Re: [Qemu-devel] [PATCH 5/6] crypto: convert xts_mult_x to use xts_uint128 type

[Alberto Garcia]

On Tue 09 Oct 2018 02:55:40 PM CEST, Daniel P. Berrangé wrote:
> -static void xts_mult_x(uint8_t *I)
> +static void xts_mult_x(xts_uint128 *I)
>  {
> -    int x;
> -    uint8_t t, tt;
> +    uint64_t tt;
>  
> -    for (x = t = 0; x < 16; x++) {
> -        tt = I[x] >> 7;
> -        I[x] = ((I[x] << 1) | t) & 0xFF;
> -        t = tt;
> -    }
> -    if (tt) {
> -        I[0] ^= 0x87;
> +    tt = I->a >> 63;
> +    I->a = I->a << 1;
> +
> +    if (I->b >> 63) {
> +        I->a ^= 0x87;
>      }
> +    I->b = (I->b << 1) | tt;
>  }

Does this work fine in big-endian CPUs?

Berto