# Author: Trevor Perrin
# See the LICENSE file for legal information regarding use of this file.
"""Factory functions for asymmetric cryptography."""
from .compat import *
from .rsakey import RSAKey
from .python_rsakey import Python_RSAKey
from .python_ecdsakey import Python_ECDSAKey
from .python_dsakey import Python_DSAKey
from .python_eddsakey import Python_EdDSAKey
from tlslite.utils import cryptomath
if cryptomath.m2cryptoLoaded:
from .openssl_rsakey import OpenSSL_RSAKey
if cryptomath.pycryptoLoaded:
from .pycrypto_rsakey import PyCrypto_RSAKey
# **************************************************************************
# Factory Functions for RSA Keys
# **************************************************************************
[docs]
def generateRSAKey(bits, implementations=["openssl", "python"]):
"""Generate an RSA key with the specified bit length.
:type bits: int
:param bits: Desired bit length of the new key's modulus.
:rtype: ~tlslite.utils.rsakey.RSAKey
:returns: A new RSA private key.
"""
for implementation in implementations:
if implementation == "openssl" and cryptomath.m2cryptoLoaded:
return OpenSSL_RSAKey.generate(bits)
elif implementation == "python":
return Python_RSAKey.generate(bits)
raise ValueError("No acceptable implementations")
#Parse as an OpenSSL or Python key
[docs]
def parsePEMKey(s, private=False, public=False, passwordCallback=None,
implementations=["openssl", "python"]):
"""Parse a PEM-format key.
The PEM format is used by OpenSSL and other tools. The
format is typically used to store both the public and private
components of a key. For example::
-----BEGIN RSA PRIVATE KEY-----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-----END RSA PRIVATE KEY-----
To generate a key like this with OpenSSL, run::
openssl genrsa 2048 > key.pem
This format also supports password-encrypted private keys. TLS
Lite can only handle password-encrypted private keys when OpenSSL
and M2Crypto are installed. In this case, passwordCallback will be
invoked to query the user for the password.
:type s: str
:param s: A string containing a PEM-encoded public or private key.
:type private: bool
:param private: If True, a :py:class:`SyntaxError` will be raised if the
private key component is not present.
:type public: bool
:param public: If True, the private key component (if present) will
be discarded, so this function will always return a public key.
:type passwordCallback: callable
:param passwordCallback: This function will be called, with no
arguments, if the PEM-encoded private key is password-encrypted.
The callback should return the password string. If the password is
incorrect, SyntaxError will be raised. If no callback is passed
and the key is password-encrypted, a prompt will be displayed at
the console.
:rtype: ~tlslite.utils.rsakey.RSAKey
:returns: An RSA key.
:raises SyntaxError: If the key is not properly formatted.
"""
# as old versions of openssl can't handle RSA-PSS or ECDSA keys, first
# try to detect what kind of key it is (we ignore errors as the python
# code can't handle encrypted key files while m2crypto/openssl can)
key_type = "rsa"
try:
key = Python_RSAKey.parsePEM(s)
key_type = key.key_type
del key
except Exception:
pass
for implementation in implementations:
if implementation == "openssl" and cryptomath.m2cryptoLoaded \
and key_type == "rsa":
key = OpenSSL_RSAKey.parse(s, passwordCallback)
break
elif implementation == "python":
key = Python_RSAKey.parsePEM(s)
break
else:
raise ValueError("No acceptable implementations")
return _parseKeyHelper(key, private, public)
def _parseKeyHelper(key, private, public):
if private and not key.hasPrivateKey():
raise SyntaxError("Not a private key!")
if public:
return _createPublicKey(key)
if private:
if cryptomath.m2cryptoLoaded:
if type(key) == Python_RSAKey:
return _createPrivateKey(key)
assert type(key) in (OpenSSL_RSAKey, Python_ECDSAKey,
Python_DSAKey, Python_EdDSAKey), type(key)
return key
elif hasattr(key, "d"):
return _createPrivateKey(key)
return key
[docs]
def parseAsPublicKey(s):
"""Parse a PEM-formatted public key.
:type s: str
:param s: A string containing a PEM-encoded public or private key.
:rtype: ~tlslite.utils.rsakey.RSAKey
:returns: An RSA public key.
:raises SyntaxError: If the key is not properly formatted.
"""
return parsePEMKey(s, public=True)
[docs]
def parsePrivateKey(s):
"""Parse a PEM-formatted private key.
:type s: str
:param s: A string containing a PEM-encoded private key.
:rtype: ~tlslite.utils.rsakey.RSAKey
:returns: An RSA private key.
:raises SyntaxError: If the key is not properly formatted.
"""
return parsePEMKey(s, private=True)
def _createPublicKey(key):
"""
Create a new public key. Discard any private component,
and return the most efficient key possible.
"""
if not isinstance(key, RSAKey):
raise AssertionError()
return _createPublicRSAKey(key.n, key.e, key.key_type)
def _createPrivateKey(key):
"""
Create a new private key. Return the most efficient key possible.
"""
if not isinstance(key, RSAKey):
raise AssertionError()
if not key.hasPrivateKey():
raise AssertionError()
return _createPrivateRSAKey(key.n, key.e, key.d, key.p, key.q, key.dP,
key.dQ, key.qInv, key.key_type)
# n, e, d, etc. are the names used in mathematical proofs for the variables
# so using so short names makes it actually more readable
# pylint: disable=invalid-name
def _createPublicRSAKey(n, e, key_type,
implementations=("openssl", "pycrypto", "python")):
for implementation in implementations:
if implementation == "openssl" and cryptomath.m2cryptoLoaded:
return OpenSSL_RSAKey(n, e, key_type=key_type)
elif implementation == "pycrypto" and cryptomath.pycryptoLoaded:
return PyCrypto_RSAKey(n, e, key_type=key_type)
elif implementation == "python":
return Python_RSAKey(n, e, key_type=key_type)
raise ValueError("No acceptable implementations")
def _createPrivateRSAKey(n, e, d, p, q, dP, dQ, qInv, key_type,
implementations=("pycrypto", "python")):
for implementation in implementations:
if implementation == "pycrypto" and cryptomath.pycryptoLoaded:
return PyCrypto_RSAKey(n, e, d, p, q, dP, dQ, qInv,
key_type=key_type)
elif implementation == "python":
return Python_RSAKey(n, e, d, p, q, dP, dQ, qInv,
key_type=key_type)
raise ValueError("No acceptable implementations")
# pylint: enable=invalid-name
def _create_public_ecdsa_key(point_x, point_y, curve_name,
implementations=("python",)):
"""
Convert public key parameters into concrete implementation of verifier.
The public key in ECDSA is a point on elliptic curve, so it consists of
two integers that identify the point and the name of the curve on which
it needs to lie on.
:type point_x: int
:param point_x: the 'x' coordinate of the point
:type point_y: int
:param point_y: the 'y' coordinate of the point
:type curve_name: str
:param curve_name: well known name of the curve (e.g. 'NIST256p' or
'SECP256k1')
:type implementations: iterable of str
:param implementations: list of implementations that can be used as the
concrete implementation of the verifying key (only 'python' is
supported currently)
"""
for impl in implementations:
if impl == "python":
return Python_ECDSAKey(point_x, point_y, curve_name)
raise ValueError("No acceptable implementation")
def _create_public_eddsa_key(public_key,
implementations=("python",)):
"""
Convert the python-ecdsa public key into concrete implementation of
verifier.
"""
for impl in implementations:
if impl == "python":
return Python_EdDSAKey(public_key)
raise ValueError("No acceptable implementation")
def _create_public_dsa_key(p, q, g, y,
implementations=("python",)):
"""
Convert public key parameters into concrete implementation of verifier.
The public key in DSA consists of four integers.
:type p: int
:param p: domain parameter, prime num defining Gaolis Field
:type q: int
:param q: domain parameter, prime factor of p-1
:type g: int
:param g: domain parameter, generator of q-order cyclic group GP(p)
:type y: int
:param y: public key
:type implementations: iterable of str
:param implementations: list of implementations that can be used as the
concrete implementation of the verifying key (only 'python' is
supported currently)
"""
for impl in implementations:
if impl == "python":
return Python_DSAKey(p=p, q=q, g=g, y=y)
raise ValueError("No acceptable implementation")