/* * Cryptographic API. * * Blowfish Cipher Algorithm, by Bruce Schneier. * http://www.counterpane.com/blowfish.html * * Adapted from Kerneli implementation. * * Copyright (c) Herbert Valerio Riedel <hvr@hvrlab.org> * Copyright (c) Kyle McMartin <kyle@debian.org> * Copyright (c) 2002 James Morris <jmorris@intercode.com.au> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * */ #include <linux/init.h> #include <linux/module.h> #include <linux/mm.h> #include <asm/byteorder.h> #include <linux/crypto.h> #include <linux/types.h> #include <crypto/blowfish.h> /* * Round loop unrolling macros, S is a pointer to a S-Box array * organized in 4 unsigned longs at a row. */ #define GET32_3(x) (((x) & 0xff)) #define GET32_2(x) (((x) >> (8)) & (0xff)) #define GET32_1(x) (((x) >> (16)) & (0xff)) #define GET32_0(x) (((x) >> (24)) & (0xff)) #define bf_F(x) (((S[GET32_0(x)] + S[256 + GET32_1(x)]) ^ \ S[512 + GET32_2(x)]) + S[768 + GET32_3(x)]) #define ROUND(a, b, n) ({ b ^= P[n]; a ^= bf_F(b); }) static void bf_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src) { struct bf_ctx *ctx = crypto_tfm_ctx(tfm); const __be32 *in_blk = (const __be32 *)src; __be32 *const out_blk = (__be32 *)dst; const u32 *P = ctx->p; const u32 *S = ctx->s; u32 yl = be32_to_cpu(in_blk[0]); u32 yr = be32_to_cpu(in_blk[1]); ROUND(yr, yl, 0); ROUND(yl, yr, 1); ROUND(yr, yl, 2); ROUND(yl, yr, 3); ROUND(yr, yl, 4); ROUND(yl, yr, 5); ROUND(yr, yl, 6); ROUND(yl, yr, 7); ROUND(yr, yl, 8); ROUND(yl, yr, 9); ROUND(yr, yl, 10); ROUND(yl, yr, 11); ROUND(yr, yl, 12); ROUND(yl, yr, 13); ROUND(yr, yl, 14); ROUND(yl, yr, 15); yl ^= P[16]; yr ^= P[17]; out_blk[0] = cpu_to_be32(yr); out_blk[1] = cpu_to_be32(yl); } static void bf_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src) { struct bf_ctx *ctx = crypto_tfm_ctx(tfm); const __be32 *in_blk = (const __be32 *)src; __be32 *const out_blk = (__be32 *)dst; const u32 *P = ctx->p; const u32 *S = ctx->s; u32 yl = be32_to_cpu(in_blk[0]); u32 yr = be32_to_cpu(in_blk[1]); ROUND(yr, yl, 17); ROUND(yl, yr, 16); ROUND(yr, yl, 15); ROUND(yl, yr, 14); ROUND(yr, yl, 13); ROUND(yl, yr, 12); ROUND(yr, yl, 11); ROUND(yl, yr, 10); ROUND(yr, yl, 9); ROUND(yl, yr, 8); ROUND(yr, yl, 7); ROUND(yl, yr, 6); ROUND(yr, yl, 5); ROUND(yl, yr, 4); ROUND(yr, yl, 3); ROUND(yl, yr, 2); yl ^= P[1]; yr ^= P[0]; out_blk[0] = cpu_to_be32(yr); out_blk[1] = cpu_to_be32(yl); } static struct crypto_alg alg = { .cra_name = "blowfish", .cra_driver_name = "blowfish-generic", .cra_priority = 100, .cra_flags = CRYPTO_ALG_TYPE_CIPHER, .cra_blocksize = BF_BLOCK_SIZE, .cra_ctxsize = sizeof(struct bf_ctx), .cra_alignmask = 3, .cra_module = THIS_MODULE, .cra_list = LIST_HEAD_INIT(alg.cra_list), .cra_u = { .cipher = { .cia_min_keysize = BF_MIN_KEY_SIZE, .cia_max_keysize = BF_MAX_KEY_SIZE, .cia_setkey = blowfish_setkey, .cia_encrypt = bf_encrypt, .cia_decrypt = bf_decrypt } } }; static int __init blowfish_mod_init(void) { return crypto_register_alg(&alg); } static void __exit blowfish_mod_fini(void) { crypto_unregister_alg(&alg); } module_init(blowfish_mod_init); module_exit(blowfish_mod_fini); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("Blowfish Cipher Algorithm"); MODULE_ALIAS("blowfish");