diff options
author | Kent Yoder <key@linux.vnet.ibm.com> | 2012-05-14 11:05:59 +0000 |
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committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2012-05-16 15:05:43 +1000 |
commit | f2a15f1d5d36004236dab8184593aa8eef3949ae (patch) | |
tree | 8ff9d2d7ff5e70e1eb593380f2809633bb8a0e9c /drivers/crypto/nx/nx-aes-gcm.c | |
parent | cc6250896a914f5604cbc3c0fbd2c5650972a7a6 (diff) | |
download | linux-f2a15f1d5d36004236dab8184593aa8eef3949ae.tar.bz2 |
powerpc/crypto: AES-GCM mode routines for nx encryption
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>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'drivers/crypto/nx/nx-aes-gcm.c')
-rw-r--r-- | drivers/crypto/nx/nx-aes-gcm.c | 353 |
1 files changed, 353 insertions, 0 deletions
diff --git a/drivers/crypto/nx/nx-aes-gcm.c b/drivers/crypto/nx/nx-aes-gcm.c new file mode 100644 index 000000000000..9ab1c7341dac --- /dev/null +++ b/drivers/crypto/nx/nx-aes-gcm.c @@ -0,0 +1,353 @@ +/** + * 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: + 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; + case AES_KEYSIZE_192: + NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_192); + NX_CPB_SET_KEY_SIZE(csbcpb_aead, NX_KS_AES_192); + nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_192]; + break; + case AES_KEYSIZE_256: + NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_256); + NX_CPB_SET_KEY_SIZE(csbcpb_aead, 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 aead_request *req, + u8 *out) +{ + struct nx_csbcpb *csbcpb_aead = nx_ctx->csbcpb_aead; + int rc = -EINVAL; + struct scatter_walk walk; + struct nx_sg *nx_sg = nx_ctx->in_sg; + + if (req->assoclen > nx_ctx->ap->databytelen) + goto out; + + if (req->assoclen <= AES_BLOCK_SIZE) { + scatterwalk_start(&walk, req->assoc); + scatterwalk_copychunks(out, &walk, req->assoclen, + SCATTERWALK_FROM_SG); + scatterwalk_done(&walk, SCATTERWALK_FROM_SG, 0); + + rc = 0; + goto out; + } + + nx_sg = nx_walk_and_build(nx_sg, nx_ctx->ap->sglen, req->assoc, 0, + req->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, + req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP); + if (rc) + goto out; + + atomic_inc(&(nx_ctx->stats->aes_ops)); + atomic64_add(req->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 = -EINVAL; + + if (nbytes > nx_ctx->ap->databytelen) + goto out; + + 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, + NX_CPB_KEY_SIZE(csbcpb) == NX_KS_AES_128 ? 16 : + NX_CPB_KEY_SIZE(csbcpb) == 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, csbcpb->cpb.aes_gcm.in_pat_or_aad); + if (rc) + goto out; + } + + if (enc) + NX_CPB_FDM(csbcpb) |= 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, + req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP); + 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, + } +}; |