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    Subject[PATCH v3 08/17] powerpc: crypto: AES-CCM mode routines for nx encryption
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    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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