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