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Subject[PATCH 10/17] powerpc: crypto: AES-GCM mode routines for nx encryption
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These routines add support for AES in GCM mode on the Power7+ CPU's
in-Nest accelerator driver.

Signed-off-by: Kent Yoder <key@linux.vnet.ibm.com>
---
arch/powerpc/crypto/nx/nx-aes-gcm.c | 352 +++++++++++++++++++++++++++++++++++
1 files changed, 352 insertions(+), 0 deletions(-)
create mode 100644 arch/powerpc/crypto/nx/nx-aes-gcm.c
diff --git a/arch/powerpc/crypto/nx/nx-aes-gcm.c b/arch/powerpc/crypto/nx/nx-aes-gcm.c
new file mode 100644
index 0000000..c336ef4
--- /dev/null
+++ b/arch/powerpc/crypto/nx/nx-aes-gcm.c
@@ -0,0 +1,352 @@
+/**
+ * AES GCM routines supporting the Power 7+ Nest Accelerators driver
+ *
+ * Copyright (C) 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/aead.h>
+#include <crypto/aes.h>
+#include <crypto/algapi.h>
+#include <crypto/scatterwalk.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/crypto.h>
+#include <asm/vio.h>
+
+#include "nx_csbcpb.h"
+#include "nx.h"
+
+
+static int gcm_aes_nx_set_key(struct crypto_aead *tfm,
+ const u8 *in_key,
+ unsigned int key_len)
+{
+ struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&tfm->base);
+ struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
+ struct nx_csbcpb *csbcpb_aead = nx_ctx->csbcpb_aead;
+
+ nx_ctx_init(nx_ctx, HCOP_FC_AES);
+
+ switch (key_len) {
+ case AES_KEYSIZE_128:
+ csbcpb->cpb.hdr.key_size = NX_KS_AES_128;
+ csbcpb_aead->cpb.hdr.key_size = NX_KS_AES_128;
+ nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_128];
+ break;
+ case AES_KEYSIZE_192:
+ csbcpb->cpb.hdr.key_size = NX_KS_AES_192;
+ csbcpb_aead->cpb.hdr.key_size = NX_KS_AES_192;
+ nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_192];
+ break;
+ case AES_KEYSIZE_256:
+ csbcpb->cpb.hdr.key_size = NX_KS_AES_256;
+ csbcpb_aead->cpb.hdr.key_size = NX_KS_AES_256;
+ nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_256];
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ csbcpb->cpb.hdr.mode = NX_MODE_AES_GCM;
+ memcpy(csbcpb->cpb.aes_gcm.key, in_key, key_len);
+
+ csbcpb_aead->cpb.hdr.mode = NX_MODE_AES_GCA;
+ memcpy(csbcpb_aead->cpb.aes_gca.key, in_key, key_len);
+
+ return 0;
+}
+
+static int gcm4106_aes_nx_set_key(struct crypto_aead *tfm,
+ const u8 *in_key,
+ unsigned int key_len)
+{
+ struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&tfm->base);
+ char *nonce = nx_ctx->priv.gcm.nonce;
+ int rc;
+
+ if (key_len < 4)
+ return -EINVAL;
+
+ key_len -= 4;
+
+ rc = gcm_aes_nx_set_key(tfm, in_key, key_len);
+ if (rc)
+ goto out;
+
+ memcpy(nonce, in_key + key_len, 4);
+out:
+ return rc;
+}
+
+static int gcm_aes_nx_setauthsize(struct crypto_aead *tfm,
+ unsigned int authsize)
+{
+ if (authsize > crypto_aead_alg(tfm)->maxauthsize)
+ return -EINVAL;
+
+ crypto_aead_crt(tfm)->authsize = authsize;
+
+ return 0;
+}
+
+static int gcm4106_aes_nx_setauthsize(struct crypto_aead *tfm,
+ unsigned int authsize)
+{
+ switch (authsize) {
+ case 8:
+ case 12:
+ case 16:
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ crypto_aead_crt(tfm)->authsize = authsize;
+
+ return 0;
+}
+
+static int nx_gca(struct nx_crypto_ctx *nx_ctx,
+ struct scatterlist *assoc,
+ unsigned int assoclen,
+ u8 *out)
+{
+ struct nx_csbcpb *csbcpb_aead = nx_ctx->csbcpb_aead;
+ int rc;
+ struct scatter_walk walk;
+ struct nx_sg *nx_sg = nx_ctx->in_sg;
+
+ if (assoclen > nx_ctx->ap->databytelen)
+ return -EINVAL;
+
+ if (assoclen <= AES_BLOCK_SIZE) {
+ scatterwalk_start(&walk, assoc);
+ scatterwalk_copychunks(out, &walk, assoclen,
+ SCATTERWALK_FROM_SG);
+ scatterwalk_done(&walk, SCATTERWALK_FROM_SG, 0);
+
+ return 0;
+ }
+
+ nx_sg = nx_walk_and_build(nx_sg, nx_ctx->ap->sglen, assoc, 0,
+ assoclen);
+ nx_ctx->op_aead.inlen = (nx_ctx->in_sg - nx_sg) * sizeof(struct nx_sg);
+
+ rc = nx_hcall_sync(nx_ctx, &nx_ctx->op_aead);
+ if (rc)
+ goto out;
+
+ atomic_inc(&(nx_ctx->stats->aes_ops));
+ atomic64_add(assoclen, &(nx_ctx->stats->aes_bytes));
+
+ memcpy(out, csbcpb_aead->cpb.aes_gca.out_pat, AES_BLOCK_SIZE);
+out:
+ return rc;
+}
+
+static int gcm_aes_nx_crypt(struct aead_request *req, int enc)
+{
+ struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm);
+ struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
+ struct blkcipher_desc desc;
+ unsigned int nbytes = req->cryptlen;
+ int rc = -1;
+
+ if (nbytes > nx_ctx->ap->databytelen)
+ return -EINVAL;
+
+ desc.info = nx_ctx->priv.gcm.iv;
+ /* initialize the counter */
+ *(u32 *)(desc.info + NX_GCM_CTR_OFFSET) = 1;
+
+ /* For scenarios where the input message is zero length, AES CTR mode
+ * may be used. Set the source data to be a single block (16B) of all
+ * zeros, and set the input IV value to be the same as the GMAC IV
+ * value. - nx_wb 4.8.1.3 */
+ if (nbytes == 0) {
+ char src[AES_BLOCK_SIZE] = {};
+ struct scatterlist sg;
+
+ desc.tfm = crypto_alloc_blkcipher("ctr(aes)", 0, 0);
+ if (IS_ERR(desc.tfm)) {
+ rc = -ENOMEM;
+ goto out;
+ }
+
+ crypto_blkcipher_setkey(desc.tfm, csbcpb->cpb.aes_gcm.key,
+ csbcpb->cpb.hdr.key_size == NX_KS_AES_128 ? 16 :
+ csbcpb->cpb.hdr.key_size == NX_KS_AES_192 ? 24 : 32);
+
+ sg_init_one(&sg, src, AES_BLOCK_SIZE);
+ if (enc)
+ crypto_blkcipher_encrypt_iv(&desc, req->dst, &sg,
+ AES_BLOCK_SIZE);
+ else
+ crypto_blkcipher_decrypt_iv(&desc, req->dst, &sg,
+ AES_BLOCK_SIZE);
+ crypto_free_blkcipher(desc.tfm);
+
+ rc = 0;
+ goto out;
+ }
+
+ desc.tfm = (struct crypto_blkcipher *)req->base.tfm;
+
+ csbcpb->cpb.aes_gcm.bit_length_aad = req->assoclen * 8;
+
+ if (req->assoclen) {
+ rc = nx_gca(nx_ctx, req->assoc, req->assoclen,
+ csbcpb->cpb.aes_gcm.in_pat_or_aad);
+ if (rc)
+ goto out;
+ }
+
+ if (enc)
+ csbcpb->cpb.hdr.fdm.ende = NX_FDM_ENDE_ENCRYPT;
+ else
+ nbytes -= AES_BLOCK_SIZE;
+
+ csbcpb->cpb.aes_gcm.bit_length_data = nbytes * 8;
+
+ rc = nx_build_sg_lists(nx_ctx, &desc, req->dst, req->src, nbytes,
+ csbcpb->cpb.aes_gcm.iv_or_cnt);
+ if (rc)
+ goto out;
+
+ rc = nx_hcall_sync(nx_ctx, &nx_ctx->op);
+ if (rc)
+ goto out;
+
+ atomic_inc(&(nx_ctx->stats->aes_ops));
+ atomic64_add(csbcpb->csb.processed_byte_count,
+ &(nx_ctx->stats->aes_bytes));
+
+ if (enc) {
+ /* copy out the auth tag */
+ scatterwalk_map_and_copy(csbcpb->cpb.aes_gcm.out_pat_or_mac,
+ req->dst, nbytes,
+ crypto_aead_authsize(crypto_aead_reqtfm(req)),
+ SCATTERWALK_TO_SG);
+ } else if (req->assoclen) {
+ u8 *itag = nx_ctx->priv.gcm.iauth_tag;
+ u8 *otag = csbcpb->cpb.aes_gcm.out_pat_or_mac;
+
+ scatterwalk_map_and_copy(itag, req->dst, nbytes,
+ crypto_aead_authsize(crypto_aead_reqtfm(req)),
+ SCATTERWALK_FROM_SG);
+ rc = memcmp(itag, otag,
+ crypto_aead_authsize(crypto_aead_reqtfm(req))) ?
+ -EBADMSG : 0;
+ }
+out:
+ return rc;
+}
+
+static int gcm_aes_nx_encrypt(struct aead_request *req)
+{
+ struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm);
+ char *iv = nx_ctx->priv.gcm.iv;
+
+ memcpy(iv, req->iv, 12);
+
+ return gcm_aes_nx_crypt(req, 1);
+}
+
+static int gcm_aes_nx_decrypt(struct aead_request *req)
+{
+ struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm);
+ char *iv = nx_ctx->priv.gcm.iv;
+
+ memcpy(iv, req->iv, 12);
+
+ return gcm_aes_nx_crypt(req, 0);
+}
+
+static int gcm4106_aes_nx_encrypt(struct aead_request *req)
+{
+ struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm);
+ char *iv = nx_ctx->priv.gcm.iv;
+ char *nonce = nx_ctx->priv.gcm.nonce;
+
+ memcpy(iv, nonce, NX_GCM4106_NONCE_LEN);
+ memcpy(iv + NX_GCM4106_NONCE_LEN, req->iv, 8);
+
+ return gcm_aes_nx_crypt(req, 1);
+}
+
+static int gcm4106_aes_nx_decrypt(struct aead_request *req)
+{
+ struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm);
+ char *iv = nx_ctx->priv.gcm.iv;
+ char *nonce = nx_ctx->priv.gcm.nonce;
+
+ memcpy(iv, nonce, NX_GCM4106_NONCE_LEN);
+ memcpy(iv + NX_GCM4106_NONCE_LEN, req->iv, 8);
+
+ return gcm_aes_nx_crypt(req, 0);
+}
+
+/* tell the block cipher walk routines that this is a stream cipher by
+ * setting cra_blocksize to 1. Even using blkcipher_walk_virt_block
+ * during encrypt/decrypt doesn't solve this problem, because it calls
+ * blkcipher_walk_done under the covers, which doesn't use walk->blocksize,
+ * but instead uses this tfm->blocksize. */
+struct crypto_alg nx_gcm_aes_alg = {
+ .cra_name = "gcm(aes)",
+ .cra_driver_name = "gcm-aes-nx",
+ .cra_priority = 300,
+ .cra_flags = CRYPTO_ALG_TYPE_AEAD,
+ .cra_blocksize = 1,
+ .cra_ctxsize = sizeof(struct nx_crypto_ctx),
+ .cra_type = &crypto_aead_type,
+ .cra_module = THIS_MODULE,
+ .cra_list = LIST_HEAD_INIT(nx_gcm_aes_alg.cra_list),
+ .cra_init = nx_crypto_ctx_aes_gcm_init,
+ .cra_exit = nx_crypto_ctx_exit,
+ .cra_aead = {
+ .ivsize = AES_BLOCK_SIZE,
+ .maxauthsize = AES_BLOCK_SIZE,
+ .setkey = gcm_aes_nx_set_key,
+ .setauthsize = gcm_aes_nx_setauthsize,
+ .encrypt = gcm_aes_nx_encrypt,
+ .decrypt = gcm_aes_nx_decrypt,
+ }
+};
+
+struct crypto_alg nx_gcm4106_aes_alg = {
+ .cra_name = "rfc4106(gcm(aes))",
+ .cra_driver_name = "rfc4106-gcm-aes-nx",
+ .cra_priority = 300,
+ .cra_flags = CRYPTO_ALG_TYPE_AEAD,
+ .cra_blocksize = 1,
+ .cra_ctxsize = sizeof(struct nx_crypto_ctx),
+ .cra_type = &crypto_nivaead_type,
+ .cra_module = THIS_MODULE,
+ .cra_list = LIST_HEAD_INIT(nx_gcm4106_aes_alg.cra_list),
+ .cra_init = nx_crypto_ctx_aes_gcm_init,
+ .cra_exit = nx_crypto_ctx_exit,
+ .cra_aead = {
+ .ivsize = 8,
+ .maxauthsize = AES_BLOCK_SIZE,
+ .geniv = "seqiv",
+ .setkey = gcm4106_aes_nx_set_key,
+ .setauthsize = gcm4106_aes_nx_setauthsize,
+ .encrypt = gcm4106_aes_nx_encrypt,
+ .decrypt = gcm4106_aes_nx_decrypt,
+ }
+};
--
1.7.1



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