1 /* 2 * Cryptographic API. 3 * 4 * SHA1 Secure Hash Algorithm. 5 * 6 * Derived from cryptoapi implementation, adapted for in-place 7 * scatterlist interface. 8 * 9 * Copyright (c) Alan Smithee. 10 * Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk> 11 * Copyright (c) Jean-Francois Dive <jef@linuxbe.org> 12 * 13 * This program is free software; you can redistribute it and/or modify it 14 * under the terms of the GNU General Public License as published by the Free 15 * Software Foundation; either version 2 of the License, or (at your option) 16 * any later version. 17 * 18 */ 19 #include <linux/init.h> 20 #include <linux/module.h> 21 #include <linux/mm.h> 22 #include <linux/crypto.h> 23 #include <linux/cryptohash.h> 24 #include <asm/scatterlist.h> 25 #include <asm/byteorder.h> 26 27 #define SHA1_DIGEST_SIZE 20 28 #define SHA1_HMAC_BLOCK_SIZE 64 29 30 struct sha1_ctx { 31 u64 count; 32 u32 state[5]; 33 u8 buffer[64]; 34 }; 35 36 static void sha1_init(void *ctx) 37 { 38 struct sha1_ctx *sctx = ctx; 39 static const struct sha1_ctx initstate = { 40 0, 41 { 0x67452301, 0xEFCDAB89, 0x98BADCFE, 0x10325476, 0xC3D2E1F0 }, 42 { 0, } 43 }; 44 45 *sctx = initstate; 46 } 47 48 static void sha1_update(void *ctx, const u8 *data, unsigned int len) 49 { 50 struct sha1_ctx *sctx = ctx; 51 unsigned int i, j; 52 u32 temp[SHA_WORKSPACE_WORDS]; 53 54 j = (sctx->count >> 3) & 0x3f; 55 sctx->count += len << 3; 56 57 if ((j + len) > 63) { 58 memcpy(&sctx->buffer[j], data, (i = 64-j)); 59 sha_transform(sctx->state, sctx->buffer, temp); 60 for ( ; i + 63 < len; i += 64) { 61 sha_transform(sctx->state, &data[i], temp); 62 } 63 j = 0; 64 } 65 else i = 0; 66 memset(temp, 0, sizeof(temp)); 67 memcpy(&sctx->buffer[j], &data[i], len - i); 68 } 69 70 71 /* Add padding and return the message digest. */ 72 static void sha1_final(void* ctx, u8 *out) 73 { 74 struct sha1_ctx *sctx = ctx; 75 u32 i, j, index, padlen; 76 u64 t; 77 u8 bits[8] = { 0, }; 78 static const u8 padding[64] = { 0x80, }; 79 80 t = sctx->count; 81 bits[7] = 0xff & t; t>>=8; 82 bits[6] = 0xff & t; t>>=8; 83 bits[5] = 0xff & t; t>>=8; 84 bits[4] = 0xff & t; t>>=8; 85 bits[3] = 0xff & t; t>>=8; 86 bits[2] = 0xff & t; t>>=8; 87 bits[1] = 0xff & t; t>>=8; 88 bits[0] = 0xff & t; 89 90 /* Pad out to 56 mod 64 */ 91 index = (sctx->count >> 3) & 0x3f; 92 padlen = (index < 56) ? (56 - index) : ((64+56) - index); 93 sha1_update(sctx, padding, padlen); 94 95 /* Append length */ 96 sha1_update(sctx, bits, sizeof bits); 97 98 /* Store state in digest */ 99 for (i = j = 0; i < 5; i++, j += 4) { 100 u32 t2 = sctx->state[i]; 101 out[j+3] = t2 & 0xff; t2>>=8; 102 out[j+2] = t2 & 0xff; t2>>=8; 103 out[j+1] = t2 & 0xff; t2>>=8; 104 out[j ] = t2 & 0xff; 105 } 106 107 /* Wipe context */ 108 memset(sctx, 0, sizeof *sctx); 109 } 110 111 static struct crypto_alg alg = { 112 .cra_name = "sha1", 113 .cra_flags = CRYPTO_ALG_TYPE_DIGEST, 114 .cra_blocksize = SHA1_HMAC_BLOCK_SIZE, 115 .cra_ctxsize = sizeof(struct sha1_ctx), 116 .cra_module = THIS_MODULE, 117 .cra_list = LIST_HEAD_INIT(alg.cra_list), 118 .cra_u = { .digest = { 119 .dia_digestsize = SHA1_DIGEST_SIZE, 120 .dia_init = sha1_init, 121 .dia_update = sha1_update, 122 .dia_final = sha1_final } } 123 }; 124 125 static int __init init(void) 126 { 127 return crypto_register_alg(&alg); 128 } 129 130 static void __exit fini(void) 131 { 132 crypto_unregister_alg(&alg); 133 } 134 135 module_init(init); 136 module_exit(fini); 137 138 MODULE_LICENSE("GPL"); 139 MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm"); 140