[feat] Add stripe payments (#3184)

lnbits/core/services/fiat_providers.py

@@ -0,0 +1,92 @@
+import hashlib
+import hmac
+import time
+from typing import Optional
+
+from loguru import logger
+
+from lnbits.core.crud.payments import get_standalone_payment
+from lnbits.core.models.misc import SimpleStatus
+from lnbits.fiat import get_fiat_provider
+
+
+async def handle_stripe_event(event: dict):
+    event_id = event.get("id")
+    event_object = event.get("data", {}).get("object", {})
+    object_type = event_object.get("object")
+    payment_hash = event_object.get("metadata", {}).get("payment_hash")
+    logger.debug(
+        f"Handling Stripe event: '{event_id}'. Type: '{object_type}'."
+        f" Payment hash: '{payment_hash}'."
+    )
+    if not payment_hash:
+        logger.warning("Stripe event does not contain a payment hash.")
+        return
+
+    payment = await get_standalone_payment(payment_hash)
+    if not payment:
+        logger.warning(f"No payment found for hash: '{payment_hash}'.")
+        return
+    await payment.check_fiat_status()
+
+
+def check_stripe_signature(
+    payload: bytes,
+    sig_header: Optional[str],
+    secret: Optional[str],
+    tolerance_seconds=300,
+):
+    if not sig_header:
+        logger.warning("Stripe-Signature header is missing.")
+        raise ValueError("Stripe-Signature header is missing.")
+
+    if not secret:
+        logger.warning("Stripe webhook signing secret is not set.")
+        raise ValueError("Stripe webhook cannot be verified.")
+
+    # Split the Stripe-Signature header
+    items = dict(i.split("=") for i in sig_header.split(","))
+    timestamp = int(items["t"])
+    signature = items["v1"]
+
+    # Check timestamp tolerance
+    if abs(time.time() - timestamp) > tolerance_seconds:
+        logger.warning("Timestamp outside tolerance.")
+        logger.debug(
+            f"Current time: {time.time()}, "
+            f"Timestamp: {timestamp}, "
+            f"Tolerance: {tolerance_seconds} seconds"
+        )
+
+        raise ValueError("Timestamp outside tolerance." f"Timestamp: {timestamp}")
+
+    signed_payload = f"{timestamp}.{payload.decode()}"
+
+    # Compute HMAC SHA256 using the webhook secret
+    computed_signature = hmac.new(
+        key=secret.encode(), msg=signed_payload.encode(), digestmod=hashlib.sha256
+    ).hexdigest()
+
+    # Compare signatures using constant time comparison
+    if hmac.compare_digest(computed_signature, signature) is not True:
+        logger.warning("Stripe signature verification failed.")
+        raise ValueError("Stripe signature verification failed.")
+
+
+async def test_connection(provider: str) -> SimpleStatus:
+    """
+    Test the connection to Stripe by checking if the API key is valid.
+    This function should be called when setting up or testing the Stripe integration.
+    """
+    fiat_provider = await get_fiat_provider(provider)
+    status = await fiat_provider.status()
+    if status.error_message:
+        return SimpleStatus(
+            success=False,
+            message=f"Cconnection test failed: {status.error_message}",
+        )
+
+    return SimpleStatus(
+        success=True,
+        message="Connection test successful." f" Balance: {status.balance}.",
+    )