Message Digests

A message digest is the output of a cryptographic hash function containing a string of bytes created by a one-way formula using the original message as input.

Message digests are designed to protect the integrity of a piece of data or media to detect changes and alterations to any part of a message.

Hashing Classes

Interface

All Hashing Functions available in this module implements the following interface:

class wolfcrypt.hashes._Hash(string=None)

A PEP 247: Cryptographic Hash Functions compliant Hash Function Interface.

classmethod new(string=None)

Creates a new hashing object and returns it. The optional string parameter, if supplied, will be immediately hashed into the object’s starting state, as if obj.update(string) was called.

copy()

Returns a separate copy of this hashing object. An update to this copy won’t affect the original object.

update(string)

Hashes string into the current state of the hashing object. update() can be called any number of times during a hashing object’s lifetime.

digest()

Returns the hash value of this hashing object as a string containing 8-bit data. The object is not altered in any way by this function; you can continue updating the object after calling this function.

hexdigest()

Returns the hash value of this hashing object as a string containing hexadecimal digits. Lowercase letters are used for the digits ‘a’ through ‘f’. Like the .digest() method, this method doesn’t alter the object.

SHA-1

Attention

NIST has deprecated SHA-1 in favor of the SHA-2 variants. New applications are strongly suggested to use SHA-2 over SHA-1.

class wolfcrypt.hashes.Sha(string=None)

SHA-1 is a cryptographic hash function standardized by NIST.

It produces an [ 160-bit | 20 bytes ] message digest.

SHA-2 family

class wolfcrypt.hashes.Sha256(string=None)

SHA-256 is a cryptographic hash function from the SHA-2 family and is standardized by NIST.

It produces a [ 256-bit | 32 bytes ] message digest.

class wolfcrypt.hashes.Sha384(string=None)

SHA-384 is a cryptographic hash function from the SHA-2 family and is standardized by NIST.

It produces a [ 384-bit | 48 bytes ] message digest.

class wolfcrypt.hashes.Sha512(string=None)

SHA-512 is a cryptographic hash function from the SHA-2 family and is standardized by NIST.

It produces a [ 512-bit | 64 bytes ] message digest.

Example

>>> from wolfcrypt.hashes import Sha256
>>>
>>> s = Sha256()
>>> s.update(b'wolf')
>>> s.update(b'crypt')
>>> s.digest()
b'\x96\xe0.{\x1c\xbc\xd6\xf1\x04\xfe\x1f\xdbFR\x02zU\x05\xb6\x86R\xb7\x00\x95\xc61\x8f\x9d\xce\r\x18D'
>>> s.hexdigest()
b'96e02e7b1cbcd6f104fe1fdb4652027a5505b68652b70095c6318f9dce0d1844'
>>>
>>> s.update(b'rocks')
>>> s.hexdigest()
b'e1a50df419d65715c48316bdc6a6f7f0485f4b26c1b107228faf17988b61c83f'
>>>
>>> Sha256(b'wolfcryptrocks').hexdigest()
b'e1a50df419d65715c48316bdc6a6f7f0485f4b26c1b107228faf17988b61c83f'
>>>
>>> Sha256.new(b'wolfcryptrocks').hexdigest()
b'e1a50df419d65715c48316bdc6a6f7f0485f4b26c1b107228faf17988b61c83f'