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-rw-r--r--ssh-add.c699
1 files changed, 699 insertions, 0 deletions
diff --git a/ssh-add.c b/ssh-add.c
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index 0000000..627c029
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+++ b/ssh-add.c
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+/* $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();
+
+#ifdef WITH_OPENSSL
+ OpenSSL_add_all_algorithms();
+#endif
+
+ 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;
+}