| 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 <string.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 | } |