Minor docs update. Trying to dump memory

.gitignore

@@ -1,5 +1,6 @@
 dump/
 *.bin
 *.a
+venv/
 reven/
 !dump/exynos-usbdl/

documentation/source/BootROM_8890/boot_chain.rst

@@ -1,6 +1,8 @@
+.. _boot-chain-label:
 =======
 Booting
 =======
+
 After exploitation the goal is to fully boot the device.
 
 Current boot chain:

documentation/source/BootROM_8890/index.rst

@@ -15,12 +15,40 @@ Samsung Firmware
 ----------------
 Samsung releases firmware files for their devices. These files contain the bootloader, modem, and other firmware files.
 To see how the ROM works we are interested in the sboot firmware, which contains multiple stages of the bootloader.
+
 To extract the sboot.bin file from a samsung firmware file:
 
 .. code-block:: bash
 
    $ unzip -p firmware.zip 'BL_*.tar.md5' | tar -Oxf - 'sboot.bin.lz4' | lz4 -d - sboot.bin
 
+Frederic has also written a payload to extract the sboot.bin file from a connected samsung device (See: :ref:`boot-chain-label`). The extracted boots can be split up in different stages. We're provied with sboot 1-4.bin. Running strings then provides us with some information about each stage.
+
+.. code-block:: bash
+
+	$ strings -n4 sboot.bin.1.bin
+
+was
+
+.. list-table:: bootrom stages
+	:header-rows: 1
+
+	* - File
+	  - Strings output
+	  - Likely boot stage?
+	* - sboot.bin.1.bin
+	  - Exynos BL1
+	  - BL1
+	* - sboot.bin.2.bin
+	  - BL31 %s
+	  - BL31
+	* - sboot.bin.3.bin
+	  - Unsure. Contains strings like: TOP_DIV_ACLK_MFC_600 and APOLLO_DIV_APOLLO_RUN_MONITOR
+	  - BL2?
+	* - sboot.bin.4.bin
+	  - Contains more textual information, and references to post BL2 boot, and android information
+	  - Kernel boot/BL33?
+
 Memory Layout
 -------------
 TODO make memory layout of ROM, IMEM and some devices @JONHE

reven/SamsungS7.lock

@@ -1,9 +1,9 @@
 #Ghidra Lock File
-#Tue Aug 06 19:30:30 CEST 2024
+#Fri Aug 09 11:27:43 CEST 2024
 OS\ Name=Linux
 OS\ Version=6.5.0-44-generic
 Username=eljakim
 Hostname=levith
 <META>\ Supports\ File\ Channel\ Locking=Channel Lock
 OS\ Architecture=amd64
-Timestamp=8/6/24, 7\:30 PM
+Timestamp=8/9/24, 11\:27 AM

source/exploit/.vscode/launch.json

@@ -10,7 +10,7 @@
             "request": "launch",
             "program": "exploit.py",
             "console": "integratedTerminal",
-            "args": ["--usb-debug"]
+            "args": ["--debug"]
         },
         {
             "name": "Run boot chain",
@@ -19,15 +19,6 @@
             "program": "exploit.py",
             "console": "integratedTerminal",
             "justMyCode": false,
-            "args": ["--run-boot-chain"]
-        },
-        {
-            "name": "Debug on device",
-            "type": "debugpy",
-            "request": "launch",
-            "program": "exploit.py",
-            "console": "integratedTerminal",
-            "justMyCode": false,
             "args": []
         },
         {

source/exploit/exploit.py

@@ -5,7 +5,7 @@ from ghidra_assistant.utils.utils import *
 from ghidra_assistant.concrete_device import *
 from ghidra_assistant.utils.debugger.debugger_archs.ga_arm64 import GA_arm64_debugger
 from qiling.const import QL_ARCH
-import os
+import os, tqdm, datetime
 
 def p32(x):
     return struct.pack("<I", x)
@@ -56,7 +56,6 @@ class ExynosDevice():
         self.target = "8890"  # TODO auto detect device
         self.connect_device()
 
-
     def connect_device(self):
         """Setup proper connection, and ensure the connection is alive"""
         self.context = usb1.USBContext()
@@ -81,13 +80,11 @@ class ExynosDevice():
                 raise e
         print(f"Connected device! {hex(self.idVendor)} {hex(self.idProduct)}")
 
-
     def write(self, data):
         transferred = ctypes.c_int()
         res = libusb1.libusb_bulk_transfer(self.handle._USBDeviceHandle__handle, ENDPOINT_BULK_OUT, data, len(data), ctypes.byref(transferred), 0)
         assert(res == 0), "Could not perform bulk transfer"
         return res
-    
 
     def send_empty_transfer(self):
         transferred = ctypes.c_int()
@@ -95,7 +92,6 @@ class ExynosDevice():
         assert(res == 0)
         return transferred.value
     
-    
     def test_bug_2(self):
         """Interger overflow in last packet if reamining size is 1."""
         transferred = ctypes.c_int()
@@ -113,7 +109,6 @@ class ExynosDevice():
         while True:
             res = libusb1.libusb_bulk_transfer(self.handle._USBDeviceHandle__handle, ENDPOINT_BULK_OUT, payload, len(payload), ctypes.byref(transferred), 10)
 
-
     def test_bug(self):
         # Start by sending a valid packet
         # Integer overflow in the size field
@@ -141,7 +136,6 @@ class ExynosDevice():
         assert res == 0, "Error sending payload"
         pass
 
-
     def exploit(self, payload: bytes):
         '''
         Exploit the Exynos device, payload of 502 bytes max. This will send stage1 payload. 
@@ -227,10 +221,9 @@ class ExynosDevice():
         #Overwrite all calls to make the concrete target function properly
         concrete_device.copy_functions()
 
-    
     def usb_debug(self):
         """
-        Function to debug USB behaviour
+        Function to debug USB behaviour. Sends and receives data in continuous flow.
         """
         transferred = ctypes.c_int()
         # Send some data
@@ -254,85 +247,36 @@ class ExynosDevice():
             _recv_data()
             count += 1
 
-        
-    def dumb_interact(self):
-        '''
-        Room for playing around with the debugger
-        '''
-        self.cd.arch_dbg.state.auto_sync = False
-        self.cd.arch_dbg.state.print_ctx()
-        
-        # Overwrite jump back
-        # self.cd.memwrite_region(0x02020108, p32(0x2069000))
-        # self.cd.memwrite_region(0x02021800, p32(0x2069000))
-        self.cd.memwrite_region(0x020200e8, p32(0x02069000)) # address, data. Writes 
-        
-        AUTH_BL1 = 0x00012848
-        def memdump_try():
-            self.cd.arch_dbg.state.LR = 0x020200e8
-            self.cd.restore_stack_and_jump(0x02021810)
-            stack_pointer = 0x02021810
-            dumped = b""
-            for block in range(0x2020000, 0x2200000, 0x200):
-                stack_pointer += 0x200
-                self.cd.arch_dbg.state.print_ctx()
-                print(hex(block))
-                dumped += self.cd.memdump_region(block, 0x200)
-                if stack_pointer >= 0x02020F08:
-                    print(f'stack_pointer at {stack_pointer}')
-            return dumped
-                
-        def auth_bl1():
-            # Load the firmware
-            self.cd.arch_dbg.state.X0 = 1
-            self.cd.arch_dbg.state.X1 = 1
-            self.cd.arch_dbg.state.LR = 0x2069000 #jump back to debugger when finished
-            self.cd.restore_stack_and_jump(AUTH_BL1)
-            
-        def jump_bl1():
-            self.cd.arch_dbg.state.LR = 0x2069000
-            self.cd.restore_stack_and_jump(0x02024010)
-            # self.cd.restore_stack_and_jump(0x02021810)
-            
-        #000125b4
-        # self.cd.arch_dbg.state.LR = 0x2069000 #jump back to debugger when finished
-        # self.cd.restore_stack_and_jump(0x00012814)
-        # self.cd.restore_stack_and_jump(0x000125b4)
+    def dump_memory(self, start: hex=0x0, end: hex=0x0206ffff, write=False):
+        """
+        Dumps memory from the device.
 
-        dumped = memdump_try()
+        Transfer XFER_BUFFER at 0x02021800, to: 0x02020F08. End of memory at 0x0206ffff.
+        """
+        # NOT WORKING YET
+        transferred = ctypes.c_int()
+        dumped = b""
+        # Read data from memory
+        for block in tqdm.tqdm(range(start, end, 0x200)):
+            self.usb_write(p32(block-0x200))
+            res = self.usb_read(0x200)
+            dumped += res
         
-        bl1 = open("../S7/bl1.bin", "rb").read()
-        self.cd.memwrite_region(0x02024000, bl1)
-        self.usb_write(b"FLSH")
-        
-        # auth_bl1()
-        jump_bl1()
-        assert self.usb_read(0x200) == b"GiAs", "not jumped back to debugger?"
-        self.cd.arch_dbg.state.print_ctx()
-        
-        def jump_bl31():
-            self.cd.arch_dbg.state.LR = 0x2069000
-            self.cd.restore_stack_and_jump(0x02021810)
-        bl31 = open("../S7/bl31.bin", "rb").read()
+        if write:
+            filename = f"dump_{hex(start)}_{hex(end)}_{self.target}_{datetime.datetime.now().strftime('%Y-%m-%d_%H-%M-%S')}.bin"
+            with open(filename, "wb") as f:
+                f.write(dumped)
+        return dumped
 
-        self.cd.memwrite_region(0x02021800, bl31)
-        jump_bl31()
-        assert self.usb_read(0x200) == b"GiAs", "not jumped back to debugger?"
-        self.cd.arch_dbg.state.print_ctx()
-        
-        # memdump_try()
-        # auth_bl1()
-        self.cd.arch_dbg.state.print_ctx()
-        
-        #authenticate it
-        pass
-    
+        # transferred = ctypes.c_int()
+        # stack_pointer = 0x02021810
+        # for block in range(0x2020000, 0x2200000, 0x200):
+        #     stack_pointer += 0x200
+        #     dumped += self.cd.memdump_region(block, 0x200)
 
     def setup_guppy_debugger(self):
         """
-        Run the boot chain for the Exynos device.
-
-        Load and send stage1 payload - exploit (stage1)
+        Sets up guppy debugger on the device itself.
         """
             
         def _setup_debugger():
@@ -368,26 +312,124 @@ class ExynosDevice():
         
         _initial_run_debugger()
         _setup_debugger()
+        
+    def dumb_interact(self):
+        '''
+        Room for playing around with the debugger
+        '''
+        self.cd.arch_dbg.state.auto_sync = False
+        self.cd.arch_dbg.state.auto_sync_special = False
+        self.cd.arch_dbg.state.print_ctx()
+        
+        def relocate_debugger():
+            # Seems to be cleared upon cache clearing??
+            if os.getenv("USER") == "eljakim":
+                debugger_reloc = open("/home/eljakim/Source/gupje/source/bin/samsung_s7/debugger.bin", "rb").read()
+            else:
+                try:
+                    debugger_reloc = open("../../dump/debugger.bin", "rb").read()
+                except Exception as e:
+                    print(f'Are you missing your debugger? Please ensure it is present in dump/debugger.bin. {e}')
+                    sys.exit(0)
+            self.cd.memwrite_region(0x020c0000, debugger_reloc)
+            self.usb_write(b"FLSH") # Flush cache
+            self.cd.restore_stack_and_jump(0x020c0000)
+            assert self.usb_read(0x200) == b"GiAs", "Failed to relocate debugger"
+            self.cd.relocate_debugger(0x020c7000, 0x020c0000, 0x020c4000)
+        relocate_debugger()
+        
+        # Try loading bl1
+        bl1 = open("../S7/bl1.bin", "rb").read()
+        self.cd.memwrite_region(0x02021800, bl1)
+        # self.usb_write(b"FLSH")
+        AUTH_BL1 = 0x00012848
+        def auth_bl1(lr=0x2069000):
+            # Load the firmware
+            self.cd.arch_dbg.state.W0 = 1
+            self.cd.arch_dbg.state.X1 = 1
+            self.cd.arch_dbg.state.LR = lr #jump back to debugger when finished
+            self.cd.restore_stack_and_jump(AUTH_BL1)
+            assert self.usb_read(0x200) == b"GiAs", "Failed to jump back to debugger"
+            
+        auth_bl1(0x020c0000)
+        
+        # Works until here
+        
+        pass
+        
+        
+        
+        # Overwrite jump back
+        self.cd.memwrite_region(0x02020108, p32(0x2069000))
+        self.cd.memwrite_region(0x020200e8, p32(0x2069000))
+        
+        def memdump_try():
+            self.cd.arch_dbg.state.LR = 0x020200e8
+            self.cd.restore_stack_and_jump(0x02021810)
+            stack_pointer = 0x02021810
+            dumped = b""
+            for block in range(0x2020000, 0x2200000, 0x200):
+                stack_pointer += 0x200
+                self.cd.arch_dbg.state.print_ctx()
+                print(hex(block))
+                dumped += self.cd.memdump_region(block, 0x200)
+                
+        
+            
+        def jump_bl1():
+            self.cd.arch_dbg.state.LR = 0x2069000
+            self.cd.restore_stack_and_jump(0x02024010)
+            # self.cd.restore_stack_and_jump(0x02021810)
+            
+        #000125b4
+        # self.cd.arch_dbg.state.LR = 0x2069000 #jump back to debugger when finished
+        # self.cd.restore_stack_and_jump(0x00012814)
+        # self.cd.restore_stack_and_jump(0x000125b4)
+        
+        
+        
+        auth_bl1()
+        
+        # auth_bl1()
+        jump_bl1()
+        assert self.usb_read(0x200) == b"GiAs", "not jumped back to debugger?"
+        self.cd.arch_dbg.state.print_ctx()
+        
+        def jump_bl31():
+            self.cd.arch_dbg.state.LR = 0x2069000
+            self.cd.restore_stack_and_jump(0x02021810)
+        bl31 = open("../S7/bl31.bin", "rb").read()
+
+        self.cd.memwrite_region(0x02021800, bl31)
+        jump_bl31()
+        assert self.usb_read(0x200) == b"GiAs", "not jumped back to debugger?"
+        self.cd.arch_dbg.state.print_ctx()
+        
+        # memdump_try()
+        # auth_bl1()
+        self.cd.arch_dbg.state.print_ctx()
+        
+        #authenticate it
+        pass
 
 
 if __name__ == "__main__":
     arg = argparse.ArgumentParser("Exynos exploit")
-    arg.add_argument("--usb-debug", action="store_true", help="Debug USB stack", default=False)
-    arg.add_argument("--run-boot-chain", action="store_true", help="Run boot chain to boot different boot stages", default=False)
-    arg.add_argument("--dumb-debug", action="store_true", help="Live debugging on device", default=True)
+    arg.add_argument("--debug", action="store_true", help="Debug USB stack", default=False)
     args = arg.parse_args()
     
     exynos = ExynosDevice()
 
-    if args.usb_debug:
+    if args.debug:
         shellcode = open("../dwc3_test/dwc3.bin", "rb").read()
         exynos.exploit(shellcode)
-        exynos.usb_debug()
+        exynos.dump_memory(write=True)
+        # exynos.usb_debug()
+        sys.exit(0)
 
-    elif args.run_boot_chain:
-        stage1 = open("stage1/stage1.bin", "rb").read()
-        exynos.exploit(stage1)
-        exynos.setup_guppy_debugger()
-        exynos.dumb_interact()
+    stage1 = open("stage1/stage1.bin", "rb").read()
+    exynos.exploit(stage1)
+    exynos.setup_guppy_debugger()
+    exynos.dumb_interact()
         
     sys.exit(0)

source/gupje_device/Makefile

@@ -8,10 +8,21 @@ OBJCOPY := $(ANDROID_NDK_ROOT)/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64
 LD := $(ANDROID_NDK_ROOT)/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android-ld.bfd
 
 #==================Target Samsung S7 (8890)==================
+all: samsung_s7 samsung_s7_reloc
+
 CFLAGS_SAMSUNGS7 = -Os -Idevices/samsung_s7/
 samsung_s7:
 	[ -d bin/samsung_s7 ] || mkdir -p bin/samsung_s7/
 	$(CC) arm64_stub.S -c -o bin/samsung_s7/entry.o $(CFLAGS_SAMSUNGS7)
 	$(CC) debugger.c -c -o bin/samsung_s7/debugger.o $(CFLAGS_SAMSUNGS7)
 	$(LD) -T devices/samsung_s7/linkscript.ld bin/samsung_s7/entry.o bin/samsung_s7/debugger.o -o bin/samsung_s7/debugger.elf --just-symbols=devices/samsung_s7/symbols.txt
-	$(OBJCOPY) -O binary bin/samsung_s7/debugger.elf bin/samsung_s7/debugger.bin
+	$(OBJCOPY) -O binary bin/samsung_s7/debugger.elf bin/samsung_s7/debugger.bin
+
+CFLAGS_SAMSUNGS7_RELOC = -Os -DRELOC_DEBUGGER=1 -Idevices/samsung_s7/ 
+samsung_s7_reloc:
+	[ -d bin/samsung_s7 ] || mkdir -p bin/samsung_s7/
+	$(CC) arm64_stub.S -c -o bin/samsung_s7/reloc_entry.o $(CFLAGS_SAMSUNGS7_RELOC)
+	$(CC) debugger.c -c -o bin/samsung_s7/reloc_debugger.o $(CFLAGS_SAMSUNGS7_RELOC)
+	$(LD) -T devices/samsung_s7/reloc_linkscript.ld bin/samsung_s7/reloc_entry.o bin/samsung_s7/reloc_debugger.o -o bin/samsung_s7/reloc_debugger.elf --just-symbols=devices/samsung_s7/reloc_symbols.txt
+	$(OBJCOPY) -O binary bin/samsung_s7/reloc_debugger.elf bin/samsung_s7/reloc_debugger.bin
+

source/gupje_device/Readme.md

@@ -1,8 +1,14 @@
 # Gupje
 Current memory map:
 
+## Stage 2
+Memory map in stage2 after exploitation
 ![memory map](memory_map.drawio.svg)
 
+## Stage 3
+Memory map in stage3 after relocating the debugger
+
+
 ## Usage:
 Copy this folder to <gupje>/devices/samsung_s7 and run:
 

source/gupje_device/device.h

@@ -8,6 +8,8 @@ extern int usb_event_handler(void);
 extern uint32_t get_endpoint_recv_buffer(char endpoint);
 extern void exynos_sleep(int endpoint,uint32_t timeout);
 extern void usb_send(uint32_t address,uint32_t size);
+extern uint32_t recv_buffer;
+extern uint32_t data_received;
 
 int mystrlen(char *data) {
     int i=0;
@@ -19,9 +21,13 @@ int mystrlen(char *data) {
     return i-1;
 }
 
-
+#ifdef RELOC_DEBUGGER
+#define recv_buffer 0x020c6200 
+#define data_received 0x020c6000
+#else
 #define recv_buffer 0x206fe00 //0x02021800 + 0x3000
 #define data_received 0x206fd00
+#endif
 
 void recv_data_cb(uint32_t endpoint, uint32_t len){
     char *dest_buf = (char *)recv_buffer;

source/gupje_device/reloc_linkscript.ld

@@ -0,0 +1,14 @@
+MEMORY {
+    ROM (rwx): ORIGIN = 0x020c0000, LENGTH = 0x1000
+}
+
+SECTIONS
+{
+     . = 0x020c0000;
+     .text . : {
+          *(.text*)
+          *(.data*)
+          *(.rodata*)
+     } >ROM
+
+}

source/gupje_device/reloc_symbols.txt

@@ -0,0 +1,12 @@
+debugger_storage = 0x020c4000;
+debugger_stack = 0x020c2000;
+debugger_entry = 0x020c0000;
+
+maybe_usb_setup_read = 0x00006f88;
+dwc3_ep0_start_trans = 0x0000791c;
+usb_event_handler = 0x00007bac;
+get_endpoint_recv_buffer = 0x00007a7c;
+exynos_sleep = 0x000027c8;
+
+g_recv_buffer = 0x020c6200;
+g_data_received = 0x020c6000;

source/gupje_device/symbols.txt

@@ -6,4 +6,6 @@ maybe_usb_setup_read = 0x00006f88;
 dwc3_ep0_start_trans = 0x0000791c;
 usb_event_handler = 0x00007bac;
 get_endpoint_recv_buffer = 0x00007a7c;
-exynos_sleep = 0x000027c8;
+exynos_sleep = 0x000027c8;
+
+RELOCATED = 0;