diff options
Diffstat (limited to 'docs/hazmat/backends')
-rw-r--r-- | docs/hazmat/backends/commoncrypto.rst | 11 | ||||
-rw-r--r-- | docs/hazmat/backends/interfaces.rst | 49 | ||||
-rw-r--r-- | docs/hazmat/backends/openssl.rst | 36 |
3 files changed, 64 insertions, 32 deletions
diff --git a/docs/hazmat/backends/commoncrypto.rst b/docs/hazmat/backends/commoncrypto.rst index af2032b6..16a61337 100644 --- a/docs/hazmat/backends/commoncrypto.rst +++ b/docs/hazmat/backends/commoncrypto.rst @@ -11,7 +11,16 @@ The `CommonCrypto`_ C library provided by Apple on OS X and iOS. .. data:: cryptography.hazmat.backends.commoncrypto.backend - This is the exposed API for the CommonCrypto backend. It has one public attribute. + This is the exposed API for the CommonCrypto backend. + + It implements the following interfaces: + + * :class:`~cryptography.hazmat.backends.interfaces.CipherBackend` + * :class:`~cryptography.hazmat.backends.interfaces.HashBackend` + * :class:`~cryptography.hazmat.backends.interfaces.HMACBackend` + * :class:`~cryptography.hazmat.backends.interfaces.PBKDF2HMACBackend` + + It has one additional public attribute. .. attribute:: name diff --git a/docs/hazmat/backends/interfaces.rst b/docs/hazmat/backends/interfaces.rst index 11e2f2a2..49e4c88c 100644 --- a/docs/hazmat/backends/interfaces.rst +++ b/docs/hazmat/backends/interfaces.rst @@ -37,7 +37,7 @@ A specific ``backend`` may provide one or more of these interfaces. .. method:: create_symmetric_encryption_ctx(cipher, mode) Create a - :class:`~cryptogrpahy.hazmat.primitives.interfaces.CipherContext` that + :class:`~cryptography.hazmat.primitives.interfaces.CipherContext` that can be used for encrypting data with the symmetric ``cipher`` using the given ``mode``. @@ -56,7 +56,7 @@ A specific ``backend`` may provide one or more of these interfaces. .. method:: create_symmetric_decryption_ctx(cipher, mode) Create a - :class:`~cryptogrpahy.hazmat.primitives.interfaces.CipherContext` that + :class:`~cryptography.hazmat.primitives.interfaces.CipherContext` that can be used for decrypting data with the symmetric ``cipher`` using the given ``mode``. @@ -91,7 +91,7 @@ A specific ``backend`` may provide one or more of these interfaces. .. method:: create_hash_ctx(algorithm) Create a - :class:`~cryptogrpahy.hazmat.primitives.interfaces.HashContext` that + :class:`~cryptography.hazmat.primitives.interfaces.HashContext` that uses the specified ``algorithm`` to calculate a message digest. :param algorithm: An instance of a @@ -121,7 +121,7 @@ A specific ``backend`` may provide one or more of these interfaces. .. method:: create_hmac_ctx(algorithm) Create a - :class:`~cryptogrpahy.hazmat.primitives.interfaces.HashContext` that + :class:`~cryptography.hazmat.primitives.interfaces.HashContext` that uses the specified ``algorithm`` to calculate a hash-based message authentication code. @@ -131,3 +131,44 @@ A specific ``backend`` may provide one or more of these interfaces. :returns: :class:`~cryptography.hazmat.primitives.interfaces.HashContext` + + +.. class:: PBKDF2HMACBackend + + .. versionadded:: 0.2 + + A backend with methods for using PBKDF2 using HMAC as a PRF. + + .. method:: pbkdf2_hmac_supported(algorithm) + + Check if the specified ``algorithm`` is supported by this backend. + + :param algorithm: An instance of a + :class:`~cryptography.hazmat.primitives.interfaces.HashAlgorithm` + provider. + + :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 a + :class:`~cryptography.hazmat.primitives.interfaces.HashAlgorithm` + provider. + + :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. + diff --git a/docs/hazmat/backends/openssl.rst b/docs/hazmat/backends/openssl.rst index a1f2d28a..4db3972d 100644 --- a/docs/hazmat/backends/openssl.rst +++ b/docs/hazmat/backends/openssl.rst @@ -7,37 +7,19 @@ The `OpenSSL`_ C library. .. data:: cryptography.hazmat.backends.openssl.backend - This is the exposed API for the OpenSSL backend. It has one public attribute. + This is the exposed API for the OpenSSL backend. - .. attribute:: name - - The string name of this backend: ``"openssl"`` - -Using your own OpenSSL on Linux -------------------------------- + It implements the following interfaces: -Python links to OpenSSL for its own purposes and this can sometimes cause -problems when you wish to use a different version of OpenSSL with cryptography. -If you want to use cryptography with your own build of OpenSSL you will need to -make sure that the build is configured correctly so that your version of -OpenSSL doesn't conflict with Python's. + * :class:`~cryptography.hazmat.backends.interfaces.CipherBackend` + * :class:`~cryptography.hazmat.backends.interfaces.HashBackend` + * :class:`~cryptography.hazmat.backends.interfaces.HMACBackend` + * :class:`~cryptography.hazmat.backends.interfaces.PBKDF2HMACBackend` -The options you need to add allow the linker to identify every symbol correctly -even when multiple versions of the library are linked into the same program. If -you are using your distribution's source packages these will probably be -patched in for you already, otherwise you'll need to use options something like -this when configuring OpenSSL:: + It has one additional public attribute. - ./config -Wl,--version-script=openssl.ld -Wl,-Bsymbolic-functions -fPIC shared - -You'll also need to generate your own ``openssl.ld`` file. For example:: - - OPENSSL_1.0.1F_CUSTOM { - global: - *; - }; + .. attribute:: name -You should replace the version string on the first line as appropriate for your -build. + The string name of this backend: ``"openssl"`` .. _`OpenSSL`: https://www.openssl.org/ |