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 <crypto/internal/hash.h> 20 #include <linux/init.h> 21 #include <linux/module.h> 22 #include <linux/mm.h> 23 #include <linux/cryptohash.h> 24 #include <linux/types.h> 25 #include <crypto/sha.h> 26 #include <asm/byteorder.h> 27 28 static int sha1_init(struct shash_desc *desc) 29 { 30 struct sha1_state *sctx = shash_desc_ctx(desc); 31 32 *sctx = (struct sha1_state){ 33 .state = { SHA1_H0, SHA1_H1, SHA1_H2, SHA1_H3, SHA1_H4 }, 34 }; 35 36 return 0; 37 } 38 39 static int sha1_update(struct shash_desc *desc, const u8 *data, 40 unsigned int len) 41 { 42 struct sha1_state *sctx = shash_desc_ctx(desc); 43 unsigned int partial, done; 44 const u8 *src; 45 46 partial = sctx->count % SHA1_BLOCK_SIZE; 47 sctx->count += len; 48 done = 0; 49 src = data; 50 51 if ((partial + len) >= SHA1_BLOCK_SIZE) { 52 u32 temp[SHA_WORKSPACE_WORDS]; 53 54 if (partial) { 55 done = -partial; 56 memcpy(sctx->buffer + partial, data, 57 done + SHA1_BLOCK_SIZE); 58 src = sctx->buffer; 59 } 60 61 do { 62 sha_transform(sctx->state, src, temp); 63 done += SHA1_BLOCK_SIZE; 64 src = data + done; 65 } while (done + SHA1_BLOCK_SIZE <= len); 66 67 memset(temp, 0, sizeof(temp)); 68 partial = 0; 69 } 70 memcpy(sctx->buffer + partial, src, len - done); 71 72 return 0; 73 } 74 75 76 /* Add padding and return the message digest. */ 77 static int sha1_final(struct shash_desc *desc, u8 *out) 78 { 79 struct sha1_state *sctx = shash_desc_ctx(desc); 80 __be32 *dst = (__be32 *)out; 81 u32 i, index, padlen; 82 __be64 bits; 83 static const u8 padding[64] = { 0x80, }; 84 85 bits = cpu_to_be64(sctx->count << 3); 86 87 /* Pad out to 56 mod 64 */ 88 index = sctx->count & 0x3f; 89 padlen = (index < 56) ? (56 - index) : ((64+56) - index); 90 sha1_update(desc, padding, padlen); 91 92 /* Append length */ 93 sha1_update(desc, (const u8 *)&bits, sizeof(bits)); 94 95 /* Store state in digest */ 96 for (i = 0; i < 5; i++) 97 dst[i] = cpu_to_be32(sctx->state[i]); 98 99 /* Wipe context */ 100 memset(sctx, 0, sizeof *sctx); 101 102 return 0; 103 } 104 105 static int sha1_export(struct shash_desc *desc, void *out) 106 { 107 struct sha1_state *sctx = shash_desc_ctx(desc); 108 109 memcpy(out, sctx, sizeof(*sctx)); 110 return 0; 111 } 112 113 static int sha1_import(struct shash_desc *desc, const void *in) 114 { 115 struct sha1_state *sctx = shash_desc_ctx(desc); 116 117 memcpy(sctx, in, sizeof(*sctx)); 118 return 0; 119 } 120 121 static struct shash_alg alg = { 122 .digestsize = SHA1_DIGEST_SIZE, 123 .init = sha1_init, 124 .update = sha1_update, 125 .final = sha1_final, 126 .export = sha1_export, 127 .import = sha1_import, 128 .descsize = sizeof(struct sha1_state), 129 .statesize = sizeof(struct sha1_state), 130 .base = { 131 .cra_name = "sha1", 132 .cra_driver_name= "sha1-generic", 133 .cra_flags = CRYPTO_ALG_TYPE_SHASH, 134 .cra_blocksize = SHA1_BLOCK_SIZE, 135 .cra_module = THIS_MODULE, 136 } 137 }; 138 139 static int __init sha1_generic_mod_init(void) 140 { 141 return crypto_register_shash(&alg); 142 } 143 144 static void __exit sha1_generic_mod_fini(void) 145 { 146 crypto_unregister_shash(&alg); 147 } 148 149 module_init(sha1_generic_mod_init); 150 module_exit(sha1_generic_mod_fini); 151 152 MODULE_LICENSE("GPL"); 153 MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm"); 154 155 MODULE_ALIAS("sha1"); 156