1 files changed, 157 insertions, 394 deletions

@@ -1,4 +1,5 @@
 /*
+ * Copyright (c) 2017 slipstream/RoL
  * Copyright (C) 2016 FIX94
  *
  * This software may be modified and distributed under the terms
@@ -13,8 +14,6 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
-#include <dirent.h>
-#include <fat.h>
 
 //from my tests 50us seems to be the lowest
 //safe si transfer delay in between calls
@@ -27,9 +26,8 @@ void printmain()
 {
         printf("\x1b[2J");
         printf("\x1b[37m");
-        printf("GBA Link Cable Dumper v1.6 by FIX94\n");
-        printf("Save Support based on SendSave by Chishm\n");
-        printf("GBA BIOS Dumper by Dark Fader\n \n");
+        printf("Pokemon Gen 3 GBA Multiboot PoC by slipstream/RoL\n");
+        printf("Based on GBA Link Cable Dumper by FIX94\n\n");
 }
 
 u8 *resbuf,*cmdbuf;
@@ -46,21 +44,17 @@ void acb(s32 res, u32 val)
         resval = val;
 }
 
-unsigned int docrc(u32 crc, u32 val)
-{
-        int i;
-        for(i = 0; i < 0x20; i++)
-        {
-                if((crc^val)&1)
-                {
-                        crc>>=1;
-                        crc^=0xa1c1;
-                }
-                else
-                        crc>>=1;
-                val>>=1;
+unsigned int docrc(u32 crc,u32 val) {
+        u32 result;
+        
+        result = val ^ crc;
+        for (int i = 0; i < 0x20; i++) {
+                if (result & 1) {
+                        result >>= 1;
+                        result ^= 0xA1C1;
+                } else result >>= 1;
         }
-        return crc;
+        return result;
 }
 
 void endproc()
@@ -70,64 +64,7 @@ void endproc()
         VIDEO_WaitVSync();
         exit(0);
 }
-void fixFName(char *str)
-{
-        u8 i = 0;
-        for(i = 0; i < strlen(str); ++i)
-        {
-                if(str[i] < 0x20 || str[i] > 0x7F)
-                        str[i] = '_';
-                else switch(str[i])
-                {
-                        case '\\':
-                        case '/':
-                        case ':':
-                        case '*':
-                        case '?':
-                        case '\"':
-                        case '<':
-                        case '>':
-                        case '|':
-                                str[i] = '_';
-                                break;
-                        default:
-                                break;
-                }
-        }
-}
-unsigned int calckey(unsigned int size)
-{
-        unsigned int ret = 0;
-        size=(size-0x200) >> 3;
-        int res1 = (size&0x3F80) << 1;
-        res1 |= (size&0x4000) << 2;
-        res1 |= (size&0x7F);
-        res1 |= 0x380000;
-        int res2 = res1;
-        res1 = res2 >> 0x10;
-        int res3 = res2 >> 8;
-        res3 += res1;
-        res3 += res2;
-        res3 <<= 24;
-        res3 |= res2;
-        res3 |= 0x80808080;
 
-        if((res3&0x200) == 0)
-        {
-                ret |= (((res3)&0xFF)^0x4B)<<24;
-                ret |= (((res3>>8)&0xFF)^0x61)<<16;
-                ret |= (((res3>>16)&0xFF)^0x77)<<8;
-                ret |= (((res3>>24)&0xFF)^0x61);
-        }
-        else
-        {
-                ret |= (((res3)&0xFF)^0x73)<<24;
-                ret |= (((res3>>8)&0xFF)^0x65)<<16;
-                ret |= (((res3>>16)&0xFF)^0x64)<<8;
-                ret |= (((res3>>24)&0xFF)^0x6F);
-        }
-        return ret;
-}
 void doreset()
 {
         cmdbuf[0] = 0xFF; //reset
@@ -135,6 +72,7 @@ void doreset()
         SI_Transfer(1,cmdbuf,1,resbuf,3,transcb,SI_TRANS_DELAY);
         while(transval == 0) ;
 }
+
 void getstatus()
 {
         cmdbuf[0] = 0; //status
@@ -142,6 +80,7 @@ void getstatus()
         SI_Transfer(1,cmdbuf,1,resbuf,3,transcb,SI_TRANS_DELAY);
         while(transval == 0) ;
 }
+
 u32 recv()
 {
         memset(resbuf,0,32);
@@ -151,6 +90,7 @@ u32 recv()
         while(transval == 0) ;
         return *(vu32*)resbuf;
 }
+
 void send(u32 msg)
 {
         cmdbuf[0]=0x15;cmdbuf[1]=(msg>>0)&0xFF;cmdbuf[2]=(msg>>8)&0xFF;
@@ -160,26 +100,7 @@ void send(u32 msg)
         SI_Transfer(1,cmdbuf,5,resbuf,1,transcb,SI_TRANS_DELAY);
         while(transval == 0) ;
 }
-bool dirExists(const char *path)
-{
-        DIR *dir;
-        dir = opendir(path);
-        if(dir)
-        {
-                closedir(dir);
-                return true;
-        }
-        return false;
-}
-void createFile(const char *path, size_t size)
-{
-        int fd = open(path, O_WRONLY|O_CREAT);
-        if(fd >= 0)
-        {
-                ftruncate(fd, size);
-                close(fd);
-        }
-}
+
 void warnError(char *msg)
 {
         puts(msg);
@@ -195,6 +116,68 @@ void fatalError(char *msg)
         sleep(5);
         exit(0);
 }
+
+u32 genKeyA() {
+        u32 retries = 0;
+        while (true) {
+                u32 key = 0;
+                if (retries > 32) {
+                        key = 0xDD654321;
+                } else {
+                        key = (rand() & 0x00ffffff) | 0xDD000000;
+                }
+                u32 unk = (key % 2 != 0);
+                u32 v12 = key;
+                for (u32 v13 = 1; v13 < 32; v13++) {
+                        v12 >>= 1;
+                        unk += (v12 % 2 != 0);
+                }
+                if ((unk >= 10 && unk <= 24)) {
+                        if (retries > 4) printf("KeyA retries = %d",retries);
+                        printf("KeyA = 0x%08x\n",key);
+                        return key;
+                }
+                retries++;
+        }
+}
+
+u32 checkKeyB(u32 KeyBRaw) {
+        if ((KeyBRaw & 0xFF) != 0xEE) {
+                printf("Invalid KeyB - lowest 8 bits should be 0xEE, actually 0x%02x\n",((u8)(KeyBRaw)));
+                return 0;
+        }
+        u32 KeyB = KeyBRaw & 0xffffff00;
+        u32 val = KeyB;
+        u32 unk = (val < 0);
+        for (u32 i = 1; i < 24; i++) {
+                val <<= 1;
+                unk += (val < 0);
+        }
+        if (unk > 14) {
+                printf("Invalid KeyB - high 24 bits bad: 0x%08x\n",KeyB);
+                return 0;
+        }
+        printf("Valid KeyB: 0x%08x\n",KeyB);
+        return KeyB;
+}
+
+u32 deriveKeyC(u32 keyCderive, u32 kcrc) {
+        u32 keyc = 0;
+        u32 keyCi = 0;
+        do {
+                u32 v5 = 0x1000000 * keyCi - 1;
+                u32 keyCattempt = docrc(kcrc,v5);
+                //printf("i = %d; keyCderive = %08x; keyCattempt = %08x\n",keyCi,keyCderive,keyCattempt);
+                if (keyCderive == keyCattempt) {
+                        keyc = v5;
+                        printf("Found keyC: %08x\n",keyc);
+                        return keyc;
+                }
+                keyCi++;
+        } while (keyCi < 256);
+        return keyc;
+}
+
 int main(int argc, char *argv[]) 
 {
         void *xfb = NULL;
@@ -216,19 +199,6 @@ int main(int argc, char *argv[])
         PAD_Init();
         cmdbuf = memalign(32,32);
         resbuf = memalign(32,32);
-        u8 *testdump = memalign(32,0x400000);
-        if(!testdump) return 0;
-        if(!fatInitDefault())
-        {
-                printmain();
-                fatalError("ERROR: No usable device found to write dumped files to!");
-        }
-        mkdir("/dumps", S_IREAD | S_IWRITE);
-        if(!dirExists("/dumps"))
-        {
-                printmain();
-                fatalError("ERROR: Could not create dumps folder, make sure you have a supported device connected!");
-        }
         int i;
         while(1)
         {
@@ -251,305 +221,98 @@ int main(int argc, char *argv[])
                         }
                         PAD_ScanPads();
                         VIDEO_WaitVSync();
-                        if(PAD_ButtonsHeld(0))
+                        if(PAD_ButtonsDown(0) & PAD_BUTTON_START)
                                 endproc();
                 }
-                if(resval & SI_GBA)
+                if (resval & SI_GBA)
                 {
                         printf("GBA Found! Waiting on BIOS\n");
                         resbuf[2]=0;
-                        while(!(resbuf[2]&0x10))
+                        u32 oldresult = 0;
+                        u32 newresult = 0;
+                        // wait for the BIOS to hand over to the game
+                        do {
+                                doreset();
+                        } while (!(resbuf[1] > 4));
+                        printf("BIOS handed over to game, waiting on game\n");
+                        do
                         {
                                 doreset();
-                                getstatus();
-                        }
-                        printf("Ready, sending dumper\n");
+                        } while((resbuf[0] != 0) || !(resbuf[2]&0x10));
+                        // receive the game-code from GBA side.
+                        u32 gamecode = recv();
+                        printf("Ready, sending multiboot ROM\n");
                         unsigned int sendsize = ((gba_mb_gba_size+7)&~7);
-                        unsigned int ourkey = calckey(sendsize);
+                        // generate KeyA
+                        unsigned int ourkey = genKeyA();
                         //printf("Our Key: %08x\n", ourkey);
-                        //get current sessionkey
-                        u32 sessionkeyraw = recv();
-                        u32 sessionkey = __builtin_bswap32(sessionkeyraw^0x7365646F);
-                        //send over our own key
-                        send(__builtin_bswap32(ourkey));
-                        unsigned int fcrc = 0x15a0;
-                        //send over gba header
-                        for(i = 0; i < 0xC0; i+=4)
-                                send(__builtin_bswap32(*(vu32*)(gba_mb_gba+i)));
-                        //printf("Header done! Sending ROM...\n");
-                        for(i = 0xC0; i < sendsize; i+=4)
+                        printf("Sending game code that we got: 0x%08x\n",__builtin_bswap32(gamecode));
+                        // send the game code back, then KeyA.
+                        send(__builtin_bswap32(gamecode));
+                        send(ourkey);
+                        // get KeyB from GBA, check it to make sure its valid, then xor with KeyA to derive the initial CRC value and the sessionkey.
+                        u32 sessionkeyraw = 0;
+                        do {
+                                sessionkeyraw = recv();
+                        } while (sessionkeyraw == gamecode);
+                        sessionkeyraw = checkKeyB(__builtin_bswap32(sessionkeyraw));
+                        u32 sessionkey = sessionkeyraw ^ ourkey;
+                        u32 kcrc = sessionkey;
+                        printf("start kCRC=%08x\n",kcrc);
+                        sessionkey = (sessionkey*0x6177614b)+1;
+                        // send hacked up send-size in uint32s
+                        u32 hackedupsize = (sendsize >> 3) - 1;
+                        printf("Sending hacked up size 0x%08x\n",hackedupsize);
+                        send(hackedupsize);
+                        //unsigned int fcrc = 0x00bb;
+                        // send over multiboot binary header, in the clear until the end of the nintendo logo.
+                        // GBA checks this, if nintendo logo does not match the one in currently inserted cart's ROM, it will not accept any more data.
+                        for(i = 0; i < 0xA0; i+=4) {
+                                vu32 rom_dword = *(vu32*)(gba_mb_gba+i);
+                                send(__builtin_bswap32(rom_dword));
+                        }
+                        printf("\n");
+                        printf("Header done! Sending ROM...\n");
+                        // Add each uint32 of the multiboot image to the checksum, encrypt the uint32 with the session key, increment the session key, send the encrypted uint32.
+                        for(i = 0xA0; i < sendsize; i+=4)
                         {
-                                u32 enc = ((gba_mb_gba[i+3]<<24)|(gba_mb_gba[i+2]<<16)|(gba_mb_gba[i+1]<<8)|(gba_mb_gba[i]));
-                                fcrc=docrc(fcrc,enc);
+                                u32 dec = (
+                                        ((gba_mb_gba[i+3]) << 24) & 0xff000000 |
+                                        ((gba_mb_gba[i+2]) << 16) & 0x00ff0000 |
+                                        ((gba_mb_gba[i+1]) << 8)  & 0x0000ff00 |
+                                        ((gba_mb_gba[i])   << 0)  & 0x000000ff
+                                );
+                                u32 enc = (dec - kcrc) ^ sessionkey;
+                                kcrc=docrc(kcrc,dec);
                                 sessionkey = (sessionkey*0x6177614B)+1;
-                                enc^=sessionkey;
-                                enc^=((~(i+(0x20<<20)))+1);
-                                enc^=0x20796220;
+                                //enc^=((~(i+(0x20<<20)))+1);
+                                //enc^=0x6f646573;//0x20796220;
                                 send(enc);
                         }
-                        fcrc |= (sendsize<<16);
-                        //printf("ROM done! CRC: %08x\n", fcrc);
-                        //send over CRC
-                        sessionkey = (sessionkey*0x6177614B)+1;
-                        fcrc^=sessionkey;
-                        fcrc^=((~(i+(0x20<<20)))+1);
-                        fcrc^=0x20796220;
-                        send(fcrc);
+                        //fcrc |= (sendsize<<16);
+                        printf("ROM done! CRC: %08x\n", kcrc);
                         //get crc back (unused)
-                        recv();
-                        printf("Done!\n");
-                        sleep(2);
-                        //hm
-                        while(1)
-                        {
-                                printmain();
-                                printf("Press A once you have a GBA Game inserted.\n");
-                                printf("Press Y to backup the GBA BIOS.\n \n");
-                                PAD_ScanPads();
-                                VIDEO_WaitVSync();
-                                u32 btns = PAD_ButtonsDown(0);
-                                if(btns&PAD_BUTTON_START)
-                                        endproc();
-                                else if(btns&PAD_BUTTON_A)
-                                {
-                                        if(recv() == 0) //ready
-                                        {
-                                                printf("Waiting for GBA\n");
-                                                VIDEO_WaitVSync();
-                                                int gbasize = 0;
-                                                while(gbasize == 0)
-                                                        gbasize = __builtin_bswap32(recv());
-                                                send(0); //got gbasize
-                                                u32 savesize = __builtin_bswap32(recv());
-                                                send(0); //got savesize
-                                                if(gbasize == -1) 
-                                                {
-                                                        warnError("ERROR: No (Valid) GBA Card inserted!\n");
-                                                        continue;
-                                                }
-                                                //get rom header
-                                                for(i = 0; i < 0xC0; i+=4)
-                                                        *(vu32*)(testdump+i) = recv();
-                                                //print out all the info from the  game
-                                                printf("Game Name: %.12s\n",(char*)(testdump+0xA0));
-                                                printf("Game ID: %.4s\n",(char*)(testdump+0xAC));
-                                                printf("Company ID: %.2s\n",(char*)(testdump+0xB0));
-                                                printf("ROM Size: %02.02f MB\n",((float)(gbasize/1024))/1024.f);
-                                                if(savesize > 0)
-                                                        printf("Save Size: %02.02f KB\n \n",((float)(savesize))/1024.f);
-                                                else
-                                                        printf("No Save File\n \n");
-                                                //generate file paths
-                                                char gamename[64];
-                                                sprintf(gamename,"/dumps/%.12s [%.4s%.2s].gba",
-                                                        (char*)(testdump+0xA0),(char*)(testdump+0xAC),(char*)(testdump+0xB0));
-                                                fixFName(gamename+7); //fix name behind "/dumps/"
-                                                char savename[64];
-                                                sprintf(savename,"/dumps/%.12s [%.4s%.2s].sav",
-                                                        (char*)(testdump+0xA0),(char*)(testdump+0xAC),(char*)(testdump+0xB0));
-                                                fixFName(savename+7); //fix name behind "/dumps/"
-                                                //let the user choose the option
-                                                printf("Press A to dump this game, it will take about %i minutes.\n",gbasize/1024/1024*3/2);
-                                                printf("Press B if you want to cancel dumping this game.\n");
-                                                if(savesize > 0)
-                                                {
-                                                        printf("Press Y to backup this save file.\n");
-                                                        printf("Press X to restore this save file.\n");
-                                                        printf("Press Z to clear the save file on the GBA Cartridge.\n\n");
-                                                }
-                                                else
-                                                        printf("\n");
-                                                int command = 0;
-                                                while(1)
-                                                {
-                                                        PAD_ScanPads();
-                                                        VIDEO_WaitVSync();
-                                                        u32 btns = PAD_ButtonsDown(0);
-                                                        if(btns&PAD_BUTTON_START)
-                                                                endproc();
-                                                        else if(btns&PAD_BUTTON_A)
-                                                        {
-                                                                command = 1;
-                                                                break;
-                                                        }
-                                                        else if(btns&PAD_BUTTON_B)
-                                                                break;
-                                                        else if(savesize > 0)
-                                                        {
-                                                                if(btns&PAD_BUTTON_Y)
-                                                                {
-                                                                        command = 2;
-                                                                        break;
-                                                                }
-                                                                else if(btns&PAD_BUTTON_X)
-                                                                {
-                                                                        command = 3;
-                                                                        break;
-                                                                }
-                                                                else if(btns&PAD_TRIGGER_Z)
-                                                                {
-                                                                        command = 4;
-                                                                        break;
-                                                                }
-                                                        }
-                                                }
-                                                if(command == 1)
-                                                {
-                                                        FILE *f = fopen(gamename,"rb");
-                                                        if(f)
-                                                        {
-                                                                fclose(f);
-                                                                command = 0;
-                                                                warnError("ERROR: Game already dumped!\n");
-                                                        }
-                                                }
-                                                else if(command == 2)
-                                                {
-                                                        FILE *f = fopen(savename,"rb");
-                                                        if(f)
-                                                        {
-                                                                fclose(f);
-                                                                command = 0;
-                                                                warnError("ERROR: Save already backed up!\n");
-                                                        }
-                                                }
-                                                else if(command == 3)
-                                                {
-                                                        size_t readsize = 0;
-                                                        FILE *f = fopen(savename,"rb");
-                                                        if(f)
-                                                        {
-                                                                fseek(f,0,SEEK_END);
-                                                                readsize = ftell(f);
-                                                                if(readsize != savesize)
-                                                                {
-                                                                        command = 0;
-                                                                        warnError("ERROR: Save has the wrong size, aborting restore!\n");
-                                                                }
-                                                                else
-                                                                {
-                                                                        rewind(f);
-                                                                        fread(testdump,readsize,1,f);
-                                                                }
-                                                                fclose(f);
-                                                        }
-                                                        else
-                                                        {
-                                                                command = 0;
-                                                                warnError("ERROR: No Save to restore!\n");
-                                                        }
-                                                }
-                                                send(command);
-                                                //let gba prepare
-                                                sleep(1);
-                                                if(command == 0)
-                                                        continue;
-                                                else if(command == 1)
-                                                {
-                                                        //create base file with size
-                                                        printf("Preparing file...\n");
-                                                        createFile(gamename,gbasize);
-                                                        FILE *f = fopen(gamename,"wb");
-                                                        if(!f)
-                                                                fatalError("ERROR: Could not create file! Exit...");
-                                                        printf("Dumping...\n");
-                                                        u32 bytes_read = 0;
-                                                        while(gbasize > 0)
-                                                        {
-                                                                int toread = (gbasize > 0x400000 ? 0x400000 : gbasize);
-                                                                int j;
-                                                                for(j = 0; j < toread; j+=4)
-                                                                {
-                                                                        *(vu32*)(testdump+j) = recv();
-                                                                        bytes_read+=4;
-                                                                        if((bytes_read&0xFFFF) == 0)
-                                                                                printf("\r%02.02f MB done",(float)(bytes_read/1024)/1024.f);
-                                                                }
-                                                                fwrite(testdump,toread,1,f);
-                                                                gbasize -= toread;
-                                                        }
-                                                        printf("\nClosing file\n");
-                                                        fclose(f);
-                                                        printf("Game dumped!\n");
-                                                        sleep(5);
-                                                }
-                                                else if(command == 2)
-                                                {
-                                                        //create base file with size
-                                                        printf("Preparing file...\n");
-                                                        createFile(savename,savesize);
-                                                        FILE *f = fopen(savename,"wb");
-                                                        if(!f)
-                                                                fatalError("ERROR: Could not create file! Exit...");
-                                                        printf("Waiting for GBA\n");
-                                                        VIDEO_WaitVSync();
-                                                        u32 readval = 0;
-                                                        while(readval != savesize)
-                                                                readval = __builtin_bswap32(recv());
-                                                        send(0); //got savesize
-                                                        printf("Receiving...\n");
-                                                        for(i = 0; i < savesize; i+=4)
-                                                                *(vu32*)(testdump+i) = recv();
-                                                        printf("Writing save...\n");
-                                                        fwrite(testdump,savesize,1,f);
-                                                        fclose(f);
-                                                        printf("Save backed up!\n");
-                                                        sleep(5);
-                                                }
-                                                else if(command == 3 || command == 4)
-                                                {
-                                                        u32 readval = 0;
-                                                        while(readval != savesize)
-                                                                readval = __builtin_bswap32(recv());
-                                                        if(command == 3)
-                                                        {
-                                                                printf("Sending save\n");
-                                                                VIDEO_WaitVSync();
-                                                                for(i = 0; i < savesize; i+=4)
-                                                                        send(__builtin_bswap32(*(vu32*)(testdump+i)));
-                                                        }
-                                                        printf("Waiting for GBA\n");
-                                                        while(recv() != 0)
-                                                                VIDEO_WaitVSync();
-                                                        printf(command == 3 ? "Save restored!\n" : "Save cleared!\n");
-                                                        send(0);
-                                                        sleep(5);
-                                                }
-                                        }
-                                }
-                                else if(btns&PAD_BUTTON_Y)
-                                {
-                                        const char *biosname = "/dumps/gba_bios.bin";
-                                        FILE *f = fopen(biosname,"rb");
-                                        if(f)
-                                        {
-                                                fclose(f);
-                                                warnError("ERROR: BIOS already backed up!\n");
-                                        }
-                                        else
-                                        {
-                                                //create base file with size
-                                                printf("Preparing file...\n");
-                                                createFile(biosname,0x4000);
-                                                f = fopen(biosname,"wb");
-                                                if(!f)
-                                                        fatalError("ERROR: Could not create file! Exit...");
-                                                //send over bios dump command
-                                                send(5);
-                                                //the gba might still be in a loop itself
-                                                sleep(1);
-                                                //lets go!
-                                                printf("Dumping...\n");
-                                                for(i = 0; i < 0x4000; i+=4)
-                                                        *(vu32*)(testdump+i) = recv();
-                                                fwrite(testdump,0x4000,1,f);
-                                                printf("Closing file\n");
-                                                fclose(f);
-                                                printf("BIOS dumped!\n");
-                                                sleep(5);
-                                        }
-                                }
-                        }
+                        // Get KeyC derivation material from GBA (eventually)
+                        u32 keyCderive = 0;
+                        do {
+                                keyCderive = recv();
+                        } while (keyCderive <= 0xfeffffff);
+                        keyCderive = __builtin_bswap32(keyCderive);
+                        keyCderive >>= 8;
+                        printf("KeyC derivation material: %08x\n",keyCderive);
+                        
+                        // (try to) find the KeyC, using the checksum of the multiboot image, and the derivation material that GBA sent to us
+                        
+                        u32 keyc = deriveKeyC(keyCderive,kcrc);
+                        if (keyc == 0) printf("Could not find keyC - kcrc=0x%08x\n",kcrc);
+                        
+                        // derive the boot key from the found KeyC, and send to GBA. if this is not correct, GBA will not jump to the multiboot image it was sent. 
+                        u32 bootkey = docrc(0xBB,keyc) | 0xbb000000;
+                        printf("BootKey = 0x%08x\n",bootkey);
+                        send(bootkey);
+                        
+                        printf("Done! Press any key to start sending again.\n");
+                        do { PAD_ScanPads(); } while (!PAD_ButtonsDown(0));
                 }
         }
         return 0;