mirror of
https://github.com/freebsd/freebsd-src
synced 2024-09-06 17:18:32 +00:00
![Ed Maste](/assets/img/avatar_default.png)
Some notable changes, from upstream's release notes: - sshd(8): Remove support for obsolete "host/port" syntax. - ssh(1): When prompting whether to record a new host key, accept the key fingerprint as a synonym for "yes". - ssh-keygen(1): when acting as a CA and signing certificates with an RSA key, default to using the rsa-sha2-512 signature algorithm. - ssh(1), sshd(8), ssh-keygen(1): this release removes the "ssh-rsa" (RSA/SHA1) algorithm from those accepted for certificate signatures. - ssh-sk-helper(8): this is a new binary. It is used by the FIDO/U2F support to provide address-space isolation for token middleware libraries (including the internal one). - ssh(1): this release enables UpdateHostkeys by default subject to some conservative preconditions. - scp(1): this release changes the behaviour of remote to remote copies (e.g. "scp host-a:/path host-b:") to transfer through the local host by default. - scp(1): experimental support for transfers using the SFTP protocol as a replacement for the venerable SCP/RCP protocol that it has traditionally used. Additional integration work is needed to support FIDO/U2F in the base system. Deprecation Notice ------------------ OpenSSH will disable the ssh-rsa signature scheme by default in the next release. Reviewed by: imp MFC after: 1 month Relnotes: Yes Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D29985
274 lines
6.9 KiB
C
274 lines
6.9 KiB
C
/* $OpenBSD: auth-krb5.c,v 1.24 2021/04/03 06:18:40 djm Exp $ */
|
|
/*
|
|
* Kerberos v5 authentication and ticket-passing routines.
|
|
*
|
|
* From: FreeBSD: src/crypto/openssh/auth-krb5.c,v 1.6 2001/02/13 16:58:04 assar
|
|
*/
|
|
/*
|
|
* Copyright (c) 2002 Daniel Kouril. 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 <pwd.h>
|
|
#include <stdarg.h>
|
|
|
|
#include "xmalloc.h"
|
|
#include "ssh.h"
|
|
#include "packet.h"
|
|
#include "log.h"
|
|
#include "sshbuf.h"
|
|
#include "sshkey.h"
|
|
#include "misc.h"
|
|
#include "servconf.h"
|
|
#include "uidswap.h"
|
|
#include "hostfile.h"
|
|
#include "auth.h"
|
|
|
|
#ifdef KRB5
|
|
#include <errno.h>
|
|
#include <unistd.h>
|
|
#include <string.h>
|
|
#include <krb5.h>
|
|
|
|
extern ServerOptions options;
|
|
|
|
static int
|
|
krb5_init(void *context)
|
|
{
|
|
Authctxt *authctxt = (Authctxt *)context;
|
|
krb5_error_code problem;
|
|
|
|
if (authctxt->krb5_ctx == NULL) {
|
|
problem = krb5_init_context(&authctxt->krb5_ctx);
|
|
if (problem)
|
|
return (problem);
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
int
|
|
auth_krb5_password(Authctxt *authctxt, const char *password)
|
|
{
|
|
#ifndef HEIMDAL
|
|
krb5_creds creds;
|
|
krb5_principal server;
|
|
#endif
|
|
krb5_error_code problem;
|
|
krb5_ccache ccache = NULL;
|
|
int len;
|
|
char *client, *platform_client;
|
|
const char *errmsg;
|
|
|
|
/* get platform-specific kerberos client principal name (if it exists) */
|
|
platform_client = platform_krb5_get_principal_name(authctxt->pw->pw_name);
|
|
client = platform_client ? platform_client : authctxt->pw->pw_name;
|
|
|
|
temporarily_use_uid(authctxt->pw);
|
|
|
|
problem = krb5_init(authctxt);
|
|
if (problem)
|
|
goto out;
|
|
|
|
problem = krb5_parse_name(authctxt->krb5_ctx, client,
|
|
&authctxt->krb5_user);
|
|
if (problem)
|
|
goto out;
|
|
|
|
#ifdef HEIMDAL
|
|
# ifdef HAVE_KRB5_CC_NEW_UNIQUE
|
|
problem = krb5_cc_new_unique(authctxt->krb5_ctx,
|
|
krb5_mcc_ops.prefix, NULL, &ccache);
|
|
# else
|
|
problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_mcc_ops, &ccache);
|
|
# endif
|
|
if (problem)
|
|
goto out;
|
|
|
|
problem = krb5_cc_initialize(authctxt->krb5_ctx, ccache,
|
|
authctxt->krb5_user);
|
|
if (problem)
|
|
goto out;
|
|
|
|
restore_uid();
|
|
|
|
problem = krb5_verify_user(authctxt->krb5_ctx, authctxt->krb5_user,
|
|
ccache, password, 1, NULL);
|
|
|
|
temporarily_use_uid(authctxt->pw);
|
|
|
|
if (problem)
|
|
goto out;
|
|
|
|
# ifdef HAVE_KRB5_CC_NEW_UNIQUE
|
|
problem = krb5_cc_new_unique(authctxt->krb5_ctx,
|
|
krb5_fcc_ops.prefix, NULL, &authctxt->krb5_fwd_ccache);
|
|
# else
|
|
problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_fcc_ops,
|
|
&authctxt->krb5_fwd_ccache);
|
|
# endif
|
|
if (problem)
|
|
goto out;
|
|
|
|
problem = krb5_cc_copy_cache(authctxt->krb5_ctx, ccache,
|
|
authctxt->krb5_fwd_ccache);
|
|
krb5_cc_destroy(authctxt->krb5_ctx, ccache);
|
|
ccache = NULL;
|
|
if (problem)
|
|
goto out;
|
|
|
|
#else
|
|
problem = krb5_get_init_creds_password(authctxt->krb5_ctx, &creds,
|
|
authctxt->krb5_user, (char *)password, NULL, NULL, 0, NULL, NULL);
|
|
if (problem)
|
|
goto out;
|
|
|
|
problem = krb5_sname_to_principal(authctxt->krb5_ctx, NULL, NULL,
|
|
KRB5_NT_SRV_HST, &server);
|
|
if (problem)
|
|
goto out;
|
|
|
|
restore_uid();
|
|
problem = krb5_verify_init_creds(authctxt->krb5_ctx, &creds, server,
|
|
NULL, NULL, NULL);
|
|
krb5_free_principal(authctxt->krb5_ctx, server);
|
|
temporarily_use_uid(authctxt->pw);
|
|
if (problem)
|
|
goto out;
|
|
|
|
if (!krb5_kuserok(authctxt->krb5_ctx, authctxt->krb5_user,
|
|
authctxt->pw->pw_name)) {
|
|
problem = -1;
|
|
goto out;
|
|
}
|
|
|
|
problem = ssh_krb5_cc_gen(authctxt->krb5_ctx,
|
|
&authctxt->krb5_fwd_ccache);
|
|
if (problem)
|
|
goto out;
|
|
|
|
problem = krb5_cc_initialize(authctxt->krb5_ctx,
|
|
authctxt->krb5_fwd_ccache, authctxt->krb5_user);
|
|
if (problem)
|
|
goto out;
|
|
|
|
problem = krb5_cc_store_cred(authctxt->krb5_ctx,
|
|
authctxt->krb5_fwd_ccache, &creds);
|
|
if (problem)
|
|
goto out;
|
|
#endif
|
|
|
|
authctxt->krb5_ticket_file = (char *)krb5_cc_get_name(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache);
|
|
|
|
len = strlen(authctxt->krb5_ticket_file) + 6;
|
|
authctxt->krb5_ccname = xmalloc(len);
|
|
snprintf(authctxt->krb5_ccname, len, "FILE:%s",
|
|
authctxt->krb5_ticket_file);
|
|
|
|
#ifdef USE_PAM
|
|
if (options.use_pam)
|
|
do_pam_putenv("KRB5CCNAME", authctxt->krb5_ccname);
|
|
#endif
|
|
|
|
out:
|
|
restore_uid();
|
|
|
|
free(platform_client);
|
|
|
|
if (problem) {
|
|
if (ccache)
|
|
krb5_cc_destroy(authctxt->krb5_ctx, ccache);
|
|
|
|
if (authctxt->krb5_ctx != NULL && problem!=-1) {
|
|
errmsg = krb5_get_error_message(authctxt->krb5_ctx,
|
|
problem);
|
|
debug("Kerberos password authentication failed: %s",
|
|
errmsg);
|
|
krb5_free_error_message(authctxt->krb5_ctx, errmsg);
|
|
} else
|
|
debug("Kerberos password authentication failed: %d",
|
|
problem);
|
|
|
|
krb5_cleanup_proc(authctxt);
|
|
|
|
if (options.kerberos_or_local_passwd)
|
|
return (-1);
|
|
else
|
|
return (0);
|
|
}
|
|
return (authctxt->valid ? 1 : 0);
|
|
}
|
|
|
|
void
|
|
krb5_cleanup_proc(Authctxt *authctxt)
|
|
{
|
|
debug("krb5_cleanup_proc called");
|
|
if (authctxt->krb5_fwd_ccache) {
|
|
krb5_cc_destroy(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache);
|
|
authctxt->krb5_fwd_ccache = NULL;
|
|
}
|
|
if (authctxt->krb5_user) {
|
|
krb5_free_principal(authctxt->krb5_ctx, authctxt->krb5_user);
|
|
authctxt->krb5_user = NULL;
|
|
}
|
|
if (authctxt->krb5_ctx) {
|
|
krb5_free_context(authctxt->krb5_ctx);
|
|
authctxt->krb5_ctx = NULL;
|
|
}
|
|
}
|
|
|
|
#ifndef HEIMDAL
|
|
krb5_error_code
|
|
ssh_krb5_cc_gen(krb5_context ctx, krb5_ccache *ccache) {
|
|
int tmpfd, ret, oerrno;
|
|
char ccname[40];
|
|
mode_t old_umask;
|
|
|
|
ret = snprintf(ccname, sizeof(ccname),
|
|
"FILE:/tmp/krb5cc_%d_XXXXXXXXXX", geteuid());
|
|
if (ret < 0 || (size_t)ret >= sizeof(ccname))
|
|
return ENOMEM;
|
|
|
|
old_umask = umask(0177);
|
|
tmpfd = mkstemp(ccname + strlen("FILE:"));
|
|
oerrno = errno;
|
|
umask(old_umask);
|
|
if (tmpfd == -1) {
|
|
logit("mkstemp(): %.100s", strerror(oerrno));
|
|
return oerrno;
|
|
}
|
|
|
|
if (fchmod(tmpfd,S_IRUSR | S_IWUSR) == -1) {
|
|
oerrno = errno;
|
|
logit("fchmod(): %.100s", strerror(oerrno));
|
|
close(tmpfd);
|
|
return oerrno;
|
|
}
|
|
close(tmpfd);
|
|
|
|
return (krb5_cc_resolve(ctx, ccname, ccache));
|
|
}
|
|
#endif /* !HEIMDAL */
|
|
#endif /* KRB5 */
|