[openssh.git] / auth1.c

/*
 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
 *                    All rights reserved
 *
 * As far as I am concerned, the code I have written for this software
 * can be used freely for any purpose.  Any derived versions of this
 * software must be clearly marked as such, and if the derived work is
 * incompatible with the protocol description in the RFC file, it must be
 * called by a name other than "ssh" or "Secure Shell".
 */

#include "includes.h"
RCSID("$OpenBSD: auth1.c,v 1.11 2001/01/18 16:59:59 markus Exp $");

#ifdef HAVE_OSF_SIA
# include <sia.h>
# include <siad.h>
#endif

#include "xmalloc.h"
#include "rsa.h"
#include "ssh.h"
#include "packet.h"
#include "buffer.h"
#include "mpaux.h"
#include "servconf.h"
#include "compat.h"
#include "auth.h"
#include "session.h"

/* import */
extern ServerOptions options;
extern char *forced_command;

#ifdef WITH_AIXAUTHENTICATE
extern char *aixloginmsg;
#endif /* WITH_AIXAUTHENTICATE */
#ifdef HAVE_OSF_SIA
extern int saved_argc;
extern char **saved_argv;
#endif /* HAVE_OSF_SIA */

/*
 * convert ssh auth msg type into description
 */
char *
get_authname(int type)
{
	static char buf[1024];
	switch (type) {
	case SSH_CMSG_AUTH_PASSWORD:
		return "password";
	case SSH_CMSG_AUTH_RSA:
		return "rsa";
	case SSH_CMSG_AUTH_RHOSTS_RSA:
		return "rhosts-rsa";
	case SSH_CMSG_AUTH_RHOSTS:
		return "rhosts";
	case SSH_CMSG_AUTH_TIS:
	case SSH_CMSG_AUTH_TIS_RESPONSE:
		return "challenge-response";
#ifdef KRB4
	case SSH_CMSG_AUTH_KERBEROS:
		return "kerberos";
#endif
	}
	snprintf(buf, sizeof buf, "bad-auth-msg-%d", type);
	return buf;
}

/*
 * read packets, try to authenticate the user and
 * return only if authentication is successful
 */
void
do_authloop(Authctxt *authctxt)
{
	int authenticated = 0;
	u_int bits;
	RSA *client_host_key;
	BIGNUM *n;
	char *client_user, *password;
	char info[1024];
	u_int dlen;
	int plen, nlen, elen;
	u_int ulen;
	int type = 0;
	struct passwd *pw = authctxt->pw;

	debug("Attempting authentication for %s%.100s.",
	     authctxt->valid ? "" : "illegal user ", authctxt->user);

	/* If the user has no password, accept authentication immediately. */
	if (options.password_authentication &&
#ifdef KRB4
	    (!options.kerberos_authentication || options.kerberos_or_local_passwd) &&
#endif
#ifdef USE_PAM
	    auth_pam_password(pw, password)) {
#else
	    auth_password(pw, "")) {
#endif
		auth_log(authctxt, 1, "without authentication", "");
		return;
	}

	/* Indicate that authentication is needed. */
	packet_start(SSH_SMSG_FAILURE);
	packet_send();
	packet_write_wait();

	client_user = NULL;

	for (;;) {
		/* default to fail */
		authenticated = 0;

		info[0] = '\0';

		/* Get a packet from the client. */
		type = packet_read(&plen);

		/* Process the packet. */
		switch (type) {
#ifdef AFS
		case SSH_CMSG_HAVE_KERBEROS_TGT:
			if (!options.kerberos_tgt_passing) {
				verbose("Kerberos tgt passing disabled.");
				break;
			} else {
				/* Accept Kerberos tgt. */
				char *tgt = packet_get_string(&dlen);
				packet_integrity_check(plen, 4 + dlen, type);
				if (!auth_kerberos_tgt(pw, tgt))
					verbose("Kerberos tgt REFUSED for %.100s", authctxt->user);
				xfree(tgt);
			}
			continue;

		case SSH_CMSG_HAVE_AFS_TOKEN:
			if (!options.afs_token_passing || !k_hasafs()) {
				verbose("AFS token passing disabled.");
				break;
			} else {
				/* Accept AFS token. */
				char *token_string = packet_get_string(&dlen);
				packet_integrity_check(plen, 4 + dlen, type);
				if (!auth_afs_token(pw, token_string))
					verbose("AFS token REFUSED for %.100s", authctxt->user);
				xfree(token_string);
			}
			continue;
#endif /* AFS */
#ifdef KRB4
		case SSH_CMSG_AUTH_KERBEROS:
			if (!options.kerberos_authentication) {
				verbose("Kerberos authentication disabled.");
				break;
			} else {
				/* Try Kerberos v4 authentication. */
				KTEXT_ST auth;
				char *tkt_user = NULL;
				char *kdata = packet_get_string((u_int *) &auth.length);
				packet_integrity_check(plen, 4 + auth.length, type);

				if (authctxt->valid) {
					if (auth.length < MAX_KTXT_LEN)
						memcpy(auth.dat, kdata, auth.length);
					authenticated = auth_krb4(pw->pw_name, &auth, &tkt_user);
					if (authenticated) {
						snprintf(info, sizeof info,
						    " tktuser %.100s", tkt_user);
						xfree(tkt_user);
					}
				}
				xfree(kdata);
			}
			break;
#endif /* KRB4 */

		case SSH_CMSG_AUTH_RHOSTS:
			if (!options.rhosts_authentication) {
				verbose("Rhosts authentication disabled.");
				break;
			}
			/*
			 * Get client user name.  Note that we just have to
			 * trust the client; this is one reason why rhosts
			 * authentication is insecure. (Another is
			 * IP-spoofing on a local network.)
			 */
			client_user = packet_get_string(&ulen);
			packet_integrity_check(plen, 4 + ulen, type);

			/* Try to authenticate using /etc/hosts.equiv and .rhosts. */
			authenticated = auth_rhosts(pw, client_user);

			snprintf(info, sizeof info, " ruser %.100s", client_user);
			break;

		case SSH_CMSG_AUTH_RHOSTS_RSA:
			if (!options.rhosts_rsa_authentication) {
				verbose("Rhosts with RSA authentication disabled.");
				break;
			}
			/*
			 * Get client user name.  Note that we just have to
			 * trust the client; root on the client machine can
			 * claim to be any user.
			 */
			client_user = packet_get_string(&ulen);

			/* Get the client host key. */
			client_host_key = RSA_new();
			if (client_host_key == NULL)
				fatal("RSA_new failed");
			client_host_key->e = BN_new();
			client_host_key->n = BN_new();
			if (client_host_key->e == NULL || client_host_key->n == NULL)
				fatal("BN_new failed");
			bits = packet_get_int();
			packet_get_bignum(client_host_key->e, &elen);
			packet_get_bignum(client_host_key->n, &nlen);

			if (bits != BN_num_bits(client_host_key->n))
				verbose("Warning: keysize mismatch for client_host_key: "
				    "actual %d, announced %d", BN_num_bits(client_host_key->n), bits);
			packet_integrity_check(plen, (4 + ulen) + 4 + elen + nlen, type);

			authenticated = auth_rhosts_rsa(pw, client_user, client_host_key);
			RSA_free(client_host_key);

			snprintf(info, sizeof info, " ruser %.100s", client_user);
			break;

		case SSH_CMSG_AUTH_RSA:
			if (!options.rsa_authentication) {
				verbose("RSA authentication disabled.");
				break;
			}
			/* RSA authentication requested. */
			n = BN_new();
			packet_get_bignum(n, &nlen);
			packet_integrity_check(plen, nlen, type);
			authenticated = auth_rsa(pw, n);
			BN_clear_free(n);
			break;

		case SSH_CMSG_AUTH_PASSWORD:
			if (!options.password_authentication) {
				verbose("Password authentication disabled.");
				break;
			}
			/*
			 * Read user password.  It is in plain text, but was
			 * transmitted over the encrypted channel so it is
			 * not visible to an outside observer.
			 */
			password = packet_get_string(&dlen);
			packet_integrity_check(plen, 4 + dlen, type);

#ifdef USE_PAM
			/* Do PAM auth with password */
			authenticated = auth_pam_password(pw, password);
#elif defined(HAVE_OSF_SIA)
			/* Do SIA auth with password */
			if (sia_validate_user(NULL, saved_argc, saved_argv, 
				get_canonical_hostname(), pw->pw_name, NULL, 0, 
				NULL, password) == SIASUCCESS) {
				authenticated = 1;
			}
#else /* !USE_PAM && !HAVE_OSF_SIA */
 			/* Try authentication with the password. */
			authenticated = auth_password(pw, password);
#endif /* USE_PAM */

			memset(password, 0, strlen(password));
			xfree(password);
			break;

#ifdef SKEY			/* ISSUE: Is this right?  we don't define
					having skey_authentication in
					servconf.h by default so I assume
					we need to deal with this via #ifdef
					in some reasonable way */
		case SSH_CMSG_AUTH_TIS:
			debug("rcvd SSH_CMSG_AUTH_TIS");
			if (options.skey_authentication == 1) {
				char *challenge = get_challenge(authctxt, authctxt->style);
				if (challenge != NULL) {
					debug("sending challenge '%s'", challenge);
					packet_start(SSH_SMSG_AUTH_TIS_CHALLENGE);
					packet_put_cstring(challenge);
					packet_send();
					packet_write_wait();
					continue;
				}
			}
			break;
		case SSH_CMSG_AUTH_TIS_RESPONSE:
			debug("rcvd SSH_CMSG_AUTH_TIS_RESPONSE");
			if (options.skey_authentication == 1) {
				char *response = packet_get_string(&dlen);
				debug("got response '%s'", response);
				packet_integrity_check(plen, 4 + dlen, type);
				authenticated = verify_response(authctxt, response);
				memset(response, 'r', dlen);
				xfree(response);
			}
			break;
#endif					/* ISSUE: End of wrong SKEY defines */

		default:
			/*
			 * Any unknown messages will be ignored (and failure
			 * returned) during authentication.
			 */
			log("Unknown message during authentication: type %d", type);
			break;
		}
		if (!authctxt->valid && authenticated)
			fatal("INTERNAL ERROR: authenticated invalid user %s",
			    authctxt->user);

#ifdef HAVE_CYGWIN		/* ISSUE: Right place? */
		if (authenticated && 
		    !check_nt_auth(type == SSH_CMSG_AUTH_PASSWORD,pw->pw_uid)) {
			packet_disconnect("Authentication rejected for uid %d.",
			(int)pw->pw_uid);
			authenticated = 0;
		}
#endif

		/* Special handling for root */
		if (authenticated && authctxt->pw->pw_uid == 0 && !auth_root_allowed())
			authenticated = 0;

#ifdef USE_PAM			/* ISSUE: Right place? */
		if (authenticated && !do_pam_account(pw->pw_name, client_user))
			authenticated = 0;
#endif

		/* Log before sending the reply */
		auth_log(authctxt, authenticated, get_authname(type), info);

		if (client_user != NULL) {
			xfree(client_user);
			client_user = NULL;
		}

		if (authenticated)
			return;

	if (authctxt->failures++ > AUTH_FAIL_MAX) {
#ifdef WITH_AIXAUTHENTICATE 
			loginfailed(user,get_canonical_hostname(),"ssh");
#endif /* WITH_AIXAUTHENTICATE */
			packet_disconnect(AUTH_FAIL_MSG, authctxt->user);
		}

		packet_start(SSH_SMSG_FAILURE);
		packet_send();
		packet_write_wait();
	}
}

/*
 * Performs authentication of an incoming connection.  Session key has already
 * been exchanged and encryption is enabled.
 */
void
do_authentication()
{
	Authctxt *authctxt;
	struct passwd *pw;
	int plen;
	u_int ulen;
	char *user, *style = NULL;

	/* Get the name of the user that we wish to log in as. */
	packet_read_expect(&plen, SSH_CMSG_USER);

	/* Get the user name. */
	user = packet_get_string(&ulen);
	packet_integrity_check(plen, (4 + ulen), SSH_CMSG_USER);

	if ((style = strchr(user, ':')) != NULL)
		*style++ = 0;

	authctxt = authctxt_new();
	authctxt->user = user;
	authctxt->style = style;

	setproctitle("%s", user);

#ifdef AFS
	/* If machine has AFS, set process authentication group. */
	if (k_hasafs()) {
		k_setpag();
		k_unlog();
	}
#endif /* AFS */

	/* Verify that the user is a valid user. */
	pw = getpwnam(user);
	if (pw && allowed_user(pw)) {
		authctxt->valid = 1;
		pw = pwcopy(pw);
	} else {
		debug("do_authentication: illegal user %s", user);
		pw = NULL;
	}
	authctxt->pw = pw;

#ifdef USE_PAM
	if (pw)
		start_pam(user);
#endif

	/*
	 * If we are not running as root, the user must have the same uid as
	 * the server. (Unless you are running Windows)
	 */
#ifndef HAVE_CYGWIN
	if (getuid() != 0 && pw && pw->pw_uid != getuid())
		packet_disconnect("Cannot change user when server not running as root.");
#endif

	/*
         * Loop until the user has been authenticated or the connection is
         * closed, do_authloop() returns only if authentication is successful
         */
	do_authloop(authctxt);

	/* The user has been authenticated and accepted. */
	packet_start(SSH_SMSG_SUCCESS);
	packet_send();
	packet_write_wait();

#ifdef WITH_AIXAUTHENTICATE
	/* We don't have a pty yet, so just label the line as "ssh" */
	if (loginsuccess(authctxt->user,get_canonical_hostname(),"ssh",&aixloginmsg) < 0)
		aixloginmsg = NULL;
#endif /* WITH_AIXAUTHENTICATE */

	xfree(authctxt->user);
	xfree(authctxt);

	/* Perform session preparation. */
	do_authenticated(pw);
}
Commit	Line	Data
a306f2dd	1	/*
	2	* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
	3	* All rights reserved
bcbf86ec	4	*
	5	* As far as I am concerned, the code I have written for this software
	6	* can be used freely for any purpose. Any derived versions of this
	7	* software must be clearly marked as such, and if the derived work is
	8	* incompatible with the protocol description in the RFC file, it must be
	9	* called by a name other than "ssh" or "Secure Shell".
a306f2dd	10	*/
	11
	12	#include "includes.h"
59c97189	13	RCSID("$OpenBSD: auth1.c,v 1.11 2001/01/18 16:59:59 markus Exp $");
94ec8c6b	14
	15	#ifdef HAVE_OSF_SIA
	16	# include <sia.h>
	17	# include <siad.h>
	18	#endif
a306f2dd	19
	20	#include "xmalloc.h"
	21	#include "rsa.h"
	22	#include "ssh.h"
	23	#include "packet.h"
	24	#include "buffer.h"
a306f2dd	25	#include "mpaux.h"
	26	#include "servconf.h"
	27	#include "compat.h"
	28	#include "auth.h"
	29	#include "session.h"
	30
	31	/* import */
	32	extern ServerOptions options;
	33	extern char *forced_command;
94ec8c6b	34
	35	#ifdef WITH_AIXAUTHENTICATE
	36	extern char *aixloginmsg;
	37	#endif /* WITH_AIXAUTHENTICATE */
b3f162ba	38	#ifdef HAVE_OSF_SIA
	39	extern int saved_argc;
	40	extern char **saved_argv;
	41	#endif /* HAVE_OSF_SIA */
a306f2dd	42
	43	/*
	44	* convert ssh auth msg type into description
	45	*/
	46	char *
	47	get_authname(int type)
	48	{
	49	static char buf[1024];
	50	switch (type) {
	51	case SSH_CMSG_AUTH_PASSWORD:
	52	return "password";
	53	case SSH_CMSG_AUTH_RSA:
	54	return "rsa";
	55	case SSH_CMSG_AUTH_RHOSTS_RSA:
	56	return "rhosts-rsa";
	57	case SSH_CMSG_AUTH_RHOSTS:
	58	return "rhosts";
59c97189	59	case SSH_CMSG_AUTH_TIS:
	60	case SSH_CMSG_AUTH_TIS_RESPONSE:
	61	return "challenge-response";
a306f2dd	62	#ifdef KRB4
	63	case SSH_CMSG_AUTH_KERBEROS:
	64	return "kerberos";
a306f2dd	65	#endif
	66	}
	67	snprintf(buf, sizeof buf, "bad-auth-msg-%d", type);
	68	return buf;
	69	}
	70
	71	/*
59c97189	72	* read packets, try to authenticate the user and
59c97189	73	* return only if authentication is successful
a306f2dd	74	*/
a306f2dd	75	void
59c97189	76	do_authloop(Authctxt *authctxt)
a306f2dd	77	{
94ec8c6b	78	int authenticated = 0;
1e3b8b07	79	u_int bits;
a306f2dd	80	RSA *client_host_key;
a306f2dd	81	BIGNUM *n;
94ec8c6b	82	char client_user, password;
59c97189	83	char info[1024];
1e3b8b07	84	u_int dlen;
a306f2dd	85	int plen, nlen, elen;
1e3b8b07	86	u_int ulen;
a306f2dd	87	int type = 0;
59c97189	88	struct passwd *pw = authctxt->pw;
	89
	90	debug("Attempting authentication for %s%.100s.",
	91	authctxt->valid ? "" : "illegal user ", authctxt->user);
	92
	93	/* If the user has no password, accept authentication immediately. */
	94	if (options.password_authentication &&
	95	#ifdef KRB4
	96	(!options.kerberos_authentication \|\| options.kerberos_or_local_passwd) &&
	97	#endif
f4ebf0e8	98	#ifdef USE_PAM
59c97189	99	auth_pam_password(pw, password)) {
	100	#else
	101	auth_password(pw, "")) {
	102	#endif
	103	auth_log(authctxt, 1, "without authentication", "");
	104	return;
	105	}
a306f2dd	106
	107	/* Indicate that authentication is needed. */
	108	packet_start(SSH_SMSG_FAILURE);
	109	packet_send();
	110	packet_write_wait();
	111
94ec8c6b	112	client_user = NULL;
94ec8c6b	113
59c97189	114	for (;;) {
94ec8c6b	115	/* default to fail */
	116	authenticated = 0;
	117
59c97189	118	info[0] = '\0';
a306f2dd	119
	120	/* Get a packet from the client. */
	121	type = packet_read(&plen);
	122
	123	/* Process the packet. */
	124	switch (type) {
	125	#ifdef AFS
	126	case SSH_CMSG_HAVE_KERBEROS_TGT:
	127	if (!options.kerberos_tgt_passing) {
a306f2dd	128	verbose("Kerberos tgt passing disabled.");
	129	break;
	130	} else {
	131	/* Accept Kerberos tgt. */
	132	char *tgt = packet_get_string(&dlen);
	133	packet_integrity_check(plen, 4 + dlen, type);
	134	if (!auth_kerberos_tgt(pw, tgt))
59c97189	135	verbose("Kerberos tgt REFUSED for %.100s", authctxt->user);
a306f2dd	136	xfree(tgt);
	137	}
	138	continue;
	139
	140	case SSH_CMSG_HAVE_AFS_TOKEN:
	141	if (!options.afs_token_passing \|\| !k_hasafs()) {
a306f2dd	142	verbose("AFS token passing disabled.");
	143	break;
	144	} else {
	145	/* Accept AFS token. */
	146	char *token_string = packet_get_string(&dlen);
	147	packet_integrity_check(plen, 4 + dlen, type);
	148	if (!auth_afs_token(pw, token_string))
59c97189	149	verbose("AFS token REFUSED for %.100s", authctxt->user);
a306f2dd	150	xfree(token_string);
	151	}
	152	continue;
	153	#endif /* AFS */
	154	#ifdef KRB4
	155	case SSH_CMSG_AUTH_KERBEROS:
	156	if (!options.kerberos_authentication) {
a306f2dd	157	verbose("Kerberos authentication disabled.");
	158	break;
	159	} else {
	160	/* Try Kerberos v4 authentication. */
	161	KTEXT_ST auth;
	162	char *tkt_user = NULL;
1e3b8b07	163	char kdata = packet_get_string((u_int ) &auth.length);
a306f2dd	164	packet_integrity_check(plen, 4 + auth.length, type);
a306f2dd	165
59c97189	166	if (authctxt->valid) {
	167	if (auth.length < MAX_KTXT_LEN)
	168	memcpy(auth.dat, kdata, auth.length);
94ec8c6b	169	authenticated = auth_krb4(pw->pw_name, &auth, &tkt_user);
94ec8c6b	170	if (authenticated) {
59c97189	171	snprintf(info, sizeof info,
59c97189	172	" tktuser %.100s", tkt_user);
94ec8c6b	173	xfree(tkt_user);
94ec8c6b	174	}
a306f2dd	175	}
59c97189	176	xfree(kdata);
a306f2dd	177	}
	178	break;
	179	#endif /* KRB4 */
	180
	181	case SSH_CMSG_AUTH_RHOSTS:
	182	if (!options.rhosts_authentication) {
	183	verbose("Rhosts authentication disabled.");
	184	break;
	185	}
	186	/*
	187	* Get client user name. Note that we just have to
	188	* trust the client; this is one reason why rhosts
	189	* authentication is insecure. (Another is
	190	* IP-spoofing on a local network.)
	191	*/
	192	client_user = packet_get_string(&ulen);
	193	packet_integrity_check(plen, 4 + ulen, type);
	194
94ec8c6b	195	/* Try to authenticate using /etc/hosts.equiv and .rhosts. */
a306f2dd	196	authenticated = auth_rhosts(pw, client_user);
a306f2dd	197
59c97189	198	snprintf(info, sizeof info, " ruser %.100s", client_user);
a306f2dd	199	break;
	200
	201	case SSH_CMSG_AUTH_RHOSTS_RSA:
	202	if (!options.rhosts_rsa_authentication) {
	203	verbose("Rhosts with RSA authentication disabled.");
	204	break;
	205	}
	206	/*
	207	* Get client user name. Note that we just have to
	208	* trust the client; root on the client machine can
	209	* claim to be any user.
	210	*/
	211	client_user = packet_get_string(&ulen);
	212
	213	/* Get the client host key. */
	214	client_host_key = RSA_new();
	215	if (client_host_key == NULL)
	216	fatal("RSA_new failed");
	217	client_host_key->e = BN_new();
	218	client_host_key->n = BN_new();
	219	if (client_host_key->e == NULL \|\| client_host_key->n == NULL)
	220	fatal("BN_new failed");
	221	bits = packet_get_int();
	222	packet_get_bignum(client_host_key->e, &elen);
	223	packet_get_bignum(client_host_key->n, &nlen);
	224
	225	if (bits != BN_num_bits(client_host_key->n))
94ec8c6b	226	verbose("Warning: keysize mismatch for client_host_key: "
0b242b12	227	"actual %d, announced %d", BN_num_bits(client_host_key->n), bits);
a306f2dd	228	packet_integrity_check(plen, (4 + ulen) + 4 + elen + nlen, type);
	229
	230	authenticated = auth_rhosts_rsa(pw, client_user, client_host_key);
	231	RSA_free(client_host_key);
	232
59c97189	233	snprintf(info, sizeof info, " ruser %.100s", client_user);
a306f2dd	234	break;
	235
	236	case SSH_CMSG_AUTH_RSA:
	237	if (!options.rsa_authentication) {
	238	verbose("RSA authentication disabled.");
	239	break;
	240	}
	241	/* RSA authentication requested. */
	242	n = BN_new();
	243	packet_get_bignum(n, &nlen);
	244	packet_integrity_check(plen, nlen, type);
	245	authenticated = auth_rsa(pw, n);
	246	BN_clear_free(n);
	247	break;
	248
	249	case SSH_CMSG_AUTH_PASSWORD:
	250	if (!options.password_authentication) {
	251	verbose("Password authentication disabled.");
	252	break;
	253	}
	254	/*
	255	* Read user password. It is in plain text, but was
	256	* transmitted over the encrypted channel so it is
	257	* not visible to an outside observer.
	258	*/
	259	password = packet_get_string(&dlen);
	260	packet_integrity_check(plen, 4 + dlen, type);
	261
	262	#ifdef USE_PAM
	263	/* Do PAM auth with password */
	264	authenticated = auth_pam_password(pw, password);
4d33e531	265	#elif defined(HAVE_OSF_SIA)
4d33e531	266	/* Do SIA auth with password */
4d33e531	267	if (sia_validate_user(NULL, saved_argc, saved_argv,
	268	get_canonical_hostname(), pw->pw_name, NULL, 0,
	269	NULL, password) == SIASUCCESS) {
	270	authenticated = 1;
	271	}
	272	#else /* !USE_PAM && !HAVE_OSF_SIA */
94ec8c6b	273	/* Try authentication with the password. */
a306f2dd	274	authenticated = auth_password(pw, password);
	275	#endif /* USE_PAM */
	276
	277	memset(password, 0, strlen(password));
	278	xfree(password);
	279	break;
	280
59c97189	281	#ifdef SKEY /* ISSUE: Is this right? we don't define
	282	having skey_authentication in
	283	servconf.h by default so I assume
	284	we need to deal with this via #ifdef
	285	in some reasonable way */
a306f2dd	286	case SSH_CMSG_AUTH_TIS:
	287	debug("rcvd SSH_CMSG_AUTH_TIS");
	288	if (options.skey_authentication == 1) {
59c97189	289	char *challenge = get_challenge(authctxt, authctxt->style);
	290	if (challenge != NULL) {
	291	debug("sending challenge '%s'", challenge);
a306f2dd	292	packet_start(SSH_SMSG_AUTH_TIS_CHALLENGE);
59c97189	293	packet_put_cstring(challenge);
a306f2dd	294	packet_send();
	295	packet_write_wait();
	296	continue;
	297	}
	298	}
	299	break;
	300	case SSH_CMSG_AUTH_TIS_RESPONSE:
	301	debug("rcvd SSH_CMSG_AUTH_TIS_RESPONSE");
	302	if (options.skey_authentication == 1) {
	303	char *response = packet_get_string(&dlen);
59c97189	304	debug("got response '%s'", response);
a306f2dd	305	packet_integrity_check(plen, 4 + dlen, type);
59c97189	306	authenticated = verify_response(authctxt, response);
59c97189	307	memset(response, 'r', dlen);
a306f2dd	308	xfree(response);
	309	}
	310	break;
59c97189	311	#endif /* ISSUE: End of wrong SKEY defines */
a306f2dd	312
	313	default:
	314	/*
	315	* Any unknown messages will be ignored (and failure
	316	* returned) during authentication.
	317	*/
	318	log("Unknown message during authentication: type %d", type);
	319	break;
	320	}
59c97189	321	if (!authctxt->valid && authenticated)
	322	fatal("INTERNAL ERROR: authenticated invalid user %s",
	323	authctxt->user);
a306f2dd	324
59c97189	325	#ifdef HAVE_CYGWIN /* ISSUE: Right place? */
94ec8c6b	326	if (authenticated &&
9cd45ea4	327	!check_nt_auth(type == SSH_CMSG_AUTH_PASSWORD,pw->pw_uid)) {
3c62e7eb	328	packet_disconnect("Authentication rejected for uid %d.",
94ec8c6b	329	(int)pw->pw_uid);
3c62e7eb	330	authenticated = 0;
	331	}
	332	#endif
	333
59c97189	334	/* Special handling for root */
	335	if (authenticated && authctxt->pw->pw_uid == 0 && !auth_root_allowed())
	336	authenticated = 0;
a306f2dd	337
59c97189	338	#ifdef USE_PAM /* ISSUE: Right place? */
94ec8c6b	339	if (authenticated && !do_pam_account(pw->pw_name, client_user))
	340	authenticated = 0;
	341	#endif
a306f2dd	342
59c97189	343	/* Log before sending the reply */
	344	auth_log(authctxt, authenticated, get_authname(type), info);
	345
a306f2dd	346	if (client_user != NULL) {
	347	xfree(client_user);
	348	client_user = NULL;
	349	}
	350
94ec8c6b	351	if (authenticated)
	352	return;
	353
59c97189	354	if (authctxt->failures++ > AUTH_FAIL_MAX) {
c1ef8333	355	#ifdef WITH_AIXAUTHENTICATE
94ec8c6b	356	loginfailed(user,get_canonical_hostname(),"ssh");
c1ef8333	357	#endif /* WITH_AIXAUTHENTICATE */
59c97189	358	packet_disconnect(AUTH_FAIL_MSG, authctxt->user);
c1ef8333	359	}
a306f2dd	360
a306f2dd	361	packet_start(SSH_SMSG_FAILURE);
	362	packet_send();
	363	packet_write_wait();
	364	}
	365	}
	366
	367	/*
	368	* Performs authentication of an incoming connection. Session key has already
	369	* been exchanged and encryption is enabled.
	370	*/
	371	void
	372	do_authentication()
	373	{
59c97189	374	Authctxt *authctxt;
59c97189	375	struct passwd *pw;
a306f2dd	376	int plen;
1e3b8b07	377	u_int ulen;
59c97189	378	char user, style = NULL;
a306f2dd	379
	380	/* Get the name of the user that we wish to log in as. */
	381	packet_read_expect(&plen, SSH_CMSG_USER);
	382
	383	/* Get the user name. */
	384	user = packet_get_string(&ulen);
	385	packet_integrity_check(plen, (4 + ulen), SSH_CMSG_USER);
	386
59c97189	387	if ((style = strchr(user, ':')) != NULL)
	388	*style++ = 0;
	389
	390	authctxt = authctxt_new();
	391	authctxt->user = user;
	392	authctxt->style = style;
	393
a306f2dd	394	setproctitle("%s", user);
	395
	396	#ifdef AFS
	397	/* If machine has AFS, set process authentication group. */
	398	if (k_hasafs()) {
	399	k_setpag();
	400	k_unlog();
	401	}
	402	#endif /* AFS */
	403
	404	/* Verify that the user is a valid user. */
	405	pw = getpwnam(user);
94ec8c6b	406	if (pw && allowed_user(pw)) {
59c97189	407	authctxt->valid = 1;
59c97189	408	pw = pwcopy(pw);
94ec8c6b	409	} else {
59c97189	410	debug("do_authentication: illegal user %s", user);
94ec8c6b	411	pw = NULL;
94ec8c6b	412	}
59c97189	413	authctxt->pw = pw;
a306f2dd	414
a306f2dd	415	#ifdef USE_PAM
94ec8c6b	416	if (pw)
04fc7a67	417	start_pam(user);
a306f2dd	418	#endif
	419
	420	/*
	421	* If we are not running as root, the user must have the same uid as
94ec8c6b	422	* the server. (Unless you are running Windows)
a306f2dd	423	*/
94ec8c6b	424	#ifndef HAVE_CYGWIN
94ec8c6b	425	if (getuid() != 0 && pw && pw->pw_uid != getuid())
a306f2dd	426	packet_disconnect("Cannot change user when server not running as root.");
3c62e7eb	427	#endif
a306f2dd	428
59c97189	429	/*
	430	* Loop until the user has been authenticated or the connection is
	431	* closed, do_authloop() returns only if authentication is successful
	432	*/
	433	do_authloop(authctxt);
a306f2dd	434
a306f2dd	435	/* The user has been authenticated and accepted. */
94ec8c6b	436	packet_start(SSH_SMSG_SUCCESS);
	437	packet_send();
	438	packet_write_wait();
59c97189	439
a306f2dd	440	#ifdef WITH_AIXAUTHENTICATE
c1ef8333	441	/* We don't have a pty yet, so just label the line as "ssh" */
59c97189	442	if (loginsuccess(authctxt->user,get_canonical_hostname(),"ssh",&aixloginmsg) < 0)
c1ef8333	443	aixloginmsg = NULL;
a306f2dd	444	#endif /* WITH_AIXAUTHENTICATE */
59c97189	445
	446	xfree(authctxt->user);
	447	xfree(authctxt);
a306f2dd	448
	449	/* Perform session preparation. */
	450	do_authenticated(pw);
	451	}