/* Executable memory regions demo / unit test Copyright(c) 2015 Chris Eagle This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License version 2 as published by the Free Software Foundation. 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. */ #define __STDC_FORMAT_MACROS #include #include #include #include #include #include #include unsigned char PROGRAM[] = "\xeb\x45\x5e\x81\xe6\x00\xf0\xff\xff\x40\x40\x40\x40\x40\x40\x40" "\x40\x40\x40\x40\x40\x40\x40\x40\x40\x40\x40\x40\x40\x40\x40\x40" "\x40\x40\x40\x40\x40\x40\x40\x89\xf7\x81\xc7\x00\x00\x10\x00\xb9" "\x4c\x00\x00\x00\x81\xff\x00\x00\x40\x00\x75\x01\xf4\xf3\xa4\x81" "\xe7\x00\xf0\xff\xff\xff\xe7\xe8\xb6\xff\xff\xff"; // total size: 76 bytes /* bits 32 ; assumes r-x section at 0x100000 ; assumes rw- section at 0x200000 ; assumes r-- section at 0x300000 ; also needs an initialized stack start: jmp bottom top: pop esi and esi, ~0xfff times 30 inc eax mov edi, esi add edi, 0x100000 mov ecx, end - start rep movsb and edi, ~0xfff cmp edi, 0x400000 jnz next_block hlt next_block: jmp edi bottom: call top end: */ int test_num = 0; uint32_t tests[] = { 0x41414141, 0x43434343, 0x45454545 }; static int log_num = 1; #define CODE_SECTION 0x100000 #define CODE_SIZE 0x1000 // callback for tracing instruction static void hook_code(uc_engine *uc, uint64_t addr, uint32_t size, void *user_data) { uint8_t opcode; if (uc_mem_read(uc, addr, &opcode, 1) != UC_ERR_OK) { printf("not ok %d - uc_mem_read fail during hook_code callback, addr: 0x%" PRIx64 "\n", log_num++, addr); } // printf("ok %d - uc_mem_read for opcode at address 0x%" PRIx64 "\n", log_num++, addr); switch (opcode) { case 0xf4: //hlt printf("# Handling HLT\n"); if (uc_emu_stop(uc) != UC_ERR_OK) { printf("not ok %d - uc_emu_stop fail during hook_code callback, addr: 0x%" PRIx64 "\n", log_num++, addr); _exit(-1); } else { printf("ok %d - hlt encountered, uc_emu_stop called\n", log_num++); } break; default: //all others // printf("# Handling OTHER\n"); break; } } // callback for tracing memory access (READ or WRITE) static void hook_mem_write(uc_engine *uc, uc_mem_type type, uint64_t addr, int size, int64_t value, void *user_data) { printf("# write to memory at 0x%"PRIx64 ", data size = %u, data value = 0x%"PRIx64 "\n", addr, size, value); } // callback for tracing invalid memory access (READ or WRITE) static bool hook_mem_invalid(uc_engine *uc, uc_mem_type type, uint64_t addr, int size, int64_t value, void *user_data) { switch(type) { default: printf("not ok %d - UC_HOOK_MEM_INVALID type: %d at 0x%" PRIx64 "\n", log_num++, type, addr); return false; case UC_MEM_EXEC_PROT: printf("# Fetch from non-executable memory at 0x%"PRIx64 "\n", addr); //make page executable if (uc_mem_protect(uc, addr & ~0xfffL, 0x1000, UC_PROT_READ | UC_PROT_EXEC) != UC_ERR_OK) { printf("not ok %d - uc_mem_protect fail for address: 0x%" PRIx64 "\n", log_num++, addr); } else { printf("ok %d - uc_mem_protect success at 0x%" PRIx64 "\n", log_num++, addr); } return true; case UC_MEM_WRITE_PROT: printf("# write to non-writeable memory at 0x%"PRIx64 ", data size = %u, data value = 0x%"PRIx64 "\n", addr, size, value); if (uc_mem_protect(uc, addr & ~0xfffL, 0x1000, UC_PROT_READ | UC_PROT_WRITE) != UC_ERR_OK) { printf("not ok %d - uc_mem_protect fail during hook_mem_invalid callback, addr: 0x%" PRIx64 "\n", log_num++, addr); } else { printf("ok %d - uc_mem_protect success\n", log_num++); } return true; } } int main(int argc, char **argv, char **envp) { uc_engine *uc; uc_hook trace1, trace2; uc_err err; uint32_t esp, eip; int32_t buf1[1024], buf2[1024], readbuf[1024]; int i; //don't really care about quality of randomness srand(time(NULL)); for (i = 0; i < 1024; i++) { buf1[i] = rand(); buf2[i] = rand(); } printf("# Memory protect test\n"); // Initialize emulator in X86-32bit mode err = uc_open(UC_ARCH_X86, UC_MODE_32, &uc); if (err) { printf("not ok %d - Failed on uc_open() with error returned: %u\n", log_num++, err); return 1; } else { printf("ok %d - uc_open() success\n", log_num++); } uc_mem_map(uc, 0x100000, 0x1000, UC_PROT_READ | UC_PROT_EXEC); uc_mem_map(uc, 0x1ff000, 0x2000, UC_PROT_READ | UC_PROT_WRITE); uc_mem_map(uc, 0x300000, 0x2000, UC_PROT_READ); uc_mem_map(uc, 0xf00000, 0x1000, UC_PROT_READ | UC_PROT_WRITE); esp = 0xf00000 + 0x1000; // Setup stack pointer if (uc_reg_write(uc, UC_X86_REG_ESP, &esp)) { printf("not ok %d - Failed to set esp. quit!\n", log_num++); return 2; } else { printf("ok %d - ESP set\n", log_num++); } // fill in sections that shouldn't get touched if (uc_mem_write(uc, 0x1ff000, buf1, sizeof(buf1))) { printf("not ok %d - Failed to write random buffer 1 to memory, quit!\n", log_num++); return 3; } else { printf("ok %d - Random buffer 1 written to memory\n", log_num++); } if (uc_mem_write(uc, 0x301000, buf2, sizeof(buf2))) { printf("not ok %d - Failed to write random buffer 2 to memory, quit!\n", log_num++); return 4; } else { printf("ok %d - Random buffer 2 written to memory\n", log_num++); } // write machine code to be emulated to memory if (uc_mem_write(uc, 0x100000, PROGRAM, sizeof(PROGRAM))) { printf("not ok %d - Failed to write emulation code to memory, quit!\n", log_num++); return 5; } else { printf("ok %d - Program written to memory\n", log_num++); } if (uc_hook_add(uc, &trace2, UC_HOOK_CODE, hook_code, NULL, (uint64_t)1, (uint64_t)0) != UC_ERR_OK) { printf("not ok %d - Failed to install UC_HOOK_CODE ucr\n", log_num++); return 6; } else { printf("ok %d - UC_HOOK_CODE installed\n", log_num++); } // intercept memory write events if (uc_hook_add(uc, &trace1, UC_HOOK_MEM_WRITE, hook_mem_write, NULL, (uint64_t)1, (uint64_t)0) != UC_ERR_OK) { printf("not ok %d - Failed to install UC_HOOK_MEM_WRITE ucr\n", log_num++); return 7; } else { printf("ok %d - UC_HOOK_MEM_WRITE installed\n", log_num++); } // intercept invalid memory events if (uc_hook_add(uc, &trace1, UC_HOOK_MEM_INVALID, hook_mem_invalid, NULL) != UC_ERR_OK) { printf("not ok %d - Failed to install UC_HOOK_MEM_INVALID ucr\n", log_num++); return 8; } else { printf("ok %d - UC_HOOK_MEM_INVALID installed\n", log_num++); } // emulate machine code until told to stop by hook_code printf("# BEGIN execution\n"); err = uc_emu_start(uc, 0x100000, 0x400000, 0, 0); if (err != UC_ERR_OK) { printf("not ok %d - Failure on uc_emu_start() with error %u:%s\n", log_num++, err, uc_strerror(err)); return 9; } else { printf("ok %d - uc_emu_start complete\n", log_num++); } printf("# END execution\n"); // get ending EIP if (uc_reg_read(uc, UC_X86_REG_EIP, &eip)) { printf("not ok %d - Failed to read eip.\n", log_num++); } else { printf("ok %d - Ending EIP 0x%x\n", log_num++, eip); } //make sure that random blocks didn't get nuked // fill in sections that shouldn't get touched if (uc_mem_read(uc, 0x1ff000, readbuf, sizeof(readbuf))) { printf("not ok %d - Failed to read random buffer 1 from memory\n", log_num++); } else { printf("ok %d - Random buffer 1 read from memory\n", log_num++); if (memcmp(buf1, readbuf, 4096)) { printf("not ok %d - Random buffer 1 contents are incorrect\n", log_num++); } else { printf("ok %d - Random buffer 1 contents are correct\n", log_num++); } } if (uc_mem_read(uc, 0x301000, readbuf, sizeof(readbuf))) { printf("not ok %d - Failed to read random buffer 2 from memory\n", log_num++); } else { printf("ok %d - Random buffer 2 read from memory\n", log_num++); if (memcmp(buf2, readbuf, 4096)) { printf("not ok %d - Random buffer 2 contents are incorrect\n", log_num++); } else { printf("ok %d - Random buffer 2 contents are correct\n", log_num++); } } if (uc_close(uc) == UC_ERR_OK) { printf("ok %d - uc_close complete\n", log_num++); } else { printf("not ok %d - uc_close complete\n", log_num++); } return 0; }