Commit f398243e authored Oct 23, 2019 by Ard Biesheuvel Committed by Herbert Xu Nov 01, 2019

crypto: ecdh - fix big endian bug in ECC library

The elliptic curve arithmetic library used by the EC-DH KPP implementation
assumes big endian byte order, and unconditionally reverses the byte
and word order of multi-limb quantities. On big endian systems, the byte
reordering is not necessary, while the word ordering needs to be retained.

So replace the __swab64() invocation with a call to be64_to_cpu() which
should do the right thing for both little and big endian builds.

Fixes: 3c4b2390 ("crypto: ecdh - Add ECDH software support")
Cc: <stable@vger.kernel.org> # v4.9+
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

parent 51d13aaf

crypto/ecc.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -1284,10 +1284,11 @@ EXPORT_SYMBOL(ecc_point_mult_shamir);
		static inline void ecc_swap_digits(const u64 in, u64 out,
		unsigned int ndigits)
		{
		const __be64 src = (__force __be64 )in;
		int i;

		for (i = 0; i < ndigits; i++)
		out[i] = __swab64(in[ndigits - 1 - i]);
		out[i] = be64_to_cpu(src[ndigits - 1 - i]);
		}

		static int __ecc_is_key_valid(const struct ecc_curve *curve,

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