acquire.c

/*
 * Copyright (c) 2005, PADL Software Pty Ltd.
 * 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.
 *
 * 3. Neither the name of PADL Software nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY PADL SOFTWARE AND CONTRIBUTORS ``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 PADL SOFTWARE OR CONTRIBUTORS 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 "kcm_locl.h"

/*
 * Get a new ticket using a keytab/cached key and swap it into
 * an existing redentials cache
 */

krb5_error_code
kcm_ccache_acquire(krb5_context context,
		   kcm_ccache ccache,
		   krb5_creds **credp)
{
    krb5_error_code ret = 0;
    krb5_creds cred;
    krb5_const_realm realm;
    krb5_get_init_creds_opt *opt = NULL;
    krb5_ccache_data ccdata;
    char *in_tkt_service = NULL;

    memset(&cred, 0, sizeof(cred));

    KCM_ASSERT_VALID(ccache);

    /* We need a cached key or keytab to acquire credentials */
    if (ccache->flags & KCM_FLAGS_USE_CACHED_KEY) {
	if (ccache->key.keyblock.keyvalue.length == 0)
	    krb5_abortx(context,
			"kcm_ccache_acquire: KCM_FLAGS_USE_CACHED_KEY without key");
    } else if (ccache->flags & KCM_FLAGS_USE_KEYTAB) {
	if (ccache->key.keytab == NULL)
	    krb5_abortx(context,
			"kcm_ccache_acquire: KCM_FLAGS_USE_KEYTAB without keytab");
    } else {
	kcm_log(0, "Cannot acquire initial credentials for cache %s without key",
		ccache->name);
	return KRB5_FCC_INTERNAL;
    }

    HEIMDAL_MUTEX_lock(&ccache->mutex);

    /* Fake up an internal ccache */
    kcm_internal_ccache(context, ccache, &ccdata);

    /* Now, actually acquire the creds */
    if (ccache->server != NULL) {
	ret = krb5_unparse_name(context, ccache->server, &in_tkt_service);
	if (ret) {
	    kcm_log(0, "Failed to unparse service principal name for cache %s: %s",
		    ccache->name, krb5_get_err_text(context, ret));
	    return ret;
	}
    }

    realm = krb5_principal_get_realm(context, ccache->client);

    ret = krb5_get_init_creds_opt_alloc(context, &opt);
    if (ret)
	goto out;
    krb5_get_init_creds_opt_set_default_flags(context, "kcm", realm, opt);
    if (ccache->tkt_life != 0)
	krb5_get_init_creds_opt_set_tkt_life(opt, ccache->tkt_life);
    if (ccache->renew_life != 0)
	krb5_get_init_creds_opt_set_renew_life(opt, ccache->renew_life);

    if (ccache->flags & KCM_FLAGS_USE_CACHED_KEY) {
	ret = krb5_get_init_creds_keyblock(context,
					   &cred,
					   ccache->client,
					   &ccache->key.keyblock,
					   0,
					   in_tkt_service,
					   opt);
    } else {
	/* loosely based on lib/krb5/init_creds_pw.c */
	ret = krb5_get_init_creds_keytab(context,
					 &cred,
					 ccache->client,
					 ccache->key.keytab,
					 0,
					 in_tkt_service,
					 opt);
    }

    if (ret) {
	kcm_log(0, "Failed to acquire credentials for cache %s: %s",
		ccache->name, krb5_get_err_text(context, ret));
	if (in_tkt_service != NULL)
	    free(in_tkt_service);
	goto out;
    }

    if (in_tkt_service != NULL)
	free(in_tkt_service);

    /* Swap them in */
    kcm_ccache_remove_creds_internal(context, ccache);

    ret = kcm_ccache_store_cred_internal(context, ccache, &cred, 0, credp);
    if (ret) {
	kcm_log(0, "Failed to store credentials for cache %s: %s",
		ccache->name, krb5_get_err_text(context, ret));
	krb5_free_cred_contents(context, &cred);
	goto out;
    }

out:
    if (opt)
	krb5_get_init_creds_opt_free(context, opt);

    HEIMDAL_MUTEX_unlock(&ccache->mutex);

    return ret;
}