Date: Fri, 15 Apr 2022 14:41:28 GMT From: Ed Maste <emaste@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: 87c1498d1a74 - main - ssh: update to OpenSSH v9.0p1 Message-ID: <202204151441.23FEfSnn086228@gitrepo.freebsd.org>
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The branch main has been updated by emaste: URL: https://cgit.FreeBSD.org/src/commit/?id=87c1498d1a7473ff983e5c0456f30608f3f1e601 commit 87c1498d1a7473ff983e5c0456f30608f3f1e601 Merge: 10aa36702cdb 7f9f5c27f6f6 Author: Ed Maste <emaste@FreeBSD.org> AuthorDate: 2022-04-15 14:41:08 +0000 Commit: Ed Maste <emaste@FreeBSD.org> CommitDate: 2022-04-15 14:41:08 +0000 ssh: update to OpenSSH v9.0p1 Release notes are available at https://www.openssh.com/txt/release-9.0 Some highlights: * ssh(1), sshd(8): use the hybrid Streamlined NTRU Prime + x25519 key exchange method by default ("sntrup761x25519-sha512@openssh.com"). The NTRU algorithm is believed to resist attacks enabled by future quantum computers and is paired with the X25519 ECDH key exchange (the previous default) as a backstop against any weaknesses in NTRU Prime that may be discovered in the future. The combination ensures that the hybrid exchange offers at least as good security as the status quo. * sftp-server(8): support the "copy-data" extension to allow server- side copying of files/data, following the design in draft-ietf-secsh-filexfer-extensions-00. bz2948 * sftp(1): add a "cp" command to allow the sftp client to perform server-side file copies. This commit excludes the scp(1) change to use the SFTP protocol by default; that change will immediately follow. MFC after: 1 month Relnotes: Yes Sponsored by: The FreeBSD Foundation crypto/openssh/.depend | 2 +- crypto/openssh/.github/configs | 21 +- crypto/openssh/.github/setup_ci.sh | 25 +- crypto/openssh/.github/workflows/c-cpp.yml | 3 + crypto/openssh/.github/workflows/selfhosted.yml | 7 +- crypto/openssh/ChangeLog | 1092 +++++++++++------------ crypto/openssh/Makefile.in | 5 +- crypto/openssh/PROTOCOL | 41 +- crypto/openssh/README | 2 +- crypto/openssh/auth.c | 52 +- crypto/openssh/auth2-pubkey.c | 6 +- crypto/openssh/channels.c | 222 ++--- crypto/openssh/channels.h | 4 +- crypto/openssh/config.h | 7 + crypto/openssh/configure.ac | 13 +- crypto/openssh/contrib/redhat/openssh.spec | 2 +- crypto/openssh/contrib/suse/openssh.spec | 2 +- crypto/openssh/m4/openssh.m4 | 3 + crypto/openssh/misc.c | 27 +- crypto/openssh/monitor.c | 11 +- crypto/openssh/myproposal.h | 4 +- crypto/openssh/openbsd-compat/arc4random.c | 2 +- crypto/openssh/openbsd-compat/bsd-misc.c | 10 +- crypto/openssh/openbsd-compat/bsd-misc.h | 2 +- crypto/openssh/openbsd-compat/bsd-poll.c | 6 +- crypto/openssh/openbsd-compat/chacha_private.h | 6 +- crypto/openssh/openbsd-compat/getrrsetbyname.c | 31 +- crypto/openssh/openbsd-compat/openbsd-compat.h | 8 + crypto/openssh/platform.c | 51 ++ crypto/openssh/platform.h | 1 + crypto/openssh/scp.c | 4 +- crypto/openssh/servconf.c | 9 +- crypto/openssh/servconf.h | 4 +- crypto/openssh/sftp-client.c | 122 ++- crypto/openssh/sftp-client.h | 5 +- crypto/openssh/sftp-glob.c | 8 +- crypto/openssh/sftp-server.c | 94 +- crypto/openssh/sftp.1 | 20 +- crypto/openssh/sftp.c | 17 +- crypto/openssh/ssh-agent.1 | 8 +- crypto/openssh/ssh-keygen.c | 9 +- crypto/openssh/ssh-keysign.8 | 6 +- crypto/openssh/ssh.1 | 10 +- crypto/openssh/ssh.c | 4 +- crypto/openssh/ssh_config | 2 +- crypto/openssh/ssh_config.5 | 10 +- crypto/openssh/sshd.8 | 6 +- crypto/openssh/sshd.c | 4 +- crypto/openssh/sshd_config | 2 +- crypto/openssh/sshd_config.5 | 8 +- crypto/openssh/sshsig.c | 9 +- crypto/openssh/version.h | 2 +- crypto/openssh/xmalloc.c | 5 +- 53 files changed, 1166 insertions(+), 870 deletions(-) diff --cc crypto/openssh/auth.c index faa1a4d3c666,000000000000..ad5a14e05ae8 mode 100644,000000..100644 --- a/crypto/openssh/auth.c +++ b/crypto/openssh/auth.c @@@ -1,1075 -1,0 +1,1031 @@@ +/* $OpenBSD: auth.c,v 1.154 2022/02/23 11:17:10 djm Exp $ */ +/* + * Copyright (c) 2000 Markus Friedl. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include "includes.h" +__RCSID("$FreeBSD$"); + +#include <sys/types.h> +#include <sys/stat.h> +#include <sys/socket.h> +#include <sys/wait.h> + +#include <netinet/in.h> + +#include <stdlib.h> +#include <errno.h> +#include <fcntl.h> +#ifdef HAVE_PATHS_H +# include <paths.h> +#endif +#include <pwd.h> +#ifdef HAVE_LOGIN_H +#include <login.h> +#endif +#ifdef USE_SHADOW +#include <shadow.h> +#endif +#include <stdarg.h> +#include <stdio.h> +#include <string.h> +#include <unistd.h> +#include <limits.h> +#include <netdb.h> +#include <time.h> + +#include "xmalloc.h" +#include "match.h" +#include "groupaccess.h" +#include "log.h" +#include "sshbuf.h" +#include "misc.h" +#include "servconf.h" +#include "sshkey.h" +#include "hostfile.h" +#include "auth.h" +#include "auth-options.h" +#include "canohost.h" +#include "uidswap.h" +#include "packet.h" +#include "loginrec.h" +#ifdef GSSAPI +#include "ssh-gss.h" +#endif +#include "authfile.h" +#include "monitor_wrap.h" +#include "ssherr.h" +#include "compat.h" +#include "channels.h" +#include "blacklist_client.h" + +/* import */ +extern ServerOptions options; +extern struct include_list includes; +extern int use_privsep; +extern struct sshbuf *loginmsg; +extern struct passwd *privsep_pw; +extern struct sshauthopt *auth_opts; + +/* Debugging messages */ +static struct sshbuf *auth_debug; + +/* + * Check if the user is allowed to log in via ssh. If user is listed + * in DenyUsers or one of user's groups is listed in DenyGroups, false + * will be returned. If AllowUsers isn't empty and user isn't listed + * there, or if AllowGroups isn't empty and one of user's groups isn't + * listed there, false will be returned. + * If the user's shell is not executable, false will be returned. + * Otherwise true is returned. + */ +int +allowed_user(struct ssh *ssh, struct passwd * pw) +{ + struct stat st; - const char *hostname = NULL, *ipaddr = NULL, *passwd = NULL; ++ const char *hostname = NULL, *ipaddr = NULL; + u_int i; + int r; - #ifdef USE_SHADOW - struct spwd *spw = NULL; - #endif + + /* Shouldn't be called if pw is NULL, but better safe than sorry... */ + if (!pw || !pw->pw_name) + return 0; + - #ifdef USE_SHADOW - if (!options.use_pam) - spw = getspnam(pw->pw_name); - #ifdef HAS_SHADOW_EXPIRE - if (!options.use_pam && spw != NULL && auth_shadow_acctexpired(spw)) ++ if (!options.use_pam && platform_locked_account(pw)) { ++ logit("User %.100s not allowed because account is locked", ++ pw->pw_name); + return 0; - #endif /* HAS_SHADOW_EXPIRE */ - #endif /* USE_SHADOW */ - - /* grab passwd field for locked account check */ - passwd = pw->pw_passwd; - #ifdef USE_SHADOW - if (spw != NULL) - #ifdef USE_LIBIAF - passwd = get_iaf_password(pw); - #else - passwd = spw->sp_pwdp; - #endif /* USE_LIBIAF */ - #endif - - /* check for locked account */ - if (!options.use_pam && passwd && *passwd) { - int locked = 0; - - #ifdef LOCKED_PASSWD_STRING - if (strcmp(passwd, LOCKED_PASSWD_STRING) == 0) - locked = 1; - #endif - #ifdef LOCKED_PASSWD_PREFIX - if (strncmp(passwd, LOCKED_PASSWD_PREFIX, - strlen(LOCKED_PASSWD_PREFIX)) == 0) - locked = 1; - #endif - #ifdef LOCKED_PASSWD_SUBSTR - if (strstr(passwd, LOCKED_PASSWD_SUBSTR)) - locked = 1; - #endif - #ifdef USE_LIBIAF - free((void *) passwd); - #endif /* USE_LIBIAF */ - if (locked) { - logit("User %.100s not allowed because account is locked", - pw->pw_name); - return 0; - } + } + + /* + * Deny if shell does not exist or is not executable unless we + * are chrooting. + */ + if (options.chroot_directory == NULL || + strcasecmp(options.chroot_directory, "none") == 0) { + char *shell = xstrdup((pw->pw_shell[0] == '\0') ? + _PATH_BSHELL : pw->pw_shell); /* empty = /bin/sh */ + + if (stat(shell, &st) == -1) { + logit("User %.100s not allowed because shell %.100s " + "does not exist", pw->pw_name, shell); + free(shell); + return 0; + } + if (S_ISREG(st.st_mode) == 0 || + (st.st_mode & (S_IXOTH|S_IXUSR|S_IXGRP)) == 0) { + logit("User %.100s not allowed because shell %.100s " + "is not executable", pw->pw_name, shell); + free(shell); + return 0; + } + free(shell); + } + + if (options.num_deny_users > 0 || options.num_allow_users > 0 || + options.num_deny_groups > 0 || options.num_allow_groups > 0) { + hostname = auth_get_canonical_hostname(ssh, options.use_dns); + ipaddr = ssh_remote_ipaddr(ssh); + } + + /* Return false if user is listed in DenyUsers */ + if (options.num_deny_users > 0) { + for (i = 0; i < options.num_deny_users; i++) { + r = match_user(pw->pw_name, hostname, ipaddr, + options.deny_users[i]); + if (r < 0) { + fatal("Invalid DenyUsers pattern \"%.100s\"", + options.deny_users[i]); + } else if (r != 0) { + logit("User %.100s from %.100s not allowed " + "because listed in DenyUsers", + pw->pw_name, hostname); + return 0; + } + } + } + /* Return false if AllowUsers isn't empty and user isn't listed there */ + if (options.num_allow_users > 0) { + for (i = 0; i < options.num_allow_users; i++) { + r = match_user(pw->pw_name, hostname, ipaddr, + options.allow_users[i]); + if (r < 0) { + fatal("Invalid AllowUsers pattern \"%.100s\"", + options.allow_users[i]); + } else if (r == 1) + break; + } + /* i < options.num_allow_users iff we break for loop */ + if (i >= options.num_allow_users) { + logit("User %.100s from %.100s not allowed because " + "not listed in AllowUsers", pw->pw_name, hostname); + return 0; + } + } + if (options.num_deny_groups > 0 || options.num_allow_groups > 0) { + /* Get the user's group access list (primary and supplementary) */ + if (ga_init(pw->pw_name, pw->pw_gid) == 0) { + logit("User %.100s from %.100s not allowed because " + "not in any group", pw->pw_name, hostname); + return 0; + } + + /* Return false if one of user's groups is listed in DenyGroups */ + if (options.num_deny_groups > 0) + if (ga_match(options.deny_groups, + options.num_deny_groups)) { + ga_free(); + logit("User %.100s from %.100s not allowed " + "because a group is listed in DenyGroups", + pw->pw_name, hostname); + return 0; + } + /* + * Return false if AllowGroups isn't empty and one of user's groups + * isn't listed there + */ + if (options.num_allow_groups > 0) + if (!ga_match(options.allow_groups, + options.num_allow_groups)) { + ga_free(); + logit("User %.100s from %.100s not allowed " + "because none of user's groups are listed " + "in AllowGroups", pw->pw_name, hostname); + return 0; + } + ga_free(); + } + +#ifdef CUSTOM_SYS_AUTH_ALLOWED_USER + if (!sys_auth_allowed_user(pw, loginmsg)) + return 0; +#endif + + /* We found no reason not to let this user try to log on... */ + return 1; +} + +/* + * Formats any key left in authctxt->auth_method_key for inclusion in + * auth_log()'s message. Also includes authxtct->auth_method_info if present. + */ +static char * +format_method_key(Authctxt *authctxt) +{ + const struct sshkey *key = authctxt->auth_method_key; + const char *methinfo = authctxt->auth_method_info; + char *fp, *cafp, *ret = NULL; + + if (key == NULL) + return NULL; + + if (sshkey_is_cert(key)) { + fp = sshkey_fingerprint(key, + options.fingerprint_hash, SSH_FP_DEFAULT); + cafp = sshkey_fingerprint(key->cert->signature_key, + options.fingerprint_hash, SSH_FP_DEFAULT); + xasprintf(&ret, "%s %s ID %s (serial %llu) CA %s %s%s%s", + sshkey_type(key), fp == NULL ? "(null)" : fp, + key->cert->key_id, + (unsigned long long)key->cert->serial, + sshkey_type(key->cert->signature_key), + cafp == NULL ? "(null)" : cafp, + methinfo == NULL ? "" : ", ", + methinfo == NULL ? "" : methinfo); + free(fp); + free(cafp); + } else { + fp = sshkey_fingerprint(key, options.fingerprint_hash, + SSH_FP_DEFAULT); + xasprintf(&ret, "%s %s%s%s", sshkey_type(key), + fp == NULL ? "(null)" : fp, + methinfo == NULL ? "" : ", ", + methinfo == NULL ? "" : methinfo); + free(fp); + } + return ret; +} + +void +auth_log(struct ssh *ssh, int authenticated, int partial, + const char *method, const char *submethod) +{ + Authctxt *authctxt = (Authctxt *)ssh->authctxt; + int level = SYSLOG_LEVEL_VERBOSE; + const char *authmsg; + char *extra = NULL; + + if (use_privsep && !mm_is_monitor() && !authctxt->postponed) + return; + + /* Raise logging level */ + if (authenticated == 1 || + !authctxt->valid || + authctxt->failures >= options.max_authtries / 2 || + strcmp(method, "password") == 0) + level = SYSLOG_LEVEL_INFO; + + if (authctxt->postponed) + authmsg = "Postponed"; + else if (partial) + authmsg = "Partial"; + else { + authmsg = authenticated ? "Accepted" : "Failed"; + if (authenticated) + BLACKLIST_NOTIFY(ssh, BLACKLIST_AUTH_OK, "ssh"); + } + + if ((extra = format_method_key(authctxt)) == NULL) { + if (authctxt->auth_method_info != NULL) + extra = xstrdup(authctxt->auth_method_info); + } + + do_log2(level, "%s %s%s%s for %s%.100s from %.200s port %d ssh2%s%s", + authmsg, + method, + submethod != NULL ? "/" : "", submethod == NULL ? "" : submethod, + authctxt->valid ? "" : "invalid user ", + authctxt->user, + ssh_remote_ipaddr(ssh), + ssh_remote_port(ssh), + extra != NULL ? ": " : "", + extra != NULL ? extra : ""); + + free(extra); + +#if defined(CUSTOM_FAILED_LOGIN) || defined(SSH_AUDIT_EVENTS) + if (authenticated == 0 && !(authctxt->postponed || partial)) { + /* Log failed login attempt */ +# ifdef CUSTOM_FAILED_LOGIN + if (strcmp(method, "password") == 0 || + strncmp(method, "keyboard-interactive", 20) == 0 || + strcmp(method, "challenge-response") == 0) + record_failed_login(ssh, authctxt->user, + auth_get_canonical_hostname(ssh, options.use_dns), "ssh"); +# endif +# ifdef SSH_AUDIT_EVENTS + audit_event(ssh, audit_classify_auth(method)); +# endif + } +#endif +#if defined(CUSTOM_FAILED_LOGIN) && defined(WITH_AIXAUTHENTICATE) + if (authenticated) + sys_auth_record_login(authctxt->user, + auth_get_canonical_hostname(ssh, options.use_dns), "ssh", + loginmsg); +#endif +} + +void +auth_maxtries_exceeded(struct ssh *ssh) +{ + Authctxt *authctxt = (Authctxt *)ssh->authctxt; + + error("maximum authentication attempts exceeded for " + "%s%.100s from %.200s port %d ssh2", + authctxt->valid ? "" : "invalid user ", + authctxt->user, + ssh_remote_ipaddr(ssh), + ssh_remote_port(ssh)); + ssh_packet_disconnect(ssh, "Too many authentication failures"); + /* NOTREACHED */ +} + +/* + * Check whether root logins are disallowed. + */ +int +auth_root_allowed(struct ssh *ssh, const char *method) +{ + switch (options.permit_root_login) { + case PERMIT_YES: + return 1; + case PERMIT_NO_PASSWD: + if (strcmp(method, "publickey") == 0 || + strcmp(method, "hostbased") == 0 || + strcmp(method, "gssapi-with-mic") == 0) + return 1; + break; + case PERMIT_FORCED_ONLY: + if (auth_opts->force_command != NULL) { + logit("Root login accepted for forced command."); + return 1; + } + break; + } + logit("ROOT LOGIN REFUSED FROM %.200s port %d", + ssh_remote_ipaddr(ssh), ssh_remote_port(ssh)); + return 0; +} + + +/* + * Given a template and a passwd structure, build a filename + * by substituting % tokenised options. Currently, %% becomes '%', + * %h becomes the home directory and %u the username. + * + * This returns a buffer allocated by xmalloc. + */ +char * +expand_authorized_keys(const char *filename, struct passwd *pw) +{ + char *file, uidstr[32], ret[PATH_MAX]; + int i; + + snprintf(uidstr, sizeof(uidstr), "%llu", + (unsigned long long)pw->pw_uid); + file = percent_expand(filename, "h", pw->pw_dir, + "u", pw->pw_name, "U", uidstr, (char *)NULL); + + /* + * Ensure that filename starts anchored. If not, be backward + * compatible and prepend the '%h/' + */ + if (path_absolute(file)) + return (file); + + i = snprintf(ret, sizeof(ret), "%s/%s", pw->pw_dir, file); + if (i < 0 || (size_t)i >= sizeof(ret)) + fatal("expand_authorized_keys: path too long"); + free(file); + return (xstrdup(ret)); +} + +char * +authorized_principals_file(struct passwd *pw) +{ + if (options.authorized_principals_file == NULL) + return NULL; + return expand_authorized_keys(options.authorized_principals_file, pw); +} + +/* return ok if key exists in sysfile or userfile */ +HostStatus +check_key_in_hostfiles(struct passwd *pw, struct sshkey *key, const char *host, + const char *sysfile, const char *userfile) +{ + char *user_hostfile; + struct stat st; + HostStatus host_status; + struct hostkeys *hostkeys; + const struct hostkey_entry *found; + + hostkeys = init_hostkeys(); + load_hostkeys(hostkeys, host, sysfile, 0); + if (userfile != NULL) { + user_hostfile = tilde_expand_filename(userfile, pw->pw_uid); + if (options.strict_modes && + (stat(user_hostfile, &st) == 0) && + ((st.st_uid != 0 && st.st_uid != pw->pw_uid) || + (st.st_mode & 022) != 0)) { + logit("Authentication refused for %.100s: " + "bad owner or modes for %.200s", + pw->pw_name, user_hostfile); + auth_debug_add("Ignored %.200s: bad ownership or modes", + user_hostfile); + } else { + temporarily_use_uid(pw); + load_hostkeys(hostkeys, host, user_hostfile, 0); + restore_uid(); + } + free(user_hostfile); + } + host_status = check_key_in_hostkeys(hostkeys, key, &found); + if (host_status == HOST_REVOKED) + error("WARNING: revoked key for %s attempted authentication", + host); + else if (host_status == HOST_OK) + debug_f("key for %s found at %s:%ld", + found->host, found->file, found->line); + else + debug_f("key for host %s not found", host); + + free_hostkeys(hostkeys); + + return host_status; +} + +static FILE * +auth_openfile(const char *file, struct passwd *pw, int strict_modes, + int log_missing, char *file_type) +{ + char line[1024]; + struct stat st; + int fd; + FILE *f; + + if ((fd = open(file, O_RDONLY|O_NONBLOCK)) == -1) { + if (log_missing || errno != ENOENT) + debug("Could not open %s '%s': %s", file_type, file, + strerror(errno)); + return NULL; + } + + if (fstat(fd, &st) == -1) { + close(fd); + return NULL; + } + if (!S_ISREG(st.st_mode)) { + logit("User %s %s %s is not a regular file", + pw->pw_name, file_type, file); + close(fd); + return NULL; + } + unset_nonblock(fd); + if ((f = fdopen(fd, "r")) == NULL) { + close(fd); + return NULL; + } + if (strict_modes && + safe_path_fd(fileno(f), file, pw, line, sizeof(line)) != 0) { + fclose(f); + logit("Authentication refused: %s", line); + auth_debug_add("Ignored %s: %s", file_type, line); + return NULL; + } + + return f; +} + + +FILE * +auth_openkeyfile(const char *file, struct passwd *pw, int strict_modes) +{ + return auth_openfile(file, pw, strict_modes, 1, "authorized keys"); +} + +FILE * +auth_openprincipals(const char *file, struct passwd *pw, int strict_modes) +{ + return auth_openfile(file, pw, strict_modes, 0, + "authorized principals"); +} + +struct passwd * +getpwnamallow(struct ssh *ssh, const char *user) +{ +#ifdef HAVE_LOGIN_CAP + extern login_cap_t *lc; +#ifdef HAVE_AUTH_HOSTOK + const char *from_host, *from_ip; +#endif +#ifdef BSD_AUTH + auth_session_t *as; +#endif +#endif + struct passwd *pw; + struct connection_info *ci; + u_int i; + + ci = get_connection_info(ssh, 1, options.use_dns); + ci->user = user; + parse_server_match_config(&options, &includes, ci); + log_change_level(options.log_level); + log_verbose_reset(); + for (i = 0; i < options.num_log_verbose; i++) + log_verbose_add(options.log_verbose[i]); + process_permitopen(ssh, &options); + +#if defined(_AIX) && defined(HAVE_SETAUTHDB) + aix_setauthdb(user); +#endif + + pw = getpwnam(user); + +#if defined(_AIX) && defined(HAVE_SETAUTHDB) + aix_restoreauthdb(); +#endif + if (pw == NULL) { + BLACKLIST_NOTIFY(ssh, BLACKLIST_BAD_USER, user); + logit("Invalid user %.100s from %.100s port %d", + user, ssh_remote_ipaddr(ssh), ssh_remote_port(ssh)); +#ifdef CUSTOM_FAILED_LOGIN + record_failed_login(ssh, user, + auth_get_canonical_hostname(ssh, options.use_dns), "ssh"); +#endif +#ifdef SSH_AUDIT_EVENTS + audit_event(ssh, SSH_INVALID_USER); +#endif /* SSH_AUDIT_EVENTS */ + return (NULL); + } + if (!allowed_user(ssh, pw)) + return (NULL); +#ifdef HAVE_LOGIN_CAP + if ((lc = login_getpwclass(pw)) == NULL) { + debug("unable to get login class: %s", user); + return (NULL); + } +#ifdef HAVE_AUTH_HOSTOK + from_host = auth_get_canonical_hostname(ssh, options.use_dns); + from_ip = ssh_remote_ipaddr(ssh); + if (!auth_hostok(lc, from_host, from_ip)) { + debug("Denied connection for %.200s from %.200s [%.200s].", + pw->pw_name, from_host, from_ip); + return (NULL); + } +#endif /* HAVE_AUTH_HOSTOK */ +#ifdef HAVE_AUTH_TIMEOK + if (!auth_timeok(lc, time(NULL))) { + debug("LOGIN %.200s REFUSED (TIME)", pw->pw_name); + return (NULL); + } +#endif /* HAVE_AUTH_TIMEOK */ +#ifdef BSD_AUTH + if ((as = auth_open()) == NULL || auth_setpwd(as, pw) != 0 || + auth_approval(as, lc, pw->pw_name, "ssh") <= 0) { + debug("Approval failure for %s", user); + pw = NULL; + } + if (as != NULL) + auth_close(as); +#endif +#endif + if (pw != NULL) + return (pwcopy(pw)); + return (NULL); +} + +/* Returns 1 if key is revoked by revoked_keys_file, 0 otherwise */ +int +auth_key_is_revoked(struct sshkey *key) +{ + char *fp = NULL; + int r; + + if (options.revoked_keys_file == NULL) + return 0; + if ((fp = sshkey_fingerprint(key, options.fingerprint_hash, + SSH_FP_DEFAULT)) == NULL) { + r = SSH_ERR_ALLOC_FAIL; + error_fr(r, "fingerprint key"); + goto out; + } + + r = sshkey_check_revoked(key, options.revoked_keys_file); + switch (r) { + case 0: + break; /* not revoked */ + case SSH_ERR_KEY_REVOKED: + error("Authentication key %s %s revoked by file %s", + sshkey_type(key), fp, options.revoked_keys_file); + goto out; + default: + error_r(r, "Error checking authentication key %s %s in " + "revoked keys file %s", sshkey_type(key), fp, + options.revoked_keys_file); + goto out; + } + + /* Success */ + r = 0; + + out: + free(fp); + return r == 0 ? 0 : 1; +} + +void +auth_debug_add(const char *fmt,...) +{ + char buf[1024]; + va_list args; + int r; + + if (auth_debug == NULL) + return; + + va_start(args, fmt); + vsnprintf(buf, sizeof(buf), fmt, args); + va_end(args); + if ((r = sshbuf_put_cstring(auth_debug, buf)) != 0) + fatal_fr(r, "sshbuf_put_cstring"); +} + +void +auth_debug_send(struct ssh *ssh) +{ + char *msg; + int r; + + if (auth_debug == NULL) + return; + while (sshbuf_len(auth_debug) != 0) { + if ((r = sshbuf_get_cstring(auth_debug, &msg, NULL)) != 0) + fatal_fr(r, "sshbuf_get_cstring"); + ssh_packet_send_debug(ssh, "%s", msg); + free(msg); + } +} + +void +auth_debug_reset(void) +{ + if (auth_debug != NULL) + sshbuf_reset(auth_debug); + else if ((auth_debug = sshbuf_new()) == NULL) + fatal_f("sshbuf_new failed"); +} + +struct passwd * +fakepw(void) +{ + static int done = 0; + static struct passwd fake; + const char hashchars[] = "./ABCDEFGHIJKLMNOPQRSTUVWXYZ" + "abcdefghijklmnopqrstuvwxyz0123456789"; /* from bcrypt.c */ + char *cp; + + if (done) + return (&fake); + + memset(&fake, 0, sizeof(fake)); + fake.pw_name = "NOUSER"; + fake.pw_passwd = xstrdup("$2a$10$" + "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"); + for (cp = fake.pw_passwd + 7; *cp != '\0'; cp++) + *cp = hashchars[arc4random_uniform(sizeof(hashchars) - 1)]; +#ifdef HAVE_STRUCT_PASSWD_PW_GECOS + fake.pw_gecos = "NOUSER"; +#endif + fake.pw_uid = privsep_pw == NULL ? (uid_t)-1 : privsep_pw->pw_uid; + fake.pw_gid = privsep_pw == NULL ? (gid_t)-1 : privsep_pw->pw_gid; +#ifdef HAVE_STRUCT_PASSWD_PW_CLASS + fake.pw_class = ""; +#endif + fake.pw_dir = "/nonexist"; + fake.pw_shell = "/nonexist"; + done = 1; + + return (&fake); +} + +/* + * Returns the remote DNS hostname as a string. The returned string must not + * be freed. NB. this will usually trigger a DNS query the first time it is + * called. + * This function does additional checks on the hostname to mitigate some + * attacks on based on conflation of hostnames and IP addresses. + */ + +static char * +remote_hostname(struct ssh *ssh) +{ + struct sockaddr_storage from; + socklen_t fromlen; + struct addrinfo hints, *ai, *aitop; + char name[NI_MAXHOST], ntop2[NI_MAXHOST]; + const char *ntop = ssh_remote_ipaddr(ssh); + + /* Get IP address of client. */ + fromlen = sizeof(from); + memset(&from, 0, sizeof(from)); + if (getpeername(ssh_packet_get_connection_in(ssh), + (struct sockaddr *)&from, &fromlen) == -1) { + debug("getpeername failed: %.100s", strerror(errno)); + return xstrdup(ntop); + } + + ipv64_normalise_mapped(&from, &fromlen); + if (from.ss_family == AF_INET6) + fromlen = sizeof(struct sockaddr_in6); + + debug3("Trying to reverse map address %.100s.", ntop); + /* Map the IP address to a host name. */ + if (getnameinfo((struct sockaddr *)&from, fromlen, name, sizeof(name), + NULL, 0, NI_NAMEREQD) != 0) { + /* Host name not found. Use ip address. */ + return xstrdup(ntop); + } + + /* + * if reverse lookup result looks like a numeric hostname, + * someone is trying to trick us by PTR record like following: + * 1.1.1.10.in-addr.arpa. IN PTR 2.3.4.5 + */ + memset(&hints, 0, sizeof(hints)); + hints.ai_socktype = SOCK_DGRAM; /*dummy*/ + hints.ai_flags = AI_NUMERICHOST; + if (getaddrinfo(name, NULL, &hints, &ai) == 0) { + logit("Nasty PTR record \"%s\" is set up for %s, ignoring", + name, ntop); + freeaddrinfo(ai); + return xstrdup(ntop); + } + + /* Names are stored in lowercase. */ + lowercase(name); + + /* + * Map it back to an IP address and check that the given + * address actually is an address of this host. This is + * necessary because anyone with access to a name server can + * define arbitrary names for an IP address. Mapping from + * name to IP address can be trusted better (but can still be + * fooled if the intruder has access to the name server of + * the domain). + */ + memset(&hints, 0, sizeof(hints)); + hints.ai_family = from.ss_family; + hints.ai_socktype = SOCK_STREAM; + if (getaddrinfo(name, NULL, &hints, &aitop) != 0) { + logit("reverse mapping checking getaddrinfo for %.700s " + "[%s] failed.", name, ntop); + return xstrdup(ntop); + } + /* Look for the address from the list of addresses. */ + for (ai = aitop; ai; ai = ai->ai_next) { + if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop2, + sizeof(ntop2), NULL, 0, NI_NUMERICHOST) == 0 && + (strcmp(ntop, ntop2) == 0)) + break; + } + freeaddrinfo(aitop); + /* If we reached the end of the list, the address was not there. */ + if (ai == NULL) { + /* Address not found for the host name. */ + logit("Address %.100s maps to %.600s, but this does not " + "map back to the address.", ntop, name); + return xstrdup(ntop); + } + return xstrdup(name); +} + +/* + * Return the canonical name of the host in the other side of the current + * connection. The host name is cached, so it is efficient to call this + * several times. + */ + +const char * +auth_get_canonical_hostname(struct ssh *ssh, int use_dns) +{ + static char *dnsname; + + if (!use_dns) + return ssh_remote_ipaddr(ssh); + else if (dnsname != NULL) + return dnsname; + else { + dnsname = remote_hostname(ssh); + return dnsname; + } +} + +/* These functions link key/cert options to the auth framework */ + +/* Log sshauthopt options locally and (optionally) for remote transmission */ +void +auth_log_authopts(const char *loc, const struct sshauthopt *opts, int do_remote) *** 8354 LINES SKIPPED ***
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