Module PKCS1_PSS

RSA digital signature protocol with appendix according to PKCS#1 PSS.

See RFC3447 or the original RSA Labs specification.

This scheme is more properly called RSASSA-PSS.

For example, a sender may authenticate a message using SHA-1 and PSS like this:

>>> from Crypto.Signature import PKCS1_PSS
>>> from Crypto.Hash import SHA
>>> from Crypto.PublicKey import RSA
>>> from Crypto import Random
>>>
>>> message = 'To be signed'
>>> key = RSA.importKey(open('privkey.der').read())
>>> h = SHA.new()
>>> h.update(message)
>>> signer = PKCS1_PSS.new(key)
>>> signature = PKCS1_PSS.sign(key)

At the receiver side, verification can be done like using the public part of the RSA key:

>>> key = RSA.importKey(open('pubkey.der').read())
>>> h = SHA.new()
>>> h.update(message)
>>> verifier = PKCS1_PSS.new(key)
>>> if verifier.verify(h, signature):
>>>     print "The signature is authentic."
>>> else:
>>>     print "The signature is not authentic."