#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)
{
	if(argc  != 2)
		printf("Please provide ONE key as argument!\n");
	unsigned int hmac[5];
	unsigned int hmac2[5];
	int i;
	unsigned char *text = "comment1=cooking%20MCs;userdata=foo;comment2=%20like%20a%20pound%20of%20bacon";
	unsigned char *append = ";admin=true";
	unsigned char *key = argv[1];
	printf("Using secret key: %s\n", key);

	unsigned char *padded;
	int padding_len = sha1_padding(strlen(key)+strlen(text), &padded);

	sha1_hmac(hmac, text, strlen(text), key, strlen(key));
	printf("MAC of original message:\n");
	for(i=0;i<5;i++)
		printf("%02x", hmac[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 hash of the orginal 
	 * message. We have to append the right padding here, e.g. the size of the
	 * *complete* message, not only append
	 */
	unsigned int new_msg_len = strlen(text)+strlen(append)+padding_len;
	unsigned 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));
	
	unsigned char *padding2;
	// mesage + padding + append + padding
	int padding2_len = sha1_padding(new_msg_len+strlen(key), &padding2);
	unsigned char *tmp2 = malloc(strlen(append)+padding2_len);
	memcpy(tmp2, append, strlen(append));
	memcpy(&tmp2[strlen(append)], padding2, padding2_len);
	sha1_hmac_forge(hmac2, tmp2, (strlen(append)+padding2_len), hmac);
	printf("MAC of forged message:\n");
	for(i=0;i<5;i++)
		printf("%02x", hmac2[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
	 */
	printf("Verifying...\n");
	if(sha1_hmac_verify(hmac2, new_msg, new_msg_len, key, strlen(key)))
			printf("Forged MAC got accepted!\n");
}