Crack game

The fourth pass, Xu Yi waited a long time to find out, it is no where to be found in breach, the source code is checked again and again, is suspected of clues in the source code may not be when he finally found a strange place.

In the source code, so a:

Doubt here, and this code looks like no problem, but little to do with a specific role. Typically, the script code and are caught in between, but this one does not have any code. This is not the major, the key is, if the page using the JavaScript scripting language to language, the correct format should be:

Or, separate the script directly into another file, and then by reference. The syntax is:

In other words, the above is a reference to a document that, while the file name is just JavaScript, so out of the topic and who exactly is the use of the similarities between them, is not clear if these two concepts, really can not be found One of the doubt, of course, such a code hidden in a lot of irrelevant code, also found that if not careful can not.

Xu Yi according to the above address, that file will open, and sure enough there are things to be exact which is a ciphertext, Xu Yi knew a good choice.

To such a cipher text, do not know the encryption algorithm is also no way of. Encryption algorithm is so great that any of Xu Yi how powerful, is not simply a cipher text to crack, the crack better than software, this is just a pass code, it can not be inferred from the context, various cases are possible.

Since this is a pass through the game, then there must have what other clues, this is for sure. Thus, Xu Yi returned to the source code on the web, read them, which was found a short and encryption related code, but this code actually does not work, and have not been implemented, the only role that is disturbed. One way is to use base64 encryption encryption, Xu Yi felt once again caught the key pass.

Xu Yi reviewed the characteristics of the ciphertext bit more sure that it is encrypted using base64 ciphertext encryption algorithm was.

Base64 is more on the Internet using an algorithm, which is to solve the encryption and message transfer binary data (sound, graphics, images, etc) transmission problems that arise. In other words, the algorithm and the message closely, almost all regarded it as the default e-mail software's binary code, it has become synonymous with today's e-mail encoding.

Its main idea is to encode the input data into a string or contains only {'A'-'Z', 'a'-'z', '0 '- '9','+','/'} this 64 string of printable characters, so called "Base64" (based on 64 characters.) Its structure is simple, fast, but security in general, because this is a reversible encryption algorithm, that is just know the ciphertext, you can easily recover plaintext.

Programming in PHP, which on the built-in encryption function of such so Xu Yi will easily crack the ciphertext to get the password to enter the fifth off.

Related to the fifth page, the back simply, directly gives a 16-bit cipher text, in addition to a prompt that the password is six pure digital. 16-bit cipher text, Xu Yili moment to think of the MD5 encryption, and then contact is given, tips, Xu Yi roughly guess their inference should be good, otherwise it will not give such a hint.

See this, Xu Yi some frustration, and he estimated that this level probably would reach the peak. Because the MD5 encryption algorithm is not reversible, Xu Yi in order to crack, it can only be brute force, and write a software for six figures exhaustive, it will certainly run out of the cipher text.