/** * 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 */ #include #include #include #include #include #include #include #include #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_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_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, } };