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Commit 93b5e86a authored by Jussi Kivilinna's avatar Jussi Kivilinna Committed by Herbert Xu
Browse files

crypto: add CMAC support to CryptoAPI 

Patch adds support for NIST recommended block cipher mode CMAC to CryptoAPI.

This work is based on Tom St Denis' earlier patch,
 http://marc.info/?l=linux-crypto-vger&m=135877306305466&w=2



Cc: Tom St Denis <tstdenis@elliptictech.com>
Signed-off-by: default avatarJussi Kivilinna <jussi.kivilinna@iki.fi>
Acked-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent e448370d

crypto/Kconfig

+11 −0
Original line number Diff line number Diff line
@@ -283,6 +283,17 @@ config CRYPTO_XTS 


comment "Hash modes"



config CRYPTO_CMAC

	tristate "CMAC support"

	select CRYPTO_HASH

	select CRYPTO_MANAGER

	help

	  Cipher-based Message Authentication Code (CMAC) specified by

	  The National Institute of Standards and Technology (NIST).



	  https://tools.ietf.org/html/rfc4493

	  http://csrc.nist.gov/publications/nistpubs/800-38B/SP_800-38B.pdf



config CRYPTO_HMAC

	tristate "HMAC support"

	select CRYPTO_HASH

crypto/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -32,6 +32,7 @@ cryptomgr-y := algboss.o testmgr.o 


obj-$(CONFIG_CRYPTO_MANAGER2) += cryptomgr.o

obj-$(CONFIG_CRYPTO_USER) += crypto_user.o

obj-$(CONFIG_CRYPTO_CMAC) += cmac.o

obj-$(CONFIG_CRYPTO_HMAC) += hmac.o

obj-$(CONFIG_CRYPTO_VMAC) += vmac.o

obj-$(CONFIG_CRYPTO_XCBC) += xcbc.o

crypto/cmac.c

0 → 100644
+315 −0
Original line number Diff line number Diff line 
/*

 * CMAC: Cipher Block Mode for Authentication

 *

 * Copyright © 2013 Jussi Kivilinna <jussi.kivilinna@iki.fi>

 *

 * Based on work by:

 *  Copyright © 2013 Tom St Denis <tstdenis@elliptictech.com>

 * Based on crypto/xcbc.c:

 *  Copyright © 2006 USAGI/WIDE Project,

 *   Author: Kazunori Miyazawa <miyazawa@linux-ipv6.org>

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 */



#include <crypto/internal/hash.h>

#include <linux/err.h>

#include <linux/kernel.h>

#include <linux/module.h>



/*

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

 * | <parent tfm>

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

 * | cmac_tfm_ctx

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

 * | consts (block size * 2)

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

 */

struct cmac_tfm_ctx {

	struct crypto_cipher *child;

	u8 ctx[];

};



/*

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

 * | <shash desc>

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

 * | cmac_desc_ctx

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

 * | odds (block size)

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

 * | prev (block size)

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

 */

struct cmac_desc_ctx {

	unsigned int len;

	u8 ctx[];

};



static int crypto_cmac_digest_setkey(struct crypto_shash *parent,

				     const u8 *inkey, unsigned int keylen)

{

	unsigned long alignmask = crypto_shash_alignmask(parent);

	struct cmac_tfm_ctx *ctx = crypto_shash_ctx(parent);

	unsigned int bs = crypto_shash_blocksize(parent);

	__be64 *consts = PTR_ALIGN((void *)ctx->ctx, alignmask + 1);

	u64 _const[2];

	int i, err = 0;

	u8 msb_mask, gfmask;



	err = crypto_cipher_setkey(ctx->child, inkey, keylen);

	if (err)

		return err;



	/* encrypt the zero block */

	memset(consts, 0, bs);

	crypto_cipher_encrypt_one(ctx->child, (u8 *)consts, (u8 *)consts);



	switch (bs) {

	case 16:

		gfmask = 0x87;

		_const[0] = be64_to_cpu(consts[1]);

		_const[1] = be64_to_cpu(consts[0]);



		/* gf(2^128) multiply zero-ciphertext with u and u^2 */

		for (i = 0; i < 4; i += 2) {

			msb_mask = ((s64)_const[1] >> 63) & gfmask;

			_const[1] = (_const[1] << 1) | (_const[0] >> 63);

			_const[0] = (_const[0] << 1) ^ msb_mask;



			consts[i + 0] = cpu_to_be64(_const[1]);

			consts[i + 1] = cpu_to_be64(_const[0]);

		}



		break;

	case 8:

		gfmask = 0x1B;

		_const[0] = be64_to_cpu(consts[0]);



		/* gf(2^64) multiply zero-ciphertext with u and u^2 */

		for (i = 0; i < 2; i++) {

			msb_mask = ((s64)_const[0] >> 63) & gfmask;

			_const[0] = (_const[0] << 1) ^ msb_mask;



			consts[i] = cpu_to_be64(_const[0]);

		}



		break;

	}



	return 0;

}



static int crypto_cmac_digest_init(struct shash_desc *pdesc)

{

	unsigned long alignmask = crypto_shash_alignmask(pdesc->tfm);

	struct cmac_desc_ctx *ctx = shash_desc_ctx(pdesc);

	int bs = crypto_shash_blocksize(pdesc->tfm);

	u8 *prev = PTR_ALIGN((void *)ctx->ctx, alignmask + 1) + bs;



	ctx->len = 0;

	memset(prev, 0, bs);



	return 0;

}



static int crypto_cmac_digest_update(struct shash_desc *pdesc, const u8 *p,

				     unsigned int len)

{

	struct crypto_shash *parent = pdesc->tfm;

	unsigned long alignmask = crypto_shash_alignmask(parent);

	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 = PTR_ALIGN((void *)ctx->ctx, alignmask + 1);

	u8 *prev = odds + bs;



	/* 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) {

		crypto_xor(prev, p, bs);

		crypto_cipher_encrypt_one(tfm, prev, prev);

		p += bs;

		len -= bs;

	}



	/* 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)

{

	struct crypto_shash *parent = pdesc->tfm;

	unsigned long alignmask = crypto_shash_alignmask(parent);

	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 *consts = PTR_ALIGN((void *)tctx->ctx, alignmask + 1);

	u8 *odds = PTR_ALIGN((void *)ctx->ctx, alignmask + 1);

	u8 *prev = odds + bs;

	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);



		offset += bs;

	}



	crypto_xor(prev, odds, bs);

	crypto_xor(prev, consts + offset, bs);



	crypto_cipher_encrypt_one(tfm, out, prev);



	return 0;

}



static int cmac_init_tfm(struct crypto_tfm *tfm)

{

	struct crypto_cipher *cipher;

	struct crypto_instance *inst = (void *)tfm->__crt_alg;

	struct crypto_spawn *spawn = crypto_instance_ctx(inst);

	struct cmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);



	cipher = crypto_spawn_cipher(spawn);

	if (IS_ERR(cipher))

		return PTR_ERR(cipher);



	ctx->child = cipher;



	return 0;

};



static void cmac_exit_tfm(struct crypto_tfm *tfm)

{

	struct cmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);

	crypto_free_cipher(ctx->child);

}



static int cmac_create(struct crypto_template *tmpl, struct rtattr **tb)

{

	struct shash_instance *inst;

	struct crypto_alg *alg;

	unsigned long alignmask;

	int err;



	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH);

	if (err)

		return err;



	alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER,

				  CRYPTO_ALG_TYPE_MASK);

	if (IS_ERR(alg))

		return PTR_ERR(alg);



	switch (alg->cra_blocksize) {

	case 16:

	case 8:

		break;

	default:

		goto out_put_alg;

	}



	inst = shash_alloc_instance("cmac", alg);

	err = PTR_ERR(inst);

	if (IS_ERR(inst))

		goto out_put_alg;



	err = crypto_init_spawn(shash_instance_ctx(inst), alg,

				shash_crypto_instance(inst),

				CRYPTO_ALG_TYPE_MASK);

	if (err)

		goto out_free_inst;



	alignmask = alg->cra_alignmask | (sizeof(long) - 1);

	inst->alg.base.cra_alignmask = alignmask;

	inst->alg.base.cra_priority = alg->cra_priority;

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



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

	inst->alg.descsize =

		ALIGN(sizeof(struct cmac_desc_ctx), crypto_tfm_ctx_alignment())

		+ (alignmask & ~(crypto_tfm_ctx_alignment() - 1))

		+ alg->cra_blocksize * 2;



	inst->alg.base.cra_ctxsize =

		ALIGN(sizeof(struct cmac_tfm_ctx), alignmask + 1)

		+ alg->cra_blocksize * 2;



	inst->alg.base.cra_init = cmac_init_tfm;

	inst->alg.base.cra_exit = cmac_exit_tfm;



	inst->alg.init = crypto_cmac_digest_init;

	inst->alg.update = crypto_cmac_digest_update;

	inst->alg.final = crypto_cmac_digest_final;

	inst->alg.setkey = crypto_cmac_digest_setkey;



	err = shash_register_instance(tmpl, inst);

	if (err) {

out_free_inst:

		shash_free_instance(shash_crypto_instance(inst));

	}



out_put_alg:

	crypto_mod_put(alg);

	return err;

}



static struct crypto_template crypto_cmac_tmpl = {

	.name = "cmac",

	.create = cmac_create,

	.free = shash_free_instance,

	.module = THIS_MODULE,

};



static int __init crypto_cmac_module_init(void)

{

	return crypto_register_template(&crypto_cmac_tmpl);

}



static void __exit crypto_cmac_module_exit(void)

{

	crypto_unregister_template(&crypto_cmac_tmpl);

}



module_init(crypto_cmac_module_init);

module_exit(crypto_cmac_module_exit);



MODULE_LICENSE("GPL");

MODULE_DESCRIPTION("CMAC keyed hash algorithm");

crypto/tcrypt.c

+10 −1
Original line number Diff line number Diff line
@@ -1095,7 +1095,6 @@ static int do_test(int m) 
		break;



	case 28:



		ret += tcrypt_test("tgr160");

		break;
@@ -1118,6 +1117,7 @@ static int do_test(int m) 
		ret += tcrypt_test("lrw(camellia)");

		ret += tcrypt_test("xts(camellia)");

		break;



	case 33:

		ret += tcrypt_test("sha224");

		break;
@@ -1213,6 +1213,7 @@ static int do_test(int m) 
	case 109:

		ret += tcrypt_test("vmac(aes)");

		break;



	case 110:

		ret += tcrypt_test("hmac(crc32)");

		break;
@@ -1229,6 +1230,14 @@ static int do_test(int m) 
		ret += tcrypt_test("rfc4543(gcm(aes))");

		break;



	case 153:

		ret += tcrypt_test("cmac(aes)");

		break;



	case 154:

		ret += tcrypt_test("cmac(des3_ede)");

		break;



	case 200:

		test_cipher_speed("ecb(aes)", ENCRYPT, sec, NULL, 0,

				speed_template_16_24_32);

crypto/testmgr.c

+18 −0
Original line number Diff line number Diff line
@@ -1912,6 +1912,24 @@ static const struct alg_test_desc alg_test_descs[] = { 
				}

			}

		}

	}, {

		.alg = "cmac(aes)",

		.test = alg_test_hash,

		.suite = {

			.hash = {

				.vecs = aes_cmac128_tv_template,

				.count = CMAC_AES_TEST_VECTORS

			}

		}

	}, {

		.alg = "cmac(des3_ede)",

		.test = alg_test_hash,

		.suite = {

			.hash = {

				.vecs = des3_ede_cmac64_tv_template,

				.count = CMAC_DES3_EDE_TEST_VECTORS

			}

		}

	}, {

		.alg = "compress_null",

		.test = alg_test_null,