arch/x86/crypto/morus1280_glue.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * The MORUS-1280 Authenticated-Encryption Algorithm
   4  *   Common x86 SIMD glue skeleton
   5  *
   6  * Copyright (c) 2016-2018 Ondrej Mosnacek <omosnacek@gmail.com>
   7  * Copyright (C) 2017-2018 Red Hat, Inc. All rights reserved.
   8  */
   9
  10 #include <crypto/internal/aead.h>
  11 #include <crypto/internal/skcipher.h>
  12 #include <crypto/morus1280_glue.h>
  13 #include <crypto/scatterwalk.h>
  14 #include <linux/err.h>
  15 #include <linux/init.h>
  16 #include <linux/kernel.h>
  17 #include <linux/module.h>
  18 #include <linux/scatterlist.h>
  19 #include <asm/fpu/api.h>
  20
  21 struct morus1280_state {
  22         struct morus1280_block s[MORUS_STATE_BLOCKS];
  23 };
  24
  25 struct morus1280_ops {
  26         int (*skcipher_walk_init)(struct skcipher_walk *walk,
  27                                   struct aead_request *req, bool atomic);
  28
  29         void (*crypt_blocks)(void *state, const void *src, void *dst,
  30                              unsigned int length);
  31         void (*crypt_tail)(void *state, const void *src, void *dst,
  32                            unsigned int length);
  33 };
  34
  35 static void crypto_morus1280_glue_process_ad(
  36                 struct morus1280_state *state,
  37                 const struct morus1280_glue_ops *ops,
  38                 struct scatterlist *sg_src, unsigned int assoclen)
  39 {
  40         struct scatter_walk walk;
  41         struct morus1280_block buf;
  42         unsigned int pos = 0;
  43
  44         scatterwalk_start(&walk, sg_src);
  45         while (assoclen != 0) {
  46                 unsigned int size = scatterwalk_clamp(&walk, assoclen);
  47                 unsigned int left = size;
  48                 void *mapped = scatterwalk_map(&walk);
  49                 const u8 *src = (const u8 *)mapped;
  50
  51                 if (pos + size >= MORUS1280_BLOCK_SIZE) {
  52                         if (pos > 0) {
  53                                 unsigned int fill = MORUS1280_BLOCK_SIZE - pos;
  54                                 memcpy(buf.bytes + pos, src, fill);
  55                                 ops->ad(state, buf.bytes, MORUS1280_BLOCK_SIZE);
  56                                 pos = 0;
  57                                 left -= fill;
  58                                 src += fill;
  59                         }
  60
  61                         ops->ad(state, src, left);
  62                         src += left & ~(MORUS1280_BLOCK_SIZE - 1);
  63                         left &= MORUS1280_BLOCK_SIZE - 1;
  64                 }
  65
  66                 memcpy(buf.bytes + pos, src, left);
  67
  68                 pos += left;
  69                 assoclen -= size;
  70                 scatterwalk_unmap(mapped);
  71                 scatterwalk_advance(&walk, size);
  72                 scatterwalk_done(&walk, 0, assoclen);
  73         }
  74
  75         if (pos > 0) {
  76                 memset(buf.bytes + pos, 0, MORUS1280_BLOCK_SIZE - pos);
  77                 ops->ad(state, buf.bytes, MORUS1280_BLOCK_SIZE);
  78         }
  79 }
  80
  81 static void crypto_morus1280_glue_process_crypt(struct morus1280_state *state,
  82                                                 struct morus1280_ops ops,
  83                                                 struct skcipher_walk *walk)
  84 {
  85         while (walk->nbytes >= MORUS1280_BLOCK_SIZE) {
  86                 ops.crypt_blocks(state, walk->src.virt.addr,
  87                                  walk->dst.virt.addr,
  88                                  round_down(walk->nbytes,
  89                                             MORUS1280_BLOCK_SIZE));
  90                 skcipher_walk_done(walk, walk->nbytes % MORUS1280_BLOCK_SIZE);
  91         }
  92
  93         if (walk->nbytes) {
  94                 ops.crypt_tail(state, walk->src.virt.addr, walk->dst.virt.addr,
  95                                walk->nbytes);
  96                 skcipher_walk_done(walk, 0);
  97         }
  98 }
  99
 100 int crypto_morus1280_glue_setkey(struct crypto_aead *aead, const u8 *key,
 101                                  unsigned int keylen)
 102 {
 103         struct morus1280_ctx *ctx = crypto_aead_ctx(aead);
 104
 105         if (keylen == MORUS1280_BLOCK_SIZE) {
 106                 memcpy(ctx->key.bytes, key, MORUS1280_BLOCK_SIZE);
 107         } else if (keylen == MORUS1280_BLOCK_SIZE / 2) {
 108                 memcpy(ctx->key.bytes, key, keylen);
 109                 memcpy(ctx->key.bytes + keylen, key, keylen);
 110         } else {
 111                 crypto_aead_set_flags(aead, CRYPTO_TFM_RES_BAD_KEY_LEN);
 112                 return -EINVAL;
 113         }
 114
 115         return 0;
 116 }
 117 EXPORT_SYMBOL_GPL(crypto_morus1280_glue_setkey);
 118
 119 int crypto_morus1280_glue_setauthsize(struct crypto_aead *tfm,
 120                                       unsigned int authsize)
 121 {
 122         return (authsize <= MORUS_MAX_AUTH_SIZE) ? 0 : -EINVAL;
 123 }
 124 EXPORT_SYMBOL_GPL(crypto_morus1280_glue_setauthsize);
 125
 126 static void crypto_morus1280_glue_crypt(struct aead_request *req,
 127                                         struct morus1280_ops ops,
 128                                         unsigned int cryptlen,
 129                                         struct morus1280_block *tag_xor)
 130 {
 131         struct crypto_aead *tfm = crypto_aead_reqtfm(req);
 132         struct morus1280_ctx *ctx = crypto_aead_ctx(tfm);
 133         struct morus1280_state state;
 134         struct skcipher_walk walk;
 135
 136         ops.skcipher_walk_init(&walk, req, true);
 137
 138         kernel_fpu_begin();
 139
 140         ctx->ops->init(&state, &ctx->key, req->iv);
 141         crypto_morus1280_glue_process_ad(&state, ctx->ops, req->src, req->assoclen);
 142         crypto_morus1280_glue_process_crypt(&state, ops, &walk);
 143         ctx->ops->final(&state, tag_xor, req->assoclen, cryptlen);
 144
 145         kernel_fpu_end();
 146 }
 147
 148 int crypto_morus1280_glue_encrypt(struct aead_request *req)
 149 {
 150         struct crypto_aead *tfm = crypto_aead_reqtfm(req);
 151         struct morus1280_ctx *ctx = crypto_aead_ctx(tfm);
 152         struct morus1280_ops OPS = {
 153                 .skcipher_walk_init = skcipher_walk_aead_encrypt,
 154                 .crypt_blocks = ctx->ops->enc,
 155                 .crypt_tail = ctx->ops->enc_tail,
 156         };
 157
 158         struct morus1280_block tag = {};
 159         unsigned int authsize = crypto_aead_authsize(tfm);
 160         unsigned int cryptlen = req->cryptlen;
 161
 162         crypto_morus1280_glue_crypt(req, OPS, cryptlen, &tag);
 163
 164         scatterwalk_map_and_copy(tag.bytes, req->dst,
 165                                  req->assoclen + cryptlen, authsize, 1);
 166         return 0;
 167 }
 168 EXPORT_SYMBOL_GPL(crypto_morus1280_glue_encrypt);
 169
 170 int crypto_morus1280_glue_decrypt(struct aead_request *req)
 171 {
 172         static const u8 zeros[MORUS1280_BLOCK_SIZE] = {};
 173
 174         struct crypto_aead *tfm = crypto_aead_reqtfm(req);
 175         struct morus1280_ctx *ctx = crypto_aead_ctx(tfm);
 176         struct morus1280_ops OPS = {
 177                 .skcipher_walk_init = skcipher_walk_aead_decrypt,
 178                 .crypt_blocks = ctx->ops->dec,
 179                 .crypt_tail = ctx->ops->dec_tail,
 180         };
 181
 182         struct morus1280_block tag;
 183         unsigned int authsize = crypto_aead_authsize(tfm);
 184         unsigned int cryptlen = req->cryptlen - authsize;
 185
 186         scatterwalk_map_and_copy(tag.bytes, req->src,
 187                                  req->assoclen + cryptlen, authsize, 0);
 188
 189         crypto_morus1280_glue_crypt(req, OPS, cryptlen, &tag);
 190
 191         return crypto_memneq(tag.bytes, zeros, authsize) ? -EBADMSG : 0;
 192 }
 193 EXPORT_SYMBOL_GPL(crypto_morus1280_glue_decrypt);
 194
 195 void crypto_morus1280_glue_init_ops(struct crypto_aead *aead,
 196                                     const struct morus1280_glue_ops *ops)
 197 {
 198         struct morus1280_ctx *ctx = crypto_aead_ctx(aead);
 199         ctx->ops = ops;
 200 }
 201 EXPORT_SYMBOL_GPL(crypto_morus1280_glue_init_ops);
 202
 203 MODULE_LICENSE("GPL");
 204 MODULE_AUTHOR("Ondrej Mosnacek <omosnacek@gmail.com>");
 205 MODULE_DESCRIPTION("MORUS-1280 AEAD mode -- glue for x86 optimizations");