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GCC Code Coverage Report

Directory:	./		Exec	Total	Coverage
File:	usr.bin/ssh/sshd/../monitor_wrap.c	Lines:	0	265	0.0 %
Date:	2017-11-07	Branches:	0	108	0.0 %


/* $OpenBSD: monitor_wrap.c,v 1.94 2017/10/02 19:33:20 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 <sys/types.h>
#include <sys/uio.h>
#include <sys/queue.h>

#include <errno.h>
#include <pwd.h>
#include <signal.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>

#ifdef WITH_OPENSSL
#include <openssl/bn.h>
#include <openssl/dh.h>
#endif

#include "xmalloc.h"
#include "ssh.h"
#ifdef WITH_OPENSSL
#include "dh.h"
#endif
#include "buffer.h"
#include "key.h"
#include "cipher.h"
#include "kex.h"
#include "hostfile.h"
#include "auth.h"
#include "auth-options.h"
#include "packet.h"
#include "mac.h"
#include "log.h"
#include <zlib.h>
#include "monitor.h"
#ifdef GSSAPI
#include "ssh-gss.h"
#endif
#include "monitor_wrap.h"
#include "atomicio.h"
#include "monitor_fdpass.h"
#include "misc.h"
#include "uuencode.h"

#include "channels.h"
#include "session.h"
#include "servconf.h"

#include "ssherr.h"

/* Imports */
extern z_stream incoming_stream;
extern z_stream outgoing_stream;
extern struct monitor *pmonitor;
extern Buffer loginmsg;
extern ServerOptions options;

void
mm_log_handler(LogLevel level, const char *msg, void *ctx)
{
	Buffer log_msg;
	struct monitor *mon = (struct monitor *)ctx;

	if (mon->m_log_sendfd == -1)
		fatal("%s: no log channel", __func__);

	buffer_init(&log_msg);
	/*
	 * Placeholder for packet length. Will be filled in with the actual
	 * packet length once the packet has been constucted. This saves
	 * fragile math.
	 */
	buffer_put_int(&log_msg, 0);

	buffer_put_int(&log_msg, level);
	buffer_put_cstring(&log_msg, msg);
	put_u32(buffer_ptr(&log_msg), buffer_len(&log_msg) - 4);
	if (atomicio(vwrite, mon->m_log_sendfd, buffer_ptr(&log_msg),
	    buffer_len(&log_msg)) != buffer_len(&log_msg))
		fatal("%s: write: %s", __func__, strerror(errno));
	buffer_free(&log_msg);
}

int
mm_is_monitor(void)
{
	/*
	 * m_pid is only set in the privileged part, and
	 * points to the unprivileged child.
	 */
	return (pmonitor && pmonitor->m_pid > 0);
}

void
mm_request_send(int sock, enum monitor_reqtype type, Buffer *m)
{
	u_int mlen = buffer_len(m);
	u_char buf[5];

	debug3("%s entering: type %d", __func__, type);

	put_u32(buf, mlen + 1);
	buf[4] = (u_char) type;		/* 1st byte of payload is mesg-type */
	if (atomicio(vwrite, sock, buf, sizeof(buf)) != sizeof(buf))
		fatal("%s: write: %s", __func__, strerror(errno));
	if (atomicio(vwrite, sock, buffer_ptr(m), mlen) != mlen)
		fatal("%s: write: %s", __func__, strerror(errno));
}

void
mm_request_receive(int sock, Buffer *m)
{
	u_char buf[4];
	u_int msg_len;

	debug3("%s entering", __func__);

	if (atomicio(read, sock, buf, sizeof(buf)) != sizeof(buf)) {
		if (errno == EPIPE)
			cleanup_exit(255);
		fatal("%s: read: %s", __func__, strerror(errno));
	}
	msg_len = get_u32(buf);
	if (msg_len > 256 * 1024)
		fatal("%s: read: bad msg_len %d", __func__, msg_len);
	buffer_clear(m);
	buffer_append_space(m, msg_len);
	if (atomicio(read, sock, buffer_ptr(m), msg_len) != msg_len)
		fatal("%s: read: %s", __func__, strerror(errno));
}

void
mm_request_receive_expect(int sock, enum monitor_reqtype type, Buffer *m)
{
	u_char rtype;

	debug3("%s entering: type %d", __func__, type);

	mm_request_receive(sock, m);
	rtype = buffer_get_char(m);
	if (rtype != type)
		fatal("%s: read: rtype %d != type %d", __func__,
		    rtype, type);
}

#ifdef WITH_OPENSSL
DH *
mm_choose_dh(int min, int nbits, int max)
{
	BIGNUM *p, *g;
	int success = 0;
	Buffer m;

	buffer_init(&m);
	buffer_put_int(&m, min);
	buffer_put_int(&m, nbits);
	buffer_put_int(&m, max);

	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_MODULI, &m);

	debug3("%s: waiting for MONITOR_ANS_MODULI", __func__);
	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_MODULI, &m);

	success = buffer_get_char(&m);
	if (success == 0)
		fatal("%s: MONITOR_ANS_MODULI failed", __func__);

	if ((p = BN_new()) == NULL)
		fatal("%s: BN_new failed", __func__);
	if ((g = BN_new()) == NULL)
		fatal("%s: BN_new failed", __func__);
	buffer_get_bignum2(&m, p);
	buffer_get_bignum2(&m, g);

	debug3("%s: remaining %d", __func__, buffer_len(&m));
	buffer_free(&m);

	return (dh_new_group(g, p));
}
#endif

int
mm_key_sign(struct sshkey *key, u_char **sigp, u_int *lenp,
    const u_char *data, u_int datalen, const char *hostkey_alg)
{
	struct kex *kex = *pmonitor->m_pkex;
	Buffer m;

	debug3("%s entering", __func__);

	buffer_init(&m);
	buffer_put_int(&m, kex->host_key_index(key, 0, active_state));
	buffer_put_string(&m, data, datalen);
	buffer_put_cstring(&m, hostkey_alg);

	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SIGN, &m);

	debug3("%s: waiting for MONITOR_ANS_SIGN", __func__);
	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_SIGN, &m);
	*sigp  = buffer_get_string(&m, lenp);
	buffer_free(&m);

	return (0);
}

struct passwd *
mm_getpwnamallow(const char *username)
{
	struct ssh *ssh = active_state;		/* XXX */
	Buffer m;
	struct passwd *pw;
	u_int len, i;
	ServerOptions *newopts;

	debug3("%s entering", __func__);

	buffer_init(&m);
	buffer_put_cstring(&m, username);

	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PWNAM, &m);

	debug3("%s: waiting for MONITOR_ANS_PWNAM", __func__);
	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PWNAM, &m);

	if (buffer_get_char(&m) == 0) {
		pw = NULL;
		goto out;
	}
	pw = buffer_get_string(&m, &len);
	if (len != sizeof(struct passwd))
		fatal("%s: struct passwd size mismatch", __func__);
	pw->pw_name = buffer_get_string(&m, NULL);
	pw->pw_passwd = buffer_get_string(&m, NULL);
	pw->pw_gecos = buffer_get_string(&m, NULL);
	pw->pw_class = buffer_get_string(&m, NULL);
	pw->pw_dir = buffer_get_string(&m, NULL);
	pw->pw_shell = buffer_get_string(&m, NULL);

out:
	/* copy options block as a Match directive may have changed some */
	newopts = buffer_get_string(&m, &len);
	if (len != sizeof(*newopts))
		fatal("%s: option block size mismatch", __func__);

#define M_CP_STROPT(x) do { \
		if (newopts->x != NULL) \
			newopts->x = buffer_get_string(&m, NULL); \
	} while (0)
#define M_CP_STRARRAYOPT(x, nx) do { \
		for (i = 0; i < newopts->nx; i++) \
			newopts->x[i] = buffer_get_string(&m, NULL); \
	} while (0)
#define M_CP_STRARRAYOPT_ALLOC(x, nx) do { \
		newopts->x = newopts->nx == 0 ? \
		    NULL : xcalloc(newopts->nx, sizeof(*newopts->x)); \
		M_CP_STRARRAYOPT(x, nx); \
	} while (0)
	/* See comment in servconf.h */
	COPY_MATCH_STRING_OPTS();
#undef M_CP_STROPT
#undef M_CP_STRARRAYOPT
#undef M_CP_STRARRAYOPT_ALLOC

	copy_set_server_options(&options, newopts, 1);
	log_change_level(options.log_level);
	process_permitopen(ssh, &options);
	free(newopts);

	buffer_free(&m);

	return (pw);
}

char *
mm_auth2_read_banner(void)
{
	Buffer m;
	char *banner;

	debug3("%s entering", __func__);

	buffer_init(&m);
	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTH2_READ_BANNER, &m);
	buffer_clear(&m);

	mm_request_receive_expect(pmonitor->m_recvfd,
	    MONITOR_ANS_AUTH2_READ_BANNER, &m);
	banner = buffer_get_string(&m, NULL);
	buffer_free(&m);

	/* treat empty banner as missing banner */
	if (strlen(banner) == 0) {
		free(banner);
		banner = NULL;
	}
	return (banner);
}

/* Inform the privileged process about service and style */

void
mm_inform_authserv(char *service, char *style)
{
	Buffer m;

	debug3("%s entering", __func__);

	buffer_init(&m);
	buffer_put_cstring(&m, service);
	buffer_put_cstring(&m, style ? style : "");

	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHSERV, &m);

	buffer_free(&m);
}

/* Do the password authentication */
int
mm_auth_password(Authctxt *authctxt, char *password)
{
	Buffer m;
	int authenticated = 0;

	debug3("%s entering", __func__);

	buffer_init(&m);
	buffer_put_cstring(&m, password);
	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHPASSWORD, &m);

	debug3("%s: waiting for MONITOR_ANS_AUTHPASSWORD", __func__);
	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_AUTHPASSWORD, &m);

	authenticated = buffer_get_int(&m);

	buffer_free(&m);

	debug3("%s: user %sauthenticated",
	    __func__, authenticated ? "" : "not ");
	return (authenticated);
}

int
mm_user_key_allowed(struct passwd *pw, struct sshkey *key,
    int pubkey_auth_attempt)
{
	return (mm_key_allowed(MM_USERKEY, NULL, NULL, key,
	    pubkey_auth_attempt));
}

int
mm_hostbased_key_allowed(struct passwd *pw, const char *user, const char *host,
    struct sshkey *key)
{
	return (mm_key_allowed(MM_HOSTKEY, user, host, key, 0));
}

int
mm_key_allowed(enum mm_keytype type, const char *user, const char *host,
    struct sshkey *key, int pubkey_auth_attempt)
{
	Buffer m;
	u_char *blob;
	u_int len;
	int allowed = 0, have_forced = 0;

	debug3("%s entering", __func__);

	/* Convert the key to a blob and the pass it over */
	if (!key_to_blob(key, &blob, &len))
		return (0);

	buffer_init(&m);
	buffer_put_int(&m, type);
	buffer_put_cstring(&m, user ? user : "");
	buffer_put_cstring(&m, host ? host : "");
	buffer_put_string(&m, blob, len);
	buffer_put_int(&m, pubkey_auth_attempt);
	free(blob);

	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYALLOWED, &m);

	debug3("%s: waiting for MONITOR_ANS_KEYALLOWED", __func__);
	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_KEYALLOWED, &m);

	allowed = buffer_get_int(&m);

	/* fake forced command */
	auth_clear_options();
	have_forced = buffer_get_int(&m);
	forced_command = have_forced ? xstrdup("true") : NULL;

	buffer_free(&m);

	return (allowed);
}

/*
 * This key verify needs to send the key type along, because the
 * privileged parent makes the decision if the key is allowed
 * for authentication.
 */

int
mm_sshkey_verify(const struct sshkey *key, const u_char *sig, size_t siglen,
    const u_char *data, size_t datalen, u_int compat)
{
	Buffer m;
	u_char *blob;
	u_int len;
	u_int encoded_ret = 0;

	debug3("%s entering", __func__);

	/* Convert the key to a blob and the pass it over */
	if (!key_to_blob(key, &blob, &len))
		return (0);

	buffer_init(&m);
	buffer_put_string(&m, blob, len);
	buffer_put_string(&m, sig, siglen);
	buffer_put_string(&m, data, datalen);
	free(blob);

	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYVERIFY, &m);

	debug3("%s: waiting for MONITOR_ANS_KEYVERIFY", __func__);
	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_KEYVERIFY, &m);

	encoded_ret = buffer_get_int(&m);

	buffer_free(&m);

	if (encoded_ret != 0)
		return SSH_ERR_SIGNATURE_INVALID;
	return 0;
}

void
mm_send_keystate(struct monitor *monitor)
{
	struct ssh *ssh = active_state;		/* XXX */
	struct sshbuf *m;
	int r;

	if ((m = sshbuf_new()) == NULL)
		fatal("%s: sshbuf_new failed", __func__);
	if ((r = ssh_packet_get_state(ssh, m)) != 0)
		fatal("%s: get_state failed: %s",
		    __func__, ssh_err(r));
	mm_request_send(monitor->m_recvfd, MONITOR_REQ_KEYEXPORT, m);
	debug3("%s: Finished sending state", __func__);
	sshbuf_free(m);
}

int
mm_pty_allocate(int *ptyfd, int *ttyfd, char *namebuf, size_t namebuflen)
{
	Buffer m;
	char *p, *msg;
	int success = 0, tmp1 = -1, tmp2 = -1;

	/* Kludge: ensure there are fds free to receive the pty/tty */
	if ((tmp1 = dup(pmonitor->m_recvfd)) == -1 ||
	    (tmp2 = dup(pmonitor->m_recvfd)) == -1) {
		error("%s: cannot allocate fds for pty", __func__);
		if (tmp1 > 0)
			close(tmp1);
		if (tmp2 > 0)
			close(tmp2);
		return 0;
	}
	close(tmp1);
	close(tmp2);

	buffer_init(&m);
	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTY, &m);

	debug3("%s: waiting for MONITOR_ANS_PTY", __func__);
	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PTY, &m);

	success = buffer_get_int(&m);
	if (success == 0) {
		debug3("%s: pty alloc failed", __func__);
		buffer_free(&m);
		return (0);
	}
	p = buffer_get_string(&m, NULL);
	msg = buffer_get_string(&m, NULL);
	buffer_free(&m);

	strlcpy(namebuf, p, namebuflen); /* Possible truncation */
	free(p);

	buffer_append(&loginmsg, msg, strlen(msg));
	free(msg);

	if ((*ptyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1 ||
	    (*ttyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1)
		fatal("%s: receive fds failed", __func__);

	/* Success */
	return (1);
}

void
mm_session_pty_cleanup2(Session *s)
{
	Buffer m;

	if (s->ttyfd == -1)
		return;
	buffer_init(&m);
	buffer_put_cstring(&m, s->tty);
	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTYCLEANUP, &m);
	buffer_free(&m);

	/* closed dup'ed master */
	if (s->ptymaster != -1 && close(s->ptymaster) < 0)
		error("close(s->ptymaster/%d): %s",
		    s->ptymaster, strerror(errno));

	/* unlink pty from session */
	s->ttyfd = -1;
}

/* Request process termination */

void
mm_terminate(void)
{
	Buffer m;

	buffer_init(&m);
	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_TERM, &m);
	buffer_free(&m);
}

static void
mm_chall_setup(char **name, char **infotxt, u_int *numprompts,
    char ***prompts, u_int **echo_on)
{
	*name = xstrdup("");
	*infotxt = xstrdup("");
	*numprompts = 1;
	*prompts = xcalloc(*numprompts, sizeof(char *));
	*echo_on = xcalloc(*numprompts, sizeof(u_int));
	(*echo_on)[0] = 0;
}

int
mm_bsdauth_query(void *ctx, char **name, char **infotxt,
   u_int *numprompts, char ***prompts, u_int **echo_on)
{
	Buffer m;
	u_int success;
	char *challenge;

	debug3("%s: entering", __func__);

	buffer_init(&m);
	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHQUERY, &m);

	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_BSDAUTHQUERY,
	    &m);
	success = buffer_get_int(&m);
	if (success == 0) {
		debug3("%s: no challenge", __func__);
		buffer_free(&m);
		return (-1);
	}

	/* Get the challenge, and format the response */
	challenge  = buffer_get_string(&m, NULL);
	buffer_free(&m);

	mm_chall_setup(name, infotxt, numprompts, prompts, echo_on);
	(*prompts)[0] = challenge;

	debug3("%s: received challenge: %s", __func__, challenge);

	return (0);
}

int
mm_bsdauth_respond(void *ctx, u_int numresponses, char **responses)
{
	Buffer m;
	int authok;

	debug3("%s: entering", __func__);
	if (numresponses != 1)
		return (-1);

	buffer_init(&m);
	buffer_put_cstring(&m, responses[0]);
	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHRESPOND, &m);

	mm_request_receive_expect(pmonitor->m_recvfd,
	    MONITOR_ANS_BSDAUTHRESPOND, &m);

	authok = buffer_get_int(&m);
	buffer_free(&m);

	return ((authok == 0) ? -1 : 0);
}

#ifdef GSSAPI
OM_uint32
mm_ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID goid)
{
	Buffer m;
	OM_uint32 major;

	/* Client doesn't get to see the context */
	*ctx = NULL;

	buffer_init(&m);
	buffer_put_string(&m, goid->elements, goid->length);

	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSETUP, &m);
	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSETUP, &m);

	major = buffer_get_int(&m);

	buffer_free(&m);
	return (major);
}

OM_uint32
mm_ssh_gssapi_accept_ctx(Gssctxt *ctx, gss_buffer_desc *in,
    gss_buffer_desc *out, OM_uint32 *flags)
{
	Buffer m;
	OM_uint32 major;
	u_int len;

	buffer_init(&m);
	buffer_put_string(&m, in->value, in->length);

	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSTEP, &m);
	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSTEP, &m);

	major = buffer_get_int(&m);
	out->value = buffer_get_string(&m, &len);
	out->length = len;
	if (flags)
		*flags = buffer_get_int(&m);

	buffer_free(&m);

	return (major);
}

OM_uint32
mm_ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic)
{
	Buffer m;
	OM_uint32 major;

	buffer_init(&m);
	buffer_put_string(&m, gssbuf->value, gssbuf->length);
	buffer_put_string(&m, gssmic->value, gssmic->length);

	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSCHECKMIC, &m);
	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSCHECKMIC,
	    &m);

	major = buffer_get_int(&m);
	buffer_free(&m);
	return(major);
}

int
mm_ssh_gssapi_userok(char *user)
{
	Buffer m;
	int authenticated = 0;

	buffer_init(&m);

	mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSUSEROK, &m);
	mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSUSEROK,
				  &m);

	authenticated = buffer_get_int(&m);

	buffer_free(&m);
	debug3("%s: user %sauthenticated",__func__, authenticated ? "" : "not ");
	return (authenticated);
}
#endif /* GSSAPI */



Generated by: GCOVR (Version 3.3)

Line	Branch	Exec	Source
1			/* $OpenBSD: monitor_wrap.c,v 1.94 2017/10/02 19:33:20 djm Exp $ */
2			/*
3			* Copyright 2002 Niels Provos <provos@citi.umich.edu>
4			* Copyright 2002 Markus Friedl <markus@openbsd.org>
5			* All rights reserved.
6			*
7			* Redistribution and use in source and binary forms, with or without
8			* modification, are permitted provided that the following conditions
9			* are met:
10			* 1. Redistributions of source code must retain the above copyright
11			* notice, this list of conditions and the following disclaimer.
12			* 2. Redistributions in binary form must reproduce the above copyright
13			* notice, this list of conditions and the following disclaimer in the
14			* documentation and/or other materials provided with the distribution.
15			*
16			* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17			* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18			* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19			* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20			* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21			* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22			* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23			* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24			* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25			* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26			*/
27
28			#include <sys/types.h>
29			#include <sys/uio.h>
30			#include <sys/queue.h>
31
32			#include <errno.h>
33			#include <pwd.h>
34			#include <signal.h>
35			#include <stdio.h>
36			#include <string.h>
37			#include <unistd.h>
38
39			#ifdef WITH_OPENSSL
40			#include <openssl/bn.h>
41			#include <openssl/dh.h>
42			#endif
43
44			#include "xmalloc.h"
45			#include "ssh.h"
46			#ifdef WITH_OPENSSL
47			#include "dh.h"
48			#endif
49			#include "buffer.h"
50			#include "key.h"
51			#include "cipher.h"
52			#include "kex.h"
53			#include "hostfile.h"
54			#include "auth.h"
55			#include "auth-options.h"
56			#include "packet.h"
57			#include "mac.h"
58			#include "log.h"
59			#include <zlib.h>
60			#include "monitor.h"
61			#ifdef GSSAPI
62			#include "ssh-gss.h"
63			#endif
64			#include "monitor_wrap.h"
65			#include "atomicio.h"
66			#include "monitor_fdpass.h"
67			#include "misc.h"
68			#include "uuencode.h"
69
70			#include "channels.h"
71			#include "session.h"
72			#include "servconf.h"
73
74			#include "ssherr.h"
75
76			/* Imports */
77			extern z_stream incoming_stream;
78			extern z_stream outgoing_stream;
79			extern struct monitor *pmonitor;
80			extern Buffer loginmsg;
81			extern ServerOptions options;
82
83			void
84			mm_log_handler(LogLevel level, const char msg, void ctx)
85			{
86			Buffer log_msg;
87			struct monitor mon = (struct monitor )ctx;
88
89			if (mon->m_log_sendfd == -1)
90			fatal("%s: no log channel", __func__);
91
92			buffer_init(&log_msg);
93			/*
94			* Placeholder for packet length. Will be filled in with the actual
95			* packet length once the packet has been constucted. This saves
96			* fragile math.
97			*/
98			buffer_put_int(&log_msg, 0);
99
100			buffer_put_int(&log_msg, level);
101			buffer_put_cstring(&log_msg, msg);
102			put_u32(buffer_ptr(&log_msg), buffer_len(&log_msg) - 4);
103			if (atomicio(vwrite, mon->m_log_sendfd, buffer_ptr(&log_msg),
104			buffer_len(&log_msg)) != buffer_len(&log_msg))
105			fatal("%s: write: %s", __func__, strerror(errno));
106			buffer_free(&log_msg);
107			}
108
109			int
110			mm_is_monitor(void)
111			{
112			/*
113			* m_pid is only set in the privileged part, and
114			* points to the unprivileged child.
115			*/
116			return (pmonitor && pmonitor->m_pid > 0);
117			}
118
119			void
120			mm_request_send(int sock, enum monitor_reqtype type, Buffer *m)
121			{
122			u_int mlen = buffer_len(m);
123			u_char buf[5];
124
125			debug3("%s entering: type %d", __func__, type);
126
127			put_u32(buf, mlen + 1);
128			buf[4] = (u_char) type; /* 1st byte of payload is mesg-type */
129			if (atomicio(vwrite, sock, buf, sizeof(buf)) != sizeof(buf))
130			fatal("%s: write: %s", __func__, strerror(errno));
131			if (atomicio(vwrite, sock, buffer_ptr(m), mlen) != mlen)
132			fatal("%s: write: %s", __func__, strerror(errno));
133			}
134
135			void
136			mm_request_receive(int sock, Buffer *m)
137			{
138			u_char buf[4];
139			u_int msg_len;
140
141			debug3("%s entering", __func__);
142
143			if (atomicio(read, sock, buf, sizeof(buf)) != sizeof(buf)) {
144			if (errno == EPIPE)
145			cleanup_exit(255);
146			fatal("%s: read: %s", __func__, strerror(errno));
147			}
148			msg_len = get_u32(buf);
149			if (msg_len > 256 * 1024)
150			fatal("%s: read: bad msg_len %d", __func__, msg_len);
151			buffer_clear(m);
152			buffer_append_space(m, msg_len);
153			if (atomicio(read, sock, buffer_ptr(m), msg_len) != msg_len)
154			fatal("%s: read: %s", __func__, strerror(errno));
155			}
156
157			void
158			mm_request_receive_expect(int sock, enum monitor_reqtype type, Buffer *m)
159			{
160			u_char rtype;
161
162			debug3("%s entering: type %d", __func__, type);
163
164			mm_request_receive(sock, m);
165			rtype = buffer_get_char(m);
166			if (rtype != type)
167			fatal("%s: read: rtype %d != type %d", __func__,
168			rtype, type);
169			}
170
171			#ifdef WITH_OPENSSL
172			DH *
173			mm_choose_dh(int min, int nbits, int max)
174			{
175			BIGNUM p, g;
176			int success = 0;
177			Buffer m;
178
179			buffer_init(&m);
180			buffer_put_int(&m, min);
181			buffer_put_int(&m, nbits);
182			buffer_put_int(&m, max);
183
184			mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_MODULI, &m);
185
186			debug3("%s: waiting for MONITOR_ANS_MODULI", __func__);
187			mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_MODULI, &m);
188
189			success = buffer_get_char(&m);
190			if (success == 0)
191			fatal("%s: MONITOR_ANS_MODULI failed", __func__);
192
193			if ((p = BN_new()) == NULL)
194			fatal("%s: BN_new failed", __func__);
195			if ((g = BN_new()) == NULL)
196			fatal("%s: BN_new failed", __func__);
197			buffer_get_bignum2(&m, p);
198			buffer_get_bignum2(&m, g);
199
200			debug3("%s: remaining %d", __func__, buffer_len(&m));
201			buffer_free(&m);
202
203			return (dh_new_group(g, p));
204			}
205			#endif
206
207			int
208			mm_key_sign(struct sshkey key, u_char sigp, u_int lenp,
209			const u_char data, u_int datalen, const char hostkey_alg)
210			{
211			struct kex kex = pmonitor->m_pkex;
212			Buffer m;
213
214			debug3("%s entering", __func__);
215
216			buffer_init(&m);
217			buffer_put_int(&m, kex->host_key_index(key, 0, active_state));
218			buffer_put_string(&m, data, datalen);
219			buffer_put_cstring(&m, hostkey_alg);
220
221			mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_SIGN, &m);
222
223			debug3("%s: waiting for MONITOR_ANS_SIGN", __func__);
224			mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_SIGN, &m);
225			*sigp = buffer_get_string(&m, lenp);
226			buffer_free(&m);
227
228			return (0);
229			}
230
231			struct passwd *
232			mm_getpwnamallow(const char *username)
233			{
234			struct ssh ssh = active_state; / XXX */
235			Buffer m;
236			struct passwd *pw;
237			u_int len, i;
238			ServerOptions *newopts;
239
240			debug3("%s entering", __func__);
241
242			buffer_init(&m);
243			buffer_put_cstring(&m, username);
244
245			mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PWNAM, &m);
246
247			debug3("%s: waiting for MONITOR_ANS_PWNAM", __func__);
248			mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PWNAM, &m);
249
250			if (buffer_get_char(&m) == 0) {
251			pw = NULL;
252			goto out;
253			}
254			pw = buffer_get_string(&m, &len);
255			if (len != sizeof(struct passwd))
256			fatal("%s: struct passwd size mismatch", __func__);
257			pw->pw_name = buffer_get_string(&m, NULL);
258			pw->pw_passwd = buffer_get_string(&m, NULL);
259			pw->pw_gecos = buffer_get_string(&m, NULL);
260			pw->pw_class = buffer_get_string(&m, NULL);
261			pw->pw_dir = buffer_get_string(&m, NULL);
262			pw->pw_shell = buffer_get_string(&m, NULL);
263
264			out:
265			/* copy options block as a Match directive may have changed some */
266			newopts = buffer_get_string(&m, &len);
267			if (len != sizeof(*newopts))
268			fatal("%s: option block size mismatch", __func__);
269
270			#define M_CP_STROPT(x) do { \
271			if (newopts->x != NULL) \
272			newopts->x = buffer_get_string(&m, NULL); \
273			} while (0)
274			#define M_CP_STRARRAYOPT(x, nx) do { \
275			for (i = 0; i < newopts->nx; i++) \
276			newopts->x[i] = buffer_get_string(&m, NULL); \
277			} while (0)
278			#define M_CP_STRARRAYOPT_ALLOC(x, nx) do { \
279			newopts->x = newopts->nx == 0 ? \
280			NULL : xcalloc(newopts->nx, sizeof(*newopts->x)); \
281			M_CP_STRARRAYOPT(x, nx); \
282			} while (0)
283			/* See comment in servconf.h */
284			COPY_MATCH_STRING_OPTS();
285			#undef M_CP_STROPT
286			#undef M_CP_STRARRAYOPT
287			#undef M_CP_STRARRAYOPT_ALLOC
288
289			copy_set_server_options(&options, newopts, 1);
290			log_change_level(options.log_level);
291			process_permitopen(ssh, &options);
292			free(newopts);
293
294			buffer_free(&m);
295
296			return (pw);
297			}
298
299			char *
300			mm_auth2_read_banner(void)
301			{
302			Buffer m;
303			char *banner;
304
305			debug3("%s entering", __func__);
306
307			buffer_init(&m);
308			mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTH2_READ_BANNER, &m);
309			buffer_clear(&m);
310
311			mm_request_receive_expect(pmonitor->m_recvfd,
312			MONITOR_ANS_AUTH2_READ_BANNER, &m);
313			banner = buffer_get_string(&m, NULL);
314			buffer_free(&m);
315
316			/* treat empty banner as missing banner */
317			if (strlen(banner) == 0) {
318			free(banner);
319			banner = NULL;
320			}
321			return (banner);
322			}
323
324			/* Inform the privileged process about service and style */
325
326			void
327			mm_inform_authserv(char service, char style)
328			{
329			Buffer m;
330
331			debug3("%s entering", __func__);
332
333			buffer_init(&m);
334			buffer_put_cstring(&m, service);
335			buffer_put_cstring(&m, style ? style : "");
336
337			mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHSERV, &m);
338
339			buffer_free(&m);
340			}
341
342			/* Do the password authentication */
343			int
344			mm_auth_password(Authctxt authctxt, char password)
345			{
346			Buffer m;
347			int authenticated = 0;
348
349			debug3("%s entering", __func__);
350
351			buffer_init(&m);
352			buffer_put_cstring(&m, password);
353			mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHPASSWORD, &m);
354
355			debug3("%s: waiting for MONITOR_ANS_AUTHPASSWORD", __func__);
356			mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_AUTHPASSWORD, &m);
357
358			authenticated = buffer_get_int(&m);
359
360			buffer_free(&m);
361
362			debug3("%s: user %sauthenticated",
363			__func__, authenticated ? "" : "not ");
364			return (authenticated);
365			}
366
367			int
368			mm_user_key_allowed(struct passwd pw, struct sshkey key,
369			int pubkey_auth_attempt)
370			{
371			return (mm_key_allowed(MM_USERKEY, NULL, NULL, key,
372			pubkey_auth_attempt));
373			}
374
375			int
376			mm_hostbased_key_allowed(struct passwd pw, const char user, const char *host,
377			struct sshkey *key)
378			{
379			return (mm_key_allowed(MM_HOSTKEY, user, host, key, 0));
380			}
381
382			int
383			mm_key_allowed(enum mm_keytype type, const char user, const char host,
384			struct sshkey *key, int pubkey_auth_attempt)
385			{
386			Buffer m;
387			u_char *blob;
388			u_int len;
389			int allowed = 0, have_forced = 0;
390
391			debug3("%s entering", __func__);
392
393			/* Convert the key to a blob and the pass it over */
394			if (!key_to_blob(key, &blob, &len))
395			return (0);
396
397			buffer_init(&m);
398			buffer_put_int(&m, type);
399			buffer_put_cstring(&m, user ? user : "");
400			buffer_put_cstring(&m, host ? host : "");
401			buffer_put_string(&m, blob, len);
402			buffer_put_int(&m, pubkey_auth_attempt);
403			free(blob);
404
405			mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYALLOWED, &m);
406
407			debug3("%s: waiting for MONITOR_ANS_KEYALLOWED", __func__);
408			mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_KEYALLOWED, &m);
409
410			allowed = buffer_get_int(&m);
411
412			/* fake forced command */
413			auth_clear_options();
414			have_forced = buffer_get_int(&m);
415			forced_command = have_forced ? xstrdup("true") : NULL;
416
417			buffer_free(&m);
418
419			return (allowed);
420			}
421
422			/*
423			* This key verify needs to send the key type along, because the
424			* privileged parent makes the decision if the key is allowed
425			* for authentication.
426			*/
427
428			int
429			mm_sshkey_verify(const struct sshkey key, const u_char sig, size_t siglen,
430			const u_char *data, size_t datalen, u_int compat)
431			{
432			Buffer m;
433			u_char *blob;
434			u_int len;
435			u_int encoded_ret = 0;
436
437			debug3("%s entering", __func__);
438
439			/* Convert the key to a blob and the pass it over */
440			if (!key_to_blob(key, &blob, &len))
441			return (0);
442
443			buffer_init(&m);
444			buffer_put_string(&m, blob, len);
445			buffer_put_string(&m, sig, siglen);
446			buffer_put_string(&m, data, datalen);
447			free(blob);
448
449			mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYVERIFY, &m);
450
451			debug3("%s: waiting for MONITOR_ANS_KEYVERIFY", __func__);
452			mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_KEYVERIFY, &m);
453
454			encoded_ret = buffer_get_int(&m);
455
456			buffer_free(&m);
457
458			if (encoded_ret != 0)
459			return SSH_ERR_SIGNATURE_INVALID;
460			return 0;
461			}
462
463			void
464			mm_send_keystate(struct monitor *monitor)
465			{
466			struct ssh ssh = active_state; / XXX */
467			struct sshbuf *m;
468			int r;
469
470			if ((m = sshbuf_new()) == NULL)
471			fatal("%s: sshbuf_new failed", __func__);
472			if ((r = ssh_packet_get_state(ssh, m)) != 0)
473			fatal("%s: get_state failed: %s",
474			__func__, ssh_err(r));
475			mm_request_send(monitor->m_recvfd, MONITOR_REQ_KEYEXPORT, m);
476			debug3("%s: Finished sending state", __func__);
477			sshbuf_free(m);
478			}
479
480			int
481			mm_pty_allocate(int ptyfd, int ttyfd, char *namebuf, size_t namebuflen)
482			{
483			Buffer m;
484			char p, msg;
485			int success = 0, tmp1 = -1, tmp2 = -1;
486
487			/* Kludge: ensure there are fds free to receive the pty/tty */
488			if ((tmp1 = dup(pmonitor->m_recvfd)) == -1 \|\|
489			(tmp2 = dup(pmonitor->m_recvfd)) == -1) {
490			error("%s: cannot allocate fds for pty", __func__);
491			if (tmp1 > 0)
492			close(tmp1);
493			if (tmp2 > 0)
494			close(tmp2);
495			return 0;
496			}
497			close(tmp1);
498			close(tmp2);
499
500			buffer_init(&m);
501			mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTY, &m);
502
503			debug3("%s: waiting for MONITOR_ANS_PTY", __func__);
504			mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PTY, &m);
505
506			success = buffer_get_int(&m);
507			if (success == 0) {
508			debug3("%s: pty alloc failed", __func__);
509			buffer_free(&m);
510			return (0);
511			}
512			p = buffer_get_string(&m, NULL);
513			msg = buffer_get_string(&m, NULL);
514			buffer_free(&m);
515
516			strlcpy(namebuf, p, namebuflen); /* Possible truncation */
517			free(p);
518
519			buffer_append(&loginmsg, msg, strlen(msg));
520			free(msg);
521
522			if ((*ptyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1 \|\|
523			(*ttyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1)
524			fatal("%s: receive fds failed", __func__);
525
526			/* Success */
527			return (1);
528			}
529
530			void
531			mm_session_pty_cleanup2(Session *s)
532			{
533			Buffer m;
534
535			if (s->ttyfd == -1)
536			return;
537			buffer_init(&m);
538			buffer_put_cstring(&m, s->tty);
539			mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTYCLEANUP, &m);
540			buffer_free(&m);
541
542			/* closed dup'ed master */
543			if (s->ptymaster != -1 && close(s->ptymaster) < 0)
544			error("close(s->ptymaster/%d): %s",
545			s->ptymaster, strerror(errno));
546
547			/* unlink pty from session */
548			s->ttyfd = -1;
549			}
550
551			/* Request process termination */
552
553			void
554			mm_terminate(void)
555			{
556			Buffer m;
557
558			buffer_init(&m);
559			mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_TERM, &m);
560			buffer_free(&m);
561			}
562
563			static void
564			mm_chall_setup(char name, char infotxt, u_int *numprompts,
565			char *prompts, u_int echo_on)
566			{
567			*name = xstrdup("");
568			*infotxt = xstrdup("");
569			*numprompts = 1;
570			prompts = xcalloc(numprompts, sizeof(char *));
571			echo_on = xcalloc(numprompts, sizeof(u_int));
572			(*echo_on)[0] = 0;
573			}
574
575			int
576			mm_bsdauth_query(void ctx, char name, char *infotxt,
577			u_int numprompts, char prompts, u_int echo_on)
578			{
579			Buffer m;
580			u_int success;
581			char *challenge;
582
583			debug3("%s: entering", __func__);
584
585			buffer_init(&m);
586			mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHQUERY, &m);
587
588			mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_BSDAUTHQUERY,
589			&m);
590			success = buffer_get_int(&m);
591			if (success == 0) {
592			debug3("%s: no challenge", __func__);
593			buffer_free(&m);
594			return (-1);
595			}
596
597			/* Get the challenge, and format the response */
598			challenge = buffer_get_string(&m, NULL);
599			buffer_free(&m);
600
601			mm_chall_setup(name, infotxt, numprompts, prompts, echo_on);
602			(*prompts)[0] = challenge;
603
604			debug3("%s: received challenge: %s", __func__, challenge);
605
606			return (0);
607			}
608
609			int
610			mm_bsdauth_respond(void ctx, u_int numresponses, char *responses)
611			{
612			Buffer m;
613			int authok;
614
615			debug3("%s: entering", __func__);
616			if (numresponses != 1)
617			return (-1);
618
619			buffer_init(&m);
620			buffer_put_cstring(&m, responses[0]);
621			mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHRESPOND, &m);
622
623			mm_request_receive_expect(pmonitor->m_recvfd,
624			MONITOR_ANS_BSDAUTHRESPOND, &m);
625
626			authok = buffer_get_int(&m);
627			buffer_free(&m);
628
629			return ((authok == 0) ? -1 : 0);
630			}
631
632			#ifdef GSSAPI
633			OM_uint32
634			mm_ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID goid)
635			{
636			Buffer m;
637			OM_uint32 major;
638
639			/* Client doesn't get to see the context */
640			*ctx = NULL;
641
642			buffer_init(&m);
643			buffer_put_string(&m, goid->elements, goid->length);
644
645			mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSETUP, &m);
646			mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSETUP, &m);
647
648			major = buffer_get_int(&m);
649
650			buffer_free(&m);
651			return (major);
652			}
653
654			OM_uint32
655			mm_ssh_gssapi_accept_ctx(Gssctxt ctx, gss_buffer_desc in,
656			gss_buffer_desc out, OM_uint32 flags)
657			{
658			Buffer m;
659			OM_uint32 major;
660			u_int len;
661
662			buffer_init(&m);
663			buffer_put_string(&m, in->value, in->length);
664
665			mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSTEP, &m);
666			mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSTEP, &m);
667
668			major = buffer_get_int(&m);
669			out->value = buffer_get_string(&m, &len);
670			out->length = len;
671			if (flags)
672			*flags = buffer_get_int(&m);
673
674			buffer_free(&m);
675
676			return (major);
677			}
678
679			OM_uint32
680			mm_ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic)
681			{
682			Buffer m;
683			OM_uint32 major;
684
685			buffer_init(&m);
686			buffer_put_string(&m, gssbuf->value, gssbuf->length);
687			buffer_put_string(&m, gssmic->value, gssmic->length);
688
689			mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSCHECKMIC, &m);
690			mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSCHECKMIC,
691			&m);
692
693			major = buffer_get_int(&m);
694			buffer_free(&m);
695			return(major);
696			}
697
698			int
699			mm_ssh_gssapi_userok(char *user)
700			{
701			Buffer m;
702			int authenticated = 0;
703
704			buffer_init(&m);
705
706			mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSUSEROK, &m);
707			mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSUSEROK,
708			&m);
709
710			authenticated = buffer_get_int(&m);
711
712			buffer_free(&m);
713			debug3("%s: user %sauthenticated",__func__, authenticated ? "" : "not ");
714			return (authenticated);
715			}
716			#endif /* GSSAPI */
717