In the method crypt_raw you are calculating the rounds with:
int rounds = 1 << log_rounds;

Java's int is a signed type, meaning a 1 << 31 will cause it to flip to -2147483648

Hence this loop further down will not run at all:

for (i = 0; i < rounds; i++) {
			key(password);
			key(salt);
		}


rounds needs to be of type long if 31 is supposed to be a valid parameter!