From 49fe1c8ed7aea1f109b4bcc4944ddcd0cc30117b Mon Sep 17 00:00:00 2001
From: Rusty Russell <rusty@rustcorp.com.au>
Date: Thu, 29 Sep 2022 13:18:53 +0930
Subject: [PATCH] lightningd: have `makesecret` take `hex` or `string` (just
 like `datastore`)

Changelog-Added: JSON-RPC: `makesecret` can take a string argument instead of hex.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
 doc/lightning-makesecret.7.md       | 10 +++-------
 doc/schemas/makesecret.request.json |  8 +++++---
 lightningd/hsm_control.c            | 20 +++++++++++++++++---
 tests/test_misc.py                  |  4 ++++
 4 files changed, 29 insertions(+), 13 deletions(-)

diff --git a/doc/lightning-makesecret.7.md b/doc/lightning-makesecret.7.md
index 2a713ded4..fc54dd514 100644
--- a/doc/lightning-makesecret.7.md
+++ b/doc/lightning-makesecret.7.md
@@ -4,14 +4,15 @@ lightning-makesecret -- Command for deriving pseudorandom key from HSM
 SYNOPSIS
 --------
 
-**makesecret** *hex*
+**makesecret** [*hex*] [*string*]
 
 DESCRIPTION
 -----------
 
 The **makesecret** RPC command derives a secret key from the HSM_secret.
 
-The *hex* can be any hex data.
+One of *hex* or *string* must be specified: *hex* can be any hex data,
+*string* is a UTF-8 string interpreted literally.
 
 RETURN VALUE
 ------------
@@ -32,11 +33,6 @@ AUTHOR
 
 Aditya <<aditya.sharma20111@gmail.com>> is mainly responsible.
 
-SEE ALSO
---------
-
-lightning-getsharedsecret(7)
-
 RESOURCES
 ---------
 
diff --git a/doc/schemas/makesecret.request.json b/doc/schemas/makesecret.request.json
index c26e3ce4b..5059babd0 100644
--- a/doc/schemas/makesecret.request.json
+++ b/doc/schemas/makesecret.request.json
@@ -2,13 +2,15 @@
   "$schema": "http://json-schema.org/draft-07/schema#",
   "type": "object",
   "additionalProperties": false,
-  "required": [
-    "hex"
-  ],
+  "required": [],
   "properties": {
     "hex": {
       "type": "hex",
       "description": "This will be used for deriving the secret"
+    },
+    "string": {
+      "type": "string",
+      "description": "This will be used for deriving the secret"
     }
   }
 }
diff --git a/lightningd/hsm_control.c b/lightningd/hsm_control.c
index c5252fc3b..f360d813a 100644
--- a/lightningd/hsm_control.c
+++ b/lightningd/hsm_control.c
@@ -131,16 +131,30 @@ static struct command_result *json_makesecret(struct command *cmd,
 					   const jsmntok_t *obj UNNEEDED,
 					   const jsmntok_t *params)
 {
-	u8 *info;
+	u8 *data;
+	const char *strdata;
 	struct json_stream *response;
 	struct secret secret;
 
 	if (!param(cmd, buffer, params,
-		   p_req("hex", param_bin_from_hex, &info),
+		   p_opt("hex", param_bin_from_hex, &data),
+		   p_opt("string", param_string, &strdata),
 		   NULL))
 		return command_param_failed();
 
-	u8 *msg = towire_hsmd_derive_secret(cmd, info);
+	if (strdata) {
+		if (data)
+			return command_fail(cmd, JSONRPC2_INVALID_PARAMS,
+					    "Cannot have both hex and string");
+		data = tal_dup_arr(cmd, u8, (u8 *)strdata, strlen(strdata), 0);
+	} else {
+		if (!data)
+			return command_fail(cmd, JSONRPC2_INVALID_PARAMS,
+					    "Must have either hex or string");
+	}
+
+
+	u8 *msg = towire_hsmd_derive_secret(cmd, data);
 	if (!wire_sync_write(cmd->ld->hsm_fd, take(msg)))
 		return command_fail(cmd, LIGHTNINGD,
                      "Could not write to HSM: %s", strerror(errno));
diff --git a/tests/test_misc.py b/tests/test_misc.py
index cb54b58d3..b301286a3 100644
--- a/tests/test_misc.py
+++ b/tests/test_misc.py
@@ -2281,6 +2281,10 @@ def test_makesecret(node_factory):
     assert l1.rpc.makesecret(hex="736362207365637265")["secret"] != secret
     assert l1.rpc.makesecret(hex="7363622073656372657401")["secret"] != secret
 
+    # Using string works!
+    assert l1.rpc.makesecret(string="scb secret")["secret"] == secret
+    assert l1.rpc.makesecret(None, "scb secret")["secret"] == secret
+
 
 def test_staticbackup(node_factory):
     """