A snare - Cookie spoofing

Title Description :

Open the given link to get a very long string in the web page .

The code uses md5 Cracking failed , I don't know what the encoding method is . url Parameter transfer is generally done with base64 code .

About base64 Coding principle , You can check the details online , Here we can simply say that the three characters of the original text are replaced by four characters , The principle is ：3 individual 8 Bits converted to 4 individual 6 digit , Every 6 The number of digits only indicates ‘a’~‘z’,'A'~'Z','0'~'9','+' and '\' , common 64 individual . So if the original character is not a multiple of three , You need to add at the end 1~2 individual ‘=’ character , It will be automatically removed when decoding . therefore base64 The number of characters after encoding is a multiple of four .

We see url Parameter is ZmxhZy50eHQ, The number of characters is 11, So when decoding, you need to add a... At the end of the string '=', Solve the original as “flag.txt” .