From 43de24d88c87706366bd26d124cc6859366f336d Mon Sep 17 00:00:00 2001
From: therealyingtong <yingtong@z.cash>
Date: Thu, 22 Apr 2021 13:29:28 +0800
Subject: [PATCH] Add Orchard generators

---
 orchard_generators.py | 61 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)
 create mode 100644 orchard_generators.py

diff --git a/orchard_generators.py b/orchard_generators.py
new file mode 100644
index 0000000..1737108
--- /dev/null
+++ b/orchard_generators.py
@@ -0,0 +1,61 @@
+#!/usr/bin/env python3
+import sys; assert sys.version_info[0] >= 3, "Python 3 required."
+
+from pyblake2 import blake2s
+
+from tv_output import render_args, render_tv
+from orchard_group_hash import group_hash
+from orchard_sinsemilla import sinsemilla_hash_to_point
+
+# https://zips.z.cash/protocol/nu5.pdf#concretespendauthsig
+SPENDING_KEY_BASE = group_hash(b'z.cash:Orchard', b'G')
+
+# https://zips.z.cash/protocol/nu5.pdf#commitmentsandnullifiers
+NULLIFIER_K_BASE = group_hash(b'z.cash:Orchard', b'K')
+
+# https://zips.z.cash/protocol/nu5.pdf#concretehomomorphiccommit
+VALUE_COMMITMENT_VALUE_BASE = group_hash(b'z.cash:Orchard-cv', b'v')
+VALUE_COMMITMENT_RANDOMNESS_BASE = group_hash(b'z.cash:Orchard-cv', b'r')
+
+# Used in SinsemillaCommit (https://zips.z.cash/protocol/nu5.pdf#sinsemillacommitments)
+NOTE_COMMITMENT_BASE = group_hash(b'z.cash:Orchard-NoteCommit-r', b'')
+NOTE_COMMITMENT_Q = group_hash(b'z.cash:Orchard-NoteCommit-M', b'')
+
+# Used in SinsemillaShortCommit (https://zips.z.cash/protocol/nu5.pdf#sinsemillacommitments)
+IVK_COMMITMENT_BASE = group_hash(b'z.cash:Orchard-CommitIvk-r', b'')
+IVK_COMMITMENT_Q = group_hash(b'z.cash:Orchard-CommitIvk-M', b'')
+
+# Used in SinsemillaHash (https://zips.z.cash/protocol/nu5.pdf#orchardmerklecrh)
+MERKLE_CRH_Q = group_hash(b'z.cash:Orchard-MerkleCRH', b'')
+
+def main():
+    render_tv(
+        render_args(),
+        'orchard_generators',
+        (
+            ('skb', '[u8; 32]'),
+            ('nkb', '[u8; 32]'),
+            ('vcvb', '[u8; 32]'),
+            ('vcrb', '[u8; 32]'),
+            ('cmb', '[u8; 32]'),
+            ('cmq', '[u8; 32]'),
+            ('ivkb', '[u8; 32]'),
+            ('ivkq', '[u8; 32]'),
+            ('mcq', '[u8; 32]'),
+        ),
+        {
+            'skb': bytes(SPENDING_KEY_BASE),
+            'nkb': bytes(NULLIFIER_K_BASE),
+            'vcvb': bytes(VALUE_COMMITMENT_VALUE_BASE),
+            'vcrb': bytes(VALUE_COMMITMENT_RANDOMNESS_BASE),
+            'cmb': bytes(NOTE_COMMITMENT_BASE),
+            'cmq': bytes(NOTE_COMMITMENT_Q),
+            'ivkb': bytes(IVK_COMMITMENT_BASE),
+            'ivkq': bytes(IVK_COMMITMENT_Q),
+            'mcq': bytes(MERKLE_CRH_Q),
+        },
+    )
+
+
+if __name__ == '__main__':
+    main()