crypto: ccp - CCP SHA crypto API support

/*

 * 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"

struct ccp_sha_result {

	struct completion completion;

	int err;

};

static void ccp_sync_hash_complete(struct crypto_async_request *req, int err)

{

	struct ccp_sha_result *result = req->data;

	if (err == -EINPROGRESS)

		return;

	result->err = err;

	complete(&result->completion);

}

static int ccp_sync_hash(struct crypto_ahash *tfm, u8 *buf,

			 struct scatterlist *sg, unsigned int len)

{

	struct ccp_sha_result result;

	struct ahash_request *req;

	int ret;

	init_completion(&result.completion);

	req = ahash_request_alloc(tfm, GFP_KERNEL);

	if (!req)

		return -ENOMEM;

	ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,

				   ccp_sync_hash_complete, &result);

	ahash_request_set_crypt(req, sg, buf, len);

	ret = crypto_ahash_digest(req);

	if ((ret == -EINPROGRESS) || (ret == -EBUSY)) {

		ret = wait_for_completion_interruptible(&result.completion);

		if (!ret)

			ret = result.err;

	}

	ahash_request_free(req);

	return ret;

}

static int ccp_sha_finish_hmac(struct crypto_async_request *async_req)

{

	struct ahash_request *req = ahash_request_cast(async_req);

	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);

	struct ccp_ctx *ctx = crypto_ahash_ctx(tfm);

	struct scatterlist sg[2];

	unsigned int block_size =

		crypto_tfm_alg_blocksize(crypto_ahash_tfm(tfm));

	unsigned int digest_size = crypto_ahash_digestsize(tfm);

	sg_init_table(sg, ARRAY_SIZE(sg));

	sg_set_buf(&sg[0], ctx->u.sha.opad, block_size);

	sg_set_buf(&sg[1], req->result, digest_size);

	return ccp_sync_hash(ctx->u.sha.hmac_tfm, req->result, sg,

			     block_size + digest_size);

}

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_ctx *ctx = crypto_ahash_ctx(tfm);

	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 */

		scatterwalk_map_and_copy(rctx->buf, rctx->cmd.u.sha.src,

					 rctx->hash_cnt, rctx->hash_rem, 0);

		rctx->buf_count = rctx->hash_rem;

	} else

		rctx->buf_count = 0;

	memcpy(req->result, rctx->ctx, digest_size);

	/* If we're doing an HMAC, we need to perform that on the final op */

	if (rctx->final && ctx->u.sha.key_len)

		ret = ccp_sha_finish_hmac(async_req);

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 len, sg_count;

	int ret;

	if (!final && ((nbytes + rctx->buf_count) <= block_size)) {

		scatterwalk_map_and_copy(rctx->buf + rctx->buf_count, req->src,

					 0, nbytes, 0);

		rctx->buf_count += nbytes;

		return 0;

	}

	len = rctx->buf_count + nbytes;

	rctx->final = final;

	rctx->hash_cnt = final ? len : len & ~(block_size - 1);

	rctx->hash_rem = final ?   0 : len &  (block_size - 1);

	if (!final && (rctx->hash_cnt == len)) {

		/* 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));

	/* Build the data scatterlist table - allocate enough entries for all

	 * possible data pieces (hmac ipad, buffer, input data)

	 */

	sg_count = (nbytes) ? sg_nents(req->src) + 2 : 2;

	ret = sg_alloc_table(&rctx->data_sg, sg_count, GFP_KERNEL);

	if (ret)

		return ret;

	sg = NULL;

	if (rctx->first && ctx->u.sha.key_len) {

		rctx->hash_cnt += block_size;

		sg_init_one(&rctx->pad_sg, ctx->u.sha.ipad, block_size);

		sg = ccp_crypto_sg_table_add(&rctx->data_sg, &rctx->pad_sg);

	}

	if (rctx->buf_count) {

		sg_init_one(&rctx->buf_sg, rctx->buf, rctx->buf_count);

		sg = ccp_crypto_sg_table_add(&rctx->data_sg, &rctx->buf_sg);

	}

	if (nbytes)

		sg = ccp_crypto_sg_table_add(&rctx->data_sg, req->src);

	if (sg)

		sg_mark_end(sg);

	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->data_sg.sgl : NULL;

	rctx->cmd.u.sha.src_len = rctx->hash_cnt;

	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_sha_req_ctx *rctx = ahash_request_ctx(req);

	struct ccp_crypto_ahash_alg *alg =

		ccp_crypto_ahash_alg(crypto_ahash_tfm(tfm));

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

	memcpy(rctx->ctx, alg->init, sizeof(rctx->ctx));

	rctx->type = alg->type;

	rctx->first = 1;

	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)

{

	ccp_sha_init(req);

	return ccp_do_sha_update(req, req->nbytes, 1);

}

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 scatterlist sg;

	unsigned int block_size =

		crypto_tfm_alg_blocksize(crypto_ahash_tfm(tfm));

	unsigned int digest_size = crypto_ahash_digestsize(tfm);

	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 */

		sg_init_one(&sg, key, key_len);

		ret = ccp_sync_hash(tfm, ctx->u.sha.key, &sg, key_len);

		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;

	}

	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_ahash *hmac_tfm;

	hmac_tfm = crypto_alloc_ahash(alg->child_alg,

				      CRYPTO_ALG_TYPE_AHASH, 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_ahash(ctx->u.sha.hmac_tfm);

	ccp_sha_cra_exit(tfm);

}

static const u32 sha1_init[CCP_SHA_CTXSIZE / sizeof(u32)] = {

	cpu_to_be32(SHA1_H0), cpu_to_be32(SHA1_H1),

	cpu_to_be32(SHA1_H2), cpu_to_be32(SHA1_H3),

	cpu_to_be32(SHA1_H4), 0, 0, 0,

};

static const u32 sha224_init[CCP_SHA_CTXSIZE / sizeof(u32)] = {

	cpu_to_be32(SHA224_H0), cpu_to_be32(SHA224_H1),

	cpu_to_be32(SHA224_H2), cpu_to_be32(SHA224_H3),

	cpu_to_be32(SHA224_H4), cpu_to_be32(SHA224_H5),

	cpu_to_be32(SHA224_H6), cpu_to_be32(SHA224_H7),

};

static const u32 sha256_init[CCP_SHA_CTXSIZE / sizeof(u32)] = {

	cpu_to_be32(SHA256_H0), cpu_to_be32(SHA256_H1),

	cpu_to_be32(SHA256_H2), cpu_to_be32(SHA256_H3),

	cpu_to_be32(SHA256_H4), cpu_to_be32(SHA256_H5),

	cpu_to_be32(SHA256_H6), cpu_to_be32(SHA256_H7),

};

struct ccp_sha_def {

	const char *name;

	const char *drv_name;

	const u32 *init;

	enum ccp_sha_type type;

	u32 digest_size;

	u32 block_size;

};

static struct ccp_sha_def sha_algs[] = {

	{

		.name		= "sha1",

		.drv_name	= "sha1-ccp",

		.init		= sha1_init,

		.type		= CCP_SHA_TYPE_1,

		.digest_size	= SHA1_DIGEST_SIZE,

		.block_size	= SHA1_BLOCK_SIZE,

	},

	{

		.name		= "sha224",

		.drv_name	= "sha224-ccp",

		.init		= sha224_init,

		.type		= CCP_SHA_TYPE_224,

		.digest_size	= SHA224_DIGEST_SIZE,

		.block_size	= SHA224_BLOCK_SIZE,

	},

	{

		.name		= "sha256",

		.drv_name	= "sha256-ccp",

		.init		= sha256_init,

		.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 */

	memcpy(ccp_alg, base_alg, sizeof(*ccp_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->init = def->init;

	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;

}