Add aeg.cipher(alg) for loading modules by name in str. Added aeg.CIPHERS mapping of the nominal names to module names and Cipher for typing literals.

tools/generate.py

@@ -273,6 +273,23 @@ def generate_python_modules(
     return updated, unchanged
 
 
+def generate_ciphers_module(constants: Dict[str, Dict[str, int]]) -> str:
+    labels = [algo_label(variant) for variant in constants]
+    literal_items = ", ".join(f'"{label}"' for label in labels)
+    lines = [
+        "# This file is generated by tools/generate.py. Do not edit.",
+        "from typing import Literal",
+        "",
+        f"CipherName = Literal[{literal_items}]",
+        "",
+        "CIPHERS: dict[CipherName, str] = {",
+    ]
+    for variant in constants:
+        lines.append(f'    "{algo_label(variant)}": "{variant}",')
+    lines.append("}")
+    return "\n".join(lines) + "\n"
+
+
 def main() -> int:
     root = pathlib.Path(__file__).parent.parent
     libaegis_src_dir = root / "libaegis" / "src"
@@ -304,7 +321,20 @@ def main() -> int:
         cdef_path.write_bytes(cdef_content.encode())
         print(f"  - Updated {cdef_path}", file=sys.stderr)
 
-    print("Step 3: Generating Python modules...", file=sys.stderr)
+    print("Step 3: Generating _ciphers.py...", file=sys.stderr)
+    ciphers_path = pyaegis_dir / "_ciphers.py"
+    ciphers_content = generate_ciphers_module(constants)
+
+    if (
+        ciphers_path.exists()
+        and ciphers_path.read_text(encoding="utf-8") == ciphers_content
+    ):
+        print(f"  - No changes to {ciphers_path.name}", file=sys.stderr)
+    else:
+        ciphers_path.write_bytes(ciphers_content.encode())
+        print(f"  - Updated {ciphers_path.name}", file=sys.stderr)
+
+    print("Step 4: Generating Python modules...", file=sys.stderr)
     try:
         updated, unchanged = generate_python_modules(
             pyaegis_dir / "aegis256x4.py", pyaegis_dir, constants