=================================================================== RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/ssh/sshconnect.c,v retrieving revision 1.104.2.3 retrieving revision 1.105 diff -u -r1.104.2.3 -r1.105 --- src/usr.bin/ssh/sshconnect.c 2002/03/09 00:20:45 1.104.2.3 +++ src/usr.bin/ssh/sshconnect.c 2001/04/30 11:18:52 1.105 @@ -13,7 +13,7 @@ */ #include "includes.h" -RCSID("$OpenBSD: sshconnect.c,v 1.104.2.3 2002/03/09 00:20:45 miod Exp $"); +RCSID("$OpenBSD: sshconnect.c,v 1.105 2001/04/30 11:18:52 markus Exp $"); #include @@ -31,7 +31,6 @@ #include "readconf.h" #include "atomicio.h" #include "misc.h" -#include "readpass.h" char *client_version_string = NULL; char *server_version_string = NULL; @@ -39,31 +38,13 @@ extern Options options; extern char *__progname; -static const char * -sockaddr_ntop(struct sockaddr *sa) -{ - void *addr; - static char addrbuf[INET6_ADDRSTRLEN]; +/* AF_UNSPEC or AF_INET or AF_INET6 */ +extern int IPv4or6; - 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(); /* XXX abort is bad -- do something else */ - } - inet_ntop(sa->sa_family, addr, addrbuf, sizeof(addrbuf)); - return addrbuf; -} - /* * Connect to the given ssh server using a proxy command. */ -static int +int ssh_proxy_connect(const char *host, u_short port, struct passwd *pw, const char *proxy_command) { @@ -106,7 +87,7 @@ /* Create pipes for communicating with the proxy. */ if (pipe(pin) < 0 || pipe(pout) < 0) fatal("Could not create pipes to communicate with the proxy: %.100s", - strerror(errno)); + strerror(errno)); debug("Executing proxy command: %.500s", command_string); @@ -157,14 +138,13 @@ /* Set the connection file descriptors. */ packet_set_connection(pout[0], pin[1]); - /* Indicate OK return */ - return 0; + return 1; } /* * Creates a (possibly privileged) socket for use as the ssh connection. */ -static int +int ssh_create_socket(struct passwd *pw, int privileged, int family) { int sock, gaierr; @@ -198,7 +178,7 @@ return sock; memset(&hints, 0, sizeof(hints)); - hints.ai_family = family; + hints.ai_family = IPv4or6; hints.ai_socktype = SOCK_STREAM; hints.ai_flags = AI_PASSIVE; gaierr = getaddrinfo(options.bind_address, "0", &hints, &res); @@ -228,17 +208,12 @@ * 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, - u_short port, int family, int connection_attempts, - int anonymous, struct passwd *pw, const char *proxy_command) + u_short port, int connection_attempts, + int anonymous, struct passwd *pw, + const char *proxy_command) { int gaierr; int on = 1; @@ -247,15 +222,9 @@ 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); + (u_int) getuid(), (u_int) geteuid(), anonymous); /* Get default port if port has not been set. */ if (port == 0) { @@ -272,7 +241,7 @@ /* No proxy command. */ memset(&hints, 0, sizeof(hints)); - hints.ai_family = family; + hints.ai_family = IPv4or6; hints.ai_socktype = SOCK_STREAM; snprintf(strport, sizeof strport, "%d", port); if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) @@ -283,8 +252,8 @@ * 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; ;) { + */ + for (attempt = 0; attempt < connection_attempts; attempt++) { if (attempt > 0) debug("Trying again..."); @@ -307,7 +276,6 @@ !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 @@ -321,11 +289,7 @@ restore_uid(); break; } else { - if (errno == ECONNREFUSED) - full_failure = 0; - log("ssh: connect to address %s port %s: %s", - sockaddr_ntop(ai->ai_addr), strport, - strerror(errno)); + debug("connect: %.100s", strerror(errno)); restore_uid(); /* * Close the failed socket; there appear to @@ -333,15 +297,13 @@ * which connect() has already returned an * error. */ + shutdown(sock, SHUT_RDWR); close(sock); } } if (ai) break; /* Successful connection. */ - attempt++; - if (attempt >= connection_attempts) - break; /* Sleep a moment before retrying. */ sleep(1); } @@ -350,7 +312,7 @@ /* Return failure if we didn't get a successful connection. */ if (attempt >= connection_attempts) - return full_failure ? ECONNABORTED : ECONNREFUSED; + return 0; debug("Connection established."); @@ -372,14 +334,14 @@ /* Set the connection. */ packet_set_connection(sock, sock); - return 0; + return 1; } /* * Waits for the server identification string, and sends our own * identification string. */ -static void +void ssh_exchange_identification(void) { char buf[256], remote_version[256]; /* must be same size! */ @@ -421,12 +383,12 @@ &remote_major, &remote_minor, remote_version) != 3) fatal("Bad remote protocol version identification: '%.100s'", buf); debug("Remote protocol version %d.%d, remote software version %.100s", - remote_major, remote_minor, remote_version); + remote_major, remote_minor, remote_version); compat_datafellows(remote_version); mismatch = 0; - switch (remote_major) { + switch(remote_major) { case 1: if (remote_minor == 99 && (options.protocol & SSH_PROTO_2) && @@ -464,6 +426,8 @@ 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, @@ -478,38 +442,61 @@ } /* defaults to 'no' */ -static int -confirm(const char *prompt) +int +read_yes_or_no(const char *prompt, int defval) { - const char *msg, *again = "Please type 'yes' or 'no': "; - char *p; - int ret = -1; + char buf[1024]; + FILE *f; + int retval = -1; if (options.batch_mode) return 0; - for (msg = prompt;;msg = again) { - p = read_passphrase(msg, RP_ECHO); - if (p == NULL || - (p[0] == '\0') || (p[0] == '\n') || - strncasecmp(p, "no", 2) == 0) - ret = 0; - if (strncasecmp(p, "yes", 3) == 0) - ret = 1; - if (p) - xfree(p); - if (ret != -1) - return ret; + + if (isatty(STDIN_FILENO)) + f = stdin; + else + f = fopen(_PATH_TTY, "rw"); + + if (f == NULL) + return 0; + + fflush(stdout); + + while (1) { + fprintf(stderr, "%s", prompt); + if (fgets(buf, sizeof(buf), f) == NULL) { + /* Print a newline (the prompt probably didn\'t have one). */ + fprintf(stderr, "\n"); + strlcpy(buf, "no", sizeof buf); + } + /* Remove newline from response. */ + if (strchr(buf, '\n')) + *strchr(buf, '\n') = 0; + + if (buf[0] == 0) + retval = defval; + if (strcmp(buf, "yes") == 0) + retval = 1; + else if (strcmp(buf, "no") == 0) + retval = 0; + else + fprintf(stderr, "Please type 'yes' or 'no'.\n"); + + if (retval != -1) { + if (f != stdin) + fclose(f); + return retval; + } } } /* - * 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. + * check whether the supplied host key is valid, return only if ok. */ -static int +void check_host_key(char *host, struct sockaddr *hostaddr, Key *host_key, - int readonly, const char *user_hostfile, const char *system_hostfile) + const char *user_hostfile, const char *system_hostfile) { Key *file_key; char *type = key_type(host_key); @@ -519,8 +506,7 @@ HostStatus ip_status; int local = 0, host_ip_differ = 0; char ntop[NI_MAXHOST]; - char msg[1024]; - int len, host_line, ip_line; + int host_line, ip_line; const char *host_file = NULL, *ip_file = NULL; /* @@ -534,22 +520,19 @@ /** 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; break; } - if (options.no_host_authentication_for_localhost == 1 && local && - options.host_key_alias == NULL) { + if (local && options.host_key_alias == NULL) { debug("Forcing accepting of host key for " "loopback/localhost."); - return 0; + return; } /* @@ -593,12 +576,10 @@ * 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 @@ -608,12 +589,10 @@ 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))) @@ -632,46 +611,32 @@ host, type); debug("Found key in %s:%d", host_file, host_line); if (options.check_host_ip && ip_status == HOST_NEW) { - 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); + 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); + 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. - */ - error("No %s host key is known for %.200s and you " - "have requested strict checking.", type, host); - goto fail; + /* 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); } 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(msg, sizeof(msg), - "The authenticity of host '%.200s (%s)' can't be " - "established.\n" + snprintf(prompt, sizeof(prompt), + "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 (!confirm(msg)) - goto fail; + if (!read_yes_or_no(prompt, -1)) + fatal("Aborted by user!"); } if (options.check_host_ip && ip_status == HOST_NEW) { snprintf(hostline, sizeof(hostline), "%s,%s", host, ip); @@ -679,16 +644,13 @@ } 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) { @@ -730,11 +692,8 @@ * 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) { - error("%s host key for %.200s has changed and you have " - "requested strict checking.", type, host); - goto fail; - } + if (options.strict_host_key_checking) + fatal("%s host key for %.200s has changed and you have requested strict checking.", type, host); /* * If strict host key checking has not been requested, allow @@ -742,26 +701,20 @@ * agent forwarding. */ if (options.password_authentication) { - error("Password authentication is disabled to avoid " - "man-in-the-middle attacks."); + error("Password authentication is disabled to avoid trojan horses."); options.password_authentication = 0; } if (options.forward_agent) { - error("Agent forwarding is disabled to avoid " - "man-in-the-middle attacks."); + error("Agent forwarding is disabled to avoid trojan horses."); options.forward_agent = 0; } if (options.forward_x11) { - error("X11 forwarding is disabled to avoid " - "man-in-the-middle attacks."); + error("X11 forwarding is disabled to avoid trojan horses."); options.forward_x11 = 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; + 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; } /* * XXX Should permit the user to change to use the new id. @@ -775,55 +728,24 @@ if (options.check_host_ip && host_status != HOST_CHANGED && ip_status == HOST_CHANGED) { - snprintf(msg, sizeof(msg), - "Warning: the %s host key for '%.200s' " - "differs from the key for the IP address '%.128s'" - "\nOffending key for IP in %s:%d", - type, host, ip, ip_file, ip_line); - if (host_status == HOST_OK) { - len = strlen(msg); - snprintf(msg + len, sizeof(msg) - len, - "\nMatching host key in %s:%d", - host_file, host_line); - } + log("Warning: the %s host key for '%.200s' " + "differs from the key for the IP address '%.128s'", + type, host, ip); + if (host_status == HOST_OK) + 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) { - log(msg); - error("Exiting, you have requested strict checking."); - goto fail; + fatal("Exiting, you have requested strict checking."); } else if (options.strict_host_key_checking == 2) { - strlcat(msg, "\nAre you sure you want " - "to continue connecting (yes/no)? ", sizeof(msg)); - if (!confirm(msg)) - goto fail; - } else { - log(msg); + if (!read_yes_or_no("Are you sure you want " \ + "to continue connecting (yes/no)? ", -1)) + fatal("Aborted by user!"); } } 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 @@ -871,7 +793,7 @@ char *padded; if (datafellows & SSH_BUG_PASSWORDPAD) { - packet_put_cstring(password); + packet_put_string(password, strlen(password)); return; } size = roundup(strlen(password) + 1, 32);