crypto: ccp - CCP AES crypto API support

These routines provide crypto API support for AES on the AMD CCP.

Support for AES modes: ECB, CBC, OFB, CFB and CTR
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/ccp/ccp-crypto-aes.c

+/*
+ * AMD Cryptographic Coprocessor (CCP) AES 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/aes.h>
+#include <crypto/ctr.h>
+#include <crypto/scatterwalk.h>
+
+#include "ccp-crypto.h"
+
+
+static int ccp_aes_complete(struct crypto_async_request *async_req, int ret)
+{
+	struct ablkcipher_request *req = ablkcipher_request_cast(async_req);
+	struct ccp_ctx *ctx = crypto_tfm_ctx(req->base.tfm);
+	struct ccp_aes_req_ctx *rctx = ablkcipher_request_ctx(req);
+
+	if (ret)
+		return ret;
+
+	if (ctx->u.aes.mode != CCP_AES_MODE_ECB)
+		memcpy(req->info, rctx->iv, AES_BLOCK_SIZE);
+
+	return 0;
+}
+
+static int ccp_aes_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
+			  unsigned int key_len)
+{
+	struct ccp_ctx *ctx = crypto_tfm_ctx(crypto_ablkcipher_tfm(tfm));
+	struct ccp_crypto_ablkcipher_alg *alg =
+		ccp_crypto_ablkcipher_alg(crypto_ablkcipher_tfm(tfm));
+
+	switch (key_len) {
+	case AES_KEYSIZE_128:
+		ctx->u.aes.type = CCP_AES_TYPE_128;
+		break;
+	case AES_KEYSIZE_192:
+		ctx->u.aes.type = CCP_AES_TYPE_192;
+		break;
+	case AES_KEYSIZE_256:
+		ctx->u.aes.type = CCP_AES_TYPE_256;
+		break;
+	default:
+		crypto_ablkcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
+		return -EINVAL;
+	}
+	ctx->u.aes.mode = alg->mode;
+	ctx->u.aes.key_len = key_len;
+
+	memcpy(ctx->u.aes.key, key, key_len);
+	sg_init_one(&ctx->u.aes.key_sg, ctx->u.aes.key, key_len);
+
+	return 0;
+}
+
+static int ccp_aes_crypt(struct ablkcipher_request *req, bool encrypt)
+{
+	struct ccp_ctx *ctx = crypto_tfm_ctx(req->base.tfm);
+	struct ccp_aes_req_ctx *rctx = ablkcipher_request_ctx(req);
+	struct scatterlist *iv_sg = NULL;
+	unsigned int iv_len = 0;
+	int ret;
+
+	if (!ctx->u.aes.key_len) {
+		pr_err("AES key not set\n");
+		return -EINVAL;
+	}
+
+	if (((ctx->u.aes.mode == CCP_AES_MODE_ECB) ||
+	     (ctx->u.aes.mode == CCP_AES_MODE_CBC) ||
+	     (ctx->u.aes.mode == CCP_AES_MODE_CFB)) &&
+	    (req->nbytes & (AES_BLOCK_SIZE - 1))) {
+		pr_err("AES request size is not a multiple of the block size\n");
+		return -EINVAL;
+	}
+
+	if (ctx->u.aes.mode != CCP_AES_MODE_ECB) {
+		if (!req->info) {
+			pr_err("AES IV not supplied");
+			return -EINVAL;
+		}
+
+		memcpy(rctx->iv, req->info, AES_BLOCK_SIZE);
+		iv_sg = &rctx->iv_sg;
+		iv_len = AES_BLOCK_SIZE;
+		sg_init_one(iv_sg, rctx->iv, iv_len);
+	}
+
+	memset(&rctx->cmd, 0, sizeof(rctx->cmd));
+	INIT_LIST_HEAD(&rctx->cmd.entry);
+	rctx->cmd.engine = CCP_ENGINE_AES;
+	rctx->cmd.u.aes.type = ctx->u.aes.type;
+	rctx->cmd.u.aes.mode = ctx->u.aes.mode;
+	rctx->cmd.u.aes.action =
+		(encrypt) ? CCP_AES_ACTION_ENCRYPT : CCP_AES_ACTION_DECRYPT;
+	rctx->cmd.u.aes.key = &ctx->u.aes.key_sg;
+	rctx->cmd.u.aes.key_len = ctx->u.aes.key_len;
+	rctx->cmd.u.aes.iv = iv_sg;
+	rctx->cmd.u.aes.iv_len = iv_len;
+	rctx->cmd.u.aes.src = req->src;
+	rctx->cmd.u.aes.src_len = req->nbytes;
+	rctx->cmd.u.aes.dst = req->dst;
+
+	ret = ccp_crypto_enqueue_request(&req->base, &rctx->cmd);
+
+	return ret;
+}
+
+static int ccp_aes_encrypt(struct ablkcipher_request *req)
+{
+	return ccp_aes_crypt(req, true);
+}
+
+static int ccp_aes_decrypt(struct ablkcipher_request *req)
+{
+	return ccp_aes_crypt(req, false);
+}
+
+static int ccp_aes_cra_init(struct crypto_tfm *tfm)
+{
+	struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	ctx->complete = ccp_aes_complete;
+	ctx->u.aes.key_len = 0;
+
+	tfm->crt_ablkcipher.reqsize = sizeof(struct ccp_aes_req_ctx);
+
+	return 0;
+}
+
+static void ccp_aes_cra_exit(struct crypto_tfm *tfm)
+{
+}
+
+static int ccp_aes_rfc3686_complete(struct crypto_async_request *async_req,
+				    int ret)
+{
+	struct ablkcipher_request *req = ablkcipher_request_cast(async_req);
+	struct ccp_aes_req_ctx *rctx = ablkcipher_request_ctx(req);
+
+	/* Restore the original pointer */
+	req->info = rctx->rfc3686_info;
+
+	return ccp_aes_complete(async_req, ret);
+}
+
+static int ccp_aes_rfc3686_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
+				  unsigned int key_len)
+{
+	struct ccp_ctx *ctx = crypto_tfm_ctx(crypto_ablkcipher_tfm(tfm));
+
+	if (key_len < CTR_RFC3686_NONCE_SIZE)
+		return -EINVAL;
+
+	key_len -= CTR_RFC3686_NONCE_SIZE;
+	memcpy(ctx->u.aes.nonce, key + key_len, CTR_RFC3686_NONCE_SIZE);
+
+	return ccp_aes_setkey(tfm, key, key_len);
+}
+
+static int ccp_aes_rfc3686_crypt(struct ablkcipher_request *req, bool encrypt)
+{
+	struct ccp_ctx *ctx = crypto_tfm_ctx(req->base.tfm);
+	struct ccp_aes_req_ctx *rctx = ablkcipher_request_ctx(req);
+	u8 *iv;
+
+	/* Initialize the CTR block */
+	iv = rctx->rfc3686_iv;
+	memcpy(iv, ctx->u.aes.nonce, CTR_RFC3686_NONCE_SIZE);
+
+	iv += CTR_RFC3686_NONCE_SIZE;
+	memcpy(iv, req->info, CTR_RFC3686_IV_SIZE);
+
+	iv += CTR_RFC3686_IV_SIZE;
+	*(__be32 *)iv = cpu_to_be32(1);
+
+	/* Point to the new IV */
+	rctx->rfc3686_info = req->info;
+	req->info = rctx->rfc3686_iv;
+
+	return ccp_aes_crypt(req, encrypt);
+}
+
+static int ccp_aes_rfc3686_encrypt(struct ablkcipher_request *req)
+{
+	return ccp_aes_rfc3686_crypt(req, true);
+}
+
+static int ccp_aes_rfc3686_decrypt(struct ablkcipher_request *req)
+{
+	return ccp_aes_rfc3686_crypt(req, false);
+}
+
+static int ccp_aes_rfc3686_cra_init(struct crypto_tfm *tfm)
+{
+	struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	ctx->complete = ccp_aes_rfc3686_complete;
+	ctx->u.aes.key_len = 0;
+
+	tfm->crt_ablkcipher.reqsize = sizeof(struct ccp_aes_req_ctx);
+
+	return 0;
+}
+
+static void ccp_aes_rfc3686_cra_exit(struct crypto_tfm *tfm)
+{
+}
+
+static struct crypto_alg ccp_aes_defaults = {
+	.cra_flags	= CRYPTO_ALG_TYPE_ABLKCIPHER |
+			  CRYPTO_ALG_ASYNC |
+			  CRYPTO_ALG_KERN_DRIVER_ONLY |
+			  CRYPTO_ALG_NEED_FALLBACK,
+	.cra_blocksize	= AES_BLOCK_SIZE,
+	.cra_ctxsize	= sizeof(struct ccp_ctx),
+	.cra_priority	= CCP_CRA_PRIORITY,
+	.cra_type	= &crypto_ablkcipher_type,
+	.cra_init	= ccp_aes_cra_init,
+	.cra_exit	= ccp_aes_cra_exit,
+	.cra_module	= THIS_MODULE,
+	.cra_ablkcipher	= {
+		.setkey		= ccp_aes_setkey,
+		.encrypt	= ccp_aes_encrypt,
+		.decrypt	= ccp_aes_decrypt,
+		.min_keysize	= AES_MIN_KEY_SIZE,
+		.max_keysize	= AES_MAX_KEY_SIZE,
+	},
+};
+
+static struct crypto_alg ccp_aes_rfc3686_defaults = {
+	.cra_flags	= CRYPTO_ALG_TYPE_ABLKCIPHER |
+			   CRYPTO_ALG_ASYNC |
+			   CRYPTO_ALG_KERN_DRIVER_ONLY |
+			   CRYPTO_ALG_NEED_FALLBACK,
+	.cra_blocksize	= CTR_RFC3686_BLOCK_SIZE,
+	.cra_ctxsize	= sizeof(struct ccp_ctx),
+	.cra_priority	= CCP_CRA_PRIORITY,
+	.cra_type	= &crypto_ablkcipher_type,
+	.cra_init	= ccp_aes_rfc3686_cra_init,
+	.cra_exit	= ccp_aes_rfc3686_cra_exit,
+	.cra_module	= THIS_MODULE,
+	.cra_ablkcipher	= {
+		.setkey		= ccp_aes_rfc3686_setkey,
+		.encrypt	= ccp_aes_rfc3686_encrypt,
+		.decrypt	= ccp_aes_rfc3686_decrypt,
+		.min_keysize	= AES_MIN_KEY_SIZE + CTR_RFC3686_NONCE_SIZE,
+		.max_keysize	= AES_MAX_KEY_SIZE + CTR_RFC3686_NONCE_SIZE,
+	},
+};
+
+struct ccp_aes_def {
+	enum ccp_aes_mode mode;
+	const char *name;
+	const char *driver_name;
+	unsigned int blocksize;
+	unsigned int ivsize;
+	struct crypto_alg *alg_defaults;
+};
+
+static struct ccp_aes_def aes_algs[] = {
+	{
+		.mode		= CCP_AES_MODE_ECB,
+		.name		= "ecb(aes)",
+		.driver_name	= "ecb-aes-ccp",
+		.blocksize	= AES_BLOCK_SIZE,
+		.ivsize		= 0,
+		.alg_defaults	= &ccp_aes_defaults,
+	},
+	{
+		.mode		= CCP_AES_MODE_CBC,
+		.name		= "cbc(aes)",
+		.driver_name	= "cbc-aes-ccp",
+		.blocksize	= AES_BLOCK_SIZE,
+		.ivsize		= AES_BLOCK_SIZE,
+		.alg_defaults	= &ccp_aes_defaults,
+	},
+	{
+		.mode		= CCP_AES_MODE_CFB,
+		.name		= "cfb(aes)",
+		.driver_name	= "cfb-aes-ccp",
+		.blocksize	= AES_BLOCK_SIZE,
+		.ivsize		= AES_BLOCK_SIZE,
+		.alg_defaults	= &ccp_aes_defaults,
+	},
+	{
+		.mode		= CCP_AES_MODE_OFB,
+		.name		= "ofb(aes)",
+		.driver_name	= "ofb-aes-ccp",
+		.blocksize	= 1,
+		.ivsize		= AES_BLOCK_SIZE,
+		.alg_defaults	= &ccp_aes_defaults,
+	},
+	{
+		.mode		= CCP_AES_MODE_CTR,
+		.name		= "ctr(aes)",
+		.driver_name	= "ctr-aes-ccp",
+		.blocksize	= 1,
+		.ivsize		= AES_BLOCK_SIZE,
+		.alg_defaults	= &ccp_aes_defaults,
+	},
+	{
+		.mode		= CCP_AES_MODE_CTR,
+		.name		= "rfc3686(ctr(aes))",
+		.driver_name	= "rfc3686-ctr-aes-ccp",
+		.blocksize	= 1,
+		.ivsize		= CTR_RFC3686_IV_SIZE,
+		.alg_defaults	= &ccp_aes_rfc3686_defaults,
+	},
+};
+
+static int ccp_register_aes_alg(struct list_head *head,
+				const struct ccp_aes_def *def)
+{
+	struct ccp_crypto_ablkcipher_alg *ccp_alg;
+	struct crypto_alg *alg;
+	int ret;
+
+	ccp_alg = kzalloc(sizeof(*ccp_alg), GFP_KERNEL);
+	if (!ccp_alg)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&ccp_alg->entry);
+
+	ccp_alg->mode = def->mode;
+
+	/* Copy the defaults and override as necessary */
+	alg = &ccp_alg->alg;
+	memcpy(alg, def->alg_defaults, sizeof(*alg));
+	snprintf(alg->cra_name, CRYPTO_MAX_ALG_NAME, "%s", def->name);
+	snprintf(alg->cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s",
+		 def->driver_name);
+	alg->cra_blocksize = def->blocksize;
+	alg->cra_ablkcipher.ivsize = def->ivsize;
+
+	ret = crypto_register_alg(alg);
+	if (ret) {
+		pr_err("%s ablkcipher algorithm registration error (%d)\n",
+			alg->cra_name, ret);
+		kfree(ccp_alg);
+		return ret;
+	}
+
+	list_add(&ccp_alg->entry, head);
+
+	return 0;
+}
+
+int ccp_register_aes_algs(struct list_head *head)
+{
+	int i, ret;
+
+	for (i = 0; i < ARRAY_SIZE(aes_algs); i++) {
+		ret = ccp_register_aes_alg(head, &aes_algs[i]);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}