1 add cli

.github/workflows/tests.yml

@@ -2,9 +2,7 @@ name: Tests
 
 on:
   push:
-    branches: [ "main" ]
   pull_request:
-    branches: [ "main" ]
 
 jobs:
   build:

pyproject.toml

@@ -30,8 +30,8 @@ requires-python = ">=3.9"
 repository = "https://github.com/wfatherley/hkdfref.git"
 
 
-# [project.scripts]
-# hkdf = hkdfref:cli
+[project.scripts]
+hkdf = "hkdfref:cli"
 
 
 [tool.setuptools.packages.find]

src/hkdfref/__init__.py

@@ -1,9 +1,97 @@
 """hkdfref"""
 import argparse
+import codecs
+import hashlib
 
-from ._hkdfref import expand, extract, hkdf, logger
+from sys import stdout
 
+from ._hkdfref import (
+    default_hash, default_salt, expand, extract, hkdf, logger
+)
 
-def cli():
-    """command line interface"""
-    pass
+
+def cli() -> None:
+    """return None"""
+    logger.debug("cli: enter")
+
+    # configure argument parser
+    argument_parser = argparse.ArgumentParser(
+        prog="hkdf",
+        description="Generate secure keying material according to RFC 5869.",
+        epilog="Specification: https://datatracker.ietf.org/doc/html/rfc5869",
+    )
+    argument_parser.add_argument(
+        "ikm",
+        type=lambda string: string.encode("latin-1"),
+        action="append",
+        help="Input key material. Fed into HKDF as UTF-8 bytes."
+    )
+    argument_parser.add_argument(
+        "-s",
+        "--salt",
+        type=lambda string: string.encode("latin-1"),
+        default=default_salt,
+        help=(
+            "Salt for extract step. Defaults to 0x00 * 20. Fed into HKDF as"
+            " UTF-8 bytes."
+        )
+    )
+    argument_parser.add_argument(
+        "--hash",
+        help="One of the known SHAs. Used by both extract and expand"
+    )
+    argument_parser.add_argument(
+        "--exthash",
+        help="One of the known SHAs. Used only by extract."
+    )
+    argument_parser.add_argument(
+        "--exphash",
+        help="One of the known SHAs. Used only by expand."
+    )
+    argument_parser.add_argument(
+        "-i",
+        "--info",
+        default=b"",
+        type=lambda string: string.encode("latin-1"),
+        help="Info for expand step. Fed into HKDF as UTF-8 bytes."
+    )
+    output_length_group = argument_parser.add_mutually_exclusive_group(required=True)
+    output_length_group.add_argument(
+        "-l",
+        "--length",
+        type=int,
+        help="First octets to return. Return whole without."
+    )
+    output_length_group.add_argument(
+        "--returnall", action="store_true", help="Return entire result"
+    )
+    argument_parser.add_argument(
+        "--skipextract", action="store_true", help="Skip extract step"
+    )
+
+    # parse arguments
+    namespace = argument_parser.parse_args()
+    logger.debug("cli: args=%s", namespace)
+
+    # rebind hash functions
+    namespace.hash = namespace.hash or default_hash
+    namespace.exthash = getattr(hashlib, str(namespace.exthash), default_hash)
+    namespace.exphash = getattr(hashlib, str(namespace.exphash), default_hash)
+
+    # return okm
+    stdout.write(
+        codecs.encode(
+            hkdf(
+                *namespace.ikm,
+                salt=namespace.salt,
+                l=namespace.length,
+                info=namespace.info,
+                extract_hash=namespace.exthash,
+                expand_hash=namespace.exphash,
+                hash=namespace.hash,
+                skip_extract=namespace.skipextract,
+                return_all=namespace.returnall
+            ),
+            "hex_codec"
+        ).decode()
+    )

src/hkdfref/_hkdfref.py

@@ -7,7 +7,7 @@
 from typing import Any, Callable
 
 
-logger = getLogger(__name__)
+logger = getLogger(__name__[1:])
 
 
 default_hash = hashlib.sha512
@@ -39,7 +39,9 @@ def hkdf(*ikm: bytes, **kwargs: Any) -> bytes:
         prk = extract(salt, *ikm, hash=extract_hash)
     else:
         prk = b"".join(ikm)
-    return expand(prk, info, l, expand_hash)
+    return expand(
+        prk, info, l, expand_hash, return_all=kwargs.get("return_all", False)
+    )
 
 
 def expand(