From 3da9c6bbb9910ce7f8fc29f9c5da758dbb50cb9c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20Vejpustek?= <ondrej.vejpustek@satoshilabs.com>
Date: Tue, 6 Aug 2024 17:07:05 +0200
Subject: [PATCH] fix(crypto): forbid public key derivation for curve25519,
 ed25519 and cardano

[no changelog]
---
 crypto/bip32.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/crypto/bip32.c b/crypto/bip32.c
index cb67834764..b78d31159b 100644
--- a/crypto/bip32.c
+++ b/crypto/bip32.c
@@ -209,6 +209,8 @@ int hdnode_private_ckd_bip32(HDNode *inout, uint32_t i) {
     memcpy(data + 1, inout->private_key, 32);
   } else {  // public derivation
     if (!inout->curve->params) {
+      // SLIP-10 doesn't support private key to private key non-hardened
+      // derivation for curve25519 and ed25519
       return 0;
     }
     if (hdnode_fill_public_key(inout) != 0) {
@@ -321,6 +323,13 @@ int hdnode_public_ckd_cp(const ecdsa_curve *curve, const curve_point *parent,
 int hdnode_public_ckd(HDNode *inout, uint32_t i) {
   curve_point parent = {0}, child = {0};
 
+  if (!inout->curve->params) {
+    // SLIP-10 doesn't support public key to public key derivation for
+    // curve25519 and ed25519, Cardano BIP32-ed22519 public key to public key
+    // derivation is not implemented
+    return 0;
+  }
+
   if (!ecdsa_read_pubkey(inout->curve->params, inout->public_key, &parent)) {
     return 0;
   }