The program mfterm is an interactive terminal interface for working with Mifare Classic tags. It is based on libnfc and compatible with libnfc version 1.5.1
mfterm has basic operations for displaying and changing tag data, managing Mifare keys, reading and writing 1k and 4k tags, working with tag dump files, etc..
It includes a convenient dictionary attack tool for finding Mifare keys.
It also supports a specification language that can be used to write domain specific contents specifications. The data in the tag can then be accessed using the contents definitions.
The code is available here: