src/cryptography/hazmat/primitives/asymmetric/rsa.py - platform/external/python/cryptography - Git at Google

 # This file is dual licensed under the terms of the Apache License, Version
 # 2.0, and the BSD License. See the LICENSE file in the root of this repository
 # for complete details.

 from __future__ import absolute_import, division, print_function

 import abc
 try:
     # Only available in math in 3.5+
     from math import gcd
 except ImportError:
     from fractions import gcd

 import six

 from cryptography import utils
 from cryptography.exceptions import UnsupportedAlgorithm, _Reasons
 from cryptography.hazmat.backends.interfaces import RSABackend


 @six.add_metaclass(abc.ABCMeta)
 class RSAPrivateKey(object):
     @abc.abstractmethod
     def signer(self, padding, algorithm):
         """
         Returns an AsymmetricSignatureContext used for signing data.
         """

     @abc.abstractmethod
     def decrypt(self, ciphertext, padding):
         """
         Decrypts the provided ciphertext.
         """

     @abc.abstractproperty
     def key_size(self):
         """
         The bit length of the public modulus.
         """

     @abc.abstractmethod
     def public_key(self):
         """
         The RSAPublicKey associated with this private key.
         """

     @abc.abstractmethod
     def sign(self, data, padding, algorithm):
         """
         Signs the data.
         """


 @six.add_metaclass(abc.ABCMeta)
 class RSAPrivateKeyWithSerialization(RSAPrivateKey):
     @abc.abstractmethod
     def private_numbers(self):
         """
         Returns an RSAPrivateNumbers.
         """

     @abc.abstractmethod
     def private_bytes(self, encoding, format, encryption_algorithm):
         """
         Returns the key serialized as bytes.
         """


 @six.add_metaclass(abc.ABCMeta)
 class RSAPublicKey(object):
     @abc.abstractmethod
     def verifier(self, signature, padding, algorithm):
         """
         Returns an AsymmetricVerificationContext used for verifying signatures.
         """

     @abc.abstractmethod
     def encrypt(self, plaintext, padding):
         """
         Encrypts the given plaintext.
         """

     @abc.abstractproperty
     def key_size(self):
         """
         The bit length of the public modulus.
         """

     @abc.abstractmethod
     def public_numbers(self):
         """
         Returns an RSAPublicNumbers
         """

     @abc.abstractmethod
     def public_bytes(self, encoding, format):
         """
         Returns the key serialized as bytes.
         """

     @abc.abstractmethod
     def verify(self, signature, data, padding, algorithm):
         """
         Verifies the signature of the data.
         """


 RSAPublicKeyWithSerialization = RSAPublicKey


 def generate_private_key(public_exponent, key_size, backend):
     if not isinstance(backend, RSABackend):
         raise UnsupportedAlgorithm(
             "Backend object does not implement RSABackend.",
             _Reasons.BACKEND_MISSING_INTERFACE
         )

     _verify_rsa_parameters(public_exponent, key_size)
     return backend.generate_rsa_private_key(public_exponent, key_size)


 def _verify_rsa_parameters(public_exponent, key_size):
     if public_exponent < 3:
         raise ValueError("public_exponent must be >= 3.")

     if public_exponent & 1 == 0:
         raise ValueError("public_exponent must be odd.")

     if key_size < 512:
         raise ValueError("key_size must be at least 512-bits.")


 def _check_private_key_components(p, q, private_exponent, dmp1, dmq1, iqmp,
                                   public_exponent, modulus):
     if modulus < 3:
         raise ValueError("modulus must be >= 3.")

     if p >= modulus:
         raise ValueError("p must be < modulus.")

     if q >= modulus:
         raise ValueError("q must be < modulus.")

     if dmp1 >= modulus:
         raise ValueError("dmp1 must be < modulus.")

     if dmq1 >= modulus:
         raise ValueError("dmq1 must be < modulus.")

     if iqmp >= modulus:
         raise ValueError("iqmp must be < modulus.")

     if private_exponent >= modulus:
         raise ValueError("private_exponent must be < modulus.")

     if public_exponent < 3 or public_exponent >= modulus:
         raise ValueError("public_exponent must be >= 3 and < modulus.")

     if public_exponent & 1 == 0:
         raise ValueError("public_exponent must be odd.")

     if dmp1 & 1 == 0:
         raise ValueError("dmp1 must be odd.")

     if dmq1 & 1 == 0:
         raise ValueError("dmq1 must be odd.")

     if p * q != modulus:
         raise ValueError("p*q must equal modulus.")


 def _check_public_key_components(e, n):
     if n < 3:
         raise ValueError("n must be >= 3.")

     if e < 3 or e >= n:
         raise ValueError("e must be >= 3 and < n.")

     if e & 1 == 0:
         raise ValueError("e must be odd.")


 def _modinv(e, m):
     """
     Modular Multiplicative Inverse. Returns x such that: (x*e) mod m == 1
     """
     x1, y1, x2, y2 = 1, 0, 0, 1
     a, b = e, m
     while b > 0:
         q, r = divmod(a, b)
         xn, yn = x1 - q * x2, y1 - q * y2
         a, b, x1, y1, x2, y2 = b, r, x2, y2, xn, yn
     return x1 % m


 def rsa_crt_iqmp(p, q):
     """
     Compute the CRT (q ** -1) % p value from RSA primes p and q.
     """
     return _modinv(q, p)


 def rsa_crt_dmp1(private_exponent, p):
     """
     Compute the CRT private_exponent % (p - 1) value from the RSA
     private_exponent (d) and p.
     """
     return private_exponent % (p - 1)


 def rsa_crt_dmq1(private_exponent, q):
     """
     Compute the CRT private_exponent % (q - 1) value from the RSA
     private_exponent (d) and q.
     """
     return private_exponent % (q - 1)


 # Controls the number of iterations rsa_recover_prime_factors will perform
 # to obtain the prime factors. Each iteration increments by 2 so the actual
 # maximum attempts is half this number.
 _MAX_RECOVERY_ATTEMPTS = 1000


 def rsa_recover_prime_factors(n, e, d):
     """
     Compute factors p and q from the private exponent d. We assume that n has
     no more than two factors. This function is adapted from code in PyCrypto.
     """
     # See 8.2.2(i) in Handbook of Applied Cryptography.
     ktot = d * e - 1
     # The quantity d*e-1 is a multiple of phi(n), even,
     # and can be represented as t*2^s.
     t = ktot
     while t % 2 == 0:
         t = t // 2
     # Cycle through all multiplicative inverses in Zn.
     # The algorithm is non-deterministic, but there is a 50% chance
     # any candidate a leads to successful factoring.
     # See "Digitalized Signatures and Public Key Functions as Intractable
     # as Factorization", M. Rabin, 1979
     spotted = False
     a = 2
     while not spotted and a < _MAX_RECOVERY_ATTEMPTS:
         k = t
         # Cycle through all values a^{t*2^i}=a^k
         while k < ktot:
             cand = pow(a, k, n)
             # Check if a^k is a non-trivial root of unity (mod n)
             if cand != 1 and cand != (n - 1) and pow(cand, 2, n) == 1:
                 # We have found a number such that (cand-1)(cand+1)=0 (mod n).
                 # Either of the terms divides n.
                 p = gcd(cand + 1, n)
                 spotted = True
                 break
             k *= 2
         # This value was not any good... let's try another!
         a += 2
     if not spotted:
         raise ValueError("Unable to compute factors p and q from exponent d.")
     # Found !
     q, r = divmod(n, p)
     assert r == 0
     p, q = sorted((p, q), reverse=True)
     return (p, q)


 class RSAPrivateNumbers(object):
     def __init__(self, p, q, d, dmp1, dmq1, iqmp,
                  public_numbers):
         if (
             not isinstance(p, six.integer_types) or
             not isinstance(q, six.integer_types) or
             not isinstance(d, six.integer_types) or
             not isinstance(dmp1, six.integer_types) or
             not isinstance(dmq1, six.integer_types) or
             not isinstance(iqmp, six.integer_types)
         ):
             raise TypeError(
                 "RSAPrivateNumbers p, q, d, dmp1, dmq1, iqmp arguments must"
                 " all be an integers."
             )

         if not isinstance(public_numbers, RSAPublicNumbers):
             raise TypeError(
                 "RSAPrivateNumbers public_numbers must be an RSAPublicNumbers"
                 " instance."
             )

         self._p = p
         self._q = q
         self._d = d
         self._dmp1 = dmp1
         self._dmq1 = dmq1
         self._iqmp = iqmp
         self._public_numbers = public_numbers

     p = utils.read_only_property("_p")
     q = utils.read_only_property("_q")
     d = utils.read_only_property("_d")
     dmp1 = utils.read_only_property("_dmp1")
     dmq1 = utils.read_only_property("_dmq1")
     iqmp = utils.read_only_property("_iqmp")
     public_numbers = utils.read_only_property("_public_numbers")

     def private_key(self, backend):
         return backend.load_rsa_private_numbers(self)

     def __eq__(self, other):
         if not isinstance(other, RSAPrivateNumbers):
             return NotImplemented

         return (
             self.p == other.p and
             self.q == other.q and
             self.d == other.d and
             self.dmp1 == other.dmp1 and
             self.dmq1 == other.dmq1 and
             self.iqmp == other.iqmp and
             self.public_numbers == other.public_numbers
         )

     def __ne__(self, other):
         return not self == other

     def __hash__(self):
         return hash((
             self.p,
             self.q,
             self.d,
             self.dmp1,
             self.dmq1,
             self.iqmp,
             self.public_numbers,
         ))


 class RSAPublicNumbers(object):
     def __init__(self, e, n):
         if (
             not isinstance(e, six.integer_types) or
             not isinstance(n, six.integer_types)
         ):
             raise TypeError("RSAPublicNumbers arguments must be integers.")

         self._e = e
         self._n = n

     e = utils.read_only_property("_e")
     n = utils.read_only_property("_n")

     def public_key(self, backend):
         return backend.load_rsa_public_numbers(self)

     def __repr__(self):
         return "<RSAPublicNumbers(e={0.e}, n={0.n})>".format(self)

     def __eq__(self, other):
         if not isinstance(other, RSAPublicNumbers):
             return NotImplemented

         return self.e == other.e and self.n == other.n

     def __ne__(self, other):
         return not self == other

     def __hash__(self):
         return hash((self.e, self.n))
	# This file is dual licensed under the terms of the Apache License, Version
	# 2.0, and the BSD License. See the LICENSE file in the root of this repository
	# for complete details.

	from __future__ import absolute_import, division, print_function

	import abc
	try:
	# Only available in math in 3.5+
	from math import gcd
	except ImportError:
	from fractions import gcd

	import six

	from cryptography import utils
	from cryptography.exceptions import UnsupportedAlgorithm, _Reasons
	from cryptography.hazmat.backends.interfaces import RSABackend


	@six.add_metaclass(abc.ABCMeta)
	class RSAPrivateKey(object):
	@abc.abstractmethod
	def signer(self, padding, algorithm):
	"""
	Returns an AsymmetricSignatureContext used for signing data.
	"""

	@abc.abstractmethod
	def decrypt(self, ciphertext, padding):
	"""
	Decrypts the provided ciphertext.
	"""

	@abc.abstractproperty
	def key_size(self):
	"""
	The bit length of the public modulus.
	"""

	@abc.abstractmethod
	def public_key(self):
	"""
	The RSAPublicKey associated with this private key.
	"""

	@abc.abstractmethod
	def sign(self, data, padding, algorithm):
	"""
	Signs the data.
	"""


	@six.add_metaclass(abc.ABCMeta)
	class RSAPrivateKeyWithSerialization(RSAPrivateKey):
	@abc.abstractmethod
	def private_numbers(self):
	"""
	Returns an RSAPrivateNumbers.
	"""

	@abc.abstractmethod
	def private_bytes(self, encoding, format, encryption_algorithm):
	"""
	Returns the key serialized as bytes.
	"""


	@six.add_metaclass(abc.ABCMeta)
	class RSAPublicKey(object):
	@abc.abstractmethod
	def verifier(self, signature, padding, algorithm):
	"""
	Returns an AsymmetricVerificationContext used for verifying signatures.
	"""

	@abc.abstractmethod
	def encrypt(self, plaintext, padding):
	"""
	Encrypts the given plaintext.
	"""

	@abc.abstractproperty
	def key_size(self):
	"""
	The bit length of the public modulus.
	"""

	@abc.abstractmethod
	def public_numbers(self):
	"""
	Returns an RSAPublicNumbers
	"""

	@abc.abstractmethod
	def public_bytes(self, encoding, format):
	"""
	Returns the key serialized as bytes.
	"""

	@abc.abstractmethod
	def verify(self, signature, data, padding, algorithm):
	"""
	Verifies the signature of the data.
	"""


	RSAPublicKeyWithSerialization = RSAPublicKey


	def generate_private_key(public_exponent, key_size, backend):
	if not isinstance(backend, RSABackend):
	raise UnsupportedAlgorithm(
	"Backend object does not implement RSABackend.",
	_Reasons.BACKEND_MISSING_INTERFACE
	)

	_verify_rsa_parameters(public_exponent, key_size)
	return backend.generate_rsa_private_key(public_exponent, key_size)


	def _verify_rsa_parameters(public_exponent, key_size):
	if public_exponent < 3:
	raise ValueError("public_exponent must be >= 3.")

	if public_exponent & 1 == 0:
	raise ValueError("public_exponent must be odd.")

	if key_size < 512:
	raise ValueError("key_size must be at least 512-bits.")


	def _check_private_key_components(p, q, private_exponent, dmp1, dmq1, iqmp,
	public_exponent, modulus):
	if modulus < 3:
	raise ValueError("modulus must be >= 3.")

	if p >= modulus:
	raise ValueError("p must be < modulus.")

	if q >= modulus:
	raise ValueError("q must be < modulus.")

	if dmp1 >= modulus:
	raise ValueError("dmp1 must be < modulus.")

	if dmq1 >= modulus:
	raise ValueError("dmq1 must be < modulus.")

	if iqmp >= modulus:
	raise ValueError("iqmp must be < modulus.")

	if private_exponent >= modulus:
	raise ValueError("private_exponent must be < modulus.")

	if public_exponent < 3 or public_exponent >= modulus:
	raise ValueError("public_exponent must be >= 3 and < modulus.")

	if public_exponent & 1 == 0:
	raise ValueError("public_exponent must be odd.")

	if dmp1 & 1 == 0:
	raise ValueError("dmp1 must be odd.")

	if dmq1 & 1 == 0:
	raise ValueError("dmq1 must be odd.")

	if p * q != modulus:
	raise ValueError("p*q must equal modulus.")


	def _check_public_key_components(e, n):
	if n < 3:
	raise ValueError("n must be >= 3.")

	if e < 3 or e >= n:
	raise ValueError("e must be >= 3 and < n.")

	if e & 1 == 0:
	raise ValueError("e must be odd.")


	def _modinv(e, m):
	"""
	Modular Multiplicative Inverse. Returns x such that: (x*e) mod m == 1
	"""
	x1, y1, x2, y2 = 1, 0, 0, 1
	a, b = e, m
	while b > 0:
	q, r = divmod(a, b)
	xn, yn = x1 - q * x2, y1 - q * y2
	a, b, x1, y1, x2, y2 = b, r, x2, y2, xn, yn
	return x1 % m


	def rsa_crt_iqmp(p, q):
	"""
	Compute the CRT (q ** -1) % p value from RSA primes p and q.
	"""
	return _modinv(q, p)


	def rsa_crt_dmp1(private_exponent, p):
	"""
	Compute the CRT private_exponent % (p - 1) value from the RSA
	private_exponent (d) and p.
	"""
	return private_exponent % (p - 1)


	def rsa_crt_dmq1(private_exponent, q):
	"""
	Compute the CRT private_exponent % (q - 1) value from the RSA
	private_exponent (d) and q.
	"""
	return private_exponent % (q - 1)


	# Controls the number of iterations rsa_recover_prime_factors will perform
	# to obtain the prime factors. Each iteration increments by 2 so the actual
	# maximum attempts is half this number.
	_MAX_RECOVERY_ATTEMPTS = 1000


	def rsa_recover_prime_factors(n, e, d):
	"""
	Compute factors p and q from the private exponent d. We assume that n has
	no more than two factors. This function is adapted from code in PyCrypto.
	"""
	# See 8.2.2(i) in Handbook of Applied Cryptography.
	ktot = d * e - 1
	# The quantity d*e-1 is a multiple of phi(n), even,
	# and can be represented as t*2^s.
	t = ktot
	while t % 2 == 0:
	t = t // 2
	# Cycle through all multiplicative inverses in Zn.
	# The algorithm is non-deterministic, but there is a 50% chance
	# any candidate a leads to successful factoring.
	# See "Digitalized Signatures and Public Key Functions as Intractable
	# as Factorization", M. Rabin, 1979
	spotted = False
	a = 2
	while not spotted and a < _MAX_RECOVERY_ATTEMPTS:
	k = t
	# Cycle through all values a^{t*2^i}=a^k
	while k < ktot:
	cand = pow(a, k, n)
	# Check if a^k is a non-trivial root of unity (mod n)
	if cand != 1 and cand != (n - 1) and pow(cand, 2, n) == 1:
	# We have found a number such that (cand-1)(cand+1)=0 (mod n).
	# Either of the terms divides n.
	p = gcd(cand + 1, n)
	spotted = True
	break
	k *= 2
	# This value was not any good... let's try another!
	a += 2
	if not spotted:
	raise ValueError("Unable to compute factors p and q from exponent d.")
	# Found !
	q, r = divmod(n, p)
	assert r == 0
	p, q = sorted((p, q), reverse=True)
	return (p, q)


	class RSAPrivateNumbers(object):
	def __init__(self, p, q, d, dmp1, dmq1, iqmp,
	public_numbers):
	if (
	not isinstance(p, six.integer_types) or
	not isinstance(q, six.integer_types) or
	not isinstance(d, six.integer_types) or
	not isinstance(dmp1, six.integer_types) or
	not isinstance(dmq1, six.integer_types) or
	not isinstance(iqmp, six.integer_types)
	):
	raise TypeError(
	"RSAPrivateNumbers p, q, d, dmp1, dmq1, iqmp arguments must"
	" all be an integers."
	)

	if not isinstance(public_numbers, RSAPublicNumbers):
	raise TypeError(
	"RSAPrivateNumbers public_numbers must be an RSAPublicNumbers"
	" instance."
	)

	self._p = p
	self._q = q
	self._d = d
	self._dmp1 = dmp1
	self._dmq1 = dmq1
	self._iqmp = iqmp
	self._public_numbers = public_numbers

	p = utils.read_only_property("_p")
	q = utils.read_only_property("_q")
	d = utils.read_only_property("_d")
	dmp1 = utils.read_only_property("_dmp1")
	dmq1 = utils.read_only_property("_dmq1")
	iqmp = utils.read_only_property("_iqmp")
	public_numbers = utils.read_only_property("_public_numbers")

	def private_key(self, backend):
	return backend.load_rsa_private_numbers(self)

	def __eq__(self, other):
	if not isinstance(other, RSAPrivateNumbers):
	return NotImplemented

	return (
	self.p == other.p and
	self.q == other.q and
	self.d == other.d and
	self.dmp1 == other.dmp1 and
	self.dmq1 == other.dmq1 and
	self.iqmp == other.iqmp and
	self.public_numbers == other.public_numbers
	)

	def __ne__(self, other):
	return not self == other

	def __hash__(self):
	return hash((
	self.p,
	self.q,
	self.d,
	self.dmp1,
	self.dmq1,
	self.iqmp,
	self.public_numbers,
	))


	class RSAPublicNumbers(object):
	def __init__(self, e, n):
	if (
	not isinstance(e, six.integer_types) or
	not isinstance(n, six.integer_types)
	):
	raise TypeError("RSAPublicNumbers arguments must be integers.")

	self._e = e
	self._n = n

	e = utils.read_only_property("_e")
	n = utils.read_only_property("_n")

	def public_key(self, backend):
	return backend.load_rsa_public_numbers(self)

	def __repr__(self):
	return "<RSAPublicNumbers(e={0.e}, n={0.n})>".format(self)

	def __eq__(self, other):
	if not isinstance(other, RSAPublicNumbers):
	return NotImplemented

	return self.e == other.e and self.n == other.n

	def __ne__(self, other):
	return not self == other

	def __hash__(self):
	return hash((self.e, self.n))