Initial Home Assistant commit

custom_components/spotcast/crypto.py

@@ -0,0 +1,33 @@
+"""Module for cryptographic methods and functions"""
+
+from base64 import b32encode
+
+from pyotp import TOTP
+
+
+_CIPHER_BASE = (12, 56, 76, 33, 88, 44, 88, 33,
+                78, 78, 11, 66, 22, 22, 55, 69, 54)
+CIPHER_BYTES = [j ^ (i % 33 + 9) for i, j in enumerate(_CIPHER_BASE)]
+
+
+def hex_to_bytes(data: str) -> bytes:
+    """Converts a hex string to bytes"""
+    data = data.replace(" ", "")
+    return bytes.fromhex(data)
+
+
+def get_totp(
+        digits: int = 6,
+        digest: str = "sha1",
+        interval: int = 30
+) -> TOTP:
+    """Provides a time-based OTP manager compliant for spotify TOTP
+    scheme"""
+
+    secret_hex = ''.join(str(x) for x in CIPHER_BYTES)
+    secret_hex = secret_hex.encode()
+    secret_hex = "".join(format(x, 'x') for x in secret_hex)
+    secret_bytes = hex_to_bytes(secret_hex)
+    secret = b32encode(secret_bytes).decode().strip('=')
+
+    return TOTP(secret, digits=digits, digest=digest, interval=interval)