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 15 #include <crypto/algapi.h> 16 #include <linux/init.h> 17 #include <linux/module.h> 18 #include <linux/mm.h> 19 #include <linux/unaligned.h> 20 #include <linux/types.h> 21 #include <crypto/blowfish.h> 22 23 /* 24 * Round loop unrolling macros, S is a pointer to a S-Box array 25 * organized in 4 unsigned longs at a row. 26 */ 27 #define GET32_3(x) (((x) & 0xff)) 28 #define GET32_2(x) (((x) >> (8)) & (0xff)) 29 #define GET32_1(x) (((x) >> (16)) & (0xff)) 30 #define GET32_0(x) (((x) >> (24)) & (0xff)) 31 32 #define bf_F(x) (((S[GET32_0(x)] + S[256 + GET32_1(x)]) ^ \ 33 S[512 + GET32_2(x)]) + S[768 + GET32_3(x)]) 34 35 #define ROUND(a, b, n) ({ b ^= P[n]; a ^= bf_F(b); }) 36 37 static void bf_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src) 38 { 39 struct bf_ctx *ctx = crypto_tfm_ctx(tfm); 40 const u32 *P = ctx->p; 41 const u32 *S = ctx->s; 42 u32 yl = get_unaligned_be32(src); 43 u32 yr = get_unaligned_be32(src + 4); 44 45 ROUND(yr, yl, 0); 46 ROUND(yl, yr, 1); 47 ROUND(yr, yl, 2); 48 ROUND(yl, yr, 3); 49 ROUND(yr, yl, 4); 50 ROUND(yl, yr, 5); 51 ROUND(yr, yl, 6); 52 ROUND(yl, yr, 7); 53 ROUND(yr, yl, 8); 54 ROUND(yl, yr, 9); 55 ROUND(yr, yl, 10); 56 ROUND(yl, yr, 11); 57 ROUND(yr, yl, 12); 58 ROUND(yl, yr, 13); 59 ROUND(yr, yl, 14); 60 ROUND(yl, yr, 15); 61 62 yl ^= P[16]; 63 yr ^= P[17]; 64 65 put_unaligned_be32(yr, dst); 66 put_unaligned_be32(yl, dst + 4); 67 } 68 69 static void bf_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src) 70 { 71 struct bf_ctx *ctx = crypto_tfm_ctx(tfm); 72 const u32 *P = ctx->p; 73 const u32 *S = ctx->s; 74 u32 yl = get_unaligned_be32(src); 75 u32 yr = get_unaligned_be32(src + 4); 76 77 ROUND(yr, yl, 17); 78 ROUND(yl, yr, 16); 79 ROUND(yr, yl, 15); 80 ROUND(yl, yr, 14); 81 ROUND(yr, yl, 13); 82 ROUND(yl, yr, 12); 83 ROUND(yr, yl, 11); 84 ROUND(yl, yr, 10); 85 ROUND(yr, yl, 9); 86 ROUND(yl, yr, 8); 87 ROUND(yr, yl, 7); 88 ROUND(yl, yr, 6); 89 ROUND(yr, yl, 5); 90 ROUND(yl, yr, 4); 91 ROUND(yr, yl, 3); 92 ROUND(yl, yr, 2); 93 94 yl ^= P[1]; 95 yr ^= P[0]; 96 97 put_unaligned_be32(yr, dst); 98 put_unaligned_be32(yl, dst + 4); 99 } 100 101 static struct crypto_alg alg = { 102 .cra_name = "blowfish", 103 .cra_driver_name = "blowfish-generic", 104 .cra_priority = 100, 105 .cra_flags = CRYPTO_ALG_TYPE_CIPHER, 106 .cra_blocksize = BF_BLOCK_SIZE, 107 .cra_ctxsize = sizeof(struct bf_ctx), 108 .cra_module = THIS_MODULE, 109 .cra_u = { .cipher = { 110 .cia_min_keysize = BF_MIN_KEY_SIZE, 111 .cia_max_keysize = BF_MAX_KEY_SIZE, 112 .cia_setkey = blowfish_setkey, 113 .cia_encrypt = bf_encrypt, 114 .cia_decrypt = bf_decrypt } } 115 }; 116 117 static int __init blowfish_mod_init(void) 118 { 119 return crypto_register_alg(&alg); 120 } 121 122 static void __exit blowfish_mod_fini(void) 123 { 124 crypto_unregister_alg(&alg); 125 } 126 127 subsys_initcall(blowfish_mod_init); 128 module_exit(blowfish_mod_fini); 129 130 MODULE_LICENSE("GPL"); 131 MODULE_DESCRIPTION("Blowfish Cipher Algorithm"); 132 MODULE_ALIAS_CRYPTO("blowfish"); 133 MODULE_ALIAS_CRYPTO("blowfish-generic"); 134