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Diffstat (limited to 'drivers/crypto/ccp/ccp-crypto-aes-xts.c')
-rw-r--r--drivers/crypto/ccp/ccp-crypto-aes-xts.c286
1 files changed, 286 insertions, 0 deletions
diff --git a/drivers/crypto/ccp/ccp-crypto-aes-xts.c b/drivers/crypto/ccp/ccp-crypto-aes-xts.c
new file mode 100644
index 000000000..6849261ca
--- /dev/null
+++ b/drivers/crypto/ccp/ccp-crypto-aes-xts.c
@@ -0,0 +1,286 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * AMD Cryptographic Coprocessor (CCP) AES XTS crypto API support
+ *
+ * Copyright (C) 2013,2017 Advanced Micro Devices, Inc.
+ *
+ * Author: Gary R Hook <gary.hook@amd.com>
+ * Author: Tom Lendacky <thomas.lendacky@amd.com>
+ */
+
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/delay.h>
+#include <linux/scatterlist.h>
+#include <crypto/aes.h>
+#include <crypto/xts.h>
+#include <crypto/internal/skcipher.h>
+#include <crypto/scatterwalk.h>
+
+#include "ccp-crypto.h"
+
+struct ccp_aes_xts_def {
+ const char *name;
+ const char *drv_name;
+};
+
+static const 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 xts_unit_sizes[] = {
+ {
+ .size = 16,
+ .value = CCP_XTS_AES_UNIT_SIZE_16,
+ },
+ {
+ .size = 512,
+ .value = CCP_XTS_AES_UNIT_SIZE_512,
+ },
+ {
+ .size = 1024,
+ .value = CCP_XTS_AES_UNIT_SIZE_1024,
+ },
+ {
+ .size = 2048,
+ .value = CCP_XTS_AES_UNIT_SIZE_2048,
+ },
+ {
+ .size = 4096,
+ .value = CCP_XTS_AES_UNIT_SIZE_4096,
+ },
+};
+
+static int ccp_aes_xts_complete(struct crypto_async_request *async_req, int ret)
+{
+ struct skcipher_request *req = skcipher_request_cast(async_req);
+ struct ccp_aes_req_ctx *rctx = skcipher_request_ctx(req);
+
+ if (ret)
+ return ret;
+
+ memcpy(req->iv, rctx->iv, AES_BLOCK_SIZE);
+
+ return 0;
+}
+
+static int ccp_aes_xts_setkey(struct crypto_skcipher *tfm, const u8 *key,
+ unsigned int key_len)
+{
+ struct ccp_ctx *ctx = crypto_skcipher_ctx(tfm);
+ unsigned int ccpversion = ccp_version();
+ int ret;
+
+ ret = xts_verify_key(tfm, key, key_len);
+ if (ret)
+ return ret;
+
+ /* Version 3 devices support 128-bit keys; version 5 devices can
+ * accommodate 128- and 256-bit keys.
+ */
+ switch (key_len) {
+ case AES_KEYSIZE_128 * 2:
+ memcpy(ctx->u.aes.key, key, key_len);
+ break;
+ case AES_KEYSIZE_256 * 2:
+ if (ccpversion > CCP_VERSION(3, 0))
+ 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_skcipher_setkey(ctx->u.aes.tfm_skcipher, key, key_len);
+}
+
+static int ccp_aes_xts_crypt(struct skcipher_request *req,
+ unsigned int encrypt)
+{
+ struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+ struct ccp_ctx *ctx = crypto_skcipher_ctx(tfm);
+ struct ccp_aes_req_ctx *rctx = skcipher_request_ctx(req);
+ unsigned int ccpversion = ccp_version();
+ unsigned int fallback = 0;
+ unsigned int unit;
+ u32 unit_size;
+ int ret;
+
+ if (!ctx->u.aes.key_len)
+ return -EINVAL;
+
+ if (!req->iv)
+ return -EINVAL;
+
+ /* Check conditions under which the CCP can fulfill a request. The
+ * device can handle input plaintext of a length that is a multiple
+ * of the unit_size, bug the crypto implementation only supports
+ * the unit_size being equal to the input length. This limits the
+ * number of scenarios we can handle.
+ */
+ unit_size = CCP_XTS_AES_UNIT_SIZE__LAST;
+ for (unit = 0; unit < ARRAY_SIZE(xts_unit_sizes); unit++) {
+ if (req->cryptlen == xts_unit_sizes[unit].size) {
+ unit_size = unit;
+ break;
+ }
+ }
+ /* The CCP has restrictions on block sizes. Also, a version 3 device
+ * only supports AES-128 operations; version 5 CCPs support both
+ * AES-128 and -256 operations.
+ */
+ if (unit_size == CCP_XTS_AES_UNIT_SIZE__LAST)
+ fallback = 1;
+ if ((ccpversion < CCP_VERSION(5, 0)) &&
+ (ctx->u.aes.key_len != AES_KEYSIZE_128))
+ fallback = 1;
+ if ((ctx->u.aes.key_len != AES_KEYSIZE_128) &&
+ (ctx->u.aes.key_len != AES_KEYSIZE_256))
+ fallback = 1;
+ if (fallback) {
+ /* Use the fallback to process the request for any
+ * unsupported unit sizes or key sizes
+ */
+ skcipher_request_set_tfm(&rctx->fallback_req,
+ ctx->u.aes.tfm_skcipher);
+ skcipher_request_set_callback(&rctx->fallback_req,
+ req->base.flags,
+ req->base.complete,
+ req->base.data);
+ skcipher_request_set_crypt(&rctx->fallback_req, req->src,
+ req->dst, req->cryptlen, req->iv);
+ ret = encrypt ? crypto_skcipher_encrypt(&rctx->fallback_req) :
+ crypto_skcipher_decrypt(&rctx->fallback_req);
+ return ret;
+ }
+
+ memcpy(rctx->iv, req->iv, 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.type = CCP_AES_TYPE_128;
+ rctx->cmd.u.xts.action = (encrypt) ? CCP_AES_ACTION_ENCRYPT
+ : CCP_AES_ACTION_DECRYPT;
+ rctx->cmd.u.xts.unit_size = unit_size;
+ 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->cryptlen;
+ 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 skcipher_request *req)
+{
+ return ccp_aes_xts_crypt(req, 1);
+}
+
+static int ccp_aes_xts_decrypt(struct skcipher_request *req)
+{
+ return ccp_aes_xts_crypt(req, 0);
+}
+
+static int ccp_aes_xts_init_tfm(struct crypto_skcipher *tfm)
+{
+ struct ccp_ctx *ctx = crypto_skcipher_ctx(tfm);
+ struct crypto_skcipher *fallback_tfm;
+
+ ctx->complete = ccp_aes_xts_complete;
+ ctx->u.aes.key_len = 0;
+
+ fallback_tfm = crypto_alloc_skcipher("xts(aes)", 0,
+ CRYPTO_ALG_NEED_FALLBACK);
+ if (IS_ERR(fallback_tfm)) {
+ pr_warn("could not load fallback driver xts(aes)\n");
+ return PTR_ERR(fallback_tfm);
+ }
+ ctx->u.aes.tfm_skcipher = fallback_tfm;
+
+ crypto_skcipher_set_reqsize(tfm, sizeof(struct ccp_aes_req_ctx) +
+ crypto_skcipher_reqsize(fallback_tfm));
+
+ return 0;
+}
+
+static void ccp_aes_xts_exit_tfm(struct crypto_skcipher *tfm)
+{
+ struct ccp_ctx *ctx = crypto_skcipher_ctx(tfm);
+
+ crypto_free_skcipher(ctx->u.aes.tfm_skcipher);
+}
+
+static int ccp_register_aes_xts_alg(struct list_head *head,
+ const struct ccp_aes_xts_def *def)
+{
+ struct ccp_crypto_skcipher_alg *ccp_alg;
+ struct skcipher_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->base.cra_name, CRYPTO_MAX_ALG_NAME, "%s", def->name);
+ snprintf(alg->base.cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s",
+ def->drv_name);
+ alg->base.cra_flags = CRYPTO_ALG_ASYNC |
+ CRYPTO_ALG_ALLOCATES_MEMORY |
+ CRYPTO_ALG_KERN_DRIVER_ONLY |
+ CRYPTO_ALG_NEED_FALLBACK;
+ alg->base.cra_blocksize = AES_BLOCK_SIZE;
+ alg->base.cra_ctxsize = sizeof(struct ccp_ctx);
+ alg->base.cra_priority = CCP_CRA_PRIORITY;
+ alg->base.cra_module = THIS_MODULE;
+
+ alg->setkey = ccp_aes_xts_setkey;
+ alg->encrypt = ccp_aes_xts_encrypt;
+ alg->decrypt = ccp_aes_xts_decrypt;
+ alg->min_keysize = AES_MIN_KEY_SIZE * 2;
+ alg->max_keysize = AES_MAX_KEY_SIZE * 2;
+ alg->ivsize = AES_BLOCK_SIZE;
+ alg->init = ccp_aes_xts_init_tfm;
+ alg->exit = ccp_aes_xts_exit_tfm;
+
+ ret = crypto_register_skcipher(alg);
+ if (ret) {
+ pr_err("%s skcipher algorithm registration error (%d)\n",
+ alg->base.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;
+}