611 lines
16 KiB
C
611 lines
16 KiB
C
/* $OpenBSD: ssh-add.c,v 1.131 2017/05/05 10:42:49 naddy Exp $ */
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/*
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* Author: Tatu Ylonen <ylo@cs.hut.fi>
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* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
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* All rights reserved
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* Adds an identity to the authentication server, or removes an identity.
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*
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* As far as I am concerned, the code I have written for this software
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* can be used freely for any purpose. Any derived versions of this
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* software must be clearly marked as such, and if the derived work is
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* incompatible with the protocol description in the RFC file, it must be
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* called by a name other than "ssh" or "Secure Shell".
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*
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* SSH2 implementation,
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* Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "includes.h"
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <openssl/evp.h>
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#include "openbsd-compat/openssl-compat.h"
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#include <errno.h>
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#include <fcntl.h>
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#include <pwd.h>
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#include <stdarg.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include <limits.h>
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#include "xmalloc.h"
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#include "ssh.h"
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#include "rsa.h"
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#include "log.h"
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#include "sshkey.h"
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#include "sshbuf.h"
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#include "authfd.h"
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#include "authfile.h"
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#include "pathnames.h"
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#include "misc.h"
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#include "ssherr.h"
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#include "digest.h"
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/* argv0 */
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extern char *__progname;
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/* Default files to add */
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static char *default_files[] = {
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#ifdef WITH_OPENSSL
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_PATH_SSH_CLIENT_ID_RSA,
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_PATH_SSH_CLIENT_ID_DSA,
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#ifdef OPENSSL_HAS_ECC
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_PATH_SSH_CLIENT_ID_ECDSA,
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#endif
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#endif /* WITH_OPENSSL */
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_PATH_SSH_CLIENT_ID_ED25519,
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NULL
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};
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static int fingerprint_hash = SSH_FP_HASH_DEFAULT;
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/* Default lifetime (0 == forever) */
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static int lifetime = 0;
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/* User has to confirm key use */
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static int confirm = 0;
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/* we keep a cache of one passphrase */
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static char *pass = NULL;
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static void
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clear_pass(void)
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{
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if (pass) {
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explicit_bzero(pass, strlen(pass));
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free(pass);
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pass = NULL;
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}
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}
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static int
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delete_file(int agent_fd, const char *filename, int key_only)
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{
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struct sshkey *public, *cert = NULL;
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char *certpath = NULL, *comment = NULL;
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int r, ret = -1;
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if ((r = sshkey_load_public(filename, &public, &comment)) != 0) {
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printf("Bad key file %s: %s\n", filename, ssh_err(r));
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return -1;
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}
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if ((r = ssh_remove_identity(agent_fd, public)) == 0) {
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fprintf(stderr, "Identity removed: %s (%s)\n", filename, comment);
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ret = 0;
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} else
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fprintf(stderr, "Could not remove identity \"%s\": %s\n",
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filename, ssh_err(r));
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if (key_only)
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goto out;
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/* Now try to delete the corresponding certificate too */
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free(comment);
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comment = NULL;
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xasprintf(&certpath, "%s-cert.pub", filename);
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if ((r = sshkey_load_public(certpath, &cert, &comment)) != 0) {
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if (r != SSH_ERR_SYSTEM_ERROR || errno != ENOENT)
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error("Failed to load certificate \"%s\": %s",
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certpath, ssh_err(r));
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goto out;
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}
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if (!sshkey_equal_public(cert, public))
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fatal("Certificate %s does not match private key %s",
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certpath, filename);
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if ((r = ssh_remove_identity(agent_fd, cert)) == 0) {
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fprintf(stderr, "Identity removed: %s (%s)\n", certpath,
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comment);
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ret = 0;
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} else
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fprintf(stderr, "Could not remove identity \"%s\": %s\n",
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certpath, ssh_err(r));
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out:
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sshkey_free(cert);
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sshkey_free(public);
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free(certpath);
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free(comment);
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return ret;
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}
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/* Send a request to remove all identities. */
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static int
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delete_all(int agent_fd)
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{
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int ret = -1;
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/*
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* Since the agent might be forwarded, old or non-OpenSSH, when asked
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* to remove all keys, attempt to remove both protocol v.1 and v.2
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* keys.
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*/
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if (ssh_remove_all_identities(agent_fd, 2) == 0)
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ret = 0;
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/* ignore error-code for ssh1 */
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ssh_remove_all_identities(agent_fd, 1);
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if (ret == 0)
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fprintf(stderr, "All identities removed.\n");
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else
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fprintf(stderr, "Failed to remove all identities.\n");
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return ret;
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}
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static int
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add_file(int agent_fd, const char *filename, int key_only)
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{
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struct sshkey *private, *cert;
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char *comment = NULL;
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char msg[1024], *certpath = NULL;
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int r, fd, ret = -1;
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struct sshbuf *keyblob;
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if (strcmp(filename, "-") == 0) {
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fd = STDIN_FILENO;
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filename = "(stdin)";
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} else if ((fd = open(filename, O_RDONLY)) < 0) {
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perror(filename);
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return -1;
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}
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/*
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* Since we'll try to load a keyfile multiple times, permission errors
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* will occur multiple times, so check perms first and bail if wrong.
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*/
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if (fd != STDIN_FILENO) {
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if (sshkey_perm_ok(fd, filename) != 0) {
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close(fd);
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return -1;
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}
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}
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if ((keyblob = sshbuf_new()) == NULL)
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fatal("%s: sshbuf_new failed", __func__);
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if ((r = sshkey_load_file(fd, keyblob)) != 0) {
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fprintf(stderr, "Error loading key \"%s\": %s\n",
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filename, ssh_err(r));
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sshbuf_free(keyblob);
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close(fd);
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return -1;
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}
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close(fd);
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/* At first, try empty passphrase */
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if ((r = sshkey_parse_private_fileblob(keyblob, "", &private,
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&comment)) != 0 && r != SSH_ERR_KEY_WRONG_PASSPHRASE) {
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fprintf(stderr, "Error loading key \"%s\": %s\n",
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filename, ssh_err(r));
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goto fail_load;
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}
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/* try last */
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if (private == NULL && pass != NULL) {
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if ((r = sshkey_parse_private_fileblob(keyblob, pass, &private,
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&comment)) != 0 && r != SSH_ERR_KEY_WRONG_PASSPHRASE) {
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fprintf(stderr, "Error loading key \"%s\": %s\n",
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filename, ssh_err(r));
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goto fail_load;
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}
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}
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if (private == NULL) {
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/* clear passphrase since it did not work */
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clear_pass();
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snprintf(msg, sizeof msg, "Enter passphrase for %s%s: ",
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filename, confirm ? " (will confirm each use)" : "");
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for (;;) {
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pass = read_passphrase(msg, RP_ALLOW_STDIN);
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if (strcmp(pass, "") == 0)
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goto fail_load;
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if ((r = sshkey_parse_private_fileblob(keyblob, pass,
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&private, &comment)) == 0)
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break;
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else if (r != SSH_ERR_KEY_WRONG_PASSPHRASE) {
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fprintf(stderr,
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"Error loading key \"%s\": %s\n",
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filename, ssh_err(r));
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fail_load:
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clear_pass();
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sshbuf_free(keyblob);
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return -1;
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}
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clear_pass();
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snprintf(msg, sizeof msg,
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"Bad passphrase, try again for %s%s: ", filename,
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confirm ? " (will confirm each use)" : "");
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}
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}
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if (comment == NULL || *comment == '\0')
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comment = xstrdup(filename);
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sshbuf_free(keyblob);
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if ((r = ssh_add_identity_constrained(agent_fd, private, comment,
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lifetime, confirm)) == 0) {
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fprintf(stderr, "Identity added: %s (%s)\n", filename, comment);
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ret = 0;
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if (lifetime != 0)
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fprintf(stderr,
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"Lifetime set to %d seconds\n", lifetime);
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if (confirm != 0)
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fprintf(stderr,
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"The user must confirm each use of the key\n");
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} else {
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fprintf(stderr, "Could not add identity \"%s\": %s\n",
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filename, ssh_err(r));
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}
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/* Skip trying to load the cert if requested */
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if (key_only)
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goto out;
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/* Now try to add the certificate flavour too */
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xasprintf(&certpath, "%s-cert.pub", filename);
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if ((r = sshkey_load_public(certpath, &cert, NULL)) != 0) {
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if (r != SSH_ERR_SYSTEM_ERROR || errno != ENOENT)
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error("Failed to load certificate \"%s\": %s",
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certpath, ssh_err(r));
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goto out;
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}
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if (!sshkey_equal_public(cert, private)) {
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error("Certificate %s does not match private key %s",
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certpath, filename);
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sshkey_free(cert);
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goto out;
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}
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/* Graft with private bits */
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if ((r = sshkey_to_certified(private)) != 0) {
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error("%s: sshkey_to_certified: %s", __func__, ssh_err(r));
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sshkey_free(cert);
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goto out;
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}
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if ((r = sshkey_cert_copy(cert, private)) != 0) {
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error("%s: key_cert_copy: %s", __func__, ssh_err(r));
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sshkey_free(cert);
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goto out;
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}
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sshkey_free(cert);
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if ((r = ssh_add_identity_constrained(agent_fd, private, comment,
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lifetime, confirm)) != 0) {
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error("Certificate %s (%s) add failed: %s", certpath,
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private->cert->key_id, ssh_err(r));
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goto out;
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}
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fprintf(stderr, "Certificate added: %s (%s)\n", certpath,
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private->cert->key_id);
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if (lifetime != 0)
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fprintf(stderr, "Lifetime set to %d seconds\n", lifetime);
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if (confirm != 0)
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fprintf(stderr, "The user must confirm each use of the key\n");
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out:
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free(certpath);
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free(comment);
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sshkey_free(private);
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return ret;
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}
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static int
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update_card(int agent_fd, int add, const char *id)
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{
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char *pin = NULL;
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int r, ret = -1;
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if (add) {
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if ((pin = read_passphrase("Enter passphrase for PKCS#11: ",
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RP_ALLOW_STDIN)) == NULL)
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return -1;
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}
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if ((r = ssh_update_card(agent_fd, add, id, pin == NULL ? "" : pin,
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lifetime, confirm)) == 0) {
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fprintf(stderr, "Card %s: %s\n",
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add ? "added" : "removed", id);
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ret = 0;
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} else {
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fprintf(stderr, "Could not %s card \"%s\": %s\n",
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add ? "add" : "remove", id, ssh_err(r));
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ret = -1;
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}
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free(pin);
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return ret;
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}
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static int
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list_identities(int agent_fd, int do_fp)
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{
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char *fp;
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int r;
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struct ssh_identitylist *idlist;
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size_t i;
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if ((r = ssh_fetch_identitylist(agent_fd, &idlist)) != 0) {
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if (r != SSH_ERR_AGENT_NO_IDENTITIES)
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fprintf(stderr, "error fetching identities: %s\n",
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ssh_err(r));
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else
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printf("The agent has no identities.\n");
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return -1;
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}
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for (i = 0; i < idlist->nkeys; i++) {
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if (do_fp) {
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fp = sshkey_fingerprint(idlist->keys[i],
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fingerprint_hash, SSH_FP_DEFAULT);
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printf("%u %s %s (%s)\n", sshkey_size(idlist->keys[i]),
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fp == NULL ? "(null)" : fp, idlist->comments[i],
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sshkey_type(idlist->keys[i]));
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free(fp);
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} else {
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if ((r = sshkey_write(idlist->keys[i], stdout)) != 0) {
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fprintf(stderr, "sshkey_write: %s\n",
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ssh_err(r));
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continue;
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}
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fprintf(stdout, " %s\n", idlist->comments[i]);
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}
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}
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ssh_free_identitylist(idlist);
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return 0;
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}
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static int
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lock_agent(int agent_fd, int lock)
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{
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char prompt[100], *p1, *p2;
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int r, passok = 1, ret = -1;
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strlcpy(prompt, "Enter lock password: ", sizeof(prompt));
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p1 = read_passphrase(prompt, RP_ALLOW_STDIN);
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if (lock) {
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strlcpy(prompt, "Again: ", sizeof prompt);
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p2 = read_passphrase(prompt, RP_ALLOW_STDIN);
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if (strcmp(p1, p2) != 0) {
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fprintf(stderr, "Passwords do not match.\n");
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passok = 0;
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}
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explicit_bzero(p2, strlen(p2));
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free(p2);
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}
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if (passok) {
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if ((r = ssh_lock_agent(agent_fd, lock, p1)) == 0) {
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fprintf(stderr, "Agent %slocked.\n", lock ? "" : "un");
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ret = 0;
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} else {
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fprintf(stderr, "Failed to %slock agent: %s\n",
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lock ? "" : "un", ssh_err(r));
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}
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}
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explicit_bzero(p1, strlen(p1));
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free(p1);
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return (ret);
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}
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static int
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do_file(int agent_fd, int deleting, int key_only, char *file)
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{
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if (deleting) {
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if (delete_file(agent_fd, file, key_only) == -1)
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return -1;
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} else {
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if (add_file(agent_fd, file, key_only) == -1)
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return -1;
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}
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return 0;
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}
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static void
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usage(void)
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{
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fprintf(stderr, "usage: %s [options] [file ...]\n", __progname);
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fprintf(stderr, "Options:\n");
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fprintf(stderr, " -l List fingerprints of all identities.\n");
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fprintf(stderr, " -E hash Specify hash algorithm used for fingerprints.\n");
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fprintf(stderr, " -L List public key parameters of all identities.\n");
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fprintf(stderr, " -k Load only keys and not certificates.\n");
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fprintf(stderr, " -c Require confirmation to sign using identities\n");
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fprintf(stderr, " -t life Set lifetime (in seconds) when adding identities.\n");
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fprintf(stderr, " -d Delete identity.\n");
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fprintf(stderr, " -D Delete all identities.\n");
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fprintf(stderr, " -x Lock agent.\n");
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fprintf(stderr, " -X Unlock agent.\n");
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fprintf(stderr, " -s pkcs11 Add keys from PKCS#11 provider.\n");
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fprintf(stderr, " -e pkcs11 Remove keys provided by PKCS#11 provider.\n");
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}
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int
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main(int argc, char **argv)
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{
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extern char *optarg;
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extern int optind;
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int agent_fd;
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char *pkcs11provider = NULL;
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int r, i, ch, deleting = 0, ret = 0, key_only = 0;
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int xflag = 0, lflag = 0, Dflag = 0;
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ssh_malloc_init(); /* must be called before any mallocs */
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/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
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sanitise_stdfd();
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__progname = ssh_get_progname(argv[0]);
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seed_rng();
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#ifdef WITH_OPENSSL
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OpenSSL_add_all_algorithms();
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#endif
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setvbuf(stdout, NULL, _IOLBF, 0);
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/* First, get a connection to the authentication agent. */
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switch (r = ssh_get_authentication_socket(&agent_fd)) {
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case 0:
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break;
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case SSH_ERR_AGENT_NOT_PRESENT:
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fprintf(stderr, "Could not open a connection to your "
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"authentication agent.\n");
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exit(2);
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default:
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fprintf(stderr, "Error connecting to agent: %s\n", ssh_err(r));
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exit(2);
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}
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while ((ch = getopt(argc, argv, "klLcdDxXE:e:s:t:")) != -1) {
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switch (ch) {
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case 'E':
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fingerprint_hash = ssh_digest_alg_by_name(optarg);
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if (fingerprint_hash == -1)
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fatal("Invalid hash algorithm \"%s\"", optarg);
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break;
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case 'k':
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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 '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;
|
|
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) == -1)
|
|
ret = 1;
|
|
goto done;
|
|
}
|
|
|
|
argc -= optind;
|
|
argv += optind;
|
|
if (pkcs11provider != NULL) {
|
|
if (update_card(agent_fd, !deleting, pkcs11provider) == -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) == -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]) == -1)
|
|
ret = 1;
|
|
}
|
|
}
|
|
clear_pass();
|
|
|
|
done:
|
|
ssh_close_authentication_socket(agent_fd);
|
|
return ret;
|
|
}
|