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

 /* $OpenBSD: ssh-add.c,v 1.136 2018/09/19 02:03:02 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 <openssl/evp.h>
 #include "openbsd-compat/openssl-compat.h"

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

 #include "xmalloc.h"
 #include "ssh.h"
 #include "log.h"
 #include "sshkey.h"
 #include "sshbuf.h"
 #include "authfd.h"
 #include "authfile.h"
 #include "pathnames.h"
 #include "misc.h"
 #include "ssherr.h"
 #include "digest.h"

 /* argv0 */
 extern char *__progname;

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

 static int fingerprint_hash = SSH_FP_HASH_DEFAULT;

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

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

 /* Maximum number of signatures (XMSS) */
 static u_int maxsign = 0;
 static u_int minleft = 0;

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

 static int
 delete_file(int agent_fd, const char *filename, int key_only, int qflag)
 {
 	struct sshkey *public, *cert = NULL;
 	char *certpath = NULL, *comment = NULL;
 	int r, ret = -1;

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

 	if (key_only)
 		goto out;

 	/* Now try to delete the corresponding certificate too */
 	free(comment);
 	comment = NULL;
 	xasprintf(&certpath, "%s-cert.pub", filename);
 	if ((r = sshkey_load_public(certpath, &cert, &comment)) != 0) {
 		if (r != SSH_ERR_SYSTEM_ERROR || errno != ENOENT)
 			error("Failed to load certificate \"%s\": %s",
 			    certpath, ssh_err(r));
 		goto out;
 	}

 	if (!sshkey_equal_public(cert, public))
 		fatal("Certificate %s does not match private key %s",
 		    certpath, filename);

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

  out:
 	sshkey_free(cert);
 	sshkey_free(public);
 	free(certpath);
 	free(comment);

 	return ret;
 }

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

 	/*
 	 * Since the agent might be forwarded, old or non-OpenSSH, when asked
 	 * to remove all keys, attempt to remove both protocol v.1 and v.2
 	 * keys.
 	 */
 	if (ssh_remove_all_identities(agent_fd, 2) == 0)
 		ret = 0;
 	/* ignore error-code for ssh1 */
 	ssh_remove_all_identities(agent_fd, 1);

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

 	return ret;
 }

 static int
 add_file(int agent_fd, const char *filename, int key_only, int qflag)
 {
 	struct sshkey *private, *cert;
 	char *comment = NULL;
 	char msg[1024], *certpath = NULL;
 	int r, fd, ret = -1;
 	size_t i;
 	u_int32_t left;
 	struct sshbuf *keyblob;
 	struct ssh_identitylist *idlist;

 	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) {
 		if (sshkey_perm_ok(fd, filename) != 0) {
 			close(fd);
 			return -1;
 		}
 	}
 	if ((keyblob = sshbuf_new()) == NULL)
 		fatal("%s: sshbuf_new failed", __func__);
 	if ((r = sshkey_load_file(fd, keyblob)) != 0) {
 		fprintf(stderr, "Error loading key \"%s\": %s\n",
 		    filename, ssh_err(r));
 		sshbuf_free(keyblob);
 		close(fd);
 		return -1;
 	}
 	close(fd);

 	/* At first, try empty passphrase */
 	if ((r = sshkey_parse_private_fileblob(keyblob, "", &private,
 	    &comment)) != 0 && r != SSH_ERR_KEY_WRONG_PASSPHRASE) {
 		fprintf(stderr, "Error loading key \"%s\": %s\n",
 		    filename, ssh_err(r));
 		goto fail_load;
 	}
 	/* try last */
 	if (private == NULL && pass != NULL) {
 		if ((r = sshkey_parse_private_fileblob(keyblob, pass, &private,
 		    &comment)) != 0 && r != SSH_ERR_KEY_WRONG_PASSPHRASE) {
 			fprintf(stderr, "Error loading key \"%s\": %s\n",
 			    filename, ssh_err(r));
 			goto fail_load;
 		}
 	}
 	if (private == NULL) {
 		/* clear passphrase since it did not work */
 		clear_pass();
 		snprintf(msg, sizeof msg, "Enter passphrase for %s%s: ",
 		    filename, confirm ? " (will confirm each use)" : "");
 		for (;;) {
 			pass = read_passphrase(msg, RP_ALLOW_STDIN);
 			if (strcmp(pass, "") == 0)
 				goto fail_load;
 			if ((r = sshkey_parse_private_fileblob(keyblob, pass,
 			    &private, &comment)) == 0)
 				break;
 			else if (r != SSH_ERR_KEY_WRONG_PASSPHRASE) {
 				fprintf(stderr,
 				    "Error loading key \"%s\": %s\n",
 				    filename, ssh_err(r));
  fail_load:
 				clear_pass();
 				sshbuf_free(keyblob);
 				return -1;
 			}
 			clear_pass();
 			snprintf(msg, sizeof msg,
 			    "Bad passphrase, try again for %s%s: ", filename,
 			    confirm ? " (will confirm each use)" : "");
 		}
 	}
 	if (comment == NULL || *comment == '\0')
 		comment = xstrdup(filename);
 	sshbuf_free(keyblob);

 	/* For XMSS */
 	if ((r = sshkey_set_filename(private, filename)) != 0) {
 		fprintf(stderr, "Could not add filename to private key: %s (%s)\n",
 		    filename, comment);
 		goto out;
 	}
 	if (maxsign && minleft &&
 	    (r = ssh_fetch_identitylist(agent_fd, &idlist)) == 0) {
 		for (i = 0; i < idlist->nkeys; i++) {
 			if (!sshkey_equal_public(idlist->keys[i], private))
 				continue;
 			left = sshkey_signatures_left(idlist->keys[i]);
 			if (left < minleft) {
 				fprintf(stderr,
 				    "Only %d signatures left.\n", left);
 				break;
 			}
 			fprintf(stderr, "Skipping update: ");
 			if (left == minleft) {
 				fprintf(stderr,
 				   "required signatures left (%d).\n", left);
 			} else {
 				fprintf(stderr,
 				   "more signatures left (%d) than"
 				    " required (%d).\n", left, minleft);
 			}
 			ssh_free_identitylist(idlist);
 			goto out;
 		}
 		ssh_free_identitylist(idlist);
 	}

 	if ((r = ssh_add_identity_constrained(agent_fd, private, comment,
 	    lifetime, confirm, maxsign)) == 0) {
 		ret = 0;
 		if (!qflag) {
 			fprintf(stderr, "Identity added: %s (%s)\n",
 			    filename, comment);
 			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\": %s\n",
 		    filename, ssh_err(r));
 	}

 	/* 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 ((r = sshkey_load_public(certpath, &cert, NULL)) != 0) {
 		if (r != SSH_ERR_SYSTEM_ERROR || errno != ENOENT)
 			error("Failed to load certificate \"%s\": %s",
 			    certpath, ssh_err(r));
 		goto out;
 	}

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

 	/* Graft with private bits */
 	if ((r = sshkey_to_certified(private)) != 0) {
 		error("%s: sshkey_to_certified: %s", __func__, ssh_err(r));
 		sshkey_free(cert);
 		goto out;
 	}
 	if ((r = sshkey_cert_copy(cert, private)) != 0) {
 		error("%s: sshkey_cert_copy: %s", __func__, ssh_err(r));
 		sshkey_free(cert);
 		goto out;
 	}
 	sshkey_free(cert);

 	if ((r = ssh_add_identity_constrained(agent_fd, private, comment,
 	    lifetime, confirm, maxsign)) != 0) {
 		error("Certificate %s (%s) add failed: %s", certpath,
 		    private->cert->key_id, ssh_err(r));
 		goto out;
 	}
 	/* success */
 	if (!qflag) {
 		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:
 	free(certpath);
 	free(comment);
 	sshkey_free(private);

 	return ret;
 }

 static int
 update_card(int agent_fd, int add, const char *id, int qflag)
 {
 	char *pin = NULL;
 	int r, ret = -1;

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

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

 static int
 list_identities(int agent_fd, int do_fp)
 {
 	char *fp;
 	int r;
 	struct ssh_identitylist *idlist;
 	u_int32_t left;
 	size_t i;

 	if ((r = ssh_fetch_identitylist(agent_fd, &idlist)) != 0) {
 		if (r != SSH_ERR_AGENT_NO_IDENTITIES)
 			fprintf(stderr, "error fetching identities: %s\n",
 			    ssh_err(r));
 		else
 			printf("The agent has no identities.\n");
 		return -1;
 	}
 	for (i = 0; i < idlist->nkeys; i++) {
 		if (do_fp) {
 			fp = sshkey_fingerprint(idlist->keys[i],
 			    fingerprint_hash, SSH_FP_DEFAULT);
 			printf("%u %s %s (%s)\n", sshkey_size(idlist->keys[i]),
 			    fp == NULL ? "(null)" : fp, idlist->comments[i],
 			    sshkey_type(idlist->keys[i]));
 			free(fp);
 		} else {
 			if ((r = sshkey_write(idlist->keys[i], stdout)) != 0) {
 				fprintf(stderr, "sshkey_write: %s\n",
 				    ssh_err(r));
 				continue;
 			}
 			fprintf(stdout, " %s", idlist->comments[i]);
 			left = sshkey_signatures_left(idlist->keys[i]);
 			if (left > 0)
 				fprintf(stdout,
 				    " [signatures left %d]", left);
 			fprintf(stdout, "\n");
 		}
 	}
 	ssh_free_identitylist(idlist);
 	return 0;
 }

 static int
 lock_agent(int agent_fd, int lock)
 {
 	char prompt[100], *p1, *p2;
 	int r, 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) {
 		if ((r = ssh_lock_agent(agent_fd, lock, p1)) == 0) {
 			fprintf(stderr, "Agent %slocked.\n", lock ? "" : "un");
 			ret = 0;
 		} else {
 			fprintf(stderr, "Failed to %slock agent: %s\n",
 			    lock ? "" : "un", ssh_err(r));
 		}
 	}
 	explicit_bzero(p1, strlen(p1));
 	free(p1);
 	return (ret);
 }

 static int
 do_file(int agent_fd, int deleting, int key_only, char *file, int qflag)
 {
 	if (deleting) {
 		if (delete_file(agent_fd, file, key_only, qflag) == -1)
 			return -1;
 	} else {
 		if (add_file(agent_fd, file, key_only, qflag) == -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, "  -E hash     Specify hash algorithm used for fingerprints.\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, "  -m minleft  Maxsign is only changed if less than minleft are left (for XMSS)\n");
 	fprintf(stderr, "  -M maxsign  Maximum number of signatures allowed (for XMSS)\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");
 	fprintf(stderr, "  -q          Be quiet after a successful operation.\n");
 }

 int
 main(int argc, char **argv)
 {
 	extern char *optarg;
 	extern int optind;
 	int agent_fd;
 	char *pkcs11provider = NULL;
 	int r, i, ch, deleting = 0, ret = 0, key_only = 0;
 	int xflag = 0, lflag = 0, Dflag = 0, qflag = 0;

 	ssh_malloc_init();	/* must be called before any mallocs */
 	/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
 	sanitise_stdfd();

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

 	setvbuf(stdout, NULL, _IOLBF, 0);

 	/* First, get a connection to the authentication agent. */
 	switch (r = ssh_get_authentication_socket(&agent_fd)) {
 	case 0:
 		break;
 	case SSH_ERR_AGENT_NOT_PRESENT:
 		fprintf(stderr, "Could not open a connection to your "
 		    "authentication agent.\n");
 		exit(2);
 	default:
 		fprintf(stderr, "Error connecting to agent: %s\n", ssh_err(r));
 		exit(2);
 	}

 	while ((ch = getopt(argc, argv, "klLcdDxXE:e:M:m:qs:t:")) != -1) {
 		switch (ch) {
 		case 'E':
 			fingerprint_hash = ssh_digest_alg_by_name(optarg);
 			if (fingerprint_hash == -1)
 				fatal("Invalid hash algorithm \"%s\"", optarg);
 			break;
 		case 'k':
 			key_only = 1;
 			break;
 		case 'l':
 		case 'L':
 			if (lflag != 0)
 				fatal("-%c flag already specified", lflag);
 			lflag = ch;
 			break;
 		case 'x':
 		case 'X':
 			if (xflag != 0)
 				fatal("-%c flag already specified", xflag);
 			xflag = ch;
 			break;
 		case 'c':
 			confirm = 1;
 			break;
 		case 'm':
 			minleft = (int)strtonum(optarg, 1, UINT_MAX, NULL);
 			if (minleft == 0) {
 				usage();
 				ret = 1;
 				goto done;
 			}
 			break;
 		case 'M':
 			maxsign = (int)strtonum(optarg, 1, UINT_MAX, NULL);
 			if (maxsign == 0) {
 				usage();
 				ret = 1;
 				goto done;
 			}
 			break;
 		case 'd':
 			deleting = 1;
 			break;
 		case 'D':
 			Dflag = 1;
 			break;
 		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;
 		case 'q':
 			qflag = 1;
 			break;
 		default:
 			usage();
 			ret = 1;
 			goto done;
 		}
 	}

 	if ((xflag != 0) + (lflag != 0) + (Dflag != 0) > 1)
 		fatal("Invalid combination of actions");
 	else if (xflag) {
 		if (lock_agent(agent_fd, xflag == 'x' ? 1 : 0) == -1)
 			ret = 1;
 		goto done;
 	} else if (lflag) {
 		if (list_identities(agent_fd, lflag == 'l' ? 1 : 0) == -1)
 			ret = 1;
 		goto done;
 	} else if (Dflag) {
 		if (delete_all(agent_fd, qflag) == -1)
 			ret = 1;
 		goto done;
 	}

 	argc -= optind;
 	argv += optind;
 	if (pkcs11provider != NULL) {
 		if (update_card(agent_fd, !deleting, pkcs11provider,
 		    qflag) == -1)
 			ret = 1;
 		goto done;
 	}
 	if (argc == 0) {
 		char buf[PATH_MAX];
 		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(agent_fd, deleting, key_only, buf,
 			    qflag) == -1)
 				ret = 1;
 			else
 				count++;
 		}
 		if (count == 0)
 			ret = 1;
 	} else {
 		for (i = 0; i < argc; i++) {
 			if (do_file(agent_fd, deleting, key_only,
 			    argv[i], qflag) == -1)
 				ret = 1;
 		}
 	}
 	clear_pass();

 done:
 	ssh_close_authentication_socket(agent_fd);
 	return ret;
 }
	/* $OpenBSD: ssh-add.c,v 1.136 2018/09/19 02:03:02 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 <openssl/evp.h>
	#include "openbsd-compat/openssl-compat.h"

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

	#include "xmalloc.h"
	#include "ssh.h"
	#include "log.h"
	#include "sshkey.h"
	#include "sshbuf.h"
	#include "authfd.h"
	#include "authfile.h"
	#include "pathnames.h"
	#include "misc.h"
	#include "ssherr.h"
	#include "digest.h"

	/* argv0 */
	extern char *__progname;

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

	static int fingerprint_hash = SSH_FP_HASH_DEFAULT;

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

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

	/* Maximum number of signatures (XMSS) */
	static u_int maxsign = 0;
	static u_int minleft = 0;

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

	static int
	delete_file(int agent_fd, const char *filename, int key_only, int qflag)
	{
	struct sshkey public, cert = NULL;
	char certpath = NULL, comment = NULL;
	int r, ret = -1;

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

	if (key_only)
	goto out;

	/* Now try to delete the corresponding certificate too */
	free(comment);
	comment = NULL;
	xasprintf(&certpath, "%s-cert.pub", filename);
	if ((r = sshkey_load_public(certpath, &cert, &comment)) != 0) {
	if (r != SSH_ERR_SYSTEM_ERROR \|\| errno != ENOENT)
	error("Failed to load certificate \"%s\": %s",
	certpath, ssh_err(r));
	goto out;
	}

	if (!sshkey_equal_public(cert, public))
	fatal("Certificate %s does not match private key %s",
	certpath, filename);

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

	out:
	sshkey_free(cert);
	sshkey_free(public);
	free(certpath);
	free(comment);

	return ret;
	}

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

	/*
	* Since the agent might be forwarded, old or non-OpenSSH, when asked
	* to remove all keys, attempt to remove both protocol v.1 and v.2
	* keys.
	*/
	if (ssh_remove_all_identities(agent_fd, 2) == 0)
	ret = 0;
	/* ignore error-code for ssh1 */
	ssh_remove_all_identities(agent_fd, 1);

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

	return ret;
	}

	static int
	add_file(int agent_fd, const char *filename, int key_only, int qflag)
	{
	struct sshkey private, cert;
	char *comment = NULL;
	char msg[1024], *certpath = NULL;
	int r, fd, ret = -1;
	size_t i;
	u_int32_t left;
	struct sshbuf *keyblob;
	struct ssh_identitylist *idlist;

	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) {
	if (sshkey_perm_ok(fd, filename) != 0) {
	close(fd);
	return -1;
	}
	}
	if ((keyblob = sshbuf_new()) == NULL)
	fatal("%s: sshbuf_new failed", __func__);
	if ((r = sshkey_load_file(fd, keyblob)) != 0) {
	fprintf(stderr, "Error loading key \"%s\": %s\n",
	filename, ssh_err(r));
	sshbuf_free(keyblob);
	close(fd);
	return -1;
	}
	close(fd);

	/* At first, try empty passphrase */
	if ((r = sshkey_parse_private_fileblob(keyblob, "", &private,
	&comment)) != 0 && r != SSH_ERR_KEY_WRONG_PASSPHRASE) {
	fprintf(stderr, "Error loading key \"%s\": %s\n",
	filename, ssh_err(r));
	goto fail_load;
	}
	/* try last */
	if (private == NULL && pass != NULL) {
	if ((r = sshkey_parse_private_fileblob(keyblob, pass, &private,
	&comment)) != 0 && r != SSH_ERR_KEY_WRONG_PASSPHRASE) {
	fprintf(stderr, "Error loading key \"%s\": %s\n",
	filename, ssh_err(r));
	goto fail_load;
	}
	}
	if (private == NULL) {
	/* clear passphrase since it did not work */
	clear_pass();
	snprintf(msg, sizeof msg, "Enter passphrase for %s%s: ",
	filename, confirm ? " (will confirm each use)" : "");
	for (;;) {
	pass = read_passphrase(msg, RP_ALLOW_STDIN);
	if (strcmp(pass, "") == 0)
	goto fail_load;
	if ((r = sshkey_parse_private_fileblob(keyblob, pass,
	&private, &comment)) == 0)
	break;
	else if (r != SSH_ERR_KEY_WRONG_PASSPHRASE) {
	fprintf(stderr,
	"Error loading key \"%s\": %s\n",
	filename, ssh_err(r));
	fail_load:
	clear_pass();
	sshbuf_free(keyblob);
	return -1;
	}
	clear_pass();
	snprintf(msg, sizeof msg,
	"Bad passphrase, try again for %s%s: ", filename,
	confirm ? " (will confirm each use)" : "");
	}
	}
	if (comment == NULL \|\| *comment == '\0')
	comment = xstrdup(filename);
	sshbuf_free(keyblob);

	/* For XMSS */
	if ((r = sshkey_set_filename(private, filename)) != 0) {
	fprintf(stderr, "Could not add filename to private key: %s (%s)\n",
	filename, comment);
	goto out;
	}
	if (maxsign && minleft &&
	(r = ssh_fetch_identitylist(agent_fd, &idlist)) == 0) {
	for (i = 0; i < idlist->nkeys; i++) {
	if (!sshkey_equal_public(idlist->keys[i], private))
	continue;
	left = sshkey_signatures_left(idlist->keys[i]);
	if (left < minleft) {
	fprintf(stderr,
	"Only %d signatures left.\n", left);
	break;
	}
	fprintf(stderr, "Skipping update: ");
	if (left == minleft) {
	fprintf(stderr,
	"required signatures left (%d).\n", left);
	} else {
	fprintf(stderr,
	"more signatures left (%d) than"
	" required (%d).\n", left, minleft);
	}
	ssh_free_identitylist(idlist);
	goto out;
	}
	ssh_free_identitylist(idlist);
	}

	if ((r = ssh_add_identity_constrained(agent_fd, private, comment,
	lifetime, confirm, maxsign)) == 0) {
	ret = 0;
	if (!qflag) {
	fprintf(stderr, "Identity added: %s (%s)\n",
	filename, comment);
	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\": %s\n",
	filename, ssh_err(r));
	}

	/* 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 ((r = sshkey_load_public(certpath, &cert, NULL)) != 0) {
	if (r != SSH_ERR_SYSTEM_ERROR \|\| errno != ENOENT)
	error("Failed to load certificate \"%s\": %s",
	certpath, ssh_err(r));
	goto out;
	}

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

	/* Graft with private bits */
	if ((r = sshkey_to_certified(private)) != 0) {
	error("%s: sshkey_to_certified: %s", __func__, ssh_err(r));
	sshkey_free(cert);
	goto out;
	}
	if ((r = sshkey_cert_copy(cert, private)) != 0) {
	error("%s: sshkey_cert_copy: %s", __func__, ssh_err(r));
	sshkey_free(cert);
	goto out;
	}
	sshkey_free(cert);

	if ((r = ssh_add_identity_constrained(agent_fd, private, comment,
	lifetime, confirm, maxsign)) != 0) {
	error("Certificate %s (%s) add failed: %s", certpath,
	private->cert->key_id, ssh_err(r));
	goto out;
	}
	/* success */
	if (!qflag) {
	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:
	free(certpath);
	free(comment);
	sshkey_free(private);

	return ret;
	}

	static int
	update_card(int agent_fd, int add, const char *id, int qflag)
	{
	char *pin = NULL;
	int r, ret = -1;

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

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

	static int
	list_identities(int agent_fd, int do_fp)
	{
	char *fp;
	int r;
	struct ssh_identitylist *idlist;
	u_int32_t left;
	size_t i;

	if ((r = ssh_fetch_identitylist(agent_fd, &idlist)) != 0) {
	if (r != SSH_ERR_AGENT_NO_IDENTITIES)
	fprintf(stderr, "error fetching identities: %s\n",
	ssh_err(r));
	else
	printf("The agent has no identities.\n");
	return -1;
	}
	for (i = 0; i < idlist->nkeys; i++) {
	if (do_fp) {
	fp = sshkey_fingerprint(idlist->keys[i],
	fingerprint_hash, SSH_FP_DEFAULT);
	printf("%u %s %s (%s)\n", sshkey_size(idlist->keys[i]),
	fp == NULL ? "(null)" : fp, idlist->comments[i],
	sshkey_type(idlist->keys[i]));
	free(fp);
	} else {
	if ((r = sshkey_write(idlist->keys[i], stdout)) != 0) {
	fprintf(stderr, "sshkey_write: %s\n",
	ssh_err(r));
	continue;
	}
	fprintf(stdout, " %s", idlist->comments[i]);
	left = sshkey_signatures_left(idlist->keys[i]);
	if (left > 0)
	fprintf(stdout,
	" [signatures left %d]", left);
	fprintf(stdout, "\n");
	}
	}
	ssh_free_identitylist(idlist);
	return 0;
	}

	static int
	lock_agent(int agent_fd, int lock)
	{
	char prompt[100], p1, p2;
	int r, 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) {
	if ((r = ssh_lock_agent(agent_fd, lock, p1)) == 0) {
	fprintf(stderr, "Agent %slocked.\n", lock ? "" : "un");
	ret = 0;
	} else {
	fprintf(stderr, "Failed to %slock agent: %s\n",
	lock ? "" : "un", ssh_err(r));
	}
	}
	explicit_bzero(p1, strlen(p1));
	free(p1);
	return (ret);
	}

	static int
	do_file(int agent_fd, int deleting, int key_only, char *file, int qflag)
	{
	if (deleting) {
	if (delete_file(agent_fd, file, key_only, qflag) == -1)
	return -1;
	} else {
	if (add_file(agent_fd, file, key_only, qflag) == -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, " -E hash Specify hash algorithm used for fingerprints.\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, " -m minleft Maxsign is only changed if less than minleft are left (for XMSS)\n");
	fprintf(stderr, " -M maxsign Maximum number of signatures allowed (for XMSS)\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");
	fprintf(stderr, " -q Be quiet after a successful operation.\n");
	}

	int
	main(int argc, char **argv)
	{
	extern char *optarg;
	extern int optind;
	int agent_fd;
	char *pkcs11provider = NULL;
	int r, i, ch, deleting = 0, ret = 0, key_only = 0;
	int xflag = 0, lflag = 0, Dflag = 0, qflag = 0;

	ssh_malloc_init(); /* must be called before any mallocs */
	/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
	sanitise_stdfd();

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

	setvbuf(stdout, NULL, _IOLBF, 0);

	/* First, get a connection to the authentication agent. */
	switch (r = ssh_get_authentication_socket(&agent_fd)) {
	case 0:
	break;
	case SSH_ERR_AGENT_NOT_PRESENT:
	fprintf(stderr, "Could not open a connection to your "
	"authentication agent.\n");
	exit(2);
	default:
	fprintf(stderr, "Error connecting to agent: %s\n", ssh_err(r));
	exit(2);
	}

	while ((ch = getopt(argc, argv, "klLcdDxXE:e:M:m:qs:t:")) != -1) {
	switch (ch) {
	case 'E':
	fingerprint_hash = ssh_digest_alg_by_name(optarg);
	if (fingerprint_hash == -1)
	fatal("Invalid hash algorithm \"%s\"", optarg);
	break;
	case 'k':
	key_only = 1;
	break;
	case 'l':
	case 'L':
	if (lflag != 0)
	fatal("-%c flag already specified", lflag);
	lflag = ch;
	break;
	case 'x':
	case 'X':
	if (xflag != 0)
	fatal("-%c flag already specified", xflag);
	xflag = ch;
	break;
	case 'c':
	confirm = 1;
	break;
	case 'm':
	minleft = (int)strtonum(optarg, 1, UINT_MAX, NULL);
	if (minleft == 0) {
	usage();
	ret = 1;
	goto done;
	}
	break;
	case 'M':
	maxsign = (int)strtonum(optarg, 1, UINT_MAX, NULL);
	if (maxsign == 0) {
	usage();
	ret = 1;
	goto done;
	}
	break;
	case 'd':
	deleting = 1;
	break;
	case 'D':
	Dflag = 1;
	break;
	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;
	case 'q':
	qflag = 1;
	break;
	default:
	usage();
	ret = 1;
	goto done;
	}
	}

	if ((xflag != 0) + (lflag != 0) + (Dflag != 0) > 1)
	fatal("Invalid combination of actions");
	else if (xflag) {
	if (lock_agent(agent_fd, xflag == 'x' ? 1 : 0) == -1)
	ret = 1;
	goto done;
	} else if (lflag) {
	if (list_identities(agent_fd, lflag == 'l' ? 1 : 0) == -1)
	ret = 1;
	goto done;
	} else if (Dflag) {
	if (delete_all(agent_fd, qflag) == -1)
	ret = 1;
	goto done;
	}

	argc -= optind;
	argv += optind;
	if (pkcs11provider != NULL) {
	if (update_card(agent_fd, !deleting, pkcs11provider,
	qflag) == -1)
	ret = 1;
	goto done;
	}
	if (argc == 0) {
	char buf[PATH_MAX];
	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(agent_fd, deleting, key_only, buf,
	qflag) == -1)
	ret = 1;
	else
	count++;
	}
	if (count == 0)
	ret = 1;
	} else {
	for (i = 0; i < argc; i++) {
	if (do_file(agent_fd, deleting, key_only,
	argv[i], qflag) == -1)
	ret = 1;
	}
	}
	clear_pass();

	done:
	ssh_close_authentication_socket(agent_fd);
	return ret;
	}