Move json signature check to its own function

inbox.py

@@ -2780,6 +2780,67 @@ def _inboxQuotaExceeded(queue: {}, queueFilename: str,
     return False
 
 
+def _checkJsonSignature(baseDir: str, queueJson: {}) -> (bool, bool):
+    """check if a json signature exists on this post
+    """
+    hasJsonSignature = False
+    jwebsigType = None
+    originalJson = queueJson['original']
+    if not originalJson.get('@context') or \
+       not originalJson.get('signature'):
+        return hasJsonSignature, jwebsigType
+    if not isinstance(originalJson['signature'], dict):
+        return hasJsonSignature, jwebsigType
+    # see https://tools.ietf.org/html/rfc7515
+    jwebsig = originalJson['signature']
+    # signature exists and is of the expected type
+    if not jwebsig.get('type') or \
+       not jwebsig.get('signatureValue'):
+        return hasJsonSignature, jwebsigType
+    jwebsigType = jwebsig['type']
+    if jwebsigType == 'RsaSignature2017':
+        if hasValidContext(originalJson):
+            hasJsonSignature = True
+        else:
+            unknownContextsFile = \
+                baseDir + '/accounts/unknownContexts.txt'
+            unknownContext = str(originalJson['@context'])
+
+            print('unrecognized @context: ' +
+                  unknownContext)
+
+            alreadyUnknown = False
+            if os.path.isfile(unknownContextsFile):
+                if unknownContext in \
+                   open(unknownContextsFile).read():
+                    alreadyUnknown = True
+
+            if not alreadyUnknown:
+                unknownFile = open(unknownContextsFile, "a+")
+                if unknownFile:
+                    unknownFile.write(unknownContext + '\n')
+                    unknownFile.close()
+    else:
+        print('Unrecognized jsonld signature type: ' +
+              jwebsigType)
+
+        unknownSignaturesFile = \
+            baseDir + '/accounts/unknownJsonSignatures.txt'
+
+        alreadyUnknown = False
+        if os.path.isfile(unknownSignaturesFile):
+            if jwebsigType in \
+               open(unknownSignaturesFile).read():
+                alreadyUnknown = True
+
+        if not alreadyUnknown:
+            unknownFile = open(unknownSignaturesFile, "a+")
+            if unknownFile:
+                unknownFile.write(jwebsigType + '\n')
+                unknownFile.close()
+    return hasJsonSignature, jwebsigType
+
+
 def runInboxQueue(recentPostsCache: {}, maxRecentPosts: int,
                   projectVersion: str,
                   baseDir: str, httpPrefix: str, sendThreads: [], postLog: [],
@@ -2987,57 +3048,7 @@ def runInboxQueue(recentPostsCache: {}, maxRecentPosts: int,
                 print('DEBUG: http header signature check success')
 
         # check if a json signature exists on this post
-        hasJsonSignature = False
+        hasJsonSignature, jwebsigType = _checkJsonSignature(baseDir, queueJson)
-        jwebsigType = None
-        originalJson = queueJson['original']
-        if originalJson.get('@context') and \
-           originalJson.get('signature'):
-            if isinstance(originalJson['signature'], dict):
-                # see https://tools.ietf.org/html/rfc7515
-                jwebsig = originalJson['signature']
-                # signature exists and is of the expected type
-                if jwebsig.get('type') and jwebsig.get('signatureValue'):
-                    jwebsigType = jwebsig['type']
-                    if jwebsigType == 'RsaSignature2017':
-                        if hasValidContext(originalJson):
-                            hasJsonSignature = True
-                        else:
-                            unknownContextsFile = \
-                                baseDir + '/accounts/unknownContexts.txt'
-                            unknownContext = str(originalJson['@context'])
-
-                            print('unrecognized @context: ' +
-                                  unknownContext)
-
-                            alreadyUnknown = False
-                            if os.path.isfile(unknownContextsFile):
-                                if unknownContext in \
-                                   open(unknownContextsFile).read():
-                                    alreadyUnknown = True
-
-                            if not alreadyUnknown:
-                                unknownFile = open(unknownContextsFile, "a+")
-                                if unknownFile:
-                                    unknownFile.write(unknownContext + '\n')
-                                    unknownFile.close()
-                    else:
-                        print('Unrecognized jsonld signature type: ' +
-                              jwebsigType)
-
-                        unknownSignaturesFile = \
-                            baseDir + '/accounts/unknownJsonSignatures.txt'
-
-                        alreadyUnknown = False
-                        if os.path.isfile(unknownSignaturesFile):
-                            if jwebsigType in \
-                               open(unknownSignaturesFile).read():
-                                alreadyUnknown = True
-
-                        if not alreadyUnknown:
-                            unknownFile = open(unknownSignaturesFile, "a+")
-                            if unknownFile:
-                                unknownFile.write(jwebsigType + '\n')
-                                unknownFile.close()
 
         # strict enforcement of json signatures
         if not hasJsonSignature:
@@ -3053,6 +3064,7 @@ def runInboxQueue(recentPostsCache: {}, maxRecentPosts: int,
                     pprint(queueJson['httpHeaders'])
 
             if verifyAllSignatures:
+                originalJson = queueJson['original']
                 print('Queue: inbox post does not have a jsonld signature ' +
                       keyId + ' ' + str(originalJson))
 
@@ -3066,6 +3078,7 @@ def runInboxQueue(recentPostsCache: {}, maxRecentPosts: int,
             if httpSignatureFailed or verifyAllSignatures:
                 # use the original json message received, not one which
                 # may have been modified along the way
+                originalJson = queueJson['original']
                 if not verifyJsonSignature(originalJson, pubKey):
                     if debug:
                         print('WARN: jsonld inbox signature check failed ' +