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