5663800000879000000{"functions": ["privacy_transfer", "privacy_update", "privacy_init", "privacy_withdraw", "privacy_deposit"], "snippet": "# Paillier helpers + privacy transfer flow (ZIP23)\n\ndef _egcd(a, b):\n x0, y0 = 1, 0\n x1, y1 = 0, 1\n while b != 0:\n q = a // b\n a, b = b, a % b\n x0, x1 = x1, x0 - q * x1\n y0, y1 = y1, y0 - q * y1\n return a, x0, y0\n\ndef _modinv(a, n):\n g, x, _ = _egcd(a, n)\n assert g == 1\n return x % n\n\ndef _homomorphic_add(pub, c1, c2):\n n = pub\n n2 = n * n\n return (c1 * c2) % n2\n\ndef _homomorphic_sub(pub, c1, c2):\n n = pub\n n2 = n * n\n inv = _modinv(c2, n2)\n return (c1 * inv) % n2\n\n\n# Elliptic Curve parameters for secp256k1\nP = 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFFC2F\nA = 0\nB = 7\nGx = 55066263022277343669578718895168534326250603453777594175500187360389116729240\nGy = 32670510020758816978083085130507043184471273380659243275938904335757337482424\nG = (Gx, Gy)\nN = 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141\n\ndef _inverse_mod(k, p):\n if k == 0:\n raise\n return pow(k, p - 2, p)\n\ndef _is_on_curve(point):\n if point is None:\n return True\n x, y = point\n return (y * y - (x * x * x + A * x + B)) % P == 0\n\ndef _point_add(point1, point2):\n if point1 is None:\n return point2\n if point2 is None:\n return point1\n x1, y1 = point1\n x2, y2 = point2\n if x1 == x2 and y1 != y2:\n return None\n if x1 == x2:\n m = (3 * x1 * x1 + A) * _inverse_mod(2 * y1, P)\n else:\n m = (y2 - y1) * _inverse_mod(x2 - x1, P)\n m %= P\n x3 = (m * m - x1 - x2) % P\n y3 = (m * (x1 - x3) - y1) % P\n return (x3, y3)\n\ndef _scalar_mult(k, point):\n result = None\n addend = point\n while k:\n if k & 1:\n result = _point_add(result, addend)\n addend = _point_add(addend, addend)\n k >>= 1\n return result\n\ndef _ecdsa_verify(msg_hash_hex, signature_hex, public_key_hex):\n assert msg_hash_hex.startswith('0x')\n assert signature_hex.startswith('0x')\n assert public_key_hex.startswith('0x')\n r = int(signature_hex[2:66], 16)\n s = int(signature_hex[66:130], 16)\n if not (1 <= r < N and 1 <= s < N):\n return False\n point = (int(public_key_hex[2:66], 16), int(public_key_hex[66:], 16))\n e = int(msg_hash_hex[2:], 16)\n w = _inverse_mod(s, N)\n u1 = (e * w) % N\n u2 = (r * w) % N\n q = _point_add(_scalar_mult(u1, G), _scalar_mult(u2, point))\n if q is None:\n return False\n x, y = q\n return r == x % N\n\ndef _ecdsa_recover(msg_hash_hex, signature_hex):\n assert msg_hash_hex.startswith('0x')\n assert signature_hex.startswith('0x')\n r = int(signature_hex[2:66], 16)\n s = int(signature_hex[66:130], 16)\n z = int(msg_hash_hex[2:], 16)\n\n if len(signature_hex[2:]) == 130:\n v = int(signature_hex[130:], 16)\n if v >= 27:\n recovery_id = v - 27\n else:\n recovery_id = v\n recovery_ids = [recovery_id]\n else:\n recovery_ids = [0, 1]\n\n for recovery_id in recovery_ids:\n for j in range(2):\n x = r + j * N\n if x >= P:\n continue\n\n y_squared = (pow(x, 3, P) + A * x + B) % P\n y = pow(y_squared, (P + 1) // 4, P)\n\n if y % 2 != recovery_id:\n y = P - y\n\n point = (x, y)\n if not _is_on_curve(point):\n continue\n\n r_inv = _inverse_mod(r, N)\n u1 = (-z * r_inv) % N\n u2 = (s * r_inv) % N\n\n q = _point_add(_scalar_mult(u1, G), _scalar_mult(u2, point))\n\n if q is None:\n continue\n\n public_key_hex = f\"0x{q[0]:064x}{q[1]:064x}\"\n if _ecdsa_verify(msg_hash_hex, signature_hex, public_key_hex):\n return public_key_hex\n\n return None\n\ndef _pubkey_to_address(public_key_hex):\n public_key_bytes = bytes.fromhex(public_key_hex[2:])\n address_bytes = keccak(public_key_bytes)[-20:]\n return '0x' + address_bytes.hex()\n\ndef _message_hash(payload):\n payload_hash = keccak(text=payload)\n prefix = b\"\\x19Ethereum Signed Message:\\n32\"\n return keccak(prefix + payload_hash)\n\ndef _addr_recover(msg, signature_hex):\n if not signature_hex.startswith('0x'):\n signature_hex = '0x' + signature_hex\n msg_hash = _message_hash(msg)\n msg_hash_hex = msg_hash.hex()\n if not msg_hash_hex.startswith('0x'):\n msg_hash_hex = '0x' + msg_hash_hex\n public_key_hex = _ecdsa_recover(msg_hash_hex, signature_hex)\n if not public_key_hex:\n return False\n recovered = _pubkey_to_address(public_key_hex)\n return recovered.lower()\n\ndef _resolve_account(addr):\n addr = addr.lower()\n assert len(addr) <= 42\n if len(addr) == 42:\n assert addr.startswith('0x')\n assert set(addr[2:]) <= set(string.digits + 'abcdef')\n else:\n assert len(addr) > 4\n\n if len(addr) == 42:\n return handle_lookup(addr)\n return addr\n\ndef _check_tick(tick):\n assert type(tick) is str\n assert len(tick) > 0 and len(tick) < 42\n assert tick[0] in string.ascii_uppercase\n assert set(tick) <= set(string.ascii_uppercase + string.digits + '_')\n\n\ndef _get_pubkey(privacy_tick):\n pub, _ = get(privacy_tick, 'privacy_pub', None)\n if pub is None:\n return None\n return int(pub)\n\n\ndef privacy_init(info, args):\n assert args['f'] == 'privacy_init'\n\n tick = args['a'][0]\n _check_tick(tick)\n privacy_tick = args['a'][1]\n _check_tick(privacy_tick)\n provider_addr = args['a'][2]\n paillier_pub = int(args['a'][3])\n\n sender = info['sender']\n\n existing_provider, _ = get(privacy_tick, 'privacy_provider', None)\n assert existing_provider is None, \"Provider already initialized\"\n\n put(provider_addr, privacy_tick, 'tick', tick)\n put(provider_addr, privacy_tick, 'privacy_provider', provider_addr)\n put(provider_addr, privacy_tick, 'privacy_pub', int(paillier_pub))\n\n\ndef privacy_update(info, args):\n assert args['f'] == 'privacy_update'\n\n privacy_tick = args['a'][0]\n _check_tick(privacy_tick)\n owner, _ = get('asset', 'owner', None, privacy_tick)\n assert owner.lower() == info['sender'].lower(), f\"Only owner can update {privacy_tick}\"\n\n provider_addr = args['a'][1]\n assert provider_addr.startswith('0x') and len(provider_addr) == 42\n put(provider_addr, privacy_tick, 'privacy_provider', provider_addr.lower())\n\n paillier_pub = int(args['a'][3])\n put(provider_addr, privacy_tick, 'privacy_pub', int(paillier_pub))\n event('PrivacyUpdate', [privacy_tick, provider_addr])\n\n\ndef privacy_deposit(info, args):\n assert args['f'] == 'privacy_deposit'\n\n privacy_tick = args['a'][0]\n _check_tick(privacy_tick)\n tick, _ = get(privacy_tick, 'tick', None)\n _check_tick(tick)\n\n pub = _get_pubkey(privacy_tick)\n assert pub is not None\n\n functions, _ = get('asset', 'functions', [], tick)\n assert args['f'] in functions\n functions, _ = get('asset', 'functions', [], privacy_tick)\n assert args['f'] in functions\n\n sender = info['sender']\n addr = handle_lookup(sender)\n\n amount = int(args['a'][1])\n assert amount >= 0\n\n amount_cipher = int(args['a'][2])\n assert amount_cipher >= 0\n\n nonce = int(args['a'][3])\n assert nonce >= 0\n\n signature_hex = args['a'][4]\n assert signature_hex.startswith('0x')\n\n stored_nonce, _ = get(privacy_tick,'privacy_nonce', 0, sender)\n assert nonce == stored_nonce + 1\n put(sender, privacy_tick, 'privacy_nonce', nonce, sender)\n\n provider_addr, _ = get(privacy_tick, 'privacy_provider', None)\n msg_to_sign = f'{privacy_tick},privacy_deposit,{str(amount)},{str(amount_cipher)},{str(nonce)}'\n\n recovered_addr = _addr_recover(msg_to_sign, signature_hex)\n assert provider_addr.lower() == recovered_addr, \"Invalid signature\"\n\n total_supply, _ = get(privacy_tick, 'total_supply', 0)\n put(provider_addr, privacy_tick, 'total_supply', int(total_supply) + amount)\n\n balance, _ = get(tick, 'balance', 0, f'{sender}')\n assert balance >= amount\n balance_updated = balance - amount\n put(addr, tick, 'balance', balance_updated, addr)\n\n pool_balance, _ = get(tick, 'balance', 0, privacy_tick)\n put(privacy_tick, tick, 'balance', int(pool_balance) + amount, privacy_tick)\n\n balance_cipher, _ = get(privacy_tick, 'privacy_balance', 1, addr)\n balance_cipher_updated = _homomorphic_add(pub, int(balance_cipher), amount_cipher)\n put(sender, privacy_tick, 'privacy_balance', balance_cipher_updated, sender)\n event('PrivacyDeposit', [privacy_tick, addr, amount, amount_cipher, nonce])\n\n\ndef privacy_withdraw(info, args):\n assert args['f'] == 'privacy_withdraw'\n\n privacy_tick = args['a'][0]\n _check_tick(privacy_tick)\n functions, _ = get('asset', 'functions', [], privacy_tick)\n assert args['f'] in functions\n\n tick, _ = get(privacy_tick, 'tick', None)\n _check_tick(tick)\n\n amount = int(args['a'][1])\n assert amount > 0\n amount_cipher = int(args['a'][2])\n assert amount_cipher > 0\n old_balance_cipher = int(args['a'][3])\n assert old_balance_cipher > 0\n nonce = int(args['a'][4]) \n signature = args['a'][5]\n\n sender = info['sender'].lower()\n\n provider_addr, _ = get(privacy_tick, 'privacy_provider', None)\n assert provider_addr is not None, \"Provider not initialized\"\n\n stored_nonce, _ = get(privacy_tick,'privacy_nonce', 0, sender)\n assert nonce == int(stored_nonce) + 1, \"Invalid nonce\"\n\n msg = f\"{privacy_tick},privacy_withdraw,{sender},{nonce},{amount},{amount_cipher},{old_balance_cipher}\"\n recovered_addr = _addr_recover(msg, signature)\n assert recovered_addr == provider_addr.lower(), \"Invalid signature\"\n\n pub = _get_pubkey(privacy_tick)\n assert pub is not None\n\n stored_balance, _ = get(privacy_tick, 'privacy_balance', 1, sender)\n assert int(stored_balance) == old_balance_cipher, \"State mismatch\"\n\n total_supply, _ = get(privacy_tick, 'total_supply', 0)\n new_total = int(total_supply) - amount\n assert new_total >= 0, \"Insufficent total supply\"\n\n new_balance_cipher = _homomorphic_sub(pub, int(stored_balance), amount_cipher)\n\n put(sender, privacy_tick, 'privacy_balance', new_balance_cipher, sender)\n put(sender, privacy_tick, 'privacy_nonce', nonce, sender)\n put(provider_addr, privacy_tick, 'total_supply', new_total)\n\n pool_balance, _ = get(tick, 'balance', 0, privacy_tick)\n put(privacy_tick, tick, 'balance', int(pool_balance) - amount, privacy_tick)\n\n user_balance, _ = get(tick, 'balance', 0, sender)\n put(sender, tick, 'balance', int(user_balance) + amount, sender)\n\n event('PrivacyWithdraw', [sender, amount, new_balance_cipher, nonce])\n\n\ndef privacy_transfer(info,args):\n assert args['f'] == 'privacy_transfer'\n privacy_tick= args['a'][0]\n _check_tick(privacy_tick)\n\n functions, _ = get('asset', 'functions', [], privacy_tick)\n assert args['f'] in functions\n\n to_addr = args['a'][1].lower()\n amount_cipher = int(args['a'][2])\n assert amount_cipher > 0\n\n nonce = int(args['a'][3])\n assert nonce > 0\n signature = args['a'][4]\n assert signature.startswith('0x')\n\n sender = info['sender'].lower() \n assert sender != to_addr, \"Self-transfer not allowed\"\n\n provider_addr, _ = get(privacy_tick, 'privacy_provider', None)\n assert provider_addr is not None, \"Provider not initialized\"\n pub = _get_pubkey(privacy_tick)\n assert pub is not None\n\n msg = f\"{privacy_tick},privacy_transfer,{sender},{to_addr},{nonce},{amount_cipher}\"\n recovered_addr = _addr_recover(msg, signature)\n assert recovered_addr == provider_addr.lower(), \"Invalid provider signature\"\n\n current_sender_bal, _ = get(privacy_tick, 'privacy_balance', 1, sender)\n current_receiver_bal, _ = get(privacy_tick, 'privacy_balance', 1, to_addr)\n\n stored_nonce, _ = get(privacy_tick, 'privacy_nonce', 0, sender)\n assert nonce == int(stored_nonce) + 1, \"Invalid nonce\"\n\n new_sender_bal = _homomorphic_sub(pub, int(current_sender_bal), amount_cipher)\n new_receiver_bal = _homomorphic_add(pub, int(current_receiver_bal), amount_cipher)\n\n put(sender, privacy_tick, 'privacy_balance', new_sender_bal, sender)\n put(sender, privacy_tick, 'privacy_nonce', nonce, sender)\n put(to_addr, privacy_tick, 'privacy_balance', new_receiver_bal, to_addr)\n\n event('PrivacyTransfer', [sender, to_addr, amount_cipher, nonce])\n\n"}{"votes": [], "snippets": ["c1258f735d7d3928490e6008dcaebdd308a55ac77dab1818d6a480cf3c6d360e"], "functions": ["privacy_init", "privacy_update", "privacy_deposit", "privacy_transfer", "privacy_withdraw"]}{"functions": ["privacy_transfer", "privacy_update", "privacy_init", "privacy_withdraw", "privacy_deposit"], "snippet": "# Paillier helpers + privacy transfer flow (ZIP23)\n\ndef _egcd(a, b):\n x0, y0 = 1, 0\n x1, y1 = 0, 1\n while b != 0:\n q = a // b\n a, b = b, a % b\n x0, x1 = x1, x0 - q * x1\n y0, y1 = y1, y0 - q * y1\n return a, x0, y0\n\ndef _modinv(a, n):\n g, x, _ = _egcd(a, n)\n assert g == 1\n return x % n\n\ndef _homomorphic_add(pub, c1, c2):\n n = pub\n n2 = n * n\n return (c1 * c2) % n2\n\ndef _homomorphic_sub(pub, c1, c2):\n n = pub\n n2 = n * n\n inv = _modinv(c2, n2)\n return (c1 * inv) % n2\n\n\n# Elliptic Curve parameters for secp256k1\nP = 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFFC2F\nA = 0\nB = 7\nGx = 55066263022277343669578718895168534326250603453777594175500187360389116729240\nGy = 32670510020758816978083085130507043184471273380659243275938904335757337482424\nG = (Gx, Gy)\nN = 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141\n\ndef _inverse_mod(k, p):\n if k == 0:\n raise\n return pow(k, p - 2, p)\n\ndef _is_on_curve(point):\n if point is None:\n return True\n x, y = point\n return (y * y - (x * x * x + A * x + B)) % P == 0\n\ndef _point_add(point1, point2):\n if point1 is None:\n return point2\n if point2 is None:\n return point1\n x1, y1 = point1\n x2, y2 = point2\n if x1 == x2 and y1 != y2:\n return None\n if x1 == x2:\n m = (3 * x1 * x1 + A) * _inverse_mod(2 * y1, P)\n else:\n m = (y2 - y1) * _inverse_mod(x2 - x1, P)\n m %= P\n x3 = (m * m - x1 - x2) % P\n y3 = (m * (x1 - x3) - y1) % P\n return (x3, y3)\n\ndef _scalar_mult(k, point):\n result = None\n addend = point\n while k:\n if k & 1:\n result = _point_add(result, addend)\n addend = _point_add(addend, addend)\n k >>= 1\n return result\n\ndef _ecdsa_verify(msg_hash_hex, signature_hex, public_key_hex):\n assert msg_hash_hex.startswith('0x')\n assert signature_hex.startswith('0x')\n assert public_key_hex.startswith('0x')\n r = int(signature_hex[2:66], 16)\n s = int(signature_hex[66:130], 16)\n if not (1 <= r < N and 1 <= s < N):\n return False\n point = (int(public_key_hex[2:66], 16), int(public_key_hex[66:], 16))\n e = int(msg_hash_hex[2:], 16)\n w = _inverse_mod(s, N)\n u1 = (e * w) % N\n u2 = (r * w) % N\n q = _point_add(_scalar_mult(u1, G), _scalar_mult(u2, point))\n if q is None:\n return False\n x, y = q\n return r == x % N\n\ndef _ecdsa_recover(msg_hash_hex, signature_hex):\n assert msg_hash_hex.startswith('0x')\n assert signature_hex.startswith('0x')\n r = int(signature_hex[2:66], 16)\n s = int(signature_hex[66:130], 16)\n z = int(msg_hash_hex[2:], 16)\n\n if len(signature_hex[2:]) == 130:\n v = int(signature_hex[130:], 16)\n if v >= 27:\n recovery_id = v - 27\n else:\n recovery_id = v\n recovery_ids = [recovery_id]\n else:\n recovery_ids = [0, 1]\n\n for recovery_id in recovery_ids:\n for j in range(2):\n x = r + j * N\n if x >= P:\n continue\n\n y_squared = (pow(x, 3, P) + A * x + B) % P\n y = pow(y_squared, (P + 1) // 4, P)\n\n if y % 2 != recovery_id:\n y = P - y\n\n point = (x, y)\n if not _is_on_curve(point):\n continue\n\n r_inv = _inverse_mod(r, N)\n u1 = (-z * r_inv) % N\n u2 = (s * r_inv) % N\n\n q = _point_add(_scalar_mult(u1, G), _scalar_mult(u2, point))\n\n if q is None:\n continue\n\n public_key_hex = f\"0x{q[0]:064x}{q[1]:064x}\"\n if _ecdsa_verify(msg_hash_hex, signature_hex, public_key_hex):\n return public_key_hex\n\n return None\n\ndef _pubkey_to_address(public_key_hex):\n public_key_bytes = bytes.fromhex(public_key_hex[2:])\n address_bytes = keccak(public_key_bytes)[-20:]\n return '0x' + address_bytes.hex()\n\ndef _message_hash(payload):\n payload_hash = keccak(text=payload)\n prefix = b\"\\x19Ethereum Signed Message:\\n32\"\n return keccak(prefix + payload_hash)\n\ndef _addr_recover(msg, signature_hex):\n if not signature_hex.startswith('0x'):\n signature_hex = '0x' + signature_hex\n msg_hash = _message_hash(msg)\n msg_hash_hex = msg_hash.hex()\n if not msg_hash_hex.startswith('0x'):\n msg_hash_hex = '0x' + msg_hash_hex\n public_key_hex = _ecdsa_recover(msg_hash_hex, signature_hex)\n if not public_key_hex:\n return False\n recovered = _pubkey_to_address(public_key_hex)\n return recovered.lower()\n\ndef _resolve_account(addr):\n addr = addr.lower()\n assert len(addr) <= 42\n if len(addr) == 42:\n assert addr.startswith('0x')\n assert set(addr[2:]) <= set(string.digits + 'abcdef')\n else:\n assert len(addr) > 4\n\n if len(addr) == 42:\n return handle_lookup(addr)\n return addr\n\ndef _check_tick(tick):\n assert type(tick) is str\n assert len(tick) > 0 and len(tick) < 42\n assert tick[0] in string.ascii_uppercase\n assert set(tick) <= set(string.ascii_uppercase + string.digits + '_')\n\n\ndef _get_pubkey(privacy_tick):\n pub, _ = get(privacy_tick, 'privacy_pub', None)\n if pub is None:\n return None\n return int(pub)\n\n\ndef privacy_init(info, args):\n assert args['f'] == 'privacy_init'\n\n tick = args['a'][0]\n _check_tick(tick)\n privacy_tick = args['a'][1]\n _check_tick(privacy_tick)\n provider_addr = args['a'][2]\n paillier_pub = int(args['a'][3])\n\n sender = info['sender']\n\n existing_provider, _ = get(privacy_tick, 'privacy_provider', None)\n assert existing_provider is None, \"Provider already initialized\"\n\n put(provider_addr, privacy_tick, 'tick', tick)\n put(provider_addr, privacy_tick, 'privacy_provider', provider_addr)\n put(provider_addr, privacy_tick, 'privacy_pub', int(paillier_pub))\n\n\ndef privacy_update(info, args):\n assert args['f'] == 'privacy_update'\n\n privacy_tick = args['a'][0]\n _check_tick(privacy_tick)\n owner, _ = get('asset', 'owner', None, privacy_tick)\n assert owner.lower() == info['sender'].lower(), f\"Only owner can update {privacy_tick}\"\n\n provider_addr = args['a'][1]\n assert provider_addr.startswith('0x') and len(provider_addr) == 42\n put(provider_addr, privacy_tick, 'privacy_provider', provider_addr.lower())\n\n paillier_pub = int(args['a'][2])\n put(provider_addr, privacy_tick, 'privacy_pub', int(paillier_pub))\n event('PrivacyUpdate', [privacy_tick, provider_addr])\n\n\ndef privacy_deposit(info, args):\n assert args['f'] == 'privacy_deposit'\n\n privacy_tick = args['a'][0]\n _check_tick(privacy_tick)\n tick, _ = get(privacy_tick, 'tick', None)\n _check_tick(tick)\n\n pub = _get_pubkey(privacy_tick)\n assert pub is not None\n\n functions, _ = get('asset', 'functions', [], tick)\n assert args['f'] in functions\n functions, _ = get('asset', 'functions', [], privacy_tick)\n assert args['f'] in functions\n\n sender = info['sender']\n addr = handle_lookup(sender)\n\n amount = int(args['a'][1])\n assert amount >= 0\n\n amount_cipher = int(args['a'][2])\n assert amount_cipher >= 0\n\n nonce = int(args['a'][3])\n assert nonce >= 0\n\n signature_hex = args['a'][4]\n assert signature_hex.startswith('0x')\n\n stored_nonce, _ = get(privacy_tick,'privacy_nonce', 0, sender)\n assert nonce == stored_nonce + 1\n put(sender, privacy_tick, 'privacy_nonce', nonce, sender)\n\n provider_addr, _ = get(privacy_tick, 'privacy_provider', None)\n msg_to_sign = f'{privacy_tick},privacy_deposit,{str(amount)},{str(amount_cipher)},{str(nonce)}'\n\n recovered_addr = _addr_recover(msg_to_sign, signature_hex)\n assert provider_addr.lower() == recovered_addr, \"Invalid signature\"\n\n total_supply, _ = get(privacy_tick, 'total_supply', 0)\n put(provider_addr, privacy_tick, 'total_supply', int(total_supply) + amount)\n\n balance, _ = get(tick, 'balance', 0, f'{sender}')\n assert balance >= amount\n balance_updated = balance - amount\n put(addr, tick, 'balance', balance_updated, addr)\n\n pool_balance, _ = get(tick, 'balance', 0, privacy_tick)\n put(privacy_tick, tick, 'balance', int(pool_balance) + amount, privacy_tick)\n\n balance_cipher, _ = get(privacy_tick, 'privacy_balance', 1, addr)\n balance_cipher_updated = _homomorphic_add(pub, int(balance_cipher), amount_cipher)\n put(sender, privacy_tick, 'privacy_balance', balance_cipher_updated, sender)\n event('PrivacyDeposit', [privacy_tick, addr, amount, amount_cipher, nonce])\n\n\ndef privacy_withdraw(info, args):\n assert args['f'] == 'privacy_withdraw'\n\n privacy_tick = args['a'][0]\n _check_tick(privacy_tick)\n functions, _ = get('asset', 'functions', [], privacy_tick)\n assert args['f'] in functions\n\n tick, _ = get(privacy_tick, 'tick', None)\n _check_tick(tick)\n\n amount = int(args['a'][1])\n assert amount > 0\n amount_cipher = int(args['a'][2])\n assert amount_cipher > 0\n old_balance_cipher = int(args['a'][3])\n assert old_balance_cipher > 0\n nonce = int(args['a'][4]) \n signature = args['a'][5]\n\n sender = info['sender'].lower()\n\n provider_addr, _ = get(privacy_tick, 'privacy_provider', None)\n assert provider_addr is not None, \"Provider not initialized\"\n\n stored_nonce, _ = get(privacy_tick,'privacy_nonce', 0, sender)\n assert nonce == int(stored_nonce) + 1, \"Invalid nonce\"\n\n msg = f\"{privacy_tick},privacy_withdraw,{sender},{nonce},{amount},{amount_cipher},{old_balance_cipher}\"\n recovered_addr = _addr_recover(msg, signature)\n assert recovered_addr == provider_addr.lower(), \"Invalid signature\"\n\n pub = _get_pubkey(privacy_tick)\n assert pub is not None\n\n stored_balance, _ = get(privacy_tick, 'privacy_balance', 1, sender)\n assert int(stored_balance) == old_balance_cipher, \"State mismatch\"\n\n total_supply, _ = get(privacy_tick, 'total_supply', 0)\n new_total = int(total_supply) - amount\n assert new_total >= 0, \"Insufficent total supply\"\n\n new_balance_cipher = _homomorphic_sub(pub, int(stored_balance), amount_cipher)\n\n put(sender, privacy_tick, 'privacy_balance', new_balance_cipher, sender)\n put(sender, privacy_tick, 'privacy_nonce', nonce, sender)\n put(provider_addr, privacy_tick, 'total_supply', new_total)\n\n pool_balance, _ = get(tick, 'balance', 0, privacy_tick)\n put(privacy_tick, tick, 'balance', int(pool_balance) - amount, privacy_tick)\n\n user_balance, _ = get(tick, 'balance', 0, sender)\n put(sender, tick, 'balance', int(user_balance) + amount, sender)\n\n event('PrivacyWithdraw', [sender, amount, new_balance_cipher, nonce])\n\n\ndef privacy_transfer(info,args):\n assert args['f'] == 'privacy_transfer'\n privacy_tick= args['a'][0]\n _check_tick(privacy_tick)\n\n functions, _ = get('asset', 'functions', [], privacy_tick)\n assert args['f'] in functions\n\n to_addr = args['a'][1].lower()\n amount_cipher = int(args['a'][2])\n assert amount_cipher > 0\n\n nonce = int(args['a'][3])\n assert nonce > 0\n signature = args['a'][4]\n assert signature.startswith('0x')\n\n sender = info['sender'].lower() \n assert sender != to_addr, \"Self-transfer not allowed\"\n\n provider_addr, _ = get(privacy_tick, 'privacy_provider', None)\n assert provider_addr is not None, \"Provider not initialized\"\n pub = _get_pubkey(privacy_tick)\n assert pub is not None\n\n msg = f\"{privacy_tick},privacy_transfer,{sender},{to_addr},{nonce},{amount_cipher}\"\n recovered_addr = _addr_recover(msg, signature)\n assert recovered_addr == provider_addr.lower(), \"Invalid provider signature\"\n\n current_sender_bal, _ = get(privacy_tick, 'privacy_balance', 1, sender)\n current_receiver_bal, _ = get(privacy_tick, 'privacy_balance', 1, to_addr)\n\n stored_nonce, _ = get(privacy_tick, 'privacy_nonce', 0, sender)\n assert nonce == int(stored_nonce) + 1, \"Invalid nonce\"\n\n new_sender_bal = _homomorphic_sub(pub, int(current_sender_bal), amount_cipher)\n new_receiver_bal = _homomorphic_add(pub, int(current_receiver_bal), amount_cipher)\n\n put(sender, privacy_tick, 'privacy_balance', new_sender_bal, sender)\n put(sender, privacy_tick, 'privacy_nonce', nonce, sender)\n put(to_addr, privacy_tick, 'privacy_balance', new_receiver_bal, to_addr)\n\n event('PrivacyTransfer', [sender, to_addr, amount_cipher, nonce])\n\n"}{"votes": [], "snippets": ["87d011c775bee494ce3352db264d3c99bbef8dd4c51344d5e3055c15821bedda"], "functions": ["privacy_init", "privacy_update", "privacy_deposit", "privacy_transfer", "privacy_withdraw"]}355472994681606545144990922383471081839520286886436144032884673911782299187828036699558275842912452688686675351623657932857174406103599988219831900019094944872886976477988935858548983385549086830385084038547800337515552427283640578526004367655726343996443383153777948385077587890587856215709039554541847241135219076045683535804670472216840751395571693883989305110217000988789001817701470433765839358672626528327776397550098918076599929077995397666965523234921508392065407241815399716923052966845698423763288406299652917385011081903151853762651451353091233459926374561846190457959269505531550652598007851049485400833410{"functions": ["privacy_transfer", "privacy_update", "privacy_init", "privacy_withdraw", "privacy_deposit"], "snippet": "# Paillier helpers + privacy transfer flow (ZIP23)\n\ndef _egcd(a, b):\n x0, y0 = 1, 0\n x1, y1 = 0, 1\n while b != 0:\n q = a // b\n a, b = b, a % b\n x0, x1 = x1, x0 - q * x1\n y0, y1 = y1, y0 - q * y1\n return a, x0, y0\n\ndef _modinv(a, n):\n g, x, _ = _egcd(a, n)\n assert g == 1\n return x % n\n\ndef _homomorphic_add(pub, c1, c2):\n n = pub\n n2 = n * n\n return (c1 * c2) % n2\n\ndef _homomorphic_sub(pub, c1, c2):\n n = pub\n n2 = n * n\n inv = _modinv(c2, n2)\n return (c1 * inv) % n2\n\n\n# Elliptic Curve parameters for secp256k1\nP = 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFFC2F\nA = 0\nB = 7\nGx = 55066263022277343669578718895168534326250603453777594175500187360389116729240\nGy = 32670510020758816978083085130507043184471273380659243275938904335757337482424\nG = (Gx, Gy)\nN = 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141\n\ndef _inverse_mod(k, p):\n if k == 0:\n raise\n return pow(k, p - 2, p)\n\ndef _is_on_curve(point):\n if point is None:\n return True\n x, y = point\n return (y * y - (x * x * x + A * x + B)) % P == 0\n\ndef _point_add(point1, point2):\n if point1 is None:\n return point2\n if point2 is None:\n return point1\n x1, y1 = point1\n x2, y2 = point2\n if x1 == x2 and y1 != y2:\n return None\n if x1 == x2:\n m = (3 * x1 * x1 + A) * _inverse_mod(2 * y1, P)\n else:\n m = (y2 - y1) * _inverse_mod(x2 - x1, P)\n m %= P\n x3 = (m * m - x1 - x2) % P\n y3 = (m * (x1 - x3) - y1) % P\n return (x3, y3)\n\ndef _scalar_mult(k, point):\n result = None\n addend = point\n while k:\n if k & 1:\n result = _point_add(result, addend)\n addend = _point_add(addend, addend)\n k >>= 1\n return result\n\ndef _ecdsa_verify(msg_hash_hex, signature_hex, public_key_hex):\n assert msg_hash_hex.startswith('0x')\n assert signature_hex.startswith('0x')\n assert public_key_hex.startswith('0x')\n r = int(signature_hex[2:66], 16)\n s = int(signature_hex[66:130], 16)\n if not (1 <= r < N and 1 <= s < N):\n return False\n point = (int(public_key_hex[2:66], 16), int(public_key_hex[66:], 16))\n e = int(msg_hash_hex[2:], 16)\n w = _inverse_mod(s, N)\n u1 = (e * w) % N\n u2 = (r * w) % N\n q = _point_add(_scalar_mult(u1, G), _scalar_mult(u2, point))\n if q is None:\n return False\n x, y = q\n return r == x % N\n\ndef _ecdsa_recover(msg_hash_hex, signature_hex):\n assert msg_hash_hex.startswith('0x')\n assert signature_hex.startswith('0x')\n r = int(signature_hex[2:66], 16)\n s = int(signature_hex[66:130], 16)\n z = int(msg_hash_hex[2:], 16)\n\n if len(signature_hex[2:]) == 130:\n v = int(signature_hex[130:], 16)\n if v >= 27:\n recovery_id = v - 27\n else:\n recovery_id = v\n recovery_ids = [recovery_id]\n else:\n recovery_ids = [0, 1]\n\n for recovery_id in recovery_ids:\n for j in range(2):\n x = r + j * N\n if x >= P:\n continue\n\n y_squared = (pow(x, 3, P) + A * x + B) % P\n y = pow(y_squared, (P + 1) // 4, P)\n\n if y % 2 != recovery_id:\n y = P - y\n\n point = (x, y)\n if not _is_on_curve(point):\n continue\n\n r_inv = _inverse_mod(r, N)\n u1 = (-z * r_inv) % N\n u2 = (s * r_inv) % N\n\n q = _point_add(_scalar_mult(u1, G), _scalar_mult(u2, point))\n\n if q is None:\n continue\n\n public_key_hex = f\"0x{q[0]:064x}{q[1]:064x}\"\n if _ecdsa_verify(msg_hash_hex, signature_hex, public_key_hex):\n return public_key_hex\n\n return None\n\ndef _pubkey_to_address(public_key_hex):\n public_key_bytes = bytes.fromhex(public_key_hex[2:])\n address_bytes = keccak(public_key_bytes)[-20:]\n return '0x' + address_bytes.hex()\n\ndef _message_hash(payload):\n payload_hash = keccak(text=payload)\n prefix = b\"\\x19Ethereum Signed Message:\\n32\"\n return keccak(prefix + payload_hash)\n\ndef _addr_recover(msg, signature_hex):\n if not signature_hex.startswith('0x'):\n signature_hex = '0x' + signature_hex\n msg_hash = _message_hash(msg)\n msg_hash_hex = msg_hash.hex()\n if not msg_hash_hex.startswith('0x'):\n msg_hash_hex = '0x' + msg_hash_hex\n public_key_hex = _ecdsa_recover(msg_hash_hex, signature_hex)\n if not public_key_hex:\n return False\n recovered = _pubkey_to_address(public_key_hex)\n return recovered.lower()\n\ndef _resolve_account(addr):\n addr = addr.lower()\n assert len(addr) <= 42\n if len(addr) == 42:\n assert addr.startswith('0x')\n assert set(addr[2:]) <= set(string.digits + 'abcdef')\n else:\n assert len(addr) > 4\n\n if len(addr) == 42:\n return handle_lookup(addr)\n return addr\n\ndef _check_tick(tick):\n assert type(tick) is str\n assert len(tick) > 0 and len(tick) < 42\n assert tick[0] in string.ascii_uppercase\n assert set(tick) <= set(string.ascii_uppercase + string.digits + '_')\n\n\ndef _get_pubkey(privacy_tick):\n pub, _ = get(privacy_tick, 'privacy_pub', None)\n if pub is None:\n return None\n return int(pub)\n\n\ndef privacy_init(info, args):\n assert args['f'] == 'privacy_init'\n\n tick = args['a'][0]\n _check_tick(tick)\n privacy_tick = args['a'][1]\n _check_tick(privacy_tick)\n provider_addr = args['a'][2]\n paillier_pub = int(args['a'][3])\n\n sender = info['sender']\n\n existing_provider, _ = get(privacy_tick, 'privacy_provider', None)\n assert existing_provider is None, \"Provider already initialized\"\n\n put(provider_addr, privacy_tick, 'tick', tick)\n put(provider_addr, privacy_tick, 'privacy_provider', provider_addr)\n put(provider_addr, privacy_tick, 'privacy_pub', int(paillier_pub))\n\n\ndef privacy_update(info, args):\n assert args['f'] == 'privacy_update'\n\n privacy_tick = args['a'][0]\n _check_tick(privacy_tick)\n owner, _ = get('asset', 'owner', None, privacy_tick)\n assert owner.lower() == info['sender'].lower(), f\"Only owner can update {privacy_tick}\"\n\n provider_addr = args['a'][1]\n assert provider_addr.startswith('0x') and len(provider_addr) == 42\n put(provider_addr, privacy_tick, 'privacy_provider', provider_addr.lower())\n\n paillier_pub = int(args['a'][2])\n put(provider_addr, privacy_tick, 'privacy_pub', int(paillier_pub))\n event('PrivacyUpdate', [privacy_tick, provider_addr])\n\n\ndef privacy_deposit(info, args):\n assert args['f'] == 'privacy_deposit'\n\n privacy_tick = args['a'][0]\n _check_tick(privacy_tick)\n tick, _ = get(privacy_tick, 'tick', None)\n _check_tick(tick)\n\n pub = _get_pubkey(privacy_tick)\n assert pub is not None\n\n functions, _ = get('asset', 'functions', [], tick)\n assert args['f'] in functions\n functions, _ = get('asset', 'functions', [], privacy_tick)\n assert args['f'] in functions\n\n sender = info['sender']\n addr = handle_lookup(sender)\n\n amount = int(args['a'][1])\n assert amount >= 0\n\n amount_cipher = int(args['a'][2])\n assert amount_cipher >= 0\n\n nonce = int(args['a'][3])\n assert nonce >= 0\n\n signature_hex = args['a'][4]\n assert signature_hex.startswith('0x')\n\n stored_nonce, _ = get(privacy_tick,'privacy_nonce', 0, sender)\n assert nonce == stored_nonce + 1\n put(sender, privacy_tick, 'privacy_nonce', nonce, sender)\n\n provider_addr, _ = get(privacy_tick, 'privacy_provider', None)\n msg_to_sign = f'{privacy_tick},privacy_deposit,{sender},{nonce},{amount},{amount_cipher}'\n\n recovered_addr = _addr_recover(msg_to_sign, signature_hex)\n assert provider_addr.lower() == recovered_addr, \"Invalid signature\"\n\n total_supply, _ = get(privacy_tick, 'total_supply', 0)\n put(provider_addr, privacy_tick, 'total_supply', int(total_supply) + amount)\n\n balance, _ = get(tick, 'balance', 0, f'{sender}')\n assert balance >= amount\n balance_updated = balance - amount\n put(addr, tick, 'balance', balance_updated, addr)\n\n pool_balance, _ = get(tick, 'balance', 0, privacy_tick)\n put(privacy_tick, tick, 'balance', int(pool_balance) + amount, privacy_tick)\n\n balance_cipher, _ = get(privacy_tick, 'privacy_balance', 1, addr)\n balance_cipher_updated = _homomorphic_add(pub, int(balance_cipher), amount_cipher)\n put(sender, privacy_tick, 'privacy_balance', balance_cipher_updated, sender)\n event('PrivacyDeposit', [privacy_tick, addr, amount, amount_cipher, nonce])\n\n\ndef privacy_withdraw(info, args):\n assert args['f'] == 'privacy_withdraw'\n\n privacy_tick = args['a'][0]\n _check_tick(privacy_tick)\n functions, _ = get('asset', 'functions', [], privacy_tick)\n assert args['f'] in functions\n\n tick, _ = get(privacy_tick, 'tick', None)\n _check_tick(tick)\n\n amount = int(args['a'][1])\n assert amount > 0\n amount_cipher = int(args['a'][2])\n assert amount_cipher > 0\n old_balance_cipher = int(args['a'][3])\n assert old_balance_cipher > 0\n nonce = int(args['a'][4]) \n signature = args['a'][5]\n\n sender = info['sender'].lower()\n\n provider_addr, _ = get(privacy_tick, 'privacy_provider', None)\n assert provider_addr is not None, \"Provider not initialized\"\n\n stored_nonce, _ = get(privacy_tick,'privacy_nonce', 0, sender)\n assert nonce == int(stored_nonce) + 1, \"Invalid nonce\"\n\n msg = f\"{privacy_tick},privacy_withdraw,{sender},{nonce},{amount},{amount_cipher},{old_balance_cipher}\"\n recovered_addr = _addr_recover(msg, signature)\n assert recovered_addr == provider_addr.lower(), \"Invalid signature\"\n\n pub = _get_pubkey(privacy_tick)\n assert pub is not None\n\n stored_balance, _ = get(privacy_tick, 'privacy_balance', 1, sender)\n assert int(stored_balance) == old_balance_cipher, \"State mismatch\"\n\n total_supply, _ = get(privacy_tick, 'total_supply', 0)\n new_total = int(total_supply) - amount\n assert new_total >= 0, \"Insufficent total supply\"\n\n new_balance_cipher = _homomorphic_sub(pub, int(stored_balance), amount_cipher)\n\n put(sender, privacy_tick, 'privacy_balance', new_balance_cipher, sender)\n put(sender, privacy_tick, 'privacy_nonce', nonce, sender)\n put(provider_addr, privacy_tick, 'total_supply', new_total)\n\n pool_balance, _ = get(tick, 'balance', 0, privacy_tick)\n put(privacy_tick, tick, 'balance', int(pool_balance) - amount, privacy_tick)\n\n user_balance, _ = get(tick, 'balance', 0, sender)\n put(sender, tick, 'balance', int(user_balance) + amount, sender)\n\n event('PrivacyWithdraw', [sender, amount, new_balance_cipher, nonce])\n\n\ndef privacy_transfer(info,args):\n assert args['f'] == 'privacy_transfer'\n privacy_tick= args['a'][0]\n _check_tick(privacy_tick)\n\n functions, _ = get('asset', 'functions', [], privacy_tick)\n assert args['f'] in functions\n\n to_addr = args['a'][1].lower()\n amount_cipher = int(args['a'][2])\n assert amount_cipher > 0\n\n nonce = int(args['a'][3])\n assert nonce > 0\n signature = args['a'][4]\n assert signature.startswith('0x')\n\n sender = info['sender'].lower() \n assert sender != to_addr, \"Self-transfer not allowed\"\n\n provider_addr, _ = get(privacy_tick, 'privacy_provider', None)\n assert provider_addr is not None, \"Provider not initialized\"\n pub = _get_pubkey(privacy_tick)\n assert pub is not None\n\n msg = f\"{privacy_tick},privacy_transfer,{sender},{to_addr},{nonce},{amount_cipher}\"\n recovered_addr = _addr_recover(msg, signature)\n assert recovered_addr == provider_addr.lower(), \"Invalid provider signature\"\n\n current_sender_bal, _ = get(privacy_tick, 'privacy_balance', 1, sender)\n current_receiver_bal, _ = get(privacy_tick, 'privacy_balance', 1, to_addr)\n\n stored_nonce, _ = get(privacy_tick, 'privacy_nonce', 0, sender)\n assert nonce == int(stored_nonce) + 1, \"Invalid nonce\"\n\n new_sender_bal = _homomorphic_sub(pub, int(current_sender_bal), amount_cipher)\n new_receiver_bal = _homomorphic_add(pub, int(current_receiver_bal), amount_cipher)\n\n put(sender, privacy_tick, 'privacy_balance', new_sender_bal, sender)\n put(sender, privacy_tick, 'privacy_nonce', nonce, sender)\n put(to_addr, privacy_tick, 'privacy_balance', new_receiver_bal, to_addr)\n\n event('PrivacyTransfer', [sender, to_addr, amount_cipher, nonce])\n\n"}{"votes": [], "snippets": ["a019cf76656b7d0f127f65846453fa43f9d911cfefafb464f71663b42c162256"], "functions": ["privacy_init", "privacy_update", "privacy_deposit", "privacy_transfer", "privacy_withdraw"]}1875404380591891789499560432334125985703147284146216687009396356973470104982854301052043306613860954390438536028523813743165566473090907664815666345938265816195966882750056249854358453175072036386191093402340511658243535605209707440136367776676042060946906143179674929677777719131763704245487700439159381468070216368517458604610412092390583624283806044054480005677609627864824658772114741036123706745531290462307976851976069946345124967633455576745976926582597798910873765779514481138067338791964495803384383668510217566810920323688361143271649761199651420118916317076998605428126787635247314504230169135509085404987730282767193309723654719109950025318326706352027464349242583641943790537483937968275952931736718418874060133781608268938436966730950310073344095463228278645365354726032729413961359118872298925406301184835356465805607350447338469901669648403079684530486321877028252007611983710031002184165229661285578428211946049086617678959501728233225831797640162209625951477277455357461980812081035976378846283790122297529371713564291047962448093937359515833207004793852023964797316630921159111340988792300208838978457557666331287070901365093055000608550763303377041053137258277648593562769612942695404076826039949137906803341753190839198072766201106816424635166497401249517148920249837933862994965450507475611622079032941650047303538565148122732344247829237319859091984876274406338105972972964422879151055685228113570888622595635053022863814730141529303738629247737250797259675392094878076776738441141272049598262807423667597254884430285492318526383292869018497260660043688592203865118746620395778742857386323194503856175635732248398695367640777902866132978557983995478755740822719129455191544253125082924423272495115296710643727759331483845693242502543144887197814753236381942591108187624149974699176608887459517660197407381687013290814695404878572848564658558359013525302541691589440897905436619663065157999599691397787841898763514331143369366679107992036472936541535531076823752805463103308726164579129893497981599738654585344357176897126888390672443290059973601968977726684100006149979159598580494331324937063493130301428041527253661583906851277942342243828703468312169961169121361637722536950316347972690337879124809354425002551439831100598034144272573521978858593919532664485937933009629112512773546918002376992441254006225034661335691258941339681449494684700255359919408728395497752441404538304910311625859430852490163631616433451030376745278876449300528657316478878054661277841003462796046751781053553908411837713183344199492274265076117346072401596980454758201168527406183397162064046194801929388900863575451015422060204684532388612322891487021774509128945531249980031047748450201712955192976759907749981896693122379138662483565445538690076500674961855748344119728914665125645871761083675418629351771233944956219171837351660105783473719242075634183245822509348088212263283548951797491593476120071855617959115744249786566868715731239263049826221026308744526198250316659284987607426777312063063574427950617950019325432398816916226280264469493726625707623453639210202756776773634714481191723147773028740827008667567992707016108684955732093508678956429036008460487832834967777353221041784563802951654587021719229246092196929250435801180085127719337208578345224777017691409029626427106161608924197033267033832461682030587022797088633751289566359081881962318330898773592272662866276815624488742472165213704616897014259756197263760071636998899162166610517480769942032130549275592239908324951367444079463721582866233042232532803772220390991846795971414370887288468427403403681674917178128117119910683480015802667728654541082258539126515879589397699314832907440167650043229906045520121836504312{"functions": ["privacy_transfer", "privacy_reset", "privacy_update", "privacy_init", "privacy_withdraw", "privacy_deposit"], "snippet": "# Paillier helpers + privacy transfer flow (ZIP23)\n\ndef _egcd(a, b):\n x0, y0 = 1, 0\n x1, y1 = 0, 1\n while b != 0:\n q = a // b\n a, b = b, a % b\n x0, x1 = x1, x0 - q * x1\n y0, y1 = y1, y0 - q * y1\n return a, x0, y0\n\ndef _modinv(a, n):\n g, x, _ = _egcd(a, n)\n assert g == 1\n return x % n\n\ndef _homomorphic_add(pub, c1, c2):\n n = pub\n n2 = n * n\n return (c1 * c2) % n2\n\ndef _homomorphic_sub(pub, c1, c2):\n n = pub\n n2 = n * n\n inv = _modinv(c2, n2)\n return (c1 * inv) % n2\n\n\n# Elliptic Curve parameters for secp256k1\nP = 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFFC2F\nA = 0\nB = 7\nGx = 55066263022277343669578718895168534326250603453777594175500187360389116729240\nGy = 32670510020758816978083085130507043184471273380659243275938904335757337482424\nG = (Gx, Gy)\nN = 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141\n\ndef _inverse_mod(k, p):\n if k == 0:\n raise\n return pow(k, p - 2, p)\n\ndef _is_on_curve(point):\n if point is None:\n return True\n x, y = point\n return (y * y - (x * x * x + A * x + B)) % P == 0\n\ndef _point_add(point1, point2):\n if point1 is None:\n return point2\n if point2 is None:\n return point1\n x1, y1 = point1\n x2, y2 = point2\n if x1 == x2 and y1 != y2:\n return None\n if x1 == x2:\n m = (3 * x1 * x1 + A) * _inverse_mod(2 * y1, P)\n else:\n m = (y2 - y1) * _inverse_mod(x2 - x1, P)\n m %= P\n x3 = (m * m - x1 - x2) % P\n y3 = (m * (x1 - x3) - y1) % P\n return (x3, y3)\n\ndef _scalar_mult(k, point):\n result = None\n addend = point\n while k:\n if k & 1:\n result = _point_add(result, addend)\n addend = _point_add(addend, addend)\n k >>= 1\n return result\n\ndef _ecdsa_verify(msg_hash_hex, signature_hex, public_key_hex):\n assert msg_hash_hex.startswith('0x')\n assert signature_hex.startswith('0x')\n assert public_key_hex.startswith('0x')\n r = int(signature_hex[2:66], 16)\n s = int(signature_hex[66:130], 16)\n if not (1 <= r < N and 1 <= s < N):\n return False\n point = (int(public_key_hex[2:66], 16), int(public_key_hex[66:], 16))\n e = int(msg_hash_hex[2:], 16)\n w = _inverse_mod(s, N)\n u1 = (e * w) % N\n u2 = (r * w) % N\n q = _point_add(_scalar_mult(u1, G), _scalar_mult(u2, point))\n if q is None:\n return False\n x, y = q\n return r == x % N\n\ndef _ecdsa_recover(msg_hash_hex, signature_hex):\n assert msg_hash_hex.startswith('0x')\n assert signature_hex.startswith('0x')\n r = int(signature_hex[2:66], 16)\n s = int(signature_hex[66:130], 16)\n z = int(msg_hash_hex[2:], 16)\n\n if len(signature_hex[2:]) == 130:\n v = int(signature_hex[130:], 16)\n if v >= 27:\n recovery_id = v - 27\n else:\n recovery_id = v\n recovery_ids = [recovery_id]\n else:\n recovery_ids = [0, 1]\n\n for recovery_id in recovery_ids:\n for j in range(2):\n x = r + j * N\n if x >= P:\n continue\n\n y_squared = (pow(x, 3, P) + A * x + B) % P\n y = pow(y_squared, (P + 1) // 4, P)\n\n if y % 2 != recovery_id:\n y = P - y\n\n point = (x, y)\n if not _is_on_curve(point):\n continue\n\n r_inv = _inverse_mod(r, N)\n u1 = (-z * r_inv) % N\n u2 = (s * r_inv) % N\n\n q = _point_add(_scalar_mult(u1, G), _scalar_mult(u2, point))\n\n if q is None:\n continue\n\n public_key_hex = f\"0x{q[0]:064x}{q[1]:064x}\"\n if _ecdsa_verify(msg_hash_hex, signature_hex, public_key_hex):\n return public_key_hex\n\n return None\n\ndef _pubkey_to_address(public_key_hex):\n public_key_bytes = bytes.fromhex(public_key_hex[2:])\n address_bytes = keccak(public_key_bytes)[-20:]\n return '0x' + address_bytes.hex()\n\ndef _message_hash(payload):\n payload_hash = keccak(text=payload)\n prefix = b\"\\x19Ethereum Signed Message:\\n32\"\n return keccak(prefix + payload_hash)\n\ndef _addr_recover(msg, signature_hex):\n if not signature_hex.startswith('0x'):\n signature_hex = '0x' + signature_hex\n msg_hash = _message_hash(msg)\n msg_hash_hex = msg_hash.hex()\n if not msg_hash_hex.startswith('0x'):\n msg_hash_hex = '0x' + msg_hash_hex\n public_key_hex = _ecdsa_recover(msg_hash_hex, signature_hex)\n if not public_key_hex:\n return False\n recovered = _pubkey_to_address(public_key_hex)\n return recovered.lower()\n\ndef _resolve_account(addr):\n addr = addr.lower()\n assert len(addr) <= 42\n if len(addr) == 42:\n assert addr.startswith('0x')\n assert set(addr[2:]) <= set(string.digits + 'abcdef')\n else:\n assert len(addr) > 4\n\n if len(addr) == 42:\n return handle_lookup(addr)\n return addr\n\ndef _check_tick(tick):\n assert type(tick) is str\n assert len(tick) > 0 and len(tick) < 42\n assert tick[0] in string.ascii_uppercase\n assert set(tick) <= set(string.ascii_uppercase + string.digits + '_')\n\n\ndef _get_pubkey(privacy_tick):\n pub, _ = get(privacy_tick, 'privacy_pub', None)\n if pub is None:\n return None\n return int(pub)\n\n\ndef privacy_init(info, args):\n assert args['f'] == 'privacy_init'\n\n tick = args['a'][0]\n _check_tick(tick)\n privacy_tick = args['a'][1]\n _check_tick(privacy_tick)\n provider_addr = args['a'][2]\n paillier_pub = int(args['a'][3])\n\n sender = info['sender']\n\n existing_provider, _ = get(privacy_tick, 'privacy_provider', None)\n assert existing_provider is None, \"Provider already initialized\"\n\n put(provider_addr, privacy_tick, 'tick', tick)\n put(provider_addr, privacy_tick, 'privacy_provider', provider_addr)\n put(provider_addr, privacy_tick, 'privacy_pub', int(paillier_pub))\n\n\ndef privacy_update(info, args):\n assert args['f'] == 'privacy_update'\n\n privacy_tick = args['a'][0]\n _check_tick(privacy_tick)\n owner, _ = get('asset', 'owner', None, privacy_tick)\n assert owner.lower() == info['sender'].lower(), f\"Only owner can update {privacy_tick}\"\n\n provider_addr = args['a'][1]\n assert provider_addr.startswith('0x') and len(provider_addr) == 42\n put(provider_addr, privacy_tick, 'privacy_provider', provider_addr.lower())\n\n paillier_pub = int(args['a'][2])\n put(provider_addr, privacy_tick, 'privacy_pub', int(paillier_pub))\n event('PrivacyUpdate', [privacy_tick, provider_addr])\n\n\ndef privacy_deposit(info, args):\n assert args['f'] == 'privacy_deposit'\n\n privacy_tick = args['a'][0]\n _check_tick(privacy_tick)\n tick, _ = get(privacy_tick, 'tick', None)\n _check_tick(tick)\n\n pub = _get_pubkey(privacy_tick)\n assert pub is not None\n\n functions, _ = get('asset', 'functions', [], tick)\n assert args['f'] in functions\n functions, _ = get('asset', 'functions', [], privacy_tick)\n assert args['f'] in functions\n\n sender = info['sender']\n addr = handle_lookup(sender)\n\n amount = int(args['a'][1])\n assert amount >= 0\n\n amount_cipher = int(args['a'][2])\n assert amount_cipher >= 0\n\n nonce = int(args['a'][3])\n assert nonce >= 0\n\n signature_hex = args['a'][4]\n assert signature_hex.startswith('0x')\n\n stored_nonce, _ = get(privacy_tick, 'privacy_nonce', 0, sender)\n assert nonce == stored_nonce + 1\n put(sender, privacy_tick, 'privacy_nonce', nonce, sender)\n\n provider_addr, _ = get(privacy_tick, 'privacy_provider', None)\n msg_to_sign = f'{privacy_tick},privacy_deposit,{sender},{nonce},{amount},{amount_cipher}'\n\n recovered_addr = _addr_recover(msg_to_sign, signature_hex)\n assert provider_addr.lower() == recovered_addr, \"Invalid signature\"\n\n total_supply, _ = get(privacy_tick, 'total_supply', 0)\n put(provider_addr, privacy_tick, 'total_supply', int(total_supply) + amount)\n\n balance, _ = get(tick, 'balance', 0, f'{sender}')\n assert balance >= amount\n balance_updated = balance - amount\n put(addr, tick, 'balance', balance_updated, addr)\n\n pool_balance, _ = get(tick, 'balance', 0, privacy_tick)\n put(privacy_tick, tick, 'balance', int(pool_balance) + amount, privacy_tick)\n\n balance_cipher, _ = get(privacy_tick, 'privacy_balance', 1, addr)\n balance_cipher_updated = _homomorphic_add(pub, int(balance_cipher), amount_cipher)\n put(sender, privacy_tick, 'privacy_balance', balance_cipher_updated, sender)\n event('PrivacyDeposit', [privacy_tick, addr, amount, amount_cipher, nonce])\n\n\ndef privacy_withdraw(info, args):\n assert args['f'] == 'privacy_withdraw'\n\n privacy_tick = args['a'][0]\n _check_tick(privacy_tick)\n functions, _ = get('asset', 'functions', [], privacy_tick)\n assert args['f'] in functions\n\n tick, _ = get(privacy_tick, 'tick', None)\n _check_tick(tick)\n\n amount = int(args['a'][1])\n assert amount > 0\n amount_cipher = int(args['a'][2])\n assert amount_cipher > 0\n old_balance_cipher = int(args['a'][3])\n assert old_balance_cipher > 0\n nonce = int(args['a'][4]) \n signature = args['a'][5]\n\n sender = info['sender']\n\n provider_addr, _ = get(privacy_tick, 'privacy_provider', None)\n assert provider_addr is not None, \"Provider not initialized\"\n\n stored_nonce, _ = get(privacy_tick,'privacy_nonce', 0, sender)\n assert nonce == int(stored_nonce) + 1, \"Invalid nonce\"\n\n msg = f\"{privacy_tick},privacy_withdraw,{sender},{nonce},{amount},{amount_cipher},{old_balance_cipher}\"\n recovered_addr = _addr_recover(msg, signature)\n assert recovered_addr == provider_addr.lower(), \"Invalid signature\"\n\n pub = _get_pubkey(privacy_tick)\n assert pub is not None\n\n stored_balance, _ = get(privacy_tick, 'privacy_balance', 1, sender)\n assert int(stored_balance) == old_balance_cipher, \"State mismatch\"\n\n total_supply, _ = get(privacy_tick, 'total_supply', 0)\n new_total = int(total_supply) - amount\n assert new_total >= 0, \"Insufficent total supply\"\n\n new_balance_cipher = _homomorphic_sub(pub, int(stored_balance), amount_cipher)\n\n put(sender, privacy_tick, 'privacy_balance', new_balance_cipher, sender)\n put(sender, privacy_tick, 'privacy_nonce', nonce, sender)\n put(provider_addr, privacy_tick, 'total_supply', new_total)\n\n pool_balance, _ = get(tick, 'balance', 0, privacy_tick)\n put(privacy_tick, tick, 'balance', int(pool_balance) - amount, privacy_tick)\n\n user_balance, _ = get(tick, 'balance', 0, sender)\n put(sender, tick, 'balance', int(user_balance) + amount, sender)\n\n event('PrivacyWithdraw', [sender, amount, new_balance_cipher, nonce])\n\n\ndef privacy_transfer(info,args):\n assert args['f'] == 'privacy_transfer'\n privacy_tick = args['a'][0]\n _check_tick(privacy_tick)\n\n functions, _ = get('asset', 'functions', [], privacy_tick)\n assert args['f'] in functions\n\n to_addr = args['a'][1].lower()\n amount_cipher = int(args['a'][2])\n assert amount_cipher > 0\n\n nonce = int(args['a'][3])\n assert nonce > 0\n signature = args['a'][4]\n assert signature.startswith('0x')\n\n sender = info['sender']\n assert sender != to_addr, \"Self-transfer not allowed\"\n\n provider_addr, _ = get(privacy_tick, 'privacy_provider', None)\n assert provider_addr is not None, \"Provider not initialized\"\n pub = _get_pubkey(privacy_tick)\n assert pub is not None\n\n msg = f\"{privacy_tick},privacy_transfer,{sender},{to_addr},{nonce},{amount_cipher}\"\n recovered_addr = _addr_recover(msg, signature)\n assert recovered_addr == provider_addr.lower(), \"Invalid provider signature\"\n\n current_sender_bal, _ = get(privacy_tick, 'privacy_balance', 1, sender)\n current_receiver_bal, _ = get(privacy_tick, 'privacy_balance', 1, to_addr)\n\n stored_nonce, _ = get(privacy_tick, 'privacy_nonce', 0, sender)\n assert nonce == int(stored_nonce) + 1, \"Invalid nonce\"\n\n new_sender_bal = _homomorphic_sub(pub, int(current_sender_bal), amount_cipher)\n new_receiver_bal = _homomorphic_add(pub, int(current_receiver_bal), amount_cipher)\n\n put(sender, privacy_tick, 'privacy_balance', new_sender_bal, sender)\n put(sender, privacy_tick, 'privacy_nonce', nonce, sender)\n put(to_addr, privacy_tick, 'privacy_balance', new_receiver_bal, to_addr)\n\n event('PrivacyTransfer', [sender, to_addr, amount_cipher, nonce])\n\n"}{"functions": ["privacy_transfer", "privacy_reset", "privacy_update", "privacy_init", "privacy_withdraw", "privacy_deposit"], "snippet": "\ndef privacy_reset(info, args):\n assert args['f'] == 'privacy_reset'\n sender = info['sender']\n put(sender, 'PUSDC', 'privacy_balance', 1, sender)\n event('PrivacyReset', [sender])\n\n"}{"votes": [], "snippets": ["2e3f7fcf48f9c178aa5520c60d147ef15c69272048a10138f6fee7db4741981b", "b6335de3a510c47060240296fc5f433024a727ebb2e63fb5c7c8f5ee3ce7c871"], "functions": ["privacy_init", "privacy_update", "privacy_deposit", "privacy_transfer", "privacy_withdraw", "privacy_reset"]}{"snippets": ["2e3f7fcf48f9c178aa5520c60d147ef15c69272048a10138f6fee7db4741981b", "b6335de3a510c47060240296fc5f433024a727ebb2e63fb5c7c8f5ee3ce7c871"]}727722149832389411799686564538231457401295048390094651613106916244266614200163296561305826457311522757100361502105189056318621996221801714712338152851779010672620701929240895380314319173693269930878141948527648516041678096288917313474422463665624622297436881715147838238180247558425997268161992334614784491292083051979295188632626484356494081119007327677431818414903920317598905362938686456752315474514644043319931847331511459637696987843864768426469036449209383456603839123449870621370136526632615609549871041822002464328563314553131623474761637820102094959808166302996196058422140405733013825169661533188824564361819876500