clbg/treehash

Python implementation of tree hashing used by Amazon Glacier

Tree Hash Calculator

Calculates a SHA256 (or, potentially, any other hashlib supported function) "tree" hash, as used by e.g. Amazon Glacier.

Command line usage:

$ treehash <filename> ...

As a library, we follow the hashlib conventions. That is:

>>> from treehash import TreeHash
>>> treehash = TreeHash()
>>> treehash.update(b"Nobody inspects")
>>> treehash.update(b" the spammish repetition")
>>> treehash.digest()
'\x03\x1e\xdd}Ae\x15\x93\xc5\xfe\\\x00o\xa5u+7\xfd\xdf\xf7\xbcN\x84:\xa6\xaf\x0c\x95\x0fK\x94\x06'
>>> treehash.hexdigest()
'031edd7d41651593c5fe5c006fa5752b37fddff7bc4e843aa6af0c950f4b9406'

Note that it is possible to specify the block size (Glacier uses 1 MB) and hash algorithm used:

>>> treehash = TreeHash(algo=hashlib.md5, block_size=2048*2048)