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#include "../lib/lib.h"
#include "../lib/lib2.h"
#include "../lib/lib3.h"
#include "../lib/lib4.h"
#include <time.h>
int main(int argc, char **argv)
{
int i;
if(argc != 2)
printf("Please provide ONE key as argument!\n");
uint32_t *hex;
uint32_t *hex2;
char *text = "comment1=cooking%20MCs;userdata=foo;comment2=%20like%20a%20pound%20of%20bacon";
char *append = ";admin=true";
char *key = argv[1];
printf("Using secret key: %s\n", key);
unsigned char *padded;
// padding in MD4 is the same as in SHA1
int padding_len = sha1_padding(strlen(text), &padded);
md4_prefix_key_mac(&hex, text, strlen(text), key, strlen(key));
printf("MAC of original message:\n");
for(i=0;i<5;i++)
printf("%02x", hex[i]);
printf("\n");
/*
* We are appending a text to the original message without knowign the
* key. Actually we don't know the message here, just the length of
* the message.
*/
md4_prefix_key_forge(&hex2, append, strlen(append), hex);
printf("MAC of forged message:\n");
for(i=0;i<5;i++)
printf("%02x", hex2[i]);
printf("\n");
/*
* create the message we forged. Send this plus the hmac to the
* victim. He knows the secret and test and will think that
* this is a message from Alice
*/
unsigned int new_msg_len = strlen(text)+strlen(append)+padding_len;
char *new_msg = malloc(new_msg_len);
memcpy(new_msg, text, strlen(text));
memcpy(&new_msg[strlen(text)], padded, padding_len);
memcpy(&new_msg[strlen(text)+padding_len], append, strlen(append));
if(md4_prefix_key_verify(hex2, new_msg, new_msg_len, key, strlen(key)))
printf("Forged MAC got accepted!\n");
}
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