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Subject[PATCH v2 11/17] powerpc: crypto: AES-XCBC mode routines for nx encryption
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Date
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>
---
drivers/crypto/nx/nx-aes-xcbc.c | 234 +++++++++++++++++++++++++++++++++++++++
1 files changed, 234 insertions(+), 0 deletions(-)
create mode 100644 drivers/crypto/nx/nx-aes-xcbc.c
diff --git a/drivers/crypto/nx/nx-aes-xcbc.c b/drivers/crypto/nx/nx-aes-xcbc.c
new file mode 100644
index 0000000..f0eadb1
--- /dev/null
+++ b/drivers/crypto/nx/nx-aes-xcbc.c
@@ -0,0 +1,234 @@
+/**
+ * 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);
+ 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);
+ 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,
+ }
+};
--
1.7.1



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