Fusion level02 This level has the following protections: And the code looks like: #include "../common/common.c" #define XORSZ 32 void cipher(unsigned char *blah, size_t len) { static int keyed; static unsigned int keybuf[XORSZ]; int blocks; unsigned int *blahi, j; if(keyed == 0) { int fd; fd = open("/dev/urandom", O_RDONLY); if(read(fd, &keybuf, sizeof(keybuf)) != sizeof(keybuf)) exit(EXIT_FAILURE); close(fd); keyed = 1; } blahi = (unsigned int *)(blah); blocks = (len / 4); if(len & 3) blocks += 1; for(j = 0; j < blocks; j++) { blahi[j] ^= keybuf[j % XORSZ]; } } void encrypt_file() { // http://thedailywtf.