arch/mips/crypto/chacha-glue.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * MIPS accelerated ChaCha and XChaCha stream ciphers,
   4  * including ChaCha20 (RFC7539)
   5  *
   6  * Copyright (C) 2019 Linaro, Ltd. <ard.biesheuvel@linaro.org>
   7  */
   8
   9 #include <asm/byteorder.h>
  10 #include <crypto/algapi.h>
  11 #include <crypto/internal/chacha.h>
  12 #include <crypto/internal/skcipher.h>
  13 #include <linux/kernel.h>
  14 #include <linux/module.h>
  15
  16 asmlinkage void chacha_crypt_arch(u32 *state, u8 *dst, const u8 *src,
  17                                   unsigned int bytes, int nrounds);
  18 EXPORT_SYMBOL(chacha_crypt_arch);
  19
  20 asmlinkage void hchacha_block_arch(const u32 *state, u32 *stream, int nrounds);
  21 EXPORT_SYMBOL(hchacha_block_arch);
  22
  23 void chacha_init_arch(u32 *state, const u32 *key, const u8 *iv)
  24 {
  25         chacha_init_generic(state, key, iv);
  26 }
  27 EXPORT_SYMBOL(chacha_init_arch);
  28
  29 static int chacha_mips_stream_xor(struct skcipher_request *req,
  30                                   const struct chacha_ctx *ctx, const u8 *iv)
  31 {
  32         struct skcipher_walk walk;
  33         u32 state[16];
  34         int err;
  35
  36         err = skcipher_walk_virt(&walk, req, false);
  37
  38         chacha_init_generic(state, ctx->key, iv);
  39
  40         while (walk.nbytes > 0) {
  41                 unsigned int nbytes = walk.nbytes;
  42
  43                 if (nbytes < walk.total)
  44                         nbytes = round_down(nbytes, walk.stride);
  45
  46                 chacha_crypt(state, walk.dst.virt.addr, walk.src.virt.addr,
  47                              nbytes, ctx->nrounds);
  48                 err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
  49         }
  50
  51         return err;
  52 }
  53
  54 static int chacha_mips(struct skcipher_request *req)
  55 {
  56         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
  57         struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
  58
  59         return chacha_mips_stream_xor(req, ctx, req->iv);
  60 }
  61
  62 static int xchacha_mips(struct skcipher_request *req)
  63 {
  64         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
  65         struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
  66         struct chacha_ctx subctx;
  67         u32 state[16];
  68         u8 real_iv[16];
  69
  70         chacha_init_generic(state, ctx->key, req->iv);
  71
  72         hchacha_block(state, subctx.key, ctx->nrounds);
  73         subctx.nrounds = ctx->nrounds;
  74
  75         memcpy(&real_iv[0], req->iv + 24, 8);
  76         memcpy(&real_iv[8], req->iv + 16, 8);
  77         return chacha_mips_stream_xor(req, &subctx, real_iv);
  78 }
  79
  80 static struct skcipher_alg algs[] = {
  81         {
  82                 .base.cra_name          = "chacha20",
  83                 .base.cra_driver_name   = "chacha20-mips",
  84                 .base.cra_priority      = 200,
  85                 .base.cra_blocksize     = 1,
  86                 .base.cra_ctxsize       = sizeof(struct chacha_ctx),
  87                 .base.cra_module        = THIS_MODULE,
  88
  89                 .min_keysize            = CHACHA_KEY_SIZE,
  90                 .max_keysize            = CHACHA_KEY_SIZE,
  91                 .ivsize                 = CHACHA_IV_SIZE,
  92                 .chunksize              = CHACHA_BLOCK_SIZE,
  93                 .setkey                 = chacha20_setkey,
  94                 .encrypt                = chacha_mips,
  95                 .decrypt                = chacha_mips,
  96         }, {
  97                 .base.cra_name          = "xchacha20",
  98                 .base.cra_driver_name   = "xchacha20-mips",
  99                 .base.cra_priority      = 200,
 100                 .base.cra_blocksize     = 1,
 101                 .base.cra_ctxsize       = sizeof(struct chacha_ctx),
 102                 .base.cra_module        = THIS_MODULE,
 103
 104                 .min_keysize            = CHACHA_KEY_SIZE,
 105                 .max_keysize            = CHACHA_KEY_SIZE,
 106                 .ivsize                 = XCHACHA_IV_SIZE,
 107                 .chunksize              = CHACHA_BLOCK_SIZE,
 108                 .setkey                 = chacha20_setkey,
 109                 .encrypt                = xchacha_mips,
 110                 .decrypt                = xchacha_mips,
 111         }, {
 112                 .base.cra_name          = "xchacha12",
 113                 .base.cra_driver_name   = "xchacha12-mips",
 114                 .base.cra_priority      = 200,
 115                 .base.cra_blocksize     = 1,
 116                 .base.cra_ctxsize       = sizeof(struct chacha_ctx),
 117                 .base.cra_module        = THIS_MODULE,
 118
 119                 .min_keysize            = CHACHA_KEY_SIZE,
 120                 .max_keysize            = CHACHA_KEY_SIZE,
 121                 .ivsize                 = XCHACHA_IV_SIZE,
 122                 .chunksize              = CHACHA_BLOCK_SIZE,
 123                 .setkey                 = chacha12_setkey,
 124                 .encrypt                = xchacha_mips,
 125                 .decrypt                = xchacha_mips,
 126         }
 127 };
 128
 129 static int __init chacha_simd_mod_init(void)
 130 {
 131         return IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER) ?
 132                 crypto_register_skciphers(algs, ARRAY_SIZE(algs)) : 0;
 133 }
 134
 135 static void __exit chacha_simd_mod_fini(void)
 136 {
 137         if (IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER))
 138                 crypto_unregister_skciphers(algs, ARRAY_SIZE(algs));
 139 }
 140
 141 module_init(chacha_simd_mod_init);
 142 module_exit(chacha_simd_mod_fini);
 143
 144 MODULE_DESCRIPTION("ChaCha and XChaCha stream ciphers (MIPS accelerated)");
 145 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
 146 MODULE_LICENSE("GPL v2");
 147 MODULE_ALIAS_CRYPTO("chacha20");
 148 MODULE_ALIAS_CRYPTO("chacha20-mips");
 149 MODULE_ALIAS_CRYPTO("xchacha20");
 150 MODULE_ALIAS_CRYPTO("xchacha20-mips");
 151 MODULE_ALIAS_CRYPTO("xchacha12");
 152 MODULE_ALIAS_CRYPTO("xchacha12-mips");