diff options
Diffstat (limited to 'cryptography/hazmat')
| -rw-r--r-- | cryptography/hazmat/primitives/ciphers/base.py | 3 | ||||
| -rw-r--r-- | cryptography/hazmat/primitives/ciphers/modes.py | 27 | ||||
| -rw-r--r-- | cryptography/hazmat/primitives/interfaces.py | 7 |
3 files changed, 37 insertions, 0 deletions
diff --git a/cryptography/hazmat/primitives/ciphers/base.py b/cryptography/hazmat/primitives/ciphers/base.py index b8615cb9..a5603ab5 100644 --- a/cryptography/hazmat/primitives/ciphers/base.py +++ b/cryptography/hazmat/primitives/ciphers/base.py @@ -25,6 +25,9 @@ class Cipher(object): if not isinstance(algorithm, interfaces.CipherAlgorithm): raise TypeError("Expected interface of interfaces.CipherAlgorithm") + if mode is not None: + mode.validate_for_algorithm(algorithm) + self.algorithm = algorithm self.mode = mode self._backend = backend diff --git a/cryptography/hazmat/primitives/ciphers/modes.py b/cryptography/hazmat/primitives/ciphers/modes.py index e1c70185..63a69ac4 100644 --- a/cryptography/hazmat/primitives/ciphers/modes.py +++ b/cryptography/hazmat/primitives/ciphers/modes.py @@ -25,11 +25,20 @@ class CBC(object): def __init__(self, initialization_vector): self.initialization_vector = initialization_vector + def validate_for_algorithm(self, algorithm): + if len(self.initialization_vector) * 8 != algorithm.block_size: + raise ValueError("Invalid iv size ({0}) for {1}".format( + len(self.initialization_vector), self.name + )) + @utils.register_interface(interfaces.Mode) class ECB(object): name = "ECB" + def validate_for_algorithm(self, algorithm): + pass + @utils.register_interface(interfaces.Mode) @utils.register_interface(interfaces.ModeWithInitializationVector) @@ -39,6 +48,12 @@ class OFB(object): def __init__(self, initialization_vector): self.initialization_vector = initialization_vector + def validate_for_algorithm(self, algorithm): + if len(self.initialization_vector) * 8 != algorithm.block_size: + raise ValueError("Invalid iv size ({0}) for {1}".format( + len(self.initialization_vector), self.name + )) + @utils.register_interface(interfaces.Mode) @utils.register_interface(interfaces.ModeWithInitializationVector) @@ -48,6 +63,12 @@ class CFB(object): def __init__(self, initialization_vector): self.initialization_vector = initialization_vector + def validate_for_algorithm(self, algorithm): + if len(self.initialization_vector) * 8 != algorithm.block_size: + raise ValueError("Invalid iv size ({0}) for {1}".format( + len(self.initialization_vector), self.name + )) + @utils.register_interface(interfaces.Mode) @utils.register_interface(interfaces.ModeWithNonce) @@ -57,6 +78,12 @@ class CTR(object): def __init__(self, nonce): self.nonce = nonce + def validate_for_algorithm(self, algorithm): + if len(self.nonce) * 8 != algorithm.block_size: + raise ValueError("Invalid nonce size ({0}) for {1}".format( + len(self.nonce), self.name + )) + @utils.register_interface(interfaces.Mode) @utils.register_interface(interfaces.ModeWithInitializationVector) diff --git a/cryptography/hazmat/primitives/interfaces.py b/cryptography/hazmat/primitives/interfaces.py index e3f4f586..feab316b 100644 --- a/cryptography/hazmat/primitives/interfaces.py +++ b/cryptography/hazmat/primitives/interfaces.py @@ -39,6 +39,13 @@ class Mode(six.with_metaclass(abc.ABCMeta)): A string naming this mode. (e.g. ECB, CBC) """ + @abc.abstractmethod + def validate_for_algorithm(self, algorithm): + """ + Checks that all the necessary invariants of this (mode, algorithm) + combination are met. + """ + class ModeWithInitializationVector(six.with_metaclass(abc.ABCMeta)): @abc.abstractproperty |