/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */

/*

 * Copyright (C) 1998 by the FundsXpress, INC.

 *

 * 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 FundsXpress. not be used in advertising or publicity pertaining

 * to distribution of the software without specific, written prior

 * permission.  FundsXpress makes no representations about the suitability of

 * this software for any purpose.  It is provided "as is" without express

 * or implied warranty.

 *

 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR

 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED

 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.

 */

#include "crypto_int.h"

#include "des_int.h"

static krb5_error_code

validate_and_schedule(krb5_key key, const krb5_data *ivec,

                      const krb5_crypto_iov *data, size_t num_data,

                      mit_des3_key_schedule *schedule)

{

    if (key->keyblock.length != 24)

        return(KRB5_BAD_KEYSIZE);

    if (iov_total_length(data, num_data, FALSE) % 8 != 0)

        return(KRB5_BAD_MSIZE);

    if (ivec && (ivec->length != 8))

        return(KRB5_BAD_MSIZE);

    switch (mit_des3_key_sched(*(mit_des3_cblock *)key->keyblock.contents,

                               *schedule)) {

    case -1:

        return(KRB5DES_BAD_KEYPAR);

    case -2:

        return(KRB5DES_WEAK_KEY);

    }

    return 0;

}

static krb5_error_code

k5_des3_encrypt(krb5_key key, const krb5_data *ivec, krb5_crypto_iov *data,

                size_t num_data)

{

    mit_des3_key_schedule schedule;

    krb5_error_code err;

    err = validate_and_schedule(key, ivec, data, num_data, &schedule);

    if (err)

        return err;

    /* this has a return value, but the code always returns zero */

    krb5int_des3_cbc_encrypt(data, num_data,

                             schedule[0], schedule[1], schedule[2],

                             ivec != NULL ? (unsigned char *) ivec->data :

                             NULL);

    zap(schedule, sizeof(schedule));

    return(0);

}

static krb5_error_code

k5_des3_decrypt(krb5_key key, const krb5_data *ivec, krb5_crypto_iov *data,

                size_t num_data)

{

    mit_des3_key_schedule schedule;

    krb5_error_code err;

    err = validate_and_schedule(key, ivec, data, num_data, &schedule);

    if (err)

        return err;

    /* this has a return value, but the code always returns zero */

    krb5int_des3_cbc_decrypt(data, num_data,

                             schedule[0], schedule[1], schedule[2],

                             ivec != NULL ? (unsigned char *) ivec->data :

                             NULL);

    zap(schedule, sizeof(schedule));

    return 0;

}

const struct krb5_enc_provider krb5int_enc_des3 = {

    8,

    21, 24,

    k5_des3_encrypt,

    k5_des3_decrypt,

    NULL,

    krb5int_des_init_state,

    krb5int_default_free_state

};