diff options
Diffstat (limited to 'src/lib/tlslite/utils/OpenSSL_TripleDES.py')
-rwxr-xr-x | src/lib/tlslite/utils/OpenSSL_TripleDES.py | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/src/lib/tlslite/utils/OpenSSL_TripleDES.py b/src/lib/tlslite/utils/OpenSSL_TripleDES.py new file mode 100755 index 000000000..f5ba16565 --- /dev/null +++ b/src/lib/tlslite/utils/OpenSSL_TripleDES.py @@ -0,0 +1,44 @@ +"""OpenSSL/M2Crypto 3DES implementation.""" + +from cryptomath import * +from TripleDES import * + +if m2cryptoLoaded: + + def new(key, mode, IV): + return OpenSSL_TripleDES(key, mode, IV) + + class OpenSSL_TripleDES(TripleDES): + + def __init__(self, key, mode, IV): + TripleDES.__init__(self, key, mode, IV, "openssl") + self.key = key + self.IV = IV + + def _createContext(self, encrypt): + context = m2.cipher_ctx_new() + cipherType = m2.des_ede3_cbc() + m2.cipher_init(context, cipherType, self.key, self.IV, encrypt) + return context + + def encrypt(self, plaintext): + TripleDES.encrypt(self, plaintext) + context = self._createContext(1) + ciphertext = m2.cipher_update(context, plaintext) + m2.cipher_ctx_free(context) + self.IV = ciphertext[-self.block_size:] + return ciphertext + + def decrypt(self, ciphertext): + TripleDES.decrypt(self, ciphertext) + context = self._createContext(0) + #I think M2Crypto has a bug - it fails to decrypt and return the last block passed in. + #To work around this, we append sixteen zeros to the string, below: + plaintext = m2.cipher_update(context, ciphertext+('\0'*16)) + + #If this bug is ever fixed, then plaintext will end up having a garbage + #plaintext block on the end. That's okay - the below code will ignore it. + plaintext = plaintext[:len(ciphertext)] + m2.cipher_ctx_free(context) + self.IV = ciphertext[-self.block_size:] + return plaintext
\ No newline at end of file |