| // 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 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 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 crypto_tfm *xfm = crypto_ablkcipher_tfm(tfm); |
| struct ccp_ctx *ctx = crypto_tfm_ctx(xfm); |
| unsigned int ccpversion = ccp_version(); |
| int ret; |
| |
| ret = xts_check_key(xfm, 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_sync_skcipher_setkey(ctx->u.aes.tfm_skcipher, key, key_len); |
| } |
| |
| static int ccp_aes_xts_crypt(struct ablkcipher_request *req, |
| unsigned int encrypt) |
| { |
| struct ccp_ctx *ctx = crypto_tfm_ctx(req->base.tfm); |
| struct ccp_aes_req_ctx *rctx = ablkcipher_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->info) |
| 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->nbytes == 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) { |
| SYNC_SKCIPHER_REQUEST_ON_STACK(subreq, |
| ctx->u.aes.tfm_skcipher); |
| |
| /* Use the fallback to process the request for any |
| * unsupported unit sizes or key sizes |
| */ |
| skcipher_request_set_sync_tfm(subreq, ctx->u.aes.tfm_skcipher); |
| skcipher_request_set_callback(subreq, req->base.flags, |
| NULL, NULL); |
| skcipher_request_set_crypt(subreq, req->src, req->dst, |
| req->nbytes, req->info); |
| ret = encrypt ? crypto_skcipher_encrypt(subreq) : |
| crypto_skcipher_decrypt(subreq); |
| skcipher_request_zero(subreq); |
| 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.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->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_sync_skcipher *fallback_tfm; |
| |
| ctx->complete = ccp_aes_xts_complete; |
| ctx->u.aes.key_len = 0; |
| |
| fallback_tfm = crypto_alloc_sync_skcipher("xts(aes)", 0, |
| CRYPTO_ALG_ASYNC | |
| 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; |
| |
| tfm->crt_ablkcipher.reqsize = sizeof(struct ccp_aes_req_ctx); |
| |
| return 0; |
| } |
| |
| static void ccp_aes_xts_cra_exit(struct crypto_tfm *tfm) |
| { |
| struct ccp_ctx *ctx = crypto_tfm_ctx(tfm); |
| |
| crypto_free_sync_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_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; |
| } |