lnonion/onion_wire: encrypted_data -> encrypted_recipient_data

diff --git a/electrum/lnonion.py b/electrum/lnonion.py
index a334fee..0770025 100644
--- a/electrum/lnonion.py
+++ b/electrum/lnonion.py
@@ -288,29 +288,16 @@ def decrypt_onionmsg_data_tlv(*, shared_secret: bytes, encrypted_recipient_data:
 
 
 def encrypt_hops_recipient_data(
-        tlv_stream_name: str,
         hops_data: List[OnionHopsDataSingle],
         hop_shared_secrets: Sequence[bytes]
 ) -> None:
-    """encrypt unencrypted encrypted_recipient_data for hops with blind_fields.
-
-       NOTE: contents of payload.encrypted_recipient_data is slightly different for 'payload'
-       vs 'oniomsg_tlv' tlv_stream_names, so we map to the correct key here based on tlv_stream_name.
-       We can also change onion_wire.csv to use the same key, but as we import that from specs it might
-       regress in the future, so I rather make it explicit in code here.
-    """
-    # key naming payload TLV vs onionmsg_tlv TLV
-    erd_key = 'encrypted_recipient_data' if tlv_stream_name == 'onionmsg_tlv' else 'encrypted_data'
-
-    num_hops = len(hops_data)
-    for i in range(num_hops):
-        if hops_data[i].tlv_stream_name == tlv_stream_name and 'encrypted_recipient_data' not in hops_data[i].payload:
-            # construct encrypted_recipient_data from blind_fields
-            encrypted_recipient_data = encrypt_onionmsg_data_tlv(shared_secret=hop_shared_secrets[i], **hops_data[i].blind_fields)
-            # work around immutablility of OnionHopsDataSingle
-            hop_payload = {'encrypted_recipient_data': {erd_key: encrypted_recipient_data}}
-            hop_payload.update(hops_data[i].payload)
-            hops_data[i] = OnionHopsDataSingle(tlv_stream_name=hops_data[i].tlv_stream_name, payload=hop_payload, blind_fields=hops_data[i].blind_fields)
+    """Encrypt plaintext OnionHopsDataSingle.blind_fields into encrypted_recipient_data"""
+    for i, (hop_data, hop_shared_secret) in enumerate(zip(hops_data, hop_shared_secrets)):
+        assert 'encrypted_recipient_data' not in hop_data.payload, hop_data
+        encrypted_recipient_data = encrypt_onionmsg_data_tlv(shared_secret=hop_shared_secret, **hop_data.blind_fields)
+        new_hop_payload = {'encrypted_recipient_data': {'encrypted_recipient_data': encrypted_recipient_data}}
+        new_hop_payload.update(hop_data.payload)  # keep other fields
+        hops_data[i] = replace(hop_data, payload=new_hop_payload)
 
 
 def calc_hops_data_for_payment(
diff --git a/electrum/lnwire/onion_wire.csv b/electrum/lnwire/onion_wire.csv
index 06b55da..1353120 100644
--- a/electrum/lnwire/onion_wire.csv
+++ b/electrum/lnwire/onion_wire.csv
@@ -8,9 +8,9 @@ tlvtype,payload,payment_data,8
 tlvdata,payload,payment_data,payment_secret,byte,32
 tlvdata,payload,payment_data,total_msat,tu64,
 tlvtype,payload,encrypted_recipient_data,10
-tlvdata,payload,encrypted_recipient_data,encrypted_data,byte,...
-tlvtype,payload,current_blinding_point,12
-tlvdata,payload,current_blinding_point,blinding,point,
+tlvdata,payload,encrypted_recipient_data,encrypted_recipient_data,byte,...
+tlvtype,payload,current_path_key,12
+tlvdata,payload,current_path_key,path_key,point,
 tlvtype,payload,payment_metadata,16
 tlvdata,payload,payment_metadata,payment_metadata,byte,...
 tlvtype,payload,total_amount_msat,18
diff --git a/electrum/onion_message.py b/electrum/onion_message.py
index a98775e..1c851c1 100644
--- a/electrum/onion_message.py
+++ b/electrum/onion_message.py
@@ -237,7 +237,7 @@ def create_route_to_introduction_point(
     )
     hops_data.append(final_hop_pre_ip)
 
-    encrypt_hops_recipient_data(tlv_stream_name='onionmsg_tlv', hops_data=hops_data, hop_shared_secrets=hop_shared_secrets)
+    encrypt_hops_recipient_data(hops_data=hops_data, hop_shared_secrets=hop_shared_secrets)
     path_key = ecc.ECPrivkey(session_key).get_public_key_bytes()
 
     return peer, path_key, hops_data, blinded_node_ids
@@ -366,7 +366,7 @@ def send_onion_message_to(
         payment_path_pubkeys = [edge.end_node for edge in path]
 
         hop_shared_secrets, blinded_node_ids = get_shared_secrets_along_route(payment_path_pubkeys, session_key)
-        encrypt_hops_recipient_data('onionmsg_tlv', hops_data, hop_shared_secrets)
+        encrypt_hops_recipient_data(hops_data, hop_shared_secrets)
         packet = new_onion_packet(blinded_node_ids, session_key, hops_data)
         packet_b = packet.to_bytes()
 
diff --git a/tests/test_onion_message.py b/tests/test_onion_message.py
index 63e5803..aebd372 100644
--- a/tests/test_onion_message.py
+++ b/tests/test_onion_message.py
@@ -106,7 +106,7 @@ class TestOnionMessage(ElectrumTestCase):
             )
         ]
 
-        encrypt_hops_recipient_data('onionmsg_tlv', hops_data, hop_shared_secrets)
+        encrypt_hops_recipient_data(hops_data, hop_shared_secrets)
         packet = new_onion_packet(blinded_node_ids, SESSION_KEY, hops_data, onion_message=True)
         self.assertEqual(packet.to_bytes(), ONION_MESSAGE_PACKET)
 
@@ -128,18 +128,18 @@ class TestOnionMessage(ElectrumTestCase):
                 ),
             ]
         hops_data = hops_data_for_message('short_message')  # fit in HOPS_DATA_SIZE
-        encrypt_hops_recipient_data('onionmsg_tlv', hops_data, hop_shared_secrets)
+        encrypt_hops_recipient_data(hops_data, hop_shared_secrets)
         packet = new_onion_packet(blinded_node_ids, SESSION_KEY, hops_data, onion_message=True)
         self.assertEqual(len(packet.to_bytes()), HOPS_DATA_SIZE + 66)
 
         hops_data = hops_data_for_message('A' * HOPS_DATA_SIZE)  # fit in ONION_MESSAGE_LARGE_SIZE
-        encrypt_hops_recipient_data('onionmsg_tlv', hops_data, hop_shared_secrets)
+        encrypt_hops_recipient_data(hops_data, hop_shared_secrets)
         packet = new_onion_packet(blinded_node_ids, SESSION_KEY, hops_data, onion_message=True)
 
         self.assertEqual(len(packet.to_bytes()), ONION_MESSAGE_LARGE_SIZE + 66)
 
         hops_data = hops_data_for_message('A' * ONION_MESSAGE_LARGE_SIZE)  # does not fit in ONION_MESSAGE_LARGE_SIZE
-        encrypt_hops_recipient_data('onionmsg_tlv', hops_data, hop_shared_secrets)
+        encrypt_hops_recipient_data(hops_data, hop_shared_secrets)
 
         with self.assertRaises(InvalidPayloadSize):
             new_onion_packet(blinded_node_ids, SESSION_KEY, hops_data, onion_message=True)
@@ -244,11 +244,7 @@ class TestOnionMessage(ElectrumTestCase):
             ),
         ]
         # encrypt encrypted_data_tlv here
-        for i in range(len(hops_data)):
-            encrypted_recipient_data = encrypt_onionmsg_data_tlv(shared_secret=hop_shared_secrets[i], **hops_data[i].blind_fields)
-            new_payload = dict(hops_data[i].payload)
-            new_payload['encrypted_recipient_data'] = {'encrypted_recipient_data': encrypted_recipient_data}
-            hops_data[i] = dataclasses.replace(hops_data[i], payload=new_payload)
+        encrypt_hops_recipient_data(hops_data, hop_shared_secrets)
 
         blinded_path_blinded_ids = []
         for i, x in enumerate(blinded_path_to_dave.get('path')):
@@ -263,8 +259,6 @@ class TestOnionMessage(ElectrumTestCase):
                     payload=payload),
             )
         payment_path_pubkeys = blinded_node_ids + blinded_path_blinded_ids
-        hop_shared_secrets, _ = get_shared_secrets_along_route(payment_path_pubkeys, SESSION_KEY)
-        encrypt_hops_recipient_data('onionmsg_tlv', hops_data, hop_shared_secrets)
         packet = new_onion_packet(payment_path_pubkeys, SESSION_KEY, hops_data, onion_message=True)
         self.assertEqual(packet.to_bytes(), ONION_MESSAGE_PACKET)