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[CRYPTO] salsa20_generic: Fix multi-page processing

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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>
This commit is contained in:
Tan Swee Heng 2007-12-07 16:38:45 +08:00 committed by Herbert Xu
parent 7f6813786a
commit eb6f13eb9f
1 changed files with 23 additions and 11 deletions
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34
crypto/salsa20_generic.c
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@ -143,7 +143,6 @@ static void salsa20_encrypt_bytes(struct salsa20_ctx *ctx, u8 *dst,
const u8 *src, unsigned int bytes)
{
u8 buf[64];
int i;
if (dst != src)
memcpy(dst, src, bytes);
@ -156,15 +155,11 @@ static void salsa20_encrypt_bytes(struct salsa20_ctx *ctx, u8 *dst,
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 @@ static int encrypt(struct blkcipher_desc *desc,
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;
}