From 49ed0a4b9e9a11bade7d84fc7e9a4f8135ee5d67 Mon Sep 17 00:00:00 2001
From: niftynei <niftynei@gmail.com>
Date: Fri, 7 Oct 2022 14:13:38 -0500
Subject: [PATCH] psbt: wipe global tx scriptSig/witness data after saved to
 PSBT

The global tx should be "free from sin" (no scriptSig data, no witness
stacks).
---
 bitcoin/psbt.c                  | 9 +++++++++
 bitcoin/test/run-psbt-from-tx.c | 7 +++++--
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/bitcoin/psbt.c b/bitcoin/psbt.c
index 6f346b9db..13692c50b 100644
--- a/bitcoin/psbt.c
+++ b/bitcoin/psbt.c
@@ -90,12 +90,21 @@ struct wally_psbt *new_psbt(const tal_t *ctx, const struct wally_tx *wtx)
 								     wtx->inputs[i].script,
 								     wtx->inputs[i].script_len);
 			assert(wally_err == WALLY_OK);
+
+			/* Clear out script sig data */
+			psbt->tx->inputs[i].script_len = 0;
+			tal_free(psbt->tx->inputs[i].script);
+			psbt->tx->inputs[i].script = NULL;
 		}
 		if (wtx->inputs[i].witness) {
 			wally_err =
 				wally_psbt_input_set_final_witness(&psbt->inputs[i],
 								   wtx->inputs[i].witness);
 			assert(wally_err == WALLY_OK);
+
+			/* Delete the witness data */
+			wally_tx_witness_stack_free(psbt->tx->inputs[i].witness);
+			psbt->tx->inputs[i].witness = NULL;
 		}
 	}
 
diff --git a/bitcoin/test/run-psbt-from-tx.c b/bitcoin/test/run-psbt-from-tx.c
index bbcd1cd52..5aefcb9ed 100644
--- a/bitcoin/test/run-psbt-from-tx.c
+++ b/bitcoin/test/run-psbt-from-tx.c
@@ -101,9 +101,12 @@ int main(int argc, char *argv[])
 
 	tx2 = fromwire_bitcoin_tx(tmpctx,
 				  cast_const2(const u8 **, &msg), &len);
+	assert(tx2 != NULL);
 
-	/* FIXME: this should not be null! */
-	assert(tx2 == NULL);
+	/* Witness/scriptsig data is saved down into psbt */
+	assert(tx2->psbt->num_inputs == 1);
+	assert(tx2->psbt->inputs[0].final_scriptsig_len > 0);
+	assert(tx2->psbt->inputs[0].final_witness != NULL);
 
 	common_shutdown();
 	return 0;