:py:mod:`pylibressl.rsa`
========================

.. py:module:: pylibressl.rsa

.. autoapi-nested-parse::

   RSA signing and encryption.

   Contains routines to sign/verify, encrypt/decrypt messages using RSA and a
   wrapper class to store RSA keypair. Also it supports generation of RSA keys
   with custom length and exponent. Note that only keys in PEM format are
   supported.

   Signing example:

   >>> from pylibressl.rsa import RSAKeypair, RSASign_SHA512
   >>>
   >>> privkey = open('private_key.pem', 'rb').read()
   >>> keypair = RSAKeypair(private_key=privkey)
   >>> signer = RSASign_SHA512(keypair)
   >>>
   >>> message = b'Example message. 1234567890'
   >>> signature = signer.sign(message)
   >>>
   >>> if signer.verify(message, signature):
   ...     print('Signature is ok')
   >>> else:
   ...     print('Signature is NOT ok!!!')

   Cipher example:

   >>> from pylibressl.rsa import RSAKeypair, RSACrypt_AES256
   >>>
   >>> privkey = open('private_key.pem', 'rb').read()
   >>> keypair = RSAKeypair(private_key=privkey)
   >>> rsacrypt = RSACrypt_AES256(keypair)
   >>>
   >>> message = b'Example message. 1234567890'
   >>> enc_message, session_key, iv = rsacrypt.encrypt(message)
   >>> decoded_message = rsacrypt.decrypt(enc_message, session_key, iv)
   >>> assert decoded_message == message



Submodules
----------
.. toctree::
   :titlesonly:
   :maxdepth: 1

   cipher/index.rst
   keygen/index.rst
   keypair/index.rst
   sign/index.rst


Package Contents
----------------

Classes
~~~~~~~

.. autoapisummary::

   pylibressl.rsa.RSAKeypair
   pylibressl.rsa.RSASign
   pylibressl.rsa.RSACrypt



Functions
~~~~~~~~~

.. autoapisummary::

   pylibressl.rsa.public_from_private
   pylibressl.rsa.generate_rsa_key



Attributes
~~~~~~~~~~

.. autoapisummary::

   pylibressl.rsa.RSASign_SHA512
   pylibressl.rsa.RSACrypt_AES256


.. py:class:: RSAKeypair(public_key=None, private_key=None)

   Bases: :py:obj:`object`

   RSA keypair container.

   .. py:method:: _set_one_key(self, key, is_public)


   .. py:method:: _set_pkey(self, public_key, private_key)


   .. py:method:: has_private_key(self)

      Returns True if private key is present in keypair.


   .. py:method:: key_size(self)

      Get key size (actually, modulus length) in bytes.



.. py:function:: public_from_private(private_key)

   Derive public key from private one.


.. py:class:: RSASign(rsa_keypair)

   Bases: :py:obj:`object`

   RSA signing class.

   .. py:method:: new(cls, digest_type, name='NewRSASign')
      :classmethod:

      Create new RSA signing class.


   .. py:method:: sign(self, message)

      Sign a message with RSA.


   .. py:method:: verify(self, message, signature)

      Verify signed message with RSA.



.. py:data:: RSASign_SHA512
   

   

.. py:class:: RSACrypt(keypair)

   Bases: :py:obj:`object`

   RSA en/decryption class.

   .. py:method:: new(cls, symmetric_cipher, name='NewRSACrypt')
      :classmethod:

      Create new RSA cipher class.


   .. py:method:: encrypt(self, data)


   .. py:method:: decrypt(self, data, session_key, iv)



.. py:data:: RSACrypt_AES256
   

   

.. py:function:: generate_rsa_key(bits=2048, exponent=65537)

   Generate RSA key.

   :param bits: key length in bits
   :param exponent: exponent value, should be odd
   :returns: private key bytestring in PEM format