md2.c (3142B)
1 /********************************************************************* 2 * Filename: md2.c 3 * Author: Brad Conte (brad AT bradconte.com) 4 * Copyright: 5 * Disclaimer: This code is presented "as is" without any guarantees. 6 * Details: Implementation of the MD2 hashing algorithm. 7 Algorithm specification can be found here: 8 * http://tools.ietf.org/html/rfc1319 . 9 Input is little endian byte order. 10 *********************************************************************/ 11 12 /*************************** HEADER FILES ***************************/ 13 #include <stdlib.h> 14 #include <memory.h> 15 #include "md2.h" 16 17 /**************************** VARIABLES *****************************/ 18 static const BYTE s[256] = { 19 41, 46, 67, 201, 162, 216, 124, 1, 61, 54, 84, 161, 236, 240, 6, 20 19, 98, 167, 5, 243, 192, 199, 115, 140, 152, 147, 43, 217, 188, 21 76, 130, 202, 30, 155, 87, 60, 253, 212, 224, 22, 103, 66, 111, 24, 22 138, 23, 229, 18, 190, 78, 196, 214, 218, 158, 222, 73, 160, 251, 23 245, 142, 187, 47, 238, 122, 169, 104, 121, 145, 21, 178, 7, 63, 24 148, 194, 16, 137, 11, 34, 95, 33, 128, 127, 93, 154, 90, 144, 50, 25 39, 53, 62, 204, 231, 191, 247, 151, 3, 255, 25, 48, 179, 72, 165, 26 181, 209, 215, 94, 146, 42, 172, 86, 170, 198, 79, 184, 56, 210, 27 150, 164, 125, 182, 118, 252, 107, 226, 156, 116, 4, 241, 69, 157, 28 112, 89, 100, 113, 135, 32, 134, 91, 207, 101, 230, 45, 168, 2, 27, 29 96, 37, 173, 174, 176, 185, 246, 28, 70, 97, 105, 52, 64, 126, 15, 30 85, 71, 163, 35, 221, 81, 175, 58, 195, 92, 249, 206, 186, 197, 31 234, 38, 44, 83, 13, 110, 133, 40, 132, 9, 211, 223, 205, 244, 65, 32 129, 77, 82, 106, 220, 55, 200, 108, 193, 171, 250, 36, 225, 123, 33 8, 12, 189, 177, 74, 120, 136, 149, 139, 227, 99, 232, 109, 233, 34 203, 213, 254, 59, 0, 29, 57, 242, 239, 183, 14, 102, 88, 208, 228, 35 166, 119, 114, 248, 235, 117, 75, 10, 49, 68, 80, 180, 143, 237, 36 31, 26, 219, 153, 141, 51, 159, 17, 131, 20 37 }; 38 39 /*********************** FUNCTION DEFINITIONS ***********************/ 40 void md2_transform(MD2_CTX *ctx, BYTE data[]) 41 { 42 int j,k,t; 43 44 //memcpy(&ctx->state[16], data); 45 for (j=0; j < 16; ++j) { 46 ctx->state[j + 16] = data[j]; 47 ctx->state[j + 32] = (ctx->state[j+16] ^ ctx->state[j]); 48 } 49 50 t = 0; 51 for (j = 0; j < 18; ++j) { 52 for (k = 0; k < 48; ++k) { 53 ctx->state[k] ^= s[t]; 54 t = ctx->state[k]; 55 } 56 t = (t+j) & 0xFF; 57 } 58 59 t = ctx->checksum[15]; 60 for (j=0; j < 16; ++j) { 61 ctx->checksum[j] ^= s[data[j] ^ t]; 62 t = ctx->checksum[j]; 63 } 64 } 65 66 void md2_init(MD2_CTX *ctx) 67 { 68 int i; 69 70 for (i=0; i < 48; ++i) 71 ctx->state[i] = 0; 72 for (i=0; i < 16; ++i) 73 ctx->checksum[i] = 0; 74 ctx->len = 0; 75 } 76 77 void md2_update(MD2_CTX *ctx, const BYTE data[], size_t len) 78 { 79 size_t i; 80 81 for (i = 0; i < len; ++i) { 82 ctx->data[ctx->len] = data[i]; 83 ctx->len++; 84 if (ctx->len == MD2_BLOCK_SIZE) { 85 md2_transform(ctx, ctx->data); 86 ctx->len = 0; 87 } 88 } 89 } 90 91 void md2_final(MD2_CTX *ctx, BYTE hash[]) 92 { 93 int to_pad; 94 95 to_pad = MD2_BLOCK_SIZE - ctx->len; 96 97 while (ctx->len < MD2_BLOCK_SIZE) 98 ctx->data[ctx->len++] = to_pad; 99 100 md2_transform(ctx, ctx->data); 101 md2_transform(ctx, ctx->checksum); 102 103 memcpy(hash, ctx->state, MD2_BLOCK_SIZE); 104 }