diff options
Diffstat (limited to 'sshconnect.c')
| -rw-r--r-- | sshconnect.c | 571 |
1 files changed, 420 insertions, 151 deletions
diff --git a/sshconnect.c b/sshconnect.c index af08be415..fcf87bb76 100644 --- a/sshconnect.c +++ b/sshconnect.c @@ -1,4 +1,4 @@ -/* $OpenBSD: sshconnect.c,v 1.329 2020/03/13 04:01:56 djm Exp $ */ +/* $OpenBSD: sshconnect.c,v 1.355 2021/07/02 05:11:21 dtucker Exp $ */ /* * Author: Tatu Ylonen <ylo@cs.hut.fi> * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland @@ -30,6 +30,7 @@ #include <ctype.h> #include <errno.h> #include <fcntl.h> +#include <limits.h> #include <netdb.h> #ifdef HAVE_PATHS_H #include <paths.h> @@ -89,11 +90,14 @@ expand_proxy_command(const char *proxy_command, const char *user, const char *host, const char *host_arg, int port) { char *tmp, *ret, strport[NI_MAXSERV]; + const char *keyalias = options.host_key_alias ? + options.host_key_alias : host_arg; snprintf(strport, sizeof strport, "%d", port); xasprintf(&tmp, "exec %s", proxy_command); ret = percent_expand(tmp, "h", host, + "k", keyalias, "n", host_arg, "p", strport, "r", options.user, @@ -102,24 +106,6 @@ expand_proxy_command(const char *proxy_command, const char *user, return ret; } -static void -stderr_null(void) -{ - int devnull; - - if ((devnull = open(_PATH_DEVNULL, O_WRONLY)) == -1) { - error("Can't open %s for stderr redirection: %s", - _PATH_DEVNULL, strerror(errno)); - return; - } - if (devnull == STDERR_FILENO) - return; - if (dup2(devnull, STDERR_FILENO) == -1) - error("Cannot redirect stderr to %s", _PATH_DEVNULL); - if (devnull > STDERR_FILENO) - close(devnull); -} - /* * Connect to the given ssh server using a proxy command that passes a * a connected fd back to us. @@ -166,8 +152,8 @@ ssh_proxy_fdpass_connect(struct ssh *ssh, const char *host, * error messages may be printed on the user's terminal. */ if (!debug_flag && options.control_path != NULL && - options.control_persist) - stderr_null(); + options.control_persist && stdfd_devnull(0, 0, 1) == -1) + error_f("stdfd_devnull failed"); argv[0] = shell; argv[1] = "-c"; @@ -249,16 +235,18 @@ ssh_proxy_connect(struct ssh *ssh, const char *host, const char *host_arg, * error messages may be printed on the user's terminal. */ if (!debug_flag && options.control_path != NULL && - options.control_persist) - stderr_null(); + options.control_persist && stdfd_devnull(0, 0, 1) == -1) + error_f("stdfd_devnull failed"); argv[0] = shell; argv[1] = "-c"; argv[2] = command_string; argv[3] = NULL; - /* Execute the proxy command. Note that we gave up any - extra privileges above. */ + /* + * Execute the proxy command. Note that we gave up any + * extra privileges above. + */ ssh_signal(SIGPIPE, SIG_DFL); execv(argv[0], argv); perror(argv[0]); @@ -329,8 +317,7 @@ check_ifaddrs(const char *ifname, int af, const struct ifaddrs *ifaddrs, htonl(INADDR_LOOPBACK)) continue; if (*rlenp < sizeof(struct sockaddr_in)) { - error("%s: v4 addr doesn't fit", - __func__); + error_f("v4 addr doesn't fit"); return -1; } *rlenp = sizeof(struct sockaddr_in); @@ -344,8 +331,7 @@ check_ifaddrs(const char *ifname, int af, const struct ifaddrs *ifaddrs, IN6_IS_ADDR_LOOPBACK(v6addr))) continue; if (*rlenp < sizeof(struct sockaddr_in6)) { - error("%s: v6 addr doesn't fit", - __func__); + error_f("v6 addr doesn't fit"); return -1; } *rlenp = sizeof(struct sockaddr_in6); @@ -380,6 +366,10 @@ ssh_create_socket(struct addrinfo *ai) } fcntl(sock, F_SETFD, FD_CLOEXEC); + /* Use interactive QOS (if specified) until authentication completed */ + if (options.ip_qos_interactive != INT_MAX) + set_sock_tos(sock, options.ip_qos_interactive); + /* Bind the socket to an alternative local IP address */ if (options.bind_address == NULL && options.bind_interface == NULL) return sock; @@ -406,14 +396,14 @@ ssh_create_socket(struct addrinfo *ai) #ifdef HAVE_IFADDRS_H if ((r = getifaddrs(&ifaddrs)) != 0) { error("getifaddrs: %s: %s", options.bind_interface, - strerror(errno)); + strerror(errno)); goto fail; } bindaddrlen = sizeof(bindaddr); if (check_ifaddrs(options.bind_interface, ai->ai_family, ifaddrs, &bindaddr, &bindaddrlen) != 0) { logit("getifaddrs: %s: no suitable addresses", - options.bind_interface); + options.bind_interface); goto fail; } #else @@ -422,15 +412,14 @@ ssh_create_socket(struct addrinfo *ai) } if ((r = getnameinfo((struct sockaddr *)&bindaddr, bindaddrlen, ntop, sizeof(ntop), NULL, 0, NI_NUMERICHOST)) != 0) { - error("%s: getnameinfo failed: %s", __func__, - ssh_gai_strerror(r)); + error_f("getnameinfo failed: %s", ssh_gai_strerror(r)); goto fail; } if (bind(sock, (struct sockaddr *)&bindaddr, bindaddrlen) != 0) { error("bind %s: %s", ntop, strerror(errno)); goto fail; } - debug("%s: bound to %s", __func__, ntop); + debug_f("bound to %s", ntop); /* success */ goto out; fail: @@ -457,15 +446,15 @@ fail: */ static int ssh_connect_direct(struct ssh *ssh, const char *host, struct addrinfo *aitop, - struct sockaddr_storage *hostaddr, u_short port, int family, - int connection_attempts, int *timeout_ms, int want_keepalive) + struct sockaddr_storage *hostaddr, u_short port, int connection_attempts, + int *timeout_ms, int want_keepalive) { int on = 1, saved_timeout_ms = *timeout_ms; int oerrno, sock = -1, attempt; char ntop[NI_MAXHOST], strport[NI_MAXSERV]; struct addrinfo *ai; - debug2("%s", __func__); + debug3_f("entering"); memset(ntop, 0, sizeof(ntop)); memset(strport, 0, sizeof(strport)); @@ -489,7 +478,7 @@ ssh_connect_direct(struct ssh *ssh, const char *host, struct addrinfo *aitop, ntop, sizeof(ntop), strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) { oerrno = errno; - error("%s: getnameinfo failed", __func__); + error_f("getnameinfo failed"); errno = oerrno; continue; } @@ -548,19 +537,19 @@ ssh_connect_direct(struct ssh *ssh, const char *host, struct addrinfo *aitop, int ssh_connect(struct ssh *ssh, const char *host, const char *host_arg, struct addrinfo *addrs, struct sockaddr_storage *hostaddr, u_short port, - int family, int connection_attempts, int *timeout_ms, int want_keepalive) + int connection_attempts, int *timeout_ms, int want_keepalive) { int in, out; if (options.proxy_command == NULL) { return ssh_connect_direct(ssh, host, addrs, hostaddr, port, - family, connection_attempts, timeout_ms, want_keepalive); + connection_attempts, timeout_ms, want_keepalive); } else if (strcmp(options.proxy_command, "-") == 0) { if ((in = dup(STDIN_FILENO)) == -1 || (out = dup(STDOUT_FILENO)) == -1) { if (in >= 0) close(in); - error("%s: dup() in/out failed", __func__); + error_f("dup() in/out failed"); return -1; /* ssh_packet_set_connection logs error */ } if ((ssh_packet_set_connection(ssh, in, out)) == NULL) @@ -594,7 +583,7 @@ confirm(const char *prompt, const char *fingerprint) if (p[0] == '\0' || strcasecmp(p, "no") == 0) ret = 0; else if (strcasecmp(p, "yes") == 0 || (fingerprint != NULL && - strcasecmp(p, fingerprint) == 0)) + strcmp(p, fingerprint) == 0)) ret = 1; free(cp); if (ret != -1) @@ -603,32 +592,6 @@ confirm(const char *prompt, const char *fingerprint) } static int -check_host_cert(const char *host, const struct sshkey *key) -{ - const char *reason; - int r; - - if (sshkey_cert_check_authority(key, 1, 0, host, &reason) != 0) { - error("%s", reason); - return 0; - } - if (sshbuf_len(key->cert->critical) != 0) { - error("Certificate for %s contains unsupported " - "critical options(s)", host); - return 0; - } - if ((r = sshkey_check_cert_sigtype(key, - options.ca_sign_algorithms)) != 0) { - logit("%s: certificate signature algorithm %s: %s", __func__, - (key->cert == NULL || key->cert->signature_type == NULL) ? - "(null)" : key->cert->signature_type, ssh_err(r)); - return 0; - } - - return 1; -} - -static int sockaddr_is_local(struct sockaddr *hostaddr) { switch (hostaddr->sa_family) { @@ -677,7 +640,7 @@ get_hostfile_hostname_ipaddr(char *hostname, struct sockaddr *hostaddr, if (options.proxy_command == NULL) { if (getnameinfo(hostaddr, addrlen, ntop, sizeof(ntop), NULL, 0, NI_NUMERICHOST) != 0) - fatal("%s: getnameinfo failed", __func__); + fatal_f("getnameinfo failed"); *hostfile_ipaddr = put_host_port(ntop, port); } else { *hostfile_ipaddr = xstrdup("<no hostip for proxy " @@ -701,6 +664,257 @@ get_hostfile_hostname_ipaddr(char *hostname, struct sockaddr *hostaddr, } } +/* returns non-zero if path appears in hostfiles, or 0 if not. */ +static int +path_in_hostfiles(const char *path, char **hostfiles, u_int num_hostfiles) +{ + u_int i; + + for (i = 0; i < num_hostfiles; i++) { + if (strcmp(path, hostfiles[i]) == 0) + return 1; + } + return 0; +} + +struct find_by_key_ctx { + const char *host, *ip; + const struct sshkey *key; + char **names; + u_int nnames; +}; + +/* Try to replace home directory prefix (per $HOME) with a ~/ sequence */ +static char * +try_tilde_unexpand(const char *path) +{ + char *home, *ret = NULL; + size_t l; + + if (*path != '/') + return xstrdup(path); + if ((home = getenv("HOME")) == NULL || (l = strlen(home)) == 0) + return xstrdup(path); + if (strncmp(path, home, l) != 0) + return xstrdup(path); + /* + * ensure we have matched on a path boundary: either the $HOME that + * we just compared ends with a '/' or the next character of the path + * must be a '/'. + */ + if (home[l - 1] != '/' && path[l] != '/') + return xstrdup(path); + if (path[l] == '/') + l++; + xasprintf(&ret, "~/%s", path + l); + return ret; +} + +static int +hostkeys_find_by_key_cb(struct hostkey_foreach_line *l, void *_ctx) +{ + struct find_by_key_ctx *ctx = (struct find_by_key_ctx *)_ctx; + char *path; + + /* we are looking for keys with names that *do not* match */ + if ((l->match & HKF_MATCH_HOST) != 0) + return 0; + /* not interested in marker lines */ + if (l->marker != MRK_NONE) + return 0; + /* we are only interested in exact key matches */ + if (l->key == NULL || !sshkey_equal(ctx->key, l->key)) + return 0; + path = try_tilde_unexpand(l->path); + debug_f("found matching key in %s:%lu", path, l->linenum); + ctx->names = xrecallocarray(ctx->names, + ctx->nnames, ctx->nnames + 1, sizeof(*ctx->names)); + xasprintf(&ctx->names[ctx->nnames], "%s:%lu: %s", path, l->linenum, + strncmp(l->hosts, HASH_MAGIC, strlen(HASH_MAGIC)) == 0 ? + "[hashed name]" : l->hosts); + ctx->nnames++; + free(path); + return 0; +} + +static int +hostkeys_find_by_key_hostfile(const char *file, const char *which, + struct find_by_key_ctx *ctx) +{ + int r; + + debug3_f("trying %s hostfile \"%s\"", which, file); + if ((r = hostkeys_foreach(file, hostkeys_find_by_key_cb, ctx, + ctx->host, ctx->ip, HKF_WANT_PARSE_KEY, 0)) != 0) { + if (r == SSH_ERR_SYSTEM_ERROR && errno == ENOENT) { + debug_f("hostkeys file %s does not exist", file); + return 0; + } + error_fr(r, "hostkeys_foreach failed for %s", file); + return r; + } + return 0; +} + +/* + * Find 'key' in known hosts file(s) that do not match host/ip. + * Used to display also-known-as information for previously-unseen hostkeys. + */ +static void +hostkeys_find_by_key(const char *host, const char *ip, const struct sshkey *key, + char **user_hostfiles, u_int num_user_hostfiles, + char **system_hostfiles, u_int num_system_hostfiles, + char ***names, u_int *nnames) +{ + struct find_by_key_ctx ctx = {0, 0, 0, 0, 0}; + u_int i; + + *names = NULL; + *nnames = 0; + + if (key == NULL || sshkey_is_cert(key)) + return; + + ctx.host = host; + ctx.ip = ip; + ctx.key = key; + + for (i = 0; i < num_user_hostfiles; i++) { + if (hostkeys_find_by_key_hostfile(user_hostfiles[i], + "user", &ctx) != 0) + goto fail; + } + for (i = 0; i < num_system_hostfiles; i++) { + if (hostkeys_find_by_key_hostfile(system_hostfiles[i], + "system", &ctx) != 0) + goto fail; + } + /* success */ + *names = ctx.names; + *nnames = ctx.nnames; + ctx.names = NULL; + ctx.nnames = 0; + return; + fail: + for (i = 0; i < ctx.nnames; i++) + free(ctx.names[i]); + free(ctx.names); +} + +#define MAX_OTHER_NAMES 8 /* Maximum number of names to list */ +static char * +other_hostkeys_message(const char *host, const char *ip, + const struct sshkey *key, + char **user_hostfiles, u_int num_user_hostfiles, + char **system_hostfiles, u_int num_system_hostfiles) +{ + char *ret = NULL, **othernames = NULL; + u_int i, n, num_othernames = 0; + + hostkeys_find_by_key(host, ip, key, + user_hostfiles, num_user_hostfiles, + system_hostfiles, num_system_hostfiles, + &othernames, &num_othernames); + if (num_othernames == 0) + return xstrdup("This key is not known by any other names"); + + xasprintf(&ret, "This host key is known by the following other " + "names/addresses:"); + + n = num_othernames; + if (n > MAX_OTHER_NAMES) + n = MAX_OTHER_NAMES; + for (i = 0; i < n; i++) { + xextendf(&ret, "\n", " %s", othernames[i]); + } + if (n < num_othernames) { + xextendf(&ret, "\n", " (%d additional names omitted)", + num_othernames - n); + } + for (i = 0; i < num_othernames; i++) + free(othernames[i]); + free(othernames); + return ret; +} + +void +load_hostkeys_command(struct hostkeys *hostkeys, const char *command_template, + const char *invocation, const struct ssh_conn_info *cinfo, + const struct sshkey *host_key, const char *hostfile_hostname) +{ + int r, i, ac = 0; + char *key_fp = NULL, *keytext = NULL, *tmp; + char *command = NULL, *tag = NULL, **av = NULL; + FILE *f = NULL; + pid_t pid; + void (*osigchld)(int); + + xasprintf(&tag, "KnownHostsCommand-%s", invocation); + + if (host_key != NULL) { + if ((key_fp = sshkey_fingerprint(host_key, + options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL) + fatal_f("sshkey_fingerprint failed"); + if ((r = sshkey_to_base64(host_key, &keytext)) != 0) + fatal_fr(r, "sshkey_to_base64 failed"); + } + /* + * NB. all returns later this function should go via "out" to + * ensure the original SIGCHLD handler is restored properly. + */ + osigchld = ssh_signal(SIGCHLD, SIG_DFL); + + /* Turn the command into an argument vector */ + if (argv_split(command_template, &ac, &av, 0) != 0) { + error("%s \"%s\" contains invalid quotes", tag, + command_template); + goto out; + } + if (ac == 0) { + error("%s \"%s\" yielded no arguments", tag, + command_template); + goto out; + } + for (i = 1; i < ac; i++) { + tmp = percent_dollar_expand(av[i], + DEFAULT_CLIENT_PERCENT_EXPAND_ARGS(cinfo), + "H", hostfile_hostname, + "I", invocation, + "t", host_key == NULL ? "NONE" : sshkey_ssh_name(host_key), + "f", key_fp == NULL ? "NONE" : key_fp, + "K", keytext == NULL ? "NONE" : keytext, + (char *)NULL); + if (tmp == NULL) + fatal_f("percent_expand failed"); + free(av[i]); + av[i] = tmp; + } + /* Prepare a printable command for logs, etc. */ + command = argv_assemble(ac, av); + + if ((pid = subprocess(tag, command, ac, av, &f, + SSH_SUBPROCESS_STDOUT_CAPTURE|SSH_SUBPROCESS_UNSAFE_PATH| + SSH_SUBPROCESS_PRESERVE_ENV, NULL, NULL, NULL)) == 0) + goto out; + + load_hostkeys_file(hostkeys, hostfile_hostname, tag, f, 1); + + if (exited_cleanly(pid, tag, command, 0) != 0) + fatal("KnownHostsCommand failed"); + + out: + if (f != NULL) + fclose(f); + ssh_signal(SIGCHLD, osigchld); + for (i = 0; i < ac; i++) + free(av[i]); + free(av); + free(tag); + free(command); + free(key_fp); + free(keytext); +} + /* * check whether the supplied host key is valid, return -1 if the key * is not valid. user_hostfile[0] will not be updated if 'readonly' is true. @@ -709,19 +923,20 @@ get_hostfile_hostname_ipaddr(char *hostname, struct sockaddr *hostaddr, #define RDONLY 1 #define ROQUIET 2 static int -check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port, - struct sshkey *host_key, int readonly, +check_host_key(char *hostname, const struct ssh_conn_info *cinfo, + struct sockaddr *hostaddr, u_short port, + struct sshkey *host_key, int readonly, int clobber_port, char **user_hostfiles, u_int num_user_hostfiles, - char **system_hostfiles, u_int num_system_hostfiles) + char **system_hostfiles, u_int num_system_hostfiles, + const char *hostfile_command) { - HostStatus host_status; - HostStatus ip_status; + HostStatus host_status = -1, ip_status = -1; struct sshkey *raw_key = NULL; char *ip = NULL, *host = NULL; char hostline[1000], *hostp, *fp, *ra; char msg[1024]; - const char *type; - const struct hostkey_entry *host_found, *ip_found; + const char *type, *fail_reason; + const struct hostkey_entry *host_found = NULL, *ip_found = NULL; int len, cancelled_forwarding = 0, confirmed; int local = sockaddr_is_local(hostaddr); int r, want_cert = sshkey_is_cert(host_key), host_ip_differ = 0; @@ -741,6 +956,7 @@ check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port, options.host_key_alias == NULL) { debug("Forcing accepting of host key for " "loopback/localhost."); + options.update_hostkeys = 0; return 0; } @@ -748,7 +964,8 @@ check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port, * Prepare the hostname and address strings used for hostkey lookup. * In some cases, these will have a port number appended. */ - get_hostfile_hostname_ipaddr(hostname, hostaddr, port, &host, &ip); + get_hostfile_hostname_ipaddr(hostname, hostaddr, + clobber_port ? 0 : port, &host, &ip); /* * Turn off check_host_ip if the connection is to localhost, via proxy @@ -760,17 +977,25 @@ check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port, host_hostkeys = init_hostkeys(); for (i = 0; i < num_user_hostfiles; i++) - load_hostkeys(host_hostkeys, host, user_hostfiles[i]); + load_hostkeys(host_hostkeys, host, user_hostfiles[i], 0); for (i = 0; i < num_system_hostfiles; i++) - load_hostkeys(host_hostkeys, host, system_hostfiles[i]); + load_hostkeys(host_hostkeys, host, system_hostfiles[i], 0); + if (hostfile_command != NULL && !clobber_port) { + load_hostkeys_command(host_hostkeys, hostfile_command, + "HOSTNAME", cinfo, host_key, host); + } ip_hostkeys = NULL; if (!want_cert && options.check_host_ip) { ip_hostkeys = init_hostkeys(); for (i = 0; i < num_user_hostfiles; i++) - load_hostkeys(ip_hostkeys, ip, user_hostfiles[i]); + load_hostkeys(ip_hostkeys, ip, user_hostfiles[i], 0); for (i = 0; i < num_system_hostfiles; i++) - load_hostkeys(ip_hostkeys, ip, system_hostfiles[i]); + load_hostkeys(ip_hostkeys, ip, system_hostfiles[i], 0); + if (hostfile_command != NULL && !clobber_port) { + load_hostkeys_command(ip_hostkeys, hostfile_command, + "ADDRESS", cinfo, host_key, ip); + } } retry: @@ -786,6 +1011,14 @@ check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port, &host_found); /* + * If there are no hostfiles, or if the hostkey was found via + * KnownHostsCommand, then don't try to touch the disk. + */ + if (!readonly && (num_user_hostfiles == 0 || + (host_found != NULL && host_found->note != 0))) + readonly = RDONLY; + + /* * Also perform check for the ip address, skip the check if we are * localhost, looking for a certificate, or the hostname was an ip * address to begin with. @@ -808,10 +1041,40 @@ check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port, host, type, want_cert ? "certificate" : "key"); debug("Found %s in %s:%lu", want_cert ? "CA key" : "key", host_found->file, host_found->line); - if (want_cert && - !check_host_cert(options.host_key_alias == NULL ? - hostname : options.host_key_alias, host_key)) - goto fail; + if (want_cert) { + if (sshkey_cert_check_host(host_key, + options.host_key_alias == NULL ? + hostname : options.host_key_alias, 0, + options.ca_sign_algorithms, &fail_reason) != 0) { + error("%s", fail_reason); + goto fail; + } + /* + * Do not attempt hostkey update if a certificate was + * successfully matched. + */ + if (options.update_hostkeys != 0) { + options.update_hostkeys = 0; + debug3_f("certificate host key in use; " + "disabling UpdateHostkeys"); + } + } + /* Turn off UpdateHostkeys if key was in system known_hosts */ + if (options.update_hostkeys != 0 && + (path_in_hostfiles(host_found->file, + system_hostfiles, num_system_hostfiles) || + (ip_status == HOST_OK && ip_found != NULL && + path_in_hostfiles(ip_found->file, + system_hostfiles, num_system_hostfiles)))) { + options.update_hostkeys = 0; + debug3_f("host key found in GlobalKnownHostsFile; " + "disabling UpdateHostkeys"); + } + if (options.update_hostkeys != 0 && host_found->note) { + options.update_hostkeys = 0; + debug3_f("host key found via KnownHostsCommand; " + "disabling UpdateHostkeys"); + } if (options.check_host_ip && ip_status == HOST_NEW) { if (readonly || want_cert) logit("%s host key for IP address " @@ -833,7 +1096,7 @@ check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port, ra = sshkey_fingerprint(host_key, options.fingerprint_hash, SSH_FP_RANDOMART); if (fp == NULL || ra == NULL) - fatal("%s: sshkey_fingerprint fail", __func__); + fatal_f("sshkey_fingerprint failed"); logit("Host key fingerprint is %s\n%s", fp, ra); free(ra); free(fp); @@ -842,11 +1105,13 @@ check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port, break; case HOST_NEW: if (options.host_key_alias == NULL && port != 0 && - port != SSH_DEFAULT_PORT) { + port != SSH_DEFAULT_PORT && !clobber_port) { debug("checking without port identifier"); - if (check_host_key(hostname, hostaddr, 0, host_key, - ROQUIET, user_hostfiles, num_user_hostfiles, - system_hostfiles, num_system_hostfiles) == 0) { + if (check_host_key(hostname, cinfo, hostaddr, 0, + host_key, ROQUIET, 1, + user_hostfiles, num_user_hostfiles, + system_hostfiles, num_system_hostfiles, + hostfile_command) == 0) { debug("found matching key w/out port"); break; } @@ -866,45 +1131,48 @@ check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port, goto fail; } else if (options.strict_host_key_checking == SSH_STRICT_HOSTKEY_ASK) { - char msg1[1024], msg2[1024]; + char *msg1 = NULL, *msg2 = NULL; + + xasprintf(&msg1, "The authenticity of host " + "'%.200s (%s)' can't be established", host, ip); + + if (show_other_keys(host_hostkeys, host_key)) { + xextendf(&msg1, "\n", "but keys of different " + "type are already known for this host."); + } else + xextendf(&msg1, "", "."); - if (show_other_keys(host_hostkeys, host_key)) - snprintf(msg1, sizeof(msg1), - "\nbut keys of different type are already" - " known for this host."); - else - snprintf(msg1, sizeof(msg1), "."); - /* The default */ fp = sshkey_fingerprint(host_key, options.fingerprint_hash, SSH_FP_DEFAULT); ra = sshkey_fingerprint(host_key, options.fingerprint_hash, SSH_FP_RANDOMART); if (fp == NULL || ra == NULL) - fatal("%s: sshkey_fingerprint fail", __func__); - msg2[0] = '\0'; + fatal_f("sshkey_fingerprint failed"); + xextendf(&msg1, "\n", "%s key fingerprint is %s.", + type, fp); + if (options.visual_host_key) + xextendf(&msg1, "\n", "%s", ra); if (options.verify_host_key_dns) { - if (matching_host_key_dns) - snprintf(msg2, sizeof(msg2), - "Matching host key fingerprint" - " found in DNS.\n"); - else - snprintf(msg2, sizeof(msg2), - "No matching host key fingerprint" - " found in DNS.\n"); + xextendf(&msg1, "\n", + "%s host key fingerprint found in DNS.", + matching_host_key_dns ? + "Matching" : "No matching"); } - snprintf(msg, sizeof(msg), - "The authenticity of host '%.200s (%s)' can't be " - "established%s\n" - "%s key fingerprint is %s.%s%s\n%s" + /* msg2 informs for other names matching this key */ + if ((msg2 = other_hostkeys_message(host, ip, host_key, + user_hostfiles, num_user_hostfiles, + system_hostfiles, num_system_hostfiles)) != NULL) + xextendf(&msg1, "\n", "%s", msg2); + + xextendf(&msg1, "\n", "Are you sure you want to continue connecting " - "(yes/no/[fingerprint])? ", - host, ip, msg1, type, fp, - options.visual_host_key ? "\n" : "", - options.visual_host_key ? ra : "", - msg2); + "(yes/no/[fingerprint])? "); + + confirmed = confirm(msg1, fp); free(ra); - confirmed = confirm(msg, fp); free(fp); + free(msg1); + free(msg2); if (!confirmed) goto fail; hostkey_trusted = 1; /* user explicitly confirmed */ @@ -1009,8 +1277,8 @@ check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port, */ if (options.strict_host_key_checking != SSH_STRICT_HOSTKEY_OFF) { - error("%s host key for %.200s has changed and you have " - "requested strict checking.", type, host); + error("Host key for %.200s has changed and you have " + "requested strict checking.", host); goto fail; } @@ -1030,13 +1298,6 @@ check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port, error("Keyboard-interactive authentication is disabled" " to avoid man-in-the-middle attacks."); options.kbd_interactive_authentication = 0; - options.challenge_response_authentication = 0; - cancelled_forwarding = 1; - } - if (options.challenge_response_authentication) { - error("Challenge/response authentication is disabled" - " to avoid man-in-the-middle attacks."); - options.challenge_response_authentication = 0; cancelled_forwarding = 1; } if (options.forward_agent) { @@ -1065,6 +1326,11 @@ check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port, options.tun_open = SSH_TUNMODE_NO; cancelled_forwarding = 1; } + if (options.update_hostkeys != 0) { + error("UpdateHostkeys is disabled because the host " + "key is not trusted."); + options.update_hostkeys = 0; + } if (options.exit_on_forward_failure && cancelled_forwarding) fatal("Error: forwarding disabled due to host key " "check failure"); @@ -1073,7 +1339,7 @@ check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port, * XXX Should permit the user to change to use the new id. * This could be done by converting the host key to an * identifying sentence, tell that the host identifies itself - * by that sentence, and ask the user if he/she wishes to + * by that sentence, and ask the user if they wish to * accept the authentication. */ break; @@ -1112,8 +1378,8 @@ check_host_key(char *hostname, struct sockaddr *hostaddr, u_short port, } if (!hostkey_trusted && options.update_hostkeys) { - debug("%s: hostkey not known or explicitly trusted: " - "disabling UpdateHostkeys", __func__); + debug_f("hostkey not known or explicitly trusted: " + "disabling UpdateHostkeys"); options.update_hostkeys = 0; } @@ -1133,10 +1399,9 @@ fail: */ debug("No matching CA found. Retry with plain key"); if ((r = sshkey_from_private(host_key, &raw_key)) != 0) - fatal("%s: sshkey_from_private: %s", - __func__, ssh_err(r)); + fatal_fr(r, "decode key"); if ((r = sshkey_drop_cert(raw_key)) != 0) - fatal("Couldn't drop certificate: %s", ssh_err(r)); + fatal_r(r, "Couldn't drop certificate"); host_key = raw_key; goto retry; } @@ -1152,7 +1417,8 @@ fail: /* returns 0 if key verifies or -1 if key does NOT verify */ int -verify_host_key(char *host, struct sockaddr *hostaddr, struct sshkey *host_key) +verify_host_key(char *host, struct sockaddr *hostaddr, struct sshkey *host_key, + const struct ssh_conn_info *cinfo) { u_int i; int r = -1, flags = 0; @@ -1161,7 +1427,7 @@ verify_host_key(char *host, struct sockaddr *hostaddr, struct sshkey *host_key) if ((fp = sshkey_fingerprint(host_key, options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL) { - error("%s: fingerprint host key: %s", __func__, ssh_err(r)); + error_fr(r, "fingerprint host key"); r = -1; goto out; } @@ -1169,8 +1435,7 @@ verify_host_key(char *host, struct sockaddr *hostaddr, struct sshkey *host_key) if (sshkey_is_cert(host_key)) { if ((cafp = sshkey_fingerprint(host_key->cert->signature_key, options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL) { - error("%s: fingerprint CA key: %s", - __func__, ssh_err(r)); + error_fr(r, "fingerprint CA key"); r = -1; goto out; } @@ -1192,8 +1457,8 @@ verify_host_key(char *host, struct sockaddr *hostaddr, struct sshkey *host_key) } if (sshkey_equal(previous_host_key, host_key)) { - debug2("%s: server host key %s %s matches cached key", - __func__, sshkey_type(host_key), fp); + debug2_f("server host key %s %s matches cached key", + sshkey_type(host_key), fp); r = 0; goto out; } @@ -1211,9 +1476,9 @@ verify_host_key(char *host, struct sockaddr *hostaddr, struct sshkey *host_key) r = -1; goto out; default: - error("Error checking host key %s %s in " - "revoked keys file %s: %s", sshkey_type(host_key), - fp, options.revoked_host_keys, ssh_err(r)); + error_r(r, "Error checking host key %s %s in " + "revoked keys file %s", sshkey_type(host_key), + fp, options.revoked_host_keys); r = -1; goto out; } @@ -1247,9 +1512,10 @@ verify_host_key(char *host, struct sockaddr *hostaddr, struct sshkey *host_key) } } } - r = check_host_key(host, hostaddr, options.port, host_key, RDRW, - options.user_hostfiles, options.num_user_hostfiles, - options.system_hostfiles, options.num_system_hostfiles); + r = check_host_key(host, cinfo, hostaddr, options.port, host_key, + RDRW, 0, options.user_hostfiles, options.num_user_hostfiles, + options.system_hostfiles, options.num_system_hostfiles, + options.known_hosts_command); out: sshkey_free(plain); @@ -1272,7 +1538,8 @@ out: */ void ssh_login(struct ssh *ssh, Sensitive *sensitive, const char *orighost, - struct sockaddr *hostaddr, u_short port, struct passwd *pw, int timeout_ms) + struct sockaddr *hostaddr, u_short port, struct passwd *pw, int timeout_ms, + const struct ssh_conn_info *cinfo) { char *host; char *server_user, *local_user; @@ -1295,7 +1562,7 @@ ssh_login(struct ssh *ssh, Sensitive *sensitive, const char *orighost, /* key exchange */ /* authenticate user */ debug("Authenticating to %s:%d as '%s'", host, port, server_user); - ssh_kex2(ssh, host, hostaddr, port); + ssh_kex2(ssh, host, hostaddr, port, cinfo); ssh_userauth2(ssh, local_user, server_user, host, sensitive); free(local_user); free(host); @@ -1320,14 +1587,15 @@ show_other_keys(struct hostkeys *hostkeys, struct sshkey *key) for (i = 0; type[i] != -1; i++) { if (type[i] == key->type) continue; - if (!lookup_key_in_hostkeys_by_type(hostkeys, type[i], &found)) + if (!lookup_key_in_hostkeys_by_type(hostkeys, type[i], + -1, &found)) continue; fp = sshkey_fingerprint(found->key, options.fingerprint_hash, SSH_FP_DEFAULT); ra = sshkey_fingerprint(found->key, options.fingerprint_hash, SSH_FP_RANDOMART); if (fp == NULL || ra == NULL) - fatal("%s: sshkey_fingerprint fail", __func__); + fatal_f("sshkey_fingerprint fail"); logit("WARNING: %s key found for host %s\n" "in %s:%lu\n" "%s key fingerprint %s.", @@ -1351,7 +1619,7 @@ warn_changed_key(struct sshkey *host_key) fp = sshkey_fingerprint(host_key, options.fingerprint_hash, SSH_FP_DEFAULT); if (fp == NULL) - fatal("%s: sshkey_fingerprint fail", __func__); + fatal_f("sshkey_fingerprint fail"); error("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"); error("@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @"); @@ -1430,7 +1698,8 @@ maybe_add_key_to_agent(const char *authfile, struct sshkey *private, if (sshkey_is_sk(private)) skprovider = options.sk_provider; if ((r = ssh_add_identity_constrained(auth_sock, private, - comment == NULL ? authfile : comment, 0, + comment == NULL ? authfile : comment, + options.add_keys_to_agent_lifespan, (options.add_keys_to_agent == 3), 0, skprovider)) == 0) debug("identity added to agent: %s", authfile); else |