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crypto: ecrdsa - Fix incorrect use of vli_cmp 

commit 7cc7ab73f8 upstream.

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

Fixes: 0d7a78643f ("crypto: ecrdsa - add EC-RDSA (GOST 34.10) algorithm")
Cc: <stable@vger.kernel.org>
Signed-off-by: Vitaly Chikunov <vt@altlinux.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Vitaly Chikunov 2022-04-21 20:25:10 +03:00 committed by Greg Kroah-Hartman
parent 6daab1a988
commit 6626f026ab
1 changed files with 4 additions and 4 deletions
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8
crypto/ecrdsa.c
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@ -113,15 +113,15 @@ 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;
@ -137,7 +137,7 @@ 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 */