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 36 static 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 70 static 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 } 103 104 static 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 }; 120 121 static int __init blowfish_mod_init(void) 122 { 123 return crypto_register_alg(&alg); 124 } 125 126 static void __exit blowfish_mod_fini(void) 127 { 128 crypto_unregister_alg(&alg); 129 } 130 131 subsys_initcall(blowfish_mod_init); 132 module_exit(blowfish_mod_fini); 133 134 MODULE_LICENSE("GPL"); 135 MODULE_DESCRIPTION("Blowfish Cipher Algorithm"); 136 MODULE_ALIAS_CRYPTO("blowfish"); 137 MODULE_ALIAS_CRYPTO("blowfish-generic"); 138