arch/x86/crypto/morus640_glue.c

   1 /*
   2  * The MORUS-640 Authenticated-Encryption Algorithm
   3  *   Common x86 SIMD glue skeleton
   4  *
   5  * Copyright (c) 2016-2018 Ondrej Mosnacek <omosnacek@gmail.com>
   6  * Copyright (C) 2017-2018 Red Hat, Inc. All rights reserved.
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU General Public License as published by the Free
  10  * Software Foundation; either version 2 of the License, or (at your option)
  11  * any later version.
  12  */
  13
  14 #include <crypto/internal/aead.h>
  15 #include <crypto/internal/skcipher.h>
  16 #include <crypto/morus640_glue.h>
  17 #include <crypto/scatterwalk.h>
  18 #include <linux/err.h>
  19 #include <linux/init.h>
  20 #include <linux/kernel.h>
  21 #include <linux/module.h>
  22 #include <linux/scatterlist.h>
  23 #include <asm/fpu/api.h>
  24
  25 struct morus640_state {
  26         struct morus640_block s[MORUS_STATE_BLOCKS];
  27 };
  28
  29 struct morus640_ops {
  30         int (*skcipher_walk_init)(struct skcipher_walk *walk,
  31                                   struct aead_request *req, bool atomic);
  32
  33         void (*crypt_blocks)(void *state, const void *src, void *dst,
  34                              unsigned int length);
  35         void (*crypt_tail)(void *state, const void *src, void *dst,
  36                            unsigned int length);
  37 };
  38
  39 static void crypto_morus640_glue_process_ad(
  40                 struct morus640_state *state,
  41                 const struct morus640_glue_ops *ops,
  42                 struct scatterlist *sg_src, unsigned int assoclen)
  43 {
  44         struct scatter_walk walk;
  45         struct morus640_block buf;
  46         unsigned int pos = 0;
  47
  48         scatterwalk_start(&walk, sg_src);
  49         while (assoclen != 0) {
  50                 unsigned int size = scatterwalk_clamp(&walk, assoclen);
  51                 unsigned int left = size;
  52                 void *mapped = scatterwalk_map(&walk);
  53                 const u8 *src = (const u8 *)mapped;
  54
  55                 if (pos + size >= MORUS640_BLOCK_SIZE) {
  56                         if (pos > 0) {
  57                                 unsigned int fill = MORUS640_BLOCK_SIZE - pos;
  58                                 memcpy(buf.bytes + pos, src, fill);
  59                                 ops->ad(state, buf.bytes, MORUS640_BLOCK_SIZE);
  60                                 pos = 0;
  61                                 left -= fill;
  62                                 src += fill;
  63                         }
  64
  65                         ops->ad(state, src, left);
  66                         src += left & ~(MORUS640_BLOCK_SIZE - 1);
  67                         left &= MORUS640_BLOCK_SIZE - 1;
  68                 }
  69
  70                 memcpy(buf.bytes + pos, src, left);
  71
  72                 pos += left;
  73                 assoclen -= size;
  74                 scatterwalk_unmap(mapped);
  75                 scatterwalk_advance(&walk, size);
  76                 scatterwalk_done(&walk, 0, assoclen);
  77         }
  78
  79         if (pos > 0) {
  80                 memset(buf.bytes + pos, 0, MORUS640_BLOCK_SIZE - pos);
  81                 ops->ad(state, buf.bytes, MORUS640_BLOCK_SIZE);
  82         }
  83 }
  84
  85 static void crypto_morus640_glue_process_crypt(struct morus640_state *state,
  86                                                struct morus640_ops ops,
  87                                                struct skcipher_walk *walk)
  88 {
  89         while (walk->nbytes >= MORUS640_BLOCK_SIZE) {
  90                 ops.crypt_blocks(state, walk->src.virt.addr,
  91                                  walk->dst.virt.addr,
  92                                  round_down(walk->nbytes, MORUS640_BLOCK_SIZE));
  93                 skcipher_walk_done(walk, walk->nbytes % MORUS640_BLOCK_SIZE);
  94         }
  95
  96         if (walk->nbytes) {
  97                 ops.crypt_tail(state, walk->src.virt.addr, walk->dst.virt.addr,
  98                                walk->nbytes);
  99                 skcipher_walk_done(walk, 0);
 100         }
 101 }
 102
 103 int crypto_morus640_glue_setkey(struct crypto_aead *aead, const u8 *key,
 104                                 unsigned int keylen)
 105 {
 106         struct morus640_ctx *ctx = crypto_aead_ctx(aead);
 107
 108         if (keylen != MORUS640_BLOCK_SIZE) {
 109                 crypto_aead_set_flags(aead, CRYPTO_TFM_RES_BAD_KEY_LEN);
 110                 return -EINVAL;
 111         }
 112
 113         memcpy(ctx->key.bytes, key, MORUS640_BLOCK_SIZE);
 114         return 0;
 115 }
 116 EXPORT_SYMBOL_GPL(crypto_morus640_glue_setkey);
 117
 118 int crypto_morus640_glue_setauthsize(struct crypto_aead *tfm,
 119                                      unsigned int authsize)
 120 {
 121         return (authsize <= MORUS_MAX_AUTH_SIZE) ? 0 : -EINVAL;
 122 }
 123 EXPORT_SYMBOL_GPL(crypto_morus640_glue_setauthsize);
 124
 125 static void crypto_morus640_glue_crypt(struct aead_request *req,
 126                                        struct morus640_ops ops,
 127                                        unsigned int cryptlen,
 128                                        struct morus640_block *tag_xor)
 129 {
 130         struct crypto_aead *tfm = crypto_aead_reqtfm(req);
 131         struct morus640_ctx *ctx = crypto_aead_ctx(tfm);
 132         struct morus640_state state;
 133         struct skcipher_walk walk;
 134
 135         ops.skcipher_walk_init(&walk, req, true);
 136
 137         kernel_fpu_begin();
 138
 139         ctx->ops->init(&state, &ctx->key, req->iv);
 140         crypto_morus640_glue_process_ad(&state, ctx->ops, req->src, req->assoclen);
 141         crypto_morus640_glue_process_crypt(&state, ops, &walk);
 142         ctx->ops->final(&state, tag_xor, req->assoclen, cryptlen);
 143
 144         kernel_fpu_end();
 145 }
 146
 147 int crypto_morus640_glue_encrypt(struct aead_request *req)
 148 {
 149         struct crypto_aead *tfm = crypto_aead_reqtfm(req);
 150         struct morus640_ctx *ctx = crypto_aead_ctx(tfm);
 151         struct morus640_ops OPS = {
 152                 .skcipher_walk_init = skcipher_walk_aead_encrypt,
 153                 .crypt_blocks = ctx->ops->enc,
 154                 .crypt_tail = ctx->ops->enc_tail,
 155         };
 156
 157         struct morus640_block tag = {};
 158         unsigned int authsize = crypto_aead_authsize(tfm);
 159         unsigned int cryptlen = req->cryptlen;
 160
 161         crypto_morus640_glue_crypt(req, OPS, cryptlen, &tag);
 162
 163         scatterwalk_map_and_copy(tag.bytes, req->dst,
 164                                  req->assoclen + cryptlen, authsize, 1);
 165         return 0;
 166 }
 167 EXPORT_SYMBOL_GPL(crypto_morus640_glue_encrypt);
 168
 169 int crypto_morus640_glue_decrypt(struct aead_request *req)
 170 {
 171         static const u8 zeros[MORUS640_BLOCK_SIZE] = {};
 172
 173         struct crypto_aead *tfm = crypto_aead_reqtfm(req);
 174         struct morus640_ctx *ctx = crypto_aead_ctx(tfm);
 175         struct morus640_ops OPS = {
 176                 .skcipher_walk_init = skcipher_walk_aead_decrypt,
 177                 .crypt_blocks = ctx->ops->dec,
 178                 .crypt_tail = ctx->ops->dec_tail,
 179         };
 180
 181         struct morus640_block tag;
 182         unsigned int authsize = crypto_aead_authsize(tfm);
 183         unsigned int cryptlen = req->cryptlen - authsize;
 184
 185         scatterwalk_map_and_copy(tag.bytes, req->src,
 186                                  req->assoclen + cryptlen, authsize, 0);
 187
 188         crypto_morus640_glue_crypt(req, OPS, cryptlen, &tag);
 189
 190         return crypto_memneq(tag.bytes, zeros, authsize) ? -EBADMSG : 0;
 191 }
 192 EXPORT_SYMBOL_GPL(crypto_morus640_glue_decrypt);
 193
 194 void crypto_morus640_glue_init_ops(struct crypto_aead *aead,
 195                                    const struct morus640_glue_ops *ops)
 196 {
 197         struct morus640_ctx *ctx = crypto_aead_ctx(aead);
 198         ctx->ops = ops;
 199 }
 200 EXPORT_SYMBOL_GPL(crypto_morus640_glue_init_ops);
 201
 202 MODULE_LICENSE("GPL");
 203 MODULE_AUTHOR("Ondrej Mosnacek <omosnacek@gmail.com>");
 204 MODULE_DESCRIPTION("MORUS-640 AEAD mode -- glue for x86 optimizations");