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Diffstat (limited to 'docs/hazmat/primitives/symmetric-encryption.rst')
| -rw-r--r-- | docs/hazmat/primitives/symmetric-encryption.rst | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/docs/hazmat/primitives/symmetric-encryption.rst b/docs/hazmat/primitives/symmetric-encryption.rst index 5852dc21..c1c8d247 100644 --- a/docs/hazmat/primitives/symmetric-encryption.rst +++ b/docs/hazmat/primitives/symmetric-encryption.rst @@ -42,12 +42,21 @@ where the encrypter and decrypter both use the same key. :class:`~cryptography.hazmat.primitives.interfaces.CipherContext` provider. + If the backend doesn't support the requested combination of ``cipher`` + and ``mode`` an :class:`cryptography.exceptions.UnsupportedAlgorithm` + will be raised. + .. method:: decryptor() :return: A decrypting :class:`~cryptography.hazmat.primitives.interfaces.CipherContext` provider. + If the backend doesn't support the requested combination of ``cipher`` + and ``mode`` an :class:`cryptography.exceptions.UnsupportedAlgorithm` + will be raised. + + .. currentmodule:: cryptography.hazmat.primitives.interfaces .. class:: CipherContext @@ -63,6 +72,12 @@ where the encrypter and decrypter both use the same key. :param bytes data: The data you wish to pass into the context. :return bytes: Returns the data that was encrypted or decrypted. + When the ``BlockCipher`` was constructed in a mode turns it into a + stream cipher (e.g. + :class:`cryptography.hazmat.primitives.block.modes.CTR`), this will + return bytes immediately, however in other modes it will return chunks, + whose size is determined by the cipher's block size. + .. method:: finalize() :return bytes: Returns the remainder of the data. @@ -162,7 +177,8 @@ Modes block size of less than 128-bits. CTR (Counter) is a mode of operation for block ciphers. It is considered - cryptographically strong. + cryptographically strong. It transforms a block cipher into a stream + cipher. :param bytes nonce: Should be random bytes. It is critical to never reuse a ``nonce`` with a given key. Any reuse of a nonce |