--- /dev/null
+/*
+ * AMD Cryptographic Coprocessor (CCP) AES CMAC 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/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;
+}
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