crypto: ccp - CCP SHA crypto API support

These routines provide crypto API support for SHA1, SHA224 and SHA256
on the AMD CCP.  HMAC support for these SHA modes is also provided.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/ccp/ccp-crypto-sha.c

+/*
+ * 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;
+}