ssh-add.c - platform/external/openssh - Gitiles

 /* $OpenBSD: ssh-add.c,v 1.109 2014/02/02 03:44:31 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
  *                    All rights reserved
  * Adds an identity to the authentication server, or removes an identity.
  *
  * 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".
  *
  * SSH2 implementation,
  * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */

 #include "includes.h"

 #include <sys/types.h>
 #include <sys/stat.h>
 #include <sys/param.h>

 #include <openssl/evp.h>
 #include "openbsd-compat/openssl-compat.h"

 #include <fcntl.h>
 #include <pwd.h>
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>

 #include "xmalloc.h"
 #include "ssh.h"
 #include "rsa.h"
 #include "log.h"
 #include "key.h"
 #include "buffer.h"
 #include "authfd.h"
 #include "authfile.h"
 #include "pathnames.h"
 #include "misc.h"

 /* argv0 */
 extern char *__progname;

 /* Default files to add */
 static char *default_files[] = {
 	_PATH_SSH_CLIENT_ID_RSA,
 	_PATH_SSH_CLIENT_ID_DSA,
 #ifdef OPENSSL_HAS_ECC
 	_PATH_SSH_CLIENT_ID_ECDSA,
 #endif
 	_PATH_SSH_CLIENT_ID_ED25519,
 	_PATH_SSH_CLIENT_IDENTITY,
 	NULL
 };

 /* Default lifetime (0 == forever) */
 static int lifetime = 0;

 /* User has to confirm key use */
 static int confirm = 0;

 /* we keep a cache of one passphrases */
 static char *pass = NULL;
 static void
 clear_pass(void)
 {
 	if (pass) {
 		explicit_bzero(pass, strlen(pass));
 		free(pass);
 		pass = NULL;
 	}
 }

 static int
 delete_file(AuthenticationConnection *ac, const char *filename, int key_only)
 {
 	Key *public = NULL, *cert = NULL;
 	char *certpath = NULL, *comment = NULL;
 	int ret = -1;

 	public = key_load_public(filename, &comment);
 	if (public == NULL) {
 		printf("Bad key file %s\n", filename);
 		return -1;
 	}
 	if (ssh_remove_identity(ac, public)) {
 		fprintf(stderr, "Identity removed: %s (%s)\n", filename, comment);
 		ret = 0;
 	} else
 		fprintf(stderr, "Could not remove identity: %s\n", filename);

 	if (key_only)
 		goto out;

 	/* Now try to delete the corresponding certificate too */
 	free(comment);
 	comment = NULL;
 	xasprintf(&certpath, "%s-cert.pub", filename);
 	if ((cert = key_load_public(certpath, &comment)) == NULL)
 		goto out;
 	if (!key_equal_public(cert, public))
 		fatal("Certificate %s does not match private key %s",
 		    certpath, filename);

 	if (ssh_remove_identity(ac, cert)) {
 		fprintf(stderr, "Identity removed: %s (%s)\n", certpath,
 		    comment);
 		ret = 0;
 	} else
 		fprintf(stderr, "Could not remove identity: %s\n", certpath);

  out:
 	if (cert != NULL)
 		key_free(cert);
 	if (public != NULL)
 		key_free(public);
 	free(certpath);
 	free(comment);

 	return ret;
 }

 /* Send a request to remove all identities. */
 static int
 delete_all(AuthenticationConnection *ac)
 {
 	int ret = -1;

 	if (ssh_remove_all_identities(ac, 1))
 		ret = 0;
 	/* ignore error-code for ssh2 */
 	ssh_remove_all_identities(ac, 2);

 	if (ret == 0)
 		fprintf(stderr, "All identities removed.\n");
 	else
 		fprintf(stderr, "Failed to remove all identities.\n");

 	return ret;
 }

 static int
 add_file(AuthenticationConnection *ac, const char *filename, int key_only)
 {
 	Key *private, *cert;
 	char *comment = NULL;
 	char msg[1024], *certpath = NULL;
 	int fd, perms_ok, ret = -1;
 	Buffer keyblob;

 	if (strcmp(filename, "-") == 0) {
 		fd = STDIN_FILENO;
 		filename = "(stdin)";
 	} else if ((fd = open(filename, O_RDONLY)) < 0) {
 		perror(filename);
 		return -1;
 	}

 	/*
 	 * Since we'll try to load a keyfile multiple times, permission errors
 	 * will occur multiple times, so check perms first and bail if wrong.
 	 */
 	if (fd != STDIN_FILENO) {
 		perms_ok = key_perm_ok(fd, filename);
 		if (!perms_ok) {
 			close(fd);
 			return -1;
 		}
 	}
 	buffer_init(&keyblob);
 	if (!key_load_file(fd, filename, &keyblob)) {
 		buffer_free(&keyblob);
 		close(fd);
 		return -1;
 	}
 	close(fd);

 	/* At first, try empty passphrase */
 	private = key_parse_private(&keyblob, filename, "", &comment);
 	if (comment == NULL)
 		comment = xstrdup(filename);
 	/* try last */
 	if (private == NULL && pass != NULL)
 		private = key_parse_private(&keyblob, filename, pass, NULL);
 	if (private == NULL) {
 		/* clear passphrase since it did not work */
 		clear_pass();
 		snprintf(msg, sizeof msg, "Enter passphrase for %.200s: ",
 		    comment);
 		for (;;) {
 			pass = read_passphrase(msg, RP_ALLOW_STDIN);
 			if (strcmp(pass, "") == 0) {
 				clear_pass();
 				free(comment);
 				buffer_free(&keyblob);
 				return -1;
 			}
 			private = key_parse_private(&keyblob, filename, pass,
 			    &comment);
 			if (private != NULL)
 				break;
 			clear_pass();
 			snprintf(msg, sizeof msg,
 			    "Bad passphrase, try again for %.200s: ", comment);
 		}
 	}
 	buffer_free(&keyblob);

 	if (ssh_add_identity_constrained(ac, private, comment, lifetime,
 	    confirm)) {
 		fprintf(stderr, "Identity added: %s (%s)\n", filename, comment);
 		ret = 0;
 		if (lifetime != 0)
 			fprintf(stderr,
 			    "Lifetime set to %d seconds\n", lifetime);
 		if (confirm != 0)
 			fprintf(stderr,
 			    "The user must confirm each use of the key\n");
 	} else {
 		fprintf(stderr, "Could not add identity: %s\n", filename);
 	}

 	/* Skip trying to load the cert if requested */
 	if (key_only)
 		goto out;

 	/* Now try to add the certificate flavour too */
 	xasprintf(&certpath, "%s-cert.pub", filename);
 	if ((cert = key_load_public(certpath, NULL)) == NULL)
 		goto out;

 	if (!key_equal_public(cert, private)) {
 		error("Certificate %s does not match private key %s",
 		    certpath, filename);
 		key_free(cert);
 		goto out;
 	}

 	/* Graft with private bits */
 	if (key_to_certified(private, key_cert_is_legacy(cert)) != 0) {
 		error("%s: key_to_certified failed", __func__);
 		key_free(cert);
 		goto out;
 	}
 	key_cert_copy(cert, private);
 	key_free(cert);

 	if (!ssh_add_identity_constrained(ac, private, comment,
 	    lifetime, confirm)) {
 		error("Certificate %s (%s) add failed", certpath,
 		    private->cert->key_id);
 	}
 	fprintf(stderr, "Certificate added: %s (%s)\n", certpath,
 	    private->cert->key_id);
 	if (lifetime != 0)
 		fprintf(stderr, "Lifetime set to %d seconds\n", lifetime);
 	if (confirm != 0)
 		fprintf(stderr, "The user must confirm each use of the key\n");
  out:
 	if (certpath != NULL)
 		free(certpath);
 	free(comment);
 	key_free(private);

 	return ret;
 }

 static int
 update_card(AuthenticationConnection *ac, int add, const char *id)
 {
 	char *pin = NULL;
 	int ret = -1;

 	if (add) {
 		if ((pin = read_passphrase("Enter passphrase for PKCS#11: ",
 		    RP_ALLOW_STDIN)) == NULL)
 			return -1;
 	}

 	if (ssh_update_card(ac, add, id, pin == NULL ? "" : pin,
 	    lifetime, confirm)) {
 		fprintf(stderr, "Card %s: %s\n",
 		    add ? "added" : "removed", id);
 		ret = 0;
 	} else {
 		fprintf(stderr, "Could not %s card: %s\n",
 		    add ? "add" : "remove", id);
 		ret = -1;
 	}
 	free(pin);
 	return ret;
 }

 static int
 list_identities(AuthenticationConnection *ac, int do_fp)
 {
 	Key *key;
 	char *comment, *fp;
 	int had_identities = 0;
 	int version;

 	for (version = 1; version <= 2; version++) {
 		for (key = ssh_get_first_identity(ac, &comment, version);
 		    key != NULL;
 		    key = ssh_get_next_identity(ac, &comment, version)) {
 			had_identities = 1;
 			if (do_fp) {
 				fp = key_fingerprint(key, SSH_FP_MD5,
 				    SSH_FP_HEX);
 				printf("%d %s %s (%s)\n",
 				    key_size(key), fp, comment, key_type(key));
 				free(fp);
 			} else {
 				if (!key_write(key, stdout))
 					fprintf(stderr, "key_write failed");
 				fprintf(stdout, " %s\n", comment);
 			}
 			key_free(key);
 			free(comment);
 		}
 	}
 	if (!had_identities) {
 		printf("The agent has no identities.\n");
 		return -1;
 	}
 	return 0;
 }

 static int
 lock_agent(AuthenticationConnection *ac, int lock)
 {
 	char prompt[100], *p1, *p2;
 	int passok = 1, ret = -1;

 	strlcpy(prompt, "Enter lock password: ", sizeof(prompt));
 	p1 = read_passphrase(prompt, RP_ALLOW_STDIN);
 	if (lock) {
 		strlcpy(prompt, "Again: ", sizeof prompt);
 		p2 = read_passphrase(prompt, RP_ALLOW_STDIN);
 		if (strcmp(p1, p2) != 0) {
 			fprintf(stderr, "Passwords do not match.\n");
 			passok = 0;
 		}
 		explicit_bzero(p2, strlen(p2));
 		free(p2);
 	}
 	if (passok && ssh_lock_agent(ac, lock, p1)) {
 		fprintf(stderr, "Agent %slocked.\n", lock ? "" : "un");
 		ret = 0;
 	} else
 		fprintf(stderr, "Failed to %slock agent.\n", lock ? "" : "un");
 	explicit_bzero(p1, strlen(p1));
 	free(p1);
 	return (ret);
 }

 static int
 do_file(AuthenticationConnection *ac, int deleting, int key_only, char *file)
 {
 	if (deleting) {
 		if (delete_file(ac, file, key_only) == -1)
 			return -1;
 	} else {
 		if (add_file(ac, file, key_only) == -1)
 			return -1;
 	}
 	return 0;
 }

 static void
 usage(void)
 {
 	fprintf(stderr, "usage: %s [options] [file ...]\n", __progname);
 	fprintf(stderr, "Options:\n");
 	fprintf(stderr, "  -l          List fingerprints of all identities.\n");
 	fprintf(stderr, "  -L          List public key parameters of all identities.\n");
 	fprintf(stderr, "  -k          Load only keys and not certificates.\n");
 	fprintf(stderr, "  -c          Require confirmation to sign using identities\n");
 	fprintf(stderr, "  -t life     Set lifetime (in seconds) when adding identities.\n");
 	fprintf(stderr, "  -d          Delete identity.\n");
 	fprintf(stderr, "  -D          Delete all identities.\n");
 	fprintf(stderr, "  -x          Lock agent.\n");
 	fprintf(stderr, "  -X          Unlock agent.\n");
 	fprintf(stderr, "  -s pkcs11   Add keys from PKCS#11 provider.\n");
 	fprintf(stderr, "  -e pkcs11   Remove keys provided by PKCS#11 provider.\n");
 }

 int
 main(int argc, char **argv)
 {
 	extern char *optarg;
 	extern int optind;
 	AuthenticationConnection *ac = NULL;
 	char *pkcs11provider = NULL;
 	int i, ch, deleting = 0, ret = 0, key_only = 0;

 	/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
 	sanitise_stdfd();

 	__progname = ssh_get_progname(argv[0]);
 	seed_rng();

 	OpenSSL_add_all_algorithms();

 	/* At first, get a connection to the authentication agent. */
 	ac = ssh_get_authentication_connection();
 	if (ac == NULL) {
 		fprintf(stderr,
 		    "Could not open a connection to your authentication agent.\n");
 		exit(2);
 	}
 	while ((ch = getopt(argc, argv, "klLcdDxXe:s:t:")) != -1) {
 		switch (ch) {
 		case 'k':
 			key_only = 1;
 			break;
 		case 'l':
 		case 'L':
 			if (list_identities(ac, ch == 'l' ? 1 : 0) == -1)
 				ret = 1;
 			goto done;
 		case 'x':
 		case 'X':
 			if (lock_agent(ac, ch == 'x' ? 1 : 0) == -1)
 				ret = 1;
 			goto done;
 		case 'c':
 			confirm = 1;
 			break;
 		case 'd':
 			deleting = 1;
 			break;
 		case 'D':
 			if (delete_all(ac) == -1)
 				ret = 1;
 			goto done;
 		case 's':
 			pkcs11provider = optarg;
 			break;
 		case 'e':
 			deleting = 1;
 			pkcs11provider = optarg;
 			break;
 		case 't':
 			if ((lifetime = convtime(optarg)) == -1) {
 				fprintf(stderr, "Invalid lifetime\n");
 				ret = 1;
 				goto done;
 			}
 			break;
 		default:
 			usage();
 			ret = 1;
 			goto done;
 		}
 	}
 	argc -= optind;
 	argv += optind;
 	if (pkcs11provider != NULL) {
 		if (update_card(ac, !deleting, pkcs11provider) == -1)
 			ret = 1;
 		goto done;
 	}
 	if (argc == 0) {
 		char buf[MAXPATHLEN];
 		struct passwd *pw;
 		struct stat st;
 		int count = 0;

 		if ((pw = getpwuid(getuid())) == NULL) {
 			fprintf(stderr, "No user found with uid %u\n",
 			    (u_int)getuid());
 			ret = 1;
 			goto done;
 		}

 		for (i = 0; default_files[i]; i++) {
 			snprintf(buf, sizeof(buf), "%s/%s", pw->pw_dir,
 			    default_files[i]);
 			if (stat(buf, &st) < 0)
 				continue;
 			if (do_file(ac, deleting, key_only, buf) == -1)
 				ret = 1;
 			else
 				count++;
 		}
 		if (count == 0)
 			ret = 1;
 	} else {
 		for (i = 0; i < argc; i++) {
 			if (do_file(ac, deleting, key_only, argv[i]) == -1)
 				ret = 1;
 		}
 	}
 	clear_pass();

 done:
 	ssh_close_authentication_connection(ac);
 	return ret;
 }
	/* $OpenBSD: ssh-add.c,v 1.109 2014/02/02 03:44:31 djm Exp $ */
	/*
	* Author: Tatu Ylonen <ylo@cs.hut.fi>
	* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
	* All rights reserved
	* Adds an identity to the authentication server, or removes an identity.
	*
	* 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".
	*
	* SSH2 implementation,
	* Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	*
	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#include "includes.h"

	#include <sys/types.h>
	#include <sys/stat.h>
	#include <sys/param.h>

	#include <openssl/evp.h>
	#include "openbsd-compat/openssl-compat.h"

	#include <fcntl.h>
	#include <pwd.h>
	#include <stdarg.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include <unistd.h>

	#include "xmalloc.h"
	#include "ssh.h"
	#include "rsa.h"
	#include "log.h"
	#include "key.h"
	#include "buffer.h"
	#include "authfd.h"
	#include "authfile.h"
	#include "pathnames.h"
	#include "misc.h"

	/* argv0 */
	extern char *__progname;

	/* Default files to add */
	static char *default_files[] = {
	_PATH_SSH_CLIENT_ID_RSA,
	_PATH_SSH_CLIENT_ID_DSA,
	#ifdef OPENSSL_HAS_ECC
	_PATH_SSH_CLIENT_ID_ECDSA,
	#endif
	_PATH_SSH_CLIENT_ID_ED25519,
	_PATH_SSH_CLIENT_IDENTITY,
	NULL
	};

	/* Default lifetime (0 == forever) */
	static int lifetime = 0;

	/* User has to confirm key use */
	static int confirm = 0;

	/* we keep a cache of one passphrases */
	static char *pass = NULL;
	static void
	clear_pass(void)
	{
	if (pass) {
	explicit_bzero(pass, strlen(pass));
	free(pass);
	pass = NULL;
	}
	}

	static int
	delete_file(AuthenticationConnection ac, const char filename, int key_only)
	{
	Key public = NULL, cert = NULL;
	char certpath = NULL, comment = NULL;
	int ret = -1;

	public = key_load_public(filename, &comment);
	if (public == NULL) {
	printf("Bad key file %s\n", filename);
	return -1;
	}
	if (ssh_remove_identity(ac, public)) {
	fprintf(stderr, "Identity removed: %s (%s)\n", filename, comment);
	ret = 0;
	} else
	fprintf(stderr, "Could not remove identity: %s\n", filename);

	if (key_only)
	goto out;

	/* Now try to delete the corresponding certificate too */
	free(comment);
	comment = NULL;
	xasprintf(&certpath, "%s-cert.pub", filename);
	if ((cert = key_load_public(certpath, &comment)) == NULL)
	goto out;
	if (!key_equal_public(cert, public))
	fatal("Certificate %s does not match private key %s",
	certpath, filename);

	if (ssh_remove_identity(ac, cert)) {
	fprintf(stderr, "Identity removed: %s (%s)\n", certpath,
	comment);
	ret = 0;
	} else
	fprintf(stderr, "Could not remove identity: %s\n", certpath);

	out:
	if (cert != NULL)
	key_free(cert);
	if (public != NULL)
	key_free(public);
	free(certpath);
	free(comment);

	return ret;
	}

	/* Send a request to remove all identities. */
	static int
	delete_all(AuthenticationConnection *ac)
	{
	int ret = -1;

	if (ssh_remove_all_identities(ac, 1))
	ret = 0;
	/* ignore error-code for ssh2 */
	ssh_remove_all_identities(ac, 2);

	if (ret == 0)
	fprintf(stderr, "All identities removed.\n");
	else
	fprintf(stderr, "Failed to remove all identities.\n");

	return ret;
	}

	static int
	add_file(AuthenticationConnection ac, const char filename, int key_only)
	{
	Key private, cert;
	char *comment = NULL;
	char msg[1024], *certpath = NULL;
	int fd, perms_ok, ret = -1;
	Buffer keyblob;

	if (strcmp(filename, "-") == 0) {
	fd = STDIN_FILENO;
	filename = "(stdin)";
	} else if ((fd = open(filename, O_RDONLY)) < 0) {
	perror(filename);
	return -1;
	}

	/*
	* Since we'll try to load a keyfile multiple times, permission errors
	* will occur multiple times, so check perms first and bail if wrong.
	*/
	if (fd != STDIN_FILENO) {
	perms_ok = key_perm_ok(fd, filename);
	if (!perms_ok) {
	close(fd);
	return -1;
	}
	}
	buffer_init(&keyblob);
	if (!key_load_file(fd, filename, &keyblob)) {
	buffer_free(&keyblob);
	close(fd);
	return -1;
	}
	close(fd);

	/* At first, try empty passphrase */
	private = key_parse_private(&keyblob, filename, "", &comment);
	if (comment == NULL)
	comment = xstrdup(filename);
	/* try last */
	if (private == NULL && pass != NULL)
	private = key_parse_private(&keyblob, filename, pass, NULL);
	if (private == NULL) {
	/* clear passphrase since it did not work */
	clear_pass();
	snprintf(msg, sizeof msg, "Enter passphrase for %.200s: ",
	comment);
	for (;;) {
	pass = read_passphrase(msg, RP_ALLOW_STDIN);
	if (strcmp(pass, "") == 0) {
	clear_pass();
	free(comment);
	buffer_free(&keyblob);
	return -1;
	}
	private = key_parse_private(&keyblob, filename, pass,
	&comment);
	if (private != NULL)
	break;
	clear_pass();
	snprintf(msg, sizeof msg,
	"Bad passphrase, try again for %.200s: ", comment);
	}
	}
	buffer_free(&keyblob);

	if (ssh_add_identity_constrained(ac, private, comment, lifetime,
	confirm)) {
	fprintf(stderr, "Identity added: %s (%s)\n", filename, comment);
	ret = 0;
	if (lifetime != 0)
	fprintf(stderr,
	"Lifetime set to %d seconds\n", lifetime);
	if (confirm != 0)
	fprintf(stderr,
	"The user must confirm each use of the key\n");
	} else {
	fprintf(stderr, "Could not add identity: %s\n", filename);
	}

	/* Skip trying to load the cert if requested */
	if (key_only)
	goto out;

	/* Now try to add the certificate flavour too */
	xasprintf(&certpath, "%s-cert.pub", filename);
	if ((cert = key_load_public(certpath, NULL)) == NULL)
	goto out;

	if (!key_equal_public(cert, private)) {
	error("Certificate %s does not match private key %s",
	certpath, filename);
	key_free(cert);
	goto out;
	}

	/* Graft with private bits */
	if (key_to_certified(private, key_cert_is_legacy(cert)) != 0) {
	error("%s: key_to_certified failed", __func__);
	key_free(cert);
	goto out;
	}
	key_cert_copy(cert, private);
	key_free(cert);

	if (!ssh_add_identity_constrained(ac, private, comment,
	lifetime, confirm)) {
	error("Certificate %s (%s) add failed", certpath,
	private->cert->key_id);
	}
	fprintf(stderr, "Certificate added: %s (%s)\n", certpath,
	private->cert->key_id);
	if (lifetime != 0)
	fprintf(stderr, "Lifetime set to %d seconds\n", lifetime);
	if (confirm != 0)
	fprintf(stderr, "The user must confirm each use of the key\n");
	out:
	if (certpath != NULL)
	free(certpath);
	free(comment);
	key_free(private);

	return ret;
	}

	static int
	update_card(AuthenticationConnection ac, int add, const char id)
	{
	char *pin = NULL;
	int ret = -1;

	if (add) {
	if ((pin = read_passphrase("Enter passphrase for PKCS#11: ",
	RP_ALLOW_STDIN)) == NULL)
	return -1;
	}

	if (ssh_update_card(ac, add, id, pin == NULL ? "" : pin,
	lifetime, confirm)) {
	fprintf(stderr, "Card %s: %s\n",
	add ? "added" : "removed", id);
	ret = 0;
	} else {
	fprintf(stderr, "Could not %s card: %s\n",
	add ? "add" : "remove", id);
	ret = -1;
	}
	free(pin);
	return ret;
	}

	static int
	list_identities(AuthenticationConnection *ac, int do_fp)
	{
	Key *key;
	char comment, fp;
	int had_identities = 0;
	int version;

	for (version = 1; version <= 2; version++) {
	for (key = ssh_get_first_identity(ac, &comment, version);
	key != NULL;
	key = ssh_get_next_identity(ac, &comment, version)) {
	had_identities = 1;
	if (do_fp) {
	fp = key_fingerprint(key, SSH_FP_MD5,
	SSH_FP_HEX);
	printf("%d %s %s (%s)\n",
	key_size(key), fp, comment, key_type(key));
	free(fp);
	} else {
	if (!key_write(key, stdout))
	fprintf(stderr, "key_write failed");
	fprintf(stdout, " %s\n", comment);
	}
	key_free(key);
	free(comment);
	}
	}
	if (!had_identities) {
	printf("The agent has no identities.\n");
	return -1;
	}
	return 0;
	}

	static int
	lock_agent(AuthenticationConnection *ac, int lock)
	{
	char prompt[100], p1, p2;
	int passok = 1, ret = -1;

	strlcpy(prompt, "Enter lock password: ", sizeof(prompt));
	p1 = read_passphrase(prompt, RP_ALLOW_STDIN);
	if (lock) {
	strlcpy(prompt, "Again: ", sizeof prompt);
	p2 = read_passphrase(prompt, RP_ALLOW_STDIN);
	if (strcmp(p1, p2) != 0) {
	fprintf(stderr, "Passwords do not match.\n");
	passok = 0;
	}
	explicit_bzero(p2, strlen(p2));
	free(p2);
	}
	if (passok && ssh_lock_agent(ac, lock, p1)) {
	fprintf(stderr, "Agent %slocked.\n", lock ? "" : "un");
	ret = 0;
	} else
	fprintf(stderr, "Failed to %slock agent.\n", lock ? "" : "un");
	explicit_bzero(p1, strlen(p1));
	free(p1);
	return (ret);
	}

	static int
	do_file(AuthenticationConnection ac, int deleting, int key_only, char file)
	{
	if (deleting) {
	if (delete_file(ac, file, key_only) == -1)
	return -1;
	} else {
	if (add_file(ac, file, key_only) == -1)
	return -1;
	}
	return 0;
	}

	static void
	usage(void)
	{
	fprintf(stderr, "usage: %s [options] [file ...]\n", __progname);
	fprintf(stderr, "Options:\n");
	fprintf(stderr, " -l List fingerprints of all identities.\n");
	fprintf(stderr, " -L List public key parameters of all identities.\n");
	fprintf(stderr, " -k Load only keys and not certificates.\n");
	fprintf(stderr, " -c Require confirmation to sign using identities\n");
	fprintf(stderr, " -t life Set lifetime (in seconds) when adding identities.\n");
	fprintf(stderr, " -d Delete identity.\n");
	fprintf(stderr, " -D Delete all identities.\n");
	fprintf(stderr, " -x Lock agent.\n");
	fprintf(stderr, " -X Unlock agent.\n");
	fprintf(stderr, " -s pkcs11 Add keys from PKCS#11 provider.\n");
	fprintf(stderr, " -e pkcs11 Remove keys provided by PKCS#11 provider.\n");
	}

	int
	main(int argc, char **argv)
	{
	extern char *optarg;
	extern int optind;
	AuthenticationConnection *ac = NULL;
	char *pkcs11provider = NULL;
	int i, ch, deleting = 0, ret = 0, key_only = 0;

	/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
	sanitise_stdfd();

	__progname = ssh_get_progname(argv[0]);
	seed_rng();

	OpenSSL_add_all_algorithms();

	/* At first, get a connection to the authentication agent. */
	ac = ssh_get_authentication_connection();
	if (ac == NULL) {
	fprintf(stderr,
	"Could not open a connection to your authentication agent.\n");
	exit(2);
	}
	while ((ch = getopt(argc, argv, "klLcdDxXe:s:t:")) != -1) {
	switch (ch) {
	case 'k':
	key_only = 1;
	break;
	case 'l':
	case 'L':
	if (list_identities(ac, ch == 'l' ? 1 : 0) == -1)
	ret = 1;
	goto done;
	case 'x':
	case 'X':
	if (lock_agent(ac, ch == 'x' ? 1 : 0) == -1)
	ret = 1;
	goto done;
	case 'c':
	confirm = 1;
	break;
	case 'd':
	deleting = 1;
	break;
	case 'D':
	if (delete_all(ac) == -1)
	ret = 1;
	goto done;
	case 's':
	pkcs11provider = optarg;
	break;
	case 'e':
	deleting = 1;
	pkcs11provider = optarg;
	break;
	case 't':
	if ((lifetime = convtime(optarg)) == -1) {
	fprintf(stderr, "Invalid lifetime\n");
	ret = 1;
	goto done;
	}
	break;
	default:
	usage();
	ret = 1;
	goto done;
	}
	}
	argc -= optind;
	argv += optind;
	if (pkcs11provider != NULL) {
	if (update_card(ac, !deleting, pkcs11provider) == -1)
	ret = 1;
	goto done;
	}
	if (argc == 0) {
	char buf[MAXPATHLEN];
	struct passwd *pw;
	struct stat st;
	int count = 0;

	if ((pw = getpwuid(getuid())) == NULL) {
	fprintf(stderr, "No user found with uid %u\n",
	(u_int)getuid());
	ret = 1;
	goto done;
	}

	for (i = 0; default_files[i]; i++) {
	snprintf(buf, sizeof(buf), "%s/%s", pw->pw_dir,
	default_files[i]);
	if (stat(buf, &st) < 0)
	continue;
	if (do_file(ac, deleting, key_only, buf) == -1)
	ret = 1;
	else
	count++;
	}
	if (count == 0)
	ret = 1;
	} else {
	for (i = 0; i < argc; i++) {
	if (do_file(ac, deleting, key_only, argv[i]) == -1)
	ret = 1;
	}
	}
	clear_pass();

	done:
	ssh_close_authentication_connection(ac);
	return ret;
	}