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Subject[PATCH v3 08/17] powerpc: crypto: AES-CCM mode routines for nx encryption
From
Date
These routines add support for AES in CCM 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-ccm.c | 465 ++++++++++++++++++++++++++++++++++++++++
1 files changed, 465 insertions(+), 0 deletions(-)
create mode 100644 drivers/crypto/nx/nx-aes-ccm.c
diff --git a/drivers/crypto/nx/nx-aes-ccm.c b/drivers/crypto/nx/nx-aes-ccm.c
new file mode 100644
index 0000000..e418bef
--- /dev/null
+++ b/drivers/crypto/nx/nx-aes-ccm.c
@@ -0,0 +1,465 @@
+/**
+ * AES CCM 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 ccm_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:
+ NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_128);
+ NX_CPB_SET_KEY_SIZE(csbcpb_aead, NX_KS_AES_128);
+ nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_128];
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ csbcpb->cpb.hdr.mode = NX_MODE_AES_CCM;
+ memcpy(csbcpb->cpb.aes_ccm.key, in_key, key_len);
+
+ csbcpb_aead->cpb.hdr.mode = NX_MODE_AES_CCA;
+ memcpy(csbcpb_aead->cpb.aes_cca.key, in_key, key_len);
+
+ return 0;
+
+}
+
+static int ccm4309_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);
+
+ if (key_len < 3)
+ return -EINVAL;
+
+ key_len -= 3;
+
+ memcpy(nx_ctx->priv.ccm.nonce, in_key + key_len, 3);
+
+ return ccm_aes_nx_set_key(tfm, in_key, key_len);
+}
+
+static int ccm_aes_nx_setauthsize(struct crypto_aead *tfm,
+ unsigned int authsize)
+{
+ switch (authsize) {
+ case 4:
+ case 6:
+ case 8:
+ case 10:
+ case 12:
+ case 14:
+ case 16:
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ crypto_aead_crt(tfm)->authsize = authsize;
+
+ return 0;
+}
+
+static int ccm4309_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;
+}
+
+/* taken from crypto/ccm.c */
+static int set_msg_len(u8 *block, unsigned int msglen, int csize)
+{
+ __be32 data;
+
+ memset(block, 0, csize);
+ block += csize;
+
+ if (csize >= 4)
+ csize = 4;
+ else if (msglen > (unsigned int)(1 << (8 * csize)))
+ return -EOVERFLOW;
+
+ data = cpu_to_be32(msglen);
+ memcpy(block - csize, (u8 *)&data + 4 - csize, csize);
+
+ return 0;
+}
+
+/* taken from crypto/ccm.c */
+static inline int crypto_ccm_check_iv(const u8 *iv)
+{
+ /* 2 <= L <= 8, so 1 <= L' <= 7. */
+ if (1 > iv[0] || iv[0] > 7)
+ return -EINVAL;
+
+ return 0;
+}
+
+/* based on code from crypto/ccm.c */
+static int generate_b0(u8 *iv, unsigned int assoclen, unsigned int authsize,
+ unsigned int cryptlen, u8 *b0)
+{
+ unsigned int l, lp, m = authsize;
+ int rc;
+
+ memcpy(b0, iv, 16);
+
+ lp = b0[0];
+ l = lp + 1;
+
+ /* set m, bits 3-5 */
+ *b0 |= (8 * ((m - 2) / 2));
+
+ /* set adata, bit 6, if associated data is used */
+ if (assoclen)
+ *b0 |= 64;
+
+ rc = set_msg_len(b0 + 16 - l, cryptlen, l);
+
+ return rc;
+}
+
+static int generate_pat(u8 *iv,
+ struct aead_request *req,
+ struct nx_crypto_ctx *nx_ctx,
+ unsigned int authsize,
+ unsigned int nbytes,
+ u8 *out)
+{
+ struct nx_sg *nx_insg = nx_ctx->in_sg;
+ struct nx_sg *nx_outsg = nx_ctx->out_sg;
+ unsigned int iauth_len = 0;
+ struct vio_pfo_op *op = NULL;
+ u8 tmp[16], *b1 = NULL, *b0 = NULL, *result = NULL;
+ int rc;
+
+ /* zero the ctr value */
+ memset(iv + 15 - iv[0], 0, iv[0] + 1);
+
+ if (!req->assoclen) {
+ b0 = nx_ctx->csbcpb->cpb.aes_ccm.in_pat_or_b0;
+ } else if (req->assoclen <= 14) {
+ /* if associated data is 14 bytes or less, we do 1 GCM
+ * operation on 2 AES blocks, B0 (stored in the csbcpb) and B1,
+ * which is fed in through the source buffers here */
+ b0 = nx_ctx->csbcpb->cpb.aes_ccm.in_pat_or_b0;
+ b1 = nx_ctx->priv.ccm.iauth_tag;
+ iauth_len = req->assoclen;
+
+ nx_insg = nx_build_sg_list(nx_insg, b1, 16, nx_ctx->ap->sglen);
+ nx_outsg = nx_build_sg_list(nx_outsg, tmp, 16,
+ nx_ctx->ap->sglen);
+
+ /* inlen should be negative, indicating to phyp that its a
+ * pointer to an sg list */
+ nx_ctx->op.inlen = (nx_ctx->in_sg - nx_insg) *
+ sizeof(struct nx_sg);
+ nx_ctx->op.outlen = (nx_ctx->out_sg - nx_outsg) *
+ sizeof(struct nx_sg);
+
+ NX_CPB_FDM(nx_ctx->csbcpb) |= NX_FDM_ENDE_ENCRYPT;
+ NX_CPB_FDM(nx_ctx->csbcpb) |= NX_FDM_INTERMEDIATE;
+
+ op = &nx_ctx->op;
+ result = nx_ctx->csbcpb->cpb.aes_ccm.out_pat_or_mac;
+ } else if (req->assoclen <= 65280) {
+ /* if associated data is less than (2^16 - 2^8), we construct
+ * B1 differently and feed in the associated data to a CCA
+ * operation */
+ b0 = nx_ctx->csbcpb_aead->cpb.aes_cca.b0;
+ b1 = nx_ctx->csbcpb_aead->cpb.aes_cca.b1;
+ iauth_len = 14;
+
+ /* remaining assoc data must have scatterlist built for it */
+ nx_insg = nx_walk_and_build(nx_insg, nx_ctx->ap->sglen,
+ req->assoc, iauth_len,
+ req->assoclen - iauth_len);
+ nx_ctx->op_aead.inlen = (nx_ctx->in_sg - nx_insg) *
+ sizeof(struct nx_sg);
+
+ op = &nx_ctx->op_aead;
+ result = nx_ctx->csbcpb_aead->cpb.aes_cca.out_pat_or_b0;
+ } else {
+ /* if associated data is less than (2^32), we construct B1
+ * differently yet again and feed in the associated data to a
+ * CCA operation */
+ pr_err("associated data len is %u bytes (returning -EINVAL)\n",
+ req->assoclen);
+ rc = -EINVAL;
+ }
+
+ rc = generate_b0(iv, req->assoclen, authsize, nbytes, b0);
+ if (rc)
+ goto done;
+
+ if (b1) {
+ memset(b1, 0, 16);
+ *(u16 *)b1 = (u16)req->assoclen;
+
+ scatterwalk_map_and_copy(b1 + 2, req->assoc, 0,
+ iauth_len, SCATTERWALK_FROM_SG);
+
+ rc = nx_hcall_sync(nx_ctx, op);
+ if (rc)
+ goto done;
+
+ atomic_inc(&(nx_ctx->stats->aes_ops));
+ atomic64_add(req->assoclen, &(nx_ctx->stats->aes_bytes));
+
+ memcpy(out, result, AES_BLOCK_SIZE);
+ }
+done:
+ return rc;
+}
+
+static int ccm_nx_decrypt(struct aead_request *req,
+ struct blkcipher_desc *desc)
+{
+ struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm);
+ struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
+ unsigned int nbytes = req->cryptlen;
+ unsigned int authsize = crypto_aead_authsize(crypto_aead_reqtfm(req));
+ struct nx_ccm_priv *priv = &nx_ctx->priv.ccm;
+ int rc = -1;
+
+ if (nbytes > nx_ctx->ap->databytelen)
+ return -EINVAL;
+
+ nbytes -= authsize;
+
+ /* copy out the auth tag to compare with later */
+ scatterwalk_map_and_copy(priv->oauth_tag,
+ req->src, nbytes, authsize,
+ SCATTERWALK_FROM_SG);
+
+ rc = generate_pat(desc->info, req, nx_ctx, authsize, nbytes,
+ csbcpb->cpb.aes_ccm.in_pat_or_b0);
+ if (rc)
+ goto out;
+
+ rc = nx_build_sg_lists(nx_ctx, desc, req->dst, req->src, nbytes,
+ csbcpb->cpb.aes_ccm.iv_or_ctr);
+ if (rc)
+ goto out;
+
+ NX_CPB_FDM(nx_ctx->csbcpb) &= ~NX_FDM_ENDE_ENCRYPT;
+ NX_CPB_FDM(nx_ctx->csbcpb) &= ~NX_FDM_INTERMEDIATE;
+
+ 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));
+
+ rc = memcmp(csbcpb->cpb.aes_ccm.out_pat_or_mac, priv->oauth_tag,
+ authsize) ? -EBADMSG : 0;
+out:
+ return rc;
+}
+
+static int ccm_nx_encrypt(struct aead_request *req,
+ struct blkcipher_desc *desc)
+{
+ struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm);
+ struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
+ unsigned int nbytes = req->cryptlen;
+ unsigned int authsize = crypto_aead_authsize(crypto_aead_reqtfm(req));
+ int rc = -1;
+
+ if (nbytes > nx_ctx->ap->databytelen)
+ return -EINVAL;
+
+ rc = generate_pat(desc->info, req, nx_ctx, authsize, nbytes,
+ csbcpb->cpb.aes_ccm.in_pat_or_b0);
+ if (rc)
+ goto out;
+
+ rc = nx_build_sg_lists(nx_ctx, desc, req->dst, req->src, nbytes,
+ csbcpb->cpb.aes_ccm.iv_or_ctr);
+ if (rc)
+ goto out;
+
+ NX_CPB_FDM(csbcpb) |= NX_FDM_ENDE_ENCRYPT;
+ NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE;
+
+ 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));
+
+ /* copy out the auth tag */
+ scatterwalk_map_and_copy(csbcpb->cpb.aes_ccm.out_pat_or_mac,
+ req->dst, nbytes, authsize,
+ SCATTERWALK_TO_SG);
+out:
+ return rc;
+}
+
+static int ccm4309_aes_nx_encrypt(struct aead_request *req)
+{
+ struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm);
+ struct blkcipher_desc desc;
+ u8 *iv = nx_ctx->priv.ccm.iv;
+
+ iv[0] = 3;
+ memcpy(iv + 1, nx_ctx->priv.ccm.nonce, 3);
+ memcpy(iv + 4, req->iv, 8);
+
+ desc.info = iv;
+ desc.tfm = (struct crypto_blkcipher *)req->base.tfm;
+
+ return ccm_nx_encrypt(req, &desc);
+}
+
+static int ccm_aes_nx_encrypt(struct aead_request *req)
+{
+ struct blkcipher_desc desc;
+ int rc;
+
+ desc.info = req->iv;
+ desc.tfm = (struct crypto_blkcipher *)req->base.tfm;
+
+ rc = crypto_ccm_check_iv(desc.info);
+ if (rc)
+ return rc;
+
+ return ccm_nx_encrypt(req, &desc);
+}
+
+static int ccm4309_aes_nx_decrypt(struct aead_request *req)
+{
+ struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm);
+ struct blkcipher_desc desc;
+ u8 *iv = nx_ctx->priv.ccm.iv;
+
+ iv[0] = 3;
+ memcpy(iv + 1, nx_ctx->priv.ccm.nonce, 3);
+ memcpy(iv + 4, req->iv, 8);
+
+ desc.info = iv;
+ desc.tfm = (struct crypto_blkcipher *)req->base.tfm;
+
+ return ccm_nx_decrypt(req, &desc);
+}
+
+static int ccm_aes_nx_decrypt(struct aead_request *req)
+{
+ struct blkcipher_desc desc;
+ int rc;
+
+ desc.info = req->iv;
+ desc.tfm = (struct crypto_blkcipher *)req->base.tfm;
+
+ rc = crypto_ccm_check_iv(desc.info);
+ if (rc)
+ return rc;
+
+ return ccm_nx_decrypt(req, &desc);
+}
+
+/* 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_ccm_aes_alg = {
+ .cra_name = "ccm(aes)",
+ .cra_driver_name = "ccm-aes-nx",
+ .cra_priority = 300,
+ .cra_flags = CRYPTO_ALG_TYPE_AEAD |
+ CRYPTO_ALG_NEED_FALLBACK,
+ .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_ccm_aes_alg.cra_list),
+ .cra_init = nx_crypto_ctx_aes_ccm_init,
+ .cra_exit = nx_crypto_ctx_exit,
+ .cra_aead = {
+ .ivsize = AES_BLOCK_SIZE,
+ .maxauthsize = AES_BLOCK_SIZE,
+ .setkey = ccm_aes_nx_set_key,
+ .setauthsize = ccm_aes_nx_setauthsize,
+ .encrypt = ccm_aes_nx_encrypt,
+ .decrypt = ccm_aes_nx_decrypt,
+ }
+};
+
+struct crypto_alg nx_ccm4309_aes_alg = {
+ .cra_name = "rfc4309(ccm(aes))",
+ .cra_driver_name = "rfc4309-ccm-aes-nx",
+ .cra_priority = 300,
+ .cra_flags = CRYPTO_ALG_TYPE_AEAD |
+ CRYPTO_ALG_NEED_FALLBACK,
+ .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_ccm4309_aes_alg.cra_list),
+ .cra_init = nx_crypto_ctx_aes_ccm_init,
+ .cra_exit = nx_crypto_ctx_exit,
+ .cra_aead = {
+ .ivsize = 8,
+ .maxauthsize = AES_BLOCK_SIZE,
+ .setkey = ccm4309_aes_nx_set_key,
+ .setauthsize = ccm4309_aes_nx_setauthsize,
+ .encrypt = ccm4309_aes_nx_encrypt,
+ .decrypt = ccm4309_aes_nx_decrypt,
+ .geniv = "seqiv",
+ }
+};
--
1.7.1



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