'invoice' command returning preimage.

doc/lightning-listinvoices.7.md

@@ -15,17 +15,16 @@ if it exists, or the status of all invoices if given no argument.
 RETURN VALUE
 ------------
 
-On success, an array *invoices* of objects is returned. Each object
-contains *label*, *payment\_hash*, *status* (one of *unpaid*, *paid* or
-*expired*), and *expiry\_time* (a UNIX timestamp). If the *msatoshi*
-argument to lightning-invoice(7) was not "any", there will be an
-*msatoshi* field as a number, and *amount\_msat* as the same number
-ending in *msat*. If the invoice *status* is *paid*, there will be a
-*pay\_index* field and an *msatoshi\_received* field (which may be
-slightly greater than *msatoshi* as some overpaying is permitted to
-allow clients to obscure payment paths); there will also be an
-*amount\_received\_msat* field with the same number as
-*msatoshi\_received* but ending in *msat*.
+On success, an array *invoices* of objects is returned. Each object contains
+*label*, *payment\_hash*, *status* (one of *unpaid*, *paid* or *expired*),
+*payment\_preimage* (for paid invoices), and *expiry\_time* (a UNIX
+timestamp).  If the *msatoshi* argument to lightning-invoice(7) was not "any",
+there will be an *msatoshi* field as a number, and *amount\_msat* as the same
+number ending in *msat*. If the invoice *status* is *paid*, there will be a
+*pay\_index* field and an *msatoshi\_received* field (which may be slightly
+greater than *msatoshi* as some overpaying is permitted to allow clients to
+obscure payment paths); there will also be an *amount\_received\_msat* field
+with the same number as *msatoshi\_received* but ending in *msat*.
 
 AUTHOR
 ------

lightningd/invoice.c

@@ -61,6 +61,7 @@ static void json_add_invoice(struct json_stream *response,
 					    "msatoshi_received",
 					    "amount_received_msat");
 		json_add_u64(response, "paid_at", inv->paid_timestamp);
+		json_add_preimage(response, "payment_preimage", &inv->r);
 	}
 	if (inv->description)
 		json_add_string(response, "description", inv->description);
@@ -138,8 +139,7 @@ invoice_payment_serialize(struct invoice_payment_hook_payload *payload,
 {
 	json_object_start(stream, "payment");
 	json_add_escaped_string(stream, "label", payload->label);
-	json_add_hex(stream, "preimage",
-		     &payload->preimage, sizeof(payload->preimage));
+	json_add_preimage(stream, "preimage", &payload->preimage);
 	json_add_string(stream, "msat",
 			type_to_string(tmpctx, struct amount_msat,
 				       &payload->msat));

lightningd/json.c

@@ -438,6 +438,12 @@ void json_add_sha256(struct json_stream *result, const char *fieldname,
 	json_add_hex(result, fieldname, hash, sizeof(*hash));
 }
 
+void json_add_preimage(struct json_stream *result, const char *fieldname,
+		     const struct preimage *preimage)
+{
+	json_add_hex(result, fieldname, preimage, sizeof(*preimage));
+}
+
 /**
  * segwit_addr_net_decode - Try to decode a Bech32 address and detect
  * testnet/mainnet/regtest/signet

lightningd/json.h

@@ -27,6 +27,7 @@ struct json_stream;
 struct pubkey;
 struct node_id;
 struct sha256;
+struct preimage;
 struct short_channel_id;
 struct wallet_payment;
 struct wallet_tx;
@@ -206,6 +207,9 @@ void json_add_time(struct json_stream *result, const char *fieldname,
 void json_add_sha256(struct json_stream *result, const char *fieldname,
 		     const struct sha256 *hash);
 
+void json_add_preimage(struct json_stream *result, const char *fieldname,
+		     const struct preimage *preimage);
+
 struct command_result *param_bitcoin_address(struct command *cmd,
 					     const char *name,
 					     const char *buffer,

lightningd/pay.c

@@ -108,9 +108,8 @@ void json_add_payment_fields(struct json_stream *response,
 		break;
 	}
 	if (t->payment_preimage)
-		json_add_hex(response, "payment_preimage",
-			     t->payment_preimage,
-			     sizeof(*t->payment_preimage));
+		json_add_preimage(response, "payment_preimage",
+                    t->payment_preimage);
 	if (t->label)
 		json_add_string(response, "label", t->label);
 	if (t->bolt11)

lightningd/test/run-invoice-select-inchan.c

@@ -170,10 +170,6 @@ void json_add_escaped_string(struct json_stream *result UNNEEDED,
 			     const char *fieldname UNNEEDED,
 			     const struct json_escape *esc TAKES UNNEEDED)
 { fprintf(stderr, "json_add_escaped_string called!\n"); abort(); }
-/* Generated stub for json_add_hex */
-void json_add_hex(struct json_stream *result UNNEEDED, const char *fieldname UNNEEDED,
-		  const void *data UNNEEDED, size_t len UNNEEDED)
-{ fprintf(stderr, "json_add_hex called!\n"); abort(); }
 /* Generated stub for json_add_hex_talarr */
 void json_add_hex_talarr(struct json_stream *result UNNEEDED,
 			 const char *fieldname UNNEEDED,
@@ -194,6 +190,10 @@ void json_add_node_id(struct json_stream *response UNNEEDED,
 void json_add_num(struct json_stream *result UNNEEDED, const char *fieldname UNNEEDED,
 		  unsigned int value UNNEEDED)
 { fprintf(stderr, "json_add_num called!\n"); abort(); }
+/* Generated stub for json_add_preimage */
+void json_add_preimage(struct json_stream *result UNNEEDED, const char *fieldname UNNEEDED,
+		     const struct preimage *preimage UNNEEDED)
+{ fprintf(stderr, "json_add_preimage called!\n"); abort(); }
 /* Generated stub for json_add_secret */
 void json_add_secret(struct json_stream *response UNNEEDED,
 		     const char *fieldname UNNEEDED,

tests/test_pay.py

@@ -517,6 +517,7 @@ def only_one(arr):
     assert only_one(l2.rpc.listinvoices('testpayment2')['invoices'])['status'] == 'paid'
     assert only_one(l2.rpc.listinvoices('testpayment2')['invoices'])['pay_index'] == 1
     assert only_one(l2.rpc.listinvoices('testpayment2')['invoices'])['msatoshi_received'] == rs['msatoshi']
+    assert only_one(l2.rpc.listinvoices('testpayment2')['invoices'])['payment_preimage'] == preimage
 
     # Balances should reflect it.
     def check_balances():