--- /dev/null
+/*
+ * AMD Cryptographic Coprocessor (CCP) AES XTS 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/scatterwalk.h>
+
+#include "ccp-crypto.h"
+
+struct ccp_aes_xts_def {
+ const char *name;
+ const char *drv_name;
+};
+
+static struct ccp_aes_xts_def aes_xts_algs[] = {
+ {
+ .name = "xts(aes)",
+ .drv_name = "xts-aes-ccp",
+ },
+};
+
+struct ccp_unit_size_map {
+ unsigned int size;
+ u32 value;
+};
+
+static struct ccp_unit_size_map unit_size_map[] = {
+ {
+ .size = 4096,
+ .value = CCP_XTS_AES_UNIT_SIZE_4096,
+ },
+ {
+ .size = 2048,
+ .value = CCP_XTS_AES_UNIT_SIZE_2048,
+ },
+ {
+ .size = 1024,
+ .value = CCP_XTS_AES_UNIT_SIZE_1024,
+ },
+ {
+ .size = 512,
+ .value = CCP_XTS_AES_UNIT_SIZE_512,
+ },
+ {
+ .size = 256,
+ .value = CCP_XTS_AES_UNIT_SIZE__LAST,
+ },
+ {
+ .size = 128,
+ .value = CCP_XTS_AES_UNIT_SIZE__LAST,
+ },
+ {
+ .size = 64,
+ .value = CCP_XTS_AES_UNIT_SIZE__LAST,
+ },
+ {
+ .size = 32,
+ .value = CCP_XTS_AES_UNIT_SIZE__LAST,
+ },
+ {
+ .size = 16,
+ .value = CCP_XTS_AES_UNIT_SIZE_16,
+ },
+ {
+ .size = 1,
+ .value = CCP_XTS_AES_UNIT_SIZE__LAST,
+ },
+};
+
+static int ccp_aes_xts_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);
+
+ if (ret)
+ return ret;
+
+ memcpy(req->info, rctx->iv, AES_BLOCK_SIZE);
+
+ return 0;
+}
+
+static int ccp_aes_xts_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
+ unsigned int key_len)
+{
+ struct ccp_ctx *ctx = crypto_tfm_ctx(crypto_ablkcipher_tfm(tfm));
+
+ /* Only support 128-bit AES key with a 128-bit Tweak key,
+ * otherwise use the fallback
+ */
+ switch (key_len) {
+ case AES_KEYSIZE_128 * 2:
+ memcpy(ctx->u.aes.key, key, key_len);
+ break;
+ }
+ ctx->u.aes.key_len = key_len / 2;
+ sg_init_one(&ctx->u.aes.key_sg, ctx->u.aes.key, key_len);
+
+ return crypto_ablkcipher_setkey(ctx->u.aes.tfm_ablkcipher, key,
+ key_len);
+}
+
+static int ccp_aes_xts_crypt(struct ablkcipher_request *req,
+ unsigned int encrypt)
+{
+ struct crypto_tfm *tfm =
+ crypto_ablkcipher_tfm(crypto_ablkcipher_reqtfm(req));
+ struct ccp_ctx *ctx = crypto_tfm_ctx(req->base.tfm);
+ struct ccp_aes_req_ctx *rctx = ablkcipher_request_ctx(req);
+ unsigned int unit;
+ int ret;
+
+ if (!ctx->u.aes.key_len)
+ return -EINVAL;
+
+ if (req->nbytes & (AES_BLOCK_SIZE - 1))
+ return -EINVAL;
+
+ if (!req->info)
+ return -EINVAL;
+
+ for (unit = 0; unit < ARRAY_SIZE(unit_size_map); unit++)
+ if (!(req->nbytes & (unit_size_map[unit].size - 1)))
+ break;
+
+ if ((unit_size_map[unit].value == CCP_XTS_AES_UNIT_SIZE__LAST) ||
+ (ctx->u.aes.key_len != AES_KEYSIZE_128)) {
+ /* Use the fallback to process the request for any
+ * unsupported unit sizes or key sizes
+ */
+ ablkcipher_request_set_tfm(req, ctx->u.aes.tfm_ablkcipher);
+ ret = (encrypt) ? crypto_ablkcipher_encrypt(req) :
+ crypto_ablkcipher_decrypt(req);
+ ablkcipher_request_set_tfm(req, __crypto_ablkcipher_cast(tfm));
+
+ return ret;
+ }
+
+ memcpy(rctx->iv, req->info, AES_BLOCK_SIZE);
+ sg_init_one(&rctx->iv_sg, rctx->iv, AES_BLOCK_SIZE);
+
+ memset(&rctx->cmd, 0, sizeof(rctx->cmd));
+ INIT_LIST_HEAD(&rctx->cmd.entry);
+ rctx->cmd.engine = CCP_ENGINE_XTS_AES_128;
+ rctx->cmd.u.xts.action = (encrypt) ? CCP_AES_ACTION_ENCRYPT
+ : CCP_AES_ACTION_DECRYPT;
+ rctx->cmd.u.xts.unit_size = unit_size_map[unit].value;
+ rctx->cmd.u.xts.key = &ctx->u.aes.key_sg;
+ rctx->cmd.u.xts.key_len = ctx->u.aes.key_len;
+ rctx->cmd.u.xts.iv = &rctx->iv_sg;
+ rctx->cmd.u.xts.iv_len = AES_BLOCK_SIZE;
+ rctx->cmd.u.xts.src = req->src;
+ rctx->cmd.u.xts.src_len = req->nbytes;
+ rctx->cmd.u.xts.dst = req->dst;
+
+ ret = ccp_crypto_enqueue_request(&req->base, &rctx->cmd);
+
+ return ret;
+}
+
+static int ccp_aes_xts_encrypt(struct ablkcipher_request *req)
+{
+ return ccp_aes_xts_crypt(req, 1);
+}
+
+static int ccp_aes_xts_decrypt(struct ablkcipher_request *req)
+{
+ return ccp_aes_xts_crypt(req, 0);
+}
+
+static int ccp_aes_xts_cra_init(struct crypto_tfm *tfm)
+{
+ struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
+ struct crypto_ablkcipher *fallback_tfm;
+
+ ctx->complete = ccp_aes_xts_complete;
+ ctx->u.aes.key_len = 0;
+
+ fallback_tfm = crypto_alloc_ablkcipher(crypto_tfm_alg_name(tfm), 0,
+ CRYPTO_ALG_ASYNC |
+ CRYPTO_ALG_NEED_FALLBACK);
+ if (IS_ERR(fallback_tfm)) {
+ pr_warn("could not load fallback driver %s\n",
+ crypto_tfm_alg_name(tfm));
+ return PTR_ERR(fallback_tfm);
+ }
+ ctx->u.aes.tfm_ablkcipher = fallback_tfm;
+
+ tfm->crt_ablkcipher.reqsize = sizeof(struct ccp_aes_req_ctx) +
+ fallback_tfm->base.crt_ablkcipher.reqsize;
+
+ return 0;
+}
+
+static void ccp_aes_xts_cra_exit(struct crypto_tfm *tfm)
+{
+ struct ccp_ctx *ctx = crypto_tfm_ctx(tfm);
+
+ if (ctx->u.aes.tfm_ablkcipher)
+ crypto_free_ablkcipher(ctx->u.aes.tfm_ablkcipher);
+ ctx->u.aes.tfm_ablkcipher = NULL;
+}
+
+static int ccp_register_aes_xts_alg(struct list_head *head,
+ const struct ccp_aes_xts_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);
+
+ alg = &ccp_alg->alg;
+
+ snprintf(alg->cra_name, CRYPTO_MAX_ALG_NAME, "%s", def->name);
+ snprintf(alg->cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s",
+ def->drv_name);
+ alg->cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC |
+ CRYPTO_ALG_KERN_DRIVER_ONLY |
+ CRYPTO_ALG_NEED_FALLBACK;
+ alg->cra_blocksize = AES_BLOCK_SIZE;
+ alg->cra_ctxsize = sizeof(struct ccp_ctx);
+ alg->cra_priority = CCP_CRA_PRIORITY;
+ alg->cra_type = &crypto_ablkcipher_type;
+ alg->cra_ablkcipher.setkey = ccp_aes_xts_setkey;
+ alg->cra_ablkcipher.encrypt = ccp_aes_xts_encrypt;
+ alg->cra_ablkcipher.decrypt = ccp_aes_xts_decrypt;
+ alg->cra_ablkcipher.min_keysize = AES_MIN_KEY_SIZE * 2;
+ alg->cra_ablkcipher.max_keysize = AES_MAX_KEY_SIZE * 2;
+ alg->cra_ablkcipher.ivsize = AES_BLOCK_SIZE;
+ alg->cra_init = ccp_aes_xts_cra_init;
+ alg->cra_exit = ccp_aes_xts_cra_exit;
+ alg->cra_module = THIS_MODULE;
+
+ 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_xts_algs(struct list_head *head)
+{
+ int i, ret;
+
+ for (i = 0; i < ARRAY_SIZE(aes_xts_algs); i++) {
+ ret = ccp_register_aes_xts_alg(head, &aes_xts_algs[i]);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
Code Review / kvmfornfv.git / blobdiff