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Commit d0b9007a authored by Herbert Xu's avatar Herbert Xu
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[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: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 50b6544e
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Showing with 24 additions and 81 deletions
crypto/pcbc.c
View file @ d0b9007a
......@@ -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_setkey(struct crypto_tfm *parent, const u8 *key,
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 @@ static int crypto_pcbc_encrypt_segment(struct blkcipher_desc *desc,
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_segment(struct blkcipher_desc *desc,
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 @@ static int crypto_pcbc_encrypt_inplace(struct blkcipher_desc *desc,
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 @@ static int crypto_pcbc_encrypt(struct blkcipher_desc *desc,
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 @@ static int crypto_pcbc_encrypt(struct blkcipher_desc *desc,
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_encrypt(struct blkcipher_desc *desc,
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 @@ static int crypto_pcbc_decrypt_segment(struct blkcipher_desc *desc,
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_segment(struct blkcipher_desc *desc,
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 @@ static int crypto_pcbc_decrypt_inplace(struct blkcipher_desc *desc,
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 @@ static int crypto_pcbc_decrypt(struct blkcipher_desc *desc,
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 @@ static int crypto_pcbc_decrypt(struct blkcipher_desc *desc,
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 @@ static int crypto_pcbc_init_tfm(struct crypto_tfm *tfm)
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 @@ static struct crypto_instance *crypto_pcbc_alloc(struct rtattr **tb)
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;
......
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