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 <linux/init.h> 19 #include <linux/module.h> 20 #include <linux/string.h> 21 #include <linux/crypto.h> 22 #include <linux/types.h> 23 #include <asm/byteorder.h> 24 25 #define MD5_DIGEST_SIZE 16 26 #define MD5_HMAC_BLOCK_SIZE 64 27 #define MD5_BLOCK_WORDS 16 28 #define MD5_HASH_WORDS 4 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 struct md5_ctx { 39 u32 hash[MD5_HASH_WORDS]; 40 u32 block[MD5_BLOCK_WORDS]; 41 u64 byte_count; 42 }; 43 44 static void md5_transform(u32 *hash, u32 const *in) 45 { 46 u32 a, b, c, d; 47 48 a = hash[0]; 49 b = hash[1]; 50 c = hash[2]; 51 d = hash[3]; 52 53 MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7); 54 MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12); 55 MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17); 56 MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22); 57 MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7); 58 MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12); 59 MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17); 60 MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22); 61 MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7); 62 MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12); 63 MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17); 64 MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22); 65 MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7); 66 MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12); 67 MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17); 68 MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22); 69 70 MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5); 71 MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9); 72 MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14); 73 MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20); 74 MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5); 75 MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9); 76 MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14); 77 MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20); 78 MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5); 79 MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9); 80 MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14); 81 MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20); 82 MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5); 83 MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9); 84 MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14); 85 MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20); 86 87 MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4); 88 MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11); 89 MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16); 90 MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23); 91 MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4); 92 MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11); 93 MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16); 94 MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23); 95 MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4); 96 MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11); 97 MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16); 98 MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23); 99 MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4); 100 MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11); 101 MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16); 102 MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23); 103 104 MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6); 105 MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10); 106 MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15); 107 MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21); 108 MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6); 109 MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10); 110 MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15); 111 MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21); 112 MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6); 113 MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10); 114 MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15); 115 MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21); 116 MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6); 117 MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10); 118 MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15); 119 MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21); 120 121 hash[0] += a; 122 hash[1] += b; 123 hash[2] += c; 124 hash[3] += d; 125 } 126 127 /* XXX: this stuff can be optimized */ 128 static inline void le32_to_cpu_array(u32 *buf, unsigned int words) 129 { 130 while (words--) { 131 __le32_to_cpus(buf); 132 buf++; 133 } 134 } 135 136 static inline void cpu_to_le32_array(u32 *buf, unsigned int words) 137 { 138 while (words--) { 139 __cpu_to_le32s(buf); 140 buf++; 141 } 142 } 143 144 static inline void md5_transform_helper(struct md5_ctx *ctx) 145 { 146 le32_to_cpu_array(ctx->block, sizeof(ctx->block) / sizeof(u32)); 147 md5_transform(ctx->hash, ctx->block); 148 } 149 150 static void md5_init(struct crypto_tfm *tfm) 151 { 152 struct md5_ctx *mctx = crypto_tfm_ctx(tfm); 153 154 mctx->hash[0] = 0x67452301; 155 mctx->hash[1] = 0xefcdab89; 156 mctx->hash[2] = 0x98badcfe; 157 mctx->hash[3] = 0x10325476; 158 mctx->byte_count = 0; 159 } 160 161 static void md5_update(struct crypto_tfm *tfm, const u8 *data, unsigned int len) 162 { 163 struct md5_ctx *mctx = crypto_tfm_ctx(tfm); 164 const u32 avail = sizeof(mctx->block) - (mctx->byte_count & 0x3f); 165 166 mctx->byte_count += len; 167 168 if (avail > len) { 169 memcpy((char *)mctx->block + (sizeof(mctx->block) - avail), 170 data, len); 171 return; 172 } 173 174 memcpy((char *)mctx->block + (sizeof(mctx->block) - avail), 175 data, avail); 176 177 md5_transform_helper(mctx); 178 data += avail; 179 len -= avail; 180 181 while (len >= sizeof(mctx->block)) { 182 memcpy(mctx->block, data, sizeof(mctx->block)); 183 md5_transform_helper(mctx); 184 data += sizeof(mctx->block); 185 len -= sizeof(mctx->block); 186 } 187 188 memcpy(mctx->block, data, len); 189 } 190 191 static void md5_final(struct crypto_tfm *tfm, u8 *out) 192 { 193 struct md5_ctx *mctx = crypto_tfm_ctx(tfm); 194 const unsigned int offset = mctx->byte_count & 0x3f; 195 char *p = (char *)mctx->block + offset; 196 int padding = 56 - (offset + 1); 197 198 *p++ = 0x80; 199 if (padding < 0) { 200 memset(p, 0x00, padding + sizeof (u64)); 201 md5_transform_helper(mctx); 202 p = (char *)mctx->block; 203 padding = 56; 204 } 205 206 memset(p, 0, padding); 207 mctx->block[14] = mctx->byte_count << 3; 208 mctx->block[15] = mctx->byte_count >> 29; 209 le32_to_cpu_array(mctx->block, (sizeof(mctx->block) - 210 sizeof(u64)) / sizeof(u32)); 211 md5_transform(mctx->hash, mctx->block); 212 cpu_to_le32_array(mctx->hash, sizeof(mctx->hash) / sizeof(u32)); 213 memcpy(out, mctx->hash, sizeof(mctx->hash)); 214 memset(mctx, 0, sizeof(*mctx)); 215 } 216 217 static struct crypto_alg alg = { 218 .cra_name = "md5", 219 .cra_flags = CRYPTO_ALG_TYPE_DIGEST, 220 .cra_blocksize = MD5_HMAC_BLOCK_SIZE, 221 .cra_ctxsize = sizeof(struct md5_ctx), 222 .cra_module = THIS_MODULE, 223 .cra_list = LIST_HEAD_INIT(alg.cra_list), 224 .cra_u = { .digest = { 225 .dia_digestsize = MD5_DIGEST_SIZE, 226 .dia_init = md5_init, 227 .dia_update = md5_update, 228 .dia_final = md5_final } } 229 }; 230 231 static int __init md5_mod_init(void) 232 { 233 return crypto_register_alg(&alg); 234 } 235 236 static void __exit md5_mod_fini(void) 237 { 238 crypto_unregister_alg(&alg); 239 } 240 241 module_init(md5_mod_init); 242 module_exit(md5_mod_fini); 243 244 MODULE_LICENSE("GPL"); 245 MODULE_DESCRIPTION("MD5 Message Digest Algorithm"); 246