Add Codex vuln detector

The detector requires:
- The user to use the flag `--codex` (meaning that codex is not ran by default)
- `openai` must be installed, and `OPENAI_API_KEY` set

The detector works at the contract level, and send the whole contract body to codex

setup.py

@@ -26,6 +26,7 @@
             "deepdiff",
             "numpy",
             "solc-select>=v1.0.0b1",
+            "openai"
         ]
     },
     license="AGPL-3.0",

slither/__main__.py

@@ -301,6 +301,10 @@ def parse_args(
 
     parser.add_argument("filename", help=argparse.SUPPRESS)
 
+    parser.add_argument(
+        "--codex", help="Enable codex (require an OpenAI API Key)", action="store_true", default=False
+    )
+
     cryticparser.init(parser)
 
     parser.add_argument(

slither/detectors/all_detectors.py

@@ -85,3 +85,4 @@
 from .statements.delegatecall_in_loop import DelegatecallInLoop
 from .functions.protected_variable import ProtectedVariables
 from .functions.permit_domain_signature_collision import DomainSeparatorCollision
+from .functions.codex import Codex

slither/detectors/functions/codex.py

@@ -0,0 +1,80 @@
+import logging
+import os
+from typing import List
+
+from slither.detectors.abstract_detector import AbstractDetector, DetectorClassification
+from slither.utils.output import Output
+
+logger = logging.getLogger("Slither")
+
+
+class Codex(AbstractDetector):
+    """
+    Use codex to detect vulnerability
+    """
+
+    ARGUMENT = "codex"
+    HELP = "Use Codex to find vulnerabilities."
+    IMPACT = DetectorClassification.HIGH
+    CONFIDENCE = DetectorClassification.LOW
+
+    WIKI = "https://github.com/crytic/slither/wiki/Detector-Documentation#codex"
+
+    WIKI_TITLE = "Codex"
+    WIKI_DESCRIPTION = "Use [codex](https://openai.com/blog/openai-codex/) to find vulnerabilities"
+
+    # region wiki_exploit_scenario
+    WIKI_EXPLOIT_SCENARIO = """N/A"""
+    # endregion wiki_exploit_scenario
+
+    WIKI_RECOMMENDATION = "Review codex's message."
+
+    def _detect(self) -> List[Output]:
+        results: List[Output] = []
+
+        if not self.slither.codex_enabled:
+            return []
+
+        try:
+            # pylint: disable=import-outside-toplevel
+            import openai
+        except ImportError:
+            logging.info("OpenAI was not installed")
+            logging.info('run "pip install openai"')
+            return []
+
+        api_key = os.getenv("OPENAI_API_KEY")
+        if api_key is None:
+            logging.info(
+                "Please provide an Open API Key in OPENAI_API_KEY (https://beta.openai.com/account/api-keys)"
+            )
+            return []
+        openai.api_key = api_key
+
+        for contract in self.compilation_unit.contracts:
+            prompt = "Is there a vulnerability in this solidity contracts?\n"
+            src_mapping = contract.source_mapping
+            content = contract.compilation_unit.core.source_code[src_mapping.filename.absolute]
+            start = src_mapping.start
+            end = src_mapping.start + src_mapping.length
+            prompt += content[start:end]
+            answer = openai.Completion.create(  # type: ignore
+                model="text-davinci-003", prompt=prompt, temperature=0, max_tokens=200
+            )
+
+            if "choices" in answer:
+                if answer["choices"]:
+                    if "text" in answer["choices"][0]:
+                        if "Yes," in answer["choices"][0]["text"]:
+                            info = [
+                                "Codex detected a potential bug in ",
+                                contract,
+                                "\n",
+                                answer["choices"][0]["text"],
+                                "\n",
+                            ]
+
+                            res = self.generate_result(info)
+                            results.append(res)
+
+        return results

slither/slither.py

@@ -83,6 +83,9 @@ def __init__(self, target: Union[str, CryticCompile], **kwargs):
 
         self.line_prefix = kwargs.get("change_line_prefix", "#")
 
+        # Indicate if codex-related features should be used
+        self.codex_enabled = kwargs.get("codex", False)
+
         self._parsers: List[SlitherCompilationUnitSolc] = []
         try:
             if isinstance(target, CryticCompile):