source: heimdal/trunk/kcm/client.c@ 5

/*
 * Copyright (c) 2005, PADL Software Pty Ltd.
 * All rights reserved.
 *
 * Portions Copyright (c) 2009 Apple Inc. 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"
#include <pwd.h>

krb5_error_code
kcm_ccache_resolve_client(krb5_context context,
                          kcm_client *client,
                          kcm_operation opcode,
                          const char *name,
                          kcm_ccache *ccache)
{
    krb5_error_code ret;

    ret = kcm_ccache_resolve(context, name, ccache);
    if (ret) {
        kcm_log(1, "Failed to resolve cache %s: %s",
                name, krb5_get_err_text(context, ret));
        return ret;
    }

    ret = kcm_access(context, client, opcode, *ccache);
    if (ret) {
        ret = KRB5_FCC_NOFILE; /* don't disclose */
        kcm_release_ccache(context, *ccache);
    }

    return ret;
}

krb5_error_code
kcm_ccache_destroy_client(krb5_context context,
                          kcm_client *client,
                          const char *name)
{
    krb5_error_code ret;
    kcm_ccache ccache;

    ret = kcm_ccache_resolve(context, name, &ccache);
    if (ret) {
        kcm_log(1, "Failed to resolve cache %s: %s",
                name, krb5_get_err_text(context, ret));
        return ret;
    }

    ret = kcm_access(context, client, KCM_OP_DESTROY, ccache);
    kcm_cleanup_events(context, ccache);
    kcm_release_ccache(context, ccache);
    if (ret)
        return ret;

    return kcm_ccache_destroy(context, name);
}

krb5_error_code
kcm_ccache_new_client(krb5_context context,
                      kcm_client *client,
                      const char *name,
                      kcm_ccache *ccache_p)
{
    krb5_error_code ret;
    kcm_ccache ccache;

    /* We insist the ccache name starts with UID or UID: */
    if (name_constraints != 0) {
        char prefix[64];
        size_t prefix_len;
        int bad = 1;

        snprintf(prefix, sizeof(prefix), "%ld:", (long)client->uid);
        prefix_len = strlen(prefix);

        if (strncmp(name, prefix, prefix_len) == 0)
            bad = 0;
        else {
            prefix[prefix_len - 1] = '\0';
            if (strcmp(name, prefix) == 0)
                bad = 0;
        }

        /* Allow root to create badly-named ccaches */
        if (bad && !CLIENT_IS_ROOT(client))
            return KRB5_CC_BADNAME;
    }

    ret = kcm_ccache_resolve(context, name, &ccache);
    if (ret == 0) {
        if ((ccache->uid != client->uid ||
             ccache->gid != client->gid) && !CLIENT_IS_ROOT(client))
            return KRB5_FCC_PERM;
    } else if (ret != KRB5_FCC_NOFILE && !(CLIENT_IS_ROOT(client) && ret == KRB5_FCC_PERM)) {
                return ret;
    }

    if (ret == KRB5_FCC_NOFILE) {
        ret = kcm_ccache_new(context, name, &ccache);
        if (ret) {
            kcm_log(1, "Failed to initialize cache %s: %s",
                    name, krb5_get_err_text(context, ret));
            return ret;
        }

        /* bind to current client */
        ccache->uid = client->uid;
        ccache->gid = client->gid;
        ccache->session = client->session;
    } else {
        ret = kcm_zero_ccache_data(context, ccache);
        if (ret) {
            kcm_log(1, "Failed to empty cache %s: %s",
                    name, krb5_get_err_text(context, ret));
            kcm_release_ccache(context, ccache);
            return ret;
        }
        kcm_cleanup_events(context, ccache);
    }

    ret = kcm_access(context, client, KCM_OP_INITIALIZE, ccache);
    if (ret) {
        kcm_release_ccache(context, ccache);
        kcm_ccache_destroy(context, name);
        return ret;
    }

    /*
     * Finally, if the user is root and the cache was created under
     * another user's name, chown the cache to that user and their
     * default gid.
     */
    if (CLIENT_IS_ROOT(client)) {
        unsigned long uid;
        int matches = sscanf(name,"%ld:",&uid);
        if (matches == 0)
            matches = sscanf(name,"%ld",&uid);
        if (matches == 1) {
            struct passwd *pwd = getpwuid(uid);
            if (pwd != NULL) {
                gid_t gid = pwd->pw_gid;
                kcm_chown(context, client, ccache, uid, gid);
            }
        }
    }

    *ccache_p = ccache;
    return 0;
}