Commit f4bb3136 authored by Herbert Xu's avatar Herbert Xu
Browse files

crypto: cmac - Use API partial block handling 



Use the Crypto API partial block handling.

Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent ca5d7d5f

crypto/cmac.c

+18 −74
Original line number Diff line number Diff line
@@ -13,9 +13,12 @@ 


#include <crypto/internal/cipher.h>

#include <crypto/internal/hash.h>

#include <crypto/utils.h>

#include <linux/err.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/slab.h>

#include <linux/string.h>



/*

 * +------------------------
@@ -31,22 +34,6 @@ struct cmac_tfm_ctx { 
	__be64 consts[];

};



/*

 * +------------------------

 * | <shash desc>

 * +------------------------

 * | cmac_desc_ctx

 * +------------------------

 * | odds (block size)

 * +------------------------

 * | prev (block size)

 * +------------------------

 */

struct cmac_desc_ctx {

	unsigned int len;

	u8 odds[];

};



static int crypto_cmac_digest_setkey(struct crypto_shash *parent,

				     const u8 *inkey, unsigned int keylen)

{
@@ -102,13 +89,10 @@ static int crypto_cmac_digest_setkey(struct crypto_shash *parent, 


static int crypto_cmac_digest_init(struct shash_desc *pdesc)

{

	struct cmac_desc_ctx *ctx = shash_desc_ctx(pdesc);

	int bs = crypto_shash_blocksize(pdesc->tfm);

	u8 *prev = &ctx->odds[bs];

	u8 *prev = shash_desc_ctx(pdesc);



	ctx->len = 0;

	memset(prev, 0, bs);



	return 0;

}
@@ -117,77 +101,36 @@ static int crypto_cmac_digest_update(struct shash_desc *pdesc, const u8 *p, 
{

	struct crypto_shash *parent = pdesc->tfm;

	struct cmac_tfm_ctx *tctx = crypto_shash_ctx(parent);

	struct cmac_desc_ctx *ctx = shash_desc_ctx(pdesc);

	struct crypto_cipher *tfm = tctx->child;

	int bs = crypto_shash_blocksize(parent);

	u8 *odds = ctx->odds;

	u8 *prev = odds + bs;

	u8 *prev = shash_desc_ctx(pdesc);



	/* checking the data can fill the block */

	if ((ctx->len + len) <= bs) {

		memcpy(odds + ctx->len, p, len);

		ctx->len += len;

		return 0;

	}



	/* filling odds with new data and encrypting it */

	memcpy(odds + ctx->len, p, bs - ctx->len);

	len -= bs - ctx->len;

	p += bs - ctx->len;



	crypto_xor(prev, odds, bs);

	crypto_cipher_encrypt_one(tfm, prev, prev);



	/* clearing the length */

	ctx->len = 0;



	/* encrypting the rest of data */

	while (len > bs) {

	do {

		crypto_xor(prev, p, bs);

		crypto_cipher_encrypt_one(tfm, prev, prev);

		p += bs;

		len -= bs;

	} while (len >= bs);

	return len;

}



	/* keeping the surplus of blocksize */

	if (len) {

		memcpy(odds, p, len);

		ctx->len = len;

	}



	return 0;

}



static int crypto_cmac_digest_final(struct shash_desc *pdesc, u8 *out)

static int crypto_cmac_digest_finup(struct shash_desc *pdesc, const u8 *src,

				    unsigned int len, u8 *out)

{

	struct crypto_shash *parent = pdesc->tfm;

	struct cmac_tfm_ctx *tctx = crypto_shash_ctx(parent);

	struct cmac_desc_ctx *ctx = shash_desc_ctx(pdesc);

	struct crypto_cipher *tfm = tctx->child;

	int bs = crypto_shash_blocksize(parent);

	u8 *odds = ctx->odds;

	u8 *prev = odds + bs;

	u8 *prev = shash_desc_ctx(pdesc);

	unsigned int offset = 0;



	if (ctx->len != bs) {

		unsigned int rlen;

		u8 *p = odds + ctx->len;



		*p = 0x80;

		p++;



		rlen = bs - ctx->len - 1;

		if (rlen)

			memset(p, 0, rlen);



	crypto_xor(prev, src, len);

	if (len != bs) {

		prev[len] ^= 0x80;

		offset += bs;

	}



	crypto_xor(prev, odds, bs);

	crypto_xor(prev, (const u8 *)tctx->consts + offset, bs);



	crypto_cipher_encrypt_one(tfm, out, prev);



	return 0;

}
@@ -269,13 +212,14 @@ static int cmac_create(struct crypto_template *tmpl, struct rtattr **tb) 
	inst->alg.base.cra_blocksize = alg->cra_blocksize;

	inst->alg.base.cra_ctxsize = sizeof(struct cmac_tfm_ctx) +

				     alg->cra_blocksize * 2;

	inst->alg.base.cra_flags = CRYPTO_AHASH_ALG_BLOCK_ONLY |

				   CRYPTO_AHASH_ALG_FINAL_NONZERO;



	inst->alg.digestsize = alg->cra_blocksize;

	inst->alg.descsize = sizeof(struct cmac_desc_ctx) +

			     alg->cra_blocksize * 2;

	inst->alg.descsize = alg->cra_blocksize;

	inst->alg.init = crypto_cmac_digest_init;

	inst->alg.update = crypto_cmac_digest_update;

	inst->alg.final = crypto_cmac_digest_final;

	inst->alg.finup = crypto_cmac_digest_finup;

	inst->alg.setkey = crypto_cmac_digest_setkey;

	inst->alg.init_tfm = cmac_init_tfm;

	inst->alg.clone_tfm = cmac_clone_tfm;