- provos@cvs.openbsd.org 2002/03/18 17:50:31

     [auth-bsdauth.c auth-options.c auth-rh-rsa.c auth-rsa.c auth-skey.c auth.h
      auth1.c auth2-chall.c auth2.c kex.c kex.h kexdh.c kexgex.c servconf.c
      session.h servconf.h serverloop.c session.c sshd.c]
     integrate privilege separated openssh; its turned off by default for now.
     work done by me and markus@

applied, but outside of ensure that smaller code bits migrated with
their owners.. no work was tried to 'fix' it to work. =)  Later project!

1 files changed, 1440 insertions, 0 deletions

diff --git a/monitor.c b/monitor.c
new file mode 100644
index 00000000..921ad985
--- /dev/null
+++ b/monitor.c
@@ -0,0 +1,1440 @@
+/*
+ * 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"
+RCSID("$OpenBSD: monitor.c,v 1.6 2002/03/21 18:38:33 stevesk Exp $");
+
+#include <openssl/dh.h>
+
+#ifdef SKEY
+#include <skey.h>
+#endif
+
+#include "ssh.h"
+#include "auth.h"
+#include "kex.h"
+#include "dh.h"
+#include "zlib.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 "servconf.h"
+#include "monitor.h"
+#include "monitor_mm.h"
+#include "monitor_wrap.h"
+#include "monitor_fdpass.h"
+#include "xmalloc.h"
+#include "misc.h"
+#include "buffer.h"
+#include "bufaux.h"
+#include "compat.h"
+#include "ssh2.h"
+#include "mpaux.h"
+
+/* Imports */
+extern ServerOptions options;
+extern u_int utmp_len;
+extern Newkeys *current_keys[];
+extern z_stream incoming_stream;
+extern z_stream outgoing_stream;
+extern u_char session_id[];
+extern Buffer input, output;
+extern Buffer auth_debug;
+extern int auth_debug_init;
+
+/* State exported from the child */
+
+struct {
+	z_stream incoming;
+	z_stream outgoing;
+	u_char *keyin;
+	u_int keyinlen;
+	u_char *keyout;
+	u_int keyoutlen;
+	u_char *ivin;
+	u_int ivinlen;
+	u_char *ivout;
+	u_int ivoutlen;
+	int ssh1cipher;
+	int ssh1protoflags;
+	u_char *input;
+	u_int ilen;
+	u_char *output;
+	u_int olen;
+} child_state;
+
+/* Functions on the montior that answer unprivileged requests */
+
+int mm_answer_moduli(int, Buffer *);
+int mm_answer_sign(int, Buffer *);
+int mm_answer_pwnamallow(int, Buffer *);
+int mm_answer_authserv(int, Buffer *);
+int mm_answer_authpassword(int, Buffer *);
+int mm_answer_bsdauthquery(int, Buffer *);
+int mm_answer_bsdauthrespond(int, Buffer *);
+int mm_answer_skeyquery(int, Buffer *);
+int mm_answer_skeyrespond(int, Buffer *);
+int mm_answer_keyallowed(int, Buffer *);
+int mm_answer_keyverify(int, Buffer *);
+int mm_answer_pty(int, Buffer *);
+int mm_answer_pty_cleanup(int, Buffer *);
+int mm_answer_term(int, Buffer *);
+int mm_answer_rsa_keyallowed(int, Buffer *);
+int mm_answer_rsa_challenge(int, Buffer *);
+int mm_answer_rsa_response(int, Buffer *);
+int mm_answer_sesskey(int, Buffer *);
+int mm_answer_sessid(int, Buffer *);
+
+static Authctxt *authctxt;
+static BIGNUM *ssh1_challenge = NULL;	/* used for ssh1 rsa auth */
+
+/* local state for key verify */
+static u_char *key_blob = NULL;
+static u_int key_bloblen = 0;
+static int key_blobtype = MM_NOKEY;
+static u_char *hostbased_cuser = NULL;
+static u_char *hostbased_chost = NULL;
+static char *auth_method = "unknown";
+
+struct mon_table {
+	enum monitor_reqtype type;
+	int flags;
+	int (*f)(int, Buffer *);
+};
+
+#define MON_ISAUTH	0x0004	/* Required for Authentication */
+#define MON_AUTHDECIDE	0x0008	/* Decides Authentication */
+#define MON_ONCE	0x0010	/* Disable after calling */
+
+#define MON_AUTH	(MON_ISAUTH|MON_AUTHDECIDE)
+
+#define MON_PERMIT	0x1000	/* Request is permitted */
+
+struct mon_table mon_dispatch_proto20[] = {
+    {MONITOR_REQ_MODULI, MON_ONCE, mm_answer_moduli},
+    {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_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
+#ifdef BSD_AUTH
+    {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
+    {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH,mm_answer_bsdauthrespond},
+#endif
+#ifdef SKEY
+    {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
+    {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
+#endif
+    {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed},
+    {MONITOR_REQ_KEYVERIFY, MON_AUTH, mm_answer_keyverify},
+    {0, 0, NULL}
+};
+
+struct mon_table mon_dispatch_postauth20[] = {
+    {MONITOR_REQ_MODULI, 0, mm_answer_moduli},
+    {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},
+    {0, 0, NULL}
+};
+
+struct mon_table mon_dispatch_proto15[] = {
+    {MONITOR_REQ_PWNAM, MON_ONCE, mm_answer_pwnamallow},
+    {MONITOR_REQ_SESSKEY, MON_ONCE, mm_answer_sesskey},
+    {MONITOR_REQ_SESSID, MON_ONCE, mm_answer_sessid},
+    {MONITOR_REQ_AUTHPASSWORD, MON_AUTH, mm_answer_authpassword},
+    {MONITOR_REQ_RSAKEYALLOWED, MON_ISAUTH, mm_answer_rsa_keyallowed},
+    {MONITOR_REQ_KEYALLOWED, MON_ISAUTH, mm_answer_keyallowed},
+    {MONITOR_REQ_RSACHALLENGE, MON_ONCE, mm_answer_rsa_challenge},
+    {MONITOR_REQ_RSARESPONSE, MON_ONCE|MON_AUTHDECIDE, mm_answer_rsa_response},
+#ifdef BSD_AUTH
+    {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery},
+    {MONITOR_REQ_BSDAUTHRESPOND, MON_AUTH,mm_answer_bsdauthrespond},
+#endif
+#ifdef SKEY
+    {MONITOR_REQ_SKEYQUERY, MON_ISAUTH, mm_answer_skeyquery},
+    {MONITOR_REQ_SKEYRESPOND, MON_AUTH, mm_answer_skeyrespond},
+#endif
+    {0, 0, NULL}
+};
+
+struct mon_table mon_dispatch_postauth15[] = {
+    {MONITOR_REQ_PTY, MON_ONCE, mm_answer_pty},
+    {MONITOR_REQ_PTYCLEANUP, MON_ONCE, mm_answer_pty_cleanup},
+    {MONITOR_REQ_TERM, 0, mm_answer_term},
+    {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++;
+	}
+}
+
+Authctxt *
+monitor_child_preauth(struct monitor *monitor)
+{
+	struct mon_table *ent;
+	int authenticated = 0;
+
+	debug3("preauth child monitor started");
+
+	if (compat20) {
+		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);
+	} else {
+		mon_dispatch = mon_dispatch_proto15;
+
+		monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1);
+	}
+
+	authctxt = authctxt_new();
+
+	/* The first few requests do not require asynchronous access */
+	while (!authenticated) {
+		authenticated = monitor_read(monitor, mon_dispatch, &ent);
+		if (authenticated) {
+			if (!(ent->flags & MON_AUTHDECIDE))
+				fatal("%s: unexpected authentication from %d",
+				    __FUNCTION__, ent->type);
+			if (authctxt->pw->pw_uid == 0 &&
+			    !auth_root_allowed(auth_method))
+				authenticated = 0;
+		}
+
+		if (ent->flags & MON_AUTHDECIDE) {
+			auth_log(authctxt, authenticated, auth_method,
+			    compat20 ? " ssh2" : "");
+			if (!authenticated)
+				authctxt->failures++;
+		}
+	}
+
+	if (!authctxt->valid)
+		fatal("%s: authenticated invalid user", __FUNCTION__);
+
+	debug("%s: %s has been authenticated by privileged process",
+	    __FUNCTION__, authctxt->user);
+
+	mm_get_keystate(monitor);
+
+	return (authctxt);
+}
+
+void
+monitor_child_postauth(struct monitor *monitor)
+{
+	if (compat20) {
+		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);
+
+	} else {
+		mon_dispatch = mon_dispatch_postauth15;
+		monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
+	}
+	if (!no_pty_flag) {
+		monitor_permit(mon_dispatch, MONITOR_REQ_PTY, 1);
+		monitor_permit(mon_dispatch, MONITOR_REQ_PTYCLEANUP, 1);
+	}
+
+	for (;;)
+		monitor_read(monitor, mon_dispatch, NULL);
+}
+
+void
+monitor_sync(struct monitor *monitor)
+{
+	/* The member allocation is not visible, so sync it */
+	mm_share_sync(&monitor->m_zlib, &monitor->m_zback);
+}
+
+int
+monitor_read(struct monitor *monitor, struct mon_table *ent,
+    struct mon_table **pent)
+{
+	Buffer m;
+	int ret;
+	u_char type;
+
+	buffer_init(&m);
+
+	mm_request_receive(monitor->m_sendfd, &m);
+	type = buffer_get_char(&m);
+
+	debug3("%s: checking request %d", __FUNCTION__, type);
+
+	while (ent->f != NULL) {
+		if (ent->type == type)
+			break;
+		ent++;
+	}
+
+	if (ent->f != NULL) {
+		if (!(ent->flags & MON_PERMIT))
+			fatal("%s: unpermitted request %d", __FUNCTION__,
+			    type);
+		ret = (*ent->f)(monitor->m_sendfd, &m);
+		buffer_free(&m);
+
+		/* The child may use this request only once, disable it */
+		if (ent->flags & MON_ONCE) {
+			debug2("%s: %d used once, disabling now", __FUNCTION__,
+			    type);
+			ent->flags &= ~MON_PERMIT;
+		}
+
+		if (pent != NULL)
+			*pent = ent;
+
+		return ret;
+	}
+
+	fatal("%s: unsupported request: %d\n", __FUNCTION__, type);
+
+	/* NOTREACHED */
+	return (-1);
+}
+
+/* allowed key state */
+static int
+monitor_allowed_key(u_char *blob, u_int bloblen)
+{
+	/* make sure key is allowed */
+	if (key_blob == NULL || key_bloblen != bloblen ||
+	    memcmp(key_blob, blob, key_bloblen))
+		return (0);
+	return (1);
+}
+
+static void
+monitor_reset_key_state(void)
+{
+	/* reset state */
+	if (key_blob != NULL)
+		xfree(key_blob);
+	if (hostbased_cuser != NULL)
+		xfree(hostbased_cuser);
+	if (hostbased_chost != NULL)
+		xfree(hostbased_chost);
+	key_blob = NULL;
+	key_bloblen = 0;
+	key_blobtype = MM_NOKEY;
+	hostbased_cuser = NULL;
+	hostbased_chost = NULL;
+}
+
+int
+mm_answer_moduli(int socket, Buffer *m)
+{
+	DH *dh;
+	int min, want, max;
+
+	min = buffer_get_int(m);
+	want = buffer_get_int(m);
+	max = buffer_get_int(m);
+
+	debug3("%s: got parameters: %d %d %d",
+	    __FUNCTION__, min, want, max);
+	/* We need to check here, too, in case the child got corrupted */
+	if (max < min || want < min || max < want)
+		fatal("%s: bad parameters: %d %d %d",
+		    __FUNCTION__, min, want, max);
+
+	buffer_clear(m);
+
+	dh = choose_dh(min, want, max);
+	if (dh == NULL) {
+		buffer_put_char(m, 0);
+		return (0);
+	} else {
+		/* Send first bignum */
+		buffer_put_char(m, 1);
+		buffer_put_bignum2(m, dh->p);
+		buffer_put_bignum2(m, dh->g);
+
+		DH_free(dh);
+	}
+	mm_request_send(socket, MONITOR_ANS_MODULI, m);
+	return (0);
+}
+
+int
+mm_answer_sign(int socket, Buffer *m)
+{
+	Key *key;
+	u_char *p;
+	u_char *signature;
+	u_int siglen, datlen;
+	int keyid;
+
+	debug3("%s", __FUNCTION__);
+
+	keyid = buffer_get_int(m);
+	p = buffer_get_string(m, &datlen);
+
+	if (datlen != 20)
+		fatal("%s: data length incorrect: %d", __FUNCTION__, datlen);
+
+	if ((key = get_hostkey_by_index(keyid)) == NULL)
+		fatal("%s: no hostkey from index %d", __FUNCTION__, keyid);
+	if (key_sign(key, &signature, &siglen, p, datlen) < 0)
+		fatal("%s: key_sign failed", __FUNCTION__);
+
+	debug3("%s: signature %p(%d)", __FUNCTION__, signature, siglen);
+
+	buffer_clear(m);
+	buffer_put_string(m, signature, siglen);
+
+	xfree(p);
+	xfree(signature);
+
+	mm_request_send(socket, MONITOR_ANS_SIGN, m);
+
+	/* Turn on permissions for getpwnam */
+	monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
+
+	return (0);
+}
+
+/* Retrieves the password entry and also checks if the user is permitted */
+
+int
+mm_answer_pwnamallow(int socket, Buffer *m)
+{
+	char *login;
+	struct passwd *pwent;
+	int allowed = 0;
+
+	debug3("%s", __FUNCTION__);
+
+	if (authctxt->attempt++ != 0)
+		fatal("%s: multiple attempts for getpwnam", __FUNCTION__);
+
+	login = buffer_get_string(m, NULL);
+
+	pwent = getpwnamallow(login);
+
+	authctxt->user = xstrdup(login);
+	setproctitle("%s [priv]", pwent ? login : "unknown");
+	xfree(login);
+
+	buffer_clear(m);
+
+	if (pwent == NULL) {
+		buffer_put_char(m, 0);
+		goto out;
+	}
+
+	allowed = 1;
+	authctxt->pw = pwent;
+	authctxt->valid = 1;
+
+	buffer_put_char(m, 1);
+	buffer_put_string(m, pwent, sizeof(struct passwd));
+	buffer_put_cstring(m, pwent->pw_name);
+	buffer_put_cstring(m, "*");
+	buffer_put_cstring(m, pwent->pw_gecos);
+	buffer_put_cstring(m, pwent->pw_class);
+	buffer_put_cstring(m, pwent->pw_dir);
+	buffer_put_cstring(m, pwent->pw_shell);
+
+ out:
+	debug3("%s: sending MONITOR_ANS_PWNAM: %d", __FUNCTION__, allowed);
+	mm_request_send(socket, MONITOR_ANS_PWNAM, m);
+
+	/* For SSHv1 allow authentication now */
+	if (!compat20)
+		monitor_permit_authentications(1);
+	else
+		/* Allow service/style information on the auth context */
+		monitor_permit(mon_dispatch, MONITOR_REQ_AUTHSERV, 1);
+
+
+	return (0);
+}
+
+int
+mm_answer_authserv(int socket, Buffer *m)
+{
+	monitor_permit_authentications(1);
+
+	authctxt->service = buffer_get_string(m, NULL);
+	authctxt->style = buffer_get_string(m, NULL);
+	debug3("%s: service=%s, style=%s",
+	    __FUNCTION__, authctxt->service, authctxt->style);
+
+	if (strlen(authctxt->style) == 0) {
+		xfree(authctxt->style);
+		authctxt->style = NULL;
+	}
+
+	return (0);
+}
+
+int
+mm_answer_authpassword(int socket, Buffer *m)
+{
+	static int call_count;
+	char *passwd;
+	int authenticated, plen;
+
+	passwd = buffer_get_string(m, &plen);
+	/* Only authenticate if the context is valid */
+	authenticated = authctxt->valid && auth_password(authctxt, passwd);
+	memset(passwd, 0, strlen(passwd));
+	xfree(passwd);
+
+	buffer_clear(m);
+	buffer_put_int(m, authenticated);
+
+	debug3("%s: sending result %d", __FUNCTION__, authenticated);
+	mm_request_send(socket, 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(int socket, Buffer *m)
+{
+	char *name, *infotxt;
+	u_int numprompts;
+	u_int *echo_on;
+	char **prompts;
+	int res;
+
+	res = bsdauth_query(authctxt, &name, &infotxt, &numprompts,
+	    &prompts, &echo_on);
+
+	buffer_clear(m);
+	buffer_put_int(m, res);
+	if (res != -1)
+		buffer_put_cstring(m, prompts[0]);
+
+	debug3("%s: sending challenge res: %d", __FUNCTION__, res);
+	mm_request_send(socket, MONITOR_ANS_BSDAUTHQUERY, m);
+
+	if (res != -1) {
+		xfree(name);
+		xfree(infotxt);
+		xfree(prompts);
+		xfree(echo_on);
+	}
+
+	return (0);
+}
+
+int
+mm_answer_bsdauthrespond(int socket, Buffer *m)
+{
+	char *response;
+	int authok;
+
+	if (authctxt->as == 0)
+		fatal("%s: no bsd auth session", __FUNCTION__);
+
+	response = buffer_get_string(m, NULL);
+	authok = auth_userresponse(authctxt->as, response, 0);
+	authctxt->as = NULL;
+	debug3("%s: <%s> = <%d>", __FUNCTION__, response, authok);
+	xfree(response);
+
+	buffer_clear(m);
+	buffer_put_int(m, authok);
+
+	debug3("%s: sending authenticated: %d", __FUNCTION__, authok);
+	mm_request_send(socket, MONITOR_ANS_BSDAUTHRESPOND, m);
+
+	auth_method = "bsdauth";
+
+	return (authok != 0);
+}
+#endif
+
+#ifdef SKEY
+int
+mm_answer_skeyquery(int socket, Buffer *m)
+{
+	struct skey skey;
+	char challenge[1024];
+	int res;
+
+	res = skeychallenge(&skey, authctxt->user, challenge);
+
+	buffer_clear(m);
+	buffer_put_int(m, res);
+	if (res != -1)
+		buffer_put_cstring(m, challenge);
+
+	debug3("%s: sending challenge res: %d", __FUNCTION__, res);
+	mm_request_send(socket, MONITOR_ANS_SKEYQUERY, m);
+
+	return (0);
+}
+
+int
+mm_answer_skeyrespond(int socket, Buffer *m)
+{
+	char *response;
+	int authok;
+
+	response = buffer_get_string(m, NULL);
+
+	authok = (authctxt->valid &&
+	    skey_haskey(authctxt->pw->pw_name) == 0 &&
+	    skey_passcheck(authctxt->pw->pw_name, response) != -1);
+
+	xfree(response);
+
+	buffer_clear(m);
+	buffer_put_int(m, authok);
+
+	debug3("%s: sending authenticated: %d", __FUNCTION__, authok);
+	mm_request_send(socket, MONITOR_ANS_SKEYRESPOND, m);
+
+	auth_method = "skey";
+
+	return (authok != 0);
+}
+#endif
+
+static void
+mm_append_debug(Buffer *m)
+{
+	if (auth_debug_init && buffer_len(&auth_debug)) {
+		debug3("%s: Appending debug messages for child", __FUNCTION__);
+		buffer_append(m, buffer_ptr(&auth_debug),
+		    buffer_len(&auth_debug));
+		buffer_clear(&auth_debug);
+	}
+}
+
+int
+mm_answer_keyallowed(int socket, Buffer *m)
+{
+	Key *key;
+	u_char *cuser, *chost, *blob;
+	u_int bloblen;
+	enum mm_keytype type = 0;
+	int allowed = 0;
+
+	debug3("%s entering", __FUNCTION__);
+
+	type = buffer_get_int(m);
+	cuser = buffer_get_string(m, NULL);
+	chost = buffer_get_string(m, NULL);
+	blob = buffer_get_string(m, &bloblen);
+
+	key = key_from_blob(blob, bloblen);
+
+	if ((compat20 && type == MM_RSAHOSTKEY) ||
+	    (!compat20 && type != MM_RSAHOSTKEY))
+		fatal("%s: key type and protocol mismatch", __FUNCTION__);
+
+	debug3("%s: key_from_blob: %p", __FUNCTION__, key);
+
+	if (key != NULL && authctxt->pw != NULL) {
+		switch(type) {
+		case MM_USERKEY:
+			allowed = user_key_allowed(authctxt->pw, key);
+			break;
+		case MM_HOSTKEY:
+			allowed = hostbased_key_allowed(authctxt->pw,
+			    cuser, chost, key);
+			break;
+		case MM_RSAHOSTKEY:
+			key->type = KEY_RSA1; /* XXX */
+			allowed = auth_rhosts_rsa_key_allowed(authctxt->pw,
+			    cuser, chost, key);
+			break;
+		default:
+			fatal("%s: unknown key type %d", __FUNCTION__, type);
+			break;
+		}
+		key_free(key);
+	}
+
+	/* clear temporarily storage (used by verify) */
+	monitor_reset_key_state();
+
+	if (allowed) {
+		/* Save temporarily for comparison in verify */
+		key_blob = blob;
+		key_bloblen = bloblen;
+		key_blobtype = type;
+		hostbased_cuser = cuser;
+		hostbased_chost = chost;
+	}
+
+	debug3("%s: key %p is %s",
+	    __FUNCTION__, key, allowed ? "allowed" : "disallowed");
+
+	buffer_clear(m);
+	buffer_put_int(m, allowed);
+
+	mm_append_debug(m);
+
+	mm_request_send(socket, MONITOR_ANS_KEYALLOWED, m);
+
+	if (type == MM_RSAHOSTKEY)
+		monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
+
+	return (0);
+}
+
+static int
+monitor_valid_userblob(u_char *data, u_int datalen)
+{
+	Buffer b;
+	u_char *p;
+	u_int len;
+	int fail = 0;
+	int session_id2_len = 20 /*XXX should get from [net] */;
+
+	buffer_init(&b);
+	buffer_append(&b, data, datalen);
+
+	if (datafellows & SSH_OLD_SESSIONID) {
+		buffer_consume(&b, session_id2_len);
+	} else {
+		xfree(buffer_get_string(&b, &len));
+		if (len != session_id2_len)
+			fail++;
+	}
+	if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
+		fail++;
+	p = buffer_get_string(&b, NULL);
+	if (strcmp(authctxt->user, p) != 0) {
+		log("wrong user name passed to monitor: expected %s != %.100s",
+		    authctxt->user, p);
+		fail++;
+	}
+	xfree(p);
+	buffer_skip_string(&b);
+	if (datafellows & SSH_BUG_PKAUTH) {
+		if (!buffer_get_char(&b))
+			fail++;
+	} else {
+		p = buffer_get_string(&b, NULL);
+		if (strcmp("publickey", p) != 0)
+			fail++;
+		xfree(p);
+		if (!buffer_get_char(&b))
+			fail++;
+		buffer_skip_string(&b);
+	}
+	buffer_skip_string(&b);
+	if (buffer_len(&b) != 0)
+		fail++;
+	buffer_free(&b);
+	return (fail == 0);
+}
+
+static int
+monitor_valid_hostbasedblob(u_char *data, u_int datalen, u_char *cuser,
+    u_char *chost)
+{
+	Buffer b;
+	u_char *p;
+	u_int len;
+	int fail = 0;
+	int session_id2_len = 20 /*XXX should get from [net] */;
+
+	buffer_init(&b);
+	buffer_append(&b, data, datalen);
+
+	xfree(buffer_get_string(&b, &len));
+	if (len != session_id2_len)
+		fail++;
+	if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
+		fail++;
+	p = buffer_get_string(&b, NULL);
+	if (strcmp(authctxt->user, p) != 0) {
+		log("wrong user name passed to monitor: expected %s != %.100s",
+		    authctxt->user, p);
+		fail++;
+	}
+	xfree(p);
+	buffer_skip_string(&b);	/* service */
+	p = buffer_get_string(&b, NULL);
+	if (strcmp(p, "hostbased") != 0)
+		fail++;
+	xfree(p);
+	buffer_skip_string(&b);	/* pkalg */
+	buffer_skip_string(&b);	/* pkblob */
+
+	/* verify client host, strip trailing dot if necessary */
+	p = buffer_get_string(&b, NULL);
+	if (((len = strlen(p)) > 0) && p[len - 1] == '.')
+		p[len - 1] = '\0';
+	if (strcmp(p, chost) != 0)
+		fail++;
+	xfree(p);
+
+	/* verify client user */
+	p = buffer_get_string(&b, NULL);
+	if (strcmp(p, cuser) != 0)
+		fail++;
+	xfree(p);
+
+	if (buffer_len(&b) != 0)
+		fail++;
+	buffer_free(&b);
+	return (fail == 0);
+}
+
+int
+mm_answer_keyverify(int socket, Buffer *m)
+{
+	Key *key;
+	u_char *signature, *data, *blob;
+	u_int signaturelen, datalen, bloblen;
+	int verified = 0;
+	int valid_data = 0;
+
+	blob = buffer_get_string(m, &bloblen);
+	signature = buffer_get_string(m, &signaturelen);
+	data = buffer_get_string(m, &datalen);
+
+	if (hostbased_cuser == NULL || hostbased_chost == NULL ||
+	   monitor_allowed_key(blob, bloblen) == NULL)
+		fatal("%s: bad key, not previously allowed", __FUNCTION__);
+
+	key = key_from_blob(blob, bloblen);
+	if (key == NULL)
+		fatal("%s: bad public key blob", __FUNCTION__);
+
+	switch (key_blobtype) {
+	case MM_USERKEY:
+		valid_data = monitor_valid_userblob(data, datalen);
+		break;
+	case MM_HOSTKEY:
+		valid_data = monitor_valid_hostbasedblob(data, datalen,
+		    hostbased_cuser, hostbased_chost);
+		break;
+	default:
+		valid_data = 0;
+		break;
+	}
+	if (!valid_data)
+		fatal("%s: bad signature data blob", __FUNCTION__);
+
+	verified = key_verify(key, signature, signaturelen, data, datalen);
+	debug3("%s: key %p signature %s",
+	    __FUNCTION__, key, verified ? "verified" : "unverified");
+
+	key_free(key);
+	xfree(blob);
+	xfree(signature);
+	xfree(data);
+
+	monitor_reset_key_state();
+
+	buffer_clear(m);
+	buffer_put_int(m, verified);
+	mm_request_send(socket, MONITOR_ANS_KEYVERIFY, m);
+
+	auth_method = "publickey";
+
+	return (verified);
+}
+
+static void
+mm_record_login(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));
+	if (packet_connection_is_on_socket()) {
+		fromlen = sizeof(from);
+		if (getpeername(packet_get_connection_in(),
+			(struct sockaddr *) & from, &fromlen) < 0) {
+			debug("getpeername: %.100s", strerror(errno));
+			fatal_cleanup();
+		}
+	}
+	/* 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,
+	    get_remote_name_or_ip(utmp_len, options.verify_reverse_mapping),
+	    (struct sockaddr *)&from);
+}
+
+static void
+mm_session_close(Session *s)
+{
+	debug3("%s: session %d pid %d", __FUNCTION__, s->self, s->pid);
+	if (s->ttyfd != -1) {
+		debug3("%s: tty %s ptyfd %d",  __FUNCTION__, s->tty, s->ptyfd);
+		fatal_remove_cleanup(session_pty_cleanup2, (void *)s);
+		session_pty_cleanup2(s);
+	}
+	s->used = 0;
+}
+
+int
+mm_answer_pty(int socket, Buffer *m)
+{
+	extern struct monitor *monitor;
+	Session *s;
+	int res, fd0;
+
+	debug3("%s entering", __FUNCTION__);
+
+	buffer_clear(m);
+	s = session_new();
+	if (s == NULL)
+		goto error;
+	s->authctxt = authctxt;
+	s->pw = authctxt->pw;
+	s->pid = monitor->m_pid;
+	res = pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty));
+	if (res == 0)
+		goto error;
+	fatal_add_cleanup(session_pty_cleanup2, (void *)s);
+	pty_setowner(authctxt->pw, s->tty);
+
+	buffer_put_int(m, 1);
+	buffer_put_cstring(m, s->tty);
+	mm_request_send(socket, MONITOR_ANS_PTY, m);
+
+	mm_send_fd(socket, s->ptyfd);
+	mm_send_fd(socket, s->ttyfd);
+
+	/* We need to trick ttyslot */
+	if (dup2(s->ttyfd, 0) == -1)
+		fatal("%s: dup2", __FUNCTION__);
+
+	mm_record_login(s, authctxt->pw);
+
+	/* Now we can close the file descriptor again */
+	close(0);
+
+	/* make sure nothing uses fd 0 */
+	if ((fd0 = open(_PATH_DEVNULL, O_RDONLY)) < 0)
+		fatal("%s: open(/dev/null): %s", __FUNCTION__, strerror(errno));
+	if (fd0 != 0)
+		error("%s: fd0 %d != 0", __FUNCTION__, fd0);
+
+	/* slave is not needed */
+	close(s->ttyfd);
+	s->ttyfd = s->ptyfd;
+	/* no need to dup() because nobody closes ptyfd */
+	s->ptymaster = s->ptyfd;
+
+	debug3("%s: tty %s ptyfd %d",  __FUNCTION__, s->tty, s->ttyfd);
+
+	return (0);
+
+ error:
+	if (s != NULL)
+		mm_session_close(s);
+	buffer_put_int(m, 0);
+	mm_request_send(socket, MONITOR_ANS_PTY, m);
+	return (0);
+}
+
+int
+mm_answer_pty_cleanup(int socket, Buffer *m)
+{
+	Session *s;
+	char *tty;
+
+	debug3("%s entering", __FUNCTION__);
+
+	tty = buffer_get_string(m, NULL);
+	if ((s = session_by_tty(tty)) != NULL)
+		mm_session_close(s);
+	buffer_clear(m);
+	xfree(tty);
+	return (0);
+}
+
+int
+mm_answer_sesskey(int socket, Buffer *m)
+{
+	BIGNUM *p;
+	int rsafail;
+
+	/* Turn off permissions */
+	monitor_permit(mon_dispatch, MONITOR_REQ_SESSKEY, 1);
+
+	if ((p = BN_new()) == NULL)
+		fatal("%s: BN_new", __FUNCTION__);
+
+	buffer_get_bignum2(m, p);
+
+	rsafail = ssh1_session_key(p);
+
+	buffer_clear(m);
+	buffer_put_int(m, rsafail);
+	buffer_put_bignum2(m, p);
+
+	BN_clear_free(p);
+
+	mm_request_send(socket, MONITOR_ANS_SESSKEY, m);
+
+	/* Turn on permissions for sessid passing */
+	monitor_permit(mon_dispatch, MONITOR_REQ_SESSID, 1);
+
+	return (0);
+}
+
+int
+mm_answer_sessid(int socket, Buffer *m)
+{
+	int i;
+
+	debug3("%s entering", __FUNCTION__);
+
+	if (buffer_len(m) != 16)
+		fatal("%s: bad ssh1 session id", __FUNCTION__);
+	for (i = 0; i < 16; i++)
+		session_id[i] = buffer_get_char(m);
+
+	/* Turn on permissions for getpwnam */
+	monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
+
+	return (0);
+}
+
+int
+mm_answer_rsa_keyallowed(int socket, Buffer *m)
+{
+	BIGNUM *client_n;
+	Key *key = NULL;
+	u_char *blob = NULL;
+	u_int blen = 0;
+	int allowed = 0;
+
+	debug3("%s entering", __FUNCTION__);
+
+	if (authctxt->valid) {
+		if ((client_n = BN_new()) == NULL)
+			fatal("%s: BN_new", __FUNCTION__);
+		buffer_get_bignum2(m, client_n);
+		allowed = auth_rsa_key_allowed(authctxt->pw, client_n, &key);
+		BN_clear_free(client_n);
+	}
+	buffer_clear(m);
+	buffer_put_int(m, allowed);
+
+	/* clear temporarily storage (used by generate challenge) */
+	monitor_reset_key_state();
+
+	if (allowed && key != NULL) {
+		key->type = KEY_RSA;	/* cheat for key_to_blob */
+		if (key_to_blob(key, &blob, &blen) == 0)
+			fatal("%s: key_to_blob failed", __FUNCTION__);
+		buffer_put_string(m, blob, blen);
+
+		/* Save temporarily for comparison in verify */
+		key_blob = blob;
+		key_bloblen = blen;
+		key_blobtype = MM_RSAUSERKEY;
+		key_free(key);
+	}
+
+	mm_append_debug(m);
+
+	mm_request_send(socket, MONITOR_ANS_RSAKEYALLOWED, m);
+
+	monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
+	monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 0);
+	return (0);
+}
+
+int
+mm_answer_rsa_challenge(int socket, Buffer *m)
+{
+	Key *key = NULL;
+	u_char *blob;
+	u_int blen;
+
+	debug3("%s entering", __FUNCTION__);
+
+	if (!authctxt->valid)
+		fatal("%s: authctxt not valid", __FUNCTION__);
+	blob = buffer_get_string(m, &blen);
+	if (!monitor_allowed_key(blob, blen))
+		fatal("%s: bad key, not previously allowed", __FUNCTION__);
+	if (key_blobtype != MM_RSAUSERKEY && key_blobtype != MM_RSAHOSTKEY)
+		fatal("%s: key type mismatch", __FUNCTION__);
+	if ((key = key_from_blob(blob, blen)) == NULL)
+		fatal("%s: received bad key", __FUNCTION__);
+
+	if (ssh1_challenge)
+		BN_clear_free(ssh1_challenge);
+	ssh1_challenge = auth_rsa_generate_challenge(key);
+
+	buffer_clear(m);
+	buffer_put_bignum2(m, ssh1_challenge);
+
+	debug3("%s sending reply", __FUNCTION__);
+	mm_request_send(socket, MONITOR_ANS_RSACHALLENGE, m);
+
+	monitor_permit(mon_dispatch, MONITOR_REQ_RSARESPONSE, 1);
+	return (0);
+}
+
+int
+mm_answer_rsa_response(int socket, Buffer *m)
+{
+	Key *key = NULL;
+	u_char *blob, *response;
+	u_int blen, len;
+	int success;
+
+	debug3("%s entering", __FUNCTION__);
+
+	if (!authctxt->valid)
+		fatal("%s: authctxt not valid", __FUNCTION__);
+	if (ssh1_challenge == NULL)
+		fatal("%s: no ssh1_challenge", __FUNCTION__);
+
+	blob = buffer_get_string(m, &blen);
+	if (!monitor_allowed_key(blob, blen))
+		fatal("%s: bad key, not previously allowed", __FUNCTION__);