source: vendor/current/source4/heimdal/kdc/misc.c

/*
 * Copyright (c) 1997 - 2001 Kungliga Tekniska Högskolan
 * (Royal Institute of Technology, Stockholm, Sweden).
 * 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 the Institute 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 THE INSTITUTE 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 THE INSTITUTE 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 "kdc_locl.h"

struct timeval _kdc_now;

krb5_error_code
_kdc_db_fetch(krb5_context context,
              krb5_kdc_configuration *config,
              krb5_const_principal principal,
              unsigned flags,
              krb5int32 *kvno_ptr,
              HDB **db,
              hdb_entry_ex **h)
{
    hdb_entry_ex *ent;
    krb5_error_code ret = HDB_ERR_NOENTRY;
    int i;
    unsigned kvno = 0;
    krb5_principal enterprise_principal = NULL;
    krb5_const_principal princ;

    *h = NULL;

    if (kvno_ptr) {
            kvno = *kvno_ptr;
            flags |= HDB_F_KVNO_SPECIFIED;
    }

    ent = calloc(1, sizeof (*ent));
    if (ent == NULL)
        return krb5_enomem(context);

    if (principal->name.name_type == KRB5_NT_ENTERPRISE_PRINCIPAL) {
        if (principal->name.name_string.len != 1) {
            ret = KRB5_PARSE_MALFORMED;
            krb5_set_error_message(context, ret,
                                   "malformed request: "
                                   "enterprise name with %d name components",
                                   principal->name.name_string.len);
            goto out;
        }
        ret = krb5_parse_name(context, principal->name.name_string.val[0],
                              &enterprise_principal);
        if (ret)
            goto out;
    }

    for (i = 0; i < config->num_db; i++) {
        ret = config->db[i]->hdb_open(context, config->db[i], O_RDONLY, 0);
        if (ret) {
            const char *msg = krb5_get_error_message(context, ret);
            kdc_log(context, config, 0, "Failed to open database: %s", msg);
            krb5_free_error_message(context, msg);
            continue;
        }

        princ = principal;
        if (!(config->db[i]->hdb_capability_flags & HDB_CAP_F_HANDLE_ENTERPRISE_PRINCIPAL) && enterprise_principal)
            princ = enterprise_principal;

        ret = config->db[i]->hdb_fetch_kvno(context,
                                            config->db[i],
                                            princ,
                                            flags | HDB_F_DECRYPT,
                                            kvno,
                                            ent);
        config->db[i]->hdb_close(context, config->db[i]);

        switch (ret) {
        case HDB_ERR_WRONG_REALM:
            /*
             * the ent->entry.principal just contains hints for the client
             * to retry. This is important for enterprise principal routing
             * between trusts.
             */
            /* fall through */
        case 0:
            if (db)
                *db = config->db[i];
            *h = ent;
            ent = NULL;
            goto out;

        case HDB_ERR_NOENTRY:
            /* Check the other databases */
            continue;

        default:
            /* 
             * This is really important, because errors like
             * HDB_ERR_NOT_FOUND_HERE (used to indicate to Samba that
             * the RODC on which this code is running does not have
             * the key we need, and so a proxy to the KDC is required)
             * have specific meaning, and need to be propogated up.
             */
            goto out;
        }
    }

    if (ret == HDB_ERR_NOENTRY) {
        krb5_set_error_message(context, ret, "no such entry found in hdb");
    }
out:
    krb5_free_principal(context, enterprise_principal);
    free(ent);
    return ret;
}

void
_kdc_free_ent(krb5_context context, hdb_entry_ex *ent)
{
    hdb_free_entry (context, ent);
    free (ent);
}

/*
 * Use the order list of preferred encryption types and sort the
 * available keys and return the most preferred key.
 */

krb5_error_code
_kdc_get_preferred_key(krb5_context context,
                       krb5_kdc_configuration *config,
                       hdb_entry_ex *h,
                       const char *name,
                       krb5_enctype *enctype,
                       Key **key)
{
    krb5_error_code ret;
    int i;

    if (config->use_strongest_server_key) {
        const krb5_enctype *p = krb5_kerberos_enctypes(context);

        for (i = 0; p[i] != ETYPE_NULL; i++) {
            if (krb5_enctype_valid(context, p[i]) != 0)
                continue;
            ret = hdb_enctype2key(context, &h->entry, p[i], key);
            if (ret != 0)
                continue;
            if (enctype != NULL)
                *enctype = p[i];
            return 0;
        }
    } else {
        *key = NULL;

        for (i = 0; i < h->entry.keys.len; i++) {
            if (krb5_enctype_valid(context, h->entry.keys.val[i].key.keytype)
                != 0)
                continue;
            ret = hdb_enctype2key(context, &h->entry,
                h->entry.keys.val[i].key.keytype, key);
            if (ret != 0)
                continue;
            if (enctype != NULL)
                *enctype = (*key)->key.keytype;
            return 0;
        }
    }

    krb5_set_error_message(context, EINVAL,
                           "No valid kerberos key found for %s", name);
    return EINVAL; /* XXX */
}