SHA2 secure hash¶

This module implements the interface to NIST’s secure hash algorithm, known as SHA-2. It is used in the same way as all crypto hash modules: an instance of the SHA2 class is created, then feed this object with arbitrary strings/bytes using the update() method, and at any point you can ask it for the digest of the concatenation of the strings fed to it so far.

The class supports 4 variants of SHA2, selectable in the constructor with one of the following constants:

• SHA224

• SHA256

• SHA284

• SHA512

The module is based on the C library cifra.¶

The SHA2 class¶

class SHA2(hashtype=SHA256) This class allows the generation of SHA2 hashes. It is thread safe. By default, it calculates the SHA256 variant of SHA2. This behaviour can be changed by passing a different value for hashtype

update(data) Update the sha object with the string data. Repeated calls are equivalent to a single call with the concatenation of all the arguments: m.update(a); m.update(b) is equivalent to m.update(a+b).

digest() Return the digest of the strings passed to the update method so far. This is a byte object with length depending on the SHA2 variant.

hexdigest() Like digest except the digest is returned as a string containing only hexadecimal digits.