Fix: missing files from last commit

This commit is contained in:
Dorian Zedler 2022-07-04 18:04:08 +02:00
parent cab96d88c0
commit 22e15be5dc
Signed by: dorian
GPG key ID: 989DE36109AFA354
6 changed files with 145 additions and 1 deletions

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build build
md2 md2
testfile*

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#ifndef MD2_0_H
#define MD2_0_H
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
void md2_hash_0(size_t len, const uint8_t buf[], uint8_t out[16]);
void md2_checksum_0(size_t len, uint8_t* buf);
#endif // MD2_0_H

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#ifndef MD2_COMMON_H
#define MD2_COMMON_H
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
/**
* @brief Some digits of pi
*
*/
extern unsigned char MD2_PI_SUBST[256];
/**
* @brief Print a buffer for debugging
*
* @param len length
* @param buf buffer
*/
void md2_print_buf(size_t len, uint8_t buf[len]);
#endif // MD2_COMMON_H

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#include "../../lib/md2_impls/md2_0.h"
#include "../../lib/md2_impls/md2_common.h"
void md2_checksum_0(size_t len, uint8_t* buf) {
uint8_t l = 0;
for (int i = 0; i < len / 16; i++) {
for (int j = 0; j < 16; j++) {
u_int8_t c = buf[i * 16 + j];
// reference is wrong. It says: Set C[j] to S[c xor L]. But it should be:
buf[len + j] ^= MD2_PI_SUBST[c ^ l];
l = buf[len + j];
}
}
}
void md2_hash_0(size_t len, const uint8_t buf[len], uint8_t out[16]) {
// === step 1 ===
int paddingNeeded = 16 - (len % 16);
uint8_t originalPadding = paddingNeeded;
len += paddingNeeded;
// printf("len: %d\n", len);
// +16 for the checksum
uint8_t* newBuf = calloc(len + 16, sizeof(uint8_t));
// TODO: null check
memcpy(newBuf, buf, len - paddingNeeded);
// printBuf(len + 16, newBuf);
while (paddingNeeded > 0) {
newBuf[len - paddingNeeded] = originalPadding;
paddingNeeded--;
}
// printf("buf with padding: ");
// printBuf(len + 16, newBuf);
// === step 2 ===
md2_checksum_0(len, newBuf);
// printf("buf with cecksum: ");
// printBuf(len + 16, newBuf);
// === step 3 ===
uint8_t* messageDigestBuf = calloc(48, sizeof(uint8_t));
// TODO: add null check
// === step 4 ===
// <= because we need to hash the last block too
for (int i = 0; i <= (len + 16) / 16 - 1; i++) {
for (int j = 0; j < 16; j++) {
messageDigestBuf[16 + j] = newBuf[i * 16 + j];
messageDigestBuf[32 + j] =
(messageDigestBuf[16 + j] ^ messageDigestBuf[j]);
}
u_int8_t t = 0;
for (int j = 0; j < 18; j++) {
for (int k = 0; k < 48; k++) {
t = messageDigestBuf[k] = messageDigestBuf[k] ^ MD2_PI_SUBST[t];
}
t = (t + j) % 256;
}
}
// printf("messageDigestBuf: \n");
// printBuf(16, messageDigestBuf);
memcpy(out, messageDigestBuf, 16);
free(messageDigestBuf);
free(newBuf);
}

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#include "../../lib/md2_impls/md2_common.h"
// Source: https://datatracker.ietf.org/doc/html/rfc1319
unsigned char MD2_PI_SUBST[256] = {
41, 46, 67, 201, 162, 216, 124, 1, 61, 54, 84, 161, 236, 240, 6,
19, 98, 167, 5, 243, 192, 199, 115, 140, 152, 147, 43, 217, 188, 76,
130, 202, 30, 155, 87, 60, 253, 212, 224, 22, 103, 66, 111, 24, 138,
23, 229, 18, 190, 78, 196, 214, 218, 158, 222, 73, 160, 251, 245, 142,
187, 47, 238, 122, 169, 104, 121, 145, 21, 178, 7, 63, 148, 194, 16,
137, 11, 34, 95, 33, 128, 127, 93, 154, 90, 144, 50, 39, 53, 62,
204, 231, 191, 247, 151, 3, 255, 25, 48, 179, 72, 165, 181, 209, 215,
94, 146, 42, 172, 86, 170, 198, 79, 184, 56, 210, 150, 164, 125, 182,
118, 252, 107, 226, 156, 116, 4, 241, 69, 157, 112, 89, 100, 113, 135,
32, 134, 91, 207, 101, 230, 45, 168, 2, 27, 96, 37, 173, 174, 176,
185, 246, 28, 70, 97, 105, 52, 64, 126, 15, 85, 71, 163, 35, 221,
81, 175, 58, 195, 92, 249, 206, 186, 197, 234, 38, 44, 83, 13, 110,
133, 40, 132, 9, 211, 223, 205, 244, 65, 129, 77, 82, 106, 220, 55,
200, 108, 193, 171, 250, 36, 225, 123, 8, 12, 189, 177, 74, 120, 136,
149, 139, 227, 99, 232, 109, 233, 203, 213, 254, 59, 0, 29, 57, 242,
239, 183, 14, 102, 88, 208, 228, 166, 119, 114, 248, 235, 117, 75, 10,
49, 68, 80, 180, 143, 237, 31, 26, 219, 153, 141, 51, 159, 17, 131,
20};
void md2_print_buf(size_t len, uint8_t buf[len]) {
for (int i = 0; i < len; i++) {
printf("'%02x',", buf[i]);
}
printf("\n");
}

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