diff options
| -rw-r--r-- | drivers/crypto/ccp/ccp-crypto-aes-xts.c | 285 |
1 files changed, 285 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 000000000000..d100b48415b6 --- /dev/null +++ b/drivers/crypto/ccp/ccp-crypto-aes-xts.c @@ -0,0 +1,285 @@ +/* + * 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) { + pr_err("AES key not set\n"); + return -EINVAL; + } + + if (req->nbytes & (AES_BLOCK_SIZE - 1)) { + pr_err("AES request size is not a multiple of the block size\n"); + return -EINVAL; + } + + if (!req->info) { + pr_err("AES IV not supplied"); + 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(tfm->__crt_alg->cra_name, 0, + CRYPTO_ALG_ASYNC | + CRYPTO_ALG_NEED_FALLBACK); + if (IS_ERR(fallback_tfm)) { + pr_warn("could not load fallback driver %s\n", + tfm->__crt_alg->cra_name); + 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; +} |
