From 917708450548c81bad537c07ee55f990087a6cb9 Mon Sep 17 00:00:00 2001
From: Rusty Russell <rusty@rustcorp.com.au>
Date: Fri, 21 Jul 2023 09:53:26 +0930
Subject: [PATCH] lightningd: new runes infrastructure.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
 lightningd/Makefile                   |  1 +
 lightningd/lightningd.c               |  6 ++++
 lightningd/lightningd.h               |  3 ++
 lightningd/runes.c                    | 43 +++++++++++++++++++++++++++
 lightningd/runes.h                    |  7 +++++
 lightningd/test/run-find_my_abspath.c |  3 ++
 6 files changed, 63 insertions(+)
 create mode 100644 lightningd/runes.c
 create mode 100644 lightningd/runes.h

diff --git a/lightningd/Makefile b/lightningd/Makefile
index 15bed238e..0085da531 100644
--- a/lightningd/Makefile
+++ b/lightningd/Makefile
@@ -37,6 +37,7 @@ LIGHTNINGD_SRC :=				\
 	lightningd/plugin_control.c		\
 	lightningd/plugin_hook.c		\
 	lightningd/routehint.c			\
+	lightningd/runes.c			\
 	lightningd/subd.c			\
 	lightningd/watch.c
 
diff --git a/lightningd/lightningd.c b/lightningd/lightningd.c
index f85cc94fe..c420337a5 100644
--- a/lightningd/lightningd.c
+++ b/lightningd/lightningd.c
@@ -71,6 +71,7 @@
 #include <lightningd/lightningd.h>
 #include <lightningd/onchain_control.h>
 #include <lightningd/plugin.h>
+#include <lightningd/runes.h>
 #include <lightningd/subd.h>
 #include <sys/resource.h>
 #include <wallet/txfilter.h>
@@ -1118,6 +1119,11 @@ int main(int argc, char *argv[])
 	else if (max_blockheight != UINT32_MAX)
 		max_blockheight -= ld->config.rescan;
 
+	/*~ We have bearer tokens called `runes` you can use to control access.  They have
+	 * a fascinating history which I shall not go into now, but they're derived from
+	 * Macaroons which was a over-engineered Googlism. */
+	ld->runes = runes_init(ld);
+
 	/*~ That's all of the wallet db operations for now. */
 	db_commit_transaction(ld->wallet->db);
 
diff --git a/lightningd/lightningd.h b/lightningd/lightningd.h
index 6f8ffd992..ac70e252a 100644
--- a/lightningd/lightningd.h
+++ b/lightningd/lightningd.h
@@ -371,6 +371,9 @@ struct lightningd {
 
 	/* For anchors: how much do we keep for spending close txs? */
 	struct amount_sat emergency_sat;
+
+	/* runes! */
+	struct runes *runes;
 };
 
 /* Turning this on allows a tal allocation to return NULL, rather than aborting.
diff --git a/lightningd/runes.c b/lightningd/runes.c
new file mode 100644
index 000000000..837398ba5
--- /dev/null
+++ b/lightningd/runes.c
@@ -0,0 +1,43 @@
+#include "config.h"
+#include <ccan/array_size/array_size.h>
+#include <ccan/rune/rune.h>
+#include <ccan/tal/str/str.h>
+#include <common/json_command.h>
+#include <common/json_param.h>
+#include <common/json_stream.h>
+#include <common/type_to_string.h>
+#include <db/exec.h>
+#include <hsmd/hsmd_wiregen.h>
+#include <lightningd/hsm_control.h>
+#include <lightningd/jsonrpc.h>
+#include <lightningd/lightningd.h>
+#include <lightningd/runes.h>
+#include <wallet/wallet.h>
+
+/* This is lightningd->runes */
+struct runes {
+	struct rune *master;
+	u64 next_unique_id;
+	struct rune_blacklist *blacklist;
+};
+
+struct runes *runes_init(struct lightningd *ld)
+{
+	const u8 *msg;
+	struct runes *runes = tal(ld, struct runes);
+	const u8 *data;
+	struct secret secret;
+
+	runes->next_unique_id = db_get_intvar(ld->wallet->db, "runes_uniqueid", 0);
+	runes->blacklist = wallet_get_runes_blacklist(runes, ld->wallet);
+
+	/* Runes came out of commando, hence the derivation key is 'commando' */
+	data = tal_dup_arr(tmpctx, u8, (u8 *)"commando", strlen("commando"), 0);
+	msg = hsm_sync_req(tmpctx, ld, towire_hsmd_derive_secret(tmpctx, data));
+	if (!fromwire_hsmd_derive_secret_reply(msg, &secret))
+		fatal("Bad reply from HSM: %s", tal_hex(tmpctx, msg));
+
+	runes->master = rune_new(runes, secret.data, ARRAY_SIZE(secret.data), NULL);
+
+	return runes;
+}
diff --git a/lightningd/runes.h b/lightningd/runes.h
new file mode 100644
index 000000000..d38052b44
--- /dev/null
+++ b/lightningd/runes.h
@@ -0,0 +1,7 @@
+#ifndef LIGHTNING_LIGHTNINGD_RUNES_H
+#define LIGHTNING_LIGHTNINGD_RUNES_H
+#include "config.h"
+
+struct runes *runes_init(struct lightningd *ld);
+
+#endif /* LIGHTNING_LIGHTNINGD_RUNES_H */
diff --git a/lightningd/test/run-find_my_abspath.c b/lightningd/test/run-find_my_abspath.c
index f43d3f660..b33f3ce50 100644
--- a/lightningd/test/run-find_my_abspath.c
+++ b/lightningd/test/run-find_my_abspath.c
@@ -187,6 +187,9 @@ void plugins_set_builtin_plugins_dir(struct plugins *plugins UNNEEDED,
 /* Generated stub for resend_closing_transactions */
 void resend_closing_transactions(struct lightningd *ld UNNEEDED)
 { fprintf(stderr, "resend_closing_transactions called!\n"); abort(); }
+/* Generated stub for runes_init */
+struct runes *runes_init(struct lightningd *ld UNNEEDED)
+{ fprintf(stderr, "runes_init called!\n"); abort(); }
 /* Generated stub for setup_color_and_alias */
 void setup_color_and_alias(struct lightningd *ld UNNEEDED)
 { fprintf(stderr, "setup_color_and_alias called!\n"); abort(); }