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Diffstat (limited to 'frozen_deps/Crypto/PublicKey/pubkey.py')
| -rw-r--r-- | frozen_deps/Crypto/PublicKey/pubkey.py | 240 |
1 files changed, 240 insertions, 0 deletions
diff --git a/frozen_deps/Crypto/PublicKey/pubkey.py b/frozen_deps/Crypto/PublicKey/pubkey.py new file mode 100644 index 0000000..e46b076 --- /dev/null +++ b/frozen_deps/Crypto/PublicKey/pubkey.py @@ -0,0 +1,240 @@ +# +# pubkey.py : Internal functions for public key operations +# +# Part of the Python Cryptography Toolkit +# +# Written by Andrew Kuchling, Paul Swartz, and others +# +# =================================================================== +# The contents of this file are dedicated to the public domain. To +# the extent that dedication to the public domain is not available, +# everyone is granted a worldwide, perpetual, royalty-free, +# non-exclusive license to exercise all rights associated with the +# contents of this file for any purpose whatsoever. +# No rights are reserved. +# +# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, +# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF +# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND +# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS +# BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN +# ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN +# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE +# SOFTWARE. +# =================================================================== +# + +__revision__ = "$Id$" + +import types, warnings +from Crypto.Util.number import * + +# Basic public key class +class pubkey: + """An abstract class for a public key object. + + :undocumented: __getstate__, __setstate__, __eq__, __ne__, validate + """ + def __init__(self): + pass + + def __getstate__(self): + """To keep key objects platform-independent, the key data is + converted to standard Python long integers before being + written out. It will then be reconverted as necessary on + restoration.""" + d=self.__dict__ + for key in self.keydata: + if key in d: d[key]=int(d[key]) + return d + + def __setstate__(self, d): + """On unpickling a key object, the key data is converted to the big +number representation being used, whether that is Python long +integers, MPZ objects, or whatever.""" + for key in self.keydata: + if key in d: self.__dict__[key]=bignum(d[key]) + + def encrypt(self, plaintext, K): + """Encrypt a piece of data. + + :Parameter plaintext: The piece of data to encrypt. + :Type plaintext: byte string or long + + :Parameter K: A random parameter required by some algorithms + :Type K: byte string or long + + :Return: A tuple with two items. Each item is of the same type as the + plaintext (string or long). + """ + wasString=0 + if isinstance(plaintext, bytes): + plaintext=bytes_to_long(plaintext) ; wasString=1 + if isinstance(K, bytes): + K=bytes_to_long(K) + ciphertext=self._encrypt(plaintext, K) + if wasString: return tuple(map(long_to_bytes, ciphertext)) + else: return ciphertext + + def decrypt(self, ciphertext): + """Decrypt a piece of data. + + :Parameter ciphertext: The piece of data to decrypt. + :Type ciphertext: byte string, long or a 2-item tuple as returned by `encrypt` + + :Return: A byte string if ciphertext was a byte string or a tuple + of byte strings. A long otherwise. + """ + wasString=0 + if not isinstance(ciphertext, tuple): + ciphertext=(ciphertext,) + if isinstance(ciphertext[0], bytes): + ciphertext=tuple(map(bytes_to_long, ciphertext)) ; wasString=1 + plaintext=self._decrypt(ciphertext) + if wasString: return long_to_bytes(plaintext) + else: return plaintext + + def sign(self, M, K): + """Sign a piece of data. + + :Parameter M: The piece of data to encrypt. + :Type M: byte string or long + + :Parameter K: A random parameter required by some algorithms + :Type K: byte string or long + + :Return: A tuple with two items. + """ + if (not self.has_private()): + raise TypeError('Private key not available in this object') + if isinstance(M, bytes): M=bytes_to_long(M) + if isinstance(K, bytes): K=bytes_to_long(K) + return self._sign(M, K) + + def verify (self, M, signature): + """Verify the validity of a signature. + + :Parameter M: The expected message. + :Type M: byte string or long + + :Parameter signature: The signature to verify. + :Type signature: tuple with two items, as return by `sign` + + :Return: True if the signature is correct, False otherwise. + """ + if isinstance(M, bytes): M=bytes_to_long(M) + return self._verify(M, signature) + + # alias to compensate for the old validate() name + def validate (self, M, signature): + warnings.warn("validate() method name is obsolete; use verify()", + DeprecationWarning) + + def blind(self, M, B): + """Blind a message to prevent certain side-channel attacks. + + :Parameter M: The message to blind. + :Type M: byte string or long + + :Parameter B: Blinding factor. + :Type B: byte string or long + + :Return: A byte string if M was so. A long otherwise. + """ + wasString=0 + if isinstance(M, bytes): + M=bytes_to_long(M) ; wasString=1 + if isinstance(B, bytes): B=bytes_to_long(B) + blindedmessage=self._blind(M, B) + if wasString: return long_to_bytes(blindedmessage) + else: return blindedmessage + + def unblind(self, M, B): + """Unblind a message after cryptographic processing. + + :Parameter M: The encoded message to unblind. + :Type M: byte string or long + + :Parameter B: Blinding factor. + :Type B: byte string or long + """ + wasString=0 + if isinstance(M, bytes): + M=bytes_to_long(M) ; wasString=1 + if isinstance(B, bytes): B=bytes_to_long(B) + unblindedmessage=self._unblind(M, B) + if wasString: return long_to_bytes(unblindedmessage) + else: return unblindedmessage + + + # The following methods will usually be left alone, except for + # signature-only algorithms. They both return Boolean values + # recording whether this key's algorithm can sign and encrypt. + def can_sign (self): + """Tell if the algorithm can deal with cryptographic signatures. + + This property concerns the *algorithm*, not the key itself. + It may happen that this particular key object hasn't got + the private information required to generate a signature. + + :Return: boolean + """ + return 1 + + def can_encrypt (self): + """Tell if the algorithm can deal with data encryption. + + This property concerns the *algorithm*, not the key itself. + It may happen that this particular key object hasn't got + the private information required to decrypt data. + + :Return: boolean + """ + return 1 + + def can_blind (self): + """Tell if the algorithm can deal with data blinding. + + This property concerns the *algorithm*, not the key itself. + It may happen that this particular key object hasn't got + the private information required carry out blinding. + + :Return: boolean + """ + return 0 + + # The following methods will certainly be overridden by + # subclasses. + + def size (self): + """Tell the maximum number of bits that can be handled by this key. + + :Return: int + """ + return 0 + + def has_private (self): + """Tell if the key object contains private components. + + :Return: bool + """ + return 0 + + def publickey (self): + """Construct a new key carrying only the public information. + + :Return: A new `pubkey` object. + """ + return self + + def __eq__ (self, other): + """__eq__(other): 0, 1 + Compare us to other for equality. + """ + return self.__getstate__() == other.__getstate__() + + def __ne__ (self, other): + """__ne__(other): 0, 1 + Compare us to other for inequality. + """ + return not self.__eq__(other) |