[CRYPTO] pcbc: Use crypto_xor
This patch replaces the custom xor in CBC with the generic crypto_xor.
It changes the operations for in-place encryption slightly to avoid
calling crypto_xor with tmpbuf since it is not necessarily aligned.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/pcbc.c b/crypto/pcbc.c
index c3ed8a1..fe70477 100644
--- a/crypto/pcbc.c
+++ b/crypto/pcbc.c
@@ -24,7 +24,6 @@
struct crypto_pcbc_ctx {
struct crypto_cipher *child;
- void (*xor)(u8 *dst, const u8 *src, unsigned int bs);
};
static int crypto_pcbc_setkey(struct crypto_tfm *parent, const u8 *key,
@@ -45,9 +44,7 @@
static int crypto_pcbc_encrypt_segment(struct blkcipher_desc *desc,
struct blkcipher_walk *walk,
- struct crypto_cipher *tfm,
- void (*xor)(u8 *, const u8 *,
- unsigned int))
+ struct crypto_cipher *tfm)
{
void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
crypto_cipher_alg(tfm)->cia_encrypt;
@@ -58,10 +55,10 @@
u8 *iv = walk->iv;
do {
- xor(iv, src, bsize);
+ crypto_xor(iv, src, bsize);
fn(crypto_cipher_tfm(tfm), dst, iv);
memcpy(iv, dst, bsize);
- xor(iv, src, bsize);
+ crypto_xor(iv, src, bsize);
src += bsize;
dst += bsize;
@@ -72,9 +69,7 @@
static int crypto_pcbc_encrypt_inplace(struct blkcipher_desc *desc,
struct blkcipher_walk *walk,
- struct crypto_cipher *tfm,
- void (*xor)(u8 *, const u8 *,
- unsigned int))
+ struct crypto_cipher *tfm)
{
void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
crypto_cipher_alg(tfm)->cia_encrypt;
@@ -86,10 +81,10 @@
do {
memcpy(tmpbuf, src, bsize);
- xor(iv, tmpbuf, bsize);
+ crypto_xor(iv, src, bsize);
fn(crypto_cipher_tfm(tfm), src, iv);
- memcpy(iv, src, bsize);
- xor(iv, tmpbuf, bsize);
+ memcpy(iv, tmpbuf, bsize);
+ crypto_xor(iv, src, bsize);
src += bsize;
} while ((nbytes -= bsize) >= bsize);
@@ -107,7 +102,6 @@
struct crypto_blkcipher *tfm = desc->tfm;
struct crypto_pcbc_ctx *ctx = crypto_blkcipher_ctx(tfm);
struct crypto_cipher *child = ctx->child;
- void (*xor)(u8 *, const u8 *, unsigned int bs) = ctx->xor;
int err;
blkcipher_walk_init(&walk, dst, src, nbytes);
@@ -115,11 +109,11 @@
while ((nbytes = walk.nbytes)) {
if (walk.src.virt.addr == walk.dst.virt.addr)
- nbytes = crypto_pcbc_encrypt_inplace(desc, &walk, child,
- xor);
+ nbytes = crypto_pcbc_encrypt_inplace(desc, &walk,
+ child);
else
- nbytes = crypto_pcbc_encrypt_segment(desc, &walk, child,
- xor);
+ nbytes = crypto_pcbc_encrypt_segment(desc, &walk,
+ child);
err = blkcipher_walk_done(desc, &walk, nbytes);
}
@@ -128,9 +122,7 @@
static int crypto_pcbc_decrypt_segment(struct blkcipher_desc *desc,
struct blkcipher_walk *walk,
- struct crypto_cipher *tfm,
- void (*xor)(u8 *, const u8 *,
- unsigned int))
+ struct crypto_cipher *tfm)
{
void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
crypto_cipher_alg(tfm)->cia_decrypt;
@@ -142,9 +134,9 @@
do {
fn(crypto_cipher_tfm(tfm), dst, src);
- xor(dst, iv, bsize);
+ crypto_xor(dst, iv, bsize);
memcpy(iv, src, bsize);
- xor(iv, dst, bsize);
+ crypto_xor(iv, dst, bsize);
src += bsize;
dst += bsize;
@@ -157,9 +149,7 @@
static int crypto_pcbc_decrypt_inplace(struct blkcipher_desc *desc,
struct blkcipher_walk *walk,
- struct crypto_cipher *tfm,
- void (*xor)(u8 *, const u8 *,
- unsigned int))
+ struct crypto_cipher *tfm)
{
void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
crypto_cipher_alg(tfm)->cia_decrypt;
@@ -172,9 +162,9 @@
do {
memcpy(tmpbuf, src, bsize);
fn(crypto_cipher_tfm(tfm), src, src);
- xor(src, iv, bsize);
+ crypto_xor(src, iv, bsize);
memcpy(iv, tmpbuf, bsize);
- xor(iv, src, bsize);
+ crypto_xor(iv, src, bsize);
src += bsize;
} while ((nbytes -= bsize) >= bsize);
@@ -192,7 +182,6 @@
struct crypto_blkcipher *tfm = desc->tfm;
struct crypto_pcbc_ctx *ctx = crypto_blkcipher_ctx(tfm);
struct crypto_cipher *child = ctx->child;
- void (*xor)(u8 *, const u8 *, unsigned int bs) = ctx->xor;
int err;
blkcipher_walk_init(&walk, dst, src, nbytes);
@@ -200,48 +189,17 @@
while ((nbytes = walk.nbytes)) {
if (walk.src.virt.addr == walk.dst.virt.addr)
- nbytes = crypto_pcbc_decrypt_inplace(desc, &walk, child,
- xor);
+ nbytes = crypto_pcbc_decrypt_inplace(desc, &walk,
+ child);
else
- nbytes = crypto_pcbc_decrypt_segment(desc, &walk, child,
- xor);
+ nbytes = crypto_pcbc_decrypt_segment(desc, &walk,
+ child);
err = blkcipher_walk_done(desc, &walk, nbytes);
}
return err;
}
-static void xor_byte(u8 *a, const u8 *b, unsigned int bs)
-{
- do {
- *a++ ^= *b++;
- } while (--bs);
-}
-
-static void xor_quad(u8 *dst, const u8 *src, unsigned int bs)
-{
- u32 *a = (u32 *)dst;
- u32 *b = (u32 *)src;
-
- do {
- *a++ ^= *b++;
- } while ((bs -= 4));
-}
-
-static void xor_64(u8 *a, const u8 *b, unsigned int bs)
-{
- ((u32 *)a)[0] ^= ((u32 *)b)[0];
- ((u32 *)a)[1] ^= ((u32 *)b)[1];
-}
-
-static void xor_128(u8 *a, const u8 *b, unsigned int bs)
-{
- ((u32 *)a)[0] ^= ((u32 *)b)[0];
- ((u32 *)a)[1] ^= ((u32 *)b)[1];
- ((u32 *)a)[2] ^= ((u32 *)b)[2];
- ((u32 *)a)[3] ^= ((u32 *)b)[3];
-}
-
static int crypto_pcbc_init_tfm(struct crypto_tfm *tfm)
{
struct crypto_instance *inst = (void *)tfm->__crt_alg;
@@ -249,22 +207,6 @@
struct crypto_pcbc_ctx *ctx = crypto_tfm_ctx(tfm);
struct crypto_cipher *cipher;
- switch (crypto_tfm_alg_blocksize(tfm)) {
- case 8:
- ctx->xor = xor_64;
- break;
-
- case 16:
- ctx->xor = xor_128;
- break;
-
- default:
- if (crypto_tfm_alg_blocksize(tfm) % 4)
- ctx->xor = xor_byte;
- else
- ctx->xor = xor_quad;
- }
-
cipher = crypto_spawn_cipher(spawn);
if (IS_ERR(cipher))
return PTR_ERR(cipher);
@@ -304,8 +246,9 @@
inst->alg.cra_alignmask = alg->cra_alignmask;
inst->alg.cra_type = &crypto_blkcipher_type;
- if (!(alg->cra_blocksize % 4))
- inst->alg.cra_alignmask |= 3;
+ /* We access the data as u32s when xoring. */
+ inst->alg.cra_alignmask |= __alignof__(u32) - 1;
+
inst->alg.cra_blkcipher.ivsize = alg->cra_blocksize;
inst->alg.cra_blkcipher.min_keysize = alg->cra_cipher.cia_min_keysize;
inst->alg.cra_blkcipher.max_keysize = alg->cra_cipher.cia_max_keysize;
