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Diffstat (limited to 'src/lib/tlslite/utils/RSAKey.py')
| -rwxr-xr-x | src/lib/tlslite/utils/RSAKey.py | 264 |
1 files changed, 264 insertions, 0 deletions
diff --git a/src/lib/tlslite/utils/RSAKey.py b/src/lib/tlslite/utils/RSAKey.py new file mode 100755 index 000000000..37c292df5 --- /dev/null +++ b/src/lib/tlslite/utils/RSAKey.py @@ -0,0 +1,264 @@ +"""Abstract class for RSA.""" + +from cryptomath import * + + +class RSAKey: + """This is an abstract base class for RSA keys. + + Particular implementations of RSA keys, such as + L{OpenSSL_RSAKey.OpenSSL_RSAKey}, + L{Python_RSAKey.Python_RSAKey}, and + L{PyCrypto_RSAKey.PyCrypto_RSAKey}, + inherit from this. + + To create or parse an RSA key, don't use one of these classes + directly. Instead, use the factory functions in + L{tlslite.utils.keyfactory}. + """ + + def __init__(self, n=0, e=0): + """Create a new RSA key. + + If n and e are passed in, the new key will be initialized. + + @type n: int + @param n: RSA modulus. + + @type e: int + @param e: RSA public exponent. + """ + raise NotImplementedError() + + def __len__(self): + """Return the length of this key in bits. + + @rtype: int + """ + return numBits(self.n) + + def hasPrivateKey(self): + """Return whether or not this key has a private component. + + @rtype: bool + """ + raise NotImplementedError() + + def hash(self): + """Return the cryptoID <keyHash> value corresponding to this + key. + + @rtype: str + """ + raise NotImplementedError() + + def getSigningAlgorithm(self): + """Return the cryptoID sigAlgo value corresponding to this key. + + @rtype: str + """ + return "pkcs1-sha1" + + def hashAndSign(self, bytes): + """Hash and sign the passed-in bytes. + + This requires the key to have a private component. It performs + a PKCS1-SHA1 signature on the passed-in data. + + @type bytes: str or L{array.array} of unsigned bytes + @param bytes: The value which will be hashed and signed. + + @rtype: L{array.array} of unsigned bytes. + @return: A PKCS1-SHA1 signature on the passed-in data. + """ + if not isinstance(bytes, type("")): + bytes = bytesToString(bytes) + hashBytes = stringToBytes(sha.sha(bytes).digest()) + prefixedHashBytes = self._addPKCS1SHA1Prefix(hashBytes) + sigBytes = self.sign(prefixedHashBytes) + return sigBytes + + def hashAndVerify(self, sigBytes, bytes): + """Hash and verify the passed-in bytes with the signature. + + This verifies a PKCS1-SHA1 signature on the passed-in data. + + @type sigBytes: L{array.array} of unsigned bytes + @param sigBytes: A PKCS1-SHA1 signature. + + @type bytes: str or L{array.array} of unsigned bytes + @param bytes: The value which will be hashed and verified. + + @rtype: bool + @return: Whether the signature matches the passed-in data. + """ + if not isinstance(bytes, type("")): + bytes = bytesToString(bytes) + hashBytes = stringToBytes(sha.sha(bytes).digest()) + prefixedHashBytes = self._addPKCS1SHA1Prefix(hashBytes) + return self.verify(sigBytes, prefixedHashBytes) + + def sign(self, bytes): + """Sign the passed-in bytes. + + This requires the key to have a private component. It performs + a PKCS1 signature on the passed-in data. + + @type bytes: L{array.array} of unsigned bytes + @param bytes: The value which will be signed. + + @rtype: L{array.array} of unsigned bytes. + @return: A PKCS1 signature on the passed-in data. + """ + if not self.hasPrivateKey(): + raise AssertionError() + paddedBytes = self._addPKCS1Padding(bytes, 1) + m = bytesToNumber(paddedBytes) + if m >= self.n: + raise ValueError() + c = self._rawPrivateKeyOp(m) + sigBytes = numberToBytes(c) + return sigBytes + + def verify(self, sigBytes, bytes): + """Verify the passed-in bytes with the signature. + + This verifies a PKCS1 signature on the passed-in data. + + @type sigBytes: L{array.array} of unsigned bytes + @param sigBytes: A PKCS1 signature. + + @type bytes: L{array.array} of unsigned bytes + @param bytes: The value which will be verified. + + @rtype: bool + @return: Whether the signature matches the passed-in data. + """ + paddedBytes = self._addPKCS1Padding(bytes, 1) + c = bytesToNumber(sigBytes) + if c >= self.n: + return False + m = self._rawPublicKeyOp(c) + checkBytes = numberToBytes(m) + return checkBytes == paddedBytes + + def encrypt(self, bytes): + """Encrypt the passed-in bytes. + + This performs PKCS1 encryption of the passed-in data. + + @type bytes: L{array.array} of unsigned bytes + @param bytes: The value which will be encrypted. + + @rtype: L{array.array} of unsigned bytes. + @return: A PKCS1 encryption of the passed-in data. + """ + paddedBytes = self._addPKCS1Padding(bytes, 2) + m = bytesToNumber(paddedBytes) + if m >= self.n: + raise ValueError() + c = self._rawPublicKeyOp(m) + encBytes = numberToBytes(c) + return encBytes + + def decrypt(self, encBytes): + """Decrypt the passed-in bytes. + + This requires the key to have a private component. It performs + PKCS1 decryption of the passed-in data. + + @type encBytes: L{array.array} of unsigned bytes + @param encBytes: The value which will be decrypted. + + @rtype: L{array.array} of unsigned bytes or None. + @return: A PKCS1 decryption of the passed-in data or None if + the data is not properly formatted. + """ + if not self.hasPrivateKey(): + raise AssertionError() + c = bytesToNumber(encBytes) + if c >= self.n: + return None + m = self._rawPrivateKeyOp(c) + decBytes = numberToBytes(m) + if (len(decBytes) != numBytes(self.n)-1): #Check first byte + return None + if decBytes[0] != 2: #Check second byte + return None + for x in range(len(decBytes)-1): #Scan through for zero separator + if decBytes[x]== 0: + break + else: + return None + return decBytes[x+1:] #Return everything after the separator + + def _rawPrivateKeyOp(self, m): + raise NotImplementedError() + + def _rawPublicKeyOp(self, c): + raise NotImplementedError() + + def acceptsPassword(self): + """Return True if the write() method accepts a password for use + in encrypting the private key. + + @rtype: bool + """ + raise NotImplementedError() + + def write(self, password=None): + """Return a string containing the key. + + @rtype: str + @return: A string describing the key, in whichever format (PEM + or XML) is native to the implementation. + """ + raise NotImplementedError() + + def writeXMLPublicKey(self, indent=''): + """Return a string containing the key. + + @rtype: str + @return: A string describing the public key, in XML format. + """ + return Python_RSAKey(self.n, self.e).write(indent) + + def generate(bits): + """Generate a new key with the specified bit length. + + @rtype: L{tlslite.utils.RSAKey.RSAKey} + """ + raise NotImplementedError() + generate = staticmethod(generate) + + + # ************************************************************************** + # Helper Functions for RSA Keys + # ************************************************************************** + + def _addPKCS1SHA1Prefix(self, bytes): + prefixBytes = createByteArraySequence(\ + [48,33,48,9,6,5,43,14,3,2,26,5,0,4,20]) + prefixedBytes = prefixBytes + bytes + return prefixedBytes + + def _addPKCS1Padding(self, bytes, blockType): + padLength = (numBytes(self.n) - (len(bytes)+3)) + if blockType == 1: #Signature padding + pad = [0xFF] * padLength + elif blockType == 2: #Encryption padding + pad = createByteArraySequence([]) + while len(pad) < padLength: + padBytes = getRandomBytes(padLength * 2) + pad = [b for b in padBytes if b != 0] + pad = pad[:padLength] + else: + raise AssertionError() + + #NOTE: To be proper, we should add [0,blockType]. However, + #the zero is lost when the returned padding is converted + #to a number, so we don't even bother with it. Also, + #adding it would cause a misalignment in verify() + padding = createByteArraySequence([blockType] + pad + [0]) + paddedBytes = padding + bytes + return paddedBytes |