arch/arm64/crypto/sm4-ce-ccm-glue.c - linux - Git at Google

 /* SPDX-License-Identifier: GPL-2.0-or-later */
 /*
  * SM4-CCM AEAD Algorithm using ARMv8 Crypto Extensions
  * as specified in rfc8998
  * https://datatracker.ietf.org/doc/html/rfc8998
  *
  * Copyright (C) 2022 Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
  */

 #include <linux/module.h>
 #include <linux/crypto.h>
 #include <linux/kernel.h>
 #include <linux/cpufeature.h>
 #include <asm/neon.h>
 #include <crypto/scatterwalk.h>
 #include <crypto/internal/aead.h>
 #include <crypto/internal/skcipher.h>
 #include <crypto/sm4.h>
 #include "sm4-ce.h"

 asmlinkage void sm4_ce_cbcmac_update(const u32 *rkey_enc, u8 *mac,
 				     const u8 *src, unsigned int nblocks);
 asmlinkage void sm4_ce_ccm_enc(const u32 *rkey_enc, u8 *dst, const u8 *src,
 			       u8 *iv, unsigned int nbytes, u8 *mac);
 asmlinkage void sm4_ce_ccm_dec(const u32 *rkey_enc, u8 *dst, const u8 *src,
 			       u8 *iv, unsigned int nbytes, u8 *mac);
 asmlinkage void sm4_ce_ccm_final(const u32 *rkey_enc, u8 *iv, u8 *mac);


 static int ccm_setkey(struct crypto_aead *tfm, const u8 *key,
 		      unsigned int key_len)
 {
 	struct sm4_ctx *ctx = crypto_aead_ctx(tfm);

 	if (key_len != SM4_KEY_SIZE)
 		return -EINVAL;

 	kernel_neon_begin();
 	sm4_ce_expand_key(key, ctx->rkey_enc, ctx->rkey_dec,
 			  crypto_sm4_fk, crypto_sm4_ck);
 	kernel_neon_end();

 	return 0;
 }

 static int ccm_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
 {
 	if ((authsize & 1) || authsize < 4)
 		return -EINVAL;
 	return 0;
 }

 static int ccm_format_input(u8 info[], struct aead_request *req,
 			    unsigned int msglen)
 {
 	struct crypto_aead *aead = crypto_aead_reqtfm(req);
 	unsigned int l = req->iv[0] + 1;
 	unsigned int m;
 	__be32 len;

 	/* verify that CCM dimension 'L': 2 <= L <= 8 */
 	if (l < 2 || l > 8)
 		return -EINVAL;
 	if (l < 4 && msglen >> (8 * l))
 		return -EOVERFLOW;

 	memset(&req->iv[SM4_BLOCK_SIZE - l], 0, l);

 	memcpy(info, req->iv, SM4_BLOCK_SIZE);

 	m = crypto_aead_authsize(aead);

 	/* format flags field per RFC 3610/NIST 800-38C */
 	*info |= ((m - 2) / 2) << 3;
 	if (req->assoclen)
 		*info |= (1 << 6);

 	/*
 	 * format message length field,
 	 * Linux uses a u32 type to represent msglen
 	 */
 	if (l >= 4)
 		l = 4;

 	len = cpu_to_be32(msglen);
 	memcpy(&info[SM4_BLOCK_SIZE - l], (u8 *)&len + 4 - l, l);

 	return 0;
 }

 static void ccm_calculate_auth_mac(struct aead_request *req, u8 mac[])
 {
 	struct crypto_aead *aead = crypto_aead_reqtfm(req);
 	struct sm4_ctx *ctx = crypto_aead_ctx(aead);
 	struct __packed { __be16 l; __be32 h; } aadlen;
 	u32 assoclen = req->assoclen;
 	struct scatter_walk walk;
 	unsigned int len;

 	if (assoclen < 0xff00) {
 		aadlen.l = cpu_to_be16(assoclen);
 		len = 2;
 	} else {
 		aadlen.l = cpu_to_be16(0xfffe);
 		put_unaligned_be32(assoclen, &aadlen.h);
 		len = 6;
 	}

 	sm4_ce_crypt_block(ctx->rkey_enc, mac, mac);
 	crypto_xor(mac, (const u8 *)&aadlen, len);

 	scatterwalk_start(&walk, req->src);

 	do {
 		u32 n = scatterwalk_clamp(&walk, assoclen);
 		u8 *p, *ptr;

 		if (!n) {
 			scatterwalk_start(&walk, sg_next(walk.sg));
 			n = scatterwalk_clamp(&walk, assoclen);
 		}

 		p = ptr = scatterwalk_map(&walk);
 		assoclen -= n;
 		scatterwalk_advance(&walk, n);

 		while (n > 0) {
 			unsigned int l, nblocks;

 			if (len == SM4_BLOCK_SIZE) {
 				if (n < SM4_BLOCK_SIZE) {
 					sm4_ce_crypt_block(ctx->rkey_enc,
 							   mac, mac);

 					len = 0;
 				} else {
 					nblocks = n / SM4_BLOCK_SIZE;
 					sm4_ce_cbcmac_update(ctx->rkey_enc,
 							     mac, ptr, nblocks);

 					ptr += nblocks * SM4_BLOCK_SIZE;
 					n %= SM4_BLOCK_SIZE;

 					continue;
 				}
 			}

 			l = min(n, SM4_BLOCK_SIZE - len);
 			if (l) {
 				crypto_xor(mac + len, ptr, l);
 				len += l;
 				ptr += l;
 				n -= l;
 			}
 		}

 		scatterwalk_unmap(p);
 		scatterwalk_done(&walk, 0, assoclen);
 	} while (assoclen);
 }

 static int ccm_crypt(struct aead_request *req, struct skcipher_walk *walk,
 		     u32 *rkey_enc, u8 mac[],
 		     void (*sm4_ce_ccm_crypt)(const u32 *rkey_enc, u8 *dst,
 					const u8 *src, u8 *iv,
 					unsigned int nbytes, u8 *mac))
 {
 	u8 __aligned(8) ctr0[SM4_BLOCK_SIZE];
 	int err;

 	/* preserve the initial ctr0 for the TAG */
 	memcpy(ctr0, walk->iv, SM4_BLOCK_SIZE);
 	crypto_inc(walk->iv, SM4_BLOCK_SIZE);

 	kernel_neon_begin();

 	if (req->assoclen)
 		ccm_calculate_auth_mac(req, mac);

 	do {
 		unsigned int tail = walk->nbytes % SM4_BLOCK_SIZE;
 		const u8 *src = walk->src.virt.addr;
 		u8 *dst = walk->dst.virt.addr;

 		if (walk->nbytes == walk->total)
 			tail = 0;

 		if (walk->nbytes - tail)
 			sm4_ce_ccm_crypt(rkey_enc, dst, src, walk->iv,
 					 walk->nbytes - tail, mac);

 		if (walk->nbytes == walk->total)
 			sm4_ce_ccm_final(rkey_enc, ctr0, mac);

 		kernel_neon_end();

 		if (walk->nbytes) {
 			err = skcipher_walk_done(walk, tail);
 			if (err)
 				return err;
 			if (walk->nbytes)
 				kernel_neon_begin();
 		}
 	} while (walk->nbytes > 0);

 	return 0;
 }

 static int ccm_encrypt(struct aead_request *req)
 {
 	struct crypto_aead *aead = crypto_aead_reqtfm(req);
 	struct sm4_ctx *ctx = crypto_aead_ctx(aead);
 	u8 __aligned(8) mac[SM4_BLOCK_SIZE];
 	struct skcipher_walk walk;
 	int err;

 	err = ccm_format_input(mac, req, req->cryptlen);
 	if (err)
 		return err;

 	err = skcipher_walk_aead_encrypt(&walk, req, false);
 	if (err)
 		return err;

 	err = ccm_crypt(req, &walk, ctx->rkey_enc, mac, sm4_ce_ccm_enc);
 	if (err)
 		return err;

 	/* copy authtag to end of dst */
 	scatterwalk_map_and_copy(mac, req->dst, req->assoclen + req->cryptlen,
 				 crypto_aead_authsize(aead), 1);

 	return 0;
 }

 static int ccm_decrypt(struct aead_request *req)
 {
 	struct crypto_aead *aead = crypto_aead_reqtfm(req);
 	unsigned int authsize = crypto_aead_authsize(aead);
 	struct sm4_ctx *ctx = crypto_aead_ctx(aead);
 	u8 __aligned(8) mac[SM4_BLOCK_SIZE];
 	u8 authtag[SM4_BLOCK_SIZE];
 	struct skcipher_walk walk;
 	int err;

 	err = ccm_format_input(mac, req, req->cryptlen - authsize);
 	if (err)
 		return err;

 	err = skcipher_walk_aead_decrypt(&walk, req, false);
 	if (err)
 		return err;

 	err = ccm_crypt(req, &walk, ctx->rkey_enc, mac, sm4_ce_ccm_dec);
 	if (err)
 		return err;

 	/* compare calculated auth tag with the stored one */
 	scatterwalk_map_and_copy(authtag, req->src,
 				 req->assoclen + req->cryptlen - authsize,
 				 authsize, 0);

 	if (crypto_memneq(authtag, mac, authsize))
 		return -EBADMSG;

 	return 0;
 }

 static struct aead_alg sm4_ccm_alg = {
 	.base = {
 		.cra_name		= "ccm(sm4)",
 		.cra_driver_name	= "ccm-sm4-ce",
 		.cra_priority		= 400,
 		.cra_blocksize		= 1,
 		.cra_ctxsize		= sizeof(struct sm4_ctx),
 		.cra_module		= THIS_MODULE,
 	},
 	.ivsize		= SM4_BLOCK_SIZE,
 	.chunksize	= SM4_BLOCK_SIZE,
 	.maxauthsize	= SM4_BLOCK_SIZE,
 	.setkey		= ccm_setkey,
 	.setauthsize	= ccm_setauthsize,
 	.encrypt	= ccm_encrypt,
 	.decrypt	= ccm_decrypt,
 };

 static int __init sm4_ce_ccm_init(void)
 {
 	return crypto_register_aead(&sm4_ccm_alg);
 }

 static void __exit sm4_ce_ccm_exit(void)
 {
 	crypto_unregister_aead(&sm4_ccm_alg);
 }

 module_cpu_feature_match(SM4, sm4_ce_ccm_init);
 module_exit(sm4_ce_ccm_exit);

 MODULE_DESCRIPTION("Synchronous SM4 in CCM mode using ARMv8 Crypto Extensions");
 MODULE_ALIAS_CRYPTO("ccm(sm4)");
 MODULE_AUTHOR("Tianjia Zhang <tianjia.zhang@linux.alibaba.com>");
 MODULE_LICENSE("GPL v2");
	/* SPDX-License-Identifier: GPL-2.0-or-later */
	/*
	* SM4-CCM AEAD Algorithm using ARMv8 Crypto Extensions
	* as specified in rfc8998
	* https://datatracker.ietf.org/doc/html/rfc8998
	*
	* Copyright (C) 2022 Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
	*/

	#include <linux/module.h>
	#include <linux/crypto.h>
	#include <linux/kernel.h>
	#include <linux/cpufeature.h>
	#include <asm/neon.h>
	#include <crypto/scatterwalk.h>
	#include <crypto/internal/aead.h>
	#include <crypto/internal/skcipher.h>
	#include <crypto/sm4.h>
	#include "sm4-ce.h"

	asmlinkage void sm4_ce_cbcmac_update(const u32 rkey_enc, u8 mac,
	const u8 *src, unsigned int nblocks);
	asmlinkage void sm4_ce_ccm_enc(const u32 rkey_enc, u8 dst, const u8 *src,
	u8 iv, unsigned int nbytes, u8 mac);
	asmlinkage void sm4_ce_ccm_dec(const u32 rkey_enc, u8 dst, const u8 *src,
	u8 iv, unsigned int nbytes, u8 mac);
	asmlinkage void sm4_ce_ccm_final(const u32 rkey_enc, u8 iv, u8 *mac);


	static int ccm_setkey(struct crypto_aead tfm, const u8 key,
	unsigned int key_len)
	{
	struct sm4_ctx *ctx = crypto_aead_ctx(tfm);

	if (key_len != SM4_KEY_SIZE)
	return -EINVAL;

	kernel_neon_begin();
	sm4_ce_expand_key(key, ctx->rkey_enc, ctx->rkey_dec,
	crypto_sm4_fk, crypto_sm4_ck);
	kernel_neon_end();

	return 0;
	}

	static int ccm_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
	{
	if ((authsize & 1) \|\| authsize < 4)
	return -EINVAL;
	return 0;
	}

	static int ccm_format_input(u8 info[], struct aead_request *req,
	unsigned int msglen)
	{
	struct crypto_aead *aead = crypto_aead_reqtfm(req);
	unsigned int l = req->iv[0] + 1;
	unsigned int m;
	__be32 len;

	/* verify that CCM dimension 'L': 2 <= L <= 8 */
	if (l < 2 \|\| l > 8)
	return -EINVAL;
	if (l < 4 && msglen >> (8 * l))
	return -EOVERFLOW;

	memset(&req->iv[SM4_BLOCK_SIZE - l], 0, l);

	memcpy(info, req->iv, SM4_BLOCK_SIZE);

	m = crypto_aead_authsize(aead);

	/* format flags field per RFC 3610/NIST 800-38C */
	*info \|= ((m - 2) / 2) << 3;
	if (req->assoclen)
	*info \|= (1 << 6);

	/*
	* format message length field,
	* Linux uses a u32 type to represent msglen
	*/
	if (l >= 4)
	l = 4;

	len = cpu_to_be32(msglen);
	memcpy(&info[SM4_BLOCK_SIZE - l], (u8 *)&len + 4 - l, l);

	return 0;
	}

	static void ccm_calculate_auth_mac(struct aead_request *req, u8 mac[])
	{
	struct crypto_aead *aead = crypto_aead_reqtfm(req);
	struct sm4_ctx *ctx = crypto_aead_ctx(aead);
	struct __packed { __be16 l; __be32 h; } aadlen;
	u32 assoclen = req->assoclen;
	struct scatter_walk walk;
	unsigned int len;

	if (assoclen < 0xff00) {
	aadlen.l = cpu_to_be16(assoclen);
	len = 2;
	} else {
	aadlen.l = cpu_to_be16(0xfffe);
	put_unaligned_be32(assoclen, &aadlen.h);
	len = 6;
	}

	sm4_ce_crypt_block(ctx->rkey_enc, mac, mac);
	crypto_xor(mac, (const u8 *)&aadlen, len);

	scatterwalk_start(&walk, req->src);

	do {
	u32 n = scatterwalk_clamp(&walk, assoclen);
	u8 p, ptr;

	if (!n) {
	scatterwalk_start(&walk, sg_next(walk.sg));
	n = scatterwalk_clamp(&walk, assoclen);
	}

	p = ptr = scatterwalk_map(&walk);
	assoclen -= n;
	scatterwalk_advance(&walk, n);

	while (n > 0) {
	unsigned int l, nblocks;

	if (len == SM4_BLOCK_SIZE) {
	if (n < SM4_BLOCK_SIZE) {
	sm4_ce_crypt_block(ctx->rkey_enc,
	mac, mac);

	len = 0;
	} else {
	nblocks = n / SM4_BLOCK_SIZE;
	sm4_ce_cbcmac_update(ctx->rkey_enc,
	mac, ptr, nblocks);

	ptr += nblocks * SM4_BLOCK_SIZE;
	n %= SM4_BLOCK_SIZE;

	continue;
	}
	}

	l = min(n, SM4_BLOCK_SIZE - len);
	if (l) {
	crypto_xor(mac + len, ptr, l);
	len += l;
	ptr += l;
	n -= l;
	}
	}

	scatterwalk_unmap(p);
	scatterwalk_done(&walk, 0, assoclen);
	} while (assoclen);
	}

	static int ccm_crypt(struct aead_request req, struct skcipher_walk walk,
	u32 *rkey_enc, u8 mac[],
	void (sm4_ce_ccm_crypt)(const u32 rkey_enc, u8 *dst,
	const u8 src, u8 iv,
	unsigned int nbytes, u8 *mac))
	{
	u8 __aligned(8) ctr0[SM4_BLOCK_SIZE];
	int err;

	/* preserve the initial ctr0 for the TAG */
	memcpy(ctr0, walk->iv, SM4_BLOCK_SIZE);
	crypto_inc(walk->iv, SM4_BLOCK_SIZE);

	kernel_neon_begin();

	if (req->assoclen)
	ccm_calculate_auth_mac(req, mac);

	do {
	unsigned int tail = walk->nbytes % SM4_BLOCK_SIZE;
	const u8 *src = walk->src.virt.addr;
	u8 *dst = walk->dst.virt.addr;

	if (walk->nbytes == walk->total)
	tail = 0;

	if (walk->nbytes - tail)
	sm4_ce_ccm_crypt(rkey_enc, dst, src, walk->iv,
	walk->nbytes - tail, mac);

	if (walk->nbytes == walk->total)
	sm4_ce_ccm_final(rkey_enc, ctr0, mac);

	kernel_neon_end();

	if (walk->nbytes) {
	err = skcipher_walk_done(walk, tail);
	if (err)
	return err;
	if (walk->nbytes)
	kernel_neon_begin();
	}
	} while (walk->nbytes > 0);

	return 0;
	}

	static int ccm_encrypt(struct aead_request *req)
	{
	struct crypto_aead *aead = crypto_aead_reqtfm(req);
	struct sm4_ctx *ctx = crypto_aead_ctx(aead);
	u8 __aligned(8) mac[SM4_BLOCK_SIZE];
	struct skcipher_walk walk;
	int err;

	err = ccm_format_input(mac, req, req->cryptlen);
	if (err)
	return err;

	err = skcipher_walk_aead_encrypt(&walk, req, false);
	if (err)
	return err;

	err = ccm_crypt(req, &walk, ctx->rkey_enc, mac, sm4_ce_ccm_enc);
	if (err)
	return err;

	/* copy authtag to end of dst */
	scatterwalk_map_and_copy(mac, req->dst, req->assoclen + req->cryptlen,
	crypto_aead_authsize(aead), 1);

	return 0;
	}

	static int ccm_decrypt(struct aead_request *req)
	{
	struct crypto_aead *aead = crypto_aead_reqtfm(req);
	unsigned int authsize = crypto_aead_authsize(aead);
	struct sm4_ctx *ctx = crypto_aead_ctx(aead);
	u8 __aligned(8) mac[SM4_BLOCK_SIZE];
	u8 authtag[SM4_BLOCK_SIZE];
	struct skcipher_walk walk;
	int err;

	err = ccm_format_input(mac, req, req->cryptlen - authsize);
	if (err)
	return err;

	err = skcipher_walk_aead_decrypt(&walk, req, false);
	if (err)
	return err;

	err = ccm_crypt(req, &walk, ctx->rkey_enc, mac, sm4_ce_ccm_dec);
	if (err)
	return err;

	/* compare calculated auth tag with the stored one */
	scatterwalk_map_and_copy(authtag, req->src,
	req->assoclen + req->cryptlen - authsize,
	authsize, 0);

	if (crypto_memneq(authtag, mac, authsize))
	return -EBADMSG;

	return 0;
	}

	static struct aead_alg sm4_ccm_alg = {
	.base = {
	.cra_name = "ccm(sm4)",
	.cra_driver_name = "ccm-sm4-ce",
	.cra_priority = 400,
	.cra_blocksize = 1,
	.cra_ctxsize = sizeof(struct sm4_ctx),
	.cra_module = THIS_MODULE,
	},
	.ivsize = SM4_BLOCK_SIZE,
	.chunksize = SM4_BLOCK_SIZE,
	.maxauthsize = SM4_BLOCK_SIZE,
	.setkey = ccm_setkey,
	.setauthsize = ccm_setauthsize,
	.encrypt = ccm_encrypt,
	.decrypt = ccm_decrypt,
	};

	static int __init sm4_ce_ccm_init(void)
	{
	return crypto_register_aead(&sm4_ccm_alg);
	}

	static void __exit sm4_ce_ccm_exit(void)
	{
	crypto_unregister_aead(&sm4_ccm_alg);
	}

	module_cpu_feature_match(SM4, sm4_ce_ccm_init);
	module_exit(sm4_ce_ccm_exit);

	MODULE_DESCRIPTION("Synchronous SM4 in CCM mode using ARMv8 Crypto Extensions");
	MODULE_ALIAS_CRYPTO("ccm(sm4)");
	MODULE_AUTHOR("Tianjia Zhang <tianjia.zhang@linux.alibaba.com>");
	MODULE_LICENSE("GPL v2");