This is a preview version of the DisplayLink DL-7450 Software Development Kit Documentation. The functionality that is described and made available in this version is subject to addition, removal or change without warning.

class HMAC – Keyed Hashing for Message Authentication

Objects of the HMAC class have the following methods

class hmac.HMAC(key, msg=None, digestmod=None)

Create an HMAC object. Equivalent to and called by hmac.new.

copy(): Returns a copy of this HMAC object. The original and the copy can be updated independently.

Note

Not implemented for hashlib built-in hash functions

update(msg)

Feed more data from the message into this object:

import hashlib
import hmac
from splashscreen import Splashscreen

screen = Splashscreen()
m = hmac.new(b"key", b"hello", hashlib.md5)
m.update(b", world")
screen.add_text_box(f"digest: {m.digest()}")

# Displays:
# digest: b'4LF\xd2O|\xcc\x1c\x99\x1clp@x\xe8\\'

digest(): Return the hash value of this hashing object. Returns the hmac value as bytes. If the underlying hash function’s digest method is final, then this method is also final.

hexdigest()

Like digest, but returns a string of hexadecimal digits instead.

import hashlib
import hmac
from splashscreen import Splashscreen

screen = Splashscreen()
m = hmac.new(b"key", b"hello, world", hashlib.md5)
screen.add_text_box(f"hexdigest: {m.hexdigest()}")

# Displays:
# hexdigest: 344c46d24f7ccc1c991c6c704078e85c

property block_size: The internal block size of the underlying hash algorithm in bytes.

property digest_size: The size of the resulting digest in bytes; only supported if the underlying hash function has the digest_size attribute.