summaryrefslogtreecommitdiffstats
path: root/monitor.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--monitor.c1955
1 files changed, 1955 insertions, 0 deletions
diff --git a/monitor.c b/monitor.c
new file mode 100644
index 0000000..91e0e62
--- /dev/null
+++ b/monitor.c
@@ -0,0 +1,1955 @@
+/* $OpenBSD: monitor.c,v 1.234 2022/06/15 16:08:25 djm Exp $ */
+/*
+ * Copyright 2002 Niels Provos <provos@citi.umich.edu>
+ * Copyright 2002 Markus Friedl <markus@openbsd.org>
+ * 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/socket.h>
+#include <sys/wait.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#ifdef HAVE_PATHS_H
+#include <paths.h>
+#endif
+#include <pwd.h>
+#include <signal.h>
+#ifdef HAVE_STDINT_H
+# include <stdint.h>
+#endif
+#include <stdlib.h>
+#include <string.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <unistd.h>
+#ifdef HAVE_POLL_H
+#include <poll.h>
+#else
+# ifdef HAVE_SYS_POLL_H
+# include <sys/poll.h>
+# endif
+#endif
+
+#ifdef WITH_OPENSSL
+#include <openssl/dh.h>
+#endif
+
+#include "openbsd-compat/sys-tree.h"
+#include "openbsd-compat/sys-queue.h"
+#include "openbsd-compat/openssl-compat.h"
+
+#include "atomicio.h"
+#include "xmalloc.h"
+#include "ssh.h"
+#include "sshkey.h"
+#include "sshbuf.h"
+#include "hostfile.h"
+#include "auth.h"
+#include "cipher.h"
+#include "kex.h"
+#include "dh.h"
+#include "auth-pam.h"
+#include "packet.h"
+#include "auth-options.h"
+#include "sshpty.h"
+#include "channels.h"
+#include "session.h"
+#include "sshlogin.h"
+#include "canohost.h"
+#include "log.h"
+#include "misc.h"
+#include "servconf.h"
+#include "monitor.h"
+#ifdef GSSAPI
+#include "ssh-gss.h"
+#endif
+#include "monitor_wrap.h"
+#include "monitor_fdpass.h"
+#include "compat.h"
+#include "ssh2.h"
+#include "authfd.h"
+#include "match.h"
+#include "ssherr.h"
+#include "sk-api.h"
+
+#ifdef GSSAPI
+static Gssctxt *gsscontext = NULL;
+#endif
+
+/* Imports */
+extern ServerOptions options;
+extern u_int utmp_len;
+extern struct sshbuf *loginmsg;
+extern struct sshauthopt *auth_opts; /* XXX move to permanent ssh->authctxt? */
+
+/* State exported from the child */
+static struct sshbuf *child_state;
+
+/* Functions on the monitor that answer unprivileged requests */
+
+int mm_answer_moduli(struct ssh *, int, struct sshbuf *);
+int mm_answer_sign(struct ssh *, int, struct sshbuf *);
+int mm_answer_pwnamallow(struct ssh *, int, struct sshbuf *);
+int mm_answer_auth2_read_banner(struct ssh *, int, struct sshbuf *);
+int mm_answer_authserv(struct ssh *, int, struct sshbuf *);
+int mm_answer_authpassword(struct ssh *, int, struct sshbuf *);
+int mm_answer_bsdauthquery(struct ssh *, int, struct sshbuf *);
+int mm_answer_bsdauthrespond(struct ssh *, int, struct sshbuf *);
+int mm_answer_keyallowed(struct ssh *, int, struct sshbuf *);
+int mm_answer_keyverify(struct ssh *, int, struct sshbuf *);
+int mm_answer_pty(struct ssh *, int, struct sshbuf *);
+int mm_answer_pty_cleanup(struct ssh *, int, struct sshbuf *);
+int mm_answer_term(struct ssh *, int, struct sshbuf *);
+int mm_answer_rsa_keyallowed(struct ssh *, int, struct sshbuf *);
+int mm_answer_rsa_challenge(struct ssh *, int, struct sshbuf *);
+int mm_answer_rsa_response(struct ssh *, int, struct sshbuf *);
+int mm_answer_sesskey(struct ssh *, int, struct sshbuf *);
+int mm_answer_sessid(struct ssh *, int, struct sshbuf *);
+
+#ifdef USE_PAM
+int mm_answer_pam_start(struct ssh *, int, struct sshbuf *);
+int mm_answer_pam_account(struct ssh *, int, struct sshbuf *);
+int mm_answer_pam_init_ctx(struct ssh *, int, struct sshbuf *);
+int mm_answer_pam_query(struct ssh *, int, struct sshbuf *);
+int mm_answer_pam_respond(struct ssh *, int, struct sshbuf *);
+int mm_answer_pam_free_ctx(struct ssh *, int, struct sshbuf *);
+#endif
+
+#ifdef GSSAPI
+int mm_answer_gss_setup_ctx(struct ssh *, int, struct sshbuf *);
+int mm_answer_gss_accept_ctx(struct ssh *, int, struct sshbuf *);
+int mm_answer_gss_userok(struct ssh *, int, struct sshbuf *);
+int mm_answer_gss_checkmic(struct ssh *, int, struct sshbuf *);
+#endif
+
+#ifdef SSH_AUDIT_EVENTS
+int mm_answer_audit_event(struct ssh *, int, struct sshbuf *);
+int mm_answer_audit_command(struct ssh *, int, struct sshbuf *);
+#endif
+
+static Authctxt *authctxt;
+
+/* local state for key verify */
+static u_char *key_blob = NULL;
+static size_t key_bloblen = 0;
+static u_int key_blobtype = MM_NOKEY;
+static struct sshauthopt *key_opts = NULL;
+static char *hostbased_cuser = NULL;
+static char *hostbased_chost = NULL;
+static char *auth_method = "unknown";
+static char *auth_submethod = NULL;
+static u_int session_id2_len = 0;
+static u_char *session_id2 = NULL;
+static pid_t monitor_child_pid;
+
+struct mon_table {
+ enum monitor_reqtype type;
+ int flags;
+ int (*f)(struct ssh *, int, struct sshbuf *);
+};
+
+#define MON_ISAUTH 0x0004 /* Required for Authentication */
+#define MON_AUTHDECIDE 0x0008 /* Decides Authentication */
+#define MON_ONCE 0x0010 /* Disable after calling */
+#define MON_ALOG 0x0020 /* Log auth attempt without authenticating */
+
+#define MON_AUTH (MON_ISAUTH|MON_AUTHDECIDE)
+
+#define MON_PERMIT 0x1000 /* Request is permitted */
+
+static int monitor_read(struct ssh *, struct monitor *, struct mon_table *,
+ struct mon_table **);
+static int monitor_read_log(struct monitor *);
+
+struct mon_table mon_dispatch_proto20[] = {
+#ifdef WITH_OPENSSL
+ {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli},
+#endif
+ {MONITOR_REQ_SIGN, MON_ONCE, mm_answer_sign},
+ {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
+ {MONITOR_REQ_AUTHSERV, MON_ONCE, mm_answer_authserv},
+ {MONITOR_REQ_AUTH2_READ_BANNER, MON_ONCE, mm_answer_auth2_read_banner},
+ {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
+#ifdef USE_PAM
+ {MONITOR_REQ_PAM_START, MON_ONCE, mm_answer_pam_start},
+ {MONITOR_REQ_PAM_ACCOUNT, 0, mm_answer_pam_account},
+ {MONITOR_REQ_PAM_INIT_CTX, MON_ONCE, mm_answer_pam_init_ctx},
+ {MONITOR_REQ_PAM_QUERY, 0, mm_answer_pam_query},
+ {MONITOR_REQ_PAM_RESPOND, MON_ONCE, mm_answer_pam_respond},
+ {MONITOR_REQ_PAM_FREE_CTX, MON_ONCE|MON_AUTHDECIDE, mm_answer_pam_free_ctx},
+#endif
+#ifdef SSH_AUDIT_EVENTS
+ {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
+#endif
+#ifdef BSD_AUTH
+ {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
+ {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH, mm_answer_bsdauthrespond},
+#endif
+ {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed},
+ {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify},
+#ifdef GSSAPI
+ {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx},
+ {MONITOR_REQ_GSSSTEP, 0, mm_answer_gss_accept_ctx},
+ {MONITOR_REQ_GSSUSEROK, MON_ONCE|MON_AUTHDECIDE, mm_answer_gss_userok},
+ {MONITOR_REQ_GSSCHECKMIC, MON_ONCE, mm_answer_gss_checkmic},
+#endif
+ {0, 0, NULL}
+};
+
+struct mon_table mon_dispatch_postauth20[] = {
+#ifdef WITH_OPENSSL
+ {MONITOR_REQ_MODULI, 0, mm_answer_moduli},
+#endif
+ {MONITOR_REQ_SIGN, 0, mm_answer_sign},
+ {MONITOR_REQ_PTY, 0, mm_answer_pty},
+ {MONITOR_REQ_PTYCLEANUP, 0, mm_answer_pty_cleanup},
+ {MONITOR_REQ_TERM, 0, mm_answer_term},
+#ifdef SSH_AUDIT_EVENTS
+ {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event},
+ {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT, mm_answer_audit_command},
+#endif
+ {0, 0, NULL}
+};
+
+struct mon_table *mon_dispatch;
+
+/* Specifies if a certain message is allowed at the moment */
+static void
+monitor_permit(struct mon_table *ent, enum monitor_reqtype type, int permit)
+{
+ while (ent->f != NULL) {
+ if (ent->type == type) {
+ ent->flags &= ~MON_PERMIT;
+ ent->flags |= permit ? MON_PERMIT : 0;
+ return;
+ }
+ ent++;
+ }
+}
+
+static void
+monitor_permit_authentications(int permit)
+{
+ struct mon_table *ent = mon_dispatch;
+
+ while (ent->f != NULL) {
+ if (ent->flags & MON_AUTH) {
+ ent->flags &= ~MON_PERMIT;
+ ent->flags |= permit ? MON_PERMIT : 0;
+ }
+ ent++;
+ }
+}
+
+void
+monitor_child_preauth(struct ssh *ssh, struct monitor *pmonitor)
+{
+ struct mon_table *ent;
+ int authenticated = 0, partial = 0;
+
+ debug3("preauth child monitor started");
+
+ if (pmonitor->m_recvfd >= 0)
+ close(pmonitor->m_recvfd);
+ if (pmonitor->m_log_sendfd >= 0)
+ close(pmonitor->m_log_sendfd);
+ pmonitor->m_log_sendfd = pmonitor->m_recvfd = -1;
+
+ authctxt = (Authctxt *)ssh->authctxt;
+ memset(authctxt, 0, sizeof(*authctxt));
+ ssh->authctxt = authctxt;
+
+ authctxt->loginmsg = loginmsg;
+
+ mon_dispatch = mon_dispatch_proto20;
+ /* Permit requests for moduli and signatures */
+ monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
+ monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
+
+ /* The first few requests do not require asynchronous access */
+ while (!authenticated) {
+ partial = 0;
+ auth_method = "unknown";
+ auth_submethod = NULL;
+ auth2_authctxt_reset_info(authctxt);
+
+ authenticated = (monitor_read(ssh, pmonitor,
+ mon_dispatch, &ent) == 1);
+
+ /* Special handling for multiple required authentications */
+ if (options.num_auth_methods != 0) {
+ if (authenticated &&
+ !auth2_update_methods_lists(authctxt,
+ auth_method, auth_submethod)) {
+ debug3_f("method %s: partial", auth_method);
+ authenticated = 0;
+ partial = 1;
+ }
+ }
+
+ if (authenticated) {
+ if (!(ent->flags & MON_AUTHDECIDE))
+ fatal_f("unexpected authentication from %d",
+ ent->type);
+ if (authctxt->pw->pw_uid == 0 &&
+ !auth_root_allowed(ssh, auth_method))
+ authenticated = 0;
+#ifdef USE_PAM
+ /* PAM needs to perform account checks after auth */
+ if (options.use_pam && authenticated) {
+ struct sshbuf *m;
+
+ if ((m = sshbuf_new()) == NULL)
+ fatal("%s: sshbuf_new failed",
+ __func__);
+ mm_request_receive_expect(pmonitor->m_sendfd,
+ MONITOR_REQ_PAM_ACCOUNT, m);
+ authenticated = mm_answer_pam_account(
+ ssh, pmonitor->m_sendfd, m);
+ sshbuf_free(m);
+ }
+#endif
+ }
+ if (ent->flags & (MON_AUTHDECIDE|MON_ALOG)) {
+ auth_log(ssh, authenticated, partial,
+ auth_method, auth_submethod);
+ if (!partial && !authenticated)
+ authctxt->failures++;
+ if (authenticated || partial) {
+ auth2_update_session_info(authctxt,
+ auth_method, auth_submethod);
+ }
+ }
+ }
+
+ if (!authctxt->valid)
+ fatal_f("authenticated invalid user");
+ if (strcmp(auth_method, "unknown") == 0)
+ fatal_f("authentication method name unknown");
+
+ debug_f("user %s authenticated by privileged process", authctxt->user);
+ ssh->authctxt = NULL;
+ ssh_packet_set_log_preamble(ssh, "user %s", authctxt->user);
+
+ mm_get_keystate(ssh, pmonitor);
+
+ /* Drain any buffered messages from the child */
+ while (pmonitor->m_log_recvfd != -1 && monitor_read_log(pmonitor) == 0)
+ ;
+
+ if (pmonitor->m_recvfd >= 0)
+ close(pmonitor->m_recvfd);
+ if (pmonitor->m_log_sendfd >= 0)
+ close(pmonitor->m_log_sendfd);
+ pmonitor->m_sendfd = pmonitor->m_log_recvfd = -1;
+}
+
+static void
+monitor_set_child_handler(pid_t pid)
+{
+ monitor_child_pid = pid;
+}
+
+static void
+monitor_child_handler(int sig)
+{
+ kill(monitor_child_pid, sig);
+}
+
+void
+monitor_child_postauth(struct ssh *ssh, struct monitor *pmonitor)
+{
+ close(pmonitor->m_recvfd);
+ pmonitor->m_recvfd = -1;
+
+ monitor_set_child_handler(pmonitor->m_pid);
+ ssh_signal(SIGHUP, &monitor_child_handler);
+ ssh_signal(SIGTERM, &monitor_child_handler);
+ ssh_signal(SIGINT, &monitor_child_handler);
+#ifdef SIGXFSZ
+ ssh_signal(SIGXFSZ, SIG_IGN);
+#endif
+
+ mon_dispatch = mon_dispatch_postauth20;
+
+ /* Permit requests for moduli and signatures */
+ monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
+ monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
+ monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
+
+ if (auth_opts->permit_pty_flag) {
+ monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1);
+ monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1);
+ }
+
+ for (;;)
+ monitor_read(ssh, pmonitor, mon_dispatch, NULL);
+}
+
+static int
+monitor_read_log(struct monitor *pmonitor)
+{
+ struct sshbuf *logmsg;
+ u_int len, level, forced;
+ char *msg;
+ u_char *p;
+ int r;
+
+ if ((logmsg = sshbuf_new()) == NULL)
+ fatal_f("sshbuf_new");
+
+ /* Read length */
+ if ((r = sshbuf_reserve(logmsg, 4, &p)) != 0)
+ fatal_fr(r, "reserve len");
+ if (atomicio(read, pmonitor->m_log_recvfd, p, 4) != 4) {
+ if (errno == EPIPE) {
+ sshbuf_free(logmsg);
+ debug_f("child log fd closed");
+ close(pmonitor->m_log_recvfd);
+ pmonitor->m_log_recvfd = -1;
+ return -1;
+ }
+ fatal_f("log fd read: %s", strerror(errno));
+ }
+ if ((r = sshbuf_get_u32(logmsg, &len)) != 0)
+ fatal_fr(r, "parse len");
+ if (len <= 4 || len > 8192)
+ fatal_f("invalid log message length %u", len);
+
+ /* Read severity, message */
+ sshbuf_reset(logmsg);
+ if ((r = sshbuf_reserve(logmsg, len, &p)) != 0)
+ fatal_fr(r, "reserve msg");
+ if (atomicio(read, pmonitor->m_log_recvfd, p, len) != len)
+ fatal_f("log fd read: %s", strerror(errno));
+ if ((r = sshbuf_get_u32(logmsg, &level)) != 0 ||
+ (r = sshbuf_get_u32(logmsg, &forced)) != 0 ||
+ (r = sshbuf_get_cstring(logmsg, &msg, NULL)) != 0)
+ fatal_fr(r, "parse");
+
+ /* Log it */
+ if (log_level_name(level) == NULL)
+ fatal_f("invalid log level %u (corrupted message?)", level);
+ sshlogdirect(level, forced, "%s [preauth]", msg);
+
+ sshbuf_free(logmsg);
+ free(msg);
+
+ return 0;
+}
+
+static int
+monitor_read(struct ssh *ssh, struct monitor *pmonitor, struct mon_table *ent,
+ struct mon_table **pent)
+{
+ struct sshbuf *m;
+ int r, ret;
+ u_char type;
+ struct pollfd pfd[2];
+
+ for (;;) {
+ memset(&pfd, 0, sizeof(pfd));
+ pfd[0].fd = pmonitor->m_sendfd;
+ pfd[0].events = POLLIN;
+ pfd[1].fd = pmonitor->m_log_recvfd;
+ pfd[1].events = pfd[1].fd == -1 ? 0 : POLLIN;
+ if (poll(pfd, pfd[1].fd == -1 ? 1 : 2, -1) == -1) {
+ if (errno == EINTR || errno == EAGAIN)
+ continue;
+ fatal_f("poll: %s", strerror(errno));
+ }
+ if (pfd[1].revents) {
+ /*
+ * Drain all log messages before processing next
+ * monitor request.
+ */
+ monitor_read_log(pmonitor);
+ continue;
+ }
+ if (pfd[0].revents)
+ break; /* Continues below */
+ }
+
+ if ((m = sshbuf_new()) == NULL)
+ fatal_f("sshbuf_new");
+
+ mm_request_receive(pmonitor->m_sendfd, m);
+ if ((r = sshbuf_get_u8(m, &type)) != 0)
+ fatal_fr(r, "parse type");
+
+ debug3_f("checking request %d", type);
+
+ while (ent->f != NULL) {
+ if (ent->type == type)
+ break;
+ ent++;
+ }
+
+ if (ent->f != NULL) {
+ if (!(ent->flags & MON_PERMIT))
+ fatal_f("unpermitted request %d", type);
+ ret = (*ent->f)(ssh, pmonitor->m_sendfd, m);
+ sshbuf_free(m);
+
+ /* The child may use this request only once, disable it */
+ if (ent->flags & MON_ONCE) {
+ debug2_f("%d used once, disabling now", type);
+ ent->flags &= ~MON_PERMIT;
+ }
+
+ if (pent != NULL)
+ *pent = ent;
+
+ return ret;
+ }
+
+ fatal_f("unsupported request: %d", type);
+
+ /* NOTREACHED */
+ return (-1);
+}
+
+/* allowed key state */
+static int
+monitor_allowed_key(const u_char *blob, u_int bloblen)
+{
+ /* make sure key is allowed */
+ if (key_blob == NULL || key_bloblen != bloblen ||
+ timingsafe_bcmp(key_blob, blob, key_bloblen))
+ return (0);
+ return (1);
+}
+
+static void
+monitor_reset_key_state(void)
+{
+ /* reset state */
+ free(key_blob);
+ free(hostbased_cuser);
+ free(hostbased_chost);
+ sshauthopt_free(key_opts);
+ key_blob = NULL;
+ key_bloblen = 0;
+ key_blobtype = MM_NOKEY;
+ key_opts = NULL;
+ hostbased_cuser = NULL;
+ hostbased_chost = NULL;
+}
+
+#ifdef WITH_OPENSSL
+int
+mm_answer_moduli(struct ssh *ssh, int sock, struct sshbuf *m)
+{
+ DH *dh;
+ const BIGNUM *dh_p, *dh_g;
+ int r;
+ u_int min, want, max;
+
+ if ((r = sshbuf_get_u32(m, &min)) != 0 ||
+ (r = sshbuf_get_u32(m, &want)) != 0 ||
+ (r = sshbuf_get_u32(m, &max)) != 0)
+ fatal_fr(r, "parse");
+
+ debug3_f("got parameters: %d %d %d", min, want, max);
+ /* We need to check here, too, in case the child got corrupted */
+ if (max < min || want < min || max < want)
+ fatal_f("bad parameters: %d %d %d", min, want, max);
+
+ sshbuf_reset(m);
+
+ dh = choose_dh(min, want, max);
+ if (dh == NULL) {
+ if ((r = sshbuf_put_u8(m, 0)) != 0)
+ fatal_fr(r, "assemble empty");
+ return (0);
+ } else {
+ /* Send first bignum */
+ DH_get0_pqg(dh, &dh_p, NULL, &dh_g);
+ if ((r = sshbuf_put_u8(m, 1)) != 0 ||
+ (r = sshbuf_put_bignum2(m, dh_p)) != 0 ||
+ (r = sshbuf_put_bignum2(m, dh_g)) != 0)
+ fatal_fr(r, "assemble");
+
+ DH_free(dh);
+ }
+ mm_request_send(sock, MONITOR_ANS_MODULI, m);
+ return (0);
+}
+#endif
+
+int
+mm_answer_sign(struct ssh *ssh, int sock, struct sshbuf *m)
+{
+ extern int auth_sock; /* XXX move to state struct? */
+ struct sshkey *key;
+ struct sshbuf *sigbuf = NULL;
+ u_char *p = NULL, *signature = NULL;
+ char *alg = NULL;
+ size_t datlen, siglen, alglen;
+ int r, is_proof = 0;
+ u_int keyid, compat;
+ const char proof_req[] = "hostkeys-prove-00@openssh.com";
+
+ debug3_f("entering");
+
+ if ((r = sshbuf_get_u32(m, &keyid)) != 0 ||
+ (r = sshbuf_get_string(m, &p, &datlen)) != 0 ||
+ (r = sshbuf_get_cstring(m, &alg, &alglen)) != 0 ||
+ (r = sshbuf_get_u32(m, &compat)) != 0)
+ fatal_fr(r, "parse");
+ if (keyid > INT_MAX)
+ fatal_f("invalid key ID");
+
+ /*
+ * Supported KEX types use SHA1 (20 bytes), SHA256 (32 bytes),
+ * SHA384 (48 bytes) and SHA512 (64 bytes).
+ *
+ * Otherwise, verify the signature request is for a hostkey
+ * proof.
+ *
+ * XXX perform similar check for KEX signature requests too?
+ * it's not trivial, since what is signed is the hash, rather
+ * than the full kex structure...
+ */
+ if (datlen != 20 && datlen != 32 && datlen != 48 && datlen != 64) {
+ /*
+ * Construct expected hostkey proof and compare it to what
+ * the client sent us.
+ */
+ if (session_id2_len == 0) /* hostkeys is never first */
+ fatal_f("bad data length: %zu", datlen);
+ if ((key = get_hostkey_public_by_index(keyid, ssh)) == NULL)
+ fatal_f("no hostkey for index %d", keyid);
+ if ((sigbuf = sshbuf_new()) == NULL)
+ fatal_f("sshbuf_new");
+ if ((r = sshbuf_put_cstring(sigbuf, proof_req)) != 0 ||
+ (r = sshbuf_put_string(sigbuf, session_id2,
+ session_id2_len)) != 0 ||
+ (r = sshkey_puts(key, sigbuf)) != 0)
+ fatal_fr(r, "assemble private key proof");
+ if (datlen != sshbuf_len(sigbuf) ||
+ memcmp(p, sshbuf_ptr(sigbuf), sshbuf_len(sigbuf)) != 0)
+ fatal_f("bad data length: %zu, hostkey proof len %zu",
+ datlen, sshbuf_len(sigbuf));
+ sshbuf_free(sigbuf);
+ is_proof = 1;
+ }
+
+ /* save session id, it will be passed on the first call */
+ if (session_id2_len == 0) {
+ session_id2_len = datlen;
+ session_id2 = xmalloc(session_id2_len);
+ memcpy(session_id2, p, session_id2_len);
+ }
+
+ if ((key = get_hostkey_by_index(keyid)) != NULL) {
+ if ((r = sshkey_sign(key, &signature, &siglen, p, datlen, alg,
+ options.sk_provider, NULL, compat)) != 0)
+ fatal_fr(r, "sign");
+ } else if ((key = get_hostkey_public_by_index(keyid, ssh)) != NULL &&
+ auth_sock > 0) {
+ if ((r = ssh_agent_sign(auth_sock, key, &signature, &siglen,
+ p, datlen, alg, compat)) != 0)
+ fatal_fr(r, "agent sign");
+ } else
+ fatal_f("no hostkey from index %d", keyid);
+
+ debug3_f("%s %s signature len=%zu", alg,
+ is_proof ? "hostkey proof" : "KEX", siglen);
+
+ sshbuf_reset(m);
+ if ((r = sshbuf_put_string(m, signature, siglen)) != 0)
+ fatal_fr(r, "assemble");
+
+ free(alg);
+ free(p);
+ free(signature);
+
+ mm_request_send(sock, MONITOR_ANS_SIGN, m);
+
+ /* Turn on permissions for getpwnam */
+ monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
+
+ return (0);
+}
+
+#define PUTPW(b, id) \
+ do { \
+ if ((r = sshbuf_put_string(b, \
+ &pwent->id, sizeof(pwent->id))) != 0) \
+ fatal_fr(r, "assemble %s", #id); \
+ } while (0)
+
+/* Retrieves the password entry and also checks if the user is permitted */
+int
+mm_answer_pwnamallow(struct ssh *ssh, int sock, struct sshbuf *m)
+{
+ struct passwd *pwent;
+ int r, allowed = 0;
+ u_int i;
+
+ debug3_f("entering");
+
+ if (authctxt->attempt++ != 0)
+ fatal_f("multiple attempts for getpwnam");
+
+ if ((r = sshbuf_get_cstring(m, &authctxt->user, NULL)) != 0)
+ fatal_fr(r, "parse");
+
+ pwent = getpwnamallow(ssh, authctxt->user);
+
+ setproctitle("%s [priv]", pwent ? authctxt->user : "unknown");
+
+ sshbuf_reset(m);
+
+ if (pwent == NULL) {
+ if ((r = sshbuf_put_u8(m, 0)) != 0)
+ fatal_fr(r, "assemble fakepw");
+ authctxt->pw = fakepw();
+ goto out;
+ }
+
+ allowed = 1;
+ authctxt->pw = pwent;
+ authctxt->valid = 1;
+
+ /* XXX send fake class/dir/shell, etc. */
+ if ((r = sshbuf_put_u8(m, 1)) != 0)
+ fatal_fr(r, "assemble ok");
+ PUTPW(m, pw_uid);
+ PUTPW(m, pw_gid);
+#ifdef HAVE_STRUCT_PASSWD_PW_CHANGE
+ PUTPW(m, pw_change);
+#endif
+#ifdef HAVE_STRUCT_PASSWD_PW_EXPIRE
+ PUTPW(m, pw_expire);
+#endif
+ if ((r = sshbuf_put_cstring(m, pwent->pw_name)) != 0 ||
+ (r = sshbuf_put_cstring(m, "*")) != 0 ||
+#ifdef HAVE_STRUCT_PASSWD_PW_GECOS
+ (r = sshbuf_put_cstring(m, pwent->pw_gecos)) != 0 ||
+#endif
+#ifdef HAVE_STRUCT_PASSWD_PW_CLASS
+ (r = sshbuf_put_cstring(m, pwent->pw_class)) != 0 ||
+#endif
+ (r = sshbuf_put_cstring(m, pwent->pw_dir)) != 0 ||
+ (r = sshbuf_put_cstring(m, pwent->pw_shell)) != 0)
+ fatal_fr(r, "assemble pw");
+
+ out:
+ ssh_packet_set_log_preamble(ssh, "%suser %s",
+ authctxt->valid ? "authenticating" : "invalid ", authctxt->user);
+ if ((r = sshbuf_put_string(m, &options, sizeof(options))) != 0)
+ fatal_fr(r, "assemble options");
+
+#define M_CP_STROPT(x) do { \
+ if (options.x != NULL && \
+ (r = sshbuf_put_cstring(m, options.x)) != 0) \
+ fatal_fr(r, "assemble %s", #x); \
+ } while (0)
+#define M_CP_STRARRAYOPT(x, nx) do { \
+ for (i = 0; i < options.nx; i++) { \
+ if ((r = sshbuf_put_cstring(m, options.x[i])) != 0) \
+ fatal_fr(r, "assemble %s", #x); \
+ } \
+ } while (0)
+ /* See comment in servconf.h */
+ COPY_MATCH_STRING_OPTS();
+#undef M_CP_STROPT
+#undef M_CP_STRARRAYOPT
+
+ /* Create valid auth method lists */
+ if (auth2_setup_methods_lists(authctxt) != 0) {
+ /*
+ * The monitor will continue long enough to let the child
+ * run to its packet_disconnect(), but it must not allow any
+ * authentication to succeed.
+ */
+ debug_f("no valid authentication method lists");
+ }
+
+ debug3_f("sending MONITOR_ANS_PWNAM: %d", allowed);
+ mm_request_send(sock, MONITOR_ANS_PWNAM, m);
+
+ /* Allow service/style information on the auth context */
+ monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1);
+ monitor_permit(mon_dispatch, MONITOR_REQ_AUTH2_READ_BANNER, 1);
+
+#ifdef USE_PAM
+ if (options.use_pam)
+ monitor_permit(mon_dispatch, MONITOR_REQ_PAM_START, 1);
+#endif
+
+ return (0);
+}
+
+int mm_answer_auth2_read_banner(struct ssh *ssh, int sock, struct sshbuf *m)
+{
+ char *banner;
+ int r;
+
+ sshbuf_reset(m);
+ banner = auth2_read_banner();
+ if ((r = sshbuf_put_cstring(m, banner != NULL ? banner : "")) != 0)
+ fatal_fr(r, "assemble");
+ mm_request_send(sock, MONITOR_ANS_AUTH2_READ_BANNER, m);
+ free(banner);
+
+ return (0);
+}
+
+int
+mm_answer_authserv(struct ssh *ssh, int sock, struct sshbuf *m)
+{
+ int r;
+
+ monitor_permit_authentications(1);
+
+ if ((r = sshbuf_get_cstring(m, &authctxt->service, NULL)) != 0 ||
+ (r = sshbuf_get_cstring(m, &authctxt->style, NULL)) != 0)
+ fatal_fr(r, "parse");
+ debug3_f("service=%s, style=%s", authctxt->service, authctxt->style);
+
+ if (strlen(authctxt->style) == 0) {
+ free(authctxt->style);
+ authctxt->style = NULL;
+ }
+
+ return (0);
+}
+
+/*
+ * Check that the key type appears in the supplied pattern list, ignoring
+ * mismatches in the signature algorithm. (Signature algorithm checks are
+ * performed in the unprivileged authentication code).
+ * Returns 1 on success, 0 otherwise.
+ */
+static int
+key_base_type_match(const char *method, const struct sshkey *key,
+ const char *list)
+{
+ char *s, *l, *ol = xstrdup(list);
+ int found = 0;
+
+ l = ol;
+ for ((s = strsep(&l, ",")); s && *s != '\0'; (s = strsep(&l, ","))) {
+ if (sshkey_type_from_name(s) == key->type) {
+ found = 1;
+ break;
+ }
+ }
+ if (!found) {
+ error("%s key type %s is not in permitted list %s", method,
+ sshkey_ssh_name(key), list);
+ }
+
+ free(ol);
+ return found;
+}
+
+int
+mm_answer_authpassword(struct ssh *ssh, int sock, struct sshbuf *m)
+{
+ static int call_count;
+ char *passwd;
+ int r, authenticated;
+ size_t plen;
+
+ if (!options.password_authentication)
+ fatal_f("password authentication not enabled");
+ if ((r = sshbuf_get_cstring(m, &passwd, &plen)) != 0)
+ fatal_fr(r, "parse");
+ /* Only authenticate if the context is valid */
+ authenticated = options.password_authentication &&
+ auth_password(ssh, passwd);
+ freezero(passwd, plen);
+
+ sshbuf_reset(m);
+ if ((r = sshbuf_put_u32(m, authenticated)) != 0)
+ fatal_fr(r, "assemble");
+#ifdef USE_PAM
+ if ((r = sshbuf_put_u32(m, sshpam_get_maxtries_reached())) != 0)
+ fatal_fr(r, "assemble PAM");
+#endif
+
+ debug3("%s: sending result %d", __func__, authenticated);
+ debug3_f("sending result %d", authenticated);
+ mm_request_send(sock, MONITOR_ANS_AUTHPASSWORD, m);
+
+ call_count++;
+ if (plen == 0 && call_count == 1)
+ auth_method = "none";
+ else
+ auth_method = "password";
+
+ /* Causes monitor loop to terminate if authenticated */
+ return (authenticated);
+}
+
+#ifdef BSD_AUTH
+int
+mm_answer_bsdauthquery(struct ssh *ssh, int sock, struct sshbuf *m)
+{
+ char *name, *infotxt;
+ u_int numprompts, *echo_on, success;
+ char **prompts;
+ int r;
+
+ if (!options.kbd_interactive_authentication)
+ fatal_f("kbd-int authentication not enabled");
+ success = bsdauth_query(authctxt, &name, &infotxt, &numprompts,
+ &prompts, &echo_on) < 0 ? 0 : 1;
+
+ sshbuf_reset(m);
+ if ((r = sshbuf_put_u32(m, success)) != 0)
+ fatal_fr(r, "assemble");
+ if (success) {
+ if ((r = sshbuf_put_cstring(m, prompts[0])) != 0)
+ fatal_fr(r, "assemble prompt");
+ }
+
+ debug3_f("sending challenge success: %u", success);
+ mm_request_send(sock, MONITOR_ANS_BSDAUTHQUERY, m);
+
+ if (success) {
+ free(name);
+ free(infotxt);
+ free(prompts);
+ free(echo_on);
+ }
+
+ return (0);
+}
+
+int
+mm_answer_bsdauthrespond(struct ssh *ssh, int sock, struct sshbuf *m)
+{
+ char *response;
+ int r, authok;
+
+ if (!options.kbd_interactive_authentication)
+ fatal_f("kbd-int authentication not enabled");
+ if (authctxt->as == NULL)
+ fatal_f("no bsd auth session");
+
+ if ((r = sshbuf_get_cstring(m, &response, NULL)) != 0)
+ fatal_fr(r, "parse");
+ authok = options.kbd_interactive_authentication &&
+ auth_userresponse(authctxt->as, response, 0);
+ authctxt->as = NULL;
+ debug3_f("<%s> = <%d>", response, authok);
+ free(response);
+
+ sshbuf_reset(m);
+ if ((r = sshbuf_put_u32(m, authok)) != 0)
+ fatal_fr(r, "assemble");
+
+ debug3_f("sending authenticated: %d", authok);
+ mm_request_send(sock, MONITOR_ANS_BSDAUTHRESPOND, m);
+
+ auth_method = "keyboard-interactive";
+ auth_submethod = "bsdauth";
+
+ return (authok != 0);
+}
+#endif
+
+#ifdef USE_PAM
+int
+mm_answer_pam_start(struct ssh *ssh, int sock, struct sshbuf *m)
+{
+ if (!options.use_pam)
+ fatal("UsePAM not set, but ended up in %s anyway", __func__);
+
+ start_pam(ssh);
+
+ monitor_permit(mon_dispatch, MONITOR_REQ_PAM_ACCOUNT, 1);
+ if (options.kbd_interactive_authentication)
+ monitor_permit(mon_dispatch, MONITOR_REQ_PAM_INIT_CTX, 1);
+
+ return (0);
+}
+
+int
+mm_answer_pam_account(struct ssh *ssh, int sock, struct sshbuf *m)
+{
+ u_int ret;
+ int r;
+
+ if (!options.use_pam)
+ fatal("%s: PAM not enabled", __func__);
+
+ ret = do_pam_account();
+
+ if ((r = sshbuf_put_u32(m, ret)) != 0 ||
+ (r = sshbuf_put_stringb(m, loginmsg)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+
+ mm_request_send(sock, MONITOR_ANS_PAM_ACCOUNT, m);
+
+ return (ret);
+}
+
+static void *sshpam_ctxt, *sshpam_authok;
+extern KbdintDevice sshpam_device;
+
+int
+mm_answer_pam_init_ctx(struct ssh *ssh, int sock, struct sshbuf *m)
+{
+ u_int ok = 0;
+ int r;
+
+ debug3("%s", __func__);
+ if (!options.kbd_interactive_authentication)
+ fatal("%s: kbd-int authentication not enabled", __func__);
+ if (sshpam_ctxt != NULL)
+ fatal("%s: already called", __func__);
+ sshpam_ctxt = (sshpam_device.init_ctx)(authctxt);
+ sshpam_authok = NULL;
+ sshbuf_reset(m);
+ if (sshpam_ctxt != NULL) {
+ monitor_permit(mon_dispatch, MONITOR_REQ_PAM_FREE_CTX, 1);
+ monitor_permit(mon_dispatch, MONITOR_REQ_PAM_QUERY, 1);
+ ok = 1;
+ }
+ if ((r = sshbuf_put_u32(m, ok)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+ mm_request_send(sock, MONITOR_ANS_PAM_INIT_CTX, m);
+ return (0);
+}
+
+int
+mm_answer_pam_query(struct ssh *ssh, int sock, struct sshbuf *m)
+{
+ char *name = NULL, *info = NULL, **prompts = NULL;
+ u_int i, num = 0, *echo_on = 0;
+ int r, ret;
+
+ debug3("%s", __func__);
+ sshpam_authok = NULL;
+ if (sshpam_ctxt == NULL)
+ fatal("%s: no context", __func__);
+ ret = (sshpam_device.query)(sshpam_ctxt, &name, &info,
+ &num, &prompts, &echo_on);
+ if (ret == 0 && num == 0)
+ sshpam_authok = sshpam_ctxt;
+ if (num > 1 || name == NULL || info == NULL)
+ fatal("sshpam_device.query failed");
+ monitor_permit(mon_dispatch, MONITOR_REQ_PAM_RESPOND, 1);
+ sshbuf_reset(m);
+ if ((r = sshbuf_put_u32(m, ret)) != 0 ||
+ (r = sshbuf_put_cstring(m, name)) != 0 ||
+ (r = sshbuf_put_cstring(m, info)) != 0 ||
+ (r = sshbuf_put_u32(m, sshpam_get_maxtries_reached())) != 0 ||
+ (r = sshbuf_put_u32(m, num)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+ free(name);
+ free(info);
+ for (i = 0; i < num; ++i) {
+ if ((r = sshbuf_put_cstring(m, prompts[i])) != 0 ||
+ (r = sshbuf_put_u32(m, echo_on[i])) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+ free(prompts[i]);
+ }
+ free(prompts);
+ free(echo_on);
+ auth_method = "keyboard-interactive";
+ auth_submethod = "pam";
+ mm_request_send(sock, MONITOR_ANS_PAM_QUERY, m);
+ return (0);
+}
+
+int
+mm_answer_pam_respond(struct ssh *ssh, int sock, struct sshbuf *m)
+{
+ char **resp;
+ u_int i, num;
+ int r, ret;
+
+ debug3("%s", __func__);
+ if (sshpam_ctxt == NULL)
+ fatal("%s: no context", __func__);
+ sshpam_authok = NULL;
+ if ((r = sshbuf_get_u32(m, &num)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+ if (num > 0) {
+ resp = xcalloc(num, sizeof(char *));
+ for (i = 0; i < num; ++i) {
+ if ((r = sshbuf_get_cstring(m, &(resp[i]), NULL)) != 0)
+ fatal("%s: buffer error: %s",
+ __func__, ssh_err(r));
+ }
+ ret = (sshpam_device.respond)(sshpam_ctxt, num, resp);
+ for (i = 0; i < num; ++i)
+ free(resp[i]);
+ free(resp);
+ } else {
+ ret = (sshpam_device.respond)(sshpam_ctxt, num, NULL);
+ }
+ sshbuf_reset(m);
+ if ((r = sshbuf_put_u32(m, ret)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+ mm_request_send(sock, MONITOR_ANS_PAM_RESPOND, m);
+ auth_method = "keyboard-interactive";
+ auth_submethod = "pam";
+ if (ret == 0)
+ sshpam_authok = sshpam_ctxt;
+ return (0);
+}
+
+int
+mm_answer_pam_free_ctx(struct ssh *ssh, int sock, struct sshbuf *m)
+{
+ int r = sshpam_authok != NULL && sshpam_authok == sshpam_ctxt;
+
+ debug3("%s", __func__);
+ if (sshpam_ctxt == NULL)
+ fatal("%s: no context", __func__);
+ (sshpam_device.free_ctx)(sshpam_ctxt);
+ sshpam_ctxt = sshpam_authok = NULL;
+ sshbuf_reset(m);
+ mm_request_send(sock, MONITOR_ANS_PAM_FREE_CTX, m);
+ /* Allow another attempt */
+ monitor_permit(mon_dispatch, MONITOR_REQ_PAM_INIT_CTX, 1);
+ auth_method = "keyboard-interactive";
+ auth_submethod = "pam";
+ return r;
+}
+#endif
+
+int
+mm_answer_keyallowed(struct ssh *ssh, int sock, struct sshbuf *m)
+{
+ struct sshkey *key = NULL;
+ char *cuser, *chost;
+ u_int pubkey_auth_attempt;
+ u_int type = 0;
+ int r, allowed = 0;
+ struct sshauthopt *opts = NULL;
+
+ debug3_f("entering");
+ if ((r = sshbuf_get_u32(m, &type)) != 0 ||
+ (r = sshbuf_get_cstring(m, &cuser, NULL)) != 0 ||
+ (r = sshbuf_get_cstring(m, &chost, NULL)) != 0 ||
+ (r = sshkey_froms(m, &key)) != 0 ||
+ (r = sshbuf_get_u32(m, &pubkey_auth_attempt)) != 0)
+ fatal_fr(r, "parse");
+
+ if (key != NULL && authctxt->valid) {
+ /* These should not make it past the privsep child */
+ if (sshkey_type_plain(key->type) == KEY_RSA &&
+ (ssh->compat & SSH_BUG_RSASIGMD5) != 0)
+ fatal_f("passed a SSH_BUG_RSASIGMD5 key");
+
+ switch (type) {
+ case MM_USERKEY:
+ auth_method = "publickey";
+ if (!options.pubkey_authentication)
+ break;
+ if (auth2_key_already_used(authctxt, key))
+ break;
+ if (!key_base_type_match(auth_method, key,
+ options.pubkey_accepted_algos))
+ break;
+ allowed = user_key_allowed(ssh, authctxt->pw, key,
+ pubkey_auth_attempt, &opts);
+ break;
+ case MM_HOSTKEY:
+ auth_method = "hostbased";
+ if (!options.hostbased_authentication)
+ break;
+ if (auth2_key_already_used(authctxt, key))
+ break;
+ if (!key_base_type_match(auth_method, key,
+ options.hostbased_accepted_algos))
+ break;
+ allowed = hostbased_key_allowed(ssh, authctxt->pw,
+ cuser, chost, key);
+ auth2_record_info(authctxt,
+ "client user \"%.100s\", client host \"%.100s\"",
+ cuser, chost);
+ break;
+ default:
+ fatal_f("unknown key type %u", type);
+ break;
+ }
+ }
+
+ debug3_f("%s authentication%s: %s key is %s", auth_method,
+ pubkey_auth_attempt ? "" : " test",
+ (key == NULL || !authctxt->valid) ? "invalid" : sshkey_type(key),
+ allowed ? "allowed" : "not allowed");
+
+ auth2_record_key(authctxt, 0, key);
+
+ /* clear temporarily storage (used by verify) */
+ monitor_reset_key_state();
+
+ if (allowed) {
+ /* Save temporarily for comparison in verify */
+ if ((r = sshkey_to_blob(key, &key_blob, &key_bloblen)) != 0)
+ fatal_fr(r, "sshkey_to_blob");
+ key_blobtype = type;
+ key_opts = opts;
+ hostbased_cuser = cuser;
+ hostbased_chost = chost;
+ } else {
+ /* Log failed attempt */
+ auth_log(ssh, 0, 0, auth_method, NULL);
+ free(cuser);
+ free(chost);
+ }
+ sshkey_free(key);
+
+ sshbuf_reset(m);
+ if ((r = sshbuf_put_u32(m, allowed)) != 0)
+ fatal_fr(r, "assemble");
+ if (opts != NULL && (r = sshauthopt_serialise(opts, m, 1)) != 0)
+ fatal_fr(r, "sshauthopt_serialise");
+ mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m);
+
+ if (!allowed)
+ sshauthopt_free(opts);
+
+ return (0);
+}
+
+static int
+monitor_valid_userblob(struct ssh *ssh, const u_char *data, u_int datalen)
+{
+ struct sshbuf *b;
+ struct sshkey *hostkey = NULL;
+ const u_char *p;
+ char *userstyle, *cp;
+ size_t len;
+ u_char type;
+ int hostbound = 0, r, fail = 0;
+
+ if ((b = sshbuf_from(data, datalen)) == NULL)
+ fatal_f("sshbuf_from");
+
+ if (ssh->compat & SSH_OLD_SESSIONID) {
+ p = sshbuf_ptr(b);
+ len = sshbuf_len(b);
+ if ((session_id2 == NULL) ||
+ (len < session_id2_len) ||
+ (timingsafe_bcmp(p, session_id2, session_id2_len) != 0))
+ fail++;
+ if ((r = sshbuf_consume(b, session_id2_len)) != 0)
+ fatal_fr(r, "consume");
+ } else {
+ if ((r = sshbuf_get_string_direct(b, &p, &len)) != 0)
+ fatal_fr(r, "parse sessionid");
+ if ((session_id2 == NULL) ||
+ (len != session_id2_len) ||
+ (timingsafe_bcmp(p, session_id2, session_id2_len) != 0))
+ fail++;
+ }
+ if ((r = sshbuf_get_u8(b, &type)) != 0)
+ fatal_fr(r, "parse type");
+ if (type != SSH2_MSG_USERAUTH_REQUEST)
+ fail++;
+ if ((r = sshbuf_get_cstring(b, &cp, NULL)) != 0)
+ fatal_fr(r, "parse userstyle");
+ xasprintf(&userstyle, "%s%s%s", authctxt->user,
+ authctxt->style ? ":" : "",
+ authctxt->style ? authctxt->style : "");
+ if (strcmp(userstyle, cp) != 0) {
+ logit("wrong user name passed to monitor: "
+ "expected %s != %.100s", userstyle, cp);
+ fail++;
+ }
+ free(userstyle);
+ free(cp);
+ if ((r = sshbuf_skip_string(b)) != 0 || /* service */
+ (r = sshbuf_get_cstring(b, &cp, NULL)) != 0)
+ fatal_fr(r, "parse method");
+ if (strcmp("publickey", cp) != 0) {
+ if (strcmp("publickey-hostbound-v00@openssh.com", cp) == 0)
+ hostbound = 1;
+ else
+ fail++;
+ }
+ free(cp);
+ if ((r = sshbuf_get_u8(b, &type)) != 0)
+ fatal_fr(r, "parse pktype");
+ if (type == 0)
+ fail++;
+ if ((r = sshbuf_skip_string(b)) != 0 || /* pkalg */
+ (r = sshbuf_skip_string(b)) != 0 || /* pkblob */
+ (hostbound && (r = sshkey_froms(b, &hostkey)) != 0))
+ fatal_fr(r, "parse pk");
+ if (sshbuf_len(b) != 0)
+ fail++;
+ sshbuf_free(b);
+ if (hostkey != NULL) {
+ /*
+ * Ensure this is actually one of our hostkeys; unfortunately
+ * can't check ssh->kex->initial_hostkey directly at this point
+ * as packet state has not yet been exported to monitor.
+ */
+ if (get_hostkey_index(hostkey, 1, ssh) == -1)
+ fatal_f("hostbound hostkey does not match");
+ sshkey_free(hostkey);
+ }
+ return (fail == 0);
+}
+
+static int
+monitor_valid_hostbasedblob(const u_char *data, u_int datalen,
+ const char *cuser, const char *chost)
+{
+ struct sshbuf *b;
+ const u_char *p;
+ char *cp, *userstyle;
+ size_t len;
+ int r, fail = 0;
+ u_char type;
+
+ if ((b = sshbuf_from(data, datalen)) == NULL)
+ fatal_f("sshbuf_new");
+ if ((r = sshbuf_get_string_direct(b, &p, &len)) != 0)
+ fatal_fr(r, "parse sessionid");
+
+ if ((session_id2 == NULL) ||
+ (len != session_id2_len) ||
+ (timingsafe_bcmp(p, session_id2, session_id2_len) != 0))
+ fail++;
+
+ if ((r = sshbuf_get_u8(b, &type)) != 0)
+ fatal_fr(r, "parse type");
+ if (type != SSH2_MSG_USERAUTH_REQUEST)
+ fail++;
+ if ((r = sshbuf_get_cstring(b, &cp, NULL)) != 0)
+ fatal_fr(r, "parse userstyle");
+ xasprintf(&userstyle, "%s%s%s", authctxt->user,
+ authctxt->style ? ":" : "",
+ authctxt->style ? authctxt->style : "");
+ if (strcmp(userstyle, cp) != 0) {
+ logit("wrong user name passed to monitor: "
+ "expected %s != %.100s", userstyle, cp);
+ fail++;
+ }
+ free(userstyle);
+ free(cp);
+ if ((r = sshbuf_skip_string(b)) != 0 || /* service */
+ (r = sshbuf_get_cstring(b, &cp, NULL)) != 0)
+ fatal_fr(r, "parse method");
+ if (strcmp(cp, "hostbased") != 0)
+ fail++;
+ free(cp);
+ if ((r = sshbuf_skip_string(b)) != 0 || /* pkalg */
+ (r = sshbuf_skip_string(b)) != 0) /* pkblob */
+ fatal_fr(r, "parse pk");
+
+ /* verify client host, strip trailing dot if necessary */
+ if ((r = sshbuf_get_cstring(b, &cp, NULL)) != 0)
+ fatal_fr(r, "parse host");
+ if (((len = strlen(cp)) > 0) && cp[len - 1] == '.')
+ cp[len - 1] = '\0';
+ if (strcmp(cp, chost) != 0)
+ fail++;
+ free(cp);
+
+ /* verify client user */
+ if ((r = sshbuf_get_cstring(b, &cp, NULL)) != 0)
+ fatal_fr(r, "parse ruser");
+ if (strcmp(cp, cuser) != 0)
+ fail++;
+ free(cp);
+
+ if (sshbuf_len(b) != 0)
+ fail++;
+ sshbuf_free(b);
+ return (fail == 0);
+}
+
+int
+mm_answer_keyverify(struct ssh *ssh, int sock, struct sshbuf *m)
+{
+ struct sshkey *key;
+ const u_char *signature, *data, *blob;
+ char *sigalg = NULL, *fp = NULL;
+ size_t signaturelen, datalen, bloblen;
+ int r, ret, req_presence = 0, req_verify = 0, valid_data = 0;
+ int encoded_ret;
+ struct sshkey_sig_details *sig_details = NULL;
+
+ if ((r = sshbuf_get_string_direct(m, &blob, &bloblen)) != 0 ||
+ (r = sshbuf_get_string_direct(m, &signature, &signaturelen)) != 0 ||
+ (r = sshbuf_get_string_direct(m, &data, &datalen)) != 0 ||
+ (r = sshbuf_get_cstring(m, &sigalg, NULL)) != 0)
+ fatal_fr(r, "parse");
+
+ if (hostbased_cuser == NULL || hostbased_chost == NULL ||
+ !monitor_allowed_key(blob, bloblen))
+ fatal_f("bad key, not previously allowed");
+
+ /* Empty signature algorithm means NULL. */
+ if (*sigalg == '\0') {
+ free(sigalg);
+ sigalg = NULL;
+ }
+
+ /* XXX use sshkey_froms here; need to change key_blob, etc. */
+ if ((r = sshkey_from_blob(blob, bloblen, &key)) != 0)
+ fatal_fr(r, "parse key");
+
+ switch (key_blobtype) {
+ case MM_USERKEY:
+ valid_data = monitor_valid_userblob(ssh, data, datalen);
+ auth_method = "publickey";
+ break;
+ case MM_HOSTKEY:
+ valid_data = monitor_valid_hostbasedblob(data, datalen,
+ hostbased_cuser, hostbased_chost);
+ auth_method = "hostbased";
+ break;
+ default:
+ valid_data = 0;
+ break;
+ }
+ if (!valid_data)
+ fatal_f("bad %s signature data blob",
+ key_blobtype == MM_USERKEY ? "userkey" :
+ (key_blobtype == MM_HOSTKEY ? "hostkey" : "unknown"));
+
+ if ((fp = sshkey_fingerprint(key, options.fingerprint_hash,
+ SSH_FP_DEFAULT)) == NULL)
+ fatal_f("sshkey_fingerprint failed");
+
+ ret = sshkey_verify(key, signature, signaturelen, data, datalen,
+ sigalg, ssh->compat, &sig_details);
+ debug3_f("%s %s signature using %s %s%s%s", auth_method,
+ sshkey_type(key), sigalg == NULL ? "default" : sigalg,
+ (ret == 0) ? "verified" : "unverified",
+ (ret != 0) ? ": " : "", (ret != 0) ? ssh_err(ret) : "");
+
+ if (ret == 0 && key_blobtype == MM_USERKEY && sig_details != NULL) {
+ req_presence = (options.pubkey_auth_options &
+ PUBKEYAUTH_TOUCH_REQUIRED) ||
+ !key_opts->no_require_user_presence;
+ if (req_presence &&
+ (sig_details->sk_flags & SSH_SK_USER_PRESENCE_REQD) == 0) {
+ error("public key %s %s signature for %s%s from %.128s "
+ "port %d rejected: user presence "
+ "(authenticator touch) requirement not met ",
+ sshkey_type(key), fp,
+ authctxt->valid ? "" : "invalid user ",
+ authctxt->user, ssh_remote_ipaddr(ssh),
+ ssh_remote_port(ssh));
+ ret = SSH_ERR_SIGNATURE_INVALID;
+ }
+ req_verify = (options.pubkey_auth_options &
+ PUBKEYAUTH_VERIFY_REQUIRED) || key_opts->require_verify;
+ if (req_verify &&
+ (sig_details->sk_flags & SSH_SK_USER_VERIFICATION_REQD) == 0) {
+ error("public key %s %s signature for %s%s from %.128s "
+ "port %d rejected: user verification requirement "
+ "not met ", sshkey_type(key), fp,
+ authctxt->valid ? "" : "invalid user ",
+ authctxt->user, ssh_remote_ipaddr(ssh),
+ ssh_remote_port(ssh));
+ ret = SSH_ERR_SIGNATURE_INVALID;
+ }
+ }
+ auth2_record_key(authctxt, ret == 0, key);
+
+ if (key_blobtype == MM_USERKEY)
+ auth_activate_options(ssh, key_opts);
+ monitor_reset_key_state();
+
+ sshbuf_reset(m);
+
+ /* encode ret != 0 as positive integer, since we're sending u32 */
+ encoded_ret = (ret != 0);
+ if ((r = sshbuf_put_u32(m, encoded_ret)) != 0 ||
+ (r = sshbuf_put_u8(m, sig_details != NULL)) != 0)
+ fatal_fr(r, "assemble");
+ if (sig_details != NULL) {
+ if ((r = sshbuf_put_u32(m, sig_details->sk_counter)) != 0 ||
+ (r = sshbuf_put_u8(m, sig_details->sk_flags)) != 0)
+ fatal_fr(r, "assemble sk");
+ }
+ sshkey_sig_details_free(sig_details);
+ mm_request_send(sock, MONITOR_ANS_KEYVERIFY, m);
+
+ free(sigalg);
+ free(fp);
+ sshkey_free(key);
+
+ return ret == 0;
+}
+
+static void
+mm_record_login(struct ssh *ssh, Session *s, struct passwd *pw)
+{
+ socklen_t fromlen;
+ struct sockaddr_storage from;
+
+ /*
+ * Get IP address of client. If the connection is not a socket, let
+ * the address be 0.0.0.0.
+ */
+ memset(&from, 0, sizeof(from));
+ fromlen = sizeof(from);
+ if (ssh_packet_connection_is_on_socket(ssh)) {
+ if (getpeername(ssh_packet_get_connection_in(ssh),
+ (struct sockaddr *)&from, &fromlen) == -1) {
+ debug("getpeername: %.100s", strerror(errno));
+ cleanup_exit(255);
+ }
+ }
+ /* Record that there was a login on that tty from the remote host. */
+ record_login(s->pid, s->tty, pw->pw_name, pw->pw_uid,
+ session_get_remote_name_or_ip(ssh, utmp_len, options.use_dns),
+ (struct sockaddr *)&from, fromlen);
+}
+
+static void
+mm_session_close(Session *s)
+{
+ debug3_f("session %d pid %ld", s->self, (long)s->pid);
+ if (s->ttyfd != -1) {
+ debug3_f("tty %s ptyfd %d", s->tty, s->ptyfd);
+ session_pty_cleanup2(s);
+ }
+ session_unused(s->self);
+}
+
+int
+mm_answer_pty(struct ssh *ssh, int sock, struct sshbuf *m)
+{
+ extern struct monitor *pmonitor;
+ Session *s;
+ int r, res, fd0;
+
+ debug3_f("entering");
+
+ sshbuf_reset(m);
+ s = session_new();
+ if (s == NULL)
+ goto error;
+ s->authctxt = authctxt;
+ s->pw = authctxt->pw;
+ s->pid = pmonitor->m_pid;
+ res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty));
+ if (res == 0)
+ goto error;
+ pty_setowner(authctxt->pw, s->tty);
+
+ if ((r = sshbuf_put_u32(m, 1)) != 0 ||
+ (r = sshbuf_put_cstring(m, s->tty)) != 0)
+ fatal_fr(r, "assemble");
+
+ /* We need to trick ttyslot */
+ if (dup2(s->ttyfd, 0) == -1)
+ fatal_f("dup2");
+
+ mm_record_login(ssh, s, authctxt->pw);
+
+ /* Now we can close the file descriptor again */
+ close(0);
+
+ /* send messages generated by record_login */
+ if ((r = sshbuf_put_stringb(m, loginmsg)) != 0)
+ fatal_fr(r, "assemble loginmsg");
+ sshbuf_reset(loginmsg);
+
+ mm_request_send(sock, MONITOR_ANS_PTY, m);
+
+ if (mm_send_fd(sock, s->ptyfd) == -1 ||
+ mm_send_fd(sock, s->ttyfd) == -1)
+ fatal_f("send fds failed");
+
+ /* make sure nothing uses fd 0 */
+ if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) == -1)
+ fatal_f("open(/dev/null): %s", strerror(errno));
+ if (fd0 != 0)
+ error_f("fd0 %d != 0", fd0);
+
+ /* slave side of pty is not needed */
+ close(s->ttyfd);
+ s->ttyfd = s->ptyfd;
+ /* no need to dup() because nobody closes ptyfd */
+ s->ptymaster = s->ptyfd;
+
+ debug3_f("tty %s ptyfd %d", s->tty, s->ttyfd);
+
+ return (0);
+
+ error:
+ if (s != NULL)
+ mm_session_close(s);
+ if ((r = sshbuf_put_u32(m, 0)) != 0)
+ fatal_fr(r, "assemble 0");
+ mm_request_send(sock, MONITOR_ANS_PTY, m);
+ return (0);
+}
+
+int
+mm_answer_pty_cleanup(struct ssh *ssh, int sock, struct sshbuf *m)
+{
+ Session *s;
+ char *tty;
+ int r;
+
+ debug3_f("entering");
+
+ if ((r = sshbuf_get_cstring(m, &tty, NULL)) != 0)
+ fatal_fr(r, "parse tty");
+ if ((s = session_by_tty(tty)) != NULL)
+ mm_session_close(s);
+ sshbuf_reset(m);
+ free(tty);
+ return (0);
+}
+
+int
+mm_answer_term(struct ssh *ssh, int sock, struct sshbuf *req)
+{
+ extern struct monitor *pmonitor;
+ int res, status;
+
+ debug3_f("tearing down sessions");
+
+ /* The child is terminating */
+ session_destroy_all(ssh, &mm_session_close);
+
+#ifdef USE_PAM
+ if (options.use_pam)
+ sshpam_cleanup();
+#endif
+
+ while (waitpid(pmonitor->m_pid, &status, 0) == -1)
+ if (errno != EINTR)
+ exit(1);
+
+ res = WIFEXITED(status) ? WEXITSTATUS(status) : 1;
+
+ /* Terminate process */
+ exit(res);
+}
+
+#ifdef SSH_AUDIT_EVENTS
+/* Report that an audit event occurred */
+int
+mm_answer_audit_event(struct ssh *ssh, int socket, struct sshbuf *m)
+{
+ u_int n;
+ ssh_audit_event_t event;
+ int r;
+
+ debug3("%s entering", __func__);
+
+ if ((r = sshbuf_get_u32(m, &n)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+ event = (ssh_audit_event_t)n;
+ switch (event) {
+ case SSH_AUTH_FAIL_PUBKEY:
+ case SSH_AUTH_FAIL_HOSTBASED:
+ case SSH_AUTH_FAIL_GSSAPI:
+ case SSH_LOGIN_EXCEED_MAXTRIES:
+ case SSH_LOGIN_ROOT_DENIED:
+ case SSH_CONNECTION_CLOSE:
+ case SSH_INVALID_USER:
+ audit_event(ssh, event);
+ break;
+ default:
+ fatal("Audit event type %d not permitted", event);
+ }
+
+ return (0);
+}
+
+int
+mm_answer_audit_command(struct ssh *ssh, int socket, struct sshbuf *m)
+{
+ char *cmd;
+ int r;
+
+ debug3("%s entering", __func__);
+ if ((r = sshbuf_get_cstring(m, &cmd, NULL)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+ /* sanity check command, if so how? */
+ audit_run_command(cmd);
+ free(cmd);
+ return (0);
+}
+#endif /* SSH_AUDIT_EVENTS */
+
+void
+monitor_clear_keystate(struct ssh *ssh, struct monitor *pmonitor)
+{
+ ssh_clear_newkeys(ssh, MODE_IN);
+ ssh_clear_newkeys(ssh, MODE_OUT);
+ sshbuf_free(child_state);
+ child_state = NULL;
+}
+
+void
+monitor_apply_keystate(struct ssh *ssh, struct monitor *pmonitor)
+{
+ struct kex *kex;
+ int r;
+
+ debug3_f("packet_set_state");
+ if ((r = ssh_packet_set_state(ssh, child_state)) != 0)
+ fatal_fr(r, "packet_set_state");
+ sshbuf_free(child_state);
+ child_state = NULL;
+ if ((kex = ssh->kex) == NULL)
+ fatal_f("internal error: ssh->kex == NULL");
+ if (session_id2_len != sshbuf_len(ssh->kex->session_id)) {
+ fatal_f("incorrect session id length %zu (expected %u)",
+ sshbuf_len(ssh->kex->session_id), session_id2_len);
+ }
+ if (memcmp(sshbuf_ptr(ssh->kex->session_id), session_id2,
+ session_id2_len) != 0)
+ fatal_f("session ID mismatch");
+ /* XXX set callbacks */
+#ifdef WITH_OPENSSL
+ 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] = kex_gen_server;
+# endif
+#endif /* WITH_OPENSSL */
+ kex->kex[KEX_C25519_SHA256] = kex_gen_server;
+ kex->kex[KEX_KEM_SNTRUP761X25519_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;
+}
+
+/* This function requires careful sanity checking */
+
+void
+mm_get_keystate(struct ssh *ssh, struct monitor *pmonitor)
+{
+ debug3_f("Waiting for new keys");
+
+ if ((child_state = sshbuf_new()) == NULL)
+ fatal_f("sshbuf_new failed");
+ mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT,
+ child_state);
+ debug3_f("GOT new keys");
+}
+
+
+/* XXX */
+
+#define FD_CLOSEONEXEC(x) do { \
+ if (fcntl(x, F_SETFD, FD_CLOEXEC) == -1) \
+ fatal("fcntl(%d, F_SETFD)", x); \
+} while (0)
+
+static void
+monitor_openfds(struct monitor *mon, int do_logfds)
+{
+ int pair[2];
+#ifdef SO_ZEROIZE
+ int on = 1;
+#endif
+
+ if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1)
+ fatal_f("socketpair: %s", strerror(errno));
+#ifdef SO_ZEROIZE
+ if (setsockopt(pair[0], SOL_SOCKET, SO_ZEROIZE, &on, sizeof(on)) == -1)
+ error("setsockopt SO_ZEROIZE(0): %.100s", strerror(errno));
+ if (setsockopt(pair[1], SOL_SOCKET, SO_ZEROIZE, &on, sizeof(on)) == -1)
+ error("setsockopt SO_ZEROIZE(1): %.100s", strerror(errno));
+#endif
+ FD_CLOSEONEXEC(pair[0]);
+ FD_CLOSEONEXEC(pair[1]);
+ mon->m_recvfd = pair[0];
+ mon->m_sendfd = pair[1];
+
+ if (do_logfds) {
+ if (pipe(pair) == -1)
+ fatal_f("pipe: %s", strerror(errno));
+ FD_CLOSEONEXEC(pair[0]);
+ FD_CLOSEONEXEC(pair[1]);
+ mon->m_log_recvfd = pair[0];
+ mon->m_log_sendfd = pair[1];
+ } else
+ mon->m_log_recvfd = mon->m_log_sendfd = -1;
+}
+
+#define MM_MEMSIZE 65536
+
+struct monitor *
+monitor_init(void)
+{
+ struct monitor *mon;
+
+ mon = xcalloc(1, sizeof(*mon));
+ monitor_openfds(mon, 1);
+
+ return mon;
+}
+
+void
+monitor_reinit(struct monitor *mon)
+{
+ monitor_openfds(mon, 0);
+}
+
+#ifdef GSSAPI
+int
+mm_answer_gss_setup_ctx(struct ssh *ssh, int sock, struct sshbuf *m)
+{
+ gss_OID_desc goid;
+ OM_uint32 major;
+ size_t len;
+ u_char *p;
+ int r;
+
+ if (!options.gss_authentication)
+ fatal_f("GSSAPI authentication not enabled");
+
+ if ((r = sshbuf_get_string(m, &p, &len)) != 0)
+ fatal_fr(r, "parse");
+ goid.elements = p;
+ goid.length = len;
+
+ major = ssh_gssapi_server_ctx(&gsscontext, &goid);
+
+ free(goid.elements);
+
+ sshbuf_reset(m);
+ if ((r = sshbuf_put_u32(m, major)) != 0)
+ fatal_fr(r, "assemble");
+
+ mm_request_send(sock, MONITOR_ANS_GSSSETUP, m);
+
+ /* Now we have a context, enable the step */
+ monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1);
+
+ return (0);
+}
+
+int
+mm_answer_gss_accept_ctx(struct ssh *ssh, int sock, struct sshbuf *m)
+{
+ gss_buffer_desc in;
+ gss_buffer_desc out = GSS_C_EMPTY_BUFFER;
+ OM_uint32 major, minor;
+ OM_uint32 flags = 0; /* GSI needs this */
+ int r;
+
+ if (!options.gss_authentication)
+ fatal_f("GSSAPI authentication not enabled");
+
+ if ((r = ssh_gssapi_get_buffer_desc(m, &in)) != 0)
+ fatal_fr(r, "ssh_gssapi_get_buffer_desc");
+ major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags);
+ free(in.value);
+
+ sshbuf_reset(m);
+ if ((r = sshbuf_put_u32(m, major)) != 0 ||
+ (r = sshbuf_put_string(m, out.value, out.length)) != 0 ||
+ (r = sshbuf_put_u32(m, flags)) != 0)
+ fatal_fr(r, "assemble");
+ mm_request_send(sock, MONITOR_ANS_GSSSTEP, m);
+
+ gss_release_buffer(&minor, &out);
+
+ if (major == GSS_S_COMPLETE) {
+ monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0);
+ monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
+ monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1);
+ }
+ return (0);
+}
+
+int
+mm_answer_gss_checkmic(struct ssh *ssh, int sock, struct sshbuf *m)
+{
+ gss_buffer_desc gssbuf, mic;
+ OM_uint32 ret;
+ int r;
+
+ if (!options.gss_authentication)
+ fatal_f("GSSAPI authentication not enabled");
+
+ if ((r = ssh_gssapi_get_buffer_desc(m, &gssbuf)) != 0 ||
+ (r = ssh_gssapi_get_buffer_desc(m, &mic)) != 0)
+ fatal_fr(r, "ssh_gssapi_get_buffer_desc");
+
+ ret = ssh_gssapi_checkmic(gsscontext, &gssbuf, &mic);
+
+ free(gssbuf.value);
+ free(mic.value);
+
+ sshbuf_reset(m);
+ if ((r = sshbuf_put_u32(m, ret)) != 0)
+ fatal_fr(r, "assemble");
+
+ mm_request_send(sock, MONITOR_ANS_GSSCHECKMIC, m);
+
+ if (!GSS_ERROR(ret))
+ monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
+
+ return (0);
+}
+
+int
+mm_answer_gss_userok(struct ssh *ssh, int sock, struct sshbuf *m)
+{
+ int r, authenticated;
+ const char *displayname;
+
+ if (!options.gss_authentication)
+ fatal_f("GSSAPI authentication not enabled");
+
+ authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user);
+
+ sshbuf_reset(m);
+ if ((r = sshbuf_put_u32(m, authenticated)) != 0)
+ fatal_fr(r, "assemble");
+
+ debug3_f("sending result %d", authenticated);
+ mm_request_send(sock, MONITOR_ANS_GSSUSEROK, m);
+
+ auth_method = "gssapi-with-mic";
+
+ if ((displayname = ssh_gssapi_displayname()) != NULL)
+ auth2_record_info(authctxt, "%s", displayname);
+
+ /* Monitor loop will terminate if authenticated */
+ return (authenticated);
+}
+#endif /* GSSAPI */
+