From ae7045f67efede5eafa5af3279ab1d88c0facec5 Mon Sep 17 00:00:00 2001
From: Fabio Alessandrelli <fabio.alessandrelli@gmail.com>
Date: Fri, 14 Jun 2024 02:30:32 +0200
Subject: [PATCH] [Crypto] Expose OS.get_entropy

---
 core/core_bind.cpp | 9 +++++++++
 core/core_bind.h   | 1 +
 doc/classes/OS.xml | 8 ++++++++
 3 files changed, 18 insertions(+)

diff --git a/core/core_bind.cpp b/core/core_bind.cpp
index d6719e715fc..a1b7b81111d 100644
--- a/core/core_bind.cpp
+++ b/core/core_bind.cpp
@@ -194,6 +194,14 @@ void ResourceSaver::_bind_methods() {
 
 ////// OS //////
 
+PackedByteArray OS::get_entropy(int p_bytes) {
+	PackedByteArray pba;
+	pba.resize(p_bytes);
+	Error err = ::OS::get_singleton()->get_entropy(pba.ptrw(), p_bytes);
+	ERR_FAIL_COND_V(err != OK, PackedByteArray());
+	return pba;
+}
+
 String OS::get_system_ca_certificates() {
 	return ::OS::get_singleton()->get_system_ca_certificates();
 }
@@ -577,6 +585,7 @@ String OS::get_unique_id() const {
 OS *OS::singleton = nullptr;
 
 void OS::_bind_methods() {
+	ClassDB::bind_method(D_METHOD("get_entropy", "size"), &OS::get_entropy);
 	ClassDB::bind_method(D_METHOD("get_system_ca_certificates"), &OS::get_system_ca_certificates);
 	ClassDB::bind_method(D_METHOD("get_connected_midi_inputs"), &OS::get_connected_midi_inputs);
 	ClassDB::bind_method(D_METHOD("open_midi_inputs"), &OS::open_midi_inputs);
diff --git a/core/core_bind.h b/core/core_bind.h
index 1452368f60e..b142a2fbbd9 100644
--- a/core/core_bind.h
+++ b/core/core_bind.h
@@ -134,6 +134,7 @@ public:
 		RENDERING_DRIVER_D3D12,
 	};
 
+	PackedByteArray get_entropy(int p_bytes);
 	String get_system_ca_certificates();
 
 	virtual PackedStringArray get_connected_midi_inputs();
diff --git a/doc/classes/OS.xml b/doc/classes/OS.xml
index a3fd15a46d4..3d048e2f634 100644
--- a/doc/classes/OS.xml
+++ b/doc/classes/OS.xml
@@ -262,6 +262,14 @@
 				[b]Note:[/b] This method is not supported on the Web platform. It returns an empty string.
 			</description>
 		</method>
+		<method name="get_entropy">
+			<return type="PackedByteArray" />
+			<param index="0" name="size" type="int" />
+			<description>
+				Generates a [PackedByteArray] of cryptographically secure random bytes with given [param size].
+				[b]Note:[/b] Generating large quantities of bytes using this method can result in locking and entropy of lower quality on most platforms. Using [method Crypto.generate_random_bytes] is preferred in most cases.
+			</description>
+		</method>
 		<method name="get_environment" qualifiers="const">
 			<return type="String" />
 			<param index="0" name="variable" type="String" />