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[CRYPTO] ctr: Use crypto_inc and crypto_xor

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This patch replaces the custom inc/xor in CTR with the generic functions.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Herbert Xu 2007-11-20 20:32:56 +08:00
parent d0b9007a27
commit 3f8214ea33
1 changed files with 16 additions and 55 deletions
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71
crypto/ctr.c
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@ -31,51 +31,6 @@ struct crypto_ctr_ctx {
u8 *nonce;
};
static inline void __ctr_inc_byte(u8 *a, unsigned int size)
{
u8 *b = (a + size);
u8 c;
for (; size; size--) {
c = *--b + 1;
*b = c;
if (c)
break;
}
}
static void ctr_inc_quad(u8 *a, unsigned int size)
{
__be32 *b = (__be32 *)(a + size);
u32 c;
for (; size >= 4; size -=4) {
c = be32_to_cpu(*--b) + 1;
*b = cpu_to_be32(c);
if (c)
return;
}
__ctr_inc_byte(a, size);
}
static void xor_byte(u8 *a, const u8 *b, unsigned int bs)
{
for (; bs; bs--)
*a++ ^= *b++;
}
static void xor_quad(u8 *dst, const u8 *src, unsigned int bs)
{
u32 *a = (u32 *)dst;
u32 *b = (u32 *)src;
for (; bs >= 4; bs -= 4)
*a++ ^= *b++;
xor_byte((u8 *)a, (u8 *)b, bs);
}
static int crypto_ctr_setkey(struct crypto_tfm *parent, const u8 *key,
unsigned int keylen)
{
@ -111,7 +66,8 @@ static int crypto_ctr_crypt_segment(struct blkcipher_walk *walk,
void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
crypto_cipher_alg(tfm)->cia_encrypt;
unsigned int bsize = crypto_cipher_blocksize(tfm);
unsigned long alignmask = crypto_cipher_alignmask(tfm);
unsigned long alignmask = crypto_cipher_alignmask(tfm) |
(__alignof__(u32) - 1);
u8 ks[bsize + alignmask];
u8 *keystream = (u8 *)ALIGN((unsigned long)ks, alignmask + 1);
u8 *src = walk->src.virt.addr;
@ -121,13 +77,13 @@ static int crypto_ctr_crypt_segment(struct blkcipher_walk *walk,
do {
/* create keystream */
fn(crypto_cipher_tfm(tfm), keystream, ctrblk);
xor_quad(keystream, src, min(nbytes, bsize));
crypto_xor(keystream, src, min(nbytes, bsize));
/* copy result into dst */
memcpy(dst, keystream, min(nbytes, bsize));
/* increment counter in counterblock */
ctr_inc_quad(ctrblk + (bsize - countersize), countersize);
crypto_inc(ctrblk + bsize - countersize, countersize);
if (nbytes < bsize)
break;
@ -148,7 +104,8 @@ static int crypto_ctr_crypt_inplace(struct blkcipher_walk *walk,
void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
crypto_cipher_alg(tfm)->cia_encrypt;
unsigned int bsize = crypto_cipher_blocksize(tfm);
unsigned long alignmask = crypto_cipher_alignmask(tfm);
unsigned long alignmask = crypto_cipher_alignmask(tfm) |
(__alignof__(u32) - 1);
unsigned int nbytes = walk->nbytes;
u8 *src = walk->src.virt.addr;
u8 ks[bsize + alignmask];
@ -157,10 +114,10 @@ static int crypto_ctr_crypt_inplace(struct blkcipher_walk *walk,
do {
/* create keystream */
fn(crypto_cipher_tfm(tfm), keystream, ctrblk);
xor_quad(src, keystream, min(nbytes, bsize));
crypto_xor(src, keystream, min(nbytes, bsize));
/* increment counter in counterblock */
ctr_inc_quad(ctrblk + (bsize - countersize), countersize);
crypto_inc(ctrblk + bsize - countersize, countersize);
if (nbytes < bsize)
break;
@ -184,7 +141,8 @@ static int crypto_ctr_crypt(struct blkcipher_desc *desc,
unsigned int bsize = crypto_cipher_blocksize(child);
struct ctr_instance_ctx *ictx =
crypto_instance_ctx(crypto_tfm_alg_instance(&tfm->base));
unsigned long alignmask = crypto_cipher_alignmask(child);
unsigned long alignmask = crypto_cipher_alignmask(child) |
(__alignof__(u32) - 1);
u8 cblk[bsize + alignmask];
u8 *counterblk = (u8 *)ALIGN((unsigned long)cblk, alignmask + 1);
int err;
@ -198,8 +156,7 @@ static int crypto_ctr_crypt(struct blkcipher_desc *desc,
memcpy(counterblk + ictx->noncesize, walk.iv, ictx->ivsize);
/* initialize counter portion of counter block */
ctr_inc_quad(counterblk + (bsize - ictx->countersize),
ictx->countersize);
crypto_inc(counterblk + bsize - ictx->countersize, ictx->countersize);
while (walk.nbytes) {
if (walk.src.virt.addr == walk.dst.virt.addr)
@ -284,6 +241,10 @@ static struct crypto_instance *crypto_ctr_alloc(struct rtattr **tb)
(countersize > alg->cra_blocksize) || (countersize < 4))
goto out_put_alg;
/* If this is false we'd fail the alignment of crypto_inc. */
if ((alg->cra_blocksize - countersize) % 4)
goto out_put_alg;
inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);
err = -ENOMEM;
if (!inst)
@ -316,7 +277,7 @@ static struct crypto_instance *crypto_ctr_alloc(struct rtattr **tb)
inst->alg.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER;
inst->alg.cra_priority = alg->cra_priority;
inst->alg.cra_blocksize = 1;
inst->alg.cra_alignmask = 3;
inst->alg.cra_alignmask = __alignof__(u32) - 1;
inst->alg.cra_type = &crypto_blkcipher_type;
inst->alg.cra_blkcipher.ivsize = ivsize;