def check(self,s):
txt = c16.cbcdecrypt(s,self.iv,self.key)
for c in txt:
if ord(c) > 126 or ord(c) < 32:
raise Exception(txt)
return True
def check(self, s):
txt = c16.cbcdecrypt(s, self.iv, self.key) #这个是cbc模式的解密函数
for c in txt:
if ord(c) > 126 or ord(c) < 32:
raise Exception(txt)
return True
def myinput(self,s):
s = s.replace(";","\;").replace("=","\=")
return c16.cbcencrypt(self.prefix+s+self.suffix,self.iv,self.key)
def check(self,s):
txt = c16.cbcdecrypt(s,self.iv,self.key)
for c in txt:
if ord(c) > 126 or ord(c) < 32:
raise Exception(txt)
return True
if __name__ == "__main__":
t = c27()
enc = list(t.myinput(""))
test = "".join(enc[:16]+["\x00"]*16+enc[:16]+enc[16:])
dec = ""
try:
out = t.check(test)
print "no exception, try one more time"
sys.exit(1)
except Exception, e:
dec = str(e)
key = [chr(ord(c1)^ord(c2)) for c1,c2 in zip(dec[:16],dec[32:48])]
txt = c16.cbcdecrypt("".join(enc),"".join(key),"".join(key))
print txt.encode('string_escape')
txt = c16.cbcdecrypt(s, self.iv, self.key) #这个是cbc模式的解密函数
for c in txt:
if ord(c) > 126 or ord(c) < 32:
raise Exception(txt)
return True
#这个函数是检测每个字节是否在ascii允许的范围内（32-126）
if __name__ == "__main__":
t = c27()
enc = list(t.myinput("hahahah")) #加密信息并且用list形式保存
print 'enc is :' + "".join(enc) + '\n' #这是加密之后的信息
test = "".join(enc[:16] + ["\x00"] * 16 + enc[:16] +
enc[16:]) #这个地方把加密之后的信息故意填充把密文信息改变之后作为测试
print 'change enc is :' + test + '\n' #这个是把密文篡改之后的信息
dec = ""
try:
out = t.check(test) #这个函数是检测每个字节是否在ascii允许的范围内（32-126）
print "no exception, try one more time"
sys.exit(1)
except Exception, e:
dec = str(e)
print 'error msg:' + dec + '\n' #这里是报错信息，报错信息会泄露key
key = [chr(ord(c1) ^ ord(c2))
for c1, c2 in zip(dec[:16], dec[32:48])] #通过泄露信息还原出key
print 'recover key :' + "".join(key) + '\n'
txt = c16.cbcdecrypt("".join(enc), "".join(key), "".join(key)) #解密
print txt.encode('string_escape') #还原出消息
