diff options
| -rw-r--r-- | alot/crypto.py | 31 | ||||
| -rw-r--r-- | alot/db/message.py | 8 | ||||
| -rw-r--r-- | alot/db/utils.py | 31 | ||||
| -rwxr-xr-x | setup.py | 2 | ||||
| -rw-r--r-- | tests/db/message_test.py | 3 |
5 files changed, 60 insertions, 15 deletions
diff --git a/alot/crypto.py b/alot/crypto.py index a05db2fc..38b8727a 100644 --- a/alot/crypto.py +++ b/alot/crypto.py @@ -206,15 +206,22 @@ def verify_detached(message, signature): raise GPGProblem(str(e), code=e.getcode()) -def decrypt_verify(encrypted): +def decrypt_verify(encrypted, session_keys=None): """Decrypts the given ciphertext string and returns both the signatures (if any) and the plaintext. :param bytes encrypted: the mail to decrypt + :param list[str] session_keys: a list OpenPGP session keys :returns: the signatures and decrypted plaintext data :rtype: tuple[list[gpg.resuit.Signature], str] :raises: :class:`~alot.errors.GPGProblem` if the decryption fails """ + if session_keys is not None: + try: + return _decrypt_verify_session_keys(encrypted, session_keys) + except GPGProblem: + pass + ctx = gpg.core.Context() try: plaintext, _, verify_result = ctx.decrypt(encrypted, verify=True) @@ -228,6 +235,28 @@ def decrypt_verify(encrypted): return sigs, plaintext +def _decrypt_verify_session_keys(encrypted, session_keys): + """Decrypts the given ciphertext string using the session_keys + and returns both the signatures (if any) and the plaintext. + + :param bytes encrypted: the mail to decrypt + :param list[str] session_keys: a list OpenPGP session keys + :returns: the signatures and decrypted plaintext data + :rtype: tuple[list[gpg.resuit.Signature], str] + :raises: :class:`~alot.errors.GPGProblem` if the decryption fails + """ + for key in session_keys: + ctx = gpg.core.Context() + ctx.set_ctx_flag("override-session-key", key) + try: + (plaintext, _, verify_result) = ctx.decrypt( + encrypted, verify=True) + except gpg.errors.GPGMEError as e: + continue + return verify_result.signatures, plaintext + raise GPGProblem("No valid session key", code=GPGCode.NOT_FOUND) + + def validate_key(key, sign=False, encrypt=False): """Assert that a key is valide and optionally that it can be used for signing or encrypting. Raise GPGProblem otherwise. diff --git a/alot/db/message.py b/alot/db/message.py index 3c860cac..ae06acc6 100644 --- a/alot/db/message.py +++ b/alot/db/message.py @@ -54,6 +54,11 @@ class Message(object): self._attachments = None # will be read upon first use self._tags = set(msg.get_tags()) + self._session_keys = [] + for name, value in msg.get_properties("session-key", exact=True): + if name == "session-key": + self._session_keys.append(value) + try: sender = decode_header(msg.get_header('From')) if not sender: @@ -102,7 +107,8 @@ class Message(object): if not self._email: try: with open(path, 'rb') as f: - self._email = utils.decrypted_message_from_bytes(f.read()) + self._email = utils.decrypted_message_from_bytes( + f.read(), self._session_keys) except IOError: self._email = email.message_from_string( warning, policy=email.policy.SMTP) diff --git a/alot/db/utils.py b/alot/db/utils.py index c883bb42..abbdd4ea 100644 --- a/alot/db/utils.py +++ b/alot/db/utils.py @@ -140,7 +140,7 @@ def _handle_signatures(original, message, params): add_signature_headers(original, sigs, malformed) -def _handle_encrypted(original, message): +def _handle_encrypted(original, message, session_keys=None): """Handle encrypted messages helper. RFC 3156 is quite strict: @@ -155,6 +155,8 @@ def _handle_encrypted(original, message): :type original: :class:`email.message.Message` :param message: The multipart/signed payload to verify :type message: :class:`email.message.Message` + :param session_keys: a list OpenPGP session keys + :type session_keys: [str] """ malformed = False @@ -172,14 +174,14 @@ def _handle_encrypted(original, message): # This should be safe because PGP uses US-ASCII characters only payload = message.get_payload(1).get_payload().encode('ascii') try: - sigs, d = crypto.decrypt_verify(payload) + sigs, d = crypto.decrypt_verify(payload, session_keys) except GPGProblem as e: # signature verification failures end up here too if the combined # method is used, currently this prevents the interpretation of the # recovered plain text mail. maybe that's a feature. malformed = str(e) else: - n = decrypted_message_from_bytes(d) + n = decrypted_message_from_bytes(d, session_keys) # add the decrypted message to message. note that n contains all # the attachments, no need to walk over n here. @@ -214,7 +216,7 @@ def _handle_encrypted(original, message): original.attach(content) -def decrypted_message_from_file(handle): +def decrypted_message_from_file(handle, session_keys=None): '''Reads a mail from the given file-like object and returns an email object, very much like email.message_from_file. In addition to that OpenPGP encrypted data is detected and decrypted. If this @@ -222,18 +224,21 @@ def decrypted_message_from_file(handle): message are added to the returned message object. :param handle: a file-like object + :param session_keys: a list OpenPGP session keys :returns: :class:`email.message.Message` possibly augmented with decrypted data ''' - return decrypted_message_from_message(email.message_from_file(handle)) + return decrypted_message_from_message(email.message_from_file(handle), + session_keys) -def decrypted_message_from_message(m): +def decrypted_message_from_message(m, session_keys=None): '''Detect and decrypt OpenPGP encrypted data in an email object. If this succeeds, any mime messages found in the recovered plaintext message are added to the returned message object. :param m: an email object + :param session_keys: a list OpenPGP session keys :returns: :class:`email.message.Message` possibly augmented with decrypted data ''' @@ -253,7 +258,7 @@ def decrypted_message_from_message(m): elif (m.get_content_subtype() == 'encrypted' and p.get('protocol') == _APP_PGP_ENC and 'Version: 1' in m.get_payload(0).get_payload()): - _handle_encrypted(m, m) + _handle_encrypted(m, m, session_keys) # It is also possible to put either of the abov into a multipart/mixed # segment @@ -268,12 +273,12 @@ def decrypted_message_from_message(m): _handle_signatures(m, sub, p) elif (sub.get_content_subtype() == 'encrypted' and p.get('protocol') == _APP_PGP_ENC): - _handle_encrypted(m, sub) + _handle_encrypted(m, sub, session_keys) return m -def decrypted_message_from_string(s): +def decrypted_message_from_string(s, session_keys=None): '''Reads a mail from the given string. This is the equivalent of :func:`email.message_from_string` which does nothing but to wrap the given string in a StringIO object and to call @@ -283,16 +288,18 @@ def decrypted_message_from_string(s): details. ''' - return decrypted_message_from_file(io.StringIO(s)) + return decrypted_message_from_file(io.StringIO(s), session_keys) -def decrypted_message_from_bytes(bytestring): +def decrypted_message_from_bytes(bytestring, session_keys=None): """Create a Message from bytes. :param bytes bytestring: an email message as raw bytes + :param session_keys: a list OpenPGP session keys """ return decrypted_message_from_message( - email.message_from_bytes(bytestring, policy=email.policy.SMTP)) + email.message_from_bytes(bytestring, policy=email.policy.SMTP), + session_keys) def extract_headers(mail, headers=None): @@ -45,7 +45,7 @@ setup( ['alot = alot.__main__:main'], }, install_requires=[ - 'notmuch>=0.26', + 'notmuch>=0.27', 'urwid>=1.3.0', 'urwidtrees>=1.0', 'twisted>=10.2.0', diff --git a/tests/db/message_test.py b/tests/db/message_test.py index caa70a44..29ed5ee6 100644 --- a/tests/db/message_test.py +++ b/tests/db/message_test.py @@ -57,6 +57,9 @@ class MockNotmuchMessage(object): def get_tags(self): return self.mock_tags + def get_properties(self, prop, exact=False): + return [] + class TestMessage(unittest.TestCase): |