arch/x86/crypto/morus640_glue.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * The MORUS-640 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/morus640_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 morus640_state {
  22         struct morus640_block s[MORUS_STATE_BLOCKS];
  23 };
  24
  25 struct morus640_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_morus640_glue_process_ad(
  36                 struct morus640_state *state,
  37                 const struct morus640_glue_ops *ops,
  38                 struct scatterlist *sg_src, unsigned int assoclen)
  39 {
  40         struct scatter_walk walk;
  41         struct morus640_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 >= MORUS640_BLOCK_SIZE) {
  52                         if (pos > 0) {
  53                                 unsigned int fill = MORUS640_BLOCK_SIZE - pos;
  54                                 memcpy(buf.bytes + pos, src, fill);
  55                                 ops->ad(state, buf.bytes, MORUS640_BLOCK_SIZE);
  56                                 pos = 0;
  57                                 left -= fill;
  58                                 src += fill;
  59                         }
  60
  61                         ops->ad(state, src, left);
  62                         src += left & ~(MORUS640_BLOCK_SIZE - 1);
  63                         left &= MORUS640_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, MORUS640_BLOCK_SIZE - pos);
  77                 ops->ad(state, buf.bytes, MORUS640_BLOCK_SIZE);
  78         }
  79 }
  80
  81 static void crypto_morus640_glue_process_crypt(struct morus640_state *state,
  82                                                struct morus640_ops ops,
  83                                                struct skcipher_walk *walk)
  84 {
  85         while (walk->nbytes >= MORUS640_BLOCK_SIZE) {
  86                 ops.crypt_blocks(state, walk->src.virt.addr,
  87                                  walk->dst.virt.addr,
  88                                  round_down(walk->nbytes, MORUS640_BLOCK_SIZE));
  89                 skcipher_walk_done(walk, walk->nbytes % MORUS640_BLOCK_SIZE);
  90         }
  91
  92         if (walk->nbytes) {
  93                 ops.crypt_tail(state, walk->src.virt.addr, walk->dst.virt.addr,
  94                                walk->nbytes);
  95                 skcipher_walk_done(walk, 0);
  96         }
  97 }
  98
  99 int crypto_morus640_glue_setkey(struct crypto_aead *aead, const u8 *key,
 100                                 unsigned int keylen)
 101 {
 102         struct morus640_ctx *ctx = crypto_aead_ctx(aead);
 103
 104         if (keylen != MORUS640_BLOCK_SIZE) {
 105                 crypto_aead_set_flags(aead, CRYPTO_TFM_RES_BAD_KEY_LEN);
 106                 return -EINVAL;
 107         }
 108
 109         memcpy(ctx->key.bytes, key, MORUS640_BLOCK_SIZE);
 110         return 0;
 111 }
 112 EXPORT_SYMBOL_GPL(crypto_morus640_glue_setkey);
 113
 114 int crypto_morus640_glue_setauthsize(struct crypto_aead *tfm,
 115                                      unsigned int authsize)
 116 {
 117         return (authsize <= MORUS_MAX_AUTH_SIZE) ? 0 : -EINVAL;
 118 }
 119 EXPORT_SYMBOL_GPL(crypto_morus640_glue_setauthsize);
 120
 121 static void crypto_morus640_glue_crypt(struct aead_request *req,
 122                                        struct morus640_ops ops,
 123                                        unsigned int cryptlen,
 124                                        struct morus640_block *tag_xor)
 125 {
 126         struct crypto_aead *tfm = crypto_aead_reqtfm(req);
 127         struct morus640_ctx *ctx = crypto_aead_ctx(tfm);
 128         struct morus640_state state;
 129         struct skcipher_walk walk;
 130
 131         ops.skcipher_walk_init(&walk, req, true);
 132
 133         kernel_fpu_begin();
 134
 135         ctx->ops->init(&state, &ctx->key, req->iv);
 136         crypto_morus640_glue_process_ad(&state, ctx->ops, req->src, req->assoclen);
 137         crypto_morus640_glue_process_crypt(&state, ops, &walk);
 138         ctx->ops->final(&state, tag_xor, req->assoclen, cryptlen);
 139
 140         kernel_fpu_end();
 141 }
 142
 143 int crypto_morus640_glue_encrypt(struct aead_request *req)
 144 {
 145         struct crypto_aead *tfm = crypto_aead_reqtfm(req);
 146         struct morus640_ctx *ctx = crypto_aead_ctx(tfm);
 147         struct morus640_ops OPS = {
 148                 .skcipher_walk_init = skcipher_walk_aead_encrypt,
 149                 .crypt_blocks = ctx->ops->enc,
 150                 .crypt_tail = ctx->ops->enc_tail,
 151         };
 152
 153         struct morus640_block tag = {};
 154         unsigned int authsize = crypto_aead_authsize(tfm);
 155         unsigned int cryptlen = req->cryptlen;
 156
 157         crypto_morus640_glue_crypt(req, OPS, cryptlen, &tag);
 158
 159         scatterwalk_map_and_copy(tag.bytes, req->dst,
 160                                  req->assoclen + cryptlen, authsize, 1);
 161         return 0;
 162 }
 163 EXPORT_SYMBOL_GPL(crypto_morus640_glue_encrypt);
 164
 165 int crypto_morus640_glue_decrypt(struct aead_request *req)
 166 {
 167         static const u8 zeros[MORUS640_BLOCK_SIZE] = {};
 168
 169         struct crypto_aead *tfm = crypto_aead_reqtfm(req);
 170         struct morus640_ctx *ctx = crypto_aead_ctx(tfm);
 171         struct morus640_ops OPS = {
 172                 .skcipher_walk_init = skcipher_walk_aead_decrypt,
 173                 .crypt_blocks = ctx->ops->dec,
 174                 .crypt_tail = ctx->ops->dec_tail,
 175         };
 176
 177         struct morus640_block tag;
 178         unsigned int authsize = crypto_aead_authsize(tfm);
 179         unsigned int cryptlen = req->cryptlen - authsize;
 180
 181         scatterwalk_map_and_copy(tag.bytes, req->src,
 182                                  req->assoclen + cryptlen, authsize, 0);
 183
 184         crypto_morus640_glue_crypt(req, OPS, cryptlen, &tag);
 185
 186         return crypto_memneq(tag.bytes, zeros, authsize) ? -EBADMSG : 0;
 187 }
 188 EXPORT_SYMBOL_GPL(crypto_morus640_glue_decrypt);
 189
 190 void crypto_morus640_glue_init_ops(struct crypto_aead *aead,
 191                                    const struct morus640_glue_ops *ops)
 192 {
 193         struct morus640_ctx *ctx = crypto_aead_ctx(aead);
 194         ctx->ops = ops;
 195 }
 196 EXPORT_SYMBOL_GPL(crypto_morus640_glue_init_ops);
 197
 198 MODULE_LICENSE("GPL");
 199 MODULE_AUTHOR("Ondrej Mosnacek <omosnacek@gmail.com>");
 200 MODULE_DESCRIPTION("MORUS-640 AEAD mode -- glue for x86 optimizations");