CS:APP缓冲区溢出攻击练习题

CS:APP一书的第三章最后的练习题是一个练习缓冲区溢出攻击的题目

程序是这样的

//bufbomb.c /* Bomb program that is solved using a buffer overflow attack */ #include <stdio.h> #include <stdlib.h> #include <ctype.h> #include <malloc.h> /* Like gets, except that characters are typed as pairs of hex digits. Nondigit characters are ignored. Stops when encounters newline */ char *getxs(char *dest) { int c; int even = 1; /* Have read even number of digits */ int otherd = 0; /* Other hex digit of pair */ char *sp = dest; while ((c = getchar()) != EOF && c != '/n') { if (isxdigit(c)) { int val; if ('0' <= c && c <= '9') val = c - '0'; else if ('A' <= c && c <= 'F') val = c - 'A' + 10; else val = c - 'a' + 10; if (even) { otherd = val; even = 0; } else {