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kernel
os
linux
crypto: ecrdsa - Fix incorrect use of vli_cmp
Correctly compare values that shall be greater-or-equal and not just
greater.
Fixes: 0d7a78643f69 ("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>
authored by
Vitaly Chikunov
and committed by
Herbert Xu
7cc7ab73
4ee4cdad
+4
-4
+4
-4
crypto/ecrdsa.c
+4
-4
crypto/ecrdsa.c
···
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/* Step 1: verify that 0 < r < q, 0 < s < q */
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if (vli_is_zero(r, ndigits) ||
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-
vli_cmp(r, ctx->curve->n, ndigits) == 1 ||
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+
vli_cmp(r, ctx->curve->n, ndigits) >= 0 ||
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vli_is_zero(s, ndigits) ||
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-
vli_cmp(s, ctx->curve->n, ndigits) == 1)
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+
vli_cmp(s, ctx->curve->n, ndigits) >= 0)
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return -EKEYREJECTED;
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/* Step 2: calculate hash (h) of the message (passed as input) */
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/* Step 3: calculate e = h \mod q */
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vli_from_le64(e, digest, ndigits);
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if (vli_cmp(e, ctx->curve->n, ndigits) == 1)
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+
if (vli_cmp(e, ctx->curve->n, ndigits) >= 0)
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vli_sub(e, e, ctx->curve->n, ndigits);
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if (vli_is_zero(e, ndigits))
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e[0] = 1;
···
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/* Step 6: calculate point C = z_1P + z_2Q, and R = x_c \mod q */
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ecc_point_mult_shamir(&cc, z1, &ctx->curve->g, z2, &ctx->pub_key,
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ctx->curve);
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if (vli_cmp(cc.x, ctx->curve->n, ndigits) == 1)
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if (vli_cmp(cc.x, ctx->curve->n, ndigits) >= 0)
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vli_sub(cc.x, cc.x, ctx->curve->n, ndigits);
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/* Step 7: if R == r signature is valid */