简介

反调试的实现方法很多，不过由于android系统是开源的，所以反调试其实也不是很神秘的东西。 下面是常见的也是很多厂商都在使用，包括我们项目组也在使用的。多个方案相互结合可以实现更好反调试。

1.ptrace自己,使得android_server附加不上

void anti_ptrace() {
    ptrace(PTRACE_TRACEME, 0, 0, 0);
}

2. 检测Tracepid的值

void anti_Tracepid() {
    try
    {
    const int bufsize = 1024;
    char filename[bufsize];
    char line[bufsize];
    int pid = getpid();
    sprintf(filename, “/proc/%d/status”, pid);
    FILE* fd = fopen(filename, “r”);
    if (fd !=NULL)
    {
    while (fgets(line, bufsize, fd))
    {
    if (strncmp(line, “TracerPid”, 9) == 0)
    {
    int statue = atoi(&line[10]);
    if (statue != 0)
    {
    fclose(fd);
    int ret = kill(pid, SIGKILL);
    }
    break;
    }
    }
    fclose(fd);
    } else
    {
    // LOGD(“open %s fail…”, filename);
    }
    } catch (…)
    {

    }

}

3 检测端口号，针对android_server这个端口号

void anti_serverport() {
    const int bufsize=512;
    char filename[bufsize];
    char line[bufsize];
    int pid =getpid();
    sprintf(filename,"/proc/net/tcp");
    FILE* fd=fopen(filename,“r”);
    if(fd!=NULL){
    while(fgets(line,bufsize,fd)){
    if (strncmp(line, “5D8A”, 4)==0){
    int ret = kill(pid, SIGKILL);
    }
    }
    }
    fclose(fd);

}

4.检测这些调试进程的名字

void anti_processstatus(){
    const int bufsize = 1024;
    char filename[bufsize];
    char line[bufsize];
    char name[bufsize];
    char nameline[bufsize];
    int pid = getpid();
    //先读取Tracepid的值
    sprintf(filename, “/proc/%d/status”, pid);
    FILE *fd=fopen(filename,“r”);
    if(fd!=NULL){
    while(fgets(line,bufsize,fd)){
    if(strstr(line,“TracerPid”)!=NULL)
    {
    int statue =atoi(&line[10]);
    if(statue!=0){
    sprintf(name,"/proc/%d/cmdline",statue);
    FILE *fdname=fopen(name,“r”);
    if(fdname!= NULL){
    while(fgets(nameline,bufsize,fdname)){
    if(strstr(nameline,“android_server”)!=NULL){
    int ret=kill(pid,SIGKILL);
    }
    }
    }
    fclose(fdname);
    }
    }
    }
    }
    fclose(fd);
}

5. 检测常规放置调试文件目录：/data/local/tmp

void anti_localtmp(){
    int pid=getpid();
    const int bufsize=1024;
    char line[bufsize];
    char filename[bufsize];
    sprintf(filename,"/data/local/tmp");
    FILE *fd=fopen(filename,“r”);
    if(fd!=NULL){
    while(fgets(line,bufsize,fd)){
    if(strstr(line,“android_server”)!=NULL){
    int ret=kill(pid,SIGKILL);
    }
    }
    }
    fclose(fd);
}

6. 检测break point指令

unsigned long GetLibAddr() {
    unsigned long ret = 0;
    char name[] = “libptrace.so”;
    char buf[4096], *temp;
    int pid;
    FILE *fp;
    pid = getpid();
    sprintf(buf, “/proc/%d/maps”, pid);
    fp = fopen(buf, “r”);
    if (fp == NULL) {
    puts(“open failed”);
    goto _error;
    }
    while (fgets(buf, sizeof(buf), fp)) {
    if (strstr(buf, name)) {
    temp = strtok(buf, “-”);
    ret = strtoul(temp, NULL, 16);
    break;
    }
    }
    _error: fclose(fp);
    return ret;
}

7 通过使用Linux inotify特性来对文件的读写，以及打开等权限进行监控

void anti_debug06() {
    int ret, len, i;
    int pid6 = getpid();
    const int MAXLEN = 2048;
    char buf[1024];
    char readbuf[MAXLEN];
    int fd, wd;
    fd_set readfds;
    fd = inotify_init();
    sprintf(buf, “/proc/%d/maps”, pid6);
    wd = inotify_add_watch(fd, buf, IN_ALL_EVENTS);
    if(wd>=0){
    while (1) {
    i = 0;
    FD_ZERO(&readfds);//使得readfds清零
    FD_SET(fd, &readfds);//将fd加入readfds集合
    ret = select(fd + 1, &readfds, 0, 0, 0);
    if(ret==-1){
    break;
    }
    if (ret) {
    len = read(fd, readbuf, MAXLEN);
    while (i < len) {
    struct inotify_event *event = (struct inotify_event *) &readbuf[i];
    if ((event->mask & IN_ACCESS) || (event->mask & IN_OPEN)) {
    int ret = kill(pid6, SIGKILL);
    return;
    }
    i += sizeof(struct inotify_event) + event->len;
    }
    }

    }
    }
    inotify_rm_watch(fd, wd);
    close(fd);

}

8.检测被调试代码的前后时间的差异

int gettimeofday(struct timeval *tv,struct timezone *tz);
    void anti_debug07(){
    int pid=getpid();
    struct timeval t1;
    struct timeval t2;
    struct timezone tz;
    gettimeofday(&t1,&tz);
    gettimeofday(&t2,&tz);
    // int timeoff=gettimeofday(&t1,0)-gettimeofday(&t2,0);
    int timeoff=(t2.tv_sec)-(t1.tv_sec);
    if(timeoff>1){
    int ret=kill(pid,SIGKILL);
    return ;
    }
}