, allow @@ -699,20 +732,26 @@ * agent forwarding. */ if (options.password_authentication) { - error("Password authentication is disabled to avoid trojan horses."); + error("Password authentication is disabled to avoid " + "man-in-the-middle attacks."); options.password_authentication = 0; } if (options.forward_agent) { - error("Agent forwarding is disabled to avoid trojan horses."); + error("Agent forwarding is disabled to avoid " + "man-in-the-middle attacks."); options.forward_agent = 0; } if (options.forward_x11) { - error("X11 forwarding is disabled to avoid trojan horses."); + error("X11 forwarding is disabled to avoid " + "man-in-the-middle attacks."); options.forward_x11 = 0; } - if (options.num_local_forwards > 0 || options.num_remote_forwards > 0) { - error("Port forwarding is disabled to avoid trojan horses."); - options.num_local_forwards = options.num_remote_forwards = 0; + if (options.num_local_forwards > 0 || + options.num_remote_forwards > 0) { + error("Port forwarding is disabled to avoid " + "man-in-the-middle attacks."); + options.num_local_forwards = + options.num_remote_forwards = 0; } /* * XXX Should permit the user to change to use the new id. @@ -733,15 +772,39 @@ log("Matching host key in %s:%d", host_file, host_line); log("Offending key for IP in %s:%d", ip_file, ip_line); if (options.strict_host_key_checking == 1) { - fatal("Exiting, you have requested strict checking."); + error("Exiting, you have requested strict checking."); + goto fail; } else if (options.strict_host_key_checking == 2) { - if (!read_yes_or_no("Are you sure you want " \ - "to continue connecting (yes/no)? ", -1)) - fatal("Aborted by user!"); + if (!read_yes_or_no("Are you sure you want " + "to continue connecting (yes/no)? ", -1)) { + log("Aborted by user!"); + goto fail; + } } } xfree(ip); + return 0; + +fail: + xfree(ip); + return -1; +} + +int +verify_host_key(char *host, struct sockaddr *hostaddr, Key *host_key) +{ + struct stat st; + + /* return ok if the key can be found in an old keyfile */ + if (stat(options.system_hostfile2, &st) == 0 || + stat(options.user_hostfile2, &st) == 0) { + if (check_host_key(host, hostaddr, host_key, /*readonly*/ 1, + options.user_hostfile2, options.system_hostfile2) == 0) + return 0; + } + return check_host_key(host, hostaddr, host_key, /*readonly*/ 0, + options.user_hostfile, options.system_hostfile); } /*