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codeql/python/ql/test/library-tests/frameworks/crypto/test_dsa.py
Rasmus Wriedt Larsen d9079e34e3 Python: Move framework tests out of experimental
Since they are not experimental anymore 😄
2021-03-19 15:51:54 +01:00

42 lines
1.1 KiB
Python

# DSA is a public-key algorithm for signing messages.
# Following example at https://pycryptodome.readthedocs.io/en/latest/src/signature/dsa.html
from Crypto.PublicKey import DSA
from Crypto.Signature import DSS
from Crypto.Hash import SHA256
private_key = DSA.generate(2048) # $ PublicKeyGeneration keySize=2048
public_key = private_key.publickey()
# ------------------------------------------------------------------------------
# sign/verify
# ------------------------------------------------------------------------------
print("sign/verify")
message = b"message"
signer = DSS.new(private_key, mode='fips-186-3')
hasher = SHA256.new(message)
signature = signer.sign(hasher)
print("signature={}".format(signature))
print()
verifier = DSS.new(public_key, mode='fips-186-3')
hasher = SHA256.new(message)
verifier.verify(hasher, signature)
print("Signature verified (as expected)")
try:
hasher = SHA256.new(b"other message")
verifier.verify(hasher, signature)
raise Exception("Signature verified (unexpected)")
except ValueError:
print("Signature mismatch (as expected)")