drivers/crypto/nx/nx-aes-ctr.c

   1 /**
   2  * AES CTR routines supporting the Power 7+ Nest Accelerators driver
   3  *
   4  * Copyright (C) 2011-2012 International Business Machines Inc.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; version 2 only.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18  *
  19  * Author: Kent Yoder <yoder1@us.ibm.com>
  20  */
  21
  22 #include <crypto/aes.h>
  23 #include <crypto/ctr.h>
  24 #include <crypto/algapi.h>
  25 #include <linux/module.h>
  26 #include <linux/types.h>
  27 #include <linux/crypto.h>
  28 #include <asm/vio.h>
  29
  30 #include "nx_csbcpb.h"
  31 #include "nx.h"
  32
  33
  34 static int ctr_aes_nx_set_key(struct crypto_tfm *tfm,
  35                               const u8          *in_key,
  36                               unsigned int       key_len)
  37 {
  38         struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(tfm);
  39         struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
  40
  41         nx_ctx_init(nx_ctx, HCOP_FC_AES);
  42
  43         switch (key_len) {
  44         case AES_KEYSIZE_128:
  45                 NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_128);
  46                 nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_128];
  47                 break;
  48         case AES_KEYSIZE_192:
  49                 NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_192);
  50                 nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_192];
  51                 break;
  52         case AES_KEYSIZE_256:
  53                 NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_256);
  54                 nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_256];
  55                 break;
  56         default:
  57                 return -EINVAL;
  58         }
  59
  60         csbcpb->cpb.hdr.mode = NX_MODE_AES_CTR;
  61         memcpy(csbcpb->cpb.aes_ctr.key, in_key, key_len);
  62
  63         return 0;
  64 }
  65
  66 static int ctr3686_aes_nx_set_key(struct crypto_tfm *tfm,
  67                                   const u8          *in_key,
  68                                   unsigned int       key_len)
  69 {
  70         struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(tfm);
  71
  72         if (key_len < CTR_RFC3686_NONCE_SIZE)
  73                 return -EINVAL;
  74
  75         memcpy(nx_ctx->priv.ctr.nonce,
  76                in_key + key_len - CTR_RFC3686_NONCE_SIZE,
  77                CTR_RFC3686_NONCE_SIZE);
  78
  79         key_len -= CTR_RFC3686_NONCE_SIZE;
  80
  81         return ctr_aes_nx_set_key(tfm, in_key, key_len);
  82 }
  83
  84 static int ctr_aes_nx_crypt(struct blkcipher_desc *desc,
  85                             struct scatterlist    *dst,
  86                             struct scatterlist    *src,
  87                             unsigned int           nbytes)
  88 {
  89         struct nx_crypto_ctx *nx_ctx = crypto_blkcipher_ctx(desc->tfm);
  90         struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
  91         unsigned long irq_flags;
  92         unsigned int processed = 0, to_process;
  93         int rc;
  94
  95         spin_lock_irqsave(&nx_ctx->lock, irq_flags);
  96
  97         do {
  98                 to_process = nbytes - processed;
  99
 100                 rc = nx_build_sg_lists(nx_ctx, desc, dst, src, &to_process,
 101                                        processed, csbcpb->cpb.aes_ctr.iv);
 102                 if (rc)
 103                         goto out;
 104
 105                 if (!nx_ctx->op.inlen || !nx_ctx->op.outlen) {
 106                         rc = -EINVAL;
 107                         goto out;
 108                 }
 109
 110                 rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
 111                                    desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP);
 112                 if (rc)
 113                         goto out;
 114
 115                 memcpy(desc->info, csbcpb->cpb.aes_cbc.cv, AES_BLOCK_SIZE);
 116
 117                 atomic_inc(&(nx_ctx->stats->aes_ops));
 118                 atomic64_add(csbcpb->csb.processed_byte_count,
 119                              &(nx_ctx->stats->aes_bytes));
 120
 121                 processed += to_process;
 122         } while (processed < nbytes);
 123 out:
 124         spin_unlock_irqrestore(&nx_ctx->lock, irq_flags);
 125         return rc;
 126 }
 127
 128 static int ctr3686_aes_nx_crypt(struct blkcipher_desc *desc,
 129                                 struct scatterlist    *dst,
 130                                 struct scatterlist    *src,
 131                                 unsigned int           nbytes)
 132 {
 133         struct nx_crypto_ctx *nx_ctx = crypto_blkcipher_ctx(desc->tfm);
 134         u8 iv[16];
 135
 136         memcpy(iv, nx_ctx->priv.ctr.nonce, CTR_RFC3686_IV_SIZE);
 137         memcpy(iv + CTR_RFC3686_NONCE_SIZE,
 138                desc->info, CTR_RFC3686_IV_SIZE);
 139         iv[12] = iv[13] = iv[14] = 0;
 140         iv[15] = 1;
 141
 142         desc->info = iv;
 143
 144         return ctr_aes_nx_crypt(desc, dst, src, nbytes);
 145 }
 146
 147 struct crypto_alg nx_ctr3686_aes_alg = {
 148         .cra_name        = "rfc3686(ctr(aes))",
 149         .cra_driver_name = "rfc3686-ctr-aes-nx",
 150         .cra_priority    = 300,
 151         .cra_flags       = CRYPTO_ALG_TYPE_BLKCIPHER,
 152         .cra_blocksize   = 1,
 153         .cra_ctxsize     = sizeof(struct nx_crypto_ctx),
 154         .cra_type        = &crypto_blkcipher_type,
 155         .cra_module      = THIS_MODULE,
 156         .cra_init        = nx_crypto_ctx_aes_ctr_init,
 157         .cra_exit        = nx_crypto_ctx_exit,
 158         .cra_blkcipher = {
 159                 .min_keysize = AES_MIN_KEY_SIZE + CTR_RFC3686_NONCE_SIZE,
 160                 .max_keysize = AES_MAX_KEY_SIZE + CTR_RFC3686_NONCE_SIZE,
 161                 .ivsize      = CTR_RFC3686_IV_SIZE,
 162                 .geniv       = "seqiv",
 163                 .setkey      = ctr3686_aes_nx_set_key,
 164                 .encrypt     = ctr3686_aes_nx_crypt,
 165                 .decrypt     = ctr3686_aes_nx_crypt,
 166         }
 167 };