NetBSD/crypto/dist/ssh/auth-krb5.c

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/* $NetBSD: auth-krb5.c,v 1.11 2002/10/01 14:07:26 itojun Exp $ */
/*
* Kerberos v5 authentication and ticket-passing routines.
*
* $FreeBSD: src/crypto/openssh/auth-krb5.c,v 1.6 2001/02/13 16:58:04 assar Exp $
*/
/*
* 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"
RCSID("$OpenBSD: auth-krb5.c,v 1.9 2002/09/09 06:48:06 itojun Exp $");
#include "ssh.h"
#include "ssh1.h"
#include "packet.h"
#include "xmalloc.h"
#include "log.h"
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#include "servconf.h"
#include "uidswap.h"
#include "auth.h"
#ifdef KRB5
#include <krb5.h>
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extern ServerOptions options;
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static int
krb5_init(void *context)
{
Authctxt *authctxt = (Authctxt *)context;
krb5_error_code problem;
static int cleanup_registered = 0;
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if (authctxt->krb5_ctx == NULL) {
problem = krb5_init_context(&authctxt->krb5_ctx);
if (problem)
return (problem);
krb5_init_ets(authctxt->krb5_ctx);
}
if (!cleanup_registered) {
fatal_add_cleanup(krb5_cleanup_proc, authctxt);
cleanup_registered = 1;
}
return (0);
}
/*
* Try krb5 authentication. server_user is passed for logging purposes
* only, in auth is received ticket, in client is returned principal
* from the ticket
*/
int
auth_krb5(Authctxt *authctxt, krb5_data *auth, char **client, krb5_data *reply)
{
krb5_error_code problem;
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krb5_principal server;
krb5_ticket *ticket;
int fd, ret;
ret = 0;
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server = NULL;
ticket = NULL;
reply->length = 0;
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problem = krb5_init(authctxt);
if (problem)
goto err;
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problem = krb5_auth_con_init(authctxt->krb5_ctx,
&authctxt->krb5_auth_ctx);
if (problem)
goto err;
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fd = packet_get_connection_in();
problem = krb5_auth_con_setaddrs_from_fd(authctxt->krb5_ctx,
authctxt->krb5_auth_ctx, &fd);
if (problem)
goto err;
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problem = krb5_sname_to_principal(authctxt->krb5_ctx, NULL, NULL ,
KRB5_NT_SRV_HST, &server);
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if (problem)
goto err;
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problem = krb5_rd_req(authctxt->krb5_ctx, &authctxt->krb5_auth_ctx,
auth, server, NULL, NULL, &ticket);
if (problem)
goto err;
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problem = krb5_copy_principal(authctxt->krb5_ctx, ticket->client,
&authctxt->krb5_user);
if (problem)
goto err;
/* if client wants mutual auth */
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problem = krb5_mk_rep(authctxt->krb5_ctx, authctxt->krb5_auth_ctx,
reply);
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if (problem)
goto err;
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/* Check .k5login authorization now. */
if (!krb5_kuserok(authctxt->krb5_ctx, authctxt->krb5_user,
authctxt->pw->pw_name))
goto err;
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if (client)
krb5_unparse_name(authctxt->krb5_ctx, authctxt->krb5_user,
client);
ret = 1;
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err:
if (server)
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krb5_free_principal(authctxt->krb5_ctx, server);
if (ticket)
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krb5_free_ticket(authctxt->krb5_ctx, ticket);
if (!ret && reply->length) {
xfree(reply->data);
memset(reply, 0, sizeof(*reply));
}
if (problem) {
if (authctxt->krb5_ctx != NULL)
debug("Kerberos v5 authentication failed: %s",
krb5_get_err_text(authctxt->krb5_ctx, problem));
else
debug("Kerberos v5 authentication failed: %d",
problem);
}
return (ret);
}
int
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auth_krb5_tgt(Authctxt *authctxt, krb5_data *tgt)
{
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krb5_error_code problem;
krb5_ccache ccache = NULL;
char *pname;
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if (authctxt->pw == NULL || authctxt->krb5_user == NULL)
return (0);
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temporarily_use_uid(authctxt->pw);
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problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_fcc_ops, &ccache);
if (problem)
goto fail;
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problem = krb5_cc_initialize(authctxt->krb5_ctx, ccache,
authctxt->krb5_user);
if (problem)
goto fail;
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problem = krb5_rd_cred2(authctxt->krb5_ctx, authctxt->krb5_auth_ctx,
ccache, tgt);
if (problem)
goto fail;
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authctxt->krb5_fwd_ccache = ccache;
ccache = NULL;
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authctxt->krb5_ticket_file = (char *)krb5_cc_get_name(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache);
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problem = krb5_unparse_name(authctxt->krb5_ctx, authctxt->krb5_user,
&pname);
if (problem)
goto fail;
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debug("Kerberos v5 TGT accepted (%s)", pname);
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restore_uid();
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return (1);
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fail:
if (problem)
debug("Kerberos v5 TGT passing failed: %s",
krb5_get_err_text(authctxt->krb5_ctx, problem));
if (ccache)
krb5_cc_destroy(authctxt->krb5_ctx, ccache);
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restore_uid();
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return (0);
}
int
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auth_krb5_password(Authctxt *authctxt, const char *password)
{
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krb5_error_code problem;
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if (authctxt->pw == NULL)
return (0);
temporarily_use_uid(authctxt->pw);
problem = krb5_init(authctxt);
if (problem)
goto out;
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problem = krb5_parse_name(authctxt->krb5_ctx, authctxt->pw->pw_name,
&authctxt->krb5_user);
if (problem)
goto out;
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problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_mcc_ops,
&authctxt->krb5_fwd_ccache);
if (problem)
goto out;
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problem = krb5_cc_initialize(authctxt->krb5_ctx,
authctxt->krb5_fwd_ccache, authctxt->krb5_user);
if (problem)
goto out;
restore_uid();
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problem = krb5_verify_user(authctxt->krb5_ctx, authctxt->krb5_user,
authctxt->krb5_fwd_ccache, password, 1, NULL);
temporarily_use_uid(authctxt->pw);
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if (problem)
goto out;
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authctxt->krb5_ticket_file = (char *)krb5_cc_get_name(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache);
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out:
restore_uid();
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if (problem) {
if (authctxt->krb5_ctx != NULL)
debug("Kerberos password authentication failed: %s",
krb5_get_err_text(authctxt->krb5_ctx, problem));
else
debug("Kerberos password authentication failed: %d",
problem);
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krb5_cleanup_proc(authctxt);
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if (options.kerberos_or_local_passwd)
return (-1);
else
return (0);
}
return (1);
}
void
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krb5_cleanup_proc(void *context)
{
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Authctxt *authctxt = (Authctxt *)context;
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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_auth_ctx) {
krb5_auth_con_free(authctxt->krb5_ctx,
authctxt->krb5_auth_ctx);
authctxt->krb5_auth_ctx = NULL;
}
if (authctxt->krb5_ctx) {
krb5_free_context(authctxt->krb5_ctx);
authctxt->krb5_ctx = NULL;
}
}
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#endif /* KRB5 */