Expose SHA256 algorithm to Lua (#14403)

Co-authored-by: chmodsayshello <chmodsayshello@hotmail.com>

doc/lua_api.md

@@ -5484,6 +5484,9 @@ Utilities
 * `minetest.sha1(data, [raw])`: returns the sha1 hash of data
     * `data`: string of data to hash
     * `raw`: return raw bytes instead of hex digits, default: false
+* `minetest.sha256(data, [raw])`: returns the sha256 hash of data
+    * `data`: string of data to hash
+    * `raw`: return raw bytes instead of hex digits, default: false
 * `minetest.colorspec_to_colorstring(colorspec)`: Converts a ColorSpec to a
   ColorString. If the ColorSpec is invalid, returns `nil`.
     * `colorspec`: The ColorSpec to convert

games/devtest/mods/unittests/misc.lua

@@ -111,6 +111,13 @@ unittests.register("test_punch_node", function(_, pos)
 	-- currently failing: assert(on_punch_called)
 end, {map=true})
 
+local function test_hashing()
+	local input = "hello\000world"
+	assert(core.sha1(input) == "f85b420f1e43ebf88649dfcab302b898d889606c")
+	assert(core.sha256(input) == "b206899bc103669c8e7b36de29d73f95b46795b508aa87d612b2ce84bfb29df2")
+end
+unittests.register("test_hashing", test_hashing)
+
 local function test_compress()
 	-- This text should be compressible, to make sure the results are... normal
 	local text = "The\000 icey canoe couldn't move very well on the\128 lake. The\000 ice was too stiff and the icey canoe's paddles simply wouldn't punch through."

src/script/lua_api/l_util.cpp

@@ -42,6 +42,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "version.h"
 #include "util/hex.h"
 #include "util/sha1.h"
+#include "util/sha256.h"
 #include "util/png.h"
 #include <cstdio>
 
@@ -566,6 +567,27 @@ int ModApiUtil::l_sha1(lua_State *L)
 	return 1;
 }
 
+int ModApiUtil::l_sha256(lua_State *L)
+{
+	NO_MAP_LOCK_REQUIRED;
+
+	auto data = readParam<std::string_view>(L, 1);
+	bool hex = !lua_isboolean(L, 2) || !readParam<bool>(L, 2);
+	
+	std::string data_sha256;
+	data_sha256.resize(SHA256_DIGEST_LENGTH);
+	SHA256(reinterpret_cast<const unsigned char*>(data.data()), data.size(),
+		reinterpret_cast<unsigned char *>(data_sha256.data()));
+
+	if (hex) {
+		lua_pushstring(L, hex_encode(data_sha256).c_str());
+	} else {
+		lua_pushlstring(L, data_sha256.data(), data_sha256.size());
+	}
+
+	return 1;
+}
+
 // colorspec_to_colorstring(colorspec)
 int ModApiUtil::l_colorspec_to_colorstring(lua_State *L)
 {
@@ -690,6 +712,7 @@ void ModApiUtil::Initialize(lua_State *L, int top)
 
 	API_FCT(get_version);
 	API_FCT(sha1);
+	API_FCT(sha256);
 	API_FCT(colorspec_to_colorstring);
 	API_FCT(colorspec_to_bytes);
 
@@ -723,6 +746,7 @@ void ModApiUtil::InitializeClient(lua_State *L, int top)
 
 	API_FCT(get_version);
 	API_FCT(sha1);
+	API_FCT(sha256);
 	API_FCT(colorspec_to_colorstring);
 	API_FCT(colorspec_to_bytes);
 
@@ -766,6 +790,7 @@ void ModApiUtil::InitializeAsync(lua_State *L, int top)
 
 	API_FCT(get_version);
 	API_FCT(sha1);
+	API_FCT(sha256);
 	API_FCT(colorspec_to_colorstring);
 	API_FCT(colorspec_to_bytes);
 

src/script/lua_api/l_util.h

@@ -113,6 +113,9 @@ private:
 	// sha1(string, raw)
 	static int l_sha1(lua_State *L);
 
+	// sha256(string, raw)
+	static int l_sha256(lua_State *L);
+
 	// colorspec_to_colorstring(colorspec)
 	static int l_colorspec_to_colorstring(lua_State *L);