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linux-next/drivers/crypto/nx/nx-aes-xcbc.c
Kent Yoder 6148c1ad6d powerpc/crypto: AES-XCBC mode routines for nx encryption
These routines add support for AES in XCBC mode on the Power7+ CPU's
in-Nest accelerator driver.

Signed-off-by: Kent Yoder <key@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-05-16 15:05:43 +10:00

237 lines
6.9 KiB
C

/**
* AES XCBC routines supporting the Power 7+ Nest Accelerators driver
*
* Copyright (C) 2011-2012 International Business Machines Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 only.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* Author: Kent Yoder <yoder1@us.ibm.com>
*/
#include <crypto/internal/hash.h>
#include <crypto/aes.h>
#include <crypto/algapi.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/crypto.h>
#include <asm/vio.h>
#include "nx_csbcpb.h"
#include "nx.h"
struct xcbc_state {
u8 state[AES_BLOCK_SIZE];
unsigned int count;
u8 buffer[AES_BLOCK_SIZE];
};
static int nx_xcbc_set_key(struct crypto_shash *desc,
const u8 *in_key,
unsigned int key_len)
{
struct nx_crypto_ctx *nx_ctx = crypto_shash_ctx(desc);
switch (key_len) {
case AES_KEYSIZE_128:
nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_128];
break;
default:
return -EINVAL;
}
memcpy(nx_ctx->priv.xcbc.key, in_key, key_len);
return 0;
}
static int nx_xcbc_init(struct shash_desc *desc)
{
struct xcbc_state *sctx = shash_desc_ctx(desc);
struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&desc->tfm->base);
struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
struct nx_sg *out_sg;
nx_ctx_init(nx_ctx, HCOP_FC_AES);
memset(sctx, 0, sizeof *sctx);
NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_128);
csbcpb->cpb.hdr.mode = NX_MODE_AES_XCBC_MAC;
memcpy(csbcpb->cpb.aes_xcbc.key, nx_ctx->priv.xcbc.key, AES_BLOCK_SIZE);
memset(nx_ctx->priv.xcbc.key, 0, sizeof *nx_ctx->priv.xcbc.key);
out_sg = nx_build_sg_list(nx_ctx->out_sg, (u8 *)sctx->state,
AES_BLOCK_SIZE, nx_ctx->ap->sglen);
nx_ctx->op.outlen = (nx_ctx->out_sg - out_sg) * sizeof(struct nx_sg);
return 0;
}
static int nx_xcbc_update(struct shash_desc *desc,
const u8 *data,
unsigned int len)
{
struct xcbc_state *sctx = shash_desc_ctx(desc);
struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&desc->tfm->base);
struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
struct nx_sg *in_sg;
u32 to_process, leftover;
int rc = 0;
if (NX_CPB_FDM(csbcpb) & NX_FDM_CONTINUATION) {
/* we've hit the nx chip previously and we're updating again,
* so copy over the partial digest */
memcpy(csbcpb->cpb.aes_xcbc.cv,
csbcpb->cpb.aes_xcbc.out_cv_mac, AES_BLOCK_SIZE);
}
/* 2 cases for total data len:
* 1: <= AES_BLOCK_SIZE: copy into state, return 0
* 2: > AES_BLOCK_SIZE: process X blocks, copy in leftover
*/
if (len + sctx->count <= AES_BLOCK_SIZE) {
memcpy(sctx->buffer + sctx->count, data, len);
sctx->count += len;
goto out;
}
/* to_process: the AES_BLOCK_SIZE data chunk to process in this
* update */
to_process = (sctx->count + len) & ~(AES_BLOCK_SIZE - 1);
leftover = (sctx->count + len) & (AES_BLOCK_SIZE - 1);
/* the hardware will not accept a 0 byte operation for this algorithm
* and the operation MUST be finalized to be correct. So if we happen
* to get an update that falls on a block sized boundary, we must
* save off the last block to finalize with later. */
if (!leftover) {
to_process -= AES_BLOCK_SIZE;
leftover = AES_BLOCK_SIZE;
}
if (sctx->count) {
in_sg = nx_build_sg_list(nx_ctx->in_sg, sctx->buffer,
sctx->count, nx_ctx->ap->sglen);
in_sg = nx_build_sg_list(in_sg, (u8 *)data,
to_process - sctx->count,
nx_ctx->ap->sglen);
nx_ctx->op.inlen = (nx_ctx->in_sg - in_sg) *
sizeof(struct nx_sg);
} else {
in_sg = nx_build_sg_list(nx_ctx->in_sg, (u8 *)data, to_process,
nx_ctx->ap->sglen);
nx_ctx->op.inlen = (nx_ctx->in_sg - in_sg) *
sizeof(struct nx_sg);
}
NX_CPB_FDM(csbcpb) |= NX_FDM_INTERMEDIATE;
if (!nx_ctx->op.inlen || !nx_ctx->op.outlen) {
rc = -EINVAL;
goto out;
}
rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP);
if (rc)
goto out;
atomic_inc(&(nx_ctx->stats->aes_ops));
/* copy the leftover back into the state struct */
memcpy(sctx->buffer, data + len - leftover, leftover);
sctx->count = leftover;
/* everything after the first update is continuation */
NX_CPB_FDM(csbcpb) |= NX_FDM_CONTINUATION;
out:
return rc;
}
static int nx_xcbc_final(struct shash_desc *desc, u8 *out)
{
struct xcbc_state *sctx = shash_desc_ctx(desc);
struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&desc->tfm->base);
struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
struct nx_sg *in_sg, *out_sg;
int rc = 0;
if (NX_CPB_FDM(csbcpb) & NX_FDM_CONTINUATION) {
/* we've hit the nx chip previously, now we're finalizing,
* so copy over the partial digest */
memcpy(csbcpb->cpb.aes_xcbc.cv,
csbcpb->cpb.aes_xcbc.out_cv_mac, AES_BLOCK_SIZE);
} else if (sctx->count == 0) {
/* we've never seen an update, so this is a 0 byte op. The
* hardware cannot handle a 0 byte op, so just copy out the
* known 0 byte result. This is cheaper than allocating a
* software context to do a 0 byte op */
u8 data[] = { 0x75, 0xf0, 0x25, 0x1d, 0x52, 0x8a, 0xc0, 0x1c,
0x45, 0x73, 0xdf, 0xd5, 0x84, 0xd7, 0x9f, 0x29 };
memcpy(out, data, sizeof(data));
goto out;
}
/* final is represented by continuing the operation and indicating that
* this is not an intermediate operation */
NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE;
in_sg = nx_build_sg_list(nx_ctx->in_sg, (u8 *)sctx->buffer,
sctx->count, nx_ctx->ap->sglen);
out_sg = nx_build_sg_list(nx_ctx->out_sg, out, AES_BLOCK_SIZE,
nx_ctx->ap->sglen);
nx_ctx->op.inlen = (nx_ctx->in_sg - in_sg) * sizeof(struct nx_sg);
nx_ctx->op.outlen = (nx_ctx->out_sg - out_sg) * sizeof(struct nx_sg);
if (!nx_ctx->op.outlen) {
rc = -EINVAL;
goto out;
}
rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP);
if (rc)
goto out;
atomic_inc(&(nx_ctx->stats->aes_ops));
memcpy(out, csbcpb->cpb.aes_xcbc.out_cv_mac, AES_BLOCK_SIZE);
out:
return rc;
}
struct shash_alg nx_shash_aes_xcbc_alg = {
.digestsize = AES_BLOCK_SIZE,
.init = nx_xcbc_init,
.update = nx_xcbc_update,
.final = nx_xcbc_final,
.setkey = nx_xcbc_set_key,
.descsize = sizeof(struct xcbc_state),
.statesize = sizeof(struct xcbc_state),
.base = {
.cra_name = "xcbc(aes)",
.cra_driver_name = "xcbc-aes-nx",
.cra_priority = 300,
.cra_flags = CRYPTO_ALG_TYPE_SHASH,
.cra_blocksize = AES_BLOCK_SIZE,
.cra_module = THIS_MODULE,
.cra_ctxsize = sizeof(struct nx_crypto_ctx),
.cra_init = nx_crypto_ctx_aes_xcbc_init,
.cra_exit = nx_crypto_ctx_exit,
}
};