kqueue: Rework timer expiration

[dragonfly.git] / crypto / openssh / ssh-add.c

/* $OpenBSD: ssh-add.c,v 1.113 2014/07/09 14:15:56 benno 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));
        /* 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 (comment == NULL)
                comment = xstrdup(filename);
        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();

        setlinebuf(stdout);

        /* 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;
}