another attempt

basic_ap.py

@@ -27,7 +27,7 @@ from time import strftime, gmtime
 
 
 from Crypto.Hash import SHA256
-from Crypto.Signature import PKCS1_v1_5
+from Crypto.Signature import pkcs1_15
 from Crypto.PublicKey import RSA
 
 #
@@ -64,44 +64,70 @@ public_key() #generate public_key on first launch
 def build_signing_string(headers, header_values):
     return '\n'.join(map(lambda x: ': '.join([x.lower(), headers[x]]), header_values))
 
-def sign_header(private_key, key_id, host):
+def messageContentDigest(messageBodyJsonStr: str) -> str:
+    msg = messageBodyJsonStr.encode('utf-8')
+    digestStr = SHA256.new(msg).digest()
+    return base64.b64encode(digestStr).decode('utf-8')
+
+
+
+def sign_header(private_key, keyID, host, messageBodyJsonStr):
     """
     Sign HTTP headers 
     """
-    date = strftime("%a, %d %b %Y %H:%M:%S GMT", gmtime()) #RFC1123 Time format
+    date = strftime("%a, %d %b %Y %H:%M:%S %Z", gmtime()) #RFC1123 Time format
 
-    #Based on https://github.com/autogestion/pubgate/
+    #Based on https://code.freedombone.net/bashrc/epicyon/src/main/httpsig.py
     keyfile = open(private_key,'rb').read()
     secret = RSA.import_key(keyfile) 
-    signer = PKCS1_v1_5.new(secret)
-
-
-    headers = { 'request-target': 'post /inbox',
-                'host': host, #this is the destination host 
-                'date': date, 
-                } 
-    sigheaders = headers.keys()
-
-    sigstring = build_signing_string(headers, sigheaders)
-    print(sigstring
-        )
-    digest = SHA256.new()
-    digest.update(sigstring.encode('ascii'))
-    sigdata = base64.b64encode(signer.sign(digest))
-
-    sig = {
-            'keyId': key_id,
-            'algorithm': 'rsa-sha256',
-            'headers': ' '.join(sigheaders),
-            'signature': sigdata.decode('ascii')
+
+    bodyDigest = messageContentDigest(messageBodyJsonStr)
+    contentLength = len(messageBodyJsonStr)
+    print(contentLength)
+    
+    path = '/inbox'
+
+    headers = {
+            '(request-target)': f'post {path}',
+            'host': host,
+            'date': date,
+            'digest': f'SHA-256={bodyDigest}',
+            'content-type': 'application/json',
+            'content-length': str(contentLength)
         }
 
-    headers["signature"] = ','.join(['{}="{}"'.format(k, v) for k, v in sig.items()])
+
+    signedHeaderKeys = headers.keys()
+    signedHeaderText = ''
+
+    for headerKey in signedHeaderKeys:
+        signedHeaderText += f'{headerKey}: {headers[headerKey]}\n'
+
+    signedHeaderText = signedHeaderText.strip()
+    headerDigest = SHA256.new(signedHeaderText.encode('ascii'))
+
+    # Sign the digest
+    rawSignature = pkcs1_15.new(secret).sign(headerDigest)
+    signature = base64.b64encode(rawSignature).decode('ascii')
+
+    # Put it into a valid HTTP signature format
+    signatureDict = {
+        'keyId': keyID,
+        'algorithm': 'rsa-sha256',
+        'headers': ' '.join(signedHeaderKeys),
+        'signature': signature
+    }
+    signatureHeader = ','.join(
+        [f'{k}="{v}"' for k, v in signatureDict.items()])
+    
+
+    headers['signature'] = signatureHeader
 
     return headers
 
 
 
+
 #Flask
 app = flask.Flask(__name__)
 
@@ -138,11 +164,13 @@ def profile(actor):
 @app.route('/post/', methods=['POST','GET'])
 def post():
     date = strftime("%a, %d %b %Y %H:%M:%S GMT", gmtime())
-    activity=json.loads(flask.render_template('create.json',
+
+    json_message=json.loads(flask.render_template('create.json',
         domain=DOMAIN,public_key=public_key(),actor=USERNAME,host='DOMAIN', date=date))
-    signed_headers = sign_header('private.pem', DOMAIN+'/users/'+USERNAME+'#main-key','https://post.lurk.org')
     
-    r = requests.post('https://post.lurk.org/inbox', json=activity, headers=signed_headers)
+    signed_headers = sign_header('private.pem', DOMAIN+'/users/'+USERNAME+'#main-key','https://post.lurk.org', json.dumps(json_message))
+
+    r = requests.post('https://post.lurk.org/inbox', json=json_message, headers=signed_headers)
 
     a = (r.status_code, r.text, r.headers)
     a = str(a)