feat: added create_hmac_signature function

Author: danpoletaev

src/apify/_crypto.py

@@ -1,6 +1,8 @@
 from __future__ import annotations
 
 import base64
+import hashlib
+import hmac
 from typing import Any
 
 from cryptography.exceptions import InvalidTag as InvalidTagException
@@ -153,3 +155,37 @@ def decrypt_input_secrets(private_key: rsa.RSAPrivateKey, input_data: Any) -> An
                 )
 
     return input_data
+
+
+CHARSET = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'
+
+
+def encode_base62(num: int) -> str:
+    """Encode the given number to base62."""
+    if num == 0:
+        return CHARSET[0]
+
+    res = ''
+    while num > 0:
+        num, remainder = divmod(num, 62)
+        res = CHARSET[remainder] + res
+    return res
+
+
+# createHmacSignature
+@ignore_docs
+def create_hmac_signature(secret_key: str, message: str) -> str:
+    """Generates an HMAC signature and encodes it using Base62. Base62 encoding reduces the signature length.
+
+    Args:
+        secret_key (str): Secret key used for signing signatures
+        message (str): Message to be signed
+
+    Returns:
+        str: Base62 encoded signature
+    """
+    signature = hmac.new(secret_key.encode('utf-8'), message.encode('utf-8'), hashlib.sha256).hexdigest()[:30]
+
+    decimal_signature = int(signature, 16)
+
+    return encode_base62(decimal_signature)

tests/unit/test_crypto.py

@@ -4,7 +4,14 @@
 
 import pytest
 
-from apify._crypto import _load_public_key, crypto_random_object_id, load_private_key, private_decrypt, public_encrypt
+from apify._crypto import (
+    _load_public_key,
+    create_hmac_signature,
+    crypto_random_object_id,
+    load_private_key,
+    private_decrypt,
+    public_encrypt,
+)
 
 # NOTE: Uses the same keys as in:
 # https://github.com/apify/apify-shared-js/blob/master/test/crypto.test.ts
@@ -105,3 +112,20 @@ def test_crypto_random_object_id_length_and_charset() -> None:
     long_random_object_id = crypto_random_object_id(1000)
     for char in long_random_object_id:
         assert char in 'abcdefghijklmnopqrstuvwxyzABCEDFGHIJKLMNOPQRSTUVWXYZ0123456789'
+
+
+# Check if the method is compatible with js version of the same method in:
+# https://github.com/apify/apify-shared-js/blob/master/packages/utilities/src/hmac.ts
+def test_create_valid_hmac_signature() -> None:
+    # This test uses the same secret key and message as in JS tests.
+    secret_key = 'hmac-secret-key'
+    message = 'hmac-message-to-be-authenticated'
+    assert create_hmac_signature(secret_key, message) == 'pcVagAsudj8dFqdlg7mG'
+
+
+def test_create_same_hmac() -> None:
+    # This test uses the same secret key and message as in JS tests.
+    secret_key = 'hmac-same-secret-key'
+    message = 'hmac-same-message-to-be-authenticated'
+    for _ in range(5):
+        assert create_hmac_signature(secret_key, message) == 'FYMcmTIm3idXqleF1Sw5'