nx-aes-ctr.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * AES CTR routines supporting the Power 7+ Nest Accelerators driver
  4 *
  5 * Copyright (C) 2011-2012 International Business Machines Inc.
  6 *
  7 * Author: Kent Yoder <yoder1@us.ibm.com>
  8 */
  9
 10#include <crypto/aes.h>
 11#include <crypto/ctr.h>
 12#include <crypto/internal/skcipher.h>
 13#include <linux/err.h>
 14#include <linux/kernel.h>
 15#include <linux/module.h>
 16#include <linux/spinlock.h>
 17#include <linux/string.h>
 18#include <asm/vio.h>
 19
 20#include "nx_csbcpb.h"
 21#include "nx.h"
 22
 23
 24static int ctr_aes_nx_set_key(struct crypto_skcipher *tfm,
 25			      const u8               *in_key,
 26			      unsigned int            key_len)
 27{
 28	struct nx_crypto_ctx *nx_ctx = crypto_skcipher_ctx(tfm);
 29	struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
 30
 31	nx_ctx_init(nx_ctx, HCOP_FC_AES);
 32
 33	switch (key_len) {
 34	case AES_KEYSIZE_128:
 35		NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_128);
 36		nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_128];
 37		break;
 38	case AES_KEYSIZE_192:
 39		NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_192);
 40		nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_192];
 41		break;
 42	case AES_KEYSIZE_256:
 43		NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_256);
 44		nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_256];
 45		break;
 46	default:
 47		return -EINVAL;
 48	}
 49
 50	csbcpb->cpb.hdr.mode = NX_MODE_AES_CTR;
 51	memcpy(csbcpb->cpb.aes_ctr.key, in_key, key_len);
 52
 53	return 0;
 54}
 55
 56static int ctr3686_aes_nx_set_key(struct crypto_skcipher *tfm,
 57				  const u8               *in_key,
 58				  unsigned int            key_len)
 59{
 60	struct nx_crypto_ctx *nx_ctx = crypto_skcipher_ctx(tfm);
 61
 62	if (key_len < CTR_RFC3686_NONCE_SIZE)
 63		return -EINVAL;
 64
 65	memcpy(nx_ctx->priv.ctr.nonce,
 66	       in_key + key_len - CTR_RFC3686_NONCE_SIZE,
 67	       CTR_RFC3686_NONCE_SIZE);
 68
 69	key_len -= CTR_RFC3686_NONCE_SIZE;
 70
 71	return ctr_aes_nx_set_key(tfm, in_key, key_len);
 72}
 73
 74static int ctr_aes_nx_crypt(struct skcipher_request *req, u8 *iv)
 75{
 76	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 77	struct nx_crypto_ctx *nx_ctx = crypto_skcipher_ctx(tfm);
 78	struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
 79	unsigned long irq_flags;
 80	unsigned int processed = 0, to_process;
 81	int rc;
 82
 83	spin_lock_irqsave(&nx_ctx->lock, irq_flags);
 84
 85	do {
 86		to_process = req->cryptlen - processed;
 87
 88		rc = nx_build_sg_lists(nx_ctx, iv, req->dst, req->src,
 89				       &to_process, processed,
 90				       csbcpb->cpb.aes_ctr.iv);
 91		if (rc)
 92			goto out;
 93
 94		if (!nx_ctx->op.inlen || !nx_ctx->op.outlen) {
 95			rc = -EINVAL;
 96			goto out;
 97		}
 98
 99		rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
100				   req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
101		if (rc)
102			goto out;
103
104		memcpy(iv, csbcpb->cpb.aes_cbc.cv, AES_BLOCK_SIZE);
105
106		atomic_inc(&(nx_ctx->stats->aes_ops));
107		atomic64_add(be32_to_cpu(csbcpb->csb.processed_byte_count),
108			     &(nx_ctx->stats->aes_bytes));
109
110		processed += to_process;
111	} while (processed < req->cryptlen);
112out:
113	spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
114	return rc;
115}
116
117static int ctr3686_aes_nx_crypt(struct skcipher_request *req)
118{
119	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
120	struct nx_crypto_ctx *nx_ctx = crypto_skcipher_ctx(tfm);
121	u8 iv[16];
122
123	memcpy(iv, nx_ctx->priv.ctr.nonce, CTR_RFC3686_NONCE_SIZE);
124	memcpy(iv + CTR_RFC3686_NONCE_SIZE, req->iv, CTR_RFC3686_IV_SIZE);
125	iv[12] = iv[13] = iv[14] = 0;
126	iv[15] = 1;
127
128	return ctr_aes_nx_crypt(req, iv);
129}
130
131struct skcipher_alg nx_ctr3686_aes_alg = {
132	.base.cra_name		= "rfc3686(ctr(aes))",
133	.base.cra_driver_name	= "rfc3686-ctr-aes-nx",
134	.base.cra_priority	= 300,
135	.base.cra_blocksize	= 1,
136	.base.cra_ctxsize	= sizeof(struct nx_crypto_ctx),
137	.base.cra_module	= THIS_MODULE,
138	.init			= nx_crypto_ctx_aes_ctr_init,
139	.exit			= nx_crypto_ctx_skcipher_exit,
140	.min_keysize		= AES_MIN_KEY_SIZE + CTR_RFC3686_NONCE_SIZE,
141	.max_keysize		= AES_MAX_KEY_SIZE + CTR_RFC3686_NONCE_SIZE,
142	.ivsize			= CTR_RFC3686_IV_SIZE,
143	.setkey			= ctr3686_aes_nx_set_key,
144	.encrypt		= ctr3686_aes_nx_crypt,
145	.decrypt		= ctr3686_aes_nx_crypt,
146	.chunksize		= AES_BLOCK_SIZE,
147};