Release 0.1.3: Compatibility with gpg-wks-client

CHANGELOG.md

@@ -1,5 +1,28 @@
 # EasyWKS Changelog
 
+<!-- BEGIN RELEASE v0.1.3 -->
+## Version 0.1.3
+
+Compatibility with gpg-wks-client. 
+
+### Changes
+
+<!-- BEGIN CHANGES 0.1.3 -->
+- Webserver config is now under a `httpd` key, to be more in line with 
+  lmtpd and smtp.
+- Add a `permit_unsigned_response` boolean key that, if set to true,
+  instructs EasyWKS to accept confirmation responses even if they are
+  unsigned, in order to be compatible with version -00 of the draft
+  standard, and thus e.g. gpg-wks-client.
+- Change the detection logic between submission requests and
+  confirmation requests from PGP signature checking to attempting to
+  parse the message as a submission response first.
+- Add a `__main__` module so that easywks can be invoked as a Python
+  module.
+<!-- END CHANGES 0.1.3 -->
+
+<!-- END RELEASE v0.1.3 -->
+
 <!-- BEGIN RELEASE v0.1.2 -->
 ## Version 0.1.2
 

README.md

@@ -75,18 +75,29 @@ Configuration is done in `/etc/easywks.yml` (or any other place as specified by
 
 ```yaml
 ---
-# EasyWKS works inside this directory.  Its PGP keys as well
-# as all the submitted and published keys are stored here. 
+# EasyWKS works inside this directory.  Its PGP keys as well# as all
+# the submitted and published keys are stored here. 
 directory: /var/lib/easywks
-# Number of seconds after which a pending submission request
-# is considered stale and should be removed by easywks clean.
+
+# Number of seconds after which a pending submission request is
+# considered stale and should be removed by easywks clean.
 pending_lifetime: 604800
-# Port configuration for the webserver.  Put this behind a
+
+# Some clients (including recent versions of gpg-wks-client follow an
+# older version of the WKS standard where signing the confirmation
+# response is only recommended, but not required.  Set this option to
+# true if you want to accept such unsigned responses.
+permit_unsigned_response: false
+
+# Port configuration for the webserver.  Put this behind an
 # HTTPS-terminating reverse proxy!
+httpd:
   host: 127.0.0.1
   port: 8080
+
 # Defaults to stdout, supported: stdout, smtp
 mailing_method: smtp
+
 # Configure smtp client options
 smtp:
   # Connect to this SMTP server to send a mail.
@@ -105,13 +116,12 @@ lmtpds:
 # Every domain served by EasyWKS must be listed here
 domains:
   example.org:
-    # Users send their requests to this address.  It's up to
-    # you to make sure that the mails sent their get handed
-    # to EasyWKS.
+    # Users send their requests to this address.  It's up to you to
+    # make sure that the mails sent their get handed to EasyWKS.
     submission_address: webkey@example.org
-    # If you want the PGP key for this domain to be
-    # password-protected, or if you're supplying your own
-    # password-protected key, set the passphrase here:
+    # If you want the PGP key for this domain to be password-
+    # protected, or if you're supplying your own password-protected
+    # key, set the passphrase here:
     passphrase: "Correct Horse Battery Staple"
   # Defaults are gpgwks@<domain> and no password protection.
   example.com: {}

easywks/__init__.py

@@ -1,2 +1,2 @@
 
-__version__ = '0.1.2'
+__version__ = '0.1.3'

easywks/__main__.py

@@ -0,0 +1,4 @@
+
+from .main import main
+
+main()

easywks/config.py

@@ -36,6 +36,15 @@ def _validate_smtp_config(value):
         value['password'] = None
 
 
+def _validate_httpd_config(value):
+    if not isinstance(value, dict):
+        return f'must be a map, got {type(value)}'
+    if not isinstance(value['host'], str):
+        return f'host must be a str, got {type(value["host"])}'
+    if not isinstance(value['port'], int):
+        return f'port must be a int, got {type(value["port"])}'
+
+
 def _validate_lmtpd_config(value):
     if not isinstance(value, dict):
         return f'must be a map, got {type(value)}'
@@ -127,10 +136,13 @@ class _GlobalConfig(_Config):
 
 Config = _GlobalConfig(
     working_directory=_ConfigOption('directory', str, '/var/lib/easywks'),
-    host=_ConfigOption('host', str, '127.0.0.1'),
-    port=_ConfigOption('port', int, 8080),
     pending_lifetime=_ConfigOption('pending_lifetime', int, 604800),
     mailing_method=_ConfigOption('mailing_method', str, 'stdout', validator=_validate_mailing_method),
+    permit_unsigned_response=_ConfigOption('permit_unsigned_response', bool, False),
+    httpd=_ConfigOption('httpd', dict, {
+        'host': 'localhost',
+        'port': 8080
+    }, validator=_validate_httpd_config),
     smtp=_ConfigOption('smtp', dict, {
         'host': 'localhost',
         'port': 25,

easywks/main.py

@@ -37,7 +37,7 @@ def parse_arguments():
 
 def main():
     args = parse_arguments()
-    if args.config is list:
+    if isinstance(args.config, list):
         conf = args.config[0]
     else:
         conf = args.config

easywks/process.py

@@ -52,12 +52,12 @@ def _get_pgp_publickey(parts: List[MIMEPart]) -> PGPKey:
             key, _ = PGPKey.from_blob(part.get_content())
             if key.is_public:
                 if pubkey:
-                    raise EasyWksError('More than one PGP public key in message')
+                    raise EasyWksError('More than one PGP public key in message. Only submit a single key at once.')
                 pubkey = key
         except PGPError:
             pass
     if not pubkey:
-        raise EasyWksError('No PGP public key in message')
+        raise EasyWksError('No PGP public key found in the encrypted message part.')
     return pubkey
 
 
@@ -90,8 +90,6 @@ def _find_confirmation_response(parts: List[MIMEPart]) -> str:
         if 'confirmation-response' in c:
             response = c
             continue
-    if not response:
-        raise EasyWksError('No confirmation response found in message')
     return response
 
 
@@ -105,12 +103,19 @@ def _parse_confirmation_response(pgp: PGPMessage, submission: str, sender: str):
             continue
         key, value = line.split(':', 1)
         rdict[key.strip()] = value.strip()
+    # "from" was renamed to "sender" in draft-koch-openpgp-webkey-service-01.  In addition, gpg-wks-client, which still
+    # implements -00, also violates this standard and uses "address" for the sender and "sender" for the submission
+    # address.
+    if 'from' in rdict:
+        rdict['sender'] = rdict['from']
+    if 'address' in rdict:
+        rdict['sender'] = rdict['address']
     if rdict.get('type', '') != 'confirmation-response':
         raise EasyWksError('Invalid confirmation response: "type" missing or not "confirmation-response"')
     if 'sender' not in rdict or 'nonce' not in rdict:
         raise EasyWksError('Invalid confirmation response: "sender" or "nonce" missing from confirmation response')
     if rdict['sender'] != sender:
-        raise EasyWksError('Confirmation sender does not match message sender')
+        raise EasyWksError(f'Confirmation sender "{rdict["sender"]}" does not match message sender "{sender}"')
     return ConfirmationResponse(rdict['sender'], submission, rdict['nonce'], pgp)
 
 
@@ -138,7 +143,12 @@ def process_mail(mail: bytes):
         leafs = _get_mime_leafs(msg)
         pgp: PGPMessage = _get_pgp_message(leafs)
         decrypted = pgp_decrypt(sender_domain, pgp)
-        if decrypted.is_signed:
+        payload = BytesParser(policy=default).parsebytes(decrypted.message)
+        parts = _get_mime_leafs(payload)
+        # First attempt to find a confirmation response.  It's identifiable much easier due to the
+        # "type: confirmation-response" part in the message.
+        confirmation_response = _find_confirmation_response(parts)
+        if confirmation_response is not None:
             request: ConfirmationResponse = _parse_confirmation_response(decrypted, submission_address, sender_mail)
             try:
                 key = read_pending_key(sender_domain, request.nonce)
@@ -146,7 +156,8 @@ def process_mail(mail: bytes):
                 raise EasyWksError('There is no submission request for this email address, or it has expired. '
                                    'Please resubmit your submission request.')
             # this throws an error if signature verification fails
-            response: PublishResponse = request.verify_signature(key)
+            request.verify_signature(key)
+            response: PublishResponse = request.get_publish_response(key)
             rmsg = response.create_signed_message()
             write_public_key(sender_domain, sender_mail, key)
             remove_pending_key(sender_domain, request.nonce)

easywks/types.py

@@ -10,6 +10,7 @@ from pgpy import PGPKey, PGPMessage, PGPUID
 from pgpy.types import SignatureVerification
 
 from .crypto import pgp_sign
+from .config import Config
 from .util import create_nonce, fingerprint
 
 
@@ -157,15 +158,26 @@ class ConfirmationResponse:
     def nonce(self):
         return self._nonce
 
-    def verify_signature(self, key: PGPKey) -> 'PublishResponse':
+    def get_publish_response(self, key: PGPKey) -> 'PublishResponse':
+        return PublishResponse(self._submitter_addr, self._submission_addr, key)
+
+    def verify_signature(self, key: PGPKey):
+        if not self._msg.is_signed:
+            if not Config.permit_unsigned_response:
+                raise EasyWksError('The confirmation response is not signed. If you used an automated tool such as '
+                                   'gpg-wks-client for submitting your response, please update said tool or try '
+                                   'responding manually.')
+            else:
+                # Unsigned, but permitted
+                return
         uid: PGPUID = key.get_uid(self._submitter_addr)
         if uid is None or uid.email != self._submitter_addr:
             raise EasyWksError(f'UID {self._submitter_addr} not found in PGP key')
         verification: SignatureVerification = key.verify(self._msg)
         for verified, by, sig, subject in verification.good_signatures:
             if fingerprint(key) == fingerprint(by):
-                return PublishResponse(self._submitter_addr, self._submission_addr, key)
-        raise EasyWksError('PGP Signature could not be verified')
+                return
+        raise EasyWksError('PGP signature could not be verified')
 
 
 class PublishResponse:
@@ -214,7 +226,7 @@ Encrypt live everybody is.
         return self._domain
 
     def create_signed_message(self):
-        mpplain = MIMEText(ConfirmationRequest.MAIL_TEXT.format(domain=self.domain, uid=self.submitter_address),
+        mpplain = MIMEText(PublishResponse.MAIL_TEXT.format(domain=self.domain, uid=self.submitter_address),
                            _subtype='plain')
         to_encrypt = PGPMessage.new(mpplain.as_string(policy=default))
         encrypted: PGPMessage = self.key.encrypt(to_encrypt)

package/debian/easywks/etc/easywks.yml

@@ -1,16 +1,27 @@
 ---
-# EasyWKS works inside this directory.  Its PGP keys as well
-# as all the submitted and published keys are stored here.
+# EasyWKS works inside this directory.  Its PGP keys as well as all the
+# submitted and published keys are stored here.
 #directory: /var/lib/easywks
-# Number of seconds after which a pending submission request
-# is considered stale and should be removed by easywks clean.
+
+# Number of seconds after which a pending submission request is
+# considered stale and should be removed by easywks clean.
 #pending_lifetime: 604800
+
+# Some clients (including recent versions of gpg-wks-client follow an
+# older version of the WKS standard where signing the confirmation
+# response is only recommended, but not required.  Set this option to
+# true if you want to accept such unsigned responses.
+#permit_unsigned_response: false
+
 # Port configuration for the webserver.  Put this behind a
 # HTTPS-terminating reverse proxy!
+httpd:
   host: "::1"
   port: 8080
+
 # Defaults to stdout, supported: stdout, smtp
 mailing_method: smtp
+
 # Configure smtp client options
 smtp:
   # Connect to this SMTP server to send a mail.
@@ -22,19 +33,20 @@ smtp:
   # Omit username/password if authentication is not needed.
   #username: webkey
   #password: SuperS3curePassword123
+
 # Configure the LMTP server
 lmtpd:
   host: "::1"
   port: 8024
+
 # Every domain served by EasyWKS must be listed here
 domains:
   # Defaults are gpgwks@<domain> and no password protection.
   example.org:
-    # Users send their requests to this address.  It's up to
-    # you to make sure that the mails sent their get handed
-    # to EasyWKS.
+    # Users send their requests to this address.  It's up to you to
+    # make sure that the mails sent their get handed to EasyWKS.
     submission_address: webkey@example.org
-    # If you want the PGP key for this domain to be
-    # password-protected, or if you're supplying your own
-    # password-protected key, set the passphrase here:
+    # If you want the PGP key for this domain to be password-protected,
+    # or if you're supplying your own password-protected key, set the
+    # passphrase here:
     #passphrase: "Correct Horse Battery Staple"

package/docker/easywks.yml

@@ -7,6 +7,7 @@ smtp:
 lmtpd:
   host: "::"
   port: 24
+httpd:
   host: "::"
   port: 80
 domains: {}