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/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
/*
* lib/crypto/crypto_length.c
*
* Copyright 2008 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.
*/
#include "crypto_int.h"
krb5_error_code KRB5_CALLCONV
krb5_c_crypto_length(krb5_context context, krb5_enctype enctype,
krb5_cryptotype type, unsigned int *size)
{
const struct krb5_keytypes *ktp;
ktp = find_enctype(enctype);
if (ktp == NULL)
return KRB5_BAD_ENCTYPE;
switch (type) {
case KRB5_CRYPTO_TYPE_EMPTY:
case KRB5_CRYPTO_TYPE_SIGN_ONLY:
*size = 0;
break;
case KRB5_CRYPTO_TYPE_DATA:
*size = (size_t)~0; /* match Heimdal */
break;
case KRB5_CRYPTO_TYPE_HEADER:
case KRB5_CRYPTO_TYPE_PADDING:
case KRB5_CRYPTO_TYPE_TRAILER:
case KRB5_CRYPTO_TYPE_CHECKSUM:
*size = ktp->crypto_length(ktp, type);
break;
default:
return EINVAL;
}
return 0;
}
krb5_error_code KRB5_CALLCONV
krb5_c_padding_length(krb5_context context, krb5_enctype enctype,
size_t data_length, unsigned int *pad_length)
{
const struct krb5_keytypes *ktp;
ktp = find_enctype(enctype);
if (ktp == NULL)
return KRB5_BAD_ENCTYPE;
*pad_length = krb5int_c_padding_length(ktp, data_length);
return 0;
}
krb5_error_code KRB5_CALLCONV
krb5_c_crypto_length_iov(krb5_context context, krb5_enctype enctype,
krb5_crypto_iov *data, size_t num_data)
{
size_t i;
const struct krb5_keytypes *ktp;
unsigned int data_length = 0, pad_length;
krb5_crypto_iov *padding = NULL;
/*
* XXX need to rejig internal interface so we can accurately
* report variable header lengths.
*/
ktp = find_enctype(enctype);
if (ktp == NULL)
return KRB5_BAD_ENCTYPE;
for (i = 0; i < num_data; i++) {
krb5_crypto_iov *iov = &data[i];
switch (iov->flags) {
case KRB5_CRYPTO_TYPE_DATA:
data_length += iov->data.length;
break;
case KRB5_CRYPTO_TYPE_PADDING:
if (padding != NULL)
return EINVAL;
padding = iov;
break;
case KRB5_CRYPTO_TYPE_HEADER:
case KRB5_CRYPTO_TYPE_TRAILER:
case KRB5_CRYPTO_TYPE_CHECKSUM:
iov->data.length = ktp->crypto_length(ktp, iov->flags);
break;
case KRB5_CRYPTO_TYPE_EMPTY:
case KRB5_CRYPTO_TYPE_SIGN_ONLY:
default:
break;
}
}
pad_length = krb5int_c_padding_length(ktp, data_length);
if (pad_length != 0 && padding == NULL)
return EINVAL;
if (padding != NULL)
padding->data.length = pad_length;
return 0;
}
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