1 /* 2 * Cryptographic API. 3 * 4 * MD5 Message Digest Algorithm (RFC1321). 5 * 6 * Derived from cryptoapi implementation, originally based on the 7 * public domain implementation written by Colin Plumb in 1993. 8 * 9 * Copyright (c) Cryptoapi developers. 10 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au> 11 * 12 * This program is free software; you can redistribute it and/or modify it 13 * under the terms of the GNU General Public License as published by the Free 14 * Software Foundation; either version 2 of the License, or (at your option) 15 * any later version. 16 * 17 */ 18 #include <crypto/internal/hash.h> 19 #include <crypto/md5.h> 20 #include <linux/kernel.h> 21 #include <linux/module.h> 22 #include <linux/string.h> 23 24 const u8 md5_zero_message_hash[MD5_DIGEST_SIZE] = { 25 0xd4, 0x1d, 0x8c, 0xd9, 0x8f, 0x00, 0xb2, 0x04, 26 0xe9, 0x80, 0x09, 0x98, 0xec, 0xf8, 0x42, 0x7e, 27 }; 28 EXPORT_SYMBOL_GPL(md5_zero_message_hash); 29 30 #define F1(x, y, z) (z ^ (x & (y ^ z))) 31 #define F2(x, y, z) F1(z, x, y) 32 #define F3(x, y, z) (x ^ y ^ z) 33 #define F4(x, y, z) (y ^ (x | ~z)) 34 35 #define MD5STEP(f, w, x, y, z, in, s) \ 36 (w += f(x, y, z) + in, w = (w<<s | w>>(32-s)) + x) 37 38 static void md5_transform(__u32 *hash, __u32 const *in) 39 { 40 u32 a, b, c, d; 41 42 a = hash[0]; 43 b = hash[1]; 44 c = hash[2]; 45 d = hash[3]; 46 47 MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7); 48 MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12); 49 MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17); 50 MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22); 51 MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7); 52 MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12); 53 MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17); 54 MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22); 55 MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7); 56 MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12); 57 MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17); 58 MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22); 59 MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7); 60 MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12); 61 MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17); 62 MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22); 63 64 MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5); 65 MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9); 66 MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14); 67 MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20); 68 MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5); 69 MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9); 70 MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14); 71 MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20); 72 MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5); 73 MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9); 74 MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14); 75 MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20); 76 MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5); 77 MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9); 78 MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14); 79 MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20); 80 81 MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4); 82 MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11); 83 MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16); 84 MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23); 85 MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4); 86 MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11); 87 MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16); 88 MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23); 89 MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4); 90 MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11); 91 MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16); 92 MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23); 93 MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4); 94 MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11); 95 MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16); 96 MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23); 97 98 MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6); 99 MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10); 100 MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15); 101 MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21); 102 MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6); 103 MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10); 104 MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15); 105 MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21); 106 MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6); 107 MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10); 108 MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15); 109 MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21); 110 MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6); 111 MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10); 112 MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15); 113 MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21); 114 115 hash[0] += a; 116 hash[1] += b; 117 hash[2] += c; 118 hash[3] += d; 119 } 120 121 static inline void md5_transform_helper(struct md5_state *ctx, 122 u32 block[MD5_BLOCK_WORDS]) 123 { 124 le32_to_cpu_array(block, MD5_BLOCK_WORDS); 125 md5_transform(ctx->hash, block); 126 } 127 128 static int md5_init(struct shash_desc *desc) 129 { 130 struct md5_state *mctx = shash_desc_ctx(desc); 131 132 mctx->hash[0] = MD5_H0; 133 mctx->hash[1] = MD5_H1; 134 mctx->hash[2] = MD5_H2; 135 mctx->hash[3] = MD5_H3; 136 mctx->byte_count = 0; 137 138 return 0; 139 } 140 141 static int md5_update(struct shash_desc *desc, const u8 *data, unsigned int len) 142 { 143 struct md5_state *mctx = shash_desc_ctx(desc); 144 u32 block[MD5_BLOCK_WORDS]; 145 146 mctx->byte_count += len; 147 do { 148 memcpy(block, data, sizeof(block)); 149 md5_transform_helper(mctx, block); 150 data += sizeof(block); 151 len -= sizeof(block); 152 } while (len >= sizeof(block)); 153 memzero_explicit(block, sizeof(block)); 154 mctx->byte_count -= len; 155 return len; 156 } 157 158 static int md5_finup(struct shash_desc *desc, const u8 *data, unsigned int len, 159 u8 *out) 160 { 161 struct md5_state *mctx = shash_desc_ctx(desc); 162 u32 block[MD5_BLOCK_WORDS]; 163 unsigned int offset; 164 int padding; 165 char *p; 166 167 memcpy(block, data, len); 168 169 offset = len; 170 p = (char *)block + offset; 171 padding = 56 - (offset + 1); 172 173 *p++ = 0x80; 174 if (padding < 0) { 175 memset(p, 0x00, padding + sizeof (u64)); 176 md5_transform_helper(mctx, block); 177 p = (char *)block; 178 padding = 56; 179 } 180 181 memset(p, 0, padding); 182 mctx->byte_count += len; 183 block[14] = mctx->byte_count << 3; 184 block[15] = mctx->byte_count >> 29; 185 le32_to_cpu_array(block, (sizeof(block) - sizeof(u64)) / sizeof(u32)); 186 md5_transform(mctx->hash, block); 187 memzero_explicit(block, sizeof(block)); 188 cpu_to_le32_array(mctx->hash, sizeof(mctx->hash) / sizeof(u32)); 189 memcpy(out, mctx->hash, sizeof(mctx->hash)); 190 191 return 0; 192 } 193 194 static struct shash_alg alg = { 195 .digestsize = MD5_DIGEST_SIZE, 196 .init = md5_init, 197 .update = md5_update, 198 .finup = md5_finup, 199 .descsize = MD5_STATE_SIZE, 200 .base = { 201 .cra_name = "md5", 202 .cra_driver_name = "md5-generic", 203 .cra_flags = CRYPTO_AHASH_ALG_BLOCK_ONLY, 204 .cra_blocksize = MD5_HMAC_BLOCK_SIZE, 205 .cra_module = THIS_MODULE, 206 } 207 }; 208 209 static int __init md5_mod_init(void) 210 { 211 return crypto_register_shash(&alg); 212 } 213 214 static void __exit md5_mod_fini(void) 215 { 216 crypto_unregister_shash(&alg); 217 } 218 219 module_init(md5_mod_init); 220 module_exit(md5_mod_fini); 221 222 MODULE_LICENSE("GPL"); 223 MODULE_DESCRIPTION("MD5 Message Digest Algorithm"); 224 MODULE_ALIAS_CRYPTO("md5"); 225