Add typing in signer.py (#1340)

Signed-off-by: Bala.FA <bala@minio.io>

minio/signer.py

@@ -26,32 +26,42 @@
 
 """
 
+from __future__ import absolute_import, annotations
+
 import hashlib
 import hmac
 import re
 from collections import OrderedDict
+from datetime import datetime
 from urllib.parse import SplitResult
 
 from . import time
+from .credentials import Credentials
 from .helpers import queryencode, sha256_hash
 
 SIGN_V4_ALGORITHM = 'AWS4-HMAC-SHA256'
 _MULTI_SPACE_REGEX = re.compile(r"( +)")
 
 
-def _hmac_hash(key, data, hexdigest=False):
+def _hmac_hash(
+        key: bytes | bytearray,
+        data: bytes,
+        hexdigest: bool = False,
+) -> bytes | str:
     """Return HMacSHA256 digest of given key and data."""
 
     hasher = hmac.new(key, data, hashlib.sha256)
     return hasher.hexdigest() if hexdigest else hasher.digest()
 
 
-def _get_scope(date, region, service_name):
+def _get_scope(date: datetime, region: str, service_name: str) -> str:
     """Get scope string."""
     return f"{time.to_signer_date(date)}/{region}/{service_name}/aws4_request"
 
 
-def _get_canonical_headers(headers):
+def _get_canonical_headers(
+        headers: dict[str, str | list[str] | tuple[str]],
+) -> tuple[dict[str, str], str]:
     """Get canonical headers."""
 
     canonical_headers = {}
@@ -74,7 +84,7 @@ def _get_canonical_headers(headers):
     return canonical_headers, signed_headers
 
 
-def _get_canonical_query_string(query):
+def _get_canonical_query_string(query: str) -> str:
     """Get canonical query string."""
 
     query = query or ""
@@ -87,7 +97,12 @@ def _get_canonical_query_string(query):
     )
 
 
-def _get_canonical_request_hash(method, url, headers, content_sha256):
+def _get_canonical_request_hash(
+        method: str,
+        url: SplitResult,
+        headers: dict[str, str | list[str] | tuple[str]],
+        content_sha256: str,
+) -> tuple[str, str]:
     """Get canonical request hash."""
     canonical_headers, signed_headers = _get_canonical_headers(headers)
     canonical_query_string = _get_canonical_query_string(url.query)
@@ -110,35 +125,64 @@ def _get_canonical_request_hash(method, url, headers, content_sha256):
     return sha256_hash(canonical_request), signed_headers
 
 
-def _get_string_to_sign(date, scope, canonical_request_hash):
+def _get_string_to_sign(
+        date: datetime,
+        scope: str,
+        canonical_request_hash: str,
+) -> str:
     """Get string-to-sign."""
     return (
         f"AWS4-HMAC-SHA256\n{time.to_amz_date(date)}\n{scope}\n"
         f"{canonical_request_hash}"
     )
 
 
-def _get_signing_key(secret_key, date, region, service_name):
+def _get_signing_key(
+        secret_key: str,
+        date: datetime,
+        region: str,
+        service_name: str,
+) -> bytes:
     """Get signing key."""
 
     date_key = _hmac_hash(
         ("AWS4" + secret_key).encode(),
         time.to_signer_date(date).encode(),
     )
+    if isinstance(date_key, str):
+        date_key = date_key.encode()
+
     date_region_key = _hmac_hash(date_key, region.encode())
+    if isinstance(date_region_key, str):
+        date_region_key = date_region_key.encode()
+
     date_region_service_key = _hmac_hash(
         date_region_key, service_name.encode(),
     )
-    return _hmac_hash(date_region_service_key, b"aws4_request")
+    if isinstance(date_region_service_key, str):
+        date_region_service_key = date_region_service_key.encode()
+
+    signing_key = _hmac_hash(date_region_service_key, b"aws4_request")
+    if isinstance(signing_key, str):
+        signing_key = signing_key.encode()
 
+    return signing_key
 
-def _get_signature(signing_key, string_to_sign):
+
+def _get_signature(signing_key: bytes, string_to_sign: str) -> str:
     """Get signature."""
 
-    return _hmac_hash(signing_key, string_to_sign.encode(), hexdigest=True)
+    return str(
+        _hmac_hash(signing_key, string_to_sign.encode(), hexdigest=True),
+    )
 
 
-def _get_authorization(access_key, scope, signed_headers, signature):
+def _get_authorization(
+        access_key: str,
+        scope: str,
+        signed_headers: str,
+        signature: str,
+) -> str:
     """Get authorization."""
     return (
         f"AWS4-HMAC-SHA256 Credential={access_key}/{scope}, "
@@ -147,15 +191,15 @@ def _get_authorization(access_key, scope, signed_headers, signature):
 
 
 def _sign_v4(
-        service_name,
-        method,
-        url,
-        region,
-        headers,
-        credentials,
-        content_sha256,
-        date,
-):
+        service_name: str,
+        method: str,
+        url: SplitResult,
+        region: str,
+        headers: dict[str, str | list[str] | tuple[str]],
+        credentials: Credentials,
+        content_sha256: str,
+        date: datetime,
+) -> dict[str, str | list[str] | tuple[str]]:
     """Do signature V4 of given request for given service name."""
 
     scope = _get_scope(date, region, service_name)
@@ -175,14 +219,14 @@ def _sign_v4(
 
 
 def sign_v4_s3(
-        method,
-        url,
-        region,
-        headers,
-        credentials,
-        content_sha256,
-        date,
-):
+        method: str,
+        url: SplitResult,
+        region: str,
+        headers: dict[str, str | list[str] | tuple[str]],
+        credentials: Credentials,
+        content_sha256: str,
+        date: datetime,
+) -> dict[str, str | list[str] | tuple[str]]:
     """Do signature V4 of given request for S3 service."""
     return _sign_v4(
         "s3",
@@ -197,14 +241,14 @@ def sign_v4_s3(
 
 
 def sign_v4_sts(
-        method,
-        url,
-        region,
-        headers,
-        credentials,
-        content_sha256,
-        date,
-):
+        method: str,
+        url: SplitResult,
+        region: str,
+        headers: dict[str, str | list[str] | tuple[str]],
+        credentials: Credentials,
+        content_sha256: str,
+        date: datetime,
+) -> dict[str, str | list[str] | tuple[str]]:
     """Do signature V4 of given request for STS service."""
     return _sign_v4(
         "sts",
@@ -219,8 +263,13 @@ def sign_v4_sts(
 
 
 def _get_presign_canonical_request_hash(  # pylint: disable=invalid-name
-        method, url, access_key, scope, date, expires,
-):
+        method: str,
+        url: SplitResult,
+        access_key: str,
+        scope: str,
+        date: datetime,
+        expires: int,
+) -> tuple[str, SplitResult]:
     """Get canonical request hash for presign request."""
     x_amz_credential = queryencode(access_key + "/" + scope)
     canonical_headers, signed_headers = "host:" + url.netloc, "host"