Approxihash is a simple tool for generation of lists of hashes based on arbitrary key-value data. The initial usecase for this tool was for testing weak hashing mechanisms in keys and identifiers used on web applications.

Assuming knowledge of a user ID, an email and a userclass, approxihash can be used as follows:

approxihash.py -k userid:d00df00f email:[email protected] user_class:admin -H sha1 md5

This command will return a list of hashes based on permutations of all of the key-value data, hashed by the supplied functions. These hashes can then be piped to other tools or pipelines, and if a hash is found to be valid, the same command can be run again with the -v flag to show what combination of elements and which hash function were used to generate the hash.

JSON input: If the -j/--json parameter is passed on the commandline, any input to STDIN will be treated as JSON. At the moment the only supported data is a dictionary of key:value pairs.

Hash functions: Approxihash supports all default hashlib functions and these can be specified on the command line using --hashfn/-H. A special ALL hash function is supported that will generate all hashes with all hash functions.

Minimum combinations: The --min-combinations/-m command line argument specifies the minimum number of parameters used for hashing - meaning that for 10 arguments with a minimum combination factor of 3, only combinations of three or more elements from the 10 items in the argument list will be hashed.

Dividers: By default the permutations of input data will not be joined by a separator. The --divider/-D flag can be used to specify a divider. Without a divider specified, hashed data for ["a","b","c"] will take combinations akin to abc. With a divider specified, the combinations will be of the form a,b,c,.

TODO.org is tracking upcoming features and/or bugs.