=================================================================== RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/ssh/sshconnect.c,v retrieving revision 1.79.2.4 retrieving revision 1.79.2.5 diff -u -r1.79.2.4 -r1.79.2.5 --- src/usr.bin/ssh/sshconnect.c 2001/05/07 21:09:37 1.79.2.4 +++ src/usr.bin/ssh/sshconnect.c 2001/09/27 00:15:43 1.79.2.5 @@ -13,7 +13,7 @@ */ #include "includes.h" -RCSID("$OpenBSD: sshconnect.c,v 1.79.2.4 2001/05/07 21:09:37 jason Exp $"); +RCSID("$OpenBSD: sshconnect.c,v 1.79.2.5 2001/09/27 00:15:43 miod Exp $"); #include @@ -41,10 +41,31 @@ /* AF_UNSPEC or AF_INET or AF_INET6 */ extern int IPv4or6; +static const char * +sockaddr_ntop(struct sockaddr *sa) +{ + void *addr; + static char addrbuf[INET6_ADDRSTRLEN]; + + switch (sa->sa_family) { + case AF_INET: + addr = &((struct sockaddr_in *)sa)->sin_addr; + break; + case AF_INET6: + addr = &((struct sockaddr_in6 *)sa)->sin6_addr; + break; + default: + /* This case should be protected against elsewhere */ + abort(); + } + inet_ntop(sa->sa_family, addr, addrbuf, sizeof(addrbuf)); + return addrbuf; +} + /* * Connect to the given ssh server using a proxy command. */ -int +static int ssh_proxy_connect(const char *host, u_short port, struct passwd *pw, const char *proxy_command) { @@ -138,16 +159,18 @@ /* Set the connection file descriptors. */ packet_set_connection(pout[0], pin[1]); - return 1; + /* Indicate OK return */ + return 0; } /* * Creates a (possibly privileged) socket for use as the ssh connection. */ -int +static int ssh_create_socket(struct passwd *pw, int privileged, int family) { - int sock; + int sock, gaierr; + struct addrinfo hints, *res; /* * If we are running as root and want to connect to a privileged @@ -160,17 +183,40 @@ error("rresvport: af=%d %.100s", family, strerror(errno)); else debug("Allocated local port %d.", p); - } else { - /* - * Just create an ordinary socket on arbitrary port. We use - * the user's uid to create the socket. - */ - temporarily_use_uid(pw); - sock = socket(family, SOCK_STREAM, 0); - if (sock < 0) - error("socket: %.100s", strerror(errno)); - restore_uid(); + return sock; } + /* + * Just create an ordinary socket on arbitrary port. We use + * the user's uid to create the socket. + */ + temporarily_use_uid(pw); + sock = socket(family, SOCK_STREAM, 0); + if (sock < 0) + error("socket: %.100s", strerror(errno)); + restore_uid(); + + /* Bind the socket to an alternative local IP address */ + if (options.bind_address == NULL) + return sock; + + memset(&hints, 0, sizeof(hints)); + hints.ai_family = IPv4or6; + hints.ai_socktype = SOCK_STREAM; + hints.ai_flags = AI_PASSIVE; + gaierr = getaddrinfo(options.bind_address, "0", &hints, &res); + if (gaierr) { + error("getaddrinfo: %s: %s", options.bind_address, + gai_strerror(gaierr)); + close(sock); + return -1; + } + if (bind(sock, res->ai_addr, res->ai_addrlen) < 0) { + error("bind: %s: %s", options.bind_address, strerror(errno)); + close(sock); + freeaddrinfo(res); + return -1; + } + freeaddrinfo(res); return sock; } @@ -184,6 +230,12 @@ * second). If proxy_command is non-NULL, it specifies the command (with %h * and %p substituted for host and port, respectively) to use to contact * the daemon. + * Return values: + * 0 for OK + * ECONNREFUSED if we got a "Connection Refused" by the peer on any address + * ECONNABORTED if we failed without a "Connection refused" + * Suitable error messages for the connection failure will already have been + * printed. */ int ssh_connect(const char *host, struct sockaddr_storage * hostaddr, @@ -198,6 +250,12 @@ struct addrinfo hints, *ai, *aitop; struct linger linger; struct servent *sp; + /* + * Did we get only other errors than "Connection refused" (which + * should block fallback to rsh and similar), or did we get at least + * one "Connection refused"? + */ + int full_failure = 1; debug("ssh_connect: getuid %u geteuid %u anon %d", (u_int) getuid(), (u_int) geteuid(), anonymous); @@ -228,8 +286,8 @@ * Try to connect several times. On some machines, the first time * will sometimes fail. In general socket code appears to behave * quite magically on many machines. - */ - for (attempt = 0; attempt < connection_attempts; attempt++) { + */ + for (attempt = 0; ;) { if (attempt > 0) debug("Trying again..."); @@ -252,6 +310,7 @@ !anonymous && geteuid() == 0, ai->ai_family); if (sock < 0) + /* Any error is already output */ continue; /* Connect to the host. We use the user's uid in the @@ -265,7 +324,11 @@ restore_uid(); break; } else { - debug("connect: %.100s", strerror(errno)); + if (errno == ECONNREFUSED) + full_failure = 0; + log("ssh: connect to address %s port %s: %s", + sockaddr_ntop(ai->ai_addr), strport, + strerror(errno)); restore_uid(); /* * Close the failed socket; there appear to @@ -280,6 +343,9 @@ if (ai) break; /* Successful connection. */ + attempt++; + if (attempt >= connection_attempts) + break; /* Sleep a moment before retrying. */ sleep(1); } @@ -288,7 +354,7 @@ /* Return failure if we didn't get a successful connection. */ if (attempt >= connection_attempts) - return 0; + return full_failure ? ECONNABORTED : ECONNREFUSED; debug("Connection established."); @@ -310,14 +376,14 @@ /* Set the connection. */ packet_set_connection(sock, sock); - return 1; + return 0; } /* * Waits for the server identification string, and sends our own * identification string. */ -void +static void ssh_exchange_identification(void) { char buf[256], remote_version[256]; /* must be same size! */ @@ -402,8 +468,6 @@ fatal("Protocol major versions differ: %d vs. %d", (options.protocol & SSH_PROTO_2) ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1, remote_major); - if (compat20) - packet_set_ssh2_format(); /* Send our own protocol version identification. */ snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n", compat20 ? PROTOCOL_MAJOR_2 : PROTOCOL_MAJOR_1, @@ -418,7 +482,7 @@ } /* defaults to 'no' */ -int +static int read_yes_or_no(const char *prompt, int defval) { char buf[1024]; @@ -441,7 +505,10 @@ 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); } @@ -467,12 +534,13 @@ } /* - * 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 +static 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); @@ -496,10 +564,12 @@ /** 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; @@ -508,7 +578,7 @@ if (local && options.host_key_alias == NULL) { debug("Forcing accepting of host key for " "loopback/localhost."); - return; + return 0; } /* @@ -552,10 +622,12 @@ * 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 @@ -565,10 +637,12 @@ 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))) @@ -587,32 +661,49 @@ 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); @@ -620,13 +711,16 @@ } 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) { @@ -668,8 +762,11 @@ * 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 @@ -677,20 +774,26 @@ * 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. @@ -711,17 +814,41 @@ 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); +} + /* * Starts a dialog with the server, and authenticates the current user on the * server. This does not need any extra privileges. The basic connection @@ -769,7 +896,7 @@ char *padded; if (datafellows & SSH_BUG_PASSWORDPAD) { - packet_put_string(password, strlen(password)); + packet_put_cstring(password); return; } size = roundup(strlen(password) + 1, 32);