Add existing GAM 3.21 code

gdata/Crypto/PublicKey/pubkey.py

@@ -0,0 +1,172 @@
+#
+#   pubkey.py : Internal functions for public key operations
+#
+#  Part of the Python Cryptography Toolkit
+#
+# Distribute and use freely; there are no restrictions on further
+# dissemination and usage except those imposed by the laws of your
+# country of residence.  This software is provided "as is" without
+# warranty of fitness for use or suitability for any purpose, express
+# or implied. Use at your own risk or not at all.
+#
+
+__revision__ = "$Id: pubkey.py,v 1.11 2003/04/03 20:36:14 akuchling Exp $"
+
+import types, warnings
+from Crypto.Util.number import *
+
+# Basic public key class
+class pubkey:
+    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 d.has_key(key): d[key]=long(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 d.has_key(key): self.__dict__[key]=bignum(d[key])
+
+    def encrypt(self, plaintext, K):
+        """encrypt(plaintext:string|long, K:string|long) : tuple
+        Encrypt the string or integer plaintext.  K is a random
+        parameter required by some algorithms.
+        """
+        wasString=0
+        if isinstance(plaintext, types.StringType):
+            plaintext=bytes_to_long(plaintext) ; wasString=1
+        if isinstance(K, types.StringType):
+            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(ciphertext:tuple|string|long): string
+        Decrypt 'ciphertext' using this key.
+        """
+        wasString=0
+        if not isinstance(ciphertext, types.TupleType):
+            ciphertext=(ciphertext,)
+        if isinstance(ciphertext[0], types.StringType):
+            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(M : string|long, K:string|long) : tuple
+        Return a tuple containing the signature for the message M.
+        K is a random parameter required by some algorithms.
+        """
+        if (not self.has_private()):
+            raise error, 'Private key not available in this object'
+        if isinstance(M, types.StringType): M=bytes_to_long(M)
+        if isinstance(K, types.StringType): K=bytes_to_long(K)
+        return self._sign(M, K)
+
+    def verify (self, M, signature):
+        """verify(M:string|long, signature:tuple) : bool
+        Verify that the signature is valid for the message M;
+        returns true if the signature checks out.
+        """
+        if isinstance(M, types.StringType): 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(M : string|long, B : string|long) : string|long
+        Blind message M using blinding factor B.
+        """
+        wasString=0
+        if isinstance(M, types.StringType):
+            M=bytes_to_long(M) ; wasString=1
+        if isinstance(B, types.StringType): 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(M : string|long, B : string|long) : string|long
+        Unblind message M using blinding factor B.
+        """
+        wasString=0
+        if isinstance(M, types.StringType):
+            M=bytes_to_long(M) ; wasString=1
+        if isinstance(B, types.StringType): 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):
+        """can_sign() : bool
+        Return a Boolean value recording whether this algorithm can
+        generate signatures.  (This does not imply that this
+        particular key object has the private information required to
+        to generate a signature.)
+        """
+        return 1
+
+    def can_encrypt (self):
+        """can_encrypt() : bool
+        Return a Boolean value recording whether this algorithm can
+        encrypt data.  (This does not imply that this
+        particular key object has the private information required to
+        to decrypt a message.)
+        """
+        return 1
+
+    def can_blind (self):
+        """can_blind() : bool
+        Return a Boolean value recording whether this algorithm can
+        blind data.  (This does not imply that this
+        particular key object has the private information required to
+        to blind a message.)
+        """
+        return 0
+
+    # The following methods will certainly be overridden by
+    # subclasses.
+
+    def size (self):
+        """size() : int
+        Return the maximum number of bits that can be handled by this key.
+        """
+        return 0
+
+    def has_private (self):
+        """has_private() : bool
+        Return a Boolean denoting whether the object contains
+        private components.
+        """
+        return 0
+
+    def publickey (self):
+        """publickey(): object
+        Return a new key object containing only the public information.
+        """
+        return self
+
+    def __eq__ (self, other):
+        """__eq__(other): 0, 1
+        Compare us to other for equality.
+        """
+        return self.__getstate__() == other.__getstate__()