#include "../lib/lib.h"
#include "../lib/lib2.h"
#include "../lib/lib3.h"
#include "../lib/lib4.h"
#include "../lib/lib5.h"
#include "../lib/lib7.h"

void generate_random_printable_bytes(char *s, unsigned int length)
{
	int i;

	for(i=0;i<length;i++)
		s[i] = random_number_between(33,127);
}

// simple length extension could work with the same hash,
// to avoid that we get syntax error because of obsucre input
// makes everthings after our alter a comment, additionally ensure that
// all characters are printable aka. [33,127]
int main()
{
	int i, value;
	char *__msg = "alert('MZA who was that?');\n";
	char *msg = malloc(strlen(__msg));
	memcpy(msg, __msg, strlen(__msg));
	char *key = "YELLOW SUBMARINE";
	char iv[15];
	char mac[16];
	char hex_mac[32];

	memset(iv, 0, 16);
	cbc_mac(msg, strlen(msg), iv, key, mac);
	hex_binary_to_string(mac, hex_mac, 16);
	//printf("mac is: %s\n", hex_mac);

	char *__expand = "alert('Ayo, the Wu is back!'); //";
	char *expand = malloc(strlen(__expand)+16+16);
	memcpy(expand, __expand, strlen(__expand));
	// generate a printable version
	// ensure that padding is 0x09 (=> TAB \t)
	for(i=0;i<16;i++) {
		value = 16 - ((strlen(__expand)+i) % 16);
		// add character until value == 9 to expand
		if(value != 16)
			expand[strlen(__expand)+i] = '/';
		else
			expand[strlen(__expand)+i] = '\0';
	}
	int expand_len = strlen(expand);
	// now we have a full with 7 bytes we can change + 9 bytes padding (TAB)
	// we want to change the 7 bytes so that the result is printable
	char *concat = malloc(strlen(msg)+expand_len+9);
	int pad_len;
	while(1) {
		// construct a first block of msg so that mac[i] ^ msg[i]
		generate_random_printable_bytes(&expand[expand_len], 7);
		memset(iv, 0 ,16);
		cbc_mac(expand, expand_len+7, iv, key, mac);
		char *expand_padded = __pkcs7_padding(expand, expand_len+7, 16, &pad_len);
		if (pad_len != 9)
			printf("ERROR: padding length is nor 9: %i\n", pad_len);
		memcpy(concat, expand_padded, expand_len+7+pad_len);
		memcpy(&concat[expand_len+pad_len+7], msg, strlen(msg));

		for(i=0;i<16;i++)
			concat[i+pad_len+7+expand_len] = mac[i] ^ msg[i];

		if(isprintable(&concat[pad_len+6+expand_len], 17) == 1)
			break;
	}
	//printf("printable string is:\n");
	printf("%s", concat);
	memset(iv, 0, 16);
	cbc_mac(concat, strlen(msg)+expand_len+pad_len+7, iv, key, mac);
	hex_binary_to_string(mac, hex_mac, 16);
	//printf("mac is: %s\n", hex_mac);

}