def testObjEncode5(self):
# Encode type with explicit tag
der = DerObject(0x10, explicit=5)
der.payload = b("xxll")
self.assertEqual(der.encode(), b("\xa5\x06\x10\x04xxll"))
def testObjEncode2(self):
# Initialize with payload
der = DerObject(0x03, b('\x12\x12'))
self.assertEquals(der.encode(), b('\x03\x02\x12\x12'))
def testObjEncode3(self):
# Long payload
der = DerObject(b('\x10'))
der.payload = b("0") * 128
self.assertEquals(der.encode(), b('\x10\x81\x80' + "0" * 128))
def testObjDecode6(self):
# Arbitrary DER object
der = DerObject()
der.decode(b('\x65\x01\x88'))
self.assertEquals(der._tag_octet, 0x65)
self.assertEquals(der.payload, b('\x88'))
def testObjDecode8(self):
# Verify that decode returns the object
der = DerObject(0x02)
self.assertEqual(der, der.decode(b('\x02\x02\x01\x02')))
def testObjDecode2(self):
# Decode long payload
der = DerObject(0x02)
der.decode(b('\x02\x81\x80' + "1" * 128))
self.assertEquals(der.payload, b("1") * 128)
self.assertEquals(der._tag_octet, 0x02)
def testObjDecode5(self):
# Decode payload with unexpected tag gives error
der = DerObject(0x02)
self.assertRaises(ValueError, der.decode, b('\x03\x02\x01\x02'))
def testObjDecode1(self):
# Decode short payload
der = DerObject(0x02)
der.decode(b('\x02\x02\x01\x02'))
self.assertEqual(der.payload, b("\x01\x02"))
self.assertEqual(der._idOctet, 0x02)
def testObjDecode2(self):
# Decode short payload
der = DerObject()
der.decode(b('\x22\x81\x80' + "1"*128))
self.assertEquals(der.payload, b("1")*128)
self.assertEquals(der.typeTag, 0x22)
def testObjDecode1(self):
# Decode short payload
der = DerObject()
der.decode(b('\x20\x02\x01\x02'))
self.assertEquals(der.payload, b("\x01\x02"))
self.assertEquals(der.typeTag, 0x20)
def testObjEncode2(self):
# Known types
der = DerObject('SEQUENCE')
self.assertEquals(der.encode(), b('\x30\x00'))
der = DerObject('BIT STRING')
self.assertEquals(der.encode(), b('\x03\x00'))
def exportKey(self, format='PEM', passphrase=None, pkcs=1):
"""Export this RSA key.
:Parameter format: The format to use for wrapping the key.
- *'DER'*. Binary encoding, always unencrypted.
- *'PEM'*. Textual encoding, done according to `RFC1421`_/`RFC1423`_.
Unencrypted (default) or encrypted.
- *'OpenSSH'*. Textual encoding, done according to OpenSSH specification.
Only suitable for public keys (not private keys).
:Type format: string
:Parameter passphrase: In case of PEM, the pass phrase to derive the encryption key from.
:Type passphrase: string
:Parameter pkcs: The PKCS standard to follow for assembling the key.
You have two choices:
- with **1**, the public key is embedded into an X.509 `SubjectPublicKeyInfo` DER SEQUENCE.
The private key is embedded into a `PKCS#1`_ `RSAPrivateKey` DER SEQUENCE.
This mode is the default.
- with **8**, the private key is embedded into a `PKCS#8`_ `PrivateKeyInfo` DER SEQUENCE.
This mode is not available for public keys.
PKCS standards are not relevant for the *OpenSSH* format.
:Type pkcs: integer
:Return: A byte string with the encoded public or private half.
:Raise ValueError:
When the format is unknown.
.. _RFC1421: http://www.ietf.org/rfc/rfc1421.txt
.. _RFC1423: http://www.ietf.org/rfc/rfc1423.txt
.. _`PKCS#1`: http://www.ietf.org/rfc/rfc3447.txt
.. _`PKCS#8`: http://www.ietf.org/rfc/rfc5208.txt
"""
if passphrase is not None:
passphrase = tobytes(passphrase)
if format=='OpenSSH':
eb = long_to_bytes(self.e)
nb = long_to_bytes(self.n)
if bord(eb[0]) & 0x80: eb=bchr(0x00)+eb
if bord(nb[0]) & 0x80: nb=bchr(0x00)+nb
keyparts = [ 'ssh-rsa', eb, nb ]
keystring = ''.join([ struct.pack(">I",len(kp))+kp for kp in keyparts])
return 'ssh-rsa '+binascii.b2a_base64(keystring)[:-1]
# DER format is always used, even in case of PEM, which simply
# encodes it into BASE64.
der = DerSequence()
if self.has_private():
keyType= { 1: 'RSA PRIVATE', 8: 'PRIVATE' }[pkcs]
der[:] = [ 0, self.n, self.e, self.d, self.p, self.q,
self.d % (self.p-1), self.d % (self.q-1),
inverse(self.q, self.p) ]
if pkcs==8:
derkey = der.encode()
der = DerSequence([0])
der.append(algorithmIdentifier)
der.append(DerObject('OCTET STRING', derkey).encode())
else:
keyType = "PUBLIC"
der.append(algorithmIdentifier)
bitmap = DerObject('BIT STRING')
derPK = DerSequence( [ self.n, self.e ] )
bitmap.payload = bchr(0x00) + derPK.encode()
der.append(bitmap.encode())
if format=='DER':
return der.encode()
if format=='PEM':
pem = b("-----BEGIN " + keyType + " KEY-----\n")
objenc = None
if passphrase and keyType.endswith('PRIVATE'):
# We only support 3DES for encryption
import Crypto.Hash.MD5
from Crypto.Cipher import DES3
from Crypto.Protocol.KDF import PBKDF1
salt = self._randfunc(8)
key = PBKDF1(passphrase, salt, 16, 1, Crypto.Hash.MD5)
key += PBKDF1(key+passphrase, salt, 8, 1, Crypto.Hash.MD5)
objenc = DES3.new(key, Crypto.Cipher.DES3.MODE_CBC, salt)
pem += b('Proc-Type: 4,ENCRYPTED\n')
pem += b('DEK-Info: DES-EDE3-CBC,') + binascii.b2a_hex(salt).upper() + b('\n\n')
binaryKey = der.encode()
if objenc:
# Add PKCS#7-like padding
padding = objenc.block_size-len(binaryKey)%objenc.block_size
binaryKey = objenc.encrypt(binaryKey+bchr(padding)*padding)
# Each BASE64 line can take up to 64 characters (=48 bytes of data)
chunks = [ binascii.b2a_base64(binaryKey[i:i+48]) for i in range(0, len(binaryKey), 48) ]
pem += b('').join(chunks)
pem += b("-----END " + keyType + " KEY-----")
return pem
return ValueError("Unknown key format '%s'. Cannot export the RSA key." % format)