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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:	2017-11-13	Branches:	0	124	0.0 %


/* $OpenBSD: monitor_wrap.c,v 1.95 2017/10/05 15:52:03 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 { \
		newopts->x = newopts->nx == 0 ? \
		    NULL : xcalloc(newopts->nx, sizeof(*newopts->x)); \
		for (i = 0; i < newopts->nx; i++) \
			newopts->x[i] = buffer_get_string(&m, NULL); \
	} while (0)
	/* See comment in servconf.h */
	COPY_MATCH_STRING_OPTS();
#undef M_CP_STROPT
#undef M_CP_STRARRAYOPT

	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 1.95 2017/10/05 15:52:03 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			newopts->x = newopts->nx == 0 ? \
276			NULL : xcalloc(newopts->nx, sizeof(*newopts->x)); \
277			for (i = 0; i < newopts->nx; i++) \
278			newopts->x[i] = buffer_get_string(&m, NULL); \
279			} while (0)
280			/* See comment in servconf.h */
281			COPY_MATCH_STRING_OPTS();
282			#undef M_CP_STROPT
283			#undef M_CP_STRARRAYOPT
284
285			copy_set_server_options(&options, newopts, 1);
286			log_change_level(options.log_level);
287			process_permitopen(ssh, &options);
288			free(newopts);
289
290			buffer_free(&m);
291
292			return (pw);
293			}
294
295			char *
296			mm_auth2_read_banner(void)
297			{
298			Buffer m;
299			char *banner;
300
301			debug3("%s entering", __func__);
302
303			buffer_init(&m);
304			mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTH2_READ_BANNER, &m);
305			buffer_clear(&m);
306
307			mm_request_receive_expect(pmonitor->m_recvfd,
308			MONITOR_ANS_AUTH2_READ_BANNER, &m);
309			banner = buffer_get_string(&m, NULL);
310			buffer_free(&m);
311
312			/* treat empty banner as missing banner */
313			if (strlen(banner) == 0) {
314			free(banner);
315			banner = NULL;
316			}
317			return (banner);
318			}
319
320			/* Inform the privileged process about service and style */
321
322			void
323			mm_inform_authserv(char service, char style)
324			{
325			Buffer m;
326
327			debug3("%s entering", __func__);
328
329			buffer_init(&m);
330			buffer_put_cstring(&m, service);
331			buffer_put_cstring(&m, style ? style : "");
332
333			mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHSERV, &m);
334
335			buffer_free(&m);
336			}
337
338			/* Do the password authentication */
339			int
340			mm_auth_password(Authctxt authctxt, char password)
341			{
342			Buffer m;
343			int authenticated = 0;
344
345			debug3("%s entering", __func__);
346
347			buffer_init(&m);
348			buffer_put_cstring(&m, password);
349			mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUTHPASSWORD, &m);
350
351			debug3("%s: waiting for MONITOR_ANS_AUTHPASSWORD", __func__);
352			mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_AUTHPASSWORD, &m);
353
354			authenticated = buffer_get_int(&m);
355
356			buffer_free(&m);
357
358			debug3("%s: user %sauthenticated",
359			__func__, authenticated ? "" : "not ");
360			return (authenticated);
361			}
362
363			int
364			mm_user_key_allowed(struct passwd pw, struct sshkey key,
365			int pubkey_auth_attempt)
366			{
367			return (mm_key_allowed(MM_USERKEY, NULL, NULL, key,
368			pubkey_auth_attempt));
369			}
370
371			int
372			mm_hostbased_key_allowed(struct passwd pw, const char user, const char *host,
373			struct sshkey *key)
374			{
375			return (mm_key_allowed(MM_HOSTKEY, user, host, key, 0));
376			}
377
378			int
379			mm_key_allowed(enum mm_keytype type, const char user, const char host,
380			struct sshkey *key, int pubkey_auth_attempt)
381			{
382			Buffer m;
383			u_char *blob;
384			u_int len;
385			int allowed = 0, have_forced = 0;
386
387			debug3("%s entering", __func__);
388
389			/* Convert the key to a blob and the pass it over */
390			if (!key_to_blob(key, &blob, &len))
391			return (0);
392
393			buffer_init(&m);
394			buffer_put_int(&m, type);
395			buffer_put_cstring(&m, user ? user : "");
396			buffer_put_cstring(&m, host ? host : "");
397			buffer_put_string(&m, blob, len);
398			buffer_put_int(&m, pubkey_auth_attempt);
399			free(blob);
400
401			mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYALLOWED, &m);
402
403			debug3("%s: waiting for MONITOR_ANS_KEYALLOWED", __func__);
404			mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_KEYALLOWED, &m);
405
406			allowed = buffer_get_int(&m);
407
408			/* fake forced command */
409			auth_clear_options();
410			have_forced = buffer_get_int(&m);
411			forced_command = have_forced ? xstrdup("true") : NULL;
412
413			buffer_free(&m);
414
415			return (allowed);
416			}
417
418			/*
419			* This key verify needs to send the key type along, because the
420			* privileged parent makes the decision if the key is allowed
421			* for authentication.
422			*/
423
424			int
425			mm_sshkey_verify(const struct sshkey key, const u_char sig, size_t siglen,
426			const u_char *data, size_t datalen, u_int compat)
427			{
428			Buffer m;
429			u_char *blob;
430			u_int len;
431			u_int encoded_ret = 0;
432
433			debug3("%s entering", __func__);
434
435			/* Convert the key to a blob and the pass it over */
436			if (!key_to_blob(key, &blob, &len))
437			return (0);
438
439			buffer_init(&m);
440			buffer_put_string(&m, blob, len);
441			buffer_put_string(&m, sig, siglen);
442			buffer_put_string(&m, data, datalen);
443			free(blob);
444
445			mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYVERIFY, &m);
446
447			debug3("%s: waiting for MONITOR_ANS_KEYVERIFY", __func__);
448			mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_KEYVERIFY, &m);
449
450			encoded_ret = buffer_get_int(&m);
451
452			buffer_free(&m);
453
454			if (encoded_ret != 0)
455			return SSH_ERR_SIGNATURE_INVALID;
456			return 0;
457			}
458
459			void
460			mm_send_keystate(struct monitor *monitor)
461			{
462			struct ssh ssh = active_state; / XXX */
463			struct sshbuf *m;
464			int r;
465
466			if ((m = sshbuf_new()) == NULL)
467			fatal("%s: sshbuf_new failed", __func__);
468			if ((r = ssh_packet_get_state(ssh, m)) != 0)
469			fatal("%s: get_state failed: %s",
470			__func__, ssh_err(r));
471			mm_request_send(monitor->m_recvfd, MONITOR_REQ_KEYEXPORT, m);
472			debug3("%s: Finished sending state", __func__);
473			sshbuf_free(m);
474			}
475
476			int
477			mm_pty_allocate(int ptyfd, int ttyfd, char *namebuf, size_t namebuflen)
478			{
479			Buffer m;
480			char p, msg;
481			int success = 0, tmp1 = -1, tmp2 = -1;
482
483			/* Kludge: ensure there are fds free to receive the pty/tty */
484			if ((tmp1 = dup(pmonitor->m_recvfd)) == -1 \|\|
485			(tmp2 = dup(pmonitor->m_recvfd)) == -1) {
486			error("%s: cannot allocate fds for pty", __func__);
487			if (tmp1 > 0)
488			close(tmp1);
489			if (tmp2 > 0)
490			close(tmp2);
491			return 0;
492			}
493			close(tmp1);
494			close(tmp2);
495
496			buffer_init(&m);
497			mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTY, &m);
498
499			debug3("%s: waiting for MONITOR_ANS_PTY", __func__);
500			mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_PTY, &m);
501
502			success = buffer_get_int(&m);
503			if (success == 0) {
504			debug3("%s: pty alloc failed", __func__);
505			buffer_free(&m);
506			return (0);
507			}
508			p = buffer_get_string(&m, NULL);
509			msg = buffer_get_string(&m, NULL);
510			buffer_free(&m);
511
512			strlcpy(namebuf, p, namebuflen); /* Possible truncation */
513			free(p);
514
515			buffer_append(&loginmsg, msg, strlen(msg));
516			free(msg);
517
518			if ((*ptyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1 \|\|
519			(*ttyfd = mm_receive_fd(pmonitor->m_recvfd)) == -1)
520			fatal("%s: receive fds failed", __func__);
521
522			/* Success */
523			return (1);
524			}
525
526			void
527			mm_session_pty_cleanup2(Session *s)
528			{
529			Buffer m;
530
531			if (s->ttyfd == -1)
532			return;
533			buffer_init(&m);
534			buffer_put_cstring(&m, s->tty);
535			mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_PTYCLEANUP, &m);
536			buffer_free(&m);
537
538			/* closed dup'ed master */
539			if (s->ptymaster != -1 && close(s->ptymaster) < 0)
540			error("close(s->ptymaster/%d): %s",
541			s->ptymaster, strerror(errno));
542
543			/* unlink pty from session */
544			s->ttyfd = -1;
545			}
546
547			/* Request process termination */
548
549			void
550			mm_terminate(void)
551			{
552			Buffer m;
553
554			buffer_init(&m);
555			mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_TERM, &m);
556			buffer_free(&m);
557			}
558
559			static void
560			mm_chall_setup(char name, char infotxt, u_int *numprompts,
561			char *prompts, u_int echo_on)
562			{
563			*name = xstrdup("");
564			*infotxt = xstrdup("");
565			*numprompts = 1;
566			prompts = xcalloc(numprompts, sizeof(char *));
567			echo_on = xcalloc(numprompts, sizeof(u_int));
568			(*echo_on)[0] = 0;
569			}
570
571			int
572			mm_bsdauth_query(void ctx, char name, char *infotxt,
573			u_int numprompts, char prompts, u_int echo_on)
574			{
575			Buffer m;
576			u_int success;
577			char *challenge;
578
579			debug3("%s: entering", __func__);
580
581			buffer_init(&m);
582			mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHQUERY, &m);
583
584			mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_BSDAUTHQUERY,
585			&m);
586			success = buffer_get_int(&m);
587			if (success == 0) {
588			debug3("%s: no challenge", __func__);
589			buffer_free(&m);
590			return (-1);
591			}
592
593			/* Get the challenge, and format the response */
594			challenge = buffer_get_string(&m, NULL);
595			buffer_free(&m);
596
597			mm_chall_setup(name, infotxt, numprompts, prompts, echo_on);
598			(*prompts)[0] = challenge;
599
600			debug3("%s: received challenge: %s", __func__, challenge);
601
602			return (0);
603			}
604
605			int
606			mm_bsdauth_respond(void ctx, u_int numresponses, char *responses)
607			{
608			Buffer m;
609			int authok;
610
611			debug3("%s: entering", __func__);
612			if (numresponses != 1)
613			return (-1);
614
615			buffer_init(&m);
616			buffer_put_cstring(&m, responses[0]);
617			mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_BSDAUTHRESPOND, &m);
618
619			mm_request_receive_expect(pmonitor->m_recvfd,
620			MONITOR_ANS_BSDAUTHRESPOND, &m);
621
622			authok = buffer_get_int(&m);
623			buffer_free(&m);
624
625			return ((authok == 0) ? -1 : 0);
626			}
627
628			#ifdef GSSAPI
629			OM_uint32
630			mm_ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID goid)
631			{
632			Buffer m;
633			OM_uint32 major;
634
635			/* Client doesn't get to see the context */
636			*ctx = NULL;
637
638			buffer_init(&m);
639			buffer_put_string(&m, goid->elements, goid->length);
640
641			mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSETUP, &m);
642			mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSETUP, &m);
643
644			major = buffer_get_int(&m);
645
646			buffer_free(&m);
647			return (major);
648			}
649
650			OM_uint32
651			mm_ssh_gssapi_accept_ctx(Gssctxt ctx, gss_buffer_desc in,
652			gss_buffer_desc out, OM_uint32 flags)
653			{
654			Buffer m;
655			OM_uint32 major;
656			u_int len;
657
658			buffer_init(&m);
659			buffer_put_string(&m, in->value, in->length);
660
661			mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSTEP, &m);
662			mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSTEP, &m);
663
664			major = buffer_get_int(&m);
665			out->value = buffer_get_string(&m, &len);
666			out->length = len;
667			if (flags)
668			*flags = buffer_get_int(&m);
669
670			buffer_free(&m);
671
672			return (major);
673			}
674
675			OM_uint32
676			mm_ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic)
677			{
678			Buffer m;
679			OM_uint32 major;
680
681			buffer_init(&m);
682			buffer_put_string(&m, gssbuf->value, gssbuf->length);
683			buffer_put_string(&m, gssmic->value, gssmic->length);
684
685			mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSCHECKMIC, &m);
686			mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSCHECKMIC,
687			&m);
688
689			major = buffer_get_int(&m);
690			buffer_free(&m);
691			return(major);
692			}
693
694			int
695			mm_ssh_gssapi_userok(char *user)
696			{
697			Buffer m;
698			int authenticated = 0;
699
700			buffer_init(&m);
701
702			mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSUSEROK, &m);
703			mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSUSEROK,
704			&m);
705
706			authenticated = buffer_get_int(&m);
707
708			buffer_free(&m);
709			debug3("%s: user %sauthenticated",__func__, authenticated ? "" : "not ");
710			return (authenticated);
711			}
712			#endif /* GSSAPI */
713