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"); 143