drivers/crypto/ccp/ccp-crypto-sha.c - arm/linux-arm64-legacy - Git at Google

 /*
  * AMD Cryptographic Coprocessor (CCP) SHA crypto API support
  *
  * Copyright (C) 2013 Advanced Micro Devices, Inc.
  *
  * Author: Tom Lendacky <thomas.lendacky@amd.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  */

 #include <linux/module.h>
 #include <linux/sched.h>
 #include <linux/delay.h>
 #include <linux/scatterlist.h>
 #include <linux/crypto.h>
 #include <crypto/algapi.h>
 #include <crypto/hash.h>
 #include <crypto/internal/hash.h>
 #include <crypto/sha.h>
 #include <crypto/scatterwalk.h>

 #include "ccp-crypto.h"


 static int ccp_sha_complete(struct crypto_async_request *async_req, int ret)
 {
 	struct ahash_request *req = ahash_request_cast(async_req);
 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 	struct ccp_sha_req_ctx *rctx = ahash_request_ctx(req);
 	unsigned int digest_size = crypto_ahash_digestsize(tfm);

 	if (ret)
 		goto e_free;

 	if (rctx->hash_rem) {
 		/* Save remaining data to buffer */
 		unsigned int offset = rctx->nbytes - rctx->hash_rem;
 		scatterwalk_map_and_copy(rctx->buf, rctx->src,
 					 offset, rctx->hash_rem, 0);
 		rctx->buf_count = rctx->hash_rem;
 	} else
 		rctx->buf_count = 0;

 	/* Update result area if supplied */
 	if (req->result)
 		memcpy(req->result, rctx->ctx, digest_size);

 e_free:
 	sg_free_table(&rctx->data_sg);

 	return ret;
 }

 static int ccp_do_sha_update(struct ahash_request *req, unsigned int nbytes,
 			     unsigned int final)
 {
 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 	struct ccp_ctx *ctx = crypto_ahash_ctx(tfm);
 	struct ccp_sha_req_ctx *rctx = ahash_request_ctx(req);
 	struct scatterlist *sg;
 	unsigned int block_size =
 		crypto_tfm_alg_blocksize(crypto_ahash_tfm(tfm));
 	unsigned int sg_count;
 	gfp_t gfp;
 	u64 len;
 	int ret;

 	len = (u64)rctx->buf_count + (u64)nbytes;

 	if (!final && (len <= block_size)) {
 		scatterwalk_map_and_copy(rctx->buf + rctx->buf_count, req->src,
 					 0, nbytes, 0);
 		rctx->buf_count += nbytes;

 		return 0;
 	}

 	rctx->src = req->src;
 	rctx->nbytes = nbytes;

 	rctx->final = final;
 	rctx->hash_rem = final ? 0 : len & (block_size - 1);
 	rctx->hash_cnt = len - rctx->hash_rem;
 	if (!final && !rctx->hash_rem) {
 		/* CCP can't do zero length final, so keep some data around */
 		rctx->hash_cnt -= block_size;
 		rctx->hash_rem = block_size;
 	}

 	/* Initialize the context scatterlist */
 	sg_init_one(&rctx->ctx_sg, rctx->ctx, sizeof(rctx->ctx));

 	sg = NULL;
 	if (rctx->buf_count && nbytes) {
 		/* Build the data scatterlist table - allocate enough entries
 		 * for both data pieces (buffer and input data)
 		 */
 		gfp = req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ?
 			GFP_KERNEL : GFP_ATOMIC;
 		sg_count = sg_nents(req->src) + 1;
 		ret = sg_alloc_table(&rctx->data_sg, sg_count, gfp);
 		if (ret)
 			return ret;

 		sg_init_one(&rctx->buf_sg, rctx->buf, rctx->buf_count);
 		sg = ccp_crypto_sg_table_add(&rctx->data_sg, &rctx->buf_sg);
 		sg = ccp_crypto_sg_table_add(&rctx->data_sg, req->src);
 		sg_mark_end(sg);

 		sg = rctx->data_sg.sgl;
 	} else if (rctx->buf_count) {
 		sg_init_one(&rctx->buf_sg, rctx->buf, rctx->buf_count);

 		sg = &rctx->buf_sg;
 	} else if (nbytes) {
 		sg = req->src;
 	}

 	rctx->msg_bits += (rctx->hash_cnt << 3);	/* Total in bits */

 	memset(&rctx->cmd, 0, sizeof(rctx->cmd));
 	INIT_LIST_HEAD(&rctx->cmd.entry);
 	rctx->cmd.engine = CCP_ENGINE_SHA;
 	rctx->cmd.u.sha.type = rctx->type;
 	rctx->cmd.u.sha.ctx = &rctx->ctx_sg;
 	rctx->cmd.u.sha.ctx_len = sizeof(rctx->ctx);
 	rctx->cmd.u.sha.src = sg;
 	rctx->cmd.u.sha.src_len = rctx->hash_cnt;
 	rctx->cmd.u.sha.opad = ctx->u.sha.key_len ?
 		&ctx->u.sha.opad_sg : NULL;
 	rctx->cmd.u.sha.opad_len = ctx->u.sha.key_len ?
 		ctx->u.sha.opad_count : 0;
 	rctx->cmd.u.sha.first = rctx->first;
 	rctx->cmd.u.sha.final = rctx->final;
 	rctx->cmd.u.sha.msg_bits = rctx->msg_bits;

 	rctx->first = 0;

 	ret = ccp_crypto_enqueue_request(&req->base, &rctx->cmd);

 	return ret;
 }

 static int ccp_sha_init(struct ahash_request *req)
 {
 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
 	struct ccp_ctx *ctx = crypto_ahash_ctx(tfm);
 	struct ccp_sha_req_ctx *rctx = ahash_request_ctx(req);
 	struct ccp_crypto_ahash_alg *alg =
 		ccp_crypto_ahash_alg(crypto_ahash_tfm(tfm));
 	unsigned int block_size =
 		crypto_tfm_alg_blocksize(crypto_ahash_tfm(tfm));

 	memset(rctx, 0, sizeof(*rctx));

 	rctx->type = alg->type;
 	rctx->first = 1;

 	if (ctx->u.sha.key_len) {
 		/* Buffer the HMAC key for first update */
 		memcpy(rctx->buf, ctx->u.sha.ipad, block_size);
 		rctx->buf_count = block_size;
 	}

 	return 0;
 }

 static int ccp_sha_update(struct ahash_request *req)
 {
 	return ccp_do_sha_update(req, req->nbytes, 0);
 }

 static int ccp_sha_final(struct ahash_request *req)
 {
 	return ccp_do_sha_update(req, 0, 1);
 }

 static int ccp_sha_finup(struct ahash_request *req)
 {
 	return ccp_do_sha_update(req, req->nbytes, 1);
 }

 static int ccp_sha_digest(struct ahash_request *req)
 {
 	int ret;

 	ret = ccp_sha_init(req);
 	if (ret)
 		return ret;

 	return ccp_sha_finup(req);
 }

 static int ccp_sha_setkey(struct crypto_ahash *tfm, const u8 *key,
 			  unsigned int key_len)
 {
 	struct ccp_ctx *ctx = crypto_tfm_ctx(crypto_ahash_tfm(tfm));
 	struct crypto_shash *shash = ctx->u.sha.hmac_tfm;
 	struct {
 		struct shash_desc sdesc;
 		char ctx[crypto_shash_descsize(shash)];
 	} desc;
 	unsigned int block_size = crypto_shash_blocksize(shash);
 	unsigned int digest_size = crypto_shash_digestsize(shash);
 	int i, ret;

 	/* Set to zero until complete */
 	ctx->u.sha.key_len = 0;

 	/* Clear key area to provide zero padding for keys smaller
 	 * than the block size
 	 */
 	memset(ctx->u.sha.key, 0, sizeof(ctx->u.sha.key));

 	if (key_len > block_size) {
 		/* Must hash the input key */
 		desc.sdesc.tfm = shash;
 		desc.sdesc.flags = crypto_ahash_get_flags(tfm) &
 			CRYPTO_TFM_REQ_MAY_SLEEP;

 		ret = crypto_shash_digest(&desc.sdesc, key, key_len,
 					  ctx->u.sha.key);
 		if (ret) {
 			crypto_ahash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
 			return -EINVAL;
 		}

 		key_len = digest_size;
 	} else
 		memcpy(ctx->u.sha.key, key, key_len);

 	for (i = 0; i < block_size; i++) {
 		ctx->u.sha.ipad[i] = ctx->u.sha.key[i] ^ 0x36;
 		ctx->u.sha.opad[i] = ctx->u.sha.key[i] ^ 0x5c;
 	}

 	sg_init_one(&ctx->u.sha.opad_sg, ctx->u.sha.opad, block_size);
 	ctx->u.sha.opad_count = block_size;

 	ctx->u.sha.key_len = key_len;

 	return 0;
 }

 static int ccp_sha_cra_init(struct crypto_tfm *tfm)
 {
 	struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
 	struct crypto_ahash *ahash = __crypto_ahash_cast(tfm);

 	ctx->complete = ccp_sha_complete;
 	ctx->u.sha.key_len = 0;

 	crypto_ahash_set_reqsize(ahash, sizeof(struct ccp_sha_req_ctx));

 	return 0;
 }

 static void ccp_sha_cra_exit(struct crypto_tfm *tfm)
 {
 }

 static int ccp_hmac_sha_cra_init(struct crypto_tfm *tfm)
 {
 	struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
 	struct ccp_crypto_ahash_alg *alg = ccp_crypto_ahash_alg(tfm);
 	struct crypto_shash *hmac_tfm;

 	hmac_tfm = crypto_alloc_shash(alg->child_alg, 0, 0);
 	if (IS_ERR(hmac_tfm)) {
 		pr_warn("could not load driver %s need for HMAC support\n",
 			alg->child_alg);
 		return PTR_ERR(hmac_tfm);
 	}

 	ctx->u.sha.hmac_tfm = hmac_tfm;

 	return ccp_sha_cra_init(tfm);
 }

 static void ccp_hmac_sha_cra_exit(struct crypto_tfm *tfm)
 {
 	struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);

 	if (ctx->u.sha.hmac_tfm)
 		crypto_free_shash(ctx->u.sha.hmac_tfm);

 	ccp_sha_cra_exit(tfm);
 }

 struct ccp_sha_def {
 	const char *name;
 	const char *drv_name;
 	enum ccp_sha_type type;
 	u32 digest_size;
 	u32 block_size;
 };

 static struct ccp_sha_def sha_algs[] = {
 	{
 		.name		= "sha1",
 		.drv_name	= "sha1-ccp",
 		.type		= CCP_SHA_TYPE_1,
 		.digest_size	= SHA1_DIGEST_SIZE,
 		.block_size	= SHA1_BLOCK_SIZE,
 	},
 	{
 		.name		= "sha224",
 		.drv_name	= "sha224-ccp",
 		.type		= CCP_SHA_TYPE_224,
 		.digest_size	= SHA224_DIGEST_SIZE,
 		.block_size	= SHA224_BLOCK_SIZE,
 	},
 	{
 		.name		= "sha256",
 		.drv_name	= "sha256-ccp",
 		.type		= CCP_SHA_TYPE_256,
 		.digest_size	= SHA256_DIGEST_SIZE,
 		.block_size	= SHA256_BLOCK_SIZE,
 	},
 };

 static int ccp_register_hmac_alg(struct list_head *head,
 				 const struct ccp_sha_def *def,
 				 const struct ccp_crypto_ahash_alg *base_alg)
 {
 	struct ccp_crypto_ahash_alg *ccp_alg;
 	struct ahash_alg *alg;
 	struct hash_alg_common *halg;
 	struct crypto_alg *base;
 	int ret;

 	ccp_alg = kzalloc(sizeof(*ccp_alg), GFP_KERNEL);
 	if (!ccp_alg)
 		return -ENOMEM;

 	/* Copy the base algorithm and only change what's necessary */
 	*ccp_alg = *base_alg;
 	INIT_LIST_HEAD(&ccp_alg->entry);

 	strncpy(ccp_alg->child_alg, def->name, CRYPTO_MAX_ALG_NAME);

 	alg = &ccp_alg->alg;
 	alg->setkey = ccp_sha_setkey;

 	halg = &alg->halg;

 	base = &halg->base;
 	snprintf(base->cra_name, CRYPTO_MAX_ALG_NAME, "hmac(%s)", def->name);
 	snprintf(base->cra_driver_name, CRYPTO_MAX_ALG_NAME, "hmac-%s",
 		 def->drv_name);
 	base->cra_init = ccp_hmac_sha_cra_init;
 	base->cra_exit = ccp_hmac_sha_cra_exit;

 	ret = crypto_register_ahash(alg);
 	if (ret) {
 		pr_err("%s ahash algorithm registration error (%d)\n",
 			base->cra_name, ret);
 		kfree(ccp_alg);
 		return ret;
 	}

 	list_add(&ccp_alg->entry, head);

 	return ret;
 }

 static int ccp_register_sha_alg(struct list_head *head,
 				const struct ccp_sha_def *def)
 {
 	struct ccp_crypto_ahash_alg *ccp_alg;
 	struct ahash_alg *alg;
 	struct hash_alg_common *halg;
 	struct crypto_alg *base;
 	int ret;

 	ccp_alg = kzalloc(sizeof(*ccp_alg), GFP_KERNEL);
 	if (!ccp_alg)
 		return -ENOMEM;

 	INIT_LIST_HEAD(&ccp_alg->entry);

 	ccp_alg->type = def->type;

 	alg = &ccp_alg->alg;
 	alg->init = ccp_sha_init;
 	alg->update = ccp_sha_update;
 	alg->final = ccp_sha_final;
 	alg->finup = ccp_sha_finup;
 	alg->digest = ccp_sha_digest;

 	halg = &alg->halg;
 	halg->digestsize = def->digest_size;

 	base = &halg->base;
 	snprintf(base->cra_name, CRYPTO_MAX_ALG_NAME, "%s", def->name);
 	snprintf(base->cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s",
 		 def->drv_name);
 	base->cra_flags = CRYPTO_ALG_TYPE_AHASH | CRYPTO_ALG_ASYNC |
 			  CRYPTO_ALG_KERN_DRIVER_ONLY |
 			  CRYPTO_ALG_NEED_FALLBACK;
 	base->cra_blocksize = def->block_size;
 	base->cra_ctxsize = sizeof(struct ccp_ctx);
 	base->cra_priority = CCP_CRA_PRIORITY;
 	base->cra_type = &crypto_ahash_type;
 	base->cra_init = ccp_sha_cra_init;
 	base->cra_exit = ccp_sha_cra_exit;
 	base->cra_module = THIS_MODULE;

 	ret = crypto_register_ahash(alg);
 	if (ret) {
 		pr_err("%s ahash algorithm registration error (%d)\n",
 			base->cra_name, ret);
 		kfree(ccp_alg);
 		return ret;
 	}

 	list_add(&ccp_alg->entry, head);

 	ret = ccp_register_hmac_alg(head, def, ccp_alg);

 	return ret;
 }

 int ccp_register_sha_algs(struct list_head *head)
 {
 	int i, ret;

 	for (i = 0; i < ARRAY_SIZE(sha_algs); i++) {
 		ret = ccp_register_sha_alg(head, &sha_algs[i]);
 		if (ret)
 			return ret;
 	}

 	return 0;
 }
	/*
	* AMD Cryptographic Coprocessor (CCP) SHA crypto API support
	*
	* Copyright (C) 2013 Advanced Micro Devices, Inc.
	*
	* Author: Tom Lendacky <thomas.lendacky@amd.com>
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*/

	#include <linux/module.h>
	#include <linux/sched.h>
	#include <linux/delay.h>
	#include <linux/scatterlist.h>
	#include <linux/crypto.h>
	#include <crypto/algapi.h>
	#include <crypto/hash.h>
	#include <crypto/internal/hash.h>
	#include <crypto/sha.h>
	#include <crypto/scatterwalk.h>

	#include "ccp-crypto.h"


	static int ccp_sha_complete(struct crypto_async_request *async_req, int ret)
	{
	struct ahash_request *req = ahash_request_cast(async_req);
	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
	struct ccp_sha_req_ctx *rctx = ahash_request_ctx(req);
	unsigned int digest_size = crypto_ahash_digestsize(tfm);

	if (ret)
	goto e_free;

	if (rctx->hash_rem) {
	/* Save remaining data to buffer */
	unsigned int offset = rctx->nbytes - rctx->hash_rem;
	scatterwalk_map_and_copy(rctx->buf, rctx->src,
	offset, rctx->hash_rem, 0);
	rctx->buf_count = rctx->hash_rem;
	} else
	rctx->buf_count = 0;

	/* Update result area if supplied */
	if (req->result)
	memcpy(req->result, rctx->ctx, digest_size);

	e_free:
	sg_free_table(&rctx->data_sg);

	return ret;
	}

	static int ccp_do_sha_update(struct ahash_request *req, unsigned int nbytes,
	unsigned int final)
	{
	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
	struct ccp_ctx *ctx = crypto_ahash_ctx(tfm);
	struct ccp_sha_req_ctx *rctx = ahash_request_ctx(req);
	struct scatterlist *sg;
	unsigned int block_size =
	crypto_tfm_alg_blocksize(crypto_ahash_tfm(tfm));
	unsigned int sg_count;
	gfp_t gfp;
	u64 len;
	int ret;

	len = (u64)rctx->buf_count + (u64)nbytes;

	if (!final && (len <= block_size)) {
	scatterwalk_map_and_copy(rctx->buf + rctx->buf_count, req->src,
	0, nbytes, 0);
	rctx->buf_count += nbytes;

	return 0;
	}

	rctx->src = req->src;
	rctx->nbytes = nbytes;

	rctx->final = final;
	rctx->hash_rem = final ? 0 : len & (block_size - 1);
	rctx->hash_cnt = len - rctx->hash_rem;
	if (!final && !rctx->hash_rem) {
	/* CCP can't do zero length final, so keep some data around */
	rctx->hash_cnt -= block_size;
	rctx->hash_rem = block_size;
	}

	/* Initialize the context scatterlist */
	sg_init_one(&rctx->ctx_sg, rctx->ctx, sizeof(rctx->ctx));

	sg = NULL;
	if (rctx->buf_count && nbytes) {
	/* Build the data scatterlist table - allocate enough entries
	* for both data pieces (buffer and input data)
	*/
	gfp = req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ?
	GFP_KERNEL : GFP_ATOMIC;
	sg_count = sg_nents(req->src) + 1;
	ret = sg_alloc_table(&rctx->data_sg, sg_count, gfp);
	if (ret)
	return ret;

	sg_init_one(&rctx->buf_sg, rctx->buf, rctx->buf_count);
	sg = ccp_crypto_sg_table_add(&rctx->data_sg, &rctx->buf_sg);
	sg = ccp_crypto_sg_table_add(&rctx->data_sg, req->src);
	sg_mark_end(sg);

	sg = rctx->data_sg.sgl;
	} else if (rctx->buf_count) {
	sg_init_one(&rctx->buf_sg, rctx->buf, rctx->buf_count);

	sg = &rctx->buf_sg;
	} else if (nbytes) {
	sg = req->src;
	}

	rctx->msg_bits += (rctx->hash_cnt << 3); /* Total in bits */

	memset(&rctx->cmd, 0, sizeof(rctx->cmd));
	INIT_LIST_HEAD(&rctx->cmd.entry);
	rctx->cmd.engine = CCP_ENGINE_SHA;
	rctx->cmd.u.sha.type = rctx->type;
	rctx->cmd.u.sha.ctx = &rctx->ctx_sg;
	rctx->cmd.u.sha.ctx_len = sizeof(rctx->ctx);
	rctx->cmd.u.sha.src = sg;
	rctx->cmd.u.sha.src_len = rctx->hash_cnt;
	rctx->cmd.u.sha.opad = ctx->u.sha.key_len ?
	&ctx->u.sha.opad_sg : NULL;
	rctx->cmd.u.sha.opad_len = ctx->u.sha.key_len ?
	ctx->u.sha.opad_count : 0;
	rctx->cmd.u.sha.first = rctx->first;
	rctx->cmd.u.sha.final = rctx->final;
	rctx->cmd.u.sha.msg_bits = rctx->msg_bits;

	rctx->first = 0;

	ret = ccp_crypto_enqueue_request(&req->base, &rctx->cmd);

	return ret;
	}

	static int ccp_sha_init(struct ahash_request *req)
	{
	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
	struct ccp_ctx *ctx = crypto_ahash_ctx(tfm);
	struct ccp_sha_req_ctx *rctx = ahash_request_ctx(req);
	struct ccp_crypto_ahash_alg *alg =
	ccp_crypto_ahash_alg(crypto_ahash_tfm(tfm));
	unsigned int block_size =
	crypto_tfm_alg_blocksize(crypto_ahash_tfm(tfm));

	memset(rctx, 0, sizeof(*rctx));

	rctx->type = alg->type;
	rctx->first = 1;

	if (ctx->u.sha.key_len) {
	/* Buffer the HMAC key for first update */
	memcpy(rctx->buf, ctx->u.sha.ipad, block_size);
	rctx->buf_count = block_size;
	}

	return 0;
	}

	static int ccp_sha_update(struct ahash_request *req)
	{
	return ccp_do_sha_update(req, req->nbytes, 0);
	}

	static int ccp_sha_final(struct ahash_request *req)
	{
	return ccp_do_sha_update(req, 0, 1);
	}

	static int ccp_sha_finup(struct ahash_request *req)
	{
	return ccp_do_sha_update(req, req->nbytes, 1);
	}

	static int ccp_sha_digest(struct ahash_request *req)
	{
	int ret;

	ret = ccp_sha_init(req);
	if (ret)
	return ret;

	return ccp_sha_finup(req);
	}

	static int ccp_sha_setkey(struct crypto_ahash tfm, const u8 key,
	unsigned int key_len)
	{
	struct ccp_ctx *ctx = crypto_tfm_ctx(crypto_ahash_tfm(tfm));
	struct crypto_shash *shash = ctx->u.sha.hmac_tfm;
	struct {
	struct shash_desc sdesc;
	char ctx[crypto_shash_descsize(shash)];
	} desc;
	unsigned int block_size = crypto_shash_blocksize(shash);
	unsigned int digest_size = crypto_shash_digestsize(shash);
	int i, ret;

	/* Set to zero until complete */
	ctx->u.sha.key_len = 0;

	/* Clear key area to provide zero padding for keys smaller
	* than the block size
	*/
	memset(ctx->u.sha.key, 0, sizeof(ctx->u.sha.key));

	if (key_len > block_size) {
	/* Must hash the input key */
	desc.sdesc.tfm = shash;
	desc.sdesc.flags = crypto_ahash_get_flags(tfm) &
	CRYPTO_TFM_REQ_MAY_SLEEP;

	ret = crypto_shash_digest(&desc.sdesc, key, key_len,
	ctx->u.sha.key);
	if (ret) {
	crypto_ahash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
	return -EINVAL;
	}

	key_len = digest_size;
	} else
	memcpy(ctx->u.sha.key, key, key_len);

	for (i = 0; i < block_size; i++) {
	ctx->u.sha.ipad[i] = ctx->u.sha.key[i] ^ 0x36;
	ctx->u.sha.opad[i] = ctx->u.sha.key[i] ^ 0x5c;
	}

	sg_init_one(&ctx->u.sha.opad_sg, ctx->u.sha.opad, block_size);
	ctx->u.sha.opad_count = block_size;

	ctx->u.sha.key_len = key_len;

	return 0;
	}

	static int ccp_sha_cra_init(struct crypto_tfm *tfm)
	{
	struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
	struct crypto_ahash *ahash = __crypto_ahash_cast(tfm);

	ctx->complete = ccp_sha_complete;
	ctx->u.sha.key_len = 0;

	crypto_ahash_set_reqsize(ahash, sizeof(struct ccp_sha_req_ctx));

	return 0;
	}

	static void ccp_sha_cra_exit(struct crypto_tfm *tfm)
	{
	}

	static int ccp_hmac_sha_cra_init(struct crypto_tfm *tfm)
	{
	struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
	struct ccp_crypto_ahash_alg *alg = ccp_crypto_ahash_alg(tfm);
	struct crypto_shash *hmac_tfm;

	hmac_tfm = crypto_alloc_shash(alg->child_alg, 0, 0);
	if (IS_ERR(hmac_tfm)) {
	pr_warn("could not load driver %s need for HMAC support\n",
	alg->child_alg);
	return PTR_ERR(hmac_tfm);
	}

	ctx->u.sha.hmac_tfm = hmac_tfm;

	return ccp_sha_cra_init(tfm);
	}

	static void ccp_hmac_sha_cra_exit(struct crypto_tfm *tfm)
	{
	struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);

	if (ctx->u.sha.hmac_tfm)
	crypto_free_shash(ctx->u.sha.hmac_tfm);

	ccp_sha_cra_exit(tfm);
	}

	struct ccp_sha_def {
	const char *name;
	const char *drv_name;
	enum ccp_sha_type type;
	u32 digest_size;
	u32 block_size;
	};

	static struct ccp_sha_def sha_algs[] = {
	{
	.name = "sha1",
	.drv_name = "sha1-ccp",
	.type = CCP_SHA_TYPE_1,
	.digest_size = SHA1_DIGEST_SIZE,
	.block_size = SHA1_BLOCK_SIZE,
	},
	{
	.name = "sha224",
	.drv_name = "sha224-ccp",
	.type = CCP_SHA_TYPE_224,
	.digest_size = SHA224_DIGEST_SIZE,
	.block_size = SHA224_BLOCK_SIZE,
	},
	{
	.name = "sha256",
	.drv_name = "sha256-ccp",
	.type = CCP_SHA_TYPE_256,
	.digest_size = SHA256_DIGEST_SIZE,
	.block_size = SHA256_BLOCK_SIZE,
	},
	};

	static int ccp_register_hmac_alg(struct list_head *head,
	const struct ccp_sha_def *def,
	const struct ccp_crypto_ahash_alg *base_alg)
	{
	struct ccp_crypto_ahash_alg *ccp_alg;
	struct ahash_alg *alg;
	struct hash_alg_common *halg;
	struct crypto_alg *base;
	int ret;

	ccp_alg = kzalloc(sizeof(*ccp_alg), GFP_KERNEL);
	if (!ccp_alg)
	return -ENOMEM;

	/* Copy the base algorithm and only change what's necessary */
	ccp_alg = base_alg;
	INIT_LIST_HEAD(&ccp_alg->entry);

	strncpy(ccp_alg->child_alg, def->name, CRYPTO_MAX_ALG_NAME);

	alg = &ccp_alg->alg;
	alg->setkey = ccp_sha_setkey;

	halg = &alg->halg;

	base = &halg->base;
	snprintf(base->cra_name, CRYPTO_MAX_ALG_NAME, "hmac(%s)", def->name);
	snprintf(base->cra_driver_name, CRYPTO_MAX_ALG_NAME, "hmac-%s",
	def->drv_name);
	base->cra_init = ccp_hmac_sha_cra_init;
	base->cra_exit = ccp_hmac_sha_cra_exit;

	ret = crypto_register_ahash(alg);
	if (ret) {
	pr_err("%s ahash algorithm registration error (%d)\n",
	base->cra_name, ret);
	kfree(ccp_alg);
	return ret;
	}

	list_add(&ccp_alg->entry, head);

	return ret;
	}

	static int ccp_register_sha_alg(struct list_head *head,
	const struct ccp_sha_def *def)
	{
	struct ccp_crypto_ahash_alg *ccp_alg;
	struct ahash_alg *alg;
	struct hash_alg_common *halg;
	struct crypto_alg *base;
	int ret;

	ccp_alg = kzalloc(sizeof(*ccp_alg), GFP_KERNEL);
	if (!ccp_alg)
	return -ENOMEM;

	INIT_LIST_HEAD(&ccp_alg->entry);

	ccp_alg->type = def->type;

	alg = &ccp_alg->alg;
	alg->init = ccp_sha_init;
	alg->update = ccp_sha_update;
	alg->final = ccp_sha_final;
	alg->finup = ccp_sha_finup;
	alg->digest = ccp_sha_digest;

	halg = &alg->halg;
	halg->digestsize = def->digest_size;

	base = &halg->base;
	snprintf(base->cra_name, CRYPTO_MAX_ALG_NAME, "%s", def->name);
	snprintf(base->cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s",
	def->drv_name);
	base->cra_flags = CRYPTO_ALG_TYPE_AHASH \| CRYPTO_ALG_ASYNC \|
	CRYPTO_ALG_KERN_DRIVER_ONLY \|
	CRYPTO_ALG_NEED_FALLBACK;
	base->cra_blocksize = def->block_size;
	base->cra_ctxsize = sizeof(struct ccp_ctx);
	base->cra_priority = CCP_CRA_PRIORITY;
	base->cra_type = &crypto_ahash_type;
	base->cra_init = ccp_sha_cra_init;
	base->cra_exit = ccp_sha_cra_exit;
	base->cra_module = THIS_MODULE;

	ret = crypto_register_ahash(alg);
	if (ret) {
	pr_err("%s ahash algorithm registration error (%d)\n",
	base->cra_name, ret);
	kfree(ccp_alg);
	return ret;
	}

	list_add(&ccp_alg->entry, head);

	ret = ccp_register_hmac_alg(head, def, ccp_alg);

	return ret;
	}

	int ccp_register_sha_algs(struct list_head *head)
	{
	int i, ret;

	for (i = 0; i < ARRAY_SIZE(sha_algs); i++) {
	ret = ccp_register_sha_alg(head, &sha_algs[i]);
	if (ret)
	return ret;
	}

	return 0;
	}