/* $OpenBSD: auth2-pubkey.c,v 1.93 2019/09/03 08:30:47 djm Exp $ */
/*
* Copyright (c) 2000 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 <errno.h>
#include <fcntl.h>
#ifdef HAVE_PATHS_H
# include <paths.h>
#endif
#include <pwd.h>
#include <signal.h>
#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <limits.h>
#include "xmalloc.h"
#include "ssh.h"
#include "ssh2.h"
#include "packet.h"
#include "sshbuf.h"
#include "log.h"
#include "misc.h"
#include "servconf.h"
#include "compat.h"
#include "sshkey.h"
#include "hostfile.h"
#include "auth.h"
#include "pathnames.h"
#include "uidswap.h"
#include "auth-options.h"
#include "canohost.h"
#ifdef GSSAPI
#include "ssh-gss.h"
#endif
#include "monitor_wrap.h"
#include "authfile.h"
#include "match.h"
#include "ssherr.h"
#include "channels.h" /* XXX for session.h */
#include "session.h" /* XXX for child_set_env(); refactor? */
/* import */
extern ServerOptions options;
extern u_char *session_id2;
extern u_int session_id2_len;
static char *
format_key(const struct sshkey *key)
{
char *ret, *fp = sshkey_fingerprint(key,
options.fingerprint_hash, SSH_FP_DEFAULT);
xasprintf(&ret, "%s %s", sshkey_type(key), fp);
free(fp);
return ret;
}
static int
userauth_pubkey(struct ssh *ssh)
{
Authctxt *authctxt = ssh->authctxt;
struct passwd *pw = authctxt->pw;
struct sshbuf *b = NULL;
struct sshkey *key = NULL;
char *pkalg = NULL, *userstyle = NULL, *key_s = NULL, *ca_s = NULL;
u_char *pkblob = NULL, *sig = NULL, have_sig;
size_t blen, slen;
int r, pktype;
int authenticated = 0;
struct sshauthopt *authopts = NULL;
if ((r = sshpkt_get_u8(ssh, &have_sig)) != 0 ||
(r = sshpkt_get_cstring(ssh, &pkalg, NULL)) != 0 ||
(r = sshpkt_get_string(ssh, &pkblob, &blen)) != 0)
fatal("%s: parse request failed: %s", __func__, ssh_err(r));
if (log_level_get() >= SYSLOG_LEVEL_DEBUG2) {
char *keystring;
struct sshbuf *pkbuf;
if ((pkbuf = sshbuf_from(pkblob, blen)) == NULL)
fatal("%s: sshbuf_from failed", __func__);
if ((keystring = sshbuf_dtob64_string(pkbuf, 0)) == NULL)
fatal("%s: sshbuf_dtob64 failed", __func__);
debug2("%s: %s user %s %s public key %s %s", __func__,
authctxt->valid ? "valid" : "invalid", authctxt->user,
have_sig ? "attempting" : "querying", pkalg, keystring);
sshbuf_free(pkbuf);
free(keystring);
}
pktype = sshkey_type_from_name(pkalg);
if (pktype == KEY_UNSPEC) {
/* this is perfectly legal */
verbose("%s: unsupported public key algorithm: %s",
__func__, pkalg);
goto done;
}