Kyle Swenson | 8d8f654 | 2021-03-15 11:02:55 -0600 | [diff] [blame] | 1 | /* |
| 2 | * Cryptographic API. |
| 3 | * |
| 4 | * Blowfish Cipher Algorithm, by Bruce Schneier. |
| 5 | * http://www.counterpane.com/blowfish.html |
| 6 | * |
| 7 | * Adapted from Kerneli implementation. |
| 8 | * |
| 9 | * Copyright (c) Herbert Valerio Riedel <hvr@hvrlab.org> |
| 10 | * Copyright (c) Kyle McMartin <kyle@debian.org> |
| 11 | * Copyright (c) 2002 James Morris <jmorris@intercode.com.au> |
| 12 | * |
| 13 | * This program is free software; you can redistribute it and/or modify |
| 14 | * it under the terms of the GNU General Public License as published by |
| 15 | * the Free Software Foundation; either version 2 of the License, or |
| 16 | * (at your option) any later version. |
| 17 | * |
| 18 | */ |
| 19 | #include <linux/init.h> |
| 20 | #include <linux/module.h> |
| 21 | #include <linux/mm.h> |
| 22 | #include <asm/byteorder.h> |
| 23 | #include <linux/crypto.h> |
| 24 | #include <linux/types.h> |
| 25 | #include <crypto/blowfish.h> |
| 26 | |
| 27 | /* |
| 28 | * Round loop unrolling macros, S is a pointer to a S-Box array |
| 29 | * organized in 4 unsigned longs at a row. |
| 30 | */ |
| 31 | #define GET32_3(x) (((x) & 0xff)) |
| 32 | #define GET32_2(x) (((x) >> (8)) & (0xff)) |
| 33 | #define GET32_1(x) (((x) >> (16)) & (0xff)) |
| 34 | #define GET32_0(x) (((x) >> (24)) & (0xff)) |
| 35 | |
| 36 | #define bf_F(x) (((S[GET32_0(x)] + S[256 + GET32_1(x)]) ^ \ |
| 37 | S[512 + GET32_2(x)]) + S[768 + GET32_3(x)]) |
| 38 | |
| 39 | #define ROUND(a, b, n) ({ b ^= P[n]; a ^= bf_F(b); }) |
| 40 | |
| 41 | static void bf_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src) |
| 42 | { |
| 43 | struct bf_ctx *ctx = crypto_tfm_ctx(tfm); |
| 44 | const __be32 *in_blk = (const __be32 *)src; |
| 45 | __be32 *const out_blk = (__be32 *)dst; |
| 46 | const u32 *P = ctx->p; |
| 47 | const u32 *S = ctx->s; |
| 48 | u32 yl = be32_to_cpu(in_blk[0]); |
| 49 | u32 yr = be32_to_cpu(in_blk[1]); |
| 50 | |
| 51 | ROUND(yr, yl, 0); |
| 52 | ROUND(yl, yr, 1); |
| 53 | ROUND(yr, yl, 2); |
| 54 | ROUND(yl, yr, 3); |
| 55 | ROUND(yr, yl, 4); |
| 56 | ROUND(yl, yr, 5); |
| 57 | ROUND(yr, yl, 6); |
| 58 | ROUND(yl, yr, 7); |
| 59 | ROUND(yr, yl, 8); |
| 60 | ROUND(yl, yr, 9); |
| 61 | ROUND(yr, yl, 10); |
| 62 | ROUND(yl, yr, 11); |
| 63 | ROUND(yr, yl, 12); |
| 64 | ROUND(yl, yr, 13); |
| 65 | ROUND(yr, yl, 14); |
| 66 | ROUND(yl, yr, 15); |
| 67 | |
| 68 | yl ^= P[16]; |
| 69 | yr ^= P[17]; |
| 70 | |
| 71 | out_blk[0] = cpu_to_be32(yr); |
| 72 | out_blk[1] = cpu_to_be32(yl); |
| 73 | } |
| 74 | |
| 75 | static void bf_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src) |
| 76 | { |
| 77 | struct bf_ctx *ctx = crypto_tfm_ctx(tfm); |
| 78 | const __be32 *in_blk = (const __be32 *)src; |
| 79 | __be32 *const out_blk = (__be32 *)dst; |
| 80 | const u32 *P = ctx->p; |
| 81 | const u32 *S = ctx->s; |
| 82 | u32 yl = be32_to_cpu(in_blk[0]); |
| 83 | u32 yr = be32_to_cpu(in_blk[1]); |
| 84 | |
| 85 | ROUND(yr, yl, 17); |
| 86 | ROUND(yl, yr, 16); |
| 87 | ROUND(yr, yl, 15); |
| 88 | ROUND(yl, yr, 14); |
| 89 | ROUND(yr, yl, 13); |
| 90 | ROUND(yl, yr, 12); |
| 91 | ROUND(yr, yl, 11); |
| 92 | ROUND(yl, yr, 10); |
| 93 | ROUND(yr, yl, 9); |
| 94 | ROUND(yl, yr, 8); |
| 95 | ROUND(yr, yl, 7); |
| 96 | ROUND(yl, yr, 6); |
| 97 | ROUND(yr, yl, 5); |
| 98 | ROUND(yl, yr, 4); |
| 99 | ROUND(yr, yl, 3); |
| 100 | ROUND(yl, yr, 2); |
| 101 | |
| 102 | yl ^= P[1]; |
| 103 | yr ^= P[0]; |
| 104 | |
| 105 | out_blk[0] = cpu_to_be32(yr); |
| 106 | out_blk[1] = cpu_to_be32(yl); |
| 107 | } |
| 108 | |
| 109 | static struct crypto_alg alg = { |
| 110 | .cra_name = "blowfish", |
| 111 | .cra_driver_name = "blowfish-generic", |
| 112 | .cra_priority = 100, |
| 113 | .cra_flags = CRYPTO_ALG_TYPE_CIPHER, |
| 114 | .cra_blocksize = BF_BLOCK_SIZE, |
| 115 | .cra_ctxsize = sizeof(struct bf_ctx), |
| 116 | .cra_alignmask = 3, |
| 117 | .cra_module = THIS_MODULE, |
| 118 | .cra_u = { .cipher = { |
| 119 | .cia_min_keysize = BF_MIN_KEY_SIZE, |
| 120 | .cia_max_keysize = BF_MAX_KEY_SIZE, |
| 121 | .cia_setkey = blowfish_setkey, |
| 122 | .cia_encrypt = bf_encrypt, |
| 123 | .cia_decrypt = bf_decrypt } } |
| 124 | }; |
| 125 | |
| 126 | static int __init blowfish_mod_init(void) |
| 127 | { |
| 128 | return crypto_register_alg(&alg); |
| 129 | } |
| 130 | |
| 131 | static void __exit blowfish_mod_fini(void) |
| 132 | { |
| 133 | crypto_unregister_alg(&alg); |
| 134 | } |
| 135 | |
| 136 | module_init(blowfish_mod_init); |
| 137 | module_exit(blowfish_mod_fini); |
| 138 | |
| 139 | MODULE_LICENSE("GPL"); |
| 140 | MODULE_DESCRIPTION("Blowfish Cipher Algorithm"); |
| 141 | MODULE_ALIAS_CRYPTO("blowfish"); |
| 142 | MODULE_ALIAS_CRYPTO("blowfish-generic"); |