Add sha1 to lua utils. (#6563)

Author: basicer

doc/client_lua_api.md

@@ -630,6 +630,9 @@ Minetest namespace reference
   version entirely. To check for the presence of engine features, test
   whether the functions exported by the wanted features exist. For example:
   `if minetest.check_for_falling then ... end`.
+* `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
 
 ### Logging
 * `minetest.debug(...)`

doc/lua_api.txt

@@ -2391,6 +2391,9 @@ Strings that need to be translated can contain several escapes, preceded by `@`.
   version entirely. To check for the presence of engine features, test
   whether the functions exported by the wanted features exist. For example:
   `if minetest.check_for_falling then ... end`.
+* `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
 
 ### Logging
 * `minetest.debug(...)`

src/script/lua_api/l_util.cpp

@@ -37,6 +37,8 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "util/base64.h"
 #include "config.h"
 #include "version.h"
+#include "util/hex.h"
+#include "util/sha1.h"
 #include <algorithm>
 
 
@@ -423,6 +425,32 @@ int ModApiUtil::l_get_version(lua_State *L)
 	return 1;
 }
 
+int ModApiUtil::l_sha1(lua_State *L)
+{
+	NO_MAP_LOCK_REQUIRED;
+	size_t size;
+	const char *data = luaL_checklstring(L, 1, &size);
+	bool hex = !lua_isboolean(L, 2) || !lua_toboolean(L, 2);
+
+	// Compute actual checksum of data
+	std::string data_sha1;
+	{
+		SHA1 ctx;
+		ctx.addBytes(data, size);
+		unsigned char *data_tmpdigest = ctx.getDigest();
+		data_sha1.assign((char*) data_tmpdigest, 20);
+		free(data_tmpdigest);
+	}
+
+	if (hex) {
+		std::string sha1_hex = hex_encode(data_sha1);
+		lua_pushstring(L, sha1_hex.c_str());
+	} else {
+		lua_pushlstring(L, data_sha1.data(), data_sha1.size());
+	}
+
+	return 1;
+}
 
 void ModApiUtil::Initialize(lua_State *L, int top)
 {
@@ -455,6 +483,7 @@ void ModApiUtil::Initialize(lua_State *L, int top)
 	API_FCT(decode_base64);
 
 	API_FCT(get_version);
+	API_FCT(sha1);
 
 	LuaSettings::create(L, g_settings, g_settings_path);
 	lua_setfield(L, top, "settings");
@@ -478,6 +507,7 @@ void ModApiUtil::InitializeClient(lua_State *L, int top)
 	API_FCT(decode_base64);
 
 	API_FCT(get_version);
+	API_FCT(sha1);
 }
 
 void ModApiUtil::InitializeAsync(lua_State *L, int top)
@@ -503,6 +533,7 @@ void ModApiUtil::InitializeAsync(lua_State *L, int top)
 	API_FCT(decode_base64);
 
 	API_FCT(get_version);
+	API_FCT(sha1);
 
 	LuaSettings::create(L, g_settings, g_settings_path);
 	lua_setfield(L, top, "settings");

src/script/lua_api/l_util.h

@@ -92,6 +92,9 @@ class ModApiUtil : public ModApiBase
 	// get_version()
 	static int l_get_version(lua_State *L);
 
+	// sha1(string, raw)
+	static int l_sha1(lua_State *L);
+
 public:
 	static void Initialize(lua_State *L, int top);
 	static void InitializeAsync(lua_State *L, int top);