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/init.h> 21 #include <linux/module.h> 22 #include <linux/string.h> 23 #include <linux/types.h> 24 #include <asm/byteorder.h> 25 26 #define MD5_DIGEST_WORDS 4 27 #define MD5_MESSAGE_BYTES 64 28 29 const u8 md5_zero_message_hash[MD5_DIGEST_SIZE] = { 30 0xd4, 0x1d, 0x8c, 0xd9, 0x8f, 0x00, 0xb2, 0x04, 31 0xe9, 0x80, 0x09, 0x98, 0xec, 0xf8, 0x42, 0x7e, 32 }; 33 EXPORT_SYMBOL_GPL(md5_zero_message_hash); 34 35 /* XXX: this stuff can be optimized */ 36 static inline void le32_to_cpu_array(u32 *buf, unsigned int words) 37 { 38 while (words--) { 39 __le32_to_cpus(buf); 40 buf++; 41 } 42 } 43 44 static inline void cpu_to_le32_array(u32 *buf, unsigned int words) 45 { 46 while (words--) { 47 __cpu_to_le32s(buf); 48 buf++; 49 } 50 } 51 52 #define F1(x, y, z) (z ^ (x & (y ^ z))) 53 #define F2(x, y, z) F1(z, x, y) 54 #define F3(x, y, z) (x ^ y ^ z) 55 #define F4(x, y, z) (y ^ (x | ~z)) 56 57 #define MD5STEP(f, w, x, y, z, in, s) \ 58 (w += f(x, y, z) + in, w = (w<<s | w>>(32-s)) + x) 59 60 static void md5_transform(__u32 *hash, __u32 const *in) 61 { 62 u32 a, b, c, d; 63 64 a = hash[0]; 65 b = hash[1]; 66 c = hash[2]; 67 d = hash[3]; 68 69 MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7); 70 MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12); 71 MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17); 72 MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22); 73 MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7); 74 MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12); 75 MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17); 76 MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22); 77 MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7); 78 MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12); 79 MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17); 80 MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22); 81 MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7); 82 MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12); 83 MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17); 84 MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22); 85 86 MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5); 87 MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9); 88 MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14); 89 MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20); 90 MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5); 91 MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9); 92 MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14); 93 MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20); 94 MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5); 95 MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9); 96 MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14); 97 MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20); 98 MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5); 99 MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9); 100 MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14); 101 MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20); 102 103 MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4); 104 MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11); 105 MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16); 106 MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23); 107 MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4); 108 MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11); 109 MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16); 110 MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23); 111 MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4); 112 MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11); 113 MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16); 114 MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23); 115 MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4); 116 MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11); 117 MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16); 118 MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23); 119 120 MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6); 121 MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10); 122 MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15); 123 MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21); 124 MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6); 125 MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10); 126 MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15); 127 MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21); 128 MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6); 129 MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10); 130 MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15); 131 MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21); 132 MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6); 133 MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10); 134 MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15); 135 MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21); 136 137 hash[0] += a; 138 hash[1] += b; 139 hash[2] += c; 140 hash[3] += d; 141 } 142 143 static inline void md5_transform_helper(struct md5_state *ctx) 144 { 145 le32_to_cpu_array(ctx->block, sizeof(ctx->block) / sizeof(u32)); 146 md5_transform(ctx->hash, ctx->block); 147 } 148 149 static int md5_init(struct shash_desc *desc) 150 { 151 struct md5_state *mctx = shash_desc_ctx(desc); 152 153 mctx->hash[0] = MD5_H0; 154 mctx->hash[1] = MD5_H1; 155 mctx->hash[2] = MD5_H2; 156 mctx->hash[3] = MD5_H3; 157 mctx->byte_count = 0; 158 159 return 0; 160 } 161 162 static int md5_update(struct shash_desc *desc, const u8 *data, unsigned int len) 163 { 164 struct md5_state *mctx = shash_desc_ctx(desc); 165 const u32 avail = sizeof(mctx->block) - (mctx->byte_count & 0x3f); 166 167 mctx->byte_count += len; 168 169 if (avail > len) { 170 memcpy((char *)mctx->block + (sizeof(mctx->block) - avail), 171 data, len); 172 return 0; 173 } 174 175 memcpy((char *)mctx->block + (sizeof(mctx->block) - avail), 176 data, avail); 177 178 md5_transform_helper(mctx); 179 data += avail; 180 len -= avail; 181 182 while (len >= sizeof(mctx->block)) { 183 memcpy(mctx->block, data, sizeof(mctx->block)); 184 md5_transform_helper(mctx); 185 data += sizeof(mctx->block); 186 len -= sizeof(mctx->block); 187 } 188 189 memcpy(mctx->block, data, len); 190 191 return 0; 192 } 193 194 static int md5_final(struct shash_desc *desc, u8 *out) 195 { 196 struct md5_state *mctx = shash_desc_ctx(desc); 197 const unsigned int offset = mctx->byte_count & 0x3f; 198 char *p = (char *)mctx->block + offset; 199 int padding = 56 - (offset + 1); 200 201 *p++ = 0x80; 202 if (padding < 0) { 203 memset(p, 0x00, padding + sizeof (u64)); 204 md5_transform_helper(mctx); 205 p = (char *)mctx->block; 206 padding = 56; 207 } 208 209 memset(p, 0, padding); 210 mctx->block[14] = mctx->byte_count << 3; 211 mctx->block[15] = mctx->byte_count >> 29; 212 le32_to_cpu_array(mctx->block, (sizeof(mctx->block) - 213 sizeof(u64)) / sizeof(u32)); 214 md5_transform(mctx->hash, mctx->block); 215 cpu_to_le32_array(mctx->hash, sizeof(mctx->hash) / sizeof(u32)); 216 memcpy(out, mctx->hash, sizeof(mctx->hash)); 217 memset(mctx, 0, sizeof(*mctx)); 218 219 return 0; 220 } 221 222 static int md5_export(struct shash_desc *desc, void *out) 223 { 224 struct md5_state *ctx = shash_desc_ctx(desc); 225 226 memcpy(out, ctx, sizeof(*ctx)); 227 return 0; 228 } 229 230 static int md5_import(struct shash_desc *desc, const void *in) 231 { 232 struct md5_state *ctx = shash_desc_ctx(desc); 233 234 memcpy(ctx, in, sizeof(*ctx)); 235 return 0; 236 } 237 238 static struct shash_alg alg = { 239 .digestsize = MD5_DIGEST_SIZE, 240 .init = md5_init, 241 .update = md5_update, 242 .final = md5_final, 243 .export = md5_export, 244 .import = md5_import, 245 .descsize = sizeof(struct md5_state), 246 .statesize = sizeof(struct md5_state), 247 .base = { 248 .cra_name = "md5", 249 .cra_flags = CRYPTO_ALG_TYPE_SHASH, 250 .cra_blocksize = MD5_HMAC_BLOCK_SIZE, 251 .cra_module = THIS_MODULE, 252 } 253 }; 254 255 static int __init md5_mod_init(void) 256 { 257 return crypto_register_shash(&alg); 258 } 259 260 static void __exit md5_mod_fini(void) 261 { 262 crypto_unregister_shash(&alg); 263 } 264 265 module_init(md5_mod_init); 266 module_exit(md5_mod_fini); 267 268 MODULE_LICENSE("GPL"); 269 MODULE_DESCRIPTION("MD5 Message Digest Algorithm"); 270 MODULE_ALIAS_CRYPTO("md5"); 271