give Lua access to tomcrypt's SHA256

This adds Lua hooks to CryptManager for libtomcrypt's SHA256 hash
function.  It follows along with the C++ patterns Glenn wrote a decade
and a half ago for CryptMananger's MD5 and SHA1 hooks.

StepMania's CMakeProject-tomcrypt file has been updated to build with
sha256 symbols.  Invoking cmake to build with system tomcrypt works fine
as-is.

Note that these functions return binary formatted strings, but themers
can convert to hexadecimal format using the global Lua function
BinaryToHex().

Docs/Luadoc/Lua.xml

@@ -12,6 +12,7 @@
 		<Function name='BGFitChoiceExample'/>
 		<Function name='BGFitInputActor'/>
 		<Function name='Basename'/>
+		<Function name='BinaryToHex'/>
 		<Function name='BoostColor'/>
 		<Function name='Brightness'/>
 		<Function name='Center1Player'/>
@@ -757,6 +758,8 @@
 			<Function name='MD5String'/>
 			<Function name='SHA1File'/>
 			<Function name='SHA1String'/>
+			<Function name='SHA256File'/>
+			<Function name='SHA256String'/>
 		</Class>
 		<Class name='CubicSplineN'>
 			<Function name='solve'/>

Docs/Luadoc/LuaDocumentation.xml

@@ -74,6 +74,10 @@ save yourself some time, copy this for undocumented things:
 	<Function name='Basename' return='string' arguments='string path'>
 		Returns the last named component of <code>path</code>.  For example, passing in <code>"/path/to/file.txt"</code> will return <code>"file.txt"</code>, while <code>"/path/to/some/directory/"</code> will return <code>"directory"</code>.
 	</Function>
+	<Function name='BinaryToHex' return='string' arguments='string s'>
+		Converts a binary formatted string to hexadecimal format.
+		This can be useful in conjunction with <Link class="CryptManager" />'s MD5 and SHA functions.
+	</Function>
 	<Function name='BoostColor' theme='_fallback' return='color' arguments='color c, float fBoost'>
 		[02 Colors.lua] Returns the color that results from multiplying <code>c</code>'s R, G, and B values by <code>fBoost</code>.
 	</Function>
@@ -2510,6 +2514,14 @@ Def.BitmapText{
 	<Function name='SHA1String' return='string' arguments='string s'>
 		Returns the SHA-1 hash for <code>s</code>.
 	</Function>
+	<Function name='SHA256File' return='string' arguments='string sPath'>
+		Returns the SHA-256 hash for the file at <code>sPath</code> as a binary formatted string.<br />
+		You can use <Link class='GLOBAL' function='BinaryToHex' /> to convert to hexadecimal format.
+	</Function>
+	<Function name='SHA256String' return='string' arguments='string s'>
+		Returns the SHA-256 hash for <code>s</code> as a binary formatted string.<br />
+		You can use <Link class='GLOBAL' function='BinaryToHex' /> to convert to hexadecimal format.
+	</Function>
 </Class>
 <Class name='CubicSplineN'>
 	<Description>

extern/CMakeProject-tomcrypt.cmake

@@ -823,6 +823,7 @@ else()
   sm_add_compile_definition("tomcrypt" LTC_DEVRANDOM)
 
   # Common formulas used by our app.
+  sm_add_compile_definition("tomcrypt" LTC_SHA256)
   sm_add_compile_definition("tomcrypt" LTC_SHA1)
   sm_add_compile_definition("tomcrypt" LTC_MD5)
 

src/CryptManager.cpp

@@ -420,6 +420,37 @@ RString CryptManager::GetSHA1ForFile( RString fn )
 	return RString( (const char *) digest, sizeof(digest) );
 }
 
+RString CryptManager::GetSHA256ForString( RString sData )
+{
+	unsigned char digest[32];
+
+	int iHash = register_hash( &sha256_desc );
+
+	hash_state hash;
+	hash_descriptor[iHash].init( &hash );
+	hash_descriptor[iHash].process( &hash, (const unsigned char *) sData.data(), sData.size() );
+	hash_descriptor[iHash].done( &hash, digest );
+
+	return RString( (const char *) digest, sizeof(digest) );
+}
+
+RString CryptManager::GetSHA256ForFile( RString fn )
+{
+	RageFile file;
+	if( !file.Open( fn, RageFile::READ ) )
+	{
+		LOG->Warn( "GetSHA256: Failed to open file '%s'", fn.c_str() );
+		return RString();
+	}
+	int iHash = register_hash( &sha256_desc );
+	ASSERT( iHash >= 0 );
+
+	unsigned char digest[32];
+	HashFile( file, digest, iHash );
+
+	return RString( (const char *) digest, sizeof(digest) );
+}
+
 RString CryptManager::GetPublicKeyFileName()
 {
 	return PUBLIC_KEY_PATH;
@@ -478,6 +509,20 @@ public:
 		lua_pushlstring(L, sha1fout, sha1fout.size());
 		return 1;
 	}
+	static int SHA256String( T* p, lua_State *L )
+	{
+		RString sha256out;
+		sha256out = p->GetSHA256ForString(SArg(1));
+		lua_pushlstring(L, sha256out, sha256out.size());
+		return 1;
+	}
+	static int SHA256File( T* p, lua_State *L )
+	{
+		RString sha256fout;
+		sha256fout = p->GetSHA256ForFile(SArg(1));
+		lua_pushlstring(L, sha256fout, sha256fout.size());
+		return 1;
+	}
 	static int GenerateRandomUUID( T* p, lua_State *L )
 	{
 		RString uuidOut;
@@ -492,6 +537,8 @@ public:
 		ADD_METHOD( MD5File );
 		ADD_METHOD( SHA1String );
 		ADD_METHOD( SHA1File );
+		ADD_METHOD( SHA256String );
+		ADD_METHOD( SHA256File );
 		ADD_METHOD( GenerateRandomUUID );
 	}
 };

src/CryptManager.h

@@ -24,10 +24,12 @@ public:
 	static void GetRandomBytes( void *pData, int iBytes );
 	static RString GenerateRandomUUID();
 
-	static RString GetMD5ForFile( RString fn );		// in binary
-	static RString GetMD5ForString( RString sData );	// in binary
-	static RString GetSHA1ForString( RString sData );	// in binary
-	static RString GetSHA1ForFile( RString fn );		// in binary
+	static RString GetMD5ForFile( RString fn );         // in binary
+	static RString GetMD5ForString( RString sData );    // in binary
+	static RString GetSHA1ForString( RString sData );   // in binary
+	static RString GetSHA1ForFile( RString fn );        // in binary
+	static RString GetSHA256ForString( RString sData ); // in binary
+	static RString GetSHA256ForFile( RString fn );      // in binary
 
 	static RString GetPublicKeyFileName();
 
@@ -42,7 +44,7 @@ extern CryptManager*	CRYPTMAN;	// global and accessible from anywhere in our pro
 /*
  * (c) 2004 Chris Danford
  * All rights reserved.
- * 
+ *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the
  * "Software"), to deal in the Software without restriction, including
@@ -52,7 +54,7 @@ extern CryptManager*	CRYPTMAN;	// global and accessible from anywhere in our pro
  * copyright notice(s) and this permission notice appear in all copies of
  * the Software and that both the above copyright notice(s) and this
  * permission notice appear in supporting documentation.
- * 
+ *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF