blob: 07558ae52d95cf4972e84d2c54000ab9c63997cd [file] [log] [blame] [raw]
/* $OpenBSD: ssh-add.c,v 1.111 2014/06/27 18:50:39 markus 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"
#include "ssherr.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 r, 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 */
if ((r = sshkey_parse_private_fileblob(&keyblob, "", filename,
&private, &comment)) != 0 && r != SSH_ERR_KEY_WRONG_PASSPHRASE)
fatal("Cannot parse %s: %s", filename, ssh_err(r));
if (comment == NULL)
comment = xstrdup(filename);
/* try last */
if (private == NULL && pass != NULL) {
if ((r = sshkey_parse_private_fileblob(&keyblob, pass, filename,
&private, &comment)) != 0 &&
r != SSH_ERR_KEY_WRONG_PASSPHRASE)
fatal("Cannot parse %s: %s", filename, ssh_err(r));
}
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;
}
if ((r = sshkey_parse_private_fileblob(&keyblob,
pass, filename, &private, NULL)) != 0 &&
r != SSH_ERR_KEY_WRONG_PASSPHRASE)
fatal("Cannot parse %s: %s",
filename, ssh_err(r));
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;
}