[CRYPTO] ctr: Use crypto_inc and crypto_xor

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

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/crypto/ctr.c b/crypto/ctr.c
index b974a9f9b8797e1329b78c57b4e1b42e3e017cb8..b816e959fa550a120e9f2c7add924788225ce5c8 100644 (file)
--- a/crypto/ctr.c
+++ b/crypto/ctr.c
@@ -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;