git: 069ac18495ad - main - ssh: Update to OpenSSH 9.6p1
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Date: Fri, 05 Jan 2024 03:20:14 UTC
The branch main has been updated by emaste:
URL: https://cgit.FreeBSD.org/src/commit/?id=069ac18495ad8fde2748bc94b0f80a50250bb01d
commit 069ac18495ad8fde2748bc94b0f80a50250bb01d
Merge: 6c951b37170f 38f55691cb1b
Author: Ed Maste <emaste@FreeBSD.org>
AuthorDate: 2024-01-05 03:16:30 +0000
Commit: Ed Maste <emaste@FreeBSD.org>
CommitDate: 2024-01-05 03:16:30 +0000
ssh: Update to OpenSSH 9.6p1
From the release notes,
> This release contains a number of security fixes, some small features
> and bugfixes.
The most significant change in 9.6p1 is a set of fixes for a newly-
discovered weakness in the SSH transport protocol. The fix was already
merged into FreeBSD and released as FreeBSD-SA-23:19.openssh.
Full release notes at https://www.openssh.com/txt/release-9.6
Relnotes: Yes
Sponsored by: The FreeBSD Foundation
crypto/openssh/.depend | 3 +-
crypto/openssh/.github/configs | 14 +-
crypto/openssh/.github/setup_ci.sh | 53 +-
crypto/openssh/.github/workflows/c-cpp.yml | 15 +-
crypto/openssh/.github/workflows/selfhosted.yml | 21 +-
crypto/openssh/ChangeLog | 12792 +++++++++++-----------
crypto/openssh/Makefile.in | 14 +-
crypto/openssh/PROTOCOL | 23 +-
crypto/openssh/PROTOCOL.agent | 33 +-
crypto/openssh/README | 2 +-
crypto/openssh/auth2.c | 8 +-
crypto/openssh/authfd.c | 40 +-
crypto/openssh/authfd.h | 5 +-
crypto/openssh/channels.c | 36 +-
crypto/openssh/channels.h | 4 +-
crypto/openssh/cipher.c | 23 +-
crypto/openssh/cipher.h | 3 +-
crypto/openssh/clientloop.c | 34 +-
crypto/openssh/config.h | 9 +
crypto/openssh/configure.ac | 49 +-
crypto/openssh/contrib/redhat/openssh.spec | 34 +-
crypto/openssh/contrib/suse/openssh.spec | 2 +-
crypto/openssh/kex.c | 235 +-
crypto/openssh/kex.h | 7 +-
crypto/openssh/log.c | 6 +-
crypto/openssh/m4/openssh.m4 | 116 +-
crypto/openssh/misc.c | 41 +-
crypto/openssh/misc.h | 3 +-
crypto/openssh/moduli | 898 +-
crypto/openssh/monitor_wrap.c | 4 +-
crypto/openssh/mux.c | 4 +-
crypto/openssh/openbsd-compat/port-solaris.c | 24 +-
crypto/openssh/readconf.c | 57 +-
crypto/openssh/readconf.h | 7 +-
crypto/openssh/regress/Makefile | 10 +-
crypto/openssh/regress/agent-pkcs11-cert.sh | 92 +
crypto/openssh/regress/agent-pkcs11-restrict.sh | 193 +
crypto/openssh/regress/agent-pkcs11.sh | 82 +-
crypto/openssh/regress/conch-ciphers.sh | 11 +-
crypto/openssh/regress/dropbear-ciphers.sh | 33 +
crypto/openssh/regress/dropbear-kex.sh | 31 +
crypto/openssh/regress/forcecommand.sh | 56 +-
crypto/openssh/regress/sshsig.sh | 72 +-
crypto/openssh/regress/test-exec.sh | 169 +-
crypto/openssh/regress/unittests/Makefile | 3 +-
crypto/openssh/regress/unittests/Makefile.inc | 4 +-
crypto/openssh/scp.c | 12 +-
crypto/openssh/servconf.c | 40 +-
crypto/openssh/sftp-client.c | 4 +-
crypto/openssh/ssh-add.1 | 14 +-
crypto/openssh/ssh-add.c | 92 +-
crypto/openssh/ssh-agent.c | 241 +-
crypto/openssh/ssh-pkcs11-client.c | 56 +-
crypto/openssh/ssh-pkcs11.h | 5 +-
crypto/openssh/ssh.1 | 7 +-
crypto/openssh/ssh.c | 67 +-
crypto/openssh/ssh2.h | 3 +-
crypto/openssh/ssh_config.5 | 83 +-
crypto/openssh/ssh_namespace.h | 7 +-
crypto/openssh/sshconnect.c | 10 +-
crypto/openssh/sshconnect.h | 6 +-
crypto/openssh/sshconnect2.c | 63 +-
crypto/openssh/sshd.c | 4 +-
crypto/openssh/sshd_config | 2 +-
crypto/openssh/sshd_config.5 | 2 +-
crypto/openssh/sshkey.c | 40 +-
crypto/openssh/sshsig.c | 7 +-
crypto/openssh/version.h | 6 +-
secure/usr.bin/ssh-agent/Makefile | 2 +-
69 files changed, 8772 insertions(+), 7376 deletions(-)
diff --cc crypto/openssh/PROTOCOL
index ded935eb6752,1894d573d739..3d00efa90d61
--- a/crypto/openssh/PROTOCOL
+++ b/crypto/openssh/PROTOCOL
@@@ -137,7 -137,7 +137,7 @@@ than as a named global or channel reque
short packet lengths, which would not be possible with other
approaches.
--1.9 transport: strict key exchange extension
++1.10 transport: strict key exchange extension
OpenSSH supports a number of transport-layer hardening measures under
a "strict KEX" feature. This feature is signalled similarly to the
@@@ -163,6 -163,25 +163,25 @@@ b) After sending or receiving a SSH2_MS
duration of the connection (i.e. not just the first
SSH2_MSG_NEWKEYS).
-1.10 transport: SSH2_MSG_EXT_INFO during user authentication
++1.11 transport: SSH2_MSG_EXT_INFO during user authentication
+
+ This protocol extension allows the SSH2_MSG_EXT_INFO to be sent
+ during user authentication. RFC8308 does allow a second
+ SSH2_MSG_EXT_INFO notification, but it may only be sent at the end
+ of user authentication and this is too late to signal per-user
+ server signature algorithms.
+
+ Support for receiving the SSH2_MSG_EXT_INFO message during user
+ authentication is signalled by the client including a
+ "ext-info-in-auth@openssh.com" key via its initial SSH2_MSG_EXT_INFO
+ set after the SSH2_MSG_NEWKEYS message.
+
+ A server that supports this extension MAY send a second
+ SSH2_MSG_EXT_INFO message any time after the client's first
+ SSH2_MSG_USERAUTH_REQUEST, regardless of whether it succeed or fails.
+ The client SHOULD be prepared to update the server-sig-algs that
+ it received during an earlier SSH2_MSG_EXT_INFO with the later one.
+
2. Connection protocol changes
2.1. connection: Channel write close extension "eow@openssh.com"
diff --cc crypto/openssh/auth2.c
index d2a420d0deec,000000000000..859dd25c5325
mode 100644,000000..100644
--- a/crypto/openssh/auth2.c
+++ b/crypto/openssh/auth2.c
@@@ -1,854 -1,0 +1,860 @@@
- /* $OpenBSD: auth2.c,v 1.167 2023/08/28 09:48:11 djm Exp $ */
++/* $OpenBSD: auth2.c,v 1.168 2023/12/18 14:45:49 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"
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/uio.h>
+
+#include <fcntl.h>
+#include <limits.h>
+#include <pwd.h>
+#include <stdarg.h>
+#include <string.h>
+#include <unistd.h>
+#include <time.h>
+
+#include "stdlib.h"
+#include "atomicio.h"
+#include "xmalloc.h"
+#include "ssh2.h"
+#include "packet.h"
+#include "log.h"
+#include "sshbuf.h"
+#include "misc.h"
+#include "servconf.h"
+#include "sshkey.h"
+#include "hostfile.h"
+#include "auth.h"
+#include "dispatch.h"
+#include "pathnames.h"
+#include "ssherr.h"
+#include "blacklist_client.h"
+#ifdef GSSAPI
+#include "ssh-gss.h"
+#endif
+#include "monitor_wrap.h"
+#include "digest.h"
++#include "kex.h"
+
+/* import */
+extern ServerOptions options;
+extern struct sshbuf *loginmsg;
+
+/* methods */
+
+extern Authmethod method_none;
+extern Authmethod method_pubkey;
+extern Authmethod method_passwd;
+extern Authmethod method_kbdint;
+extern Authmethod method_hostbased;
+#ifdef GSSAPI
+extern Authmethod method_gssapi;
+#endif
+
+Authmethod *authmethods[] = {
+ &method_none,
+ &method_pubkey,
+#ifdef GSSAPI
+ &method_gssapi,
+#endif
+ &method_passwd,
+ &method_kbdint,
+ &method_hostbased,
+ NULL
+};
+
+/* protocol */
+
+static int input_service_request(int, u_int32_t, struct ssh *);
+static int input_userauth_request(int, u_int32_t, struct ssh *);
+
+/* helper */
+static Authmethod *authmethod_byname(const char *);
+static Authmethod *authmethod_lookup(Authctxt *, const char *);
+static char *authmethods_get(Authctxt *authctxt);
+
+#define MATCH_NONE 0 /* method or submethod mismatch */
+#define MATCH_METHOD 1 /* method matches (no submethod specified) */
+#define MATCH_BOTH 2 /* method and submethod match */
+#define MATCH_PARTIAL 3 /* method matches, submethod can't be checked */
+static int list_starts_with(const char *, const char *, const char *);
+
+char *
+auth2_read_banner(void)
+{
+ struct stat st;
+ char *banner = NULL;
+ size_t len, n;
+ int fd;
+
+ if ((fd = open(options.banner, O_RDONLY)) == -1)
+ return (NULL);
+ if (fstat(fd, &st) == -1) {
+ close(fd);
+ return (NULL);
+ }
+ if (st.st_size <= 0 || st.st_size > 1*1024*1024) {
+ close(fd);
+ return (NULL);
+ }
+
+ len = (size_t)st.st_size; /* truncate */
+ banner = xmalloc(len + 1);
+ n = atomicio(read, fd, banner, len);
+ close(fd);
+
+ if (n != len) {
+ free(banner);
+ return (NULL);
+ }
+ banner[n] = '\0';
+
+ return (banner);
+}
+
+static void
+userauth_send_banner(struct ssh *ssh, const char *msg)
+{
+ int r;
+
+ if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_BANNER)) != 0 ||
+ (r = sshpkt_put_cstring(ssh, msg)) != 0 ||
+ (r = sshpkt_put_cstring(ssh, "")) != 0 || /* language, unused */
+ (r = sshpkt_send(ssh)) != 0)
+ fatal_fr(r, "send packet");
+ debug("%s: sent", __func__);
+}
+
+static void
+userauth_banner(struct ssh *ssh)
+{
+ char *banner = NULL;
+
+ if (options.banner == NULL)
+ return;
+
+ if ((banner = PRIVSEP(auth2_read_banner())) == NULL)
+ goto done;
+ userauth_send_banner(ssh, banner);
+
+done:
+ free(banner);
+}
+
+/*
+ * loop until authctxt->success == TRUE
+ */
+void
+do_authentication2(struct ssh *ssh)
+{
+ Authctxt *authctxt = ssh->authctxt;
+
+ ssh_dispatch_init(ssh, &dispatch_protocol_error);
++ if (ssh->kex->ext_info_c)
++ ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &kex_input_ext_info);
+ ssh_dispatch_set(ssh, SSH2_MSG_SERVICE_REQUEST, &input_service_request);
+ ssh_dispatch_run_fatal(ssh, DISPATCH_BLOCK, &authctxt->success);
+ ssh->authctxt = NULL;
+}
+
+static int
+input_service_request(int type, u_int32_t seq, struct ssh *ssh)
+{
+ Authctxt *authctxt = ssh->authctxt;
+ char *service = NULL;
+ int r, acceptit = 0;
+
+ if ((r = sshpkt_get_cstring(ssh, &service, NULL)) != 0 ||
+ (r = sshpkt_get_end(ssh)) != 0)
+ goto out;
+
+ if (authctxt == NULL)
+ fatal("input_service_request: no authctxt");
+
+ if (strcmp(service, "ssh-userauth") == 0) {
+ if (!authctxt->success) {
+ acceptit = 1;
+ /* now we can handle user-auth requests */
+ ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_REQUEST,
+ &input_userauth_request);
+ }
+ }
+ /* XXX all other service requests are denied */
+
+ if (acceptit) {
+ if ((r = sshpkt_start(ssh, SSH2_MSG_SERVICE_ACCEPT)) != 0 ||
+ (r = sshpkt_put_cstring(ssh, service)) != 0 ||
+ (r = sshpkt_send(ssh)) != 0 ||
+ (r = ssh_packet_write_wait(ssh)) != 0)
+ goto out;
+ } else {
+ debug("bad service request %s", service);
+ ssh_packet_disconnect(ssh, "bad service request %s", service);
+ }
++ ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &dispatch_protocol_error);
+ r = 0;
+ out:
+ free(service);
+ return r;
+}
+
+#define MIN_FAIL_DELAY_SECONDS 0.005
+#define MAX_FAIL_DELAY_SECONDS 5.0
+static double
+user_specific_delay(const char *user)
+{
+ char b[512];
+ size_t len = ssh_digest_bytes(SSH_DIGEST_SHA512);
+ u_char *hash = xmalloc(len);
+ double delay;
+
+ (void)snprintf(b, sizeof b, "%llu%s",
+ (unsigned long long)options.timing_secret, user);
+ if (ssh_digest_memory(SSH_DIGEST_SHA512, b, strlen(b), hash, len) != 0)
+ fatal_f("ssh_digest_memory");
+ /* 0-4.2 ms of delay */
+ delay = (double)PEEK_U32(hash) / 1000 / 1000 / 1000 / 1000;
+ freezero(hash, len);
+ debug3_f("user specific delay %0.3lfms", delay/1000);
+ return MIN_FAIL_DELAY_SECONDS + delay;
+}
+
+static void
+ensure_minimum_time_since(double start, double seconds)
+{
+ struct timespec ts;
+ double elapsed = monotime_double() - start, req = seconds, remain;
+
+ if (elapsed > MAX_FAIL_DELAY_SECONDS) {
+ debug3_f("elapsed %0.3lfms exceeded the max delay "
+ "requested %0.3lfms)", elapsed*1000, req*1000);
+ return;
+ }
+
+ /* if we've already passed the requested time, scale up */
+ while ((remain = seconds - elapsed) < 0.0)
+ seconds *= 2;
+
+ ts.tv_sec = remain;
+ ts.tv_nsec = (remain - ts.tv_sec) * 1000000000;
+ debug3_f("elapsed %0.3lfms, delaying %0.3lfms (requested %0.3lfms)",
+ elapsed*1000, remain*1000, req*1000);
+ nanosleep(&ts, NULL);
+}
+
+static int
+input_userauth_request(int type, u_int32_t seq, struct ssh *ssh)
+{
+ Authctxt *authctxt = ssh->authctxt;
+ Authmethod *m = NULL;
+ char *user = NULL, *service = NULL, *method = NULL, *style = NULL;
+ int r, authenticated = 0;
+ double tstart = monotime_double();
+
+ if (authctxt == NULL)
+ fatal("input_userauth_request: no authctxt");
+
+ if ((r = sshpkt_get_cstring(ssh, &user, NULL)) != 0 ||
+ (r = sshpkt_get_cstring(ssh, &service, NULL)) != 0 ||
+ (r = sshpkt_get_cstring(ssh, &method, NULL)) != 0)
+ goto out;
+ debug("userauth-request for user %s service %s method %s", user, service, method);
+ debug("attempt %d failures %d", authctxt->attempt, authctxt->failures);
+
+ if ((style = strchr(user, ':')) != NULL)
+ *style++ = 0;
+
+ if (authctxt->attempt >= 1024)
+ auth_maxtries_exceeded(ssh);
+ if (authctxt->attempt++ == 0) {
+ /* setup auth context */
+ authctxt->pw = PRIVSEP(getpwnamallow(ssh, user));
+ authctxt->user = xstrdup(user);
+ if (authctxt->pw && strcmp(service, "ssh-connection")==0) {
+ authctxt->valid = 1;
+ debug2_f("setting up authctxt for %s", user);
+ } else {
+ authctxt->valid = 0;
+ /* Invalid user, fake password information */
+ authctxt->pw = fakepw();
+#ifdef SSH_AUDIT_EVENTS
+ PRIVSEP(audit_event(ssh, SSH_INVALID_USER));
+#endif
+ }
+#ifdef USE_PAM
+ if (options.use_pam)
+ PRIVSEP(start_pam(ssh));
+#endif
+ ssh_packet_set_log_preamble(ssh, "%suser %s",
+ authctxt->valid ? "authenticating " : "invalid ", user);
+ setproctitle("%s%s", authctxt->valid ? user : "unknown",
+ use_privsep ? " [net]" : "");
+ authctxt->service = xstrdup(service);
+ authctxt->style = style ? xstrdup(style) : NULL;
+ if (use_privsep)
+ mm_inform_authserv(service, style);
+ userauth_banner(ssh);
++ if ((r = kex_server_update_ext_info(ssh)) != 0)
++ fatal_fr(r, "kex_server_update_ext_info failed");
+ if (auth2_setup_methods_lists(authctxt) != 0)
+ ssh_packet_disconnect(ssh,
+ "no authentication methods enabled");
+ } else if (strcmp(user, authctxt->user) != 0 ||
+ strcmp(service, authctxt->service) != 0) {
+ ssh_packet_disconnect(ssh, "Change of username or service "
+ "not allowed: (%s,%s) -> (%s,%s)",
+ authctxt->user, authctxt->service, user, service);
+ }
+ /* reset state */
+ auth2_challenge_stop(ssh);
+
+#ifdef GSSAPI
+ /* XXX move to auth2_gssapi_stop() */
+ ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
+ ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
+#endif
+
+ auth2_authctxt_reset_info(authctxt);
+ authctxt->postponed = 0;
+ authctxt->server_caused_failure = 0;
+
+ /* try to authenticate user */
+ m = authmethod_lookup(authctxt, method);
+ if (m != NULL && authctxt->failures < options.max_authtries) {
+ debug2("input_userauth_request: try method %s", method);
+ authenticated = m->userauth(ssh, method);
+ }
+ if (!authctxt->authenticated && strcmp(method, "none") != 0)
+ ensure_minimum_time_since(tstart,
+ user_specific_delay(authctxt->user));
+ userauth_finish(ssh, authenticated, method, NULL);
+ r = 0;
+ out:
+ free(service);
+ free(user);
+ free(method);
+ return r;
+}
+
+void
+userauth_finish(struct ssh *ssh, int authenticated, const char *packet_method,
+ const char *submethod)
+{
+ Authctxt *authctxt = ssh->authctxt;
+ Authmethod *m = NULL;
+ const char *method = packet_method;
+ char *methods;
+ int r, partial = 0;
+
+ if (authenticated) {
+ if (!authctxt->valid) {
+ fatal("INTERNAL ERROR: authenticated invalid user %s",
+ authctxt->user);
+ }
+ if (authctxt->postponed)
+ fatal("INTERNAL ERROR: authenticated and postponed");
+ /* prefer primary authmethod name to possible synonym */
+ if ((m = authmethod_byname(method)) == NULL)
+ fatal("INTERNAL ERROR: bad method %s", method);
+ method = m->name;
+ }
+
+ /* Special handling for root */
+ if (authenticated && authctxt->pw->pw_uid == 0 &&
+ !auth_root_allowed(ssh, method)) {
+ authenticated = 0;
+#ifdef SSH_AUDIT_EVENTS
+ PRIVSEP(audit_event(ssh, SSH_LOGIN_ROOT_DENIED));
+#endif
+ }
+
+ if (authenticated && options.num_auth_methods != 0) {
+ if (!auth2_update_methods_lists(authctxt, method, submethod)) {
+ authenticated = 0;
+ partial = 1;
+ }
+ }
+
+ /* Log before sending the reply */
+ auth_log(ssh, authenticated, partial, method, submethod);
+
+ /* Update information exposed to session */
+ if (authenticated || partial)
+ auth2_update_session_info(authctxt, method, submethod);
+
+ if (authctxt->postponed)
+ return;
+
+#ifdef USE_PAM
+ if (options.use_pam && authenticated) {
+ int r, success = PRIVSEP(do_pam_account());
+
+ /* If PAM returned a message, send it to the user. */
+ if (sshbuf_len(loginmsg) > 0) {
+ if ((r = sshbuf_put(loginmsg, "\0", 1)) != 0)
+ fatal("%s: buffer error: %s",
+ __func__, ssh_err(r));
+ userauth_send_banner(ssh, sshbuf_ptr(loginmsg));
+ if ((r = ssh_packet_write_wait(ssh)) != 0) {
+ sshpkt_fatal(ssh, r,
+ "%s: send PAM banner", __func__);
+ }
+ }
+ if (!success) {
+ fatal("Access denied for user %s by PAM account "
+ "configuration", authctxt->user);
+ }
+ }
+#endif
+
+ if (authenticated == 1) {
+ /* turn off userauth */
+ ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_REQUEST,
+ &dispatch_protocol_ignore);
+ if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_SUCCESS)) != 0 ||
+ (r = sshpkt_send(ssh)) != 0 ||
+ (r = ssh_packet_write_wait(ssh)) != 0)
+ fatal_fr(r, "send success packet");
+ /* now we can break out */
+ authctxt->success = 1;
+ ssh_packet_set_log_preamble(ssh, "user %s", authctxt->user);
+ } else {
+ /* Allow initial try of "none" auth without failure penalty */
+ if (!partial && !authctxt->server_caused_failure &&
+ (authctxt->attempt > 1 || strcmp(method, "none") != 0)) {
+ authctxt->failures++;
+ BLACKLIST_NOTIFY(ssh, BLACKLIST_AUTH_FAIL, "ssh");
+ }
+ if (authctxt->failures >= options.max_authtries) {
+#ifdef SSH_AUDIT_EVENTS
+ PRIVSEP(audit_event(ssh, SSH_LOGIN_EXCEED_MAXTRIES));
+#endif
+ auth_maxtries_exceeded(ssh);
+ }
+ methods = authmethods_get(authctxt);
+ debug3_f("failure partial=%d next methods=\"%s\"",
+ partial, methods);
+ if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_FAILURE)) != 0 ||
+ (r = sshpkt_put_cstring(ssh, methods)) != 0 ||
+ (r = sshpkt_put_u8(ssh, partial)) != 0 ||
+ (r = sshpkt_send(ssh)) != 0 ||
+ (r = ssh_packet_write_wait(ssh)) != 0)
+ fatal_fr(r, "send failure packet");
+ free(methods);
+ }
+}
+
+/*
+ * Checks whether method is allowed by at least one AuthenticationMethods
+ * methods list. Returns 1 if allowed, or no methods lists configured.
+ * 0 otherwise.
+ */
+int
+auth2_method_allowed(Authctxt *authctxt, const char *method,
+ const char *submethod)
+{
+ u_int i;
+
+ /*
+ * NB. authctxt->num_auth_methods might be zero as a result of
+ * auth2_setup_methods_lists(), so check the configuration.
+ */
+ if (options.num_auth_methods == 0)
+ return 1;
+ for (i = 0; i < authctxt->num_auth_methods; i++) {
+ if (list_starts_with(authctxt->auth_methods[i], method,
+ submethod) != MATCH_NONE)
+ return 1;
+ }
+ return 0;
+}
+
+static char *
+authmethods_get(Authctxt *authctxt)
+{
+ struct sshbuf *b;
+ char *list;
+ int i, r;
+
+ if ((b = sshbuf_new()) == NULL)
+ fatal_f("sshbuf_new failed");
+ for (i = 0; authmethods[i] != NULL; i++) {
+ if (strcmp(authmethods[i]->name, "none") == 0)
+ continue;
+ if (authmethods[i]->enabled == NULL ||
+ *(authmethods[i]->enabled) == 0)
+ continue;
+ if (!auth2_method_allowed(authctxt, authmethods[i]->name,
+ NULL))
+ continue;
+ if ((r = sshbuf_putf(b, "%s%s", sshbuf_len(b) ? "," : "",
+ authmethods[i]->name)) != 0)
+ fatal_fr(r, "buffer error");
+ }
+ if ((list = sshbuf_dup_string(b)) == NULL)
+ fatal_f("sshbuf_dup_string failed");
+ sshbuf_free(b);
+ return list;
+}
+
+static Authmethod *
+authmethod_byname(const char *name)
+{
+ int i;
+
+ if (name == NULL)
+ fatal_f("NULL authentication method name");
+ for (i = 0; authmethods[i] != NULL; i++) {
+ if (strcmp(name, authmethods[i]->name) == 0 ||
+ (authmethods[i]->synonym != NULL &&
+ strcmp(name, authmethods[i]->synonym) == 0))
+ return authmethods[i];
+ }
+ debug_f("unrecognized authentication method name: %s", name);
+ return NULL;
+}
+
+static Authmethod *
+authmethod_lookup(Authctxt *authctxt, const char *name)
+{
+ Authmethod *method;
+
+ if ((method = authmethod_byname(name)) == NULL)
+ return NULL;
+
+ if (method->enabled == NULL || *(method->enabled) == 0) {
+ debug3_f("method %s not enabled", name);
+ return NULL;
+ }
+ if (!auth2_method_allowed(authctxt, method->name, NULL)) {
+ debug3_f("method %s not allowed "
+ "by AuthenticationMethods", name);
+ return NULL;
+ }
+ return method;
+}
+
+/*
+ * Check a comma-separated list of methods for validity. Is need_enable is
+ * non-zero, then also require that the methods are enabled.
+ * Returns 0 on success or -1 if the methods list is invalid.
+ */
+int
+auth2_methods_valid(const char *_methods, int need_enable)
+{
+ char *methods, *omethods, *method, *p;
+ u_int i, found;
+ int ret = -1;
+
+ if (*_methods == '\0') {
+ error("empty authentication method list");
+ return -1;
+ }
+ omethods = methods = xstrdup(_methods);
+ while ((method = strsep(&methods, ",")) != NULL) {
+ for (found = i = 0; !found && authmethods[i] != NULL; i++) {
+ if ((p = strchr(method, ':')) != NULL)
+ *p = '\0';
+ if (strcmp(method, authmethods[i]->name) != 0)
+ continue;
+ if (need_enable) {
+ if (authmethods[i]->enabled == NULL ||
+ *(authmethods[i]->enabled) == 0) {
+ error("Disabled method \"%s\" in "
+ "AuthenticationMethods list \"%s\"",
+ method, _methods);
+ goto out;
+ }
+ }
+ found = 1;
+ break;
+ }
+ if (!found) {
+ error("Unknown authentication method \"%s\" in list",
+ method);
+ goto out;
+ }
+ }
+ ret = 0;
+ out:
+ free(omethods);
+ return ret;
+}
+
+/*
+ * Prune the AuthenticationMethods supplied in the configuration, removing
+ * any methods lists that include disabled methods. Note that this might
+ * leave authctxt->num_auth_methods == 0, even when multiple required auth
+ * has been requested. For this reason, all tests for whether multiple is
+ * enabled should consult options.num_auth_methods directly.
+ */
+int
+auth2_setup_methods_lists(Authctxt *authctxt)
+{
+ u_int i;
+
+ /* First, normalise away the "any" pseudo-method */
+ if (options.num_auth_methods == 1 &&
+ strcmp(options.auth_methods[0], "any") == 0) {
+ free(options.auth_methods[0]);
+ options.auth_methods[0] = NULL;
+ options.num_auth_methods = 0;
+ }
+
+ if (options.num_auth_methods == 0)
+ return 0;
+ debug3_f("checking methods");
+ authctxt->auth_methods = xcalloc(options.num_auth_methods,
+ sizeof(*authctxt->auth_methods));
+ authctxt->num_auth_methods = 0;
+ for (i = 0; i < options.num_auth_methods; i++) {
+ if (auth2_methods_valid(options.auth_methods[i], 1) != 0) {
+ logit("Authentication methods list \"%s\" contains "
+ "disabled method, skipping",
+ options.auth_methods[i]);
+ continue;
+ }
+ debug("authentication methods list %d: %s",
+ authctxt->num_auth_methods, options.auth_methods[i]);
+ authctxt->auth_methods[authctxt->num_auth_methods++] =
+ xstrdup(options.auth_methods[i]);
+ }
+ if (authctxt->num_auth_methods == 0) {
+ error("No AuthenticationMethods left after eliminating "
+ "disabled methods");
+ return -1;
+ }
+ return 0;
+}
+
+static int
+list_starts_with(const char *methods, const char *method,
+ const char *submethod)
+{
+ size_t l = strlen(method);
+ int match;
+ const char *p;
+
+ if (strncmp(methods, method, l) != 0)
+ return MATCH_NONE;
+ p = methods + l;
+ match = MATCH_METHOD;
+ if (*p == ':') {
+ if (!submethod)
+ return MATCH_PARTIAL;
+ l = strlen(submethod);
+ p += 1;
+ if (strncmp(submethod, p, l))
+ return MATCH_NONE;
+ p += l;
+ match = MATCH_BOTH;
+ }
+ if (*p != ',' && *p != '\0')
+ return MATCH_NONE;
+ return match;
+}
+
+/*
+ * Remove method from the start of a comma-separated list of methods.
+ * Returns 0 if the list of methods did not start with that method or 1
+ * if it did.
+ */
+static int
+remove_method(char **methods, const char *method, const char *submethod)
+{
+ char *omethods = *methods, *p;
+ size_t l = strlen(method);
+ int match;
+
+ match = list_starts_with(omethods, method, submethod);
+ if (match != MATCH_METHOD && match != MATCH_BOTH)
+ return 0;
+ p = omethods + l;
+ if (submethod && match == MATCH_BOTH)
+ p += 1 + strlen(submethod); /* include colon */
+ if (*p == ',')
+ p++;
+ *methods = xstrdup(p);
+ free(omethods);
+ return 1;
+}
+
+/*
+ * Called after successful authentication. Will remove the successful method
+ * from the start of each list in which it occurs. If it was the last method
+ * in any list, then authentication is deemed successful.
+ * Returns 1 if the method completed any authentication list or 0 otherwise.
+ */
+int
+auth2_update_methods_lists(Authctxt *authctxt, const char *method,
+ const char *submethod)
+{
+ u_int i, found = 0;
+
+ debug3_f("updating methods list after \"%s\"", method);
+ for (i = 0; i < authctxt->num_auth_methods; i++) {
+ if (!remove_method(&(authctxt->auth_methods[i]), method,
+ submethod))
+ continue;
+ found = 1;
+ if (*authctxt->auth_methods[i] == '\0') {
+ debug2("authentication methods list %d complete", i);
+ return 1;
+ }
+ debug3("authentication methods list %d remaining: \"%s\"",
+ i, authctxt->auth_methods[i]);
+ }
+ /* This should not happen, but would be bad if it did */
+ if (!found)
+ fatal_f("method not in AuthenticationMethods");
+ return 0;
+}
+
+/* Reset method-specific information */
+void auth2_authctxt_reset_info(Authctxt *authctxt)
+{
+ sshkey_free(authctxt->auth_method_key);
+ free(authctxt->auth_method_info);
+ authctxt->auth_method_key = NULL;
+ authctxt->auth_method_info = NULL;
+}
+
+/* Record auth method-specific information for logs */
+void
+auth2_record_info(Authctxt *authctxt, const char *fmt, ...)
+{
+ va_list ap;
+ int i;
+
+ free(authctxt->auth_method_info);
+ authctxt->auth_method_info = NULL;
+
+ va_start(ap, fmt);
+ i = vasprintf(&authctxt->auth_method_info, fmt, ap);
+ va_end(ap);
+
+ if (i == -1)
+ fatal_f("vasprintf failed");
+}
+
+/*
+ * Records a public key used in authentication. This is used for logging
+ * and to ensure that the same key is not subsequently accepted again for
+ * multiple authentication.
+ */
+void
+auth2_record_key(Authctxt *authctxt, int authenticated,
+ const struct sshkey *key)
+{
+ struct sshkey **tmp, *dup;
+ int r;
+
+ if ((r = sshkey_from_private(key, &dup)) != 0)
+ fatal_fr(r, "copy key");
+ sshkey_free(authctxt->auth_method_key);
+ authctxt->auth_method_key = dup;
+
+ if (!authenticated)
+ return;
+
+ /* If authenticated, make sure we don't accept this key again */
+ if ((r = sshkey_from_private(key, &dup)) != 0)
+ fatal_fr(r, "copy key");
+ if (authctxt->nprev_keys >= INT_MAX ||
+ (tmp = recallocarray(authctxt->prev_keys, authctxt->nprev_keys,
+ authctxt->nprev_keys + 1, sizeof(*authctxt->prev_keys))) == NULL)
+ fatal_f("reallocarray failed");
+ authctxt->prev_keys = tmp;
+ authctxt->prev_keys[authctxt->nprev_keys] = dup;
+ authctxt->nprev_keys++;
+
+}
+
+/* Checks whether a key has already been previously used for authentication */
+int
+auth2_key_already_used(Authctxt *authctxt, const struct sshkey *key)
+{
+ u_int i;
+ char *fp;
+
+ for (i = 0; i < authctxt->nprev_keys; i++) {
+ if (sshkey_equal_public(key, authctxt->prev_keys[i])) {
+ fp = sshkey_fingerprint(authctxt->prev_keys[i],
+ options.fingerprint_hash, SSH_FP_DEFAULT);
+ debug3_f("key already used: %s %s",
+ sshkey_type(authctxt->prev_keys[i]),
+ fp == NULL ? "UNKNOWN" : fp);
+ free(fp);
+ return 1;
+ }
+ }
+ return 0;
+}
+
+/*
+ * Updates authctxt->session_info with details of authentication. Should be
+ * whenever an authentication method succeeds.
+ */
+void
+auth2_update_session_info(Authctxt *authctxt, const char *method,
+ const char *submethod)
+{
+ int r;
+
+ if (authctxt->session_info == NULL) {
+ if ((authctxt->session_info = sshbuf_new()) == NULL)
+ fatal_f("sshbuf_new");
+ }
+
+ /* Append method[/submethod] */
+ if ((r = sshbuf_putf(authctxt->session_info, "%s%s%s",
+ method, submethod == NULL ? "" : "/",
+ submethod == NULL ? "" : submethod)) != 0)
+ fatal_fr(r, "append method");
+
+ /* Append key if present */
+ if (authctxt->auth_method_key != NULL) {
+ if ((r = sshbuf_put_u8(authctxt->session_info, ' ')) != 0 ||
+ (r = sshkey_format_text(authctxt->auth_method_key,
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