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// SPDX-License-Identifier: BSD-2-Clause
/*
* Copyright 2018-2020 NXP
*
* Brief Cryptographic library using the NXP CAAM driver.
* Mathematical Modulus operation implementation.
*/
#include <drvcrypt.h>
#include <drvcrypt_math.h>
#include <string.h>
#include <util.h>
TEE_Result drvcrypt_xor_mod_n(struct drvcrypt_mod_op *data)
{
TEE_Result ret = TEE_ERROR_GENERIC;
struct drvcrypt_math *math = NULL;
if (!data->a.data || !data->a.length || !data->b.data ||
!data->b.length || !data->result.data || !data->result.length ||
!data->n.length)
return TEE_ERROR_BAD_PARAMETERS;
if (data->result.length < data->n.length)
return TEE_ERROR_BAD_PARAMETERS;
math = drvcrypt_get_ops(CRYPTO_MATH);
if (math) {
/* Operation done by Math driver */
ret = math->xor_mod_n(data);
} else {
/* Operation done by Software */
size_t min = 0, idx = 0;
/* Calculate the minimum size to do A xor B */
min = MIN(data->a.length, data->b.length);
min = MIN(min, data->n.length);
for (; idx < min; idx++)
data->result.data[idx] =
data->a.data[idx] ^ data->b.data[idx];
if (min < data->n.length) {
/* Complete result to make a N modulus number */
if (data->a.length > min) {
memcpy(&data->result.data[idx],
&data->a.data[idx],
data->n.length - min);
} else if (data->b.length > min) {
memcpy(&data->result.data[idx],
&data->b.data[idx],
data->n.length - min);
} else {
memset(&data->result.data[idx], 0,
data->n.length - min);
}
}
ret = TEE_SUCCESS;
}
return ret;
}
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