The aligned versions are suitable as this hash sets alignmask = 3
so the iv and key passed in will be 4-byte aligned.
Signed-off-by: Harvey Harrison <[email protected]>
---
Herbert, as requested this is the aligned version. Apologies for the
idiotic MAKE_U32 macro....I wanted to make sure this gets done at compile
time. I hope the comment is sufficient, please feel free to suggest something
better and I'll revise. Other than that wart, it is pretty simple.
This depends on the load/store api which is -mm only, so don't apply directly
until the helpers are upstream.
crypto/salsa20_generic.c | 60 ++++++++++++++++++++++++---------------------
1 files changed, 32 insertions(+), 28 deletions(-)
diff --git a/crypto/salsa20_generic.c b/crypto/salsa20_generic.c
index eac10c1..93ea772 100644
--- a/crypto/salsa20_generic.c
+++ b/crypto/salsa20_generic.c
@@ -43,13 +43,6 @@ D. J. Bernstein
Public domain.
*/
-#define U32TO8_LITTLE(p, v) \
- { (p)[0] = (v >> 0) & 0xff; (p)[1] = (v >> 8) & 0xff; \
- (p)[2] = (v >> 16) & 0xff; (p)[3] = (v >> 24) & 0xff; }
-#define U8TO32_LITTLE(p) \
- (((u32)((p)[0]) ) | ((u32)((p)[1]) << 8) | \
- ((u32)((p)[2]) << 16) | ((u32)((p)[3]) << 24) )
-
struct salsa20_ctx
{
u32 input[16];
@@ -98,40 +91,51 @@ static void salsa20_wordtobyte(u8 output[64], const u32 input[16])
for (i = 0; i < 16; ++i)
x[i] += input[i];
for (i = 0; i < 16; ++i)
- U32TO8_LITTLE(output + 4 * i,x[i]);
+ store_le32((__le32 *)(output + 4 * i), x[i]);
}
-static const char sigma[16] = "expand 32-byte k";
-static const char tau[16] = "expand 16-byte k";
-
static void salsa20_keysetup(struct salsa20_ctx *ctx, const u8 *k, u32 kbytes)
{
- const char *constants;
+ int usesigma;
- ctx->input[1] = U8TO32_LITTLE(k + 0);
- ctx->input[2] = U8TO32_LITTLE(k + 4);
- ctx->input[3] = U8TO32_LITTLE(k + 8);
- ctx->input[4] = U8TO32_LITTLE(k + 12);
+ ctx->input[1] = load_le32((__le32 *)(k + 0));
+ ctx->input[2] = load_le32((__le32 *)(k + 4));
+ ctx->input[3] = load_le32((__le32 *)(k + 8));
+ ctx->input[4] = load_le32((__le32 *)(k + 12));
if (kbytes == 32) { /* recommended */
k += 16;
- constants = sigma;
+ usesigma = 1;
} else { /* kbytes == 16 */
- constants = tau;
+ usesigma = 0;
+ }
+ ctx->input[11] = load_le32((__le32 *)(k + 0));
+ ctx->input[12] = load_le32((__le32 *)(k + 4));
+ ctx->input[13] = load_le32((__le32 *)(k + 8));
+ ctx->input[14] = load_le32((__le32 *)(k + 12));
+ /*
+ * Choice of two similar strings used in initialization:
+ * sigma - "expand 32-byte k"
+ * tau - "expand 16-byte k"
+ * which differ only in bytes 7-8. (16 vs 32)
+ */
+#define MAKE_U32(s) ((u32)(s[0]) | ((u32)(s[1]) << 8) | \
+ ((u32)(s[2]) << 16) | ((u32)(s[3]) << 24))
+ ctx->input[ 0] = MAKE_U32("expa");
+ if (usesigma) {
+ ctx->input[ 5] = MAKE_U32("nd 3");
+ ctx->input[10] = MAKE_U32("2-by");
+ } else {
+ ctx->input[ 5] = MAKE_U32("nd 1");
+ ctx->input[10] = MAKE_U32("6-by");
}
- ctx->input[11] = U8TO32_LITTLE(k + 0);
- ctx->input[12] = U8TO32_LITTLE(k + 4);
- ctx->input[13] = U8TO32_LITTLE(k + 8);
- ctx->input[14] = U8TO32_LITTLE(k + 12);
- ctx->input[0] = U8TO32_LITTLE(constants + 0);
- ctx->input[5] = U8TO32_LITTLE(constants + 4);
- ctx->input[10] = U8TO32_LITTLE(constants + 8);
- ctx->input[15] = U8TO32_LITTLE(constants + 12);
+ ctx->input[15] = MAKE_U32("te k");
+#undef MAKE_U32
}
static void salsa20_ivsetup(struct salsa20_ctx *ctx, const u8 *iv)
{
- ctx->input[6] = U8TO32_LITTLE(iv + 0);
- ctx->input[7] = U8TO32_LITTLE(iv + 4);
+ ctx->input[6] = load_le32((__le32 *)(iv + 0));
+ ctx->input[7] = load_le32((__le32 *)(iv + 4));
ctx->input[8] = 0;
ctx->input[9] = 0;
}
--
1.6.1.rc2.282.ga5881
On Mon, Dec 08, 2008 at 05:26:36PM -0800, Harvey Harrison wrote:
>
> @@ -98,40 +91,51 @@ static void salsa20_wordtobyte(u8 output[64], const u32 input[16])
> for (i = 0; i < 16; ++i)
> x[i] += input[i];
> for (i = 0; i < 16; ++i)
> - U32TO8_LITTLE(output + 4 * i,x[i]);
> + store_le32((__le32 *)(output + 4 * i), x[i]);
> }
We need to mark output (i.e., buf) as aligned in the caller.
Otherwise the patch looks good to me.
Thanks,
--
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt