Merge pull request #10 from str4d/zip0243-spend-rk

Update ZIP 243 test vectors with valid rk values

sapling_generators.py

@@ -23,7 +23,7 @@ def group_hash(D, M):
     digest.update(URS)
     digest.update(M)
     p = Point.from_bytes(digest.digest())
-    if not p:
+    if p is None:
         return None
     q = p * JUBJUB_COFACTOR
     if q == Point.ZERO:
@@ -34,7 +34,7 @@ def find_group_hash(D, M):
     i = 0
     while True:
         p = group_hash(D, M + bytes([i]))
-        if p:
+        if p is not None:
             return p
         i += 1
         assert i < 256

sapling_jubjub.py

@@ -142,6 +142,14 @@ JUBJUB_D = Fq(-10240) / Fq(10241)
 JUBJUB_COFACTOR = Fr(8)
 
 class Point(object):
+    @staticmethod
+    def rand(rand):
+        while True:
+            data = rand.b(32)
+            p = Point.from_bytes(data)
+            if p is not None:
+                return p
+
     @staticmethod
     def from_bytes(buf):
         assert len(buf) == 32
@@ -156,7 +164,7 @@ class Point(object):
         u2 = (vv - Fq.ONE) / (vv * JUBJUB_D - JUBJUB_A)
 
         u = u2.sqrt()
-        if not u:
+        if u is None:
             return None
 
         if u.s % 2 != u_sign:

transaction.py

@@ -2,7 +2,7 @@
 import struct
 
 from sapling_generators import find_group_hash, SPENDING_KEY_BASE
-from sapling_jubjub import Fq
+from sapling_jubjub import Fq, Point
 from sapling_utils import leos2ip
 from zc_utils import write_compact_size
 
@@ -80,7 +80,7 @@ class SpendDescription(object):
         self.cv = find_group_hash(b'TVRandPt', rand.b(32))
         self.anchor = Fq(leos2ip(rand.b(32)))
         self.nullifier = rand.b(32)
-        self.rk = rand.b(32)
+        self.rk = Point.rand(rand)
         self.proof = GrothProof(rand)
         self.spendAuthSig = rand.b(64) # Invalid
 
@@ -89,7 +89,7 @@ class SpendDescription(object):
             bytes(self.cv) +
             bytes(self.anchor) +
             self.nullifier +
-            self.rk +
+            bytes(self.rk) +
             bytes(self.proof) +
             self.spendAuthSig
         )
@@ -221,6 +221,7 @@ class Transaction(object):
 
         self.nLockTime = rand.u32()
         self.nExpiryHeight = rand.u32() % TX_EXPIRY_HEIGHT_THRESHOLD
+        if self.nVersion >= SAPLING_TX_VERSION:
             self.valueBalance = rand.u64() % (MAX_MONEY + 1)
 
         self.vShieldedSpends = []
@@ -239,6 +240,7 @@ class Transaction(object):
                 self.joinSplitPubKey = rand.b(32) # Potentially invalid
                 self.joinSplitSig = rand.b(64) # Invalid
 
+        if self.nVersion >= SAPLING_TX_VERSION:
             self.bindingSig = rand.b(64) # Invalid
 
     def header(self):

zip_0143.py

@@ -156,7 +156,7 @@ def main():
                 'rust_fmt': lambda x: None if x == -1 else Some(x),
                 }),
             ('hash_type', 'u32'),
-            ('amount', 'u64'),
+            ('amount', 'i64'),
             ('consensus_branch_id', 'u32'),
             ('sighash', '[u8; 32]'),
         ),

zip_0243.py

@@ -31,7 +31,7 @@ def getHashShieldedSpends(tx):
         digest.update(bytes(desc.cv))
         digest.update(bytes(desc.anchor))
         digest.update(desc.nullifier)
-        digest.update(desc.rk)
+        digest.update(bytes(desc.rk))
         digest.update(bytes(desc.proof))
     return digest.digest()
 
@@ -163,7 +163,7 @@ def main():
                 'rust_fmt': lambda x: None if x == -1 else Some(x),
                 }),
             ('hash_type', 'u32'),
-            ('amount', 'u64'),
+            ('amount', 'i64'),
             ('consensus_branch_id', 'u32'),
             ('sighash', '[u8; 32]'),
         ),