Merge pull request #55 from cashubtc/comments/add

comments

cashu/core/b_dhke.py

@@ -2,23 +2,28 @@
 
 """
 Implementation of https://gist.github.com/RubenSomsen/be7a4760dd4596d06963d67baf140406
-Alice:
+
+Alice (Client):
 A = a*G
 return A
-Bob:
+
+Bob (Mint):
 Y = hash_to_curve(secret_message)
 r = random blinding factor
 B'= Y + r*G
 return B'
+
 Alice:
 C' = a*B'
   (= a*Y + a*r*G)
 return C'
+
 Bob:
 C = C' - r*A
  (= C' - a*r*G)
  (= a*Y)
 return C, secret_message
+
 Alice:
 Y = hash_to_curve(secret_message)
 C == a*Y

cashu/core/base.py

@@ -14,7 +14,9 @@ class P2SHScript(BaseModel):
 
 
 class Proof(BaseModel):
-    id: Union[None, str] = ""
+    id: Union[
+        None, str
+    ] = ""  # NOTE: None for backwards compatibility of old clients < 0.3
     amount: int = 0
     secret: str = ""
     C: str = ""

cashu/core/legacy.py

@@ -4,8 +4,12 @@ from secp256k1 import PublicKey
 
 
 def hash_to_point_pre_0_3_3(secret_msg):
-    """Generates x coordinate from the message hash and checks if the point lies on the curve.
-    If it does not, it tries computing again a new x coordinate from the hash of the coordinate."""
+    """
+    NOTE: Clients pre 0.3.3 used a different hash_to_curve
+
+    Generates x coordinate from the message hash and checks if the point lies on the curve.
+    If it does not, it tries computing again a new x coordinate from the hash of the coordinate.
+    """
     point = None
     msg = secret_msg
     while point is None:

cashu/mint/router.py

@@ -104,8 +104,10 @@ async def split(
     """
     proofs = payload.proofs
     amount = payload.amount
+
+    # NOTE: backwards compatibility with clients < v0.2.2
     outputs = payload.outputs.blinded_messages if payload.outputs else None
-    # backwards compatibility with clients < v0.2.2
+
     assert outputs, Exception("no outputs provided.")
     try:
         split_return = await ledger.split(proofs, amount, outputs)