Hash the same content covered by the signature when referencing previous PDUs rather than reusing the PDU content hashes

1 files changed, 40 insertions, 4 deletions

diff --git a/synapse/storage/signatures.py b/synapse/storage/signatures.py
index 1147102489..85eec7ffbe 100644
--- a/synapse/storage/signatures.py
+++ b/synapse/storage/signatures.py
@@ -21,7 +21,7 @@ from twisted.internet import defer
 class SignatureStore(SQLBaseStore):
     """Persistence for PDU signatures and hashes"""
 
-    def _get_pdu_hashes_txn(self, txn, pdu_id, origin):
+    def _get_pdu_content_hashes_txn(self, txn, pdu_id, origin):
         """Get all the hashes for a given PDU.
         Args:
             txn (cursor):
@@ -32,13 +32,14 @@ class SignatureStore(SQLBaseStore):
         """
         query = (
             "SELECT algorithm, hash"
-            " FROM pdu_hashes"
+            " FROM pdu_content_hashes"
             " WHERE pdu_id = ? and origin = ?"
         )
         txn.execute(query, (pdu_id, origin))
         return dict(txn.fetchall())
 
-    def _store_pdu_hash_txn(self, txn, pdu_id, origin, algorithm, hash_bytes):
+    def _store_pdu_content_hash_txn(self, txn, pdu_id, origin, algorithm,
+                                    hash_bytes):
         """Store a hash for a PDU
         Args:
             txn (cursor):
@@ -47,13 +48,48 @@ class SignatureStore(SQLBaseStore):
             algorithm (str): Hashing algorithm.
             hash_bytes (bytes): Hash function output bytes.
         """
-        self._simple_insert_txn(txn, "pdu_hashes", {
+        self._simple_insert_txn(txn, "pdu_content_hashes", {
             "pdu_id": pdu_id,
             "origin": origin,
             "algorithm": algorithm,
             "hash": buffer(hash_bytes),
         })
 
+    def _get_pdu_reference_hashes_txn(self, txn, pdu_id, origin):
+        """Get all the hashes for a given PDU.
+        Args:
+            txn (cursor):
+            pdu_id (str): Id for the PDU.
+            origin (str): origin of the PDU.
+        Returns:
+            A dict of algorithm -> hash.
+        """
+        query = (
+            "SELECT algorithm, hash"
+            " FROM pdu_reference_hashes"
+            " WHERE pdu_id = ? and origin = ?"
+        )
+        txn.execute(query, (pdu_id, origin))
+        return dict(txn.fetchall())
+
+    def _store_pdu_reference_hash_txn(self, txn, pdu_id, origin, algorithm,
+                                      hash_bytes):
+        """Store a hash for a PDU
+        Args:
+            txn (cursor):
+            pdu_id (str): Id for the PDU.
+            origin (str): origin of the PDU.
+            algorithm (str): Hashing algorithm.
+            hash_bytes (bytes): Hash function output bytes.
+        """
+        self._simple_insert_txn(txn, "pdu_reference_hashes", {
+            "pdu_id": pdu_id,
+            "origin": origin,
+            "algorithm": algorithm,
+            "hash": buffer(hash_bytes),
+        })
+
+
     def _get_pdu_origin_signatures_txn(self, txn, pdu_id, origin):
         """Get all the signatures for a given PDU.
         Args: