compiler_archs: Add PowerPC

Author: shaymargolis

shellblocks/compiler_archs/__init__.py

@@ -4,6 +4,7 @@
 from shellblocks.compiler_archs.arm import CompilerArchARMLE
 from shellblocks.compiler_archs.x86 import CompilerArchX86
 from shellblocks.compiler_archs.x86_64 import CompilerArchX86_64
+from shellblocks.compiler_archs.powerpc import CompilerArchPowerPC
 from shellblocks.compiler_arch import CompilerArch
 
 
@@ -13,6 +14,7 @@ class CompilerArchOption(Enum):
     ARMLE = "armle"
     X86 = "x86"
     X86_64 = "x86_64"
+    POWERPC = "powerpc"
 
 
 def get_current_platform():
@@ -33,6 +35,8 @@ def get_current_platform():
         return CompilerArchOption.ARMLE
     if "x86_64-" in machine:
         return CompilerArchOption.X86_64
+    if "powerpc64le-" in machine:
+        return CompilerArchOption.POWERPC
 
     return None
 
@@ -51,6 +55,8 @@ def compiler_arch_to_object(arch: CompilerArchOption) -> CompilerArch:
         return CompilerArchX86(CompilerArchOption.X86_64 == current_platform)
     elif arch == CompilerArchOption.X86_64:
         return CompilerArchX86_64(use_main_gcc)
+    elif arch == CompilerArchOption.POWERPC:
+        return CompilerArchPowerPC(use_main_gcc)
 
     raise NotImplementedError()
 

shellblocks/compiler_archs/powerpc.py

@@ -0,0 +1,24 @@
+from typing import List
+
+from shellblocks.compiler_archs.gcc import CompilerArchGCC
+from shellblocks.utils import sources_location
+
+
+class CompilerArchPowerPC(CompilerArchGCC):
+    def __init__(self, use_main_gcc: bool):
+        super().__init__(use_main_gcc)
+
+    def get_gcc_flags(self):
+        return super().get_gcc_flags() + [
+            "-m32",
+            "-mbig",
+        ]
+
+    def get_headers(self) -> List[str]:
+        return ["arch/powerpc/utils.h"]
+
+    def get_ldscript_path(self):
+        return (sources_location / "shellcode_ldscript.ld").as_posix()
+
+    def get_compiler_path(self):
+        return "powerpc64le-linux-gnu-gcc-10"

shellblocks/src/arch/powerpc/utils.h

@@ -0,0 +1,15 @@
+#ifndef SHELLCODE_BLOCKS_ARCH_POWERPC_UTILS_H
+#define SHELLCODE_BLOCKS_ARCH_POWERPC_UTILS_H
+
+#define NOP_OPCODE (0x60000000)
+
+#define GET_REL_ADDRESS(OUTPUT, LABEL)                              \
+    __asm__ volatile (                                              \
+        "bl " GET_REL_LABEL(LABEL) "\n\t"                           \
+        "nop\n\t"                                                   \
+        GET_REL_LABEL(LABEL) ": mr %0, 8\n\t"                       \
+        "addis %0, %0, (" #LABEL " - " GET_REL_LABEL(LABEL) ")\n\t" \
+        : "=r" (OUTPUT) : : "8"                                     \
+    )
+
+#endif // !SHELLCODE_BLOCKS_ARCH_POWERPC_UTILS_H

shellblocks/src/arch/utils.h

@@ -7,6 +7,8 @@
 #include "x86/utils.h"
 #elif defined(__arm__)
 #include "arm/utils.h"
+#elif defined(__powerpc__)
+#include "powerpc/utils.h"
 #endif
 
 #define REL_ACCESS_STRING __attribute__((section(".text")))

shellblocks/test_arch_helper.py

@@ -1,6 +1,7 @@
 from unicorn.mips_const import UC_MIPS_REG_PC, UC_MIPS_REG_29, UC_MIPS_REG_4
 from unicorn.arm_const import UC_ARM_REG_PC, UC_ARM_REG_SP, UC_ARM_REG_R0
 from unicorn.x86_const import UC_X86_REG_EIP, UC_X86_REG_ESP, UC_X86_REG_RDI
+from unicorn.ppc_const import UC_PPC_REG_PC, UC_PPC_REG_1, UC_PPC_REG_3
 
 from shellblocks.compiler_archs import CompilerArchOption
 
@@ -58,6 +59,34 @@ def get_curr_func_arg(self, mu, func_arg):
         )
 
 
+class PowerPCHelper(ArchHelper):
+    def __init__(self, compiler_arch_option):
+        super().__init__(compiler_arch_option)
+
+        assert compiler_arch_option in [
+            CompilerArchOption.POWERPC,
+        ]
+
+    def get_ret_bytes(self):
+        val = 0x4E800020
+        return val.to_bytes(4, 'little')
+
+    def get_curr_pc(self, mu):
+        return mu.reg_read(UC_PPC_REG_PC)
+
+    def set_curr_sp(self, mu, new_stack):
+        mu.reg_write(UC_PPC_REG_1, new_stack)
+
+    def get_curr_sp(self, mu):
+        return mu.reg_read(UC_PPC_REG_1)
+
+    def get_curr_func_arg(self, mu, func_arg):
+        if func_arg == 0:
+            return mu.reg_read(UC_PPC_REG_3)
+
+        raise NotImplementedError(f"Getting {func_arg} func arg")
+
+
 class ARMHelper(ArchHelper):
     def __init__(self, compiler_arch_option):
         super().__init__(compiler_arch_option)

tests/conftest.py

@@ -10,14 +10,16 @@
     UC_ARCH_ARM,
     UC_ARCH_X86,
     UC_MODE_ARM,
+    UC_ARCH_PPC,
     UC_MODE_32,
     UC_MODE_64,
     UC_MODE_BIG_ENDIAN,
     UC_MODE_LITTLE_ENDIAN,
+    UC_MODE_PPC32,
 )
 
 
-from shellblocks.test_arch_helper import MIPSHelper, ARMHelper, X86Helper
+from shellblocks.test_arch_helper import MIPSHelper, ARMHelper, X86Helper, PowerPCHelper
 
 from shellblocks.compiler_archs import CompilerArchOption, compiler_arch_to_object
 
@@ -52,6 +54,8 @@ def arch_helper(compiler_arch_option):
         return ARMHelper(compiler_arch_option)
     if compiler_arch_option in [CompilerArchOption.X86, CompilerArchOption.X86_64]:
         return X86Helper(compiler_arch_option)
+    if compiler_arch_option in [CompilerArchOption.POWERPC]:
+        return PowerPCHelper(compiler_arch_option)
     else:
         raise NotImplementedError("Arch unimplemented error!")
 
@@ -69,6 +73,8 @@ def get_mu_instance():
             return Uc(UC_ARCH_X86, UC_MODE_32)
         elif CompilerArchOption.X86_64 == compiler_arch_option:
             return Uc(UC_ARCH_X86, UC_MODE_64)
+        elif CompilerArchOption.POWERPC == compiler_arch_option:
+            return Uc(UC_ARCH_PPC, UC_MODE_PPC32 | UC_MODE_BIG_ENDIAN)
         else:
             raise NotImplementedError("Arch unimplemented error!")