[Mint] Fix key rotation (#177)

* rotate keys every 5 seconds

* every 10 seconds

* do not regenerate all past keys for each epoch cycle

* remove automatic rotation

* make format

* print to logger

* rephrase print

cashu/lightning/fake.py

@@ -14,6 +14,8 @@ from .base import (
     Wallet,
 )
 
+BRR = True
+
 
 class FakeWallet(Wallet):
     """https://github.com/lnbits/lnbits"""
@@ -77,7 +79,7 @@ class FakeWallet(Wallet):
     async def pay_invoice(self, bolt11: str, fee_limit_msat: int) -> PaymentResponse:
         invoice = decode(bolt11)
 
-        if invoice.payment_hash[:6] == self.privkey[:6]:
+        if invoice.payment_hash[:6] == self.privkey[:6] or BRR:
             await self.queue.put(invoice)
             self.paid_invoices.add(invoice.payment_hash)
             return PaymentResponse(True, invoice.payment_hash, 0)
@@ -87,8 +89,7 @@ class FakeWallet(Wallet):
             )
 
     async def get_invoice_status(self, checking_id: str) -> PaymentStatus:
-
-        paid = checking_id in self.paid_invoices
+        paid = checking_id in self.paid_invoices or BRR
         return PaymentStatus(paid or None)
 
     async def get_payment_status(self, _: str) -> PaymentStatus:

cashu/mint/ledger.py

@@ -42,6 +42,7 @@ class Ledger:
         self.crud = crud
         self.lightning = lightning
         self.pubkey = derive_pubkey(self.master_key)
+        self.keysets = MintKeysets([])
 
     async def load_used_proofs(self):
         """Load all used proofs from database."""
@@ -86,11 +87,21 @@ class Ledger:
         """
         # load all past keysets from db
         tmp_keysets: List[MintKeyset] = await self.crud.get_keyset(db=self.db)
-        self.keysets = MintKeysets(tmp_keysets)
-        logger.trace(f"Loading {len(self.keysets.keysets)} keysets form db.")
-        # generate all derived keys from stored derivation paths of past keysets
+        # add keysets from db to current keysets
+        for k in tmp_keysets:
+            if k.id and k.id not in self.keysets.keysets:
+                self.keysets.keysets[k.id] = k
+
+        logger.debug(
+            f"Currently, there are {len(self.keysets.keysets)} active keysets."
+        )
+
+        # generate all private keys, public keys, and keyset id from the derivation path for all keysets that are not yet generated
         for _, v in self.keysets.keysets.items():
-            logger.trace(f"Generating keys for keyset {v.id}")
+            # we already generated the keys for this keyset
+            if v.id and v.public_keys and len(v.public_keys):
+                continue
+            logger.debug(f"Generating keys for keyset {v.id}")
             v.generate_keys(self.master_key)
         # load the current keyset
         self.keyset = await self.load_keyset(self.derivation_path, autosave)
@@ -128,6 +139,7 @@ class Ledger:
             BlindedSignature: Generated promise.
         """
         keyset = keyset if keyset else self.keyset
+        logger.trace(f"Generating promise with keyset {keyset.id}.")
         private_key_amount = keyset.private_keys[amount]
         C_ = b_dhke.step2_bob(B_, private_key_amount)
         await self.crud.store_promise(
@@ -155,6 +167,9 @@ class Ledger:
         if not proof.id:
             private_key_amount = self.keyset.private_keys[proof.amount]
         else:
+            logger.trace(
+                f"Validating proof with keyset {self.keysets.keysets[proof.id].id}."
+            )
             # use the appropriate active keyset for this proof.id
             private_key_amount = self.keysets.keysets[proof.id].private_keys[
                 proof.amount

cashu/mint/startup.py

@@ -1,6 +1,7 @@
 # startup routine of the standalone app. These are the steps that need
 # to be taken by external apps importing the cashu mint.
 
+import asyncio
 import importlib
 
 from loguru import logger
@@ -28,6 +29,20 @@ ledger = Ledger(
 )
 
 
+async def rotate_keys(n_seconds=10):
+    """Rotate keyset epoch every n_seconds.
+    Note: This is just a helper function for testing purposes.
+    """
+    i = 0
+    while True:
+        i += 1
+        logger.info("Rotating keys.")
+        ledger.derivation_path = f"0/0/0/{i}"
+        await ledger.init_keysets()
+        logger.info(f"Current keyset: {ledger.keyset.id}")
+        await asyncio.sleep(n_seconds)
+
+
 async def start_mint_init():
     await migrate_databases(ledger.db, migrations)
     await ledger.load_used_proofs()
@@ -45,3 +60,4 @@ async def start_mint_init():
 
     logger.info(f"Data dir: {settings.cashu_dir}")
     logger.info("Mint started.")
+    # asyncio.create_task(rotate_keys())