void memxor(uint8_t * dest, uint8_t * src, size_t len);
char *strncat(char *dest, const char *src, unsigned int n);
char *strcat(char *dest, const char *src);
void strreverse(char s[]);
void itoa(int n, char s[]);
void memxor(uint8_t * dest, uint8_t * src, size_t len);
char *strncat(char *dest, const char *src, unsigned int n);
char *strcat(char *dest, const char *src);
void strreverse(char s[]);
void itoa(int n, char s[]);