cryptography.hazmat.primitives.asymmetric.utils
decode_dss_signature(signature)
Takes in signatures generated by the DSA/ECDSA signers and returns a tuple (r, s). These signatures are ASN.1 encoded Dss-Sig-Value sequences (as defined in 3279)
- param bytes signature
The signature to decode.
- returns
The decoded tuple
(r, s).- raises ValueError
Raised if the signature is malformed.
encode_dss_signature(r, s)
Creates an ASN.1 encoded Dss-Sig-Value (as defined in 3279) from raw r and s values.
- param int r
The raw signature value
r.- param int s
The raw signature value
s.- return bytes
The encoded signature.
1.6
Prehashed can be passed as the algorithm in the RSA ~cryptography.hazmat.primitives.asymmetric.rsa.RSAPrivateKey.sign and ~cryptography.hazmat.primitives.asymmetric.rsa.RSAPublicKey.verify as well as DSA ~cryptography.hazmat.primitives.asymmetric.dsa.DSAPrivateKey.sign and ~cryptography.hazmat.primitives.asymmetric.dsa.DSAPublicKey.verify methods.
For elliptic curves it can be passed as the algorithm in ~cryptography.hazmat.primitives.asymmetric.ec.ECDSA and then used with ~cryptography.hazmat.primitives.asymmetric.ec.EllipticCurvePrivateKey.sign and ~cryptography.hazmat.primitives.asymmetric.ec.EllipticCurvePublicKey.verify .
- param algorithm
An instance of
~cryptography.hazmat.primitives.hashes.HashAlgorithm.
>>> import hashlib >>> from cryptography.hazmat.primitives import hashes >>> from cryptography.hazmat.primitives.asymmetric import ( ... padding, rsa, utils ... ) >>> private_key = rsa.generate_private_key( ... public_exponent=65537, ... key_size=2048, ... ) >>> prehashed_msg = hashlib.sha256(b"A message I want to sign").digest() >>> signature = private_key.sign( ... prehashed_msg, ... padding.PSS( ... mgf=padding.MGF1(hashes.SHA256()), ... salt_length=padding.PSS.MAX_LENGTH ... ), ... utils.Prehashed(hashes.SHA256()) ... ) >>> public_key = private_key.public_key() >>> public_key.verify( ... signature, ... prehashed_msg, ... padding.PSS( ... mgf=padding.MGF1(hashes.SHA256()), ... salt_length=padding.PSS.MAX_LENGTH ... ), ... utils.Prehashed(hashes.SHA256()) ... )