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Commit 7632451a authored by Vitaly Chikunov's avatar Vitaly Chikunov Committed by Greg Kroah-Hartman
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crypto: ecrdsa - Fix incorrect use of vli_cmp 



commit 7cc7ab73f83ee6d50dc9536bc3355495d8600fad upstream.

Correctly compare values that shall be greater-or-equal and not just
greater.

Fixes: 0d7a7864 ("crypto: ecrdsa - add EC-RDSA (GOST 34.10) algorithm")
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarVitaly Chikunov <vt@altlinux.org>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent b16bb373

crypto/ecrdsa.c

+4 −4
Original line number Diff line number Diff line
@@ -112,15 +112,15 @@ static int ecrdsa_verify(struct akcipher_request *req) 


	/* Step 1: verify that 0 < r < q, 0 < s < q */

	if (vli_is_zero(r, ndigits) ||

	    vli_cmp(r, ctx->curve->n, ndigits) == 1 ||

	    vli_cmp(r, ctx->curve->n, ndigits) >= 0 ||

	    vli_is_zero(s, ndigits) ||

	    vli_cmp(s, ctx->curve->n, ndigits) == 1)

	    vli_cmp(s, ctx->curve->n, ndigits) >= 0)

		return -EKEYREJECTED;



	/* Step 2: calculate hash (h) of the message (passed as input) */

	/* Step 3: calculate e = h \mod q */

	vli_from_le64(e, digest, ndigits);

	if (vli_cmp(e, ctx->curve->n, ndigits) == 1)

	if (vli_cmp(e, ctx->curve->n, ndigits) >= 0)

		vli_sub(e, e, ctx->curve->n, ndigits);

	if (vli_is_zero(e, ndigits))

		e[0] = 1;
@@ -136,7 +136,7 @@ static int ecrdsa_verify(struct akcipher_request *req) 
	/* Step 6: calculate point C = z_1P + z_2Q, and R = x_c \mod q */

	ecc_point_mult_shamir(&cc, z1, &ctx->curve->g, z2, &ctx->pub_key,

			      ctx->curve);

	if (vli_cmp(cc.x, ctx->curve->n, ndigits) == 1)

	if (vli_cmp(cc.x, ctx->curve->n, ndigits) >= 0)

		vli_sub(cc.x, cc.x, ctx->curve->n, ndigits);



	/* Step 7: if R == r signature is valid */