From 15955dcbae1ad6781c46ffa1f6d8c0c6a47081b6 Mon Sep 17 00:00:00 2001
From: Arthur B <a@b.c>
Date: Wed, 21 Mar 2018 14:59:09 +0100
Subject: [PATCH] Alpha: genesis block allocation script

---
 scripts/create_genesis/create_genesis_info.py | 96 +++++++++++++++++++
 scripts/create_genesis/requirements.txt       |  3 +
 2 files changed, 99 insertions(+)
 create mode 100755 scripts/create_genesis/create_genesis_info.py
 create mode 100644 scripts/create_genesis/requirements.txt

diff --git a/scripts/create_genesis/create_genesis_info.py b/scripts/create_genesis/create_genesis_info.py
new file mode 100755
index 000000000..f7e9f81af
--- /dev/null
+++ b/scripts/create_genesis/create_genesis_info.py
@@ -0,0 +1,96 @@
+#! /usr/bin/env python
+
+import sys
+import os
+import json
+import bitcoin
+import binascii
+import numpy as np
+import pysodium
+from pyblake2 import blake2b
+
+def tez_to_int(amount):
+    return int(round(amount * 1e6, 0))
+
+def allocate_with_subthreshold( w ):
+    from_ether = sum(x[u'tezzies'] for x in w[u'ethDeposits'])
+    def discount_level( level ):
+        if level >= 2000:
+            return 0
+        return 6000 - (level/400)*250
+    from_bitcoin = sum(x[u'satoshis'] * discount_level(x[u'crowdfund_level']) for x in w[u'utxos'])
+    return from_ether + from_bitcoin * 1e-8
+
+def get_wallets(path):
+    wallets = {}
+    for fn in os.listdir(path):
+        # ignore misc files
+        if not fn.startswith("tz1"):
+            continue
+        w = json.load(open(os.path.join(path, fn), "r"))
+        # if not u'allocated_tezzies' in w.keys():
+        #    continue
+        wallets[fn.split(".")[0]] = allocate_with_subthreshold(w)
+    return wallets
+
+def secret_code(pkh, blind):
+    return blake2b(pkh, 20, key=blind).digest()
+
+def genesis_commitments(wallets, blind):
+    commitments = []
+    for pkh_b58, amount in wallets.iteritems():
+        # Public key hash corresponding to this Tezos address.
+        pkh = bitcoin.b58check_to_bin(pkh_b58)[2:]
+        # The redemption code is unique to the public key hash and deterministically
+        # constructed using a secret blinding value.
+        secret = secret_code(pkh, blind)
+        # The redemption code is used to blind the pkh
+        blinded_pkh = blake2b(pkh, 20, key=secret).digest()
+        commitment = {
+            'half_pkh': binascii.hexlify(pkh[:10]),
+            'blinded_pkh': binascii.hexlify(blinded_pkh),
+            'amount': tez_to_int(amount)
+        }
+        commitments.append(commitment)
+    return commitments
+
+# Generate dummy genesis information for a centralized alphanet faucet
+def make_dummy_wallets(n, blind):
+    # Not a realistic shape, but for an alphanet faucet it's better to
+    # have less variance.
+    amounts = np.random.pareto(10.0, n)
+    amounts = amounts / sum(amounts) * 760e6
+    wallets = {}
+    secret_seeds = {}
+    for i in range(0, n):
+        seed = blake2b(str(i), 32, key=blind).digest()
+        pk, sk = pysodium.crypto_sign_seed_keypair(seed)
+        pkh = blake2b(pk, 20).digest()
+        pkh_b58 = bitcoin.bin_to_b58check(pkh, magicbyte=434591)
+        amount = tez_to_int(amounts[i])
+        wallets[pkh_b58] = amount
+        secret = secret_code(pkh, blind)
+        secret_seeds[pkh_b58] = (bitcoin.bin_to_b58check(seed, magicbyte=219101703), amount, binascii.hexlify(secret))
+    return wallets, secret_seeds
+
+if __name__ == '__main__':
+    if len(sys.argv) < 3:
+        print "Usage: python create_genesis_info.py /path/to/json blind [dummy]"
+        exit(1)
+    blind = sys.argv[2]
+    if len(sys.argv) == 4 and sys.argv[3] == "dummy":
+        wallets, secret_seeds = make_dummy_wallets(30000, blind)
+        with open('secret_seeds.json', 'w') as f:
+            json.dump([(pkh, sk, a, r) for pkh, (sk, a, r) in secret_seeds.iteritems()], f, indent=1)
+    else:
+        wallets = get_wallets( sys.argv[1] )
+
+    commitments = genesis_commitments(wallets, blind)
+
+    print "let commitments = ["
+    print ";\n".join([ '"%s", "%s", %d' %
+                       ( commitment['half_pkh'],
+                         commitment['blinded_pkh'],
+                         commitment['amount'] )
+                       for commitment in commitments if commitment['amount'] > 0])
+    print "]"
diff --git a/scripts/create_genesis/requirements.txt b/scripts/create_genesis/requirements.txt
new file mode 100644
index 000000000..d3da7afb8
--- /dev/null
+++ b/scripts/create_genesis/requirements.txt
@@ -0,0 +1,3 @@
+-e git+https://github.com/vbuterin/pybitcointools.git@aeb0a2bbb8bbfe421432d776c649650eaeb882a5#egg=master
+pyblake2==0.9.3
+pysodium==0.6.11