These routines provide crypto API support for the CMAC mode of AES on the AMD CCP.
Signed-off-by: Tom Lendacky <thomas.lenda...@amd.com> --- drivers/crypto/ccp/ccp-crypto-aes-cmac.c | 355 ++++++++++++++++++++++++++++++ 1 file changed, 355 insertions(+) create mode 100644 drivers/crypto/ccp/ccp-crypto-aes-cmac.c diff --git a/drivers/crypto/ccp/ccp-crypto-aes-cmac.c b/drivers/crypto/ccp/ccp-crypto-aes-cmac.c new file mode 100644 index 0000000..5b9cd98 --- /dev/null +++ b/drivers/crypto/ccp/ccp-crypto-aes-cmac.c @@ -0,0 +1,355 @@ +/* + * AMD Cryptographic Coprocessor (CCP) AES CMAC crypto API support + * + * Copyright (C) 2013 Advanced Micro Devices, Inc. + * + * Author: Tom Lendacky <thomas.lenda...@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/hash.h> +#include <crypto/internal/hash.h> +#include <crypto/scatterwalk.h> + +#include "ccp-crypto.h" + + +static int ccp_aes_cmac_complete(struct crypto_async_request *async_req, + int ret) +{ + struct ahash_request *req = ahash_request_cast(async_req); + struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); + struct ccp_aes_cmac_req_ctx *rctx = ahash_request_ctx(req); + unsigned int digest_size = crypto_ahash_digestsize(tfm); + + if (ret) + goto e_free; + + if (rctx->hash_rem) { + /* Save remaining data to buffer */ + scatterwalk_map_and_copy(rctx->buf, rctx->cmd.u.aes.src, + rctx->hash_cnt, rctx->hash_rem, 0); + rctx->buf_count = rctx->hash_rem; + } else + rctx->buf_count = 0; + + memcpy(req->result, rctx->iv, digest_size); + +e_free: + sg_free_table(&rctx->data_sg); + + return ret; +} + +static int ccp_do_cmac_update(struct ahash_request *req, unsigned int nbytes, + unsigned int final) +{ + struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); + struct ccp_ctx *ctx = crypto_ahash_ctx(tfm); + struct ccp_aes_cmac_req_ctx *rctx = ahash_request_ctx(req); + struct scatterlist *sg, *cmac_key_sg = NULL; + unsigned int block_size = + crypto_tfm_alg_blocksize(crypto_ahash_tfm(tfm)); + unsigned int len, need_pad, sg_count; + int ret; + + if (!ctx->u.aes.key_len) { + pr_err("AES key not set\n"); + return -EINVAL; + } + + if (nbytes) + rctx->null_msg = 0; + + if (!final && ((nbytes + rctx->buf_count) <= block_size)) { + scatterwalk_map_and_copy(rctx->buf + rctx->buf_count, req->src, + 0, nbytes, 0); + rctx->buf_count += nbytes; + + return 0; + } + + len = rctx->buf_count + nbytes; + + rctx->final = final; + rctx->hash_cnt = final ? len : len & ~(block_size - 1); + rctx->hash_rem = final ? 0 : len & (block_size - 1); + if (!final && (rctx->hash_cnt == len)) { + /* CCP can't do zero length final, so keep some data around */ + rctx->hash_cnt -= block_size; + rctx->hash_rem = block_size; + } + + if (final && (rctx->null_msg || (len & (block_size - 1)))) + need_pad = 1; + else + need_pad = 0; + + sg_init_one(&rctx->iv_sg, rctx->iv, sizeof(rctx->iv)); + + /* Build the data scatterlist table - allocate enough entries for all + * possible data pieces (buffer, input data, padding) + */ + sg_count = (nbytes) ? sg_nents(req->src) + 2 : 2; + ret = sg_alloc_table(&rctx->data_sg, sg_count, GFP_KERNEL); + if (ret) + return ret; + + sg = NULL; + if (rctx->buf_count) { + sg_init_one(&rctx->buf_sg, rctx->buf, rctx->buf_count); + sg = ccp_crypto_sg_table_add(&rctx->data_sg, &rctx->buf_sg); + } + + if (nbytes) + sg = ccp_crypto_sg_table_add(&rctx->data_sg, req->src); + + if (need_pad) { + int pad_length = block_size - (len & (block_size - 1)); + + rctx->hash_cnt += pad_length; + + memset(rctx->pad, 0, sizeof(rctx->pad)); + rctx->pad[0] = 0x80; + sg_init_one(&rctx->pad_sg, rctx->pad, pad_length); + sg = ccp_crypto_sg_table_add(&rctx->data_sg, &rctx->pad_sg); + } + if (sg) + sg_mark_end(sg); + + /* Initialize the K1/K2 scatterlist */ + if (final) + cmac_key_sg = (need_pad) ? &ctx->u.aes.k2_sg + : &ctx->u.aes.k1_sg; + + 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 = CCP_AES_ACTION_ENCRYPT; + 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 = &rctx->iv_sg; + rctx->cmd.u.aes.iv_len = AES_BLOCK_SIZE; + rctx->cmd.u.aes.src = (sg) ? rctx->data_sg.sgl : NULL; + rctx->cmd.u.aes.src_len = rctx->hash_cnt; + rctx->cmd.u.aes.dst = NULL; + rctx->cmd.u.aes.cmac_key = cmac_key_sg; + rctx->cmd.u.aes.cmac_key_len = ctx->u.aes.kn_len; + rctx->cmd.u.aes.cmac_final = final; + + ret = ccp_crypto_enqueue_request(&req->base, &rctx->cmd); + + return ret; +} + +static int ccp_aes_cmac_init(struct ahash_request *req) +{ + struct ccp_aes_cmac_req_ctx *rctx = ahash_request_ctx(req); + + memset(rctx, 0, sizeof(*rctx)); + + rctx->null_msg = 1; + + return 0; +} + +static int ccp_aes_cmac_update(struct ahash_request *req) +{ + return ccp_do_cmac_update(req, req->nbytes, 0); +} + +static int ccp_aes_cmac_final(struct ahash_request *req) +{ + return ccp_do_cmac_update(req, 0, 1); +} + +static int ccp_aes_cmac_finup(struct ahash_request *req) +{ + return ccp_do_cmac_update(req, req->nbytes, 1); +} + +static int ccp_aes_cmac_digest(struct ahash_request *req) +{ + int ret; + + ret = ccp_aes_cmac_init(req); + if (ret) + return ret; + + return ccp_do_cmac_update(req, req->nbytes, 1); +} + +static int ccp_aes_cmac_setkey(struct crypto_ahash *tfm, const u8 *key, + unsigned int key_len) +{ + struct ccp_ctx *ctx = crypto_tfm_ctx(crypto_ahash_tfm(tfm)); + struct ccp_crypto_ahash_alg *alg = + ccp_crypto_ahash_alg(crypto_ahash_tfm(tfm)); + u64 k0_hi, k0_lo, k1_hi, k1_lo, k2_hi, k2_lo; + u64 rb_hi = 0x00, rb_lo = 0x87; + __be64 *gk; + int ret; + + 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_ahash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN); + return -EINVAL; + } + ctx->u.aes.mode = alg->mode; + + /* Set to zero until complete */ + ctx->u.aes.key_len = 0; + + /* Set the key for the AES cipher used to generate the keys */ + ret = crypto_cipher_setkey(ctx->u.aes.tfm_cipher, key, key_len); + if (ret) + return ret; + + /* Encrypt a block of zeroes - use key area in context */ + memset(ctx->u.aes.key, 0, sizeof(ctx->u.aes.key)); + crypto_cipher_encrypt_one(ctx->u.aes.tfm_cipher, ctx->u.aes.key, + ctx->u.aes.key); + + /* Generate K1 and K2 */ + k0_hi = be64_to_cpu(*((__be64 *)ctx->u.aes.key)); + k0_lo = be64_to_cpu(*((__be64 *)ctx->u.aes.key + 1)); + + k1_hi = (k0_hi << 1) | (k0_lo >> 63); + k1_lo = k0_lo << 1; + if (ctx->u.aes.key[0] & 0x80) { + k1_hi ^= rb_hi; + k1_lo ^= rb_lo; + } + gk = (__be64 *)ctx->u.aes.k1; + *gk = cpu_to_be64(k1_hi); + gk++; + *gk = cpu_to_be64(k1_lo); + + k2_hi = (k1_hi << 1) | (k1_lo >> 63); + k2_lo = k1_lo << 1; + if (ctx->u.aes.k1[0] & 0x80) { + k2_hi ^= rb_hi; + k2_lo ^= rb_lo; + } + gk = (__be64 *)ctx->u.aes.k2; + *gk = cpu_to_be64(k2_hi); + gk++; + *gk = cpu_to_be64(k2_lo); + + ctx->u.aes.kn_len = sizeof(ctx->u.aes.k1); + sg_init_one(&ctx->u.aes.k1_sg, ctx->u.aes.k1, sizeof(ctx->u.aes.k1)); + sg_init_one(&ctx->u.aes.k2_sg, ctx->u.aes.k2, sizeof(ctx->u.aes.k2)); + + /* Save the supplied key */ + memset(ctx->u.aes.key, 0, sizeof(ctx->u.aes.key)); + memcpy(ctx->u.aes.key, key, key_len); + ctx->u.aes.key_len = key_len; + sg_init_one(&ctx->u.aes.key_sg, ctx->u.aes.key, key_len); + + return ret; +} + +static int ccp_aes_cmac_cra_init(struct crypto_tfm *tfm) +{ + struct ccp_ctx *ctx = crypto_tfm_ctx(tfm); + struct crypto_ahash *ahash = __crypto_ahash_cast(tfm); + struct crypto_cipher *cipher_tfm; + + ctx->complete = ccp_aes_cmac_complete; + ctx->u.aes.key_len = 0; + + crypto_ahash_set_reqsize(ahash, sizeof(struct ccp_aes_cmac_req_ctx)); + + cipher_tfm = crypto_alloc_cipher("aes", 0, + CRYPTO_ALG_ASYNC | CRYPTO_ALG_NEED_FALLBACK); + if (IS_ERR(cipher_tfm)) { + pr_warn("could not load aes cipher driver\n"); + return PTR_ERR(cipher_tfm); + } + ctx->u.aes.tfm_cipher = cipher_tfm; + + return 0; +} + +static void ccp_aes_cmac_cra_exit(struct crypto_tfm *tfm) +{ + struct ccp_ctx *ctx = crypto_tfm_ctx(tfm); + + if (ctx->u.aes.tfm_cipher) + crypto_free_cipher(ctx->u.aes.tfm_cipher); + ctx->u.aes.tfm_cipher = NULL; +} + +int ccp_register_aes_cmac_algs(struct list_head *head) +{ + struct ccp_crypto_ahash_alg *ccp_alg; + struct ahash_alg *alg; + struct hash_alg_common *halg; + struct crypto_alg *base; + int ret; + + ccp_alg = kzalloc(sizeof(*ccp_alg), GFP_KERNEL); + if (!ccp_alg) + return -ENOMEM; + + INIT_LIST_HEAD(&ccp_alg->entry); + ccp_alg->mode = CCP_AES_MODE_CMAC; + + alg = &ccp_alg->alg; + alg->init = ccp_aes_cmac_init; + alg->update = ccp_aes_cmac_update; + alg->final = ccp_aes_cmac_final; + alg->finup = ccp_aes_cmac_finup; + alg->digest = ccp_aes_cmac_digest; + alg->setkey = ccp_aes_cmac_setkey; + + halg = &alg->halg; + halg->digestsize = AES_BLOCK_SIZE; + + base = &halg->base; + snprintf(base->cra_name, CRYPTO_MAX_ALG_NAME, "cmac(aes)"); + snprintf(base->cra_driver_name, CRYPTO_MAX_ALG_NAME, "cmac-aes-ccp"); + base->cra_flags = CRYPTO_ALG_TYPE_AHASH | CRYPTO_ALG_ASYNC | + CRYPTO_ALG_KERN_DRIVER_ONLY | + CRYPTO_ALG_NEED_FALLBACK; + base->cra_blocksize = AES_BLOCK_SIZE; + base->cra_ctxsize = sizeof(struct ccp_ctx); + base->cra_priority = CCP_CRA_PRIORITY; + base->cra_type = &crypto_ahash_type; + base->cra_init = ccp_aes_cmac_cra_init; + base->cra_exit = ccp_aes_cmac_cra_exit; + base->cra_module = THIS_MODULE; + + ret = crypto_register_ahash(alg); + if (ret) { + pr_err("%s ahash algorithm registration error (%d)\n", + base->cra_name, ret); + kfree(ccp_alg); + return ret; + } + + list_add(&ccp_alg->entry, head); + + return 0; +} -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/