LXR linux/crypto/blowfish

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Cryptographic API.
   4 *
   5 * Blowfish Cipher Algorithm, by Bruce Schneier.
   6 * http://www.counterpane.com/blowfish.html
   7 *
   8 * Adapted from Kerneli implementation.
   9 *
  10 * Copyright (c) Herbert Valerio Riedel <hvr@hvrlab.org>
  11 * Copyright (c) Kyle McMartin <kyle@debian.org>
  12 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
  13 */
  14#include <linux/init.h>
  15#include <linux/module.h>
  16#include <linux/mm.h>
  17#include <asm/byteorder.h>
  18#include <linux/crypto.h>
  19#include <linux/types.h>
  20#include <crypto/blowfish.h>
  21
  22/*
  23 * Round loop unrolling macros, S is a pointer to a S-Box array
  24 * organized in 4 unsigned longs at a row.
  25 */
  26#define GET32_3(x) (((x) & 0xff))
  27#define GET32_2(x) (((x) >> (8)) & (0xff))
  28#define GET32_1(x) (((x) >> (16)) & (0xff))
  29#define GET32_0(x) (((x) >> (24)) & (0xff))
  30
  31#define bf_F(x) (((S[GET32_0(x)] + S[256 + GET32_1(x)]) ^ \
  32                S[512 + GET32_2(x)]) + S[768 + GET32_3(x)])
  33
  34#define ROUND(a, b, n) ({ b ^= P[n]; a ^= bf_F(b); })
  35
  36static void bf_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
  37{
  38        struct bf_ctx *ctx = crypto_tfm_ctx(tfm);
  39        const __be32 *in_blk = (const __be32 *)src;
  40        __be32 *const out_blk = (__be32 *)dst;
  41        const u32 *P = ctx->p;
  42        const u32 *S = ctx->s;
  43        u32 yl = be32_to_cpu(in_blk[0]);
  44        u32 yr = be32_to_cpu(in_blk[1]);
  45
  46        ROUND(yr, yl, 0);
  47        ROUND(yl, yr, 1);
  48        ROUND(yr, yl, 2);
  49        ROUND(yl, yr, 3);
  50        ROUND(yr, yl, 4);
  51        ROUND(yl, yr, 5);
  52        ROUND(yr, yl, 6);
  53        ROUND(yl, yr, 7);
  54        ROUND(yr, yl, 8);
  55        ROUND(yl, yr, 9);
  56        ROUND(yr, yl, 10);
  57        ROUND(yl, yr, 11);
  58        ROUND(yr, yl, 12);
  59        ROUND(yl, yr, 13);
  60        ROUND(yr, yl, 14);
  61        ROUND(yl, yr, 15);
  62
  63        yl ^= P[16];
  64        yr ^= P[17];
  65
  66        out_blk[0] = cpu_to_be32(yr);
  67        out_blk[1] = cpu_to_be32(yl);
  68}
  69
  70static void bf_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
  71{
  72        struct bf_ctx *ctx = crypto_tfm_ctx(tfm);
  73        const __be32 *in_blk = (const __be32 *)src;
  74        __be32 *const out_blk = (__be32 *)dst;
  75        const u32 *P = ctx->p;
  76        const u32 *S = ctx->s;
  77        u32 yl = be32_to_cpu(in_blk[0]);
  78        u32 yr = be32_to_cpu(in_blk[1]);
  79
  80        ROUND(yr, yl, 17);
  81        ROUND(yl, yr, 16);
  82        ROUND(yr, yl, 15);
  83        ROUND(yl, yr, 14);
  84        ROUND(yr, yl, 13);
  85        ROUND(yl, yr, 12);
  86        ROUND(yr, yl, 11);
  87        ROUND(yl, yr, 10);
  88        ROUND(yr, yl, 9);
  89        ROUND(yl, yr, 8);
  90        ROUND(yr, yl, 7);
  91        ROUND(yl, yr, 6);
  92        ROUND(yr, yl, 5);
  93        ROUND(yl, yr, 4);
  94        ROUND(yr, yl, 3);
  95        ROUND(yl, yr, 2);
  96
  97        yl ^= P[1];
  98        yr ^= P[0];
  99
 100        out_blk[0] = cpu_to_be32(yr);
 101        out_blk[1] = cpu_to_be32(yl);
 102}
 103
 104static struct crypto_alg alg = {
 105        .cra_name               =       "blowfish",
 106        .cra_driver_name        =       "blowfish-generic",
 107        .cra_priority           =       100,
 108        .cra_flags              =       CRYPTO_ALG_TYPE_CIPHER,
 109        .cra_blocksize          =       BF_BLOCK_SIZE,
 110        .cra_ctxsize            =       sizeof(struct bf_ctx),
 111        .cra_alignmask          =       3,
 112        .cra_module             =       THIS_MODULE,
 113        .cra_u                  =       { .cipher = {
 114        .cia_min_keysize        =       BF_MIN_KEY_SIZE,
 115        .cia_max_keysize        =       BF_MAX_KEY_SIZE,
 116        .cia_setkey             =       blowfish_setkey,
 117        .cia_encrypt            =       bf_encrypt,
 118        .cia_decrypt            =       bf_decrypt } }
 119};
 120
 121static int __init blowfish_mod_init(void)
 122{
 123        return crypto_register_alg(&alg);
 124}
 125
 126static void __exit blowfish_mod_fini(void)
 127{
 128        crypto_unregister_alg(&alg);
 129}
 130
 131subsys_initcall(blowfish_mod_init);
 132module_exit(blowfish_mod_fini);
 133
 134MODULE_LICENSE("GPL");
 135MODULE_DESCRIPTION("Blowfish Cipher Algorithm");
 136MODULE_ALIAS_CRYPTO("blowfish");
 137MODULE_ALIAS_CRYPTO("blowfish-generic");
 138