NEVERHOOD: Check that the supplied nhc.exe is the correct one

4 files changed, 348 insertions, 4 deletions

diff --git a/devtools/create_neverhood/create_neverhood.cpp b/devtools/create_neverhood/create_neverhood.cpp
index 323066d8b1..f34f20882c 100644
--- a/devtools/create_neverhood/create_neverhood.cpp
+++ b/devtools/create_neverhood/create_neverhood.cpp
@@ -32,10 +32,16 @@
 
 #include <vector>
 #include "create_neverhood.h"
+#include "md5.h"
 #include "tables.h"
 
 const int DAT_VERSION = 0;
 
+// The MD5 hash of the nhc.exe used to extract the tables from
+const uint8 kNhcExeMd5[16] = {
+	0x37, 0xD6, 0x54, 0xA2, 0xA7, 0xBB, 0xB0, 0x1F,
+	0x8C, 0x41, 0x9A, 0xB8, 0x49, 0xFF, 0x29, 0xD4};
+
 uint32 dataSize;
 byte *data;
 uint32 dataStart = 0x004AE000;
@@ -48,12 +54,33 @@ class NavigationList;
 
 void addMessageList(uint32 messageListCount, uint32 messageListOffset);
 
-void loadExe(const char *filename) {
+bool loadExe(const char *filename) {
 	FILE *exe = fopen(filename, "rb");
+	if (!exe) {
+		printf("Could not open nhc.exe for reading! Quitting...\n");
+		return false;
+	}
 	dataSize = fileSize(exe);
 	data = new byte[dataSize];
 	fread(data, dataSize, 1, exe);
 	fclose(exe);
+	return true;
+}
+
+bool validateMd5() {
+	uint8 digest[16];
+	
+	md5_buffer(data, dataSize, digest);
+	
+	printf("MD5 of nhc.exe is %02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x\n",
+		digest[0], digest[1], digest[2], digest[3], digest[4], digest[5], digest[6], digest[7], 
+		digest[8], digest[9], digest[10], digest[11], digest[12], digest[13], digest[14], digest[15]);
+	
+	if (memcmp(kNhcExeMd5, digest, 16)) {
+		printf("MD5 hash of nhc.exe doesn't match the expected value! Quitting...\n");
+		return false;
+	}
+	return true;
 }
 
 byte *getData(uint32 offset) {
@@ -506,9 +533,11 @@ void addMessageList(uint32 messageListCount, uint32 messageListOffset) {
 
 int main(int argc, char *argv[]) {
 
-	FILE *datFile;
+	if (!loadExe("nhc.exe") ||
+		!validateMd5())
+		return 1;
 
-	loadExe("nhc.exe");
+	FILE *datFile;
 
 	hitRectLists.loadListVector(hitRectListOffsets);
 	rectLists.loadListVector(rectListOffsets);
@@ -516,7 +545,7 @@ int main(int argc, char *argv[]) {
 	navigationLists.loadListVector(navigationListOffsets);
 	sceneInfo140Items.loadVector(sceneInfo140Offsets);
 	sceneInfo2700Items.loadVector(sceneInfo2700Offsets);
-	    
+
 	datFile = fopen("neverhood.dat", "wb");
 
 	writeUint32LE(datFile, 0x11223344); // Some magic
diff --git a/devtools/create_neverhood/md5.cpp b/devtools/create_neverhood/md5.cpp
new file mode 100644
index 0000000000..50f7406a47
--- /dev/null
+++ b/devtools/create_neverhood/md5.cpp
@@ -0,0 +1,273 @@
+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ */
+
+// Disable symbol overrides so that we can use system headers.
+#define FORBIDDEN_SYMBOL_ALLOW_ALL
+
+#include "md5.h"
+
+#define GET_UINT32(n, b, i)	(n) = READ_LE_UINT32(b + i)
+#define PUT_UINT32(n, b, i)	WRITE_LE_UINT32(b + i, n)
+
+void md5_starts(md5_context *ctx) {
+	ctx->total[0] = 0;
+	ctx->total[1] = 0;
+
+	ctx->state[0] = 0x67452301;
+	ctx->state[1] = 0xEFCDAB89;
+	ctx->state[2] = 0x98BADCFE;
+	ctx->state[3] = 0x10325476;
+}
+
+static void md5_process(md5_context *ctx, const uint8 data[64]) {
+	uint32 X[16], A, B, C, D;
+
+	GET_UINT32(X[0],  data,  0);
+	GET_UINT32(X[1],  data,  4);
+	GET_UINT32(X[2],  data,  8);
+	GET_UINT32(X[3],  data, 12);
+	GET_UINT32(X[4],  data, 16);
+	GET_UINT32(X[5],  data, 20);
+	GET_UINT32(X[6],  data, 24);
+	GET_UINT32(X[7],  data, 28);
+	GET_UINT32(X[8],  data, 32);
+	GET_UINT32(X[9],  data, 36);
+	GET_UINT32(X[10], data, 40);
+	GET_UINT32(X[11], data, 44);
+	GET_UINT32(X[12], data, 48);
+	GET_UINT32(X[13], data, 52);
+	GET_UINT32(X[14], data, 56);
+	GET_UINT32(X[15], data, 60);
+
+#define S(x, n) ((x << n) | ((x & 0xFFFFFFFF) >> (32 - n)))
+
+#define P(a, b, c, d, k, s, t)                    \
+{                                                 \
+	a += F(b,c,d) + X[k] + t; a = S(a,s) + b; \
+}
+
+	A = ctx->state[0];
+	B = ctx->state[1];
+	C = ctx->state[2];
+	D = ctx->state[3];
+
+#define F(x, y, z) (z ^ (x & (y ^ z)))
+
+	P(A, B, C, D,  0,  7, 0xD76AA478);
+	P(D, A, B, C,  1, 12, 0xE8C7B756);
+	P(C, D, A, B,  2, 17, 0x242070DB);
+	P(B, C, D, A,  3, 22, 0xC1BDCEEE);
+	P(A, B, C, D,  4,  7, 0xF57C0FAF);
+	P(D, A, B, C,  5, 12, 0x4787C62A);
+	P(C, D, A, B,  6, 17, 0xA8304613);
+	P(B, C, D, A,  7, 22, 0xFD469501);
+	P(A, B, C, D,  8,  7, 0x698098D8);
+	P(D, A, B, C,  9, 12, 0x8B44F7AF);
+	P(C, D, A, B, 10, 17, 0xFFFF5BB1);
+	P(B, C, D, A, 11, 22, 0x895CD7BE);
+	P(A, B, C, D, 12,  7, 0x6B901122);
+	P(D, A, B, C, 13, 12, 0xFD987193);
+	P(C, D, A, B, 14, 17, 0xA679438E);
+	P(B, C, D, A, 15, 22, 0x49B40821);
+
+#undef F
+
+#define F(x, y, z) (y ^ (z & (x ^ y)))
+
+	P(A, B, C, D,  1,  5, 0xF61E2562);
+	P(D, A, B, C,  6,  9, 0xC040B340);
+	P(C, D, A, B, 11, 14, 0x265E5A51);
+	P(B, C, D, A,  0, 20, 0xE9B6C7AA);
+	P(A, B, C, D,  5,  5, 0xD62F105D);
+	P(D, A, B, C, 10,  9, 0x02441453);
+	P(C, D, A, B, 15, 14, 0xD8A1E681);
+	P(B, C, D, A,  4, 20, 0xE7D3FBC8);
+	P(A, B, C, D,  9,  5, 0x21E1CDE6);
+	P(D, A, B, C, 14,  9, 0xC33707D6);
+	P(C, D, A, B,  3, 14, 0xF4D50D87);
+	P(B, C, D, A,  8, 20, 0x455A14ED);
+	P(A, B, C, D, 13,  5, 0xA9E3E905);
+	P(D, A, B, C,  2,  9, 0xFCEFA3F8);
+	P(C, D, A, B,  7, 14, 0x676F02D9);
+	P(B, C, D, A, 12, 20, 0x8D2A4C8A);
+
+#undef F
+
+#define F(x, y, z) (x ^ y ^ z)
+
+	P(A, B, C, D,  5,  4, 0xFFFA3942);
+	P(D, A, B, C,  8, 11, 0x8771F681);
+	P(C, D, A, B, 11, 16, 0x6D9D6122);
+	P(B, C, D, A, 14, 23, 0xFDE5380C);
+	P(A, B, C, D,  1,  4, 0xA4BEEA44);
+	P(D, A, B, C,  4, 11, 0x4BDECFA9);
+	P(C, D, A, B,  7, 16, 0xF6BB4B60);
+	P(B, C, D, A, 10, 23, 0xBEBFBC70);
+	P(A, B, C, D, 13,  4, 0x289B7EC6);
+	P(D, A, B, C,  0, 11, 0xEAA127FA);
+	P(C, D, A, B,  3, 16, 0xD4EF3085);
+	P(B, C, D, A,  6, 23, 0x04881D05);
+	P(A, B, C, D,  9,  4, 0xD9D4D039);
+	P(D, A, B, C, 12, 11, 0xE6DB99E5);
+	P(C, D, A, B, 15, 16, 0x1FA27CF8);
+	P(B, C, D, A,  2, 23, 0xC4AC5665);
+
+#undef F
+
+#define F(x, y, z) (y ^ (x | ~z))
+
+	P(A, B, C, D,  0,  6, 0xF4292244);
+	P(D, A, B, C,  7, 10, 0x432AFF97);
+	P(C, D, A, B, 14, 15, 0xAB9423A7);
+	P(B, C, D, A,  5, 21, 0xFC93A039);
+	P(A, B, C, D, 12,  6, 0x655B59C3);
+	P(D, A, B, C,  3, 10, 0x8F0CCC92);
+	P(C, D, A, B, 10, 15, 0xFFEFF47D);
+	P(B, C, D, A,  1, 21, 0x85845DD1);
+	P(A, B, C, D,  8,  6, 0x6FA87E4F);
+	P(D, A, B, C, 15, 10, 0xFE2CE6E0);
+	P(C, D, A, B,  6, 15, 0xA3014314);
+	P(B, C, D, A, 13, 21, 0x4E0811A1);
+	P(A, B, C, D,  4,  6, 0xF7537E82);
+	P(D, A, B, C, 11, 10, 0xBD3AF235);
+	P(C, D, A, B,  2, 15, 0x2AD7D2BB);
+	P(B, C, D, A,  9, 21, 0xEB86D391);
+
+#undef F
+
+	ctx->state[0] += A;
+	ctx->state[1] += B;
+	ctx->state[2] += C;
+	ctx->state[3] += D;
+}
+
+void md5_update(md5_context *ctx, const uint8 *input, uint32 length) {
+	uint32 left, fill;
+
+	if (!length)
+		return;
+
+	left = ctx->total[0] & 0x3F;
+	fill = 64 - left;
+
+	ctx->total[0] += length;
+	ctx->total[0] &= 0xFFFFFFFF;
+
+	if (ctx->total[0] < length)
+		ctx->total[1]++;
+
+	if (left && length >= fill) {
+		memcpy((void *)(ctx->buffer + left), (const void *)input, fill);
+		md5_process(ctx, ctx->buffer);
+		length -= fill;
+		input  += fill;
+		left = 0;
+	}
+
+	while (length >= 64) {
+		md5_process(ctx, input);
+		length -= 64;
+		input  += 64;
+	}
+
+	if (length) {
+		memcpy((void *)(ctx->buffer + left), (const void *)input, length);
+	}
+}
+
+static const uint8 md5_padding[64] = {
+	0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
+};
+
+void md5_finish(md5_context *ctx, uint8 digest[16]) {
+	uint32 last, padn;
+	uint32 high, low;
+	uint8 msglen[8];
+
+	high = (ctx->total[0] >> 29) | (ctx->total[1] << 3);
+	low  = (ctx->total[0] <<  3);
+
+	PUT_UINT32(low,  msglen, 0);
+	PUT_UINT32(high, msglen, 4);
+
+	last = ctx->total[0] & 0x3F;
+	padn = (last < 56) ? (56 - last) : (120 - last);
+
+	md5_update(ctx, md5_padding, padn);
+	md5_update(ctx, msglen, 8);
+
+	PUT_UINT32(ctx->state[0], digest,  0);
+	PUT_UINT32(ctx->state[1], digest,  4);
+	PUT_UINT32(ctx->state[2], digest,  8);
+	PUT_UINT32(ctx->state[3], digest, 12);
+}
+
+bool md5_file(const char *name, uint8 digest[16], uint32 length) {
+	FILE *f;
+
+	f = fopen(name, "rb");
+	if (f == NULL) {
+		printf("md5_file couldn't open '%s'\n", name);
+		return false;
+	}
+
+	md5_context ctx;
+	uint32 i;
+	unsigned char buf[1000];
+	bool restricted = (length != 0);
+	int readlen;
+
+	if (!restricted || sizeof(buf) <= length)
+		readlen = sizeof(buf);
+	else
+		readlen = length;
+
+	md5_starts(&ctx);
+
+
+	while ((i = (uint32)fread(buf, 1, readlen, f)) > 0) {
+		md5_update(&ctx, buf, i);
+
+		length -= i;
+		if (restricted && length == 0)
+			break;
+
+		if (restricted && sizeof(buf) > length)
+			readlen = length;
+	}
+
+	md5_finish(&ctx, digest);
+	fclose(f);
+	return true;
+}
+
+void md5_buffer(byte *buf, uint32 len, uint8 digest[16]) {
+	md5_context ctx;
+
+	md5_starts(&ctx);
+	md5_update(&ctx, buf, len);
+	md5_finish(&ctx, digest);
+}
+
diff --git a/devtools/create_neverhood/md5.h b/devtools/create_neverhood/md5.h
new file mode 100644
index 0000000000..81bc03ff83
--- /dev/null
+++ b/devtools/create_neverhood/md5.h
@@ -0,0 +1,41 @@
+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ */
+
+#ifndef COMMON_MD5_H
+#define COMMON_MD5_H
+
+#include "util.h"
+
+typedef struct {
+	uint32 total[2];
+	uint32 state[4];
+	uint8 buffer[64];
+} md5_context;
+
+void md5_starts(md5_context *ctx);
+void md5_update(md5_context *ctx, const uint8 *input, uint32 length);
+void md5_finish(md5_context *ctx, uint8 digest[16]);
+
+bool md5_file(const char *name, uint8 digest[16], uint32 length = 0);
+void md5_buffer(byte *buf, uint32 len, uint8 digest[16]);
+
+#endif
diff --git a/devtools/create_neverhood/module.mk b/devtools/create_neverhood/module.mk
index 284e19105d..8e263559b5 100644
--- a/devtools/create_neverhood/module.mk
+++ b/devtools/create_neverhood/module.mk
@@ -3,6 +3,7 @@ MODULE := devtools/create_neverhood
 
 MODULE_OBJS := \
 	create_neverhood.o \
+	md5.o \
 	util.o
 
 # Set the name of the executable