Hi
On Tue, Oct 9, 2018 at 4:56 PM Daniel P. Berrangé <berra...@redhat.com> wrote:
>
> The tweak encrypt/decrypt functions are identical except for the
> comments, so can be merged. Profiling data shows that the compiler is
> in fact already merging the two merges in the object files.
>
> Signed-off-by: Daniel P. Berrangé <berra...@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lur...@redhat.com>
> ---
> crypto/xts.c | 64 ++++++++++++----------------------------------------
> 1 file changed, 15 insertions(+), 49 deletions(-)
>
> diff --git a/crypto/xts.c b/crypto/xts.c
> index 95212341f6..3c1a92f01d 100644
> --- a/crypto/xts.c
> +++ b/crypto/xts.c
> @@ -43,20 +43,20 @@ static void xts_mult_x(uint8_t *I)
>
>
> /**
> - * xts_tweak_uncrypt:
> + * xts_tweak_encdec:
> * @param ctxt: the cipher context
> * @param func: the cipher function
> - * @src: buffer providing the cipher text of XTS_BLOCK_SIZE bytes
> - * @dst: buffer to output the plain text of XTS_BLOCK_SIZE bytes
> + * @src: buffer providing the input text of XTS_BLOCK_SIZE bytes
> + * @dst: buffer to output the output text of XTS_BLOCK_SIZE bytes
> * @iv: the initialization vector tweak of XTS_BLOCK_SIZE bytes
> *
> - * Decrypt data with a tweak
> + * Encrypt/decrypt data with a tweak
> */
> -static void xts_tweak_decrypt(const void *ctx,
> - xts_cipher_func *func,
> - const uint8_t *src,
> - uint8_t *dst,
> - uint8_t *iv)
> +static void xts_tweak_encdec(const void *ctx,
> + xts_cipher_func *func,
> + const uint8_t *src,
> + uint8_t *dst,
> + uint8_t *iv)
> {
> unsigned long x;
>
> @@ -105,7 +105,7 @@ void xts_decrypt(const void *datactx,
> encfunc(tweakctx, XTS_BLOCK_SIZE, T, iv);
>
> for (i = 0; i < lim; i++) {
> - xts_tweak_decrypt(datactx, decfunc, src, dst, T);
> + xts_tweak_encdec(datactx, decfunc, src, dst, T);
>
> src += XTS_BLOCK_SIZE;
> dst += XTS_BLOCK_SIZE;
> @@ -117,7 +117,7 @@ void xts_decrypt(const void *datactx,
> xts_mult_x(CC);
>
> /* PP = tweak decrypt block m-1 */
> - xts_tweak_decrypt(datactx, decfunc, src, PP, CC);
> + xts_tweak_encdec(datactx, decfunc, src, PP, CC);
>
> /* Pm = first length % XTS_BLOCK_SIZE bytes of PP */
> for (i = 0; i < mo; i++) {
> @@ -129,7 +129,7 @@ void xts_decrypt(const void *datactx,
> }
>
> /* Pm-1 = Tweak uncrypt CC */
> - xts_tweak_decrypt(datactx, decfunc, CC, dst, T);
> + xts_tweak_encdec(datactx, decfunc, CC, dst, T);
> }
>
> /* Decrypt the iv back */
> @@ -137,40 +137,6 @@ void xts_decrypt(const void *datactx,
> }
>
>
> -/**
> - * xts_tweak_crypt:
> - * @param ctxt: the cipher context
> - * @param func: the cipher function
> - * @src: buffer providing the plain text of XTS_BLOCK_SIZE bytes
> - * @dst: buffer to output the cipher text of XTS_BLOCK_SIZE bytes
> - * @iv: the initialization vector tweak of XTS_BLOCK_SIZE bytes
> - *
> - * Encrypt data with a tweak
> - */
> -static void xts_tweak_encrypt(const void *ctx,
> - xts_cipher_func *func,
> - const uint8_t *src,
> - uint8_t *dst,
> - uint8_t *iv)
> -{
> - unsigned long x;
> -
> - /* tweak encrypt block i */
> - for (x = 0; x < XTS_BLOCK_SIZE; x++) {
> - dst[x] = src[x] ^ iv[x];
> - }
> -
> - func(ctx, XTS_BLOCK_SIZE, dst, dst);
> -
> - for (x = 0; x < XTS_BLOCK_SIZE; x++) {
> - dst[x] = dst[x] ^ iv[x];
> - }
> -
> - /* LFSR the tweak */
> - xts_mult_x(iv);
> -}
> -
> -
> void xts_encrypt(const void *datactx,
> const void *tweakctx,
> xts_cipher_func *encfunc,
> @@ -200,7 +166,7 @@ void xts_encrypt(const void *datactx,
> encfunc(tweakctx, XTS_BLOCK_SIZE, T, iv);
>
> for (i = 0; i < lim; i++) {
> - xts_tweak_encrypt(datactx, encfunc, src, dst, T);
> + xts_tweak_encdec(datactx, encfunc, src, dst, T);
>
> dst += XTS_BLOCK_SIZE;
> src += XTS_BLOCK_SIZE;
> @@ -209,7 +175,7 @@ void xts_encrypt(const void *datactx,
> /* if length is not a multiple of XTS_BLOCK_SIZE then */
> if (mo > 0) {
> /* CC = tweak encrypt block m-1 */
> - xts_tweak_encrypt(datactx, encfunc, src, CC, T);
> + xts_tweak_encdec(datactx, encfunc, src, CC, T);
>
> /* Cm = first length % XTS_BLOCK_SIZE bytes of CC */
> for (i = 0; i < mo; i++) {
> @@ -222,7 +188,7 @@ void xts_encrypt(const void *datactx,
> }
>
> /* Cm-1 = Tweak encrypt PP */
> - xts_tweak_encrypt(datactx, encfunc, PP, dst, T);
> + xts_tweak_encdec(datactx, encfunc, PP, dst, T);
> }
>
> /* Decrypt the iv back */
> --
> 2.17.1
>
>
--
Marc-André Lureau
