The branch main has been updated by emaste: URL: https://cgit.FreeBSD.org/src/commit/?id=4d3fc8b0570b29fb0d6ee9525f104d52176ff0d4
commit 4d3fc8b0570b29fb0d6ee9525f104d52176ff0d4 Merge: 7d0b91591966 36b354d74be5 Author: Ed Maste <[email protected]> AuthorDate: 2023-03-16 14:29:55 +0000 Commit: Ed Maste <[email protected]> CommitDate: 2023-03-16 14:29:55 +0000 ssh: Update to OpenSSH 9.3p1 This release fixes a number of security bugs and has minor new features and bug fixes. Security fixes, from the release notes (https://www.openssh.com/txt/release-9.3): This release contains fixes for a security problem and a memory safety problem. The memory safety problem is not believed to be exploitable, but we report most network-reachable memory faults as security bugs. * ssh-add(1): when adding smartcard keys to ssh-agent(1) with the per-hop destination constraints (ssh-add -h ...) added in OpenSSH 8.9, a logic error prevented the constraints from being communicated to the agent. This resulted in the keys being added without constraints. The common cases of non-smartcard keys and keys without destination constraints are unaffected. This problem was reported by Luci Stanescu. * ssh(1): Portable OpenSSH provides an implementation of the getrrsetbyname(3) function if the standard library does not provide it, for use by the VerifyHostKeyDNS feature. A specifically crafted DNS response could cause this function to perform an out-of-bounds read of adjacent stack data, but this condition does not appear to be exploitable beyond denial-of- service to the ssh(1) client. The getrrsetbyname(3) replacement is only included if the system's standard library lacks this function and portable OpenSSH was not compiled with the ldns library (--with-ldns). getrrsetbyname(3) is only invoked if using VerifyHostKeyDNS to fetch SSHFP records. This problem was found by the Coverity static analyzer. Sponsored by: The FreeBSD Foundation crypto/openssh/.depend | 51 +- crypto/openssh/.github/ci-status.md | 7 +- crypto/openssh/.github/configs | 2 +- crypto/openssh/.github/run_test.sh | 2 +- crypto/openssh/.github/setup_ci.sh | 6 +- crypto/openssh/.github/workflows/c-cpp.yml | 1 + crypto/openssh/.github/workflows/selfhosted.yml | 3 + crypto/openssh/.github/workflows/upstream.yml | 1 + crypto/openssh/ChangeLog | 15098 ++++++++++--------- crypto/openssh/Makefile.in | 5 + crypto/openssh/README | 3 +- crypto/openssh/README.md | 1 + crypto/openssh/auth-pam.c | 15 +- crypto/openssh/auth-shadow.c | 14 +- crypto/openssh/auth.c | 3 +- crypto/openssh/auth2-hostbased.c | 9 +- crypto/openssh/auth2-none.c | 3 +- crypto/openssh/auth2-pubkey.c | 8 +- crypto/openssh/auth2-pubkeyfile.c | 3 +- crypto/openssh/auth2.c | 5 +- crypto/openssh/authfd.c | 9 +- crypto/openssh/authfile.c | 4 +- crypto/openssh/canohost.c | 5 +- crypto/openssh/channels.c | 42 +- crypto/openssh/channels.h | 4 +- crypto/openssh/clientloop.c | 14 +- crypto/openssh/compat.c | 53 +- crypto/openssh/compat.h | 14 +- crypto/openssh/contrib/redhat/openssh.spec | 2 +- crypto/openssh/contrib/suse/openssh.spec | 2 +- crypto/openssh/dispatch.c | 3 +- crypto/openssh/dns.c | 8 +- crypto/openssh/dns.h | 4 +- crypto/openssh/hostfile.c | 15 +- crypto/openssh/kex.c | 72 +- crypto/openssh/kex.h | 5 +- crypto/openssh/kexgexs.c | 3 +- crypto/openssh/krl.c | 3 +- crypto/openssh/misc.c | 5 +- crypto/openssh/misc.h | 5 +- crypto/openssh/moduli.c | 13 +- crypto/openssh/monitor.c | 11 +- crypto/openssh/mux.c | 4 +- crypto/openssh/openbsd-compat/bsd-getentropy.c | 2 +- crypto/openssh/openbsd-compat/bsd-snprintf.c | 90 +- crypto/openssh/openbsd-compat/getopt.h | 3 + crypto/openssh/openbsd-compat/getopt_long.c | 14 + crypto/openssh/openbsd-compat/getrrsetbyname.c | 47 +- .../openssh/openbsd-compat/libressl-api-compat.c | 14 +- crypto/openssh/openbsd-compat/mktemp.c | 23 + crypto/openssh/openbsd-compat/openbsd-compat.h | 3 + crypto/openssh/packet.c | 4 +- crypto/openssh/progressmeter.c | 95 +- crypto/openssh/readconf.c | 11 +- crypto/openssh/regress/Makefile | 6 +- crypto/openssh/regress/agent-getpeereid.sh | 3 +- crypto/openssh/regress/agent-restrict.sh | 6 +- crypto/openssh/regress/agent.sh | 4 +- crypto/openssh/regress/dhgex.sh | 6 +- crypto/openssh/regress/integrity.sh | 4 +- crypto/openssh/regress/keygen-sshfp.sh | 22 +- crypto/openssh/regress/knownhosts.sh | 20 +- crypto/openssh/regress/multiplex.sh | 4 +- crypto/openssh/regress/sshd-log-wrapper.sh | 12 - crypto/openssh/regress/test-exec.sh | 88 +- crypto/openssh/regress/timestamp.c | 46 + .../openssh/regress/unittests/kex/test_proposal.c | 47 +- crypto/openssh/regress/unittests/kex/tests.c | 8 +- .../openssh/regress/unittests/misc/test_ptimeout.c | 6 +- crypto/openssh/sandbox-seccomp-filter.c | 93 +- crypto/openssh/scp.c | 8 +- crypto/openssh/servconf.c | 15 +- crypto/openssh/serverloop.c | 5 +- crypto/openssh/session.c | 4 +- crypto/openssh/sftp-client.c | 3 +- crypto/openssh/sftp-server.c | 4 +- crypto/openssh/sftp.c | 14 +- crypto/openssh/ssh-add.c | 9 +- crypto/openssh/ssh-agent.c | 8 +- crypto/openssh/ssh-dss.c | 3 +- crypto/openssh/ssh-ecdsa-sk.c | 3 +- crypto/openssh/ssh-ecdsa.c | 4 +- crypto/openssh/ssh-keygen.1 | 19 +- crypto/openssh/ssh-keygen.c | 42 +- crypto/openssh/ssh-keyscan.1 | 19 +- crypto/openssh/ssh-keyscan.c | 22 +- crypto/openssh/ssh-pkcs11.c | 8 +- crypto/openssh/ssh-rsa.c | 3 +- crypto/openssh/ssh.c | 3 +- crypto/openssh/ssh_config.5 | 6 +- crypto/openssh/ssh_namespace.h | 4 +- crypto/openssh/sshconnect.c | 5 +- crypto/openssh/sshconnect2.c | 81 +- crypto/openssh/sshd.8 | 20 +- crypto/openssh/sshd.c | 92 +- crypto/openssh/sshd_config | 2 +- crypto/openssh/sshd_config.5 | 20 +- crypto/openssh/umac.c | 5 +- crypto/openssh/version.h | 6 +- secure/lib/libssh/Makefile | 1 + 100 files changed, 8556 insertions(+), 8103 deletions(-) diff --cc crypto/openssh/README.md index 3da933817989,000000000000..9431b0ffdd89 mode 100644,000000..100644 --- a/crypto/openssh/README.md +++ b/crypto/openssh/README.md @@@ -1,85 -1,0 +1,86 @@@ +# Portable OpenSSH + +[](https://github.com/openssh/openssh-portable/actions/workflows/c-cpp.yml) +[](https://bugs.chromium.org/p/oss-fuzz/issues/list?sort=-opened&can=1&q=proj:openssh) ++[](https://scan.coverity.com/projects/openssh-portable) + +OpenSSH is a complete implementation of the SSH protocol (version 2) for secure remote login, command execution and file transfer. It includes a client ``ssh`` and server ``sshd``, file transfer utilities ``scp`` and ``sftp`` as well as tools for key generation (``ssh-keygen``), run-time key storage (``ssh-agent``) and a number of supporting programs. + +This is a port of OpenBSD's [OpenSSH](https://openssh.com) to most Unix-like operating systems, including Linux, OS X and Cygwin. Portable OpenSSH polyfills OpenBSD APIs that are not available elsewhere, adds sshd sandboxing for more operating systems and includes support for OS-native authentication and auditing (e.g. using PAM). + +## Documentation + +The official documentation for OpenSSH are the man pages for each tool: + +* [ssh(1)](https://man.openbsd.org/ssh.1) +* [sshd(8)](https://man.openbsd.org/sshd.8) +* [ssh-keygen(1)](https://man.openbsd.org/ssh-keygen.1) +* [ssh-agent(1)](https://man.openbsd.org/ssh-agent.1) +* [scp(1)](https://man.openbsd.org/scp.1) +* [sftp(1)](https://man.openbsd.org/sftp.1) +* [ssh-keyscan(8)](https://man.openbsd.org/ssh-keyscan.8) +* [sftp-server(8)](https://man.openbsd.org/sftp-server.8) + +## Stable Releases + +Stable release tarballs are available from a number of [download mirrors](https://www.openssh.com/portable.html#downloads). We recommend the use of a stable release for most users. Please read the [release notes](https://www.openssh.com/releasenotes.html) for details of recent changes and potential incompatibilities. + +## Building Portable OpenSSH + +### Dependencies + +Portable OpenSSH is built using autoconf and make. It requires a working C compiler, standard library and headers. + +``libcrypto`` from either [LibreSSL](https://www.libressl.org/) or [OpenSSL](https://www.openssl.org) may also be used. OpenSSH may be built without either of these, but the resulting binaries will have only a subset of the cryptographic algorithms normally available. + +[zlib](https://www.zlib.net/) is optional; without it transport compression is not supported. + +FIDO security token support needs [libfido2](https://github.com/Yubico/libfido2) and its dependencies and will be enabled automatically if they are found. + +In addition, certain platforms and build-time options may require additional dependencies; see README.platform for details about your platform. + +### Building a release + +Releases include a pre-built copy of the ``configure`` script and may be built using: + +``` +tar zxvf openssh-X.YpZ.tar.gz +cd openssh +./configure # [options] +make && make tests +``` + +See the [Build-time Customisation](#build-time-customisation) section below for configure options. If you plan on installing OpenSSH to your system, then you will usually want to specify destination paths. + +### Building from git + +If building from git, you'll need [autoconf](https://www.gnu.org/software/autoconf/) installed to build the ``configure`` script. The following commands will check out and build portable OpenSSH from git: + +``` +git clone https://github.com/openssh/openssh-portable # or https://anongit.mindrot.org/openssh.git +cd openssh-portable +autoreconf +./configure +make && make tests +``` + +### Build-time Customisation + +There are many build-time customisation options available. All Autoconf destination path flags (e.g. ``--prefix``) are supported (and are usually required if you want to install OpenSSH). + +For a full list of available flags, run ``./configure --help`` but a few of the more frequently-used ones are described below. Some of these flags will require additional libraries and/or headers be installed. + +Flag | Meaning +--- | --- +``--with-pam`` | Enable [PAM](https://en.wikipedia.org/wiki/Pluggable_authentication_module) support. [OpenPAM](https://www.openpam.org/), [Linux PAM](http://www.linux-pam.org/) and Solaris PAM are supported. +``--with-libedit`` | Enable [libedit](https://www.thrysoee.dk/editline/) support for sftp. +``--with-kerberos5`` | Enable Kerberos/GSSAPI support. Both [Heimdal](https://www.h5l.org/) and [MIT](https://web.mit.edu/kerberos/) Kerberos implementations are supported. +``--with-selinux`` | Enable [SELinux](https://en.wikipedia.org/wiki/Security-Enhanced_Linux) support. + +## Development + +Portable OpenSSH development is discussed on the [openssh-unix-dev mailing list](https://lists.mindrot.org/mailman/listinfo/openssh-unix-dev) ([archive mirror](https://marc.info/?l=openssh-unix-dev)). Bugs and feature requests are tracked on our [Bugzilla](https://bugzilla.mindrot.org/). + +## Reporting bugs + +_Non-security_ bugs may be reported to the developers via [Bugzilla](https://bugzilla.mindrot.org/) or via the mailing list above. Security bugs should be reported to [[email protected]](mailto:openssh.openssh.com). diff --cc crypto/openssh/auth.c index 93610963f3b3,000000000000..f390df839d62 mode 100644,000000..100644 --- a/crypto/openssh/auth.c +++ b/crypto/openssh/auth.c @@@ -1,880 -1,0 +1,879 @@@ - /* $OpenBSD: auth.c,v 1.159 2022/12/09 00:17:40 dtucker Exp $ */ ++/* $OpenBSD: auth.c,v 1.160 2023/03/05 05:34:09 dtucker 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" + +#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; + u_int i; + int r; + + /* Shouldn't be called if pw is NULL, but better safe than sorry... */ + if (!pw || !pw->pw_name) + return 0; + + if (!options.use_pam && platform_locked_account(pw)) { + 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; +} + +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; + + va_start(args, fmt); + vsnprintf(buf, sizeof(buf), fmt, args); + va_end(args); + debug3("%s", buf); + if (auth_debug != NULL) + 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 && *** 7651 LINES SKIPPED ***
