Commit 0ae86992 authored by Meng Yu's avatar Meng Yu Committed by Herbert Xu
Browse files

crypto: hisilicon/hpre - Add processing of src_data in 'CURVE25519' 



HPRE can only deal with src_data smaller than 'p' in 'CURVE25519'
algorithm, but 'rfc7748' says:
'Implementations MUST accept non-canonical values and process them as
if they had been reduced modulo the field prime'
So we get its modulus to p, and then deal it with HPRE.

Signed-off-by: default avatarMeng Yu <yumeng18@huawei.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 9bb3fbbf

drivers/crypto/hisilicon/hpre/hpre_crypto.c

+18 −4
Original line number Diff line number Diff line
@@ -1729,6 +1729,17 @@ static int hpre_curve25519_msg_request_set(struct hpre_ctx *ctx, 
	return 0;

}



static void hpre_curve25519_src_modulo_p(u8 *ptr)

{

	int i;



	for (i = 0; i < CURVE25519_KEY_SIZE - 1; i++)

		ptr[i] = 0;



	/* The modulus is ptr's last byte minus '0xed'(last byte of p) */

	ptr[i] -= 0xed;

}



static int hpre_curve25519_src_init(struct hpre_asym_request *hpre_req,

				    struct scatterlist *data, unsigned int len)

{
@@ -1767,10 +1778,13 @@ static int hpre_curve25519_src_init(struct hpre_asym_request *hpre_req, 
	curve = ecc_get_curve25519();



	fill_curve_param(p, curve->p, CURVE25519_KEY_SIZE, curve->g.ndigits);

	if (memcmp(ptr, p, ctx->key_sz) >= 0) {

		dev_err(dev, "gx is out of p!\n");

		goto err;

	}



	/*

	 * When src_data equals (2^255 - 19) ~  (2^255 - 1), it is out of p,

	 * we get its modulus to p, and then use it.

	 */

	if (memcmp(ptr, p, ctx->key_sz) >= 0)

		hpre_curve25519_src_modulo_p(ptr);



	hpre_req->src = ptr;

	msg->in = cpu_to_le64(dma);