From b7bf30ca644775b38473571e47cbe102a5216d19 Mon Sep 17 00:00:00 2001 From: Victor Shyba Date: Sun, 27 Nov 2016 01:13:04 -0300 Subject: [refactor] adds PipeableWriter to pipe two streams VerifiedEncryptor and VerifiedDecryptor are just a pipe and a fan-out. This class provides both behaviors to two distinct writeable things. --- client/src/leap/soledad/client/_crypto.py | 45 +++++++++++-------------------- 1 file changed, 15 insertions(+), 30 deletions(-) (limited to 'client/src/leap/soledad') diff --git a/client/src/leap/soledad/client/_crypto.py b/client/src/leap/soledad/client/_crypto.py index 22335f9d..aaae7b92 100644 --- a/client/src/leap/soledad/client/_crypto.py +++ b/client/src/leap/soledad/client/_crypto.py @@ -201,7 +201,7 @@ class BlobEncryptor(object): self._hmac_writer = HMACWriter(mac_key) self._write_preamble() - self._crypter = VerifiedEncrypter(_aes, self._hmac_writer) + self._crypter = PipeableWriter(_aes, self._hmac_writer) @property def iv(self): @@ -276,7 +276,7 @@ class BlobDecryptor(object): sym_key = _get_sym_key_for_doc(doc_info.doc_id, secret) _aes = AESConsumer(sym_key, iv, self.result, operation=AESConsumer.decrypt) - self._decrypter = VerifiedDecrypter(_aes, _hmac_writer) + self._decrypter = PipeableWriter(_aes, _hmac_writer, pipe=False) self._producer = FileBodyProducer(ciphertext_fd, readSize=2**16) @@ -354,48 +354,33 @@ class HMACWriter(object): return self.result.getvalue() -class VerifiedEncrypter(object): +class PipeableWriter(object): """ - A Twisted's Consumer implementation combining AESEncryptor and HMACWriter. - It directs the resulting ciphertext into HMAC-SHA512 processing. + A Twisted's Consumer implementation that flows data into two writers. + Here we can combine AESEncryptor and HMACWriter. + It directs the resulting ciphertext into HMAC-SHA512 processing if + pipe=True or writes the ciphertext to both (fan out, which is the case when + decrypting). """ implements(interfaces.IConsumer) - def __init__(self, crypter, hmac_writer): - self.crypter = crypter + def __init__(self, aes_writer, hmac_writer, pipe=True): + self.pipe = pipe + self.aes_writer = aes_writer self.hmac_writer = hmac_writer def write(self, data): - enc_chunk = self.crypter.write(data) + enc_chunk = self.aes_writer.write(data) + if not self.pipe: + enc_chunk = data self.hmac_writer.write(enc_chunk) def end(self): - ciphertext = self.crypter.end() + ciphertext = self.aes_writer.end() content_hmac = self.hmac_writer.end() return ciphertext, content_hmac -class VerifiedDecrypter(object): - """ - A Twisted's Consumer implementation combining AESDecryptor and HMACWriter. - It directs the resulting ciphertext into HMAC-SHA512 processing, then - decrypt. - """ - implements(interfaces.IConsumer) - - def __init__(self, decrypter, hmac_writer): - self.decrypter = decrypter - self.hmac_writer = hmac_writer - - def write(self, enc_chunk): - self.hmac_writer.write(enc_chunk) - self.decrypter.write(enc_chunk) - - def end(self): - self.decrypter.end() - self.hmac_writer.end() - - class AESConsumer(object): """ A Twisted's Consumer implementation that takes an input file descriptor and -- cgit v1.2.3