blob: 8e162ad820857a4d6ed221c10b327642fd72dfd2 [file] [log] [blame]
/*
* 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 */
unsigned int offset = rctx->nbytes - rctx->hash_rem;
scatterwalk_map_and_copy(rctx->buf, rctx->src,
offset, rctx->hash_rem, 0);
rctx->buf_count = rctx->hash_rem;
} else
rctx->buf_count = 0;
/* Update result area if supplied */
if (req->result)
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 need_pad, sg_count;
gfp_t gfp;
u64 len;
int ret;
if (!ctx->u.aes.key_len)
return -EINVAL;
if (nbytes)
rctx->null_msg = 0;
len = (u64)rctx->buf_count + (u64)nbytes;
if (!final && (len <= block_size)) {
scatterwalk_map_and_copy(rctx->buf + rctx->buf_count, req->src,
0, nbytes, 0);
rctx->buf_count += nbytes;
return 0;
}
rctx->src = req->src;
rctx->nbytes = nbytes;
rctx->final = final;
rctx->hash_rem = final ? 0 : len & (block_size - 1);
rctx->hash_cnt = len - rctx->hash_rem;
if (!final && !rctx->hash_rem) {
/* 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;
gfp = req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ?
GFP_KERNEL : GFP_ATOMIC;
ret = sg_alloc_table(&rctx->data_sg, sg_count, gfp);
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);
sg = rctx->data_sg.sgl;
}
/* 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->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_aes_cmac_finup(req);
}
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;
}