FREESCAPE: added code to decrypt some driller releases for atari

Author: neuromancer

engines/freescape/detection.cpp

@@ -157,7 +157,20 @@ static const ADGameDescription gameDescriptions[] = {
 		ADGF_NO_FLAGS,
 		GUIO4(GUIO_NOMIDI, GUIO_RENDEREGA, GUIO_RENDERCGA, GAMEOPTION_AUTOMATIC_DRILLING)
 	},
-	{
+	{ // Retail release
+		"driller",
+		"",
+		{
+			{"x.prg", 0, "d002983a8b652f25b18a09425db78c4c", 293159},
+			{"playseq.prg", 0, "535e9f6baf132831aa7fa066a06f242e", 973},
+			AD_LISTEND
+		},
+		Common::EN_ANY,
+		Common::kPlatformAtariST,
+		GF_ATARI_RETAIL,
+		GUIO2(GUIO_NOMIDI, GAMEOPTION_AUTOMATIC_DRILLING)
+	},
+	{ // Budget release
 		"driller",
 		"",
 		{
@@ -167,7 +180,7 @@ static const ADGameDescription gameDescriptions[] = {
 		},
 		Common::EN_ANY,
 		Common::kPlatformAtariST,
-		ADGF_NO_FLAGS,
+		GF_ATARI_BUDGET,
 		GUIO2(GUIO_NOMIDI, GAMEOPTION_AUTOMATIC_DRILLING)
 	},
 	{
@@ -340,7 +353,7 @@ static const ADGameDescription gameDescriptions[] = {
 		"spacestationoblivion",
 		"",
 		{
-			{"x.prg", 0, "10c556ee637bf03bcc1a051277542102", 293264},
+			{"x.prg", 0, "bf546ee243c38f51d9beb25c203ccb93", 292624},
 			AD_LISTEND
 		},
 		Common::EN_ANY,

engines/freescape/freescape.h

@@ -427,6 +427,8 @@ enum DrillerReleaseFlags {
 		GF_CPC_RETAIL2 = (1 << 6),
 		GF_CPC_BUDGET = (1 << 7),
 		GF_CPC_VIRTUALWORLDS = (1 << 8),
+		GF_ATARI_RETAIL = (1 << 9),
+		GF_ATARI_BUDGET = (1 << 10),
 };
 
 class DrillerEngine : public FreescapeEngine {
@@ -509,6 +511,8 @@ class DrillerEngine : public FreescapeEngine {
 
 	uint32 getPixel8bitTitleImage(int index);
 	void renderPixels8bitTitleImage(Graphics::ManagedSurface *surface, int &i, int &j, int pixels);
+
+	Common::SeekableReadStream *decryptFileAtari(const Common::String filename);
 };
 
 class DarkEngine : public FreescapeEngine {

engines/freescape/games/driller/atari.cpp

@@ -19,34 +19,83 @@
  *
  */
 #include "common/file.h"
+#include "common/memstream.h"
 
 #include "freescape/freescape.h"
 #include "freescape/language/8bitDetokeniser.h"
 
 namespace Freescape {
 
-void DrillerEngine::loadAssetsAtariFullGame() {
+Common::SeekableReadStream *DrillerEngine::decryptFileAtari(const Common::String filename) {
 	Common::File file;
-	file.open("x.prg");
-
+	file.open(filename);
 	if (!file.isOpen())
-		error("Failed to open 'x.prg' executable for AtariST");
-
-	_border = loadAndConvertNeoImage(&file, 0x1371a);
-	byte *palette = (byte *)malloc(16 * 3);
-	for (int i = 0; i < 16; i++) { // gray scale palette
-		palette[i * 3 + 0] = i * (255 / 16);
-		palette[i * 3 + 1] = i * (255 / 16);
-		palette[i * 3 + 2] = i * (255 / 16);
+		error("Failed to open %s", filename.c_str());
+
+	int size = file.size();
+	byte *encryptedBuffer = (byte *)malloc(size);
+	file.read(encryptedBuffer, size);
+	file.close();
+
+	byte *a6 = encryptedBuffer + 0x118;
+	byte *a5 = encryptedBuffer + size - 4;
+	uint64 key = 0xb9f11bce;
+
+	while (a6 <= a5) {
+		uint64 d0 = (a6[0] << 24) | (a6[1] << 16) | (a6[2] << 8) | a6[3];
+		d0 += key;
+		d0 = uint32(d0);
+
+		a6[0] = byte((d0 >> 24) & 0xFF);
+		a6[1] = byte((d0 >> 16) & 0xFF);
+		a6[2] = byte((d0 >> 8) & 0xFF);
+		a6[3] = byte(d0 & 0xFF);
+
+		key += 0x51684624;
+		key = uint32(key);
+		a6 += 4;
+	}
+
+	return (new Common::MemoryReadStream(encryptedBuffer, size));
+}
+
+void DrillerEngine::loadAssetsAtariFullGame() {
+
+	if (_variant & GF_ATARI_RETAIL) {
+		Common::SeekableReadStream *stream = decryptFileAtari("x.prg");
+
+		_border = loadAndConvertNeoImage(stream, 0x14b96);
+		_title = loadAndConvertNeoImage(stream, 0x1c916);
+
+		loadFonts(stream, 0x8a92);
+		loadMessagesFixedSize(stream, 0xda22, 14, 20);
+		loadGlobalObjects(stream, 0xd116, 8);
+		load8bitBinary(stream, 0x2afb8, 16);
+		loadPalettes(stream, 0x2ab76);
+		//loadSoundsFx(&file, 0x30da6, 25);
+	} else if (_variant & GF_ATARI_BUDGET) {
+		Common::File file;
+		file.open("x.prg");
+
+		if (!file.isOpen())
+			error("Failed to open 'x.prg' executable for AtariST");
+
+		_border = loadAndConvertNeoImage(&file, 0x1371a);
+		byte *palette = (byte *)malloc(16 * 3);
+		for (int i = 0; i < 16; i++) { // gray scale palette
+			palette[i * 3 + 0] = i * (255 / 16);
+			palette[i * 3 + 1] = i * (255 / 16);
+			palette[i * 3 + 2] = i * (255 / 16);
+		}
+		_title = loadAndConvertNeoImage(&file, 0x10, palette);
+
+		loadFonts(&file, 0x8a32);
+		loadMessagesFixedSize(&file, 0xc5d8, 14, 20);
+		loadGlobalObjects(&file, 0xbccc, 8);
+		load8bitBinary(&file, 0x29b3c, 16);
+		loadPalettes(&file, 0x296fa);
+		loadSoundsFx(&file, 0x30da6, 25);
 	}
-	_title = loadAndConvertNeoImage(&file, 0x10, palette);
-
-	loadFonts(&file, 0x8a32);
-	loadMessagesFixedSize(&file, 0xc5d8, 14, 20);
-	loadGlobalObjects(&file, 0xbccc, 8);
-	load8bitBinary(&file, 0x29b3c, 16);
-	loadPalettes(&file, 0x296fa);
-	loadSoundsFx(&file, 0x30da6, 25);
 }
 
 void DrillerEngine::loadAssetsAtariDemo() {