From 7a2823bdffbaa60262a377ebcd2cd1bc63f4b773 Mon Sep 17 00:00:00 2001 From: Paul Kehrer Date: Thu, 4 Nov 2021 06:51:23 +0800 Subject: [PATCH] deprecate backend part 6 of n (#6524) --- CHANGELOG.rst | 24 +- docs/faq.rst | 2 +- docs/hazmat/backends/index.rst | 33 -- docs/hazmat/backends/interfaces.rst | 630 ------------------------- docs/index.rst | 2 +- docs/{hazmat/backends => }/openssl.rst | 47 +- 6 files changed, 24 insertions(+), 714 deletions(-) delete mode 100644 docs/hazmat/backends/index.rst delete mode 100644 docs/hazmat/backends/interfaces.rst rename docs/{hazmat/backends => }/openssl.rst (75%) diff --git a/CHANGELOG.rst b/CHANGELOG.rst index 415ed0f35..625cec051 100644 --- a/CHANGELOG.rst +++ b/CHANGELOG.rst @@ -1590,8 +1590,7 @@ Changelog * Deprecated ``elliptic_curve_private_key_from_numbers`` and ``elliptic_curve_public_key_from_numbers`` in favor of ``load_elliptic_curve_private_numbers`` and - ``load_elliptic_curve_public_numbers`` on - :class:`~cryptography.hazmat.backends.interfaces.EllipticCurveBackend`. + ``load_elliptic_curve_public_numbers`` on ``EllipticCurveBackend``. * Added ``EllipticCurvePrivateKeyWithNumbers`` and ``EllipticCurvePublicKeyWithNumbers`` support. * Work around three GCM related bugs in CommonCrypto and OpenSSL. @@ -1661,17 +1660,15 @@ Changelog * Added :class:`~cryptography.hazmat.primitives.ciphers.modes.CFB8` support for :class:`~cryptography.hazmat.primitives.ciphers.algorithms.AES` and :class:`~cryptography.hazmat.primitives.ciphers.algorithms.TripleDES` on - ``commoncrypto`` and :doc:`/hazmat/backends/openssl`. + ``commoncrypto`` and ``openssl``. * Added ``AES`` :class:`~cryptography.hazmat.primitives.ciphers.modes.CTR` support to the OpenSSL backend when linked against 0.9.8. * Added ``PKCS8SerializationBackend`` and - ``TraditionalOpenSSLSerializationBackend`` support to the - :doc:`/hazmat/backends/openssl`. -* Added :doc:`/hazmat/primitives/asymmetric/ec` and - :class:`~cryptography.hazmat.backends.interfaces.EllipticCurveBackend`. + ``TraditionalOpenSSLSerializationBackend`` support to ``openssl``. +* Added :doc:`/hazmat/primitives/asymmetric/ec` and ``EllipticCurveBackend``. * Added :class:`~cryptography.hazmat.primitives.ciphers.modes.ECB` support for :class:`~cryptography.hazmat.primitives.ciphers.algorithms.TripleDES` on - ``commoncrypto`` and :doc:`/hazmat/backends/openssl`. + ``commoncrypto`` and ``openssl``. * Deprecated the concrete ``RSAPrivateKey`` class in favor of backend specific providers of the :class:`cryptography.hazmat.primitives.asymmetric.rsa.RSAPrivateKey` @@ -1693,10 +1690,9 @@ Changelog :class:`cryptography.hazmat.primitives.asymmetric.dsa.DSAParameters` interface. * Deprecated ``encrypt_rsa``, ``decrypt_rsa``, ``create_rsa_signature_ctx`` and - ``create_rsa_verification_ctx`` on - :class:`~cryptography.hazmat.backends.interfaces.RSABackend`. + ``create_rsa_verification_ctx`` on ``RSABackend``. * Deprecated ``create_dsa_signature_ctx`` and ``create_dsa_verification_ctx`` - on :class:`~cryptography.hazmat.backends.interfaces.DSABackend`. + on ``DSABackend``. .. _v0-4: @@ -1763,8 +1759,7 @@ Changelog * Added ``commoncrypto``. * Added initial ``commoncrypto``. -* Removed ``register_cipher_adapter`` method from - :class:`~cryptography.hazmat.backends.interfaces.CipherBackend`. +* Removed ``register_cipher_adapter`` method from ``CipherBackend``. * Added support for the OpenSSL backend under Windows. * Improved thread-safety for the OpenSSL backend. * Fixed compilation on systems where OpenSSL's ``ec.h`` header is not @@ -1772,8 +1767,7 @@ Changelog * Added :class:`~cryptography.hazmat.primitives.kdf.pbkdf2.PBKDF2HMAC`. * Added :class:`~cryptography.hazmat.primitives.kdf.hkdf.HKDF`. * Added ``multibackend``. -* Set default random for the :doc:`/hazmat/backends/openssl` to the OS - random engine. +* Set default random for ``openssl`` to the OS random engine. * Added :class:`~cryptography.hazmat.primitives.ciphers.algorithms.CAST5` (CAST-128) support. diff --git a/docs/faq.rst b/docs/faq.rst index c3e139e6f..6249a3809 100644 --- a/docs/faq.rst +++ b/docs/faq.rst @@ -73,7 +73,7 @@ legacy libraries: Why does ``cryptography`` require Rust? --------------------------------------- -``cryptography`` uses OpenSSL for its cryptographic operations. OpenSSL is +``cryptography`` uses OpenSSL (see: :doc:`/openssl`) for its cryptographic operations. OpenSSL is the de facto standard for cryptographic libraries and provides high performance along with various certifications that may be relevant to developers. However, it is written in C and lacks `memory safety`_. We want ``cryptography`` to be diff --git a/docs/hazmat/backends/index.rst b/docs/hazmat/backends/index.rst deleted file mode 100644 index 97dbc869b..000000000 --- a/docs/hazmat/backends/index.rst +++ /dev/null @@ -1,33 +0,0 @@ -.. hazmat:: - -Backends -======== - -Getting a backend ------------------ - -.. currentmodule:: cryptography.hazmat.backends - -``cryptography`` was designed to support multiple cryptographic backends, but -consumers rarely need this flexibility. Starting with version 3.1 ``backend`` -arguments are optional and the default backend will automatically be selected -if none is specified. - -On older versions you can get the default backend by calling -:func:`~default_backend`. - - -.. function:: default_backend() - - :returns: An object that provides at least - :class:`~interfaces.CipherBackend`, :class:`~interfaces.HashBackend`, and - :class:`~interfaces.HMACBackend`. - -Individual backends -------------------- - -.. toctree:: - :maxdepth: 1 - - openssl - interfaces diff --git a/docs/hazmat/backends/interfaces.rst b/docs/hazmat/backends/interfaces.rst deleted file mode 100644 index 6c2f0aa78..000000000 --- a/docs/hazmat/backends/interfaces.rst +++ /dev/null @@ -1,630 +0,0 @@ -.. hazmat:: - -Backend interfaces -================== - -.. currentmodule:: cryptography.hazmat.backends.interfaces - - -Backend implementations may provide a number of interfaces to support -operations such as :doc:`/hazmat/primitives/symmetric-encryption`, -:doc:`/hazmat/primitives/cryptographic-hashes`, and -:doc:`/hazmat/primitives/mac/hmac`. - -A specific ``backend`` may provide one or more of these interfaces. - - -.. class:: CipherBackend - - A backend that provides methods for using ciphers for encryption - and decryption. - - The following backends implement this interface: - - * :doc:`/hazmat/backends/openssl` - - .. method:: cipher_supported(cipher, mode) - - Check if a ``cipher`` and ``mode`` combination is supported by - this backend. - - :param cipher: An instance of - :class:`~cryptography.hazmat.primitives.ciphers.CipherAlgorithm`. - - :param mode: An instance of - :class:`~cryptography.hazmat.primitives.ciphers.modes.Mode`. - - :returns: ``True`` if the specified ``cipher`` and ``mode`` combination - is supported by this backend, otherwise ``False`` - - - .. method:: create_symmetric_encryption_ctx(cipher, mode) - - Create a - :class:`~cryptography.hazmat.primitives.ciphers.CipherContext` that - can be used for encrypting data with the symmetric ``cipher`` using - the given ``mode``. - - :param cipher: An instance of - :class:`~cryptography.hazmat.primitives.ciphers.CipherAlgorithm`. - - :param mode: An instance of - :class:`~cryptography.hazmat.primitives.ciphers.modes.Mode`. - - :returns: - :class:`~cryptography.hazmat.primitives.ciphers.CipherContext` - - :raises ValueError: When tag is not None in an AEAD mode - - - .. method:: create_symmetric_decryption_ctx(cipher, mode) - - Create a - :class:`~cryptography.hazmat.primitives.ciphers.CipherContext` that - can be used for decrypting data with the symmetric ``cipher`` using - the given ``mode``. - - :param cipher: An instance of - :class:`~cryptography.hazmat.primitives.ciphers.CipherAlgorithm`. - - :param mode: An instance of - :class:`~cryptography.hazmat.primitives.ciphers.modes.Mode`. - - :returns: - :class:`~cryptography.hazmat.primitives.ciphers.CipherContext` - - :raises ValueError: When tag is None in an AEAD mode - - -.. class:: HashBackend - - A backend with methods for using cryptographic hash functions. - - The following backends implement this interface: - - * :doc:`/hazmat/backends/openssl` - - .. method:: hash_supported(algorithm) - - Check if the specified ``algorithm`` is supported by this backend. - - :param algorithm: An instance of - :class:`~cryptography.hazmat.primitives.hashes.HashAlgorithm`. - - :returns: ``True`` if the specified ``algorithm`` is supported by this - backend, otherwise ``False``. - - - .. method:: create_hash_ctx(algorithm) - - Create a - :class:`~cryptography.hazmat.primitives.hashes.HashContext` that - uses the specified ``algorithm`` to calculate a message digest. - - :param algorithm: An instance of - :class:`~cryptography.hazmat.primitives.hashes.HashAlgorithm`. - - :returns: - :class:`~cryptography.hazmat.primitives.hashes.HashContext` - - -.. class:: HMACBackend - - A backend with methods for using cryptographic hash functions as message - authentication codes. - - The following backends implement this interface: - - * :doc:`/hazmat/backends/openssl` - - .. method:: hmac_supported(algorithm) - - Check if the specified ``algorithm`` is supported by this backend. - - :param algorithm: An instance of - :class:`~cryptography.hazmat.primitives.hashes.HashAlgorithm`. - - :returns: ``True`` if the specified ``algorithm`` is supported for HMAC - by this backend, otherwise ``False``. - - .. method:: create_hmac_ctx(key, algorithm) - - Create a - :class:`~cryptography.hazmat.primitives.hashes.HashContext` that - uses the specified ``algorithm`` to calculate a hash-based message - authentication code. - - :param bytes key: Secret key as ``bytes``. - - :param algorithm: An instance of - :class:`~cryptography.hazmat.primitives.hashes.HashAlgorithm`. - - :returns: - :class:`~cryptography.hazmat.primitives.hashes.HashContext` - - -.. class:: CMACBackend - - .. versionadded:: 0.4 - - A backend with methods for using CMAC - - .. method:: cmac_algorithm_supported(algorithm) - - :param algorithm: An instance of - :class:`~cryptography.hazmat.primitives.ciphers.BlockCipherAlgorithm`. - - :return: Returns True if the block cipher is supported for CMAC by this backend - - .. method:: create_cmac_ctx(algorithm) - - Create a - context that - uses the specified ``algorithm`` to calculate a message authentication code. - - :param algorithm: An instance of - :class:`~cryptography.hazmat.primitives.ciphers.BlockCipherAlgorithm`. - - :returns: CMAC object. - - -.. class:: PBKDF2HMACBackend - - .. versionadded:: 0.2 - - A backend with methods for using PBKDF2 using HMAC as a PRF. - - The following backends implement this interface: - - * :doc:`/hazmat/backends/openssl` - - .. method:: pbkdf2_hmac_supported(algorithm) - - Check if the specified ``algorithm`` is supported by this backend. - - :param algorithm: An instance of - :class:`~cryptography.hazmat.primitives.hashes.HashAlgorithm`. - - :returns: ``True`` if the specified ``algorithm`` is supported for - PBKDF2 HMAC by this backend, otherwise ``False``. - - .. method:: derive_pbkdf2_hmac(self, algorithm, length, salt, iterations, key_material) - - :param algorithm: An instance of - :class:`~cryptography.hazmat.primitives.hashes.HashAlgorithm`. - - :param int length: The desired length of the derived key. Maximum is - (2\ :sup:`32` - 1) * ``algorithm.digest_size`` - - :param bytes salt: A salt. - - :param int iterations: The number of iterations to perform of the hash - function. This can be used to control the length of time the - operation takes. Higher numbers help mitigate brute force attacks - against derived keys. - - :param bytes key_material: The key material to use as a basis for - the derived key. This is typically a password. - - :return bytes: Derived key. - - -.. class:: RSABackend - - .. versionadded:: 0.2 - - A backend with methods for using RSA. - - .. method:: generate_rsa_private_key(public_exponent, key_size) - - :param int public_exponent: The public exponent of the new key. - Often one of the small Fermat primes 3, 5, 17, 257 or 65537. - - :param int key_size: The length in bits of the modulus. Should be - at least 2048. - - :return: A new instance of - :class:`~cryptography.hazmat.primitives.asymmetric.rsa.RSAPrivateKey`. - - :raises ValueError: If the public_exponent is not valid. - - .. method:: rsa_padding_supported(padding) - - Check if the specified ``padding`` is supported by the backend. - - :param padding: An instance of - :class:`~cryptography.hazmat.primitives.asymmetric.padding.AsymmetricPadding`. - - :returns: ``True`` if the specified ``padding`` is supported by this - backend, otherwise ``False``. - - .. method:: generate_rsa_parameters_supported(public_exponent, key_size) - - Check if the specified parameters are supported for key generation by - the backend. - - :param int public_exponent: The public exponent. - - :param int key_size: The bit length of the generated modulus. - - .. method:: load_rsa_private_numbers(numbers) - - :param numbers: An instance of - :class:`~cryptography.hazmat.primitives.asymmetric.rsa.RSAPrivateNumbers`. - - :returns: An instance of - :class:`~cryptography.hazmat.primitives.asymmetric.rsa.RSAPrivateKey`. - - :raises ValueError: This is raised when the values of ``p``, ``q``, - ``private_exponent``, ``public_exponent``, or ``modulus`` do not - match the bounds specified in :rfc:`3447`. - - :raises cryptography.exceptions.UnsupportedAlgorithm: This is raised - when any backend specific criteria are not met. - - .. method:: load_rsa_public_numbers(numbers) - - :param numbers: An instance of - :class:`~cryptography.hazmat.primitives.asymmetric.rsa.RSAPublicNumbers`. - - :returns: An instance of - :class:`~cryptography.hazmat.primitives.asymmetric.rsa.RSAPublicKey`. - - :raises ValueError: This is raised when the values of - ``public_exponent`` or ``modulus`` do not match the bounds - specified in :rfc:`3447`. - - :raises cryptography.exceptions.UnsupportedAlgorithm: This is raised - when any backend specific criteria are not met. - - -.. class:: DSABackend - - .. versionadded:: 0.4 - - A backend with methods for using DSA. - - .. method:: generate_dsa_parameters(key_size) - - :param int key_size: The length of the modulus in bits. It should be - either 1024, 2048 or 3072. For keys generated in 2015 this should - be at least 2048. - Note that some applications (such as SSH) have not yet gained - support for larger key sizes specified in FIPS 186-3 and are still - restricted to only the 1024-bit keys specified in FIPS 186-2. - - :return: A new instance of - :class:`~cryptography.hazmat.primitives.asymmetric.dsa.DSAParameters`. - - .. method:: generate_dsa_private_key(parameters) - - :param parameters: An instance of - :class:`~cryptography.hazmat.primitives.asymmetric.dsa.DSAParameters`. - - :return: A new instance of - :class:`~cryptography.hazmat.primitives.asymmetric.dsa.DSAPrivateKey`. - - :raises ValueError: This is raised if the key size is not one of 1024, - 2048, or 3072. - - .. method:: generate_dsa_private_key_and_parameters(key_size) - - :param int key_size: The length of the modulus in bits. It should be - either 1024, 2048 or 3072. For keys generated in 2015 this should - be at least 2048. - Note that some applications (such as SSH) have not yet gained - support for larger key sizes specified in FIPS 186-3 and are still - restricted to only the 1024-bit keys specified in FIPS 186-2. - - :return: A new instance of - :class:`~cryptography.hazmat.primitives.asymmetric.dsa.DSAPrivateKey`. - - :raises ValueError: This is raised if the key size is not supported - by the backend. - - .. method:: dsa_hash_supported(algorithm) - - :param algorithm: An instance of - :class:`~cryptography.hazmat.primitives.hashes.HashAlgorithm`. - - :returns: ``True`` if the specified ``algorithm`` is supported by this - backend, otherwise ``False``. - - .. method:: dsa_parameters_supported(p, q, g) - - :param int p: The p value of a DSA key. - - :param int q: The q value of a DSA key. - - :param int g: The g value of a DSA key. - - :returns: ``True`` if the given values of ``p``, ``q``, and ``g`` are - supported by this backend, otherwise ``False``. - - .. method:: load_dsa_parameter_numbers(numbers) - - :param numbers: An instance of - :class:`~cryptography.hazmat.primitives.asymmetric.dsa.DSAParameterNumbers`. - - :returns: An instance of - :class:`~cryptography.hazmat.primitives.asymmetric.dsa.DSAParameters`. - - :raises cryptography.exceptions.UnsupportedAlgorithm: This is raised - when any backend specific criteria are not met. - - .. method:: load_dsa_private_numbers(numbers) - - :param numbers: An instance of - :class:`~cryptography.hazmat.primitives.asymmetric.dsa.DSAPrivateNumbers`. - - :returns: An instance of - :class:`~cryptography.hazmat.primitives.asymmetric.dsa.DSAPrivateKey`. - - :raises cryptography.exceptions.UnsupportedAlgorithm: This is raised - when any backend specific criteria are not met. - - .. method:: load_dsa_public_numbers(numbers) - - :param numbers: An instance of - :class:`~cryptography.hazmat.primitives.asymmetric.dsa.DSAPublicNumbers`. - - :returns: An instance of - :class:`~cryptography.hazmat.primitives.asymmetric.dsa.DSAPublicKey`. - - :raises cryptography.exceptions.UnsupportedAlgorithm: This is raised - when any backend specific criteria are not met. - - -.. class:: EllipticCurveBackend - - .. versionadded:: 0.5 - - .. method:: elliptic_curve_supported(curve) - - :param curve: An instance of - :class:`~cryptography.hazmat.primitives.asymmetric.ec.EllipticCurve`. - - :returns: True if the elliptic curve is supported by this backend. - - .. method:: elliptic_curve_signature_algorithm_supported(signature_algorithm, curve) - - :param signature_algorithm: An instance of - :class:`~cryptography.hazmat.primitives.asymmetric.ec.EllipticCurveSignatureAlgorithm`. - - :param curve: An instance of - :class:`~cryptography.hazmat.primitives.asymmetric.ec.EllipticCurve`. - - :returns: True if the signature algorithm and curve are supported by this backend. - - .. method:: generate_elliptic_curve_private_key(curve) - - :param curve: An instance of - :class:`~cryptography.hazmat.primitives.asymmetric.ec.EllipticCurve`. - - .. method:: load_elliptic_curve_private_numbers(numbers) - - :param numbers: An instance of - :class:`~cryptography.hazmat.primitives.asymmetric.ec.EllipticCurvePrivateNumbers`. - - :returns: An instance of - :class:`~cryptography.hazmat.primitives.asymmetric.ec.EllipticCurvePrivateKey`. - - .. method:: load_elliptic_curve_public_numbers(numbers) - - :param numbers: An instance of - :class:`~cryptography.hazmat.primitives.asymmetric.ec.EllipticCurvePublicNumbers`. - - :returns: An instance of - :class:`~cryptography.hazmat.primitives.asymmetric.ec.EllipticCurvePublicKey`. - - .. method:: derive_elliptic_curve_private_key(private_value, curve) - - :param private_value: A secret scalar value. - - :param curve: An instance of - :class:`~cryptography.hazmat.primitives.asymmetric.ec.EllipticCurve`. - - :returns: An instance of - :class:`~cryptography.hazmat.primitives.asymmetric.ec.EllipticCurvePrivateKey`. - -.. class:: PEMSerializationBackend - - .. versionadded:: 0.6 - - A backend with methods for working with any PEM encoded keys. - - .. method:: load_pem_private_key(data, password) - - :param bytes data: PEM data to load. - :param bytes password: The password to use if the data is encrypted. - Should be ``None`` if the data is not encrypted. - :return: A new instance of the appropriate type of private key that the - serialized data contains. - :raises ValueError: If the data could not be deserialized. - :raises cryptography.exceptions.UnsupportedAlgorithm: If the data is - encrypted with an unsupported algorithm. - - .. method:: load_pem_public_key(data) - - :param bytes data: PEM data to load. - :return: A new instance of the appropriate type of public key - serialized data contains. - :raises ValueError: If the data could not be deserialized. - - .. method:: load_pem_parameters(data) - - .. versionadded:: 2.0 - - :param bytes data: PEM data to load. - :return: A new instance of the appropriate type of asymmetric - parameters the serialized data contains. - :raises ValueError: If the data could not be deserialized. - -.. class:: DERSerializationBackend - - .. versionadded:: 0.8 - - A backend with methods for working with DER encoded keys. - - .. method:: load_der_private_key(data, password) - - :param bytes data: DER data to load. - :param bytes password: The password to use if the data is encrypted. - Should be ``None`` if the data is not encrypted. - :return: A new instance of the appropriate type of private key that the - serialized data contains. - :raises ValueError: If the data could not be deserialized. - :raises cryptography.exceptions.UnsupportedAlgorithm: If the data is - encrypted with an unsupported algorithm. - - .. method:: load_der_public_key(data) - - :param bytes data: DER data to load. - :return: A new instance of the appropriate type of public key - serialized data contains. - :raises ValueError: If the data could not be deserialized. - - .. method:: load_der_parameters(data) - - .. versionadded:: 2.0 - - :param bytes data: DER data to load. - :return: A new instance of the appropriate type of asymmetric - parameters the serialized data contains. - :raises ValueError: If the data could not be deserialized. - - -.. class:: X509Backend - - .. versionadded:: 0.7 - - A backend with methods for working with X.509 objects. - - .. method:: create_x509_revoked_certificate(builder) - - .. versionadded:: 1.2 - - :param builder: An instance of RevokedCertificateBuilder. - - :returns: A new instance of - :class:`~cryptography.x509.RevokedCertificate`. - -.. class:: DHBackend - - .. versionadded:: 0.9 - - A backend with methods for doing Diffie-Hellman key exchange. - - .. method:: generate_dh_parameters(generator, key_size) - - :param int generator: The generator to use. Often 2 or 5. - - :param int key_size: The bit length of the prime modulus to generate. - - :return: A new instance of - :class:`~cryptography.hazmat.primitives.asymmetric.dh.DHParameters`. - - :raises ValueError: If ``key_size`` is not at least 512. - - .. method:: generate_dh_private_key(parameters) - - :param parameters: An instance of - :class:`~cryptography.hazmat.primitives.asymmetric.dh.DHParameters`. - - :return: A new instance of - :class:`~cryptography.hazmat.primitives.asymmetric.dh.DHPrivateKey`. - - .. method:: generate_dh_private_key_and_parameters(generator, key_size) - - :param int generator: The generator to use. Often 2 or 5. - - :param int key_size: The bit length of the prime modulus to generate. - - :return: A new instance of - :class:`~cryptography.hazmat.primitives.asymmetric.dh.DHPrivateKey`. - - :raises ValueError: If ``key_size`` is not at least 512. - - .. method:: load_dh_private_numbers(numbers) - - :param numbers: A - :class:`~cryptography.hazmat.primitives.asymmetric.dh.DHPrivateNumbers` - instance. - - :return: A new instance of - :class:`~cryptography.hazmat.primitives.asymmetric.dh.DHPrivateKey`. - - :raises cryptography.exceptions.UnsupportedAlgorithm: This is raised - when any backend specific criteria are not met. - - .. method:: load_dh_public_numbers(numbers) - - :param numbers: A - :class:`~cryptography.hazmat.primitives.asymmetric.dh.DHPublicNumbers` - instance. - - :return: A new instance of - :class:`~cryptography.hazmat.primitives.asymmetric.dh.DHPublicKey`. - - :raises cryptography.exceptions.UnsupportedAlgorithm: This is raised - when any backend specific criteria are not met. - - .. method:: load_dh_parameter_numbers(numbers) - - :param numbers: A - :class:`~cryptography.hazmat.primitives.asymmetric.dh.DHParameterNumbers` - instance. - - :return: A new instance of - :class:`~cryptography.hazmat.primitives.asymmetric.dh.DHParameters`. - - :raises cryptography.exceptions.UnsupportedAlgorithm: This is raised - when any backend specific criteria are not met. - - .. method:: dh_parameters_supported(p, g, q=None) - - :param int p: The p value of the DH key. - - :param int g: The g value of the DH key. - - :param int q: The q value of the DH key. - - :returns: ``True`` if the given values of ``p``, ``g`` and ``q`` - are supported by this backend, otherwise ``False``. - - .. versionadded:: 1.8 - - .. method:: dh_x942_serialization_supported() - - :returns: True if serialization of DH objects with - subgroup order (q) is supported by this backend. - - -.. class:: ScryptBackend - - .. versionadded:: 1.6 - - A backend with methods for using Scrypt. - - The following backends implement this interface: - - * :doc:`/hazmat/backends/openssl` - - .. method:: derive_scrypt(self, key_material, salt, length, n, r, p) - - :param bytes key_material: The key material to use as a basis for - the derived key. This is typically a password. - - :param bytes salt: A salt. - - :param int length: The desired length of the derived key. - - :param int n: CPU/Memory cost parameter. It must be larger than 1 and be a - power of 2. - - :param int r: Block size parameter. - - :param int p: Parallelization parameter. - - :return bytes: Derived key. - diff --git a/docs/index.rst b/docs/index.rst index 460873ccd..08fcba34d 100644 --- a/docs/index.rst +++ b/docs/index.rst @@ -67,7 +67,6 @@ hazmat layer only when necessary. hazmat/primitives/index exceptions random-numbers - hazmat/backends/index .. toctree:: :maxdepth: 2 @@ -77,6 +76,7 @@ hazmat layer only when necessary. changelog faq development/index + openssl security limitations api-stability diff --git a/docs/hazmat/backends/openssl.rst b/docs/openssl.rst similarity index 75% rename from docs/hazmat/backends/openssl.rst rename to docs/openssl.rst index dd85d869a..b628d0a94 100644 --- a/docs/hazmat/backends/openssl.rst +++ b/docs/openssl.rst @@ -1,41 +1,20 @@ -.. hazmat:: +Use of OpenSSL +============== -OpenSSL backend -=============== +``cryptography`` depends on the `OpenSSL`_ C library for all cryptographic +operation. OpenSSL is the de facto standard for cryptographic libraries and +provides high performance along with various certifications that may be +relevant to developers. -The `OpenSSL`_ C library. Cryptography supports OpenSSL version 1.1.0 and -greater. +A list of supported versions can be found in our :doc:`/installation` +documentation. + +In general the backend should be considered an internal implementation detail +of the project, but there are some public methods available for more advanced +control. .. data:: cryptography.hazmat.backends.openssl.backend - This is the exposed API for the OpenSSL backend. - - It implements the following interfaces: - - * :class:`~cryptography.hazmat.backends.interfaces.CipherBackend` - * :class:`~cryptography.hazmat.backends.interfaces.CMACBackend` - * :class:`~cryptography.hazmat.backends.interfaces.DERSerializationBackend` - * :class:`~cryptography.hazmat.backends.interfaces.DHBackend` - * :class:`~cryptography.hazmat.backends.interfaces.DSABackend` - * :class:`~cryptography.hazmat.backends.interfaces.EllipticCurveBackend` - * :class:`~cryptography.hazmat.backends.interfaces.HashBackend` - * :class:`~cryptography.hazmat.backends.interfaces.HMACBackend` - * :class:`~cryptography.hazmat.backends.interfaces.PBKDF2HMACBackend` - * :class:`~cryptography.hazmat.backends.interfaces.RSABackend` - * :class:`~cryptography.hazmat.backends.interfaces.PEMSerializationBackend` - * :class:`~cryptography.hazmat.backends.interfaces.X509Backend` - - It also implements the following interface for OpenSSL versions ``1.1.0`` - and above. - - * :class:`~cryptography.hazmat.backends.interfaces.ScryptBackend` - - It also exposes the following: - - .. attribute:: name - - The string name of this backend: ``"openssl"`` - .. method:: openssl_version_text() :return text: The friendly string name of the loaded OpenSSL library. @@ -72,7 +51,7 @@ OS random engine As of OpenSSL 1.1.1d its CSPRNG is fork-safe by default. ``cryptography`` does not compile or load the custom engine on - these versions. + >= 1.1.1d. By default OpenSSL uses a user-space CSPRNG that is seeded from system random ( ``/dev/urandom`` or ``CryptGenRandom``). This CSPRNG is not reseeded