diff options
Diffstat (limited to 'sshd.c')
| -rw-r--r-- | sshd.c | 1816 |
1 files changed, 794 insertions, 1022 deletions
@@ -1,4 +1,4 @@ -/* $OpenBSD: sshd.c,v 1.444 2015/02/20 22:17:21 djm Exp $ */ +/* $OpenBSD: sshd.c,v 1.552 2020/03/13 04:01:57 djm Exp $ */ /* * Author: Tatu Ylonen <ylo@cs.hut.fi> * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland @@ -87,20 +87,19 @@ #include "xmalloc.h" #include "ssh.h" -#include "ssh1.h" #include "ssh2.h" -#include "rsa.h" #include "sshpty.h" #include "packet.h" #include "log.h" -#include "buffer.h" +#include "sshbuf.h" #include "misc.h" +#include "match.h" #include "servconf.h" #include "uidswap.h" #include "compat.h" #include "cipher.h" #include "digest.h" -#include "key.h" +#include "sshkey.h" #include "kex.h" #include "myproposal.h" #include "authfile.h" @@ -114,20 +113,16 @@ #include "dispatch.h" #include "channels.h" #include "session.h" -#include "monitor_mm.h" #include "monitor.h" #ifdef GSSAPI #include "ssh-gss.h" #endif #include "monitor_wrap.h" -#include "roaming.h" #include "ssh-sandbox.h" +#include "auth-options.h" #include "version.h" #include "ssherr.h" - -#ifndef O_NOCTTY -#define O_NOCTTY 0 -#endif +#include "sk-api.h" /* Re-exec fds */ #define REEXEC_DEVCRYPTO_RESERVED_FD (STDERR_FILENO + 1) @@ -151,46 +146,44 @@ char *config_file_name = _PATH_SERVER_CONFIG_FILE; */ int debug_flag = 0; -/* Flag indicating that the daemon should only test the configuration and keys. */ -int test_flag = 0; +/* + * Indicating that the daemon should only test the configuration and keys. + * If test_flag > 1 ("-T" flag), then sshd will also dump the effective + * configuration, optionally using connection information provided by the + * "-C" flag. + */ +static int test_flag = 0; /* Flag indicating that the daemon is being started from inetd. */ -int inetd_flag = 0; +static int inetd_flag = 0; /* Flag indicating that sshd should not detach and become a daemon. */ -int no_daemon_flag = 0; +static int no_daemon_flag = 0; /* debug goes to stderr unless inetd_flag is set */ -int log_stderr = 0; +static int log_stderr = 0; /* Saved arguments to main(). */ -char **saved_argv; -int saved_argc; +static char **saved_argv; +static int saved_argc; /* re-exec */ -int rexeced_flag = 0; -int rexec_flag = 1; -int rexec_argc = 0; -char **rexec_argv; +static int rexeced_flag = 0; +static int rexec_flag = 1; +static int rexec_argc = 0; +static char **rexec_argv; /* * The sockets that the server is listening; this is used in the SIGHUP * signal handler. */ #define MAX_LISTEN_SOCKS 16 -int listen_socks[MAX_LISTEN_SOCKS]; -int num_listen_socks = 0; - -/* - * the client's version string, passed by sshd2 in compat mode. if != NULL, - * sshd will skip the version-number exchange - */ -char *client_version_string = NULL; -char *server_version_string = NULL; +static int listen_socks[MAX_LISTEN_SOCKS]; +static int num_listen_socks = 0; /* Daemon's agent connection */ int auth_sock = -1; -int have_agent = 0; +static int have_agent = 0; /* * Any really sensitive data in the application is contained in this @@ -201,22 +194,12 @@ int have_agent = 0; * not very useful. Currently, memory locking is not implemented. */ struct { - Key *server_key; /* ephemeral server key */ - Key *ssh1_host_key; /* ssh1 host key */ - Key **host_keys; /* all private host keys */ - Key **host_pubkeys; /* all public host keys */ - Key **host_certificates; /* all public host certificates */ - int have_ssh1_key; - int have_ssh2_key; - u_char ssh1_cookie[SSH_SESSION_KEY_LENGTH]; + struct sshkey **host_keys; /* all private host keys */ + struct sshkey **host_pubkeys; /* all public host keys */ + struct sshkey **host_certificates; /* all public host certificates */ + int have_ssh2_key; } sensitive_data; -/* - * Flag indicating whether the RSA server key needs to be regenerated. - * Is set in the SIGALRM handler and cleared when the key is regenerated. - */ -static volatile sig_atomic_t key_do_regen = 0; - /* This is set to true when a signal is received. */ static volatile sig_atomic_t received_sighup = 0; static volatile sig_atomic_t received_sigterm = 0; @@ -231,23 +214,48 @@ u_int session_id2_len = 0; /* record remote hostname or ip */ u_int utmp_len = HOST_NAME_MAX+1; -/* options.max_startup sized array of fd ints */ -int *startup_pipes = NULL; -int startup_pipe; /* in child */ +/* + * startup_pipes/flags are used for tracking children of the listening sshd + * process early in their lifespans. This tracking is needed for three things: + * + * 1) Implementing the MaxStartups limit of concurrent unauthenticated + * connections. + * 2) Avoiding a race condition for SIGHUP processing, where child processes + * may have listen_socks open that could collide with main listener process + * after it restarts. + * 3) Ensuring that rexec'd sshd processes have received their initial state + * from the parent listen process before handling SIGHUP. + * + * Child processes signal that they have completed closure of the listen_socks + * and (if applicable) received their rexec state by sending a char over their + * sock. Child processes signal that authentication has completed by closing + * the sock (or by exiting). + */ +static int *startup_pipes = NULL; +static int *startup_flags = NULL; /* Indicates child closed listener */ +static int startup_pipe = -1; /* in child */ /* variables used for privilege separation */ int use_privsep = -1; struct monitor *pmonitor = NULL; int privsep_is_preauth = 1; +static int privsep_chroot = 1; -/* global authentication context */ +/* global connection state and authentication contexts */ Authctxt *the_authctxt = NULL; +struct ssh *the_active_state; + +/* global key/cert auth options. XXX move to permanent ssh->authctxt? */ +struct sshauthopt *auth_opts = NULL; /* sshd_config buffer */ -Buffer cfg; +struct sshbuf *cfg; + +/* Included files from the configuration file */ +struct include_list includes = TAILQ_HEAD_INITIALIZER(includes); /* message to be displayed after login */ -Buffer loginmsg; +struct sshbuf *loginmsg; /* Unprivileged user */ struct passwd *privsep_pw = NULL; @@ -255,11 +263,9 @@ struct passwd *privsep_pw = NULL; /* Prototypes for various functions defined later in this file. */ void destroy_sensitive_data(void); void demote_sensitive_data(void); +static void do_ssh2_kex(struct ssh *); -#ifdef WITH_SSH1 -static void do_ssh1_kex(void); -#endif -static void do_ssh2_kex(void); +static char *listener_proctitle; /* * Close all listening sockets @@ -295,11 +301,7 @@ close_startup_pipes(void) static void sighup_handler(int sig) { - int save_errno = errno; - received_sighup = 1; - signal(SIGHUP, sighup_handler); - errno = save_errno; } /* @@ -310,11 +312,12 @@ static void sighup_restart(void) { logit("Received SIGHUP; restarting."); + if (options.pid_file != NULL) + unlink(options.pid_file); platform_pre_restart(); close_listen_socks(); close_startup_pipes(); - alarm(0); /* alarm timer persists across exec */ - signal(SIGHUP, SIG_IGN); /* will be restored after exec */ + ssh_signal(SIGHUP, SIG_IGN); /* will be restored after exec */ execv(saved_argv[0], saved_argv); logit("RESTART FAILED: av[0]='%.100s', error: %.100s.", saved_argv[0], strerror(errno)); @@ -343,11 +346,11 @@ main_sigchld_handler(int sig) pid_t pid; int status; + debug("main_sigchld_handler: %s", strsignal(sig)); + while ((pid = waitpid(-1, &status, WNOHANG)) > 0 || - (pid < 0 && errno == EINTR)) + (pid == -1 && errno == EINTR)) ; - - signal(SIGCHLD, main_sigchld_handler); errno = save_errno; } @@ -366,248 +369,81 @@ grace_alarm_handler(int sig) * keys command helpers. */ if (getpgid(0) == getpid()) { - signal(SIGTERM, SIG_IGN); + ssh_signal(SIGTERM, SIG_IGN); kill(0, SIGTERM); } + /* XXX pre-format ipaddr/port so we don't need to access active_state */ /* Log error and exit. */ - sigdie("Timeout before authentication for %s", get_remote_ipaddr()); -} - -/* - * Signal handler for the key regeneration alarm. Note that this - * alarm only occurs in the daemon waiting for connections, and it does not - * do anything with the private key or random state before forking. - * Thus there should be no concurrency control/asynchronous execution - * problems. - */ -static void -generate_ephemeral_server_key(void) -{ - verbose("Generating %s%d bit RSA key.", - sensitive_data.server_key ? "new " : "", options.server_key_bits); - if (sensitive_data.server_key != NULL) - key_free(sensitive_data.server_key); - sensitive_data.server_key = key_generate(KEY_RSA1, - options.server_key_bits); - verbose("RSA key generation complete."); - - arc4random_buf(sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH); -} - -/*ARGSUSED*/ -static void -key_regeneration_alarm(int sig) -{ - int save_errno = errno; - - signal(SIGALRM, SIG_DFL); - errno = save_errno; - key_do_regen = 1; -} - -static void -sshd_exchange_identification(int sock_in, int sock_out) -{ - u_int i; - int mismatch; - int remote_major, remote_minor; - int major, minor; - char *s, *newline = "\n"; - char buf[256]; /* Must not be larger than remote_version. */ - char remote_version[256]; /* Must be at least as big as buf. */ - - if ((options.protocol & SSH_PROTO_1) && - (options.protocol & SSH_PROTO_2)) { - major = PROTOCOL_MAJOR_1; - minor = 99; - } else if (options.protocol & SSH_PROTO_2) { - major = PROTOCOL_MAJOR_2; - minor = PROTOCOL_MINOR_2; - newline = "\r\n"; - } else { - major = PROTOCOL_MAJOR_1; - minor = PROTOCOL_MINOR_1; - } - - xasprintf(&server_version_string, "SSH-%d.%d-%.100s%s%s%s", - major, minor, SSH_VERSION, - *options.version_addendum == '\0' ? "" : " ", - options.version_addendum, newline); - - /* Send our protocol version identification. */ - if (roaming_atomicio(vwrite, sock_out, server_version_string, - strlen(server_version_string)) - != strlen(server_version_string)) { - logit("Could not write ident string to %s", get_remote_ipaddr()); - cleanup_exit(255); - } - - /* Read other sides version identification. */ - memset(buf, 0, sizeof(buf)); - for (i = 0; i < sizeof(buf) - 1; i++) { - if (roaming_atomicio(read, sock_in, &buf[i], 1) != 1) { - logit("Did not receive identification string from %s", - get_remote_ipaddr()); - cleanup_exit(255); - } - if (buf[i] == '\r') { - buf[i] = 0; - /* Kludge for F-Secure Macintosh < 1.0.2 */ - if (i == 12 && - strncmp(buf, "SSH-1.5-W1.0", 12) == 0) - break; - continue; - } - if (buf[i] == '\n') { - buf[i] = 0; - break; - } - } - buf[sizeof(buf) - 1] = 0; - client_version_string = xstrdup(buf); - - /* - * Check that the versions match. In future this might accept - * several versions and set appropriate flags to handle them. - */ - if (sscanf(client_version_string, "SSH-%d.%d-%[^\n]\n", - &remote_major, &remote_minor, remote_version) != 3) { - s = "Protocol mismatch.\n"; - (void) atomicio(vwrite, sock_out, s, strlen(s)); - logit("Bad protocol version identification '%.100s' " - "from %s port %d", client_version_string, - get_remote_ipaddr(), get_remote_port()); - close(sock_in); - close(sock_out); - cleanup_exit(255); - } - debug("Client protocol version %d.%d; client software version %.100s", - remote_major, remote_minor, remote_version); - - active_state->compat = compat_datafellows(remote_version); - - if ((datafellows & SSH_BUG_PROBE) != 0) { - logit("probed from %s with %s. Don't panic.", - get_remote_ipaddr(), client_version_string); - cleanup_exit(255); - } - if ((datafellows & SSH_BUG_SCANNER) != 0) { - logit("scanned from %s with %s. Don't panic.", - get_remote_ipaddr(), client_version_string); - cleanup_exit(255); - } - if ((datafellows & SSH_BUG_RSASIGMD5) != 0) { - logit("Client version \"%.100s\" uses unsafe RSA signature " - "scheme; disabling use of RSA keys", remote_version); - } - if ((datafellows & SSH_BUG_DERIVEKEY) != 0) { - fatal("Client version \"%.100s\" uses unsafe key agreement; " - "refusing connection", remote_version); - } - - mismatch = 0; - switch (remote_major) { - case 1: - if (remote_minor == 99) { - if (options.protocol & SSH_PROTO_2) - enable_compat20(); - else - mismatch = 1; - break; - } - if (!(options.protocol & SSH_PROTO_1)) { - mismatch = 1; - break; - } - if (remote_minor < 3) { - packet_disconnect("Your ssh version is too old and " - "is no longer supported. Please install a newer version."); - } else if (remote_minor == 3) { - /* note that this disables agent-forwarding */ - enable_compat13(); - } - break; - case 2: - if (options.protocol & SSH_PROTO_2) { - enable_compat20(); - break; - } - /* FALLTHROUGH */ - default: - mismatch = 1; - break; - } - chop(server_version_string); - debug("Local version string %.200s", server_version_string); - - if (mismatch) { - s = "Protocol major versions differ.\n"; - (void) atomicio(vwrite, sock_out, s, strlen(s)); - close(sock_in); - close(sock_out); - logit("Protocol major versions differ for %s: %.200s vs. %.200s", - get_remote_ipaddr(), - server_version_string, client_version_string); - cleanup_exit(255); - } + sigdie("Timeout before authentication for %s port %d", + ssh_remote_ipaddr(the_active_state), + ssh_remote_port(the_active_state)); } /* Destroy the host and server keys. They will no longer be needed. */ void destroy_sensitive_data(void) { - int i; + u_int i; - if (sensitive_data.server_key) { - key_free(sensitive_data.server_key); - sensitive_data.server_key = NULL; - } for (i = 0; i < options.num_host_key_files; i++) { if (sensitive_data.host_keys[i]) { - key_free(sensitive_data.host_keys[i]); + sshkey_free(sensitive_data.host_keys[i]); sensitive_data.host_keys[i] = NULL; } if (sensitive_data.host_certificates[i]) { - key_free(sensitive_data.host_certificates[i]); + sshkey_free(sensitive_data.host_certificates[i]); sensitive_data.host_certificates[i] = NULL; } } - sensitive_data.ssh1_host_key = NULL; - explicit_bzero(sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH); } /* Demote private to public keys for network child */ void demote_sensitive_data(void) { - Key *tmp; - int i; - - if (sensitive_data.server_key) { - tmp = key_demote(sensitive_data.server_key); - key_free(sensitive_data.server_key); - sensitive_data.server_key = tmp; - } + struct sshkey *tmp; + u_int i; + int r; for (i = 0; i < options.num_host_key_files; i++) { if (sensitive_data.host_keys[i]) { - tmp = key_demote(sensitive_data.host_keys[i]); - key_free(sensitive_data.host_keys[i]); + if ((r = sshkey_from_private( + sensitive_data.host_keys[i], &tmp)) != 0) + fatal("could not demote host %s key: %s", + sshkey_type(sensitive_data.host_keys[i]), + ssh_err(r)); + sshkey_free(sensitive_data.host_keys[i]); sensitive_data.host_keys[i] = tmp; - if (tmp->type == KEY_RSA1) - sensitive_data.ssh1_host_key = tmp; } /* Certs do not need demotion */ } +} + +static void +reseed_prngs(void) +{ + u_int32_t rnd[256]; - /* We do not clear ssh1_host key and cookie. XXX - Okay Niels? */ +#ifdef WITH_OPENSSL + RAND_poll(); +#endif + arc4random_stir(); /* noop on recent arc4random() implementations */ + arc4random_buf(rnd, sizeof(rnd)); /* let arc4random notice PID change */ + +#ifdef WITH_OPENSSL + RAND_seed(rnd, sizeof(rnd)); + /* give libcrypto a chance to notice the PID change */ + if ((RAND_bytes((u_char *)rnd, 1)) != 1) + fatal("%s: RAND_bytes failed", __func__); +#endif + + explicit_bzero(rnd, sizeof(rnd)); } static void privsep_preauth_child(void) { - u_int32_t rnd[256]; gid_t gidset[1]; /* Enable challenge-response authentication for privilege separation */ @@ -615,45 +451,35 @@ privsep_preauth_child(void) #ifdef GSSAPI /* Cache supported mechanism OIDs for later use */ - if (options.gss_authentication) - ssh_gssapi_prepare_supported_oids(); + ssh_gssapi_prepare_supported_oids(); #endif - arc4random_stir(); - arc4random_buf(rnd, sizeof(rnd)); -#ifdef WITH_OPENSSL - RAND_seed(rnd, sizeof(rnd)); - if ((RAND_bytes((u_char *)rnd, 1)) != 1) - fatal("%s: RAND_bytes failed", __func__); -#endif - explicit_bzero(rnd, sizeof(rnd)); + reseed_prngs(); /* Demote the private keys to public keys. */ demote_sensitive_data(); - /* Change our root directory */ - if (chroot(_PATH_PRIVSEP_CHROOT_DIR) == -1) - fatal("chroot(\"%s\"): %s", _PATH_PRIVSEP_CHROOT_DIR, - strerror(errno)); - if (chdir("/") == -1) - fatal("chdir(\"/\"): %s", strerror(errno)); - - /* Drop our privileges */ - debug3("privsep user:group %u:%u", (u_int)privsep_pw->pw_uid, - (u_int)privsep_pw->pw_gid); -#if 0 - /* XXX not ready, too heavy after chroot */ - do_setusercontext(privsep_pw); -#else - gidset[0] = privsep_pw->pw_gid; - if (setgroups(1, gidset) < 0) - fatal("setgroups: %.100s", strerror(errno)); - permanently_set_uid(privsep_pw); -#endif + /* Demote the child */ + if (privsep_chroot) { + /* Change our root directory */ + if (chroot(_PATH_PRIVSEP_CHROOT_DIR) == -1) + fatal("chroot(\"%s\"): %s", _PATH_PRIVSEP_CHROOT_DIR, + strerror(errno)); + if (chdir("/") == -1) + fatal("chdir(\"/\"): %s", strerror(errno)); + + /* Drop our privileges */ + debug3("privsep user:group %u:%u", (u_int)privsep_pw->pw_uid, + (u_int)privsep_pw->pw_gid); + gidset[0] = privsep_pw->pw_gid; + if (setgroups(1, gidset) == -1) + fatal("setgroups: %.100s", strerror(errno)); + permanently_set_uid(privsep_pw); + } } static int -privsep_preauth(Authctxt *authctxt) +privsep_preauth(struct ssh *ssh) { int status, r; pid_t pid; @@ -662,7 +488,7 @@ privsep_preauth(Authctxt *authctxt) /* Set up unprivileged child process to deal with network data */ pmonitor = monitor_init(); /* Store a pointer to the kex for later rekeying */ - pmonitor->m_pkex = &active_state->kex; + pmonitor->m_pkex = &ssh->kex; if (use_privsep == PRIVSEP_ON) box = ssh_sandbox_init(pmonitor); @@ -683,13 +509,10 @@ privsep_preauth(Authctxt *authctxt) } if (box != NULL) ssh_sandbox_parent_preauth(box, pid); - monitor_child_preauth(authctxt, pmonitor); - - /* Sync memory */ - monitor_sync(pmonitor); + monitor_child_preauth(ssh, pmonitor); /* Wait for the child's exit status */ - while (waitpid(pid, &status, 0) < 0) { + while (waitpid(pid, &status, 0) == -1) { if (errno == EINTR) continue; pmonitor->m_pid = -1; @@ -715,9 +538,7 @@ privsep_preauth(Authctxt *authctxt) /* Arrange for logging to be sent to the monitor */ set_log_handler(mm_log_handler, pmonitor); - /* Demote the child */ - if (getuid() == 0 || geteuid() == 0) - privsep_preauth_child(); + privsep_preauth_child(); setproctitle("%s", "[net]"); if (box != NULL) ssh_sandbox_child(box); @@ -727,14 +548,12 @@ privsep_preauth(Authctxt *authctxt) } static void -privsep_postauth(Authctxt *authctxt) +privsep_postauth(struct ssh *ssh, Authctxt *authctxt) { - u_int32_t rnd[256]; - #ifdef DISABLE_FD_PASSING if (1) { #else - if (authctxt->pw->pw_uid == 0 || options.use_login) { + if (authctxt->pw->pw_uid == 0) { #endif /* File descriptor passing is broken or root login */ use_privsep = 0; @@ -749,8 +568,9 @@ privsep_postauth(Authctxt *authctxt) fatal("fork of unprivileged child failed"); else if (pmonitor->m_pid != 0) { verbose("User child is on pid %ld", (long)pmonitor->m_pid); - buffer_clear(&loginmsg); - monitor_child_postauth(pmonitor); + sshbuf_reset(loginmsg); + monitor_clear_keystate(ssh, pmonitor); + monitor_child_postauth(ssh, pmonitor); /* NEVERREACHED */ exit(0); @@ -764,39 +584,46 @@ privsep_postauth(Authctxt *authctxt) /* Demote the private keys to public keys. */ demote_sensitive_data(); - arc4random_stir(); - arc4random_buf(rnd, sizeof(rnd)); -#ifdef WITH_OPENSSL - RAND_seed(rnd, sizeof(rnd)); - if ((RAND_bytes((u_char *)rnd, 1)) != 1) - fatal("%s: RAND_bytes failed", __func__); -#endif - explicit_bzero(rnd, sizeof(rnd)); + reseed_prngs(); /* Drop privileges */ do_setusercontext(authctxt->pw); skip: /* It is safe now to apply the key state */ - monitor_apply_keystate(pmonitor); + monitor_apply_keystate(ssh, pmonitor); /* * Tell the packet layer that authentication was successful, since * this information is not part of the key state. */ - packet_set_authenticated(); + ssh_packet_set_authenticated(ssh); +} + +static void +append_hostkey_type(struct sshbuf *b, const char *s) +{ + int r; + + if (match_pattern_list(s, options.hostkeyalgorithms, 0) != 1) { + debug3("%s: %s key not permitted by HostkeyAlgorithms", + __func__, s); + return; + } + if ((r = sshbuf_putf(b, "%s%s", sshbuf_len(b) > 0 ? "," : "", s)) != 0) + fatal("%s: sshbuf_putf: %s", __func__, ssh_err(r)); } static char * list_hostkey_types(void) { - Buffer b; - const char *p; + struct sshbuf *b; + struct sshkey *key; char *ret; - int i; - Key *key; + u_int i; - buffer_init(&b); + if ((b = sshbuf_new()) == NULL) + fatal("%s: sshbuf_new failed", __func__); for (i = 0; i < options.num_host_key_files; i++) { key = sensitive_data.host_keys[i]; if (key == NULL) @@ -805,13 +632,17 @@ list_hostkey_types(void) continue; switch (key->type) { case KEY_RSA: + /* for RSA we also support SHA2 signatures */ + append_hostkey_type(b, "rsa-sha2-512"); + append_hostkey_type(b, "rsa-sha2-256"); + /* FALLTHROUGH */ case KEY_DSA: case KEY_ECDSA: case KEY_ED25519: - if (buffer_len(&b) > 0) - buffer_append(&b, ",", 1); - p = key_ssh_name(key); - buffer_append(&b, p, strlen(p)); + case KEY_ECDSA_SK: + case KEY_ED25519_SK: + case KEY_XMSS: + append_hostkey_type(b, sshkey_ssh_name(key)); break; } /* If the private key has a cert peer, then list that too */ @@ -819,40 +650,45 @@ list_hostkey_types(void) if (key == NULL) continue; switch (key->type) { - case KEY_RSA_CERT_V00: - case KEY_DSA_CERT_V00: case KEY_RSA_CERT: + /* for RSA we also support SHA2 signatures */ + append_hostkey_type(b, + "rsa-sha2-512-cert-v01@openssh.com"); + append_hostkey_type(b, + "rsa-sha2-256-cert-v01@openssh.com"); + /* FALLTHROUGH */ case KEY_DSA_CERT: case KEY_ECDSA_CERT: case KEY_ED25519_CERT: - if (buffer_len(&b) > 0) - buffer_append(&b, ",", 1); - p = key_ssh_name(key); - buffer_append(&b, p, strlen(p)); + case KEY_ECDSA_SK_CERT: + case KEY_ED25519_SK_CERT: + case KEY_XMSS_CERT: + append_hostkey_type(b, sshkey_ssh_name(key)); break; } } - buffer_append(&b, "\0", 1); - ret = xstrdup(buffer_ptr(&b)); - buffer_free(&b); - debug("list_hostkey_types: %s", ret); + if ((ret = sshbuf_dup_string(b)) == NULL) + fatal("%s: sshbuf_dup_string failed", __func__); + sshbuf_free(b); + debug("%s: %s", __func__, ret); return ret; } -static Key * +static struct sshkey * get_hostkey_by_type(int type, int nid, int need_private, struct ssh *ssh) { - int i; - Key *key; + u_int i; + struct sshkey *key; for (i = 0; i < options.num_host_key_files; i++) { switch (type) { - case KEY_RSA_CERT_V00: - case KEY_DSA_CERT_V00: case KEY_RSA_CERT: case KEY_DSA_CERT: case KEY_ECDSA_CERT: case KEY_ED25519_CERT: + case KEY_ECDSA_SK_CERT: + case KEY_ED25519_SK_CERT: + case KEY_XMSS_CERT: key = sensitive_data.host_certificates[i]; break; default: @@ -861,49 +697,59 @@ get_hostkey_by_type(int type, int nid, int need_private, struct ssh *ssh) key = sensitive_data.host_pubkeys[i]; break; } - if (key != NULL && key->type == type && - (key->type != KEY_ECDSA || key->ecdsa_nid == nid)) + if (key == NULL || key->type != type) + continue; + switch (type) { + case KEY_ECDSA: + case KEY_ECDSA_SK: + case KEY_ECDSA_CERT: + case KEY_ECDSA_SK_CERT: + if (key->ecdsa_nid != nid) + continue; + /* FALLTHROUGH */ + default: return need_private ? sensitive_data.host_keys[i] : key; + } } return NULL; } -Key * +struct sshkey * get_hostkey_public_by_type(int type, int nid, struct ssh *ssh) { return get_hostkey_by_type(type, nid, 0, ssh); } -Key * +struct sshkey * get_hostkey_private_by_type(int type, int nid, struct ssh *ssh) { return get_hostkey_by_type(type, nid, 1, ssh); } -Key * +struct sshkey * get_hostkey_by_index(int ind) { - if (ind < 0 || ind >= options.num_host_key_files) + if (ind < 0 || (u_int)ind >= options.num_host_key_files) return (NULL); return (sensitive_data.host_keys[ind]); } -Key * +struct sshkey * get_hostkey_public_by_index(int ind, struct ssh *ssh) { - if (ind < 0 || ind >= options.num_host_key_files) + if (ind < 0 || (u_int)ind >= options.num_host_key_files) return (NULL); return (sensitive_data.host_pubkeys[ind]); } int -get_hostkey_index(Key *key, int compare, struct ssh *ssh) +get_hostkey_index(struct sshkey *key, int compare, struct ssh *ssh) { - int i; + u_int i; for (i = 0; i < options.num_host_key_files; i++) { - if (key_is_cert(key)) { + if (sshkey_is_cert(key)) { if (key == sensitive_data.host_certificates[i] || (compare && sensitive_data.host_certificates[i] && sshkey_equal(key, @@ -929,15 +775,20 @@ notify_hostkeys(struct ssh *ssh) { struct sshbuf *buf; struct sshkey *key; - int i, nkeys, r; + u_int i, nkeys; + int r; char *fp; + /* Some clients cannot cope with the hostkeys message, skip those. */ + if (ssh->compat & SSH_BUG_HOSTKEYS) + return; + if ((buf = sshbuf_new()) == NULL) fatal("%s: sshbuf_new", __func__); for (i = nkeys = 0; i < options.num_host_key_files; i++) { key = get_hostkey_public_by_index(i, ssh); if (key == NULL || key->type == KEY_UNSPEC || - key->type == KEY_RSA1 || sshkey_is_cert(key)) + sshkey_is_cert(key)) continue; fp = sshkey_fingerprint(key, options.fingerprint_hash, SSH_FP_DEFAULT); @@ -945,21 +796,29 @@ notify_hostkeys(struct ssh *ssh) sshkey_ssh_name(key), fp); free(fp); if (nkeys == 0) { - packet_start(SSH2_MSG_GLOBAL_REQUEST); - packet_put_cstring("hostkeys-00@openssh.com"); - packet_put_char(0); /* want-reply */ + /* + * Start building the request when we find the + * first usable key. + */ + if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 || + (r = sshpkt_put_cstring(ssh, "hostkeys-00@openssh.com")) != 0 || + (r = sshpkt_put_u8(ssh, 0)) != 0) /* want reply */ + sshpkt_fatal(ssh, r, "%s: start request", __func__); } + /* Append the key to the request */ sshbuf_reset(buf); if ((r = sshkey_putb(key, buf)) != 0) fatal("%s: couldn't put hostkey %d: %s", __func__, i, ssh_err(r)); - packet_put_string(sshbuf_ptr(buf), sshbuf_len(buf)); + if ((r = sshpkt_put_stringb(ssh, buf)) != 0) + sshpkt_fatal(ssh, r, "%s: append key", __func__); nkeys++; } - debug3("%s: sent %d hostkeys", __func__, nkeys); + debug3("%s: sent %u hostkeys", __func__, nkeys); if (nkeys == 0) fatal("%s: no hostkeys", __func__); - packet_send(); + if ((r = sshpkt_send(ssh)) != 0) + sshpkt_fatal(ssh, r, "%s: send", __func__); sshbuf_free(buf); } @@ -997,115 +856,108 @@ usage(void) fprintf(stderr, "%s, %s\n", SSH_RELEASE, #ifdef WITH_OPENSSL - SSLeay_version(SSLEAY_VERSION) + OpenSSL_version(OPENSSL_VERSION) #else "without OpenSSL" #endif ); fprintf(stderr, -"usage: sshd [-46DdeiqTt] [-b bits] [-C connection_spec] [-c host_cert_file]\n" +"usage: sshd [-46DdeiqTt] [-C connection_spec] [-c host_cert_file]\n" " [-E log_file] [-f config_file] [-g login_grace_time]\n" -" [-h host_key_file] [-k key_gen_time] [-o option] [-p port]\n" -" [-u len]\n" +" [-h host_key_file] [-o option] [-p port] [-u len]\n" ); exit(1); } static void -send_rexec_state(int fd, Buffer *conf) +send_rexec_state(int fd, struct sshbuf *conf) { - Buffer m; + struct sshbuf *m = NULL, *inc = NULL; + struct include_item *item = NULL; + int r; + + debug3("%s: entering fd = %d config len %zu", __func__, fd, + sshbuf_len(conf)); - debug3("%s: entering fd = %d config len %d", __func__, fd, - buffer_len(conf)); + if ((m = sshbuf_new()) == NULL || (inc = sshbuf_new()) == NULL) + fatal("%s: sshbuf_new failed", __func__); + + /* pack includes into a string */ + TAILQ_FOREACH(item, &includes, entry) { + if ((r = sshbuf_put_cstring(inc, item->selector)) != 0 || + (r = sshbuf_put_cstring(inc, item->filename)) != 0 || + (r = sshbuf_put_stringb(inc, item->contents)) != 0) + fatal("%s: buffer error: %s", __func__, ssh_err(r)); + } /* * Protocol from reexec master to child: * string configuration - * u_int ephemeral_key_follows - * bignum e (only if ephemeral_key_follows == 1) - * bignum n " - * bignum d " - * bignum iqmp " - * bignum p " - * bignum q " - * string rngseed (only if OpenSSL is not self-seeded) + * string included_files[] { + * string selector + * string filename + * string contents + * } + * string rng_seed (if required) */ - buffer_init(&m); - buffer_put_cstring(&m, buffer_ptr(conf)); - -#ifdef WITH_SSH1 - if (sensitive_data.server_key != NULL && - sensitive_data.server_key->type == KEY_RSA1) { - buffer_put_int(&m, 1); - buffer_put_bignum(&m, sensitive_data.server_key->rsa->e); - buffer_put_bignum(&m, sensitive_data.server_key->rsa->n); - buffer_put_bignum(&m, sensitive_data.server_key->rsa->d); - buffer_put_bignum(&m, sensitive_data.server_key->rsa->iqmp); - buffer_put_bignum(&m, sensitive_data.server_key->rsa->p); - buffer_put_bignum(&m, sensitive_data.server_key->rsa->q); - } else -#endif - buffer_put_int(&m, 0); - + if ((r = sshbuf_put_stringb(m, conf)) != 0 || + (r = sshbuf_put_stringb(m, inc)) != 0) + fatal("%s: buffer error: %s", __func__, ssh_err(r)); #if defined(WITH_OPENSSL) && !defined(OPENSSL_PRNG_ONLY) - rexec_send_rng_seed(&m); + rexec_send_rng_seed(m); #endif - - if (ssh_msg_send(fd, 0, &m) == -1) + if (ssh_msg_send(fd, 0, m) == -1) fatal("%s: ssh_msg_send failed", __func__); - buffer_free(&m); + sshbuf_free(m); + sshbuf_free(inc); debug3("%s: done", __func__); } static void -recv_rexec_state(int fd, Buffer *conf) +recv_rexec_state(int fd, struct sshbuf *conf) { - Buffer m; - char *cp; - u_int len; + struct sshbuf *m, *inc; + u_char *cp, ver; + size_t len; + int r; + struct include_item *item; debug3("%s: entering fd = %d", __func__, fd); - buffer_init(&m); - - if (ssh_msg_recv(fd, &m) == -1) + if ((m = sshbuf_new()) == NULL || (inc = sshbuf_new()) == NULL) + fatal("%s: sshbuf_new failed", __func__); + if (ssh_msg_recv(fd, m) == -1) fatal("%s: ssh_msg_recv failed", __func__); - if (buffer_get_char(&m) != 0) + if ((r = sshbuf_get_u8(m, &ver)) != 0) + fatal("%s: buffer error: %s", __func__, ssh_err(r)); + if (ver != 0) fatal("%s: rexec version mismatch", __func__); - - cp = buffer_get_string(&m, &len); - if (conf != NULL) - buffer_append(conf, cp, len + 1); - free(cp); - - if (buffer_get_int(&m)) { -#ifdef WITH_SSH1 - if (sensitive_data.server_key != NULL) - key_free(sensitive_data.server_key); - sensitive_data.server_key = key_new_private(KEY_RSA1); - buffer_get_bignum(&m, sensitive_data.server_key->rsa->e); - buffer_get_bignum(&m, sensitive_data.server_key->rsa->n); - buffer_get_bignum(&m, sensitive_data.server_key->rsa->d); - buffer_get_bignum(&m, sensitive_data.server_key->rsa->iqmp); - buffer_get_bignum(&m, sensitive_data.server_key->rsa->p); - buffer_get_bignum(&m, sensitive_data.server_key->rsa->q); - if (rsa_generate_additional_parameters( - sensitive_data.server_key->rsa) != 0) - fatal("%s: rsa_generate_additional_parameters " - "error", __func__); -#else - fatal("ssh1 not supported"); -#endif - } + if ((r = sshbuf_get_string(m, &cp, &len)) != 0 || + (r = sshbuf_get_stringb(m, inc)) != 0) + fatal("%s: buffer error: %s", __func__, ssh_err(r)); #if defined(WITH_OPENSSL) && !defined(OPENSSL_PRNG_ONLY) - rexec_recv_rng_seed(&m); + rexec_recv_rng_seed(m); #endif - buffer_free(&m); + if (conf != NULL && (r = sshbuf_put(conf, cp, len))) + fatal("%s: buffer error: %s", __func__, ssh_err(r)); + + while (sshbuf_len(inc) != 0) { + item = xcalloc(1, sizeof(*item)); + if ((item->contents = sshbuf_new()) == NULL) + fatal("%s: sshbuf_new failed", __func__); + if ((r = sshbuf_get_cstring(inc, &item->selector, NULL)) != 0 || + (r = sshbuf_get_cstring(inc, &item->filename, NULL)) != 0 || + (r = sshbuf_get_stringb(inc, item->contents)) != 0) + fatal("%s: buffer error: %s", __func__, ssh_err(r)); + TAILQ_INSERT_TAIL(&includes, item, entry); + } + + free(cp); + sshbuf_free(m); debug3("%s: done", __func__); } @@ -1116,14 +968,9 @@ server_accept_inetd(int *sock_in, int *sock_out) { int fd; - startup_pipe = -1; if (rexeced_flag) { close(REEXEC_CONFIG_PASS_FD); *sock_in = *sock_out = dup(STDIN_FILENO); - if (!debug_flag) { - startup_pipe = dup(REEXEC_STARTUP_PIPE_FD); - close(REEXEC_STARTUP_PIPE_FD); - } } else { *sock_in = dup(STDIN_FILENO); *sock_out = dup(STDOUT_FILENO); @@ -1148,13 +995,13 @@ server_accept_inetd(int *sock_in, int *sock_out) * Listen for TCP connections */ static void -server_listen(void) +listen_on_addrs(struct listenaddr *la) { - int ret, listen_sock, on = 1; + int ret, listen_sock; struct addrinfo *ai; char ntop[NI_MAXHOST], strport[NI_MAXSERV]; - for (ai = options.listen_addrs; ai; ai = ai->ai_next) { + for (ai = la->addrs; ai; ai = ai->ai_next) { if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) continue; if (num_listen_socks >= MAX_LISTEN_SOCKS) @@ -1170,7 +1017,7 @@ server_listen(void) /* Create socket for listening. */ listen_sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol); - if (listen_sock < 0) { + if (listen_sock == -1) { /* kernel may not support ipv6 */ verbose("socket: %.100s", strerror(errno)); continue; @@ -1179,13 +1026,18 @@ server_listen(void) close(listen_sock); continue; } - /* - * Set socket options. - * Allow local port reuse in TIME_WAIT. - */ - if (setsockopt(listen_sock, SOL_SOCKET, SO_REUSEADDR, - &on, sizeof(on)) == -1) - error("setsockopt SO_REUSEADDR: %s", strerror(errno)); + if (fcntl(listen_sock, F_SETFD, FD_CLOEXEC) == -1) { + verbose("socket: CLOEXEC: %s", strerror(errno)); + close(listen_sock); + continue; + } + /* Socket options */ + set_reuseaddr(listen_sock); + if (la->rdomain != NULL && + set_rdomain(listen_sock, la->rdomain) == -1) { + close(listen_sock); + continue; + } /* Only communicate in IPv6 over AF_INET6 sockets. */ if (ai->ai_family == AF_INET6) @@ -1194,7 +1046,7 @@ server_listen(void) debug("Bind to port %s on %s.", strport, ntop); /* Bind the socket to the desired port. */ - if (bind(listen_sock, ai->ai_addr, ai->ai_addrlen) < 0) { + if (bind(listen_sock, ai->ai_addr, ai->ai_addrlen) == -1) { error("Bind to port %s on %s failed: %.200s.", strport, ntop, strerror(errno)); close(listen_sock); @@ -1204,12 +1056,31 @@ server_listen(void) num_listen_socks++; /* Start listening on the port. */ - if (listen(listen_sock, SSH_LISTEN_BACKLOG) < 0) + if (listen(listen_sock, SSH_LISTEN_BACKLOG) == -1) fatal("listen on [%s]:%s: %.100s", ntop, strport, strerror(errno)); - logit("Server listening on %s port %s.", ntop, strport); + logit("Server listening on %s port %s%s%s.", + ntop, strport, + la->rdomain == NULL ? "" : " rdomain ", + la->rdomain == NULL ? "" : la->rdomain); + } +} + +static void +server_listen(void) +{ + u_int i; + + for (i = 0; i < options.num_listen_addrs; i++) { + listen_on_addrs(&options.listen_addrs[i]); + freeaddrinfo(options.listen_addrs[i].addrs); + free(options.listen_addrs[i].rdomain); + memset(&options.listen_addrs[i], 0, + sizeof(options.listen_addrs[i])); } - freeaddrinfo(options.listen_addrs); + free(options.listen_addrs); + options.listen_addrs = NULL; + options.num_listen_addrs = 0; if (!num_listen_socks) fatal("Cannot bind any address."); @@ -1224,8 +1095,9 @@ server_accept_loop(int *sock_in, int *sock_out, int *newsock, int *config_s) { fd_set *fdset; int i, j, ret, maxfd; - int key_used = 0, startups = 0; + int ostartups = -1, startups = 0, listening = 0, lameduck = 0; int startup_p[2] = { -1 , -1 }; + char c = 0; struct sockaddr_storage from; socklen_t fromlen; pid_t pid; @@ -1237,8 +1109,9 @@ server_accept_loop(int *sock_in, int *sock_out, int *newsock, int *config_s) for (i = 0; i < num_listen_socks; i++) if (listen_socks[i] > maxfd) maxfd = listen_socks[i]; - /* pipes connected to unauthenticated childs */ + /* pipes connected to unauthenticated child sshd processes */ startup_pipes = xcalloc(options.max_startups, sizeof(int)); + startup_flags = xcalloc(options.max_startups, sizeof(int)); for (i = 0; i < options.max_startups; i++) startup_pipes[i] = -1; @@ -1247,11 +1120,23 @@ server_accept_loop(int *sock_in, int *sock_out, int *newsock, int *config_s) * the daemon is killed with a signal. */ for (;;) { - if (received_sighup) - sighup_restart(); - if (fdset != NULL) - free(fdset); - fdset = (fd_set *)xcalloc(howmany(maxfd + 1, NFDBITS), + if (ostartups != startups) { + setproctitle("%s [listener] %d of %d-%d startups", + listener_proctitle, startups, + options.max_startups_begin, options.max_startups); + ostartups = startups; + } + if (received_sighup) { + if (!lameduck) { + debug("Received SIGHUP; waiting for children"); + close_listen_socks(); + lameduck = 1; + } + if (listening <= 0) + sighup_restart(); + } + free(fdset); + fdset = xcalloc(howmany(maxfd + 1, NFDBITS), sizeof(fd_mask)); for (i = 0; i < num_listen_socks; i++) @@ -1262,7 +1147,7 @@ server_accept_loop(int *sock_in, int *sock_out, int *newsock, int *config_s) /* Wait in select until there is a connection. */ ret = select(maxfd+1, fdset, NULL, NULL, NULL); - if (ret < 0 && errno != EINTR) + if (ret == -1 && errno != EINTR) error("select: %.100s", strerror(errno)); if (received_sigterm) { logit("Received signal %d; terminating.", @@ -1272,34 +1157,47 @@ server_accept_loop(int *sock_in, int *sock_out, int *newsock, int *config_s) unlink(options.pid_file); exit(received_sigterm == SIGTERM ? 0 : 255); } - if (key_used && key_do_regen) { - generate_ephemeral_server_key(); - key_used = 0; - key_do_regen = 0; - } - if (ret < 0) + if (ret == -1) continue; - for (i = 0; i < options.max_startups; i++) - if (startup_pipes[i] != -1 && - FD_ISSET(startup_pipes[i], fdset)) { - /* - * the read end of the pipe is ready - * if the child has closed the pipe - * after successful authentication - * or if the child has died - */ + for (i = 0; i < options.max_startups; i++) { + if (startup_pipes[i] == -1 || + !FD_ISSET(startup_pipes[i], fdset)) + continue; + switch (read(startup_pipes[i], &c, sizeof(c))) { + case -1: + if (errno == EINTR || errno == EAGAIN) + continue; + if (errno != EPIPE) { + error("%s: startup pipe %d (fd=%d): " + "read %s", __func__, i, + startup_pipes[i], strerror(errno)); + } + /* FALLTHROUGH */ + case 0: + /* child exited or completed auth */ close(startup_pipes[i]); startup_pipes[i] = -1; startups--; + if (startup_flags[i]) + listening--; + break; + case 1: + /* child has finished preliminaries */ + if (startup_flags[i]) { + listening--; + startup_flags[i] = 0; + } + break; } + } for (i = 0; i < num_listen_socks; i++) { if (!FD_ISSET(listen_socks[i], fdset)) continue; fromlen = sizeof(from); *newsock = accept(listen_socks[i], (struct sockaddr *)&from, &fromlen); - if (*newsock < 0) { + if (*newsock == -1) { if (errno != EINTR && errno != EWOULDBLOCK && errno != ECONNABORTED && errno != EAGAIN) error("accept: %.100s", @@ -1313,7 +1211,18 @@ server_accept_loop(int *sock_in, int *sock_out, int *newsock, int *config_s) continue; } if (drop_connection(startups) == 1) { - debug("drop connection #%d", startups); + char *laddr = get_local_ipaddr(*newsock); + char *raddr = get_peer_ipaddr(*newsock); + char msg[] = "Exceeded MaxStartups\r\n"; + + verbose("drop connection #%d from [%s]:%d " + "on [%s]:%d past MaxStartups", startups, + raddr, get_peer_port(*newsock), + laddr, get_local_port(*newsock)); + free(laddr); + free(raddr); + /* best-effort notification to client */ + (void)write(*newsock, msg, strlen(msg)); close(*newsock); continue; } @@ -1338,6 +1247,7 @@ server_accept_loop(int *sock_in, int *sock_out, int *newsock, int *config_s) if (maxfd < startup_p[0]) maxfd = startup_p[0]; startups++; + startup_flags[j] = 1; break; } @@ -1360,11 +1270,10 @@ server_accept_loop(int *sock_in, int *sock_out, int *newsock, int *config_s) startup_pipe = -1; pid = getpid(); if (rexec_flag) { - send_rexec_state(config_s[0], - &cfg); + send_rexec_state(config_s[0], cfg); close(config_s[0]); } - break; + return; } /* @@ -1373,13 +1282,14 @@ server_accept_loop(int *sock_in, int *sock_out, int *newsock, int *config_s) * parent continues listening. */ platform_pre_fork(); + listening++; if ((pid = fork()) == 0) { /* * Child. Close the listening and * max_startup sockets. Start using * the accepted socket. Reinitialize * logging (since our pid has changed). - * We break out of the loop to handle + * We return from this function to handle * the connection. */ platform_post_fork_child(); @@ -1394,12 +1304,23 @@ server_accept_loop(int *sock_in, int *sock_out, int *newsock, int *config_s) log_stderr); if (rexec_flag) close(config_s[0]); - break; + else { + /* + * Signal parent that the preliminaries + * for this child are complete. For the + * re-exec case, this happens after the + * child has received the rexec state + * from the server. + */ + (void)atomicio(vwrite, startup_pipe, + "\0", 1); + } + return; } /* Parent. Stay in the loop. */ platform_post_fork_parent(pid); - if (pid < 0) + if (pid == -1) error("fork: %.100s", strerror(errno)); else debug("Forked child %ld.", (long)pid); @@ -1407,23 +1328,10 @@ server_accept_loop(int *sock_in, int *sock_out, int *newsock, int *config_s) close(startup_p[1]); if (rexec_flag) { - send_rexec_state(config_s[0], &cfg); + send_rexec_state(config_s[0], cfg); close(config_s[0]); close(config_s[1]); } - - /* - * Mark that the key has been used (it - * was "given" to the child). - */ - if ((options.protocol & SSH_PROTO_1) && - key_used == 0) { - /* Schedule server key regeneration alarm. */ - signal(SIGALRM, key_regeneration_alarm); - alarm(options.key_regeneration_time); - key_used = 1; - } - close(*newsock); /* @@ -1439,13 +1347,138 @@ server_accept_loop(int *sock_in, int *sock_out, int *newsock, int *config_s) #endif explicit_bzero(rnd, sizeof(rnd)); } + } +} - /* child process check (or debug mode) */ - if (num_listen_socks < 0) - break; +/* + * If IP options are supported, make sure there are none (log and + * return an error if any are found). Basically we are worried about + * source routing; it can be used to pretend you are somebody + * (ip-address) you are not. That itself may be "almost acceptable" + * under certain circumstances, but rhosts authentication is useless + * if source routing is accepted. Notice also that if we just dropped + * source routing here, the other side could use IP spoofing to do + * rest of the interaction and could still bypass security. So we + * exit here if we detect any IP options. + */ +static void +check_ip_options(struct ssh *ssh) +{ +#ifdef IP_OPTIONS + int sock_in = ssh_packet_get_connection_in(ssh); + struct sockaddr_storage from; + u_char opts[200]; + socklen_t i, option_size = sizeof(opts), fromlen = sizeof(from); + char text[sizeof(opts) * 3 + 1]; + + memset(&from, 0, sizeof(from)); + if (getpeername(sock_in, (struct sockaddr *)&from, + &fromlen) == -1) + return; + if (from.ss_family != AF_INET) + return; + /* XXX IPv6 options? */ + + if (getsockopt(sock_in, IPPROTO_IP, IP_OPTIONS, opts, + &option_size) >= 0 && option_size != 0) { + text[0] = '\0'; + for (i = 0; i < option_size; i++) + snprintf(text + i*3, sizeof(text) - i*3, + " %2.2x", opts[i]); + fatal("Connection from %.100s port %d with IP opts: %.800s", + ssh_remote_ipaddr(ssh), ssh_remote_port(ssh), text); + } + return; +#endif /* IP_OPTIONS */ +} + +/* Set the routing domain for this process */ +static void +set_process_rdomain(struct ssh *ssh, const char *name) +{ +#if defined(HAVE_SYS_SET_PROCESS_RDOMAIN) + if (name == NULL) + return; /* default */ + + if (strcmp(name, "%D") == 0) { + /* "expands" to routing domain of connection */ + if ((name = ssh_packet_rdomain_in(ssh)) == NULL) + return; + } + /* NB. We don't pass 'ssh' to sys_set_process_rdomain() */ + return sys_set_process_rdomain(name); +#elif defined(__OpenBSD__) + int rtable, ortable = getrtable(); + const char *errstr; + + if (name == NULL) + return; /* default */ + + if (strcmp(name, "%D") == 0) { + /* "expands" to routing domain of connection */ + if ((name = ssh_packet_rdomain_in(ssh)) == NULL) + return; + } + + rtable = (int)strtonum(name, 0, 255, &errstr); + if (errstr != NULL) /* Shouldn't happen */ + fatal("Invalid routing domain \"%s\": %s", name, errstr); + if (rtable != ortable && setrtable(rtable) != 0) + fatal("Unable to set routing domain %d: %s", + rtable, strerror(errno)); + debug("%s: set routing domain %d (was %d)", __func__, rtable, ortable); +#else /* defined(__OpenBSD__) */ + fatal("Unable to set routing domain: not supported in this platform"); +#endif +} + +static void +accumulate_host_timing_secret(struct sshbuf *server_cfg, + struct sshkey *key) +{ + static struct ssh_digest_ctx *ctx; + u_char *hash; + size_t len; + struct sshbuf *buf; + int r; + + if (ctx == NULL && (ctx = ssh_digest_start(SSH_DIGEST_SHA512)) == NULL) + fatal("%s: ssh_digest_start", __func__); + if (key == NULL) { /* finalize */ + /* add server config in case we are using agent for host keys */ + if (ssh_digest_update(ctx, sshbuf_ptr(server_cfg), + sshbuf_len(server_cfg)) != 0) + fatal("%s: ssh_digest_update", __func__); + len = ssh_digest_bytes(SSH_DIGEST_SHA512); + hash = xmalloc(len); + if (ssh_digest_final(ctx, hash, len) != 0) + fatal("%s: ssh_digest_final", __func__); + options.timing_secret = PEEK_U64(hash); + freezero(hash, len); + ssh_digest_free(ctx); + ctx = NULL; + return; } + if ((buf = sshbuf_new()) == NULL) + fatal("%s could not allocate buffer", __func__); + if ((r = sshkey_private_serialize(key, buf)) != 0) + fatal("sshkey_private_serialize: %s", ssh_err(r)); + if (ssh_digest_update(ctx, sshbuf_ptr(buf), sshbuf_len(buf)) != 0) + fatal("%s: ssh_digest_update", __func__); + sshbuf_reset(buf); + sshbuf_free(buf); } +static char * +prepare_proctitle(int ac, char **av) +{ + char *ret = NULL; + int i; + + for (i = 0; i < ac; i++) + xextendf(&ret, " ", "%s", av[i]); + return ret; +} /* * Main program for the daemon. @@ -1453,22 +1486,22 @@ server_accept_loop(int *sock_in, int *sock_out, int *newsock, int *config_s) int main(int ac, char **av) { + struct ssh *ssh = NULL; extern char *optarg; extern int optind; - int r, opt, i, j, on = 1; + int r, opt, on = 1, already_daemon, remote_port; int sock_in = -1, sock_out = -1, newsock = -1; - const char *remote_ip; - int remote_port; - char *fp, *line, *logfile = NULL; + const char *remote_ip, *rdomain; + char *fp, *line, *laddr, *logfile = NULL; int config_s[2] = { -1 , -1 }; - u_int n; + u_int i, j; u_int64_t ibytes, obytes; mode_t new_umask; - Key *key; - Key *pubkey; + struct sshkey *key; + struct sshkey *pubkey; int keytype; Authctxt *authctxt; - struct connection_info *connection_info = get_connection_info(0, 0); + struct connection_info *connection_info = NULL; #ifdef HAVE_SECUREWARE (void)set_auth_parameters(ac, av); @@ -1479,7 +1512,7 @@ main(int ac, char **av) saved_argc = ac; rexec_argc = ac; saved_argv = xcalloc(ac + 1, sizeof(*saved_argv)); - for (i = 0; i < ac; i++) + for (i = 0; (int)i < ac; i++) saved_argv[i] = xstrdup(av[i]); saved_argv[i] = NULL; @@ -1495,11 +1528,14 @@ main(int ac, char **av) /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ sanitise_stdfd(); + seed_rng(); + /* Initialize configuration options to their default values. */ initialize_server_options(&options); /* Parse command-line arguments. */ - while ((opt = getopt(ac, av, "f:p:b:k:h:g:u:o:C:dDeE:iqrtQRT46")) != -1) { + while ((opt = getopt(ac, av, + "C:E:b:c:f:g:h:k:o:p:u:46DQRTdeiqrt")) != -1) { switch (opt) { case '4': options.address_family = AF_INET; @@ -1511,12 +1547,8 @@ main(int ac, char **av) config_file_name = optarg; break; case 'c': - if (options.num_host_cert_files >= MAX_HOSTCERTS) { - fprintf(stderr, "too many host certificates.\n"); - exit(1); - } - options.host_cert_files[options.num_host_cert_files++] = - derelativise_path(optarg); + servconf_add_hostcert("[command-line]", 0, + &options, optarg); break; case 'd': if (debug_flag == 0) { @@ -1529,7 +1561,7 @@ main(int ac, char **av) no_daemon_flag = 1; break; case 'E': - logfile = xstrdup(optarg); + logfile = optarg; /* FALLTHROUGH */ case 'e': log_stderr = 1; @@ -1551,8 +1583,7 @@ main(int ac, char **av) options.log_level = SYSLOG_LEVEL_QUIET; break; case 'b': - options.server_key_bits = (int)strtonum(optarg, 256, - 32768, NULL); + /* protocol 1, ignored */ break; case 'p': options.ports_from_cmdline = 1; @@ -1573,18 +1604,11 @@ main(int ac, char **av) } break; case 'k': - if ((options.key_regeneration_time = convtime(optarg)) == -1) { - fprintf(stderr, "Invalid key regeneration interval.\n"); - exit(1); - } + /* protocol 1, ignored */ break; case 'h': - if (options.num_host_key_files >= MAX_HOSTKEYS) { - fprintf(stderr, "too many host keys.\n"); - exit(1); - } - options.host_key_files[options.num_host_key_files++] = - derelativise_path(optarg); + servconf_add_hostkey("[command-line]", 0, + &options, optarg, 1); break; case 't': test_flag = 1; @@ -1593,6 +1617,7 @@ main(int ac, char **av) test_flag = 2; break; case 'C': + connection_info = get_connection_info(ssh, 0, 0); if (parse_server_match_testspec(connection_info, optarg) == -1) exit(1); @@ -1607,7 +1632,7 @@ main(int ac, char **av) case 'o': line = xstrdup(optarg); if (process_server_config_line(&options, line, - "command-line", 0, NULL, NULL) != 0) + "command-line", 0, NULL, NULL, &includes) != 0) exit(1); free(line); break; @@ -1619,22 +1644,16 @@ main(int ac, char **av) } if (rexeced_flag || inetd_flag) rexec_flag = 0; - if (!test_flag && (rexec_flag && (av[0] == NULL || *av[0] != '/'))) + if (!test_flag && rexec_flag && !path_absolute(av[0])) fatal("sshd re-exec requires execution with an absolute path"); if (rexeced_flag) closefrom(REEXEC_MIN_FREE_FD); else closefrom(REEXEC_DEVCRYPTO_RESERVED_FD); -#ifdef WITH_OPENSSL - OpenSSL_add_all_algorithms(); -#endif - /* If requested, redirect the logs to the specified logfile. */ - if (logfile != NULL) { + if (logfile != NULL) log_redirect_stderr_to(logfile); - free(logfile); - } /* * Force logging to stderr until we have loaded the private host * key (unless started from inetd) @@ -1644,7 +1663,7 @@ main(int ac, char **av) SYSLOG_LEVEL_INFO : options.log_level, options.log_facility == SYSLOG_FACILITY_NOT_SET ? SYSLOG_FACILITY_AUTH : options.log_facility, - log_stderr || !inetd_flag); + log_stderr || !inetd_flag || debug_flag); /* * Unset KRB5CCNAME, otherwise the user's session may inherit it from @@ -1653,41 +1672,35 @@ main(int ac, char **av) if (getenv("KRB5CCNAME") != NULL) (void) unsetenv("KRB5CCNAME"); -#ifdef _UNICOS - /* Cray can define user privs drop all privs now! - * Not needed on PRIV_SU systems! - */ - drop_cray_privs(); -#endif - - sensitive_data.server_key = NULL; - sensitive_data.ssh1_host_key = NULL; - sensitive_data.have_ssh1_key = 0; sensitive_data.have_ssh2_key = 0; /* - * If we're doing an extended config test, make sure we have all of - * the parameters we need. If we're not doing an extended test, - * do not silently ignore connection test params. + * If we're not doing an extended test do not silently ignore connection + * test params. */ - if (test_flag >= 2 && server_match_spec_complete(connection_info) == 0) - fatal("user, host and addr are all required when testing " - "Match configs"); - if (test_flag < 2 && server_match_spec_complete(connection_info) >= 0) + if (test_flag < 2 && connection_info != NULL) fatal("Config test connection parameter (-C) provided without " "test mode (-T)"); /* Fetch our configuration */ - buffer_init(&cfg); - if (rexeced_flag) - recv_rexec_state(REEXEC_CONFIG_PASS_FD, &cfg); - else - load_server_config(config_file_name, &cfg); + if ((cfg = sshbuf_new()) == NULL) + fatal("%s: sshbuf_new failed", __func__); + if (rexeced_flag) { + recv_rexec_state(REEXEC_CONFIG_PASS_FD, cfg); + if (!debug_flag) { + startup_pipe = dup(REEXEC_STARTUP_PIPE_FD); + close(REEXEC_STARTUP_PIPE_FD); + /* + * Signal parent that this child is at a point where + * they can go away if they have a SIGHUP pending. + */ + (void)atomicio(vwrite, startup_pipe, "\0", 1); + } + } else if (strcasecmp(config_file_name, "none") != 0) + load_server_config(config_file_name, cfg); parse_server_config(&options, rexeced_flag ? "rexec" : config_file_name, - &cfg, NULL); - - seed_rng(); + cfg, &includes, NULL); /* Fill in default values for those options not explicitly set. */ fill_default_server_options(&options); @@ -1702,6 +1715,11 @@ main(int ac, char **av) strcasecmp(options.authorized_keys_command, "none") != 0)) fatal("AuthorizedKeysCommand set without " "AuthorizedKeysCommandUser"); + if (options.authorized_principals_command_user == NULL && + (options.authorized_principals_command != NULL && + strcasecmp(options.authorized_principals_command, "none") != 0)) + fatal("AuthorizedPrincipalsCommand set without " + "AuthorizedPrincipalsCommandUser"); /* * Check whether there is any path through configured auth methods. @@ -1710,22 +1728,16 @@ main(int ac, char **av) * and warns for trivial misconfigurations that could break login. */ if (options.num_auth_methods != 0) { - if ((options.protocol & SSH_PROTO_1)) - fatal("AuthenticationMethods is not supported with " - "SSH protocol 1"); - for (n = 0; n < options.num_auth_methods; n++) { - if (auth2_methods_valid(options.auth_methods[n], + for (i = 0; i < options.num_auth_methods; i++) { + if (auth2_methods_valid(options.auth_methods[i], 1) == 0) break; } - if (n >= options.num_auth_methods) + if (i >= options.num_auth_methods) fatal("AuthenticationMethods cannot be satisfied by " "enabled authentication methods"); } - /* set default channel AF */ - channel_set_af(options.address_family); - /* Check that there are no remaining arguments. */ if (optind < ac) { fprintf(stderr, "Extra argument %s.\n", av[optind]); @@ -1734,26 +1746,21 @@ main(int ac, char **av) debug("sshd version %s, %s", SSH_VERSION, #ifdef WITH_OPENSSL - SSLeay_version(SSLEAY_VERSION) + OpenSSL_version(OPENSSL_VERSION) #else "without OpenSSL" #endif ); /* Store privilege separation user for later use if required. */ + privsep_chroot = use_privsep && (getuid() == 0 || geteuid() == 0); if ((privsep_pw = getpwnam(SSH_PRIVSEP_USER)) == NULL) { - if (use_privsep || options.kerberos_authentication) + if (privsep_chroot || options.kerberos_authentication) fatal("Privilege separation user %s does not exist", SSH_PRIVSEP_USER); } else { - if (privsep_pw->pw_passwd != NULL) { - explicit_bzero(privsep_pw->pw_passwd, - strlen(privsep_pw->pw_passwd)); - } privsep_pw = pwcopy(privsep_pw); - if (privsep_pw->pw_passwd != NULL) { - free(privsep_pw->pw_passwd); - } + freezero(privsep_pw->pw_passwd, strlen(privsep_pw->pw_passwd)); privsep_pw->pw_passwd = xstrdup("*"); } #if !defined(ANDROID) @@ -1762,9 +1769,9 @@ main(int ac, char **av) /* load host keys */ sensitive_data.host_keys = xcalloc(options.num_host_key_files, - sizeof(Key *)); + sizeof(struct sshkey *)); sensitive_data.host_pubkeys = xcalloc(options.num_host_key_files, - sizeof(Key *)); + sizeof(struct sshkey *)); if (options.host_key_agent) { if (strcmp(options.host_key_agent, SSH_AUTHSOCKET_ENV_NAME)) @@ -1778,24 +1785,48 @@ main(int ac, char **av) } for (i = 0; i < options.num_host_key_files; i++) { + int ll = options.host_key_file_userprovided[i] ? + SYSLOG_LEVEL_ERROR : SYSLOG_LEVEL_DEBUG1; + if (options.host_key_files[i] == NULL) continue; - key = key_load_private(options.host_key_files[i], "", NULL); - pubkey = key_load_public(options.host_key_files[i], NULL); + if ((r = sshkey_load_private(options.host_key_files[i], "", + &key, NULL)) != 0 && r != SSH_ERR_SYSTEM_ERROR) + do_log2(ll, "Unable to load host key \"%s\": %s", + options.host_key_files[i], ssh_err(r)); + if (sshkey_is_sk(key) && + key->sk_flags & SSH_SK_USER_PRESENCE_REQD) { + debug("host key %s requires user presence, ignoring", + options.host_key_files[i]); + key->sk_flags &= ~SSH_SK_USER_PRESENCE_REQD; + } + if (r == 0 && key != NULL && + (r = sshkey_shield_private(key)) != 0) { + do_log2(ll, "Unable to shield host key \"%s\": %s", + options.host_key_files[i], ssh_err(r)); + sshkey_free(key); + key = NULL; + } + if ((r = sshkey_load_public(options.host_key_files[i], + &pubkey, NULL)) != 0 && r != SSH_ERR_SYSTEM_ERROR) + do_log2(ll, "Unable to load host key \"%s\": %s", + options.host_key_files[i], ssh_err(r)); if (pubkey == NULL && key != NULL) - pubkey = key_demote(key); + if ((r = sshkey_from_private(key, &pubkey)) != 0) + fatal("Could not demote key: \"%s\": %s", + options.host_key_files[i], ssh_err(r)); sensitive_data.host_keys[i] = key; sensitive_data.host_pubkeys[i] = pubkey; - if (key == NULL && pubkey != NULL && pubkey->type != KEY_RSA1 && - have_agent) { + if (key == NULL && pubkey != NULL && have_agent) { debug("will rely on agent for hostkey %s", options.host_key_files[i]); keytype = pubkey->type; } else if (key != NULL) { keytype = key->type; + accumulate_host_timing_secret(cfg, key); } else { - error("Could not load host key: %s", + do_log2(ll, "Unable to load host key: %s", options.host_key_files[i]); sensitive_data.host_keys[i] = NULL; sensitive_data.host_pubkeys[i] = NULL; @@ -1803,14 +1834,13 @@ main(int ac, char **av) } switch (keytype) { - case KEY_RSA1: - sensitive_data.ssh1_host_key = key; - sensitive_data.have_ssh1_key = 1; - break; case KEY_RSA: case KEY_DSA: case KEY_ECDSA: case KEY_ED25519: + case KEY_ECDSA_SK: + case KEY_ED25519_SK: + case KEY_XMSS: if (have_agent || key != NULL) sensitive_data.have_ssh2_key = 1; break; @@ -1819,19 +1849,11 @@ main(int ac, char **av) SSH_FP_DEFAULT)) == NULL) fatal("sshkey_fingerprint failed"); debug("%s host key #%d: %s %s", - key ? "private" : "agent", i, keytype == KEY_RSA1 ? - sshkey_type(pubkey) : sshkey_ssh_name(pubkey), fp); + key ? "private" : "agent", i, sshkey_ssh_name(pubkey), fp); free(fp); } - if ((options.protocol & SSH_PROTO_1) && !sensitive_data.have_ssh1_key) { - logit("Disabling protocol version 1. Could not load host key"); - options.protocol &= ~SSH_PROTO_1; - } - if ((options.protocol & SSH_PROTO_2) && !sensitive_data.have_ssh2_key) { - logit("Disabling protocol version 2. Could not load host key"); - options.protocol &= ~SSH_PROTO_2; - } - if (!(options.protocol & (SSH_PROTO_1|SSH_PROTO_2))) { + accumulate_host_timing_secret(cfg, NULL); + if (!sensitive_data.have_ssh2_key) { logit("sshd: no hostkeys available -- exiting."); exit(1); } @@ -1841,28 +1863,28 @@ main(int ac, char **av) * indices to the public keys that they relate to. */ sensitive_data.host_certificates = xcalloc(options.num_host_key_files, - sizeof(Key *)); + sizeof(struct sshkey *)); for (i = 0; i < options.num_host_key_files; i++) sensitive_data.host_certificates[i] = NULL; for (i = 0; i < options.num_host_cert_files; i++) { if (options.host_cert_files[i] == NULL) continue; - key = key_load_public(options.host_cert_files[i], NULL); - if (key == NULL) { - error("Could not load host certificate: %s", - options.host_cert_files[i]); + if ((r = sshkey_load_public(options.host_cert_files[i], + &key, NULL)) != 0) { + error("Could not load host certificate \"%s\": %s", + options.host_cert_files[i], ssh_err(r)); continue; } - if (!key_is_cert(key)) { + if (!sshkey_is_cert(key)) { error("Certificate file is not a certificate: %s", options.host_cert_files[i]); - key_free(key); + sshkey_free(key); continue; } /* Find matching private key */ for (j = 0; j < options.num_host_key_files; j++) { - if (key_equal_public(key, + if (sshkey_equal_public(key, sensitive_data.host_keys[j])) { sensitive_data.host_certificates[j] = key; break; @@ -1871,42 +1893,15 @@ main(int ac, char **av) if (j >= options.num_host_key_files) { error("No matching private key for certificate: %s", options.host_cert_files[i]); - key_free(key); + sshkey_free(key); continue; } sensitive_data.host_certificates[j] = key; - debug("host certificate: #%d type %d %s", j, key->type, - key_type(key)); - } - -#ifdef WITH_SSH1 - /* Check certain values for sanity. */ - if (options.protocol & SSH_PROTO_1) { - if (options.server_key_bits < 512 || - options.server_key_bits > 32768) { - fprintf(stderr, "Bad server key size.\n"); - exit(1); - } - /* - * Check that server and host key lengths differ sufficiently. This - * is necessary to make double encryption work with rsaref. Oh, I - * hate software patents. I dont know if this can go? Niels - */ - if (options.server_key_bits > - BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) - - SSH_KEY_BITS_RESERVED && options.server_key_bits < - BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) + - SSH_KEY_BITS_RESERVED) { - options.server_key_bits = - BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) + - SSH_KEY_BITS_RESERVED; - debug("Forcing server key to %d bits to make it differ from host key.", - options.server_key_bits); - } + debug("host certificate: #%u type %d %s", j, key->type, + sshkey_type(key)); } -#endif - if (use_privsep) { + if (privsep_chroot) { struct stat st; if ((stat(_PATH_PRIVSEP_CHROOT_DIR, &st) == -1) || @@ -1926,8 +1921,14 @@ main(int ac, char **av) } if (test_flag > 1) { - if (server_match_spec_complete(connection_info) == 1) - parse_server_match_config(&options, connection_info); + /* + * If no connection info was provided by -C then use + * use a blank one that will cause no predicate to match. + */ + if (connection_info == NULL) + connection_info = get_connection_info(ssh, 0, 0); + connection_info->test = 1; + parse_server_match_config(&options, &includes, connection_info); dump_config(&options); } @@ -1946,14 +1947,17 @@ main(int ac, char **av) debug("setgroups() failed: %.200s", strerror(errno)); if (rexec_flag) { + if (rexec_argc < 0) + fatal("rexec_argc %d < 0", rexec_argc); rexec_argv = xcalloc(rexec_argc + 2, sizeof(char *)); - for (i = 0; i < rexec_argc; i++) { + for (i = 0; i < (u_int)rexec_argc; i++) { debug("rexec_argv[%d]='%s'", i, saved_argv[i]); rexec_argv[i] = saved_argv[i]; } rexec_argv[rexec_argc] = "-R"; rexec_argv[rexec_argc + 1] = NULL; } + listener_proctitle = prepare_proctitle(ac, av); /* Ensure that umask disallows at least group and world write */ new_umask = umask(0077) | 0022; @@ -1965,25 +1969,17 @@ main(int ac, char **av) log_init(__progname, options.log_level, options.log_facility, log_stderr); /* - * If not in debugging mode, and not started from inetd, disconnect - * from the controlling terminal, and fork. The original process - * exits. + * If not in debugging mode, not started from inetd and not already + * daemonized (eg re-exec via SIGHUP), disconnect from the controlling + * terminal, and fork. The original process exits. */ - if (!(debug_flag || inetd_flag || no_daemon_flag)) { -#ifdef TIOCNOTTY - int fd; -#endif /* TIOCNOTTY */ - if (daemon(0, 0) < 0) + already_daemon = daemonized(); + if (!(debug_flag || inetd_flag || no_daemon_flag || already_daemon)) { + + if (daemon(0, 0) == -1) fatal("daemon() failed: %.200s", strerror(errno)); - /* Disconnect from the controlling tty. */ -#ifdef TIOCNOTTY - fd = open(_PATH_TTY, O_RDWR | O_NOCTTY); - if (fd >= 0) { - (void) ioctl(fd, TIOCNOTTY, NULL); - close(fd); - } -#endif /* TIOCNOTTY */ + disconnect_controlling_tty(); } /* Reinitialize the log (because of the fork above). */ log_init(__progname, options.log_level, options.log_facility, log_stderr); @@ -1994,7 +1990,7 @@ main(int ac, char **av) error("chdir(\"/\"): %s", strerror(errno)); /* ignore SIGPIPE */ - signal(SIGPIPE, SIG_IGN); + ssh_signal(SIGPIPE, SIG_IGN); /* Get a connection, either from inetd or a listening TCP socket */ if (inetd_flag) { @@ -2003,13 +1999,10 @@ main(int ac, char **av) platform_pre_listen(); server_listen(); - if (options.protocol & SSH_PROTO_1) - generate_ephemeral_server_key(); - - signal(SIGHUP, sighup_handler); - signal(SIGCHLD, main_sigchld_handler); - signal(SIGTERM, sigterm_handler); - signal(SIGQUIT, sigterm_handler); + ssh_signal(SIGHUP, sighup_handler); + ssh_signal(SIGCHLD, main_sigchld_handler); + ssh_signal(SIGTERM, sigterm_handler); + ssh_signal(SIGQUIT, sigterm_handler); /* * Write out the pid file after the sigterm handler @@ -2046,7 +2039,7 @@ main(int ac, char **av) * controlling terminal which will result in "could not set * controlling tty" errors. */ - if (!debug_flag && !inetd_flag && setsid() < 0) + if (!debug_flag && !inetd_flag && setsid() == -1) error("setsid: %.100s", strerror(errno)); #endif @@ -2093,56 +2086,64 @@ main(int ac, char **av) fcntl(sock_out, F_SETFD, FD_CLOEXEC); fcntl(sock_in, F_SETFD, FD_CLOEXEC); - /* - * Disable the key regeneration alarm. We will not regenerate the - * key since we are no longer in a position to give it to anyone. We - * will not restart on SIGHUP since it no longer makes sense. - */ - alarm(0); - signal(SIGALRM, SIG_DFL); - signal(SIGHUP, SIG_DFL); - signal(SIGTERM, SIG_DFL); - signal(SIGQUIT, SIG_DFL); - signal(SIGCHLD, SIG_DFL); - signal(SIGINT, SIG_DFL); + /* We will not restart on SIGHUP since it no longer makes sense. */ + ssh_signal(SIGALRM, SIG_DFL); + ssh_signal(SIGHUP, SIG_DFL); + ssh_signal(SIGTERM, SIG_DFL); + ssh_signal(SIGQUIT, SIG_DFL); + ssh_signal(SIGCHLD, SIG_DFL); + ssh_signal(SIGINT, SIG_DFL); /* * Register our connection. This turns encryption off because we do * not have a key. */ - packet_set_connection(sock_in, sock_out); - packet_set_server(); + if ((ssh = ssh_packet_set_connection(NULL, sock_in, sock_out)) == NULL) + fatal("Unable to create connection"); + the_active_state = ssh; + ssh_packet_set_server(ssh); + + check_ip_options(ssh); + + /* Prepare the channels layer */ + channel_init_channels(ssh); + channel_set_af(ssh, options.address_family); + process_permitopen(ssh, &options); /* Set SO_KEEPALIVE if requested. */ - if (options.tcp_keep_alive && packet_connection_is_on_socket() && - setsockopt(sock_in, SOL_SOCKET, SO_KEEPALIVE, &on, sizeof(on)) < 0) + if (options.tcp_keep_alive && ssh_packet_connection_is_on_socket(ssh) && + setsockopt(sock_in, SOL_SOCKET, SO_KEEPALIVE, &on, sizeof(on)) == -1) error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno)); - if ((remote_port = get_remote_port()) < 0) { - debug("get_remote_port failed"); + if ((remote_port = ssh_remote_port(ssh)) < 0) { + debug("ssh_remote_port failed"); cleanup_exit(255); } - /* - * We use get_canonical_hostname with usedns = 0 instead of - * get_remote_ipaddr here so IP options will be checked. - */ - (void) get_canonical_hostname(0); + if (options.routing_domain != NULL) + set_process_rdomain(ssh, options.routing_domain); + /* * The rest of the code depends on the fact that - * get_remote_ipaddr() caches the remote ip, even if + * ssh_remote_ipaddr() caches the remote ip, even if * the socket goes away. */ - remote_ip = get_remote_ipaddr(); + remote_ip = ssh_remote_ipaddr(ssh); #ifdef SSH_AUDIT_EVENTS audit_connection_from(remote_ip, remote_port); #endif + rdomain = ssh_packet_rdomain_in(ssh); + /* Log the connection. */ - verbose("Connection from %s port %d on %s port %d", - remote_ip, remote_port, - get_local_ipaddr(sock_in), get_local_port()); + laddr = get_local_ipaddr(sock_in); + verbose("Connection from %s port %d on %s port %d%s%s%s", + remote_ip, remote_port, laddr, ssh_local_port(ssh), + rdomain == NULL ? "" : " rdomain \"", + rdomain == NULL ? "" : rdomain, + rdomain == NULL ? "" : "\""); + free(laddr); /* * We don't want to listen forever unless the other side @@ -2152,34 +2153,38 @@ main(int ac, char **av) * mode; it is just annoying to have the server exit just when you * are about to discover the bug. */ - signal(SIGALRM, grace_alarm_handler); + ssh_signal(SIGALRM, grace_alarm_handler); if (!debug_flag) alarm(options.login_grace_time); - sshd_exchange_identification(sock_in, sock_out); - - /* In inetd mode, generate ephemeral key only for proto 1 connections */ - if (!compat20 && inetd_flag && sensitive_data.server_key == NULL) - generate_ephemeral_server_key(); + if ((r = kex_exchange_identification(ssh, -1, + options.version_addendum)) != 0) + sshpkt_fatal(ssh, r, "banner exchange"); - packet_set_nonblocking(); + ssh_packet_set_nonblocking(ssh); /* allocate authentication context */ authctxt = xcalloc(1, sizeof(*authctxt)); + ssh->authctxt = authctxt; - authctxt->loginmsg = &loginmsg; + authctxt->loginmsg = loginmsg; /* XXX global for cleanup, access from other modules */ the_authctxt = authctxt; + /* Set default key authentication options */ + if ((auth_opts = sshauthopt_new_with_keys_defaults()) == NULL) + fatal("allocation failed"); + /* prepare buffer to collect messages to display to user after login */ - buffer_init(&loginmsg); + if ((loginmsg = sshbuf_new()) == NULL) + fatal("%s: sshbuf_new failed", __func__); auth_debug_reset(); if (use_privsep) { - if (privsep_preauth(authctxt) == 1) + if (privsep_preauth(ssh) == 1) goto authenticated; - } else if (compat20 && have_agent) { + } else if (have_agent) { if ((r = ssh_get_authentication_socket(&auth_sock)) != 0) { error("Unable to get agent socket: %s", ssh_err(r)); have_agent = 0; @@ -2188,23 +2193,16 @@ main(int ac, char **av) /* perform the key exchange */ /* authenticate user and start session */ - if (compat20) { - do_ssh2_kex(); - do_authentication2(authctxt); - } else { -#ifdef WITH_SSH1 - do_ssh1_kex(); - do_authentication(authctxt); -#else - fatal("ssh1 not supported"); -#endif - } + do_ssh2_kex(ssh); + do_authentication2(ssh); + /* * If we use privilege separation, the unprivileged child transfers * the current keystate and exits */ if (use_privsep) { - mm_send_keystate(pmonitor); + mm_send_keystate(ssh, pmonitor); + ssh_packet_clear_keys(ssh); exit(0); } @@ -2214,7 +2212,7 @@ main(int ac, char **av) * authentication. */ alarm(0); - signal(SIGALRM, SIG_DFL); + ssh_signal(SIGALRM, SIG_DFL); authctxt->authenticated = 1; if (startup_pipe != -1) { close(startup_pipe); @@ -2222,7 +2220,7 @@ main(int ac, char **av) } #ifdef SSH_AUDIT_EVENTS - audit_event(SSH_AUTH_SUCCESS); + audit_event(ssh, SSH_AUTH_SUCCESS); #endif #ifdef GSSAPI @@ -2235,7 +2233,7 @@ main(int ac, char **av) #ifdef USE_PAM if (options.use_pam) { do_pam_setcred(1); - do_pam_session(); + do_pam_session(ssh); } #endif @@ -2244,24 +2242,21 @@ main(int ac, char **av) * file descriptor passing. */ if (use_privsep) { - privsep_postauth(authctxt); + privsep_postauth(ssh, authctxt); /* the monitor process [priv] will not return */ - if (!compat20) - destroy_sensitive_data(); } - packet_set_timeout(options.client_alive_interval, + ssh_packet_set_timeout(ssh, options.client_alive_interval, options.client_alive_count_max); /* Try to send all our hostkeys to the client */ - if (compat20) - notify_hostkeys(active_state); + notify_hostkeys(ssh); /* Start session. */ - do_authenticated(authctxt); + do_authenticated(ssh, authctxt); /* The connection has been terminated. */ - packet_get_bytes(&ibytes, &obytes); + ssh_packet_get_bytes(ssh, &ibytes, &obytes); verbose("Transferred: sent %llu, received %llu bytes", (unsigned long long)obytes, (unsigned long long)ibytes); @@ -2273,10 +2268,10 @@ main(int ac, char **av) #endif /* USE_PAM */ #ifdef SSH_AUDIT_EVENTS - PRIVSEP(audit_event(SSH_CONNECTION_CLOSE)); + PRIVSEP(audit_event(ssh, SSH_CONNECTION_CLOSE)); #endif - packet_close(); + ssh_packet_close(ssh); if (use_privsep) mm_terminate(); @@ -2284,318 +2279,95 @@ main(int ac, char **av) exit(0); } -#ifdef WITH_SSH1 -/* - * Decrypt session_key_int using our private server key and private host key - * (key with larger modulus first). - */ int -ssh1_session_key(BIGNUM *session_key_int) +sshd_hostkey_sign(struct ssh *ssh, struct sshkey *privkey, + struct sshkey *pubkey, u_char **signature, size_t *slenp, + const u_char *data, size_t dlen, const char *alg) { - int rsafail = 0; - - if (BN_cmp(sensitive_data.server_key->rsa->n, - sensitive_data.ssh1_host_key->rsa->n) > 0) { - /* Server key has bigger modulus. */ - if (BN_num_bits(sensitive_data.server_key->rsa->n) < - BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) + - SSH_KEY_BITS_RESERVED) { - fatal("do_connection: %s: " - "server_key %d < host_key %d + SSH_KEY_BITS_RESERVED %d", - get_remote_ipaddr(), - BN_num_bits(sensitive_data.server_key->rsa->n), - BN_num_bits(sensitive_data.ssh1_host_key->rsa->n), - SSH_KEY_BITS_RESERVED); + int r; + + if (use_privsep) { + if (privkey) { + if (mm_sshkey_sign(ssh, privkey, signature, slenp, + data, dlen, alg, options.sk_provider, + ssh->compat) < 0) + fatal("%s: privkey sign failed", __func__); + } else { + if (mm_sshkey_sign(ssh, pubkey, signature, slenp, + data, dlen, alg, options.sk_provider, + ssh->compat) < 0) + fatal("%s: pubkey sign failed", __func__); } - if (rsa_private_decrypt(session_key_int, session_key_int, - sensitive_data.server_key->rsa) != 0) - rsafail++; - if (rsa_private_decrypt(session_key_int, session_key_int, - sensitive_data.ssh1_host_key->rsa) != 0) - rsafail++; } else { - /* Host key has bigger modulus (or they are equal). */ - if (BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) < - BN_num_bits(sensitive_data.server_key->rsa->n) + - SSH_KEY_BITS_RESERVED) { - fatal("do_connection: %s: " - "host_key %d < server_key %d + SSH_KEY_BITS_RESERVED %d", - get_remote_ipaddr(), - BN_num_bits(sensitive_data.ssh1_host_key->rsa->n), - BN_num_bits(sensitive_data.server_key->rsa->n), - SSH_KEY_BITS_RESERVED); + if (privkey) { + if (sshkey_sign(privkey, signature, slenp, data, dlen, + alg, options.sk_provider, ssh->compat) < 0) + fatal("%s: privkey sign failed", __func__); + } else { + if ((r = ssh_agent_sign(auth_sock, pubkey, + signature, slenp, data, dlen, alg, + ssh->compat)) != 0) { + fatal("%s: agent sign failed: %s", + __func__, ssh_err(r)); + } } - if (rsa_private_decrypt(session_key_int, session_key_int, - sensitive_data.ssh1_host_key->rsa) != 0) - rsafail++; - if (rsa_private_decrypt(session_key_int, session_key_int, - sensitive_data.server_key->rsa) != 0) - rsafail++; - } - return (rsafail); -} - -/* - * SSH1 key exchange - */ -static void -do_ssh1_kex(void) -{ - int i, len; - int rsafail = 0; - BIGNUM *session_key_int, *fake_key_int, *real_key_int; - u_char session_key[SSH_SESSION_KEY_LENGTH]; - u_char fake_key_bytes[4096 / 8]; - size_t fake_key_len; - u_char cookie[8]; - u_int cipher_type, auth_mask, protocol_flags; - - /* - * Generate check bytes that the client must send back in the user - * packet in order for it to be accepted; this is used to defy ip - * spoofing attacks. Note that this only works against somebody - * doing IP spoofing from a remote machine; any machine on the local - * network can still see outgoing packets and catch the random - * cookie. This only affects rhosts authentication, and this is one - * of the reasons why it is inherently insecure. - */ - arc4random_buf(cookie, sizeof(cookie)); - - /* - * Send our public key. We include in the packet 64 bits of random - * data that must be matched in the reply in order to prevent IP - * spoofing. - */ - packet_start(SSH_SMSG_PUBLIC_KEY); - for (i = 0; i < 8; i++) - packet_put_char(cookie[i]); - - /* Store our public server RSA key. */ - packet_put_int(BN_num_bits(sensitive_data.server_key->rsa->n)); - packet_put_bignum(sensitive_data.server_key->rsa->e); - packet_put_bignum(sensitive_data.server_key->rsa->n); - - /* Store our public host RSA key. */ - packet_put_int(BN_num_bits(sensitive_data.ssh1_host_key->rsa->n)); - packet_put_bignum(sensitive_data.ssh1_host_key->rsa->e); - packet_put_bignum(sensitive_data.ssh1_host_key->rsa->n); - - /* Put protocol flags. */ - packet_put_int(SSH_PROTOFLAG_HOST_IN_FWD_OPEN); - - /* Declare which ciphers we support. */ - packet_put_int(cipher_mask_ssh1(0)); - - /* Declare supported authentication types. */ - auth_mask = 0; - if (options.rhosts_rsa_authentication) - auth_mask |= 1 << SSH_AUTH_RHOSTS_RSA; - if (options.rsa_authentication) - auth_mask |= 1 << SSH_AUTH_RSA; - if (options.challenge_response_authentication == 1) - auth_mask |= 1 << SSH_AUTH_TIS; - if (options.password_authentication) - auth_mask |= 1 << SSH_AUTH_PASSWORD; - packet_put_int(auth_mask); - - /* Send the packet and wait for it to be sent. */ - packet_send(); - packet_write_wait(); - - debug("Sent %d bit server key and %d bit host key.", - BN_num_bits(sensitive_data.server_key->rsa->n), - BN_num_bits(sensitive_data.ssh1_host_key->rsa->n)); - - /* Read clients reply (cipher type and session key). */ - packet_read_expect(SSH_CMSG_SESSION_KEY); - - /* Get cipher type and check whether we accept this. */ - cipher_type = packet_get_char(); - - if (!(cipher_mask_ssh1(0) & (1 << cipher_type))) - packet_disconnect("Warning: client selects unsupported cipher."); - - /* Get check bytes from the packet. These must match those we - sent earlier with the public key packet. */ - for (i = 0; i < 8; i++) - if (cookie[i] != packet_get_char()) - packet_disconnect("IP Spoofing check bytes do not match."); - - debug("Encryption type: %.200s", cipher_name(cipher_type)); - - /* Get the encrypted integer. */ - if ((real_key_int = BN_new()) == NULL) - fatal("do_ssh1_kex: BN_new failed"); - packet_get_bignum(real_key_int); - - protocol_flags = packet_get_int(); - packet_set_protocol_flags(protocol_flags); - packet_check_eom(); - - /* Setup a fake key in case RSA decryption fails */ - if ((fake_key_int = BN_new()) == NULL) - fatal("do_ssh1_kex: BN_new failed"); - fake_key_len = BN_num_bytes(real_key_int); - if (fake_key_len > sizeof(fake_key_bytes)) - fake_key_len = sizeof(fake_key_bytes); - arc4random_buf(fake_key_bytes, fake_key_len); - if (BN_bin2bn(fake_key_bytes, fake_key_len, fake_key_int) == NULL) - fatal("do_ssh1_kex: BN_bin2bn failed"); - - /* Decrypt real_key_int using host/server keys */ - rsafail = PRIVSEP(ssh1_session_key(real_key_int)); - /* If decryption failed, use the fake key. Else, the real key. */ - if (rsafail) - session_key_int = fake_key_int; - else - session_key_int = real_key_int; - - /* - * Extract session key from the decrypted integer. The key is in the - * least significant 256 bits of the integer; the first byte of the - * key is in the highest bits. - */ - (void) BN_mask_bits(session_key_int, sizeof(session_key) * 8); - len = BN_num_bytes(session_key_int); - if (len < 0 || (u_int)len > sizeof(session_key)) { - error("do_ssh1_kex: bad session key len from %s: " - "session_key_int %d > sizeof(session_key) %lu", - get_remote_ipaddr(), len, (u_long)sizeof(session_key)); - rsafail++; - } else { - explicit_bzero(session_key, sizeof(session_key)); - BN_bn2bin(session_key_int, - session_key + sizeof(session_key) - len); - - derive_ssh1_session_id( - sensitive_data.ssh1_host_key->rsa->n, - sensitive_data.server_key->rsa->n, - cookie, session_id); - /* - * Xor the first 16 bytes of the session key with the - * session id. - */ - for (i = 0; i < 16; i++) - session_key[i] ^= session_id[i]; - } - - /* Destroy the private and public keys. No longer. */ - destroy_sensitive_data(); - - if (use_privsep) - mm_ssh1_session_id(session_id); - - /* Destroy the decrypted integer. It is no longer needed. */ - BN_clear_free(real_key_int); - BN_clear_free(fake_key_int); - - /* Set the session key. From this on all communications will be encrypted. */ - packet_set_encryption_key(session_key, SSH_SESSION_KEY_LENGTH, cipher_type); - - /* Destroy our copy of the session key. It is no longer needed. */ - explicit_bzero(session_key, sizeof(session_key)); - - debug("Received session key; encryption turned on."); - - /* Send an acknowledgment packet. Note that this packet is sent encrypted. */ - packet_start(SSH_SMSG_SUCCESS); - packet_send(); - packet_write_wait(); -} -#endif - -int -sshd_hostkey_sign(Key *privkey, Key *pubkey, u_char **signature, size_t *slen, - const u_char *data, size_t dlen, u_int flag) -{ - int r; - u_int xxx_slen, xxx_dlen = dlen; - - if (privkey) { - if (PRIVSEP(key_sign(privkey, signature, &xxx_slen, data, xxx_dlen) < 0)) - fatal("%s: key_sign failed", __func__); - if (slen) - *slen = xxx_slen; - } else if (use_privsep) { - if (mm_key_sign(pubkey, signature, &xxx_slen, data, xxx_dlen) < 0) - fatal("%s: pubkey_sign failed", __func__); - if (slen) - *slen = xxx_slen; - } else { - if ((r = ssh_agent_sign(auth_sock, pubkey, signature, slen, - data, dlen, datafellows)) != 0) - fatal("%s: ssh_agent_sign failed: %s", - __func__, ssh_err(r)); } return 0; } -/* - * SSH2 key exchange: diffie-hellman-group1-sha1 - */ +/* SSH2 key exchange */ static void -do_ssh2_kex(void) +do_ssh2_kex(struct ssh *ssh) { char *myproposal[PROPOSAL_MAX] = { KEX_SERVER }; struct kex *kex; int r; - if (options.ciphers != NULL) { - myproposal[PROPOSAL_ENC_ALGS_CTOS] = - myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers; - } - myproposal[PROPOSAL_ENC_ALGS_CTOS] = - compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]); - myproposal[PROPOSAL_ENC_ALGS_STOC] = - compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]); - - if (options.macs != NULL) { - myproposal[PROPOSAL_MAC_ALGS_CTOS] = - myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs; - } + myproposal[PROPOSAL_KEX_ALGS] = compat_kex_proposal( + options.kex_algorithms); + myproposal[PROPOSAL_ENC_ALGS_CTOS] = compat_cipher_proposal( + options.ciphers); + myproposal[PROPOSAL_ENC_ALGS_STOC] = compat_cipher_proposal( + options.ciphers); + myproposal[PROPOSAL_MAC_ALGS_CTOS] = + myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs; + if (options.compression == COMP_NONE) { myproposal[PROPOSAL_COMP_ALGS_CTOS] = - myproposal[PROPOSAL_COMP_ALGS_STOC] = "none"; - } else if (options.compression == COMP_DELAYED) { - myproposal[PROPOSAL_COMP_ALGS_CTOS] = - myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib@openssh.com"; + myproposal[PROPOSAL_COMP_ALGS_STOC] = "none"; } - if (options.kex_algorithms != NULL) - myproposal[PROPOSAL_KEX_ALGS] = options.kex_algorithms; - - myproposal[PROPOSAL_KEX_ALGS] = compat_kex_proposal( - myproposal[PROPOSAL_KEX_ALGS]); if (options.rekey_limit || options.rekey_interval) - packet_set_rekey_limits((u_int32_t)options.rekey_limit, - (time_t)options.rekey_interval); + ssh_packet_set_rekey_limits(ssh, options.rekey_limit, + options.rekey_interval); myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = compat_pkalg_proposal( list_hostkey_types()); /* start key exchange */ - if ((r = kex_setup(active_state, myproposal)) != 0) + if ((r = kex_setup(ssh, myproposal)) != 0) fatal("kex_setup: %s", ssh_err(r)); - kex = active_state->kex; + kex = ssh->kex; #ifdef WITH_OPENSSL - kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server; - kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server; + kex->kex[KEX_DH_GRP1_SHA1] = kex_gen_server; + kex->kex[KEX_DH_GRP14_SHA1] = kex_gen_server; + kex->kex[KEX_DH_GRP14_SHA256] = kex_gen_server; + kex->kex[KEX_DH_GRP16_SHA512] = kex_gen_server; + kex->kex[KEX_DH_GRP18_SHA512] = kex_gen_server; kex->kex[KEX_DH_GEX_SHA1] = kexgex_server; kex->kex[KEX_DH_GEX_SHA256] = kexgex_server; # ifdef OPENSSL_HAS_ECC - kex->kex[KEX_ECDH_SHA2] = kexecdh_server; + kex->kex[KEX_ECDH_SHA2] = kex_gen_server; # endif #endif - kex->kex[KEX_C25519_SHA256] = kexc25519_server; - kex->server = 1; - kex->client_version_string=client_version_string; - kex->server_version_string=server_version_string; + kex->kex[KEX_C25519_SHA256] = kex_gen_server; + kex->kex[KEX_KEM_SNTRUP4591761X25519_SHA512] = kex_gen_server; kex->load_host_public_key=&get_hostkey_public_by_type; kex->load_host_private_key=&get_hostkey_private_by_type; kex->host_key_index=&get_hostkey_index; kex->sign = sshd_hostkey_sign; - dispatch_run(DISPATCH_BLOCK, &kex->done, active_state); + ssh_dispatch_run_fatal(ssh, DISPATCH_BLOCK, &kex->done); session_id2 = kex->session_id; session_id2_len = kex->session_id_len; @@ -2614,8 +2386,8 @@ do_ssh2_kex(void) void cleanup_exit(int i) { - if (the_authctxt) { - do_cleanup(the_authctxt); + if (the_active_state != NULL && the_authctxt != NULL) { + do_cleanup(the_active_state, the_authctxt); if (use_privsep && privsep_is_preauth && pmonitor != NULL && pmonitor->m_pid > 1) { debug("Killing privsep child %d", pmonitor->m_pid); @@ -2627,8 +2399,8 @@ cleanup_exit(int i) } #ifdef SSH_AUDIT_EVENTS /* done after do_cleanup so it can cancel the PAM auth 'thread' */ - if (!use_privsep || mm_is_monitor()) - audit_event(SSH_CONNECTION_ABANDON); + if (the_active_state != NULL && (!use_privsep || mm_is_monitor())) + audit_event(the_active_state, SSH_CONNECTION_ABANDON); #endif _exit(i); } |