Add support for Arizona Public Service (#95)

* Add support for Arizona Public Service

* Moved cryptography dependency to non-optional dependencies and updated variable to lowercase

* Updated js_encrypt command to verify the key is an RSA key

README.md

@@ -12,6 +12,7 @@ Supported utilities (in alphabetical order):
   - Kentucky Power
   - Public Service Company of Oklahoma (PSO)
   - Southwestern Electric Power Company (SWEPCO)
+- Arizona Public Service (APS)
 - City of Austin Utilities
 - Consolidated Edison (ConEd)
   - Orange & Rockland Utilities (ORU)

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "opower"
-version = "0.7.0"
+version = "0.8.0"
 license = {text = "Apache-2.0"}
 authors = [
     { name="tronikos", email="tronikos@gmail.com" },
@@ -12,6 +12,7 @@ dependencies = [
     "aiohttp>=3.8",
     "aiozoneinfo>=0.1",
     "arrow>=1.2",
+    "cryptography>=43.0.0",
     "pyotp>=2.0",
 ]
 

src/opower/utilities/aps.py

@@ -0,0 +1,120 @@
+"""Arizona Public Service (APS)."""
+
+import logging
+import re
+from typing import Optional
+
+import aiohttp
+
+from ..const import USER_AGENT
+from ..exceptions import CannotConnect, InvalidAuth
+from .base import UtilityBase
+from .helpers import async_auth_saml, js_encrypt
+
+_LOGGER = logging.getLogger(__name__)
+
+
+class Aps(UtilityBase):
+    """Arizona Public Service (APS)."""
+
+    @staticmethod
+    def name() -> str:
+        """Distinct recognizable name of the utility."""
+        return "Arizona Public Service (APS)"
+
+    @staticmethod
+    def subdomain() -> str:
+        """Return the opower.com subdomain for this utility."""
+        return "aps"
+
+    @staticmethod
+    def timezone() -> str:
+        """Return the timezone."""
+        return "America/Phoenix"
+
+    @staticmethod
+    async def async_login(
+        session: aiohttp.ClientSession,
+        username: str,
+        password: str,
+        optional_mfa_secret: Optional[str],
+    ) -> None:
+        """Login to the utility website."""
+        _LOGGER.debug("Starting login process for Arizona Public Service (APS)")
+        session.cookie_jar.clear(lambda cookie: cookie["domain"] == "www.aps.com")
+
+        # Get public RSA key APS uses to encrypt the password
+        async with session.get(
+            "https://www.aps.com/Assets/Js/aps-apscom.js",
+            headers={"User-Agent": USER_AGENT},
+            raise_for_status=True,
+        ) as resp:
+            html = await resp.text()
+        rsa_key_text = extract_rsa_key(html)
+
+        # Encrypt the password
+        encrypted_password = js_encrypt(rsa_key_text, password)
+
+        data = {
+            "username": username,
+            "password": encrypted_password,
+        }
+
+        # Send the POST request
+        async with session.post(
+            "https://www.aps.com/api/sitecore/SitecoreReactApi/UserAuthentication",
+            json=data,
+            raise_for_status=True,
+        ) as resp:
+            login_result = await resp.json(content_type="text/html")
+            if login_result["isLoginSuccess"] is False:
+                raise InvalidAuth("Username and password failed")
+
+        # Get All User Details to get APS Account ID and Service Address ID
+        async with session.get(
+            "https://www.aps.com/api/sitecore/sitecorereactapi/GetAllUserDetails",
+            raise_for_status=True,
+        ) as resp:
+            user_details = await resp.json(content_type="application /json")
+            account_id = user_details["Details"]["AccountDetails"][
+                "getAccountDetailsResponse"
+            ]["getAccountDetailsRes"]["getPersonDetails"]["accountID"]
+
+            service_address_id = user_details["Details"]["AccountDetails"][
+                "getAccountDetailsResponse"
+            ]["getAccountDetailsRes"]["getSASPListByAccountID"]["premiseDetailsList"][
+                0
+            ][
+                "sASPDetails"
+            ][
+                0
+            ][
+                "sAID"
+            ]
+
+        account_service_id = f"{account_id}_{service_address_id}"
+
+        # Start SAML authentication with APS and Opower
+        url = f"https://www.aps.com/en/Residential/Save-Money-and-Energy/Opower?CA_SA={account_service_id}"
+        await async_auth_saml(session, url)
+
+
+def extract_rsa_key(js_content: str) -> str:
+    """Extract the RSA public key from the APS JS file, using the identifier 'APSCOMWebPasswordpublicKey'."""
+    pattern = r'APSCOMWebPasswordpublicKey:"(-----BEGIN PUBLIC KEY-----.*?-----END PUBLIC KEY-----)"'
+
+    # Find the RSA key associated with the regex pattern above
+    match = re.search(pattern, js_content, re.DOTALL)
+
+    if match:
+        # Get and format the RSA key
+        rsa_key = match.group(1)
+        formatted_key = re.sub(
+            r"(-----BEGIN PUBLIC KEY-----)(.*)(-----END PUBLIC KEY-----)",
+            r"\1\n\2\n\3",
+            rsa_key,
+            flags=re.DOTALL,
+        )
+        return formatted_key
+    else:
+        raise CannotConnect("The RSA public key was not found.")

src/opower/utilities/helpers.py

@@ -1,8 +1,11 @@
 """Helper functions."""
 
+import base64
 import re
 
 import aiohttp
+from cryptography.hazmat.primitives import serialization
+from cryptography.hazmat.primitives.asymmetric import padding, rsa
 
 from ..const import USER_AGENT
 
@@ -55,3 +58,20 @@ async def async_auth_saml(session: aiohttp.ClientSession, url: str) -> None:
         raise_for_status=True,
     ) as resp:
         pass
+
+
+def js_encrypt(pub_key: str, text: str) -> str:
+    """JSEncrypt-like encryption function using cryptography."""
+    # Load the public key
+    rsakey = serialization.load_pem_public_key(pub_key.encode())
+    # Check if the key is RSA before encrypting
+    if isinstance(rsakey, rsa.RSAPublicKey):
+        # Encrypt the text using RSA and PKCS1v15 padding
+        cipher_text = rsakey.encrypt(text.encode(), padding.PKCS1v15())
+
+        # Encode the encrypted text in base64
+        cipher_text_base64 = base64.b64encode(cipher_text)
+
+        return cipher_text_base64.decode()
+    else:
+        raise ConnectionError("Could not find public key to and encrypt password.")