[CRYPTO] salsa20_generic: Fix multi-page processing
This patch fixes the multi-page processing bug that affects large test
vectors (the same bug that previously affected ctr.c).
There is an optimization for the case walk.nbytes == nbytes. Also we
now use crypto_xor() instead of adhoc XOR routines.
Signed-off-by: Tan Swee Heng <thesweeheng@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/salsa20_generic.c b/crypto/salsa20_generic.c
index b49328a..1fa4e4d 100644
--- a/crypto/salsa20_generic.c
+++ b/crypto/salsa20_generic.c
@@ -143,7 +143,6 @@
const u8 *src, unsigned int bytes)
{
u8 buf[64];
- int i;
if (dst != src)
memcpy(dst, src, bytes);
@@ -156,15 +155,11 @@
ctx->input[9] = PLUSONE(ctx->input[9]);
if (bytes <= 64) {
- for (i = 0; i < bytes/4; ++i)
- ((u32*)dst)[i] ^= ((u32*)buf)[i];
- for (i = bytes - bytes % 4; i < bytes; ++i)
- dst[i] ^= buf[i];
+ crypto_xor(dst, buf, bytes);
return;
}
- for (i = 0; i < 64/4; ++i)
- ((u32*)dst)[i] ^= ((u32*)buf)[i];
+ crypto_xor(dst, buf, 64);
bytes -= 64;
dst += 64;
}
@@ -192,13 +187,30 @@
int err;
blkcipher_walk_init(&walk, dst, src, nbytes);
- err = blkcipher_walk_virt(desc, &walk);
+ err = blkcipher_walk_virt_block(desc, &walk, 64);
salsa20_ivsetup(ctx, walk.iv);
- salsa20_encrypt_bytes(ctx, walk.dst.virt.addr,
- walk.src.virt.addr, nbytes);
- err = blkcipher_walk_done(desc, &walk, 0);
+ if (likely(walk.nbytes == nbytes))
+ {
+ salsa20_encrypt_bytes(ctx, walk.dst.virt.addr,
+ walk.src.virt.addr, nbytes);
+ return blkcipher_walk_done(desc, &walk, 0);
+ }
+
+ while (walk.nbytes >= 64) {
+ salsa20_encrypt_bytes(ctx, walk.dst.virt.addr,
+ walk.src.virt.addr,
+ walk.nbytes - (walk.nbytes % 64));
+ err = blkcipher_walk_done(desc, &walk, walk.nbytes % 64);
+ }
+
+ if (walk.nbytes) {
+ salsa20_encrypt_bytes(ctx, walk.dst.virt.addr,
+ walk.src.virt.addr, walk.nbytes);
+ err = blkcipher_walk_done(desc, &walk, 0);
+ }
+
return err;
}