MifareClassicTool | Android NFC app for reading

First of all, you need the keys for the tag you want to read. Due to some weaknesses in MIFARE Classic, you can retrieve all the keys (A and B) of a tag with tools like the [Proxmark3](http://www.proxmark.org/) or normal RFID-Readers and some special software ([mfcuk](https://github.com/nfc-tools/mfcuk), [mfoc](https://github.com/nfc-tools/mfoc)). The application comes with standard key files called std.keys and extended-std.keys, which contain the well known keys and some standard keys from a short Google search. You can try to read a tag with these key files using "Read Tag" from the main menu. Changes to these key files will be lost. Create your own key file for your keys. Once you know some keys, you can put them into a simple text file (one key per line). You can do this on your PC and import the file using MCT’s import/export tool, or you can create a new key file via "Edit or Add Key File" from the main menu. If you are finished setting up your key file, you can read a tag using "Read Tag" from the main menu. Advantages of the Key Files Concept: * You don’t have to worry about which key is for which sector. The application tries to authenticate with all keys from the key file (dictionary). * You don’t have to know all the keys. If neither key A nor key B for a specific sector is found in the key file (dictionary), the application will skip reading said sector.