srv_dec_tkt.c   [plain text]

/*
 * lib/krb5/krb/srv_dec_tkt.c
 *
 * Copyright 2006 by the Massachusetts Institute of Technology.
 * All Rights Reserved.
 *
 * Export of this software from the United States of America may
 *   require a specific license from the United States Government.
 *   It is the responsibility of any person or organization contemplating
 *   export to obtain such a license before exporting.
 *
 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
 * distribute this software and its documentation for any purpose and
 * without fee is hereby granted, provided that the above copyright
 * notice appear in all copies and that both that copyright notice and
 * this permission notice appear in supporting documentation, and that
 * the name of M.I.T. not be used in advertising or publicity pertaining
 * to distribution of the software without specific, written prior
 * permission.  Furthermore if you modify this software you must label
 * your software as modified software and not distribute it in such a
 * fashion that it might be confused with the original M.I.T. software.
 * M.I.T. makes no representations about the suitability of
 * this software for any purpose.  It is provided "as is" without express
 * or implied warranty.
 *
 *
 * Server decrypt ticket via keytab or keyblock. 
 *
 * Different from krb5_rd_req_decoded. (krb5/src/lib/krb5/krb/rd_req_dec.c)
 *   - No krb5_principal_compare or KRB5KRB_AP_ERR_BADMATCH error.
 *   - No replay cache processing.
 *   - No skew checking or KRB5KRB_AP_ERR_SKEW error.
 *   - No address checking or KRB5KRB_AP_ERR_BADADDR error.
 *   - No time validation.
 *   - No permitted enctype validation or KRB5_NOPERM_ETYPE error.
 *   - Does not free ticket->enc_part2 on error. 
 */

#include <k5-int.h>

krb5_error_code KRB5_CALLCONV
krb5int_server_decrypt_ticket_keyblock(krb5_context context,
				       const krb5_keyblock *key,
				       krb5_ticket *ticket)
{
    krb5_error_code retval;
    krb5_data *realm;
    krb5_transited *trans;

    retval = krb5_decrypt_tkt_part(context, key, ticket);
    if (retval) 
	goto done;

    trans = &ticket->enc_part2->transited;
    realm = &ticket->enc_part2->client->realm;
    if (trans->tr_contents.data && *trans->tr_contents.data) {
	retval = krb5_check_transited_list(context, &trans->tr_contents,
					   realm, &ticket->server->realm);
	goto done;
    }

    if (ticket->enc_part2->flags & TKT_FLG_INVALID) {	/* ie, KDC_OPT_POSTDATED */
	retval = KRB5KRB_AP_ERR_TKT_INVALID;
	goto done;
    }

  done:
    return retval;
}


krb5_error_code	KRB5_CALLCONV
krb5_server_decrypt_ticket_keytab(krb5_context context,
				  const krb5_keytab kt,
				  krb5_ticket *ticket)
{
    krb5_error_code       retval;
    krb5_enctype          enctype;
    krb5_keytab_entry     ktent;

    enctype = ticket->enc_part.enctype;

    if ((retval = krb5_kt_get_entry(context, kt, ticket->server,
                                    ticket->enc_part.kvno,
                                    enctype, &ktent)))
        return retval;

    retval = krb5int_server_decrypt_ticket_keyblock(context,
						    &ktent.key, ticket);
    /* Upon error, Free keytab entry first, then return */

    (void) krb5_kt_free_entry(context, &ktent);
    return retval;
}