概述
我们平时所说的代码注入,主要静态和动态两种方式:
静态注入,针对是可执行文件,比如修改ELF,DEX文件等,相关的辅助工具也很多,比如IDA、ApkTool等;
动态注入,也可以叫进程注入,针对是进程,比如修改进程的寄存器、内存值等;
动态跟静态最大的区别是,动态不需要改动源文件,但需要高权限(通常是root权限),而且所需的技术含量更高。
基本思路
关键点在于让目标进加载自定义的动态库so,当so被加载后,so就可以加载其他模块、dex文件等,
具体的注入过程大致如下:
1) attach上目标进程;
2) 让目标进程的执行流程跳转到mmap函数来分配内存空间;
3) 加载注入so;
4) 最后让目标进程的执行流程跳转到注入的代码执行。让目标进程跳转到注入so中的代码执行。
参考:
http://ele7enxxh.com/Android-Shared-Library-Injection.html
http://ele7enxxh.com/Android-Shared-Library-Hook-With-GOT.html
//获取目标进程模块基址
void* get_module_base(pid_t pid, const char* module_name);
//获取远程模块基址
void* get_remote_addr(pid_t target_pid, const char* module_name, void* local_addr);
//根据进程名查找进程id 读取/proc/%d/cmdline获取进程名
int find_pid_of(const char *process_name);
//root inject注入远程进程流程
首先挂载到目标进程 ptrace_attach(target_pid)
读取目标进程寄存器数据 ptrace_getregs(target_pid, ®s)
保存原来的寄存器数据 memcpy(&original_regs, ®s, sizeof(regs));
获取目标进程mmap函数的地址,get_remote_addr(target_pid, libc_path, (void *)mmap);
在目标进程中调用mmap函数,来分配内存空间; ptrace_call_wrapper(target_pid, "mmap", mmap_addr, parameters, 6, ®s)
获取目标进程 dlopen 函数的地址 get_remote_addr( target_pid, linker_path, (void *)dlopen );
获取目标进程 dlsym 函数的地址 get_remote_addr( target_pid, linker_path, (void *)dlsym );
获取目标进程 dlclose 函数的地址 get_remote_addr( target_pid, linker_path, (void *)dlclose );
获取目标进程 dlerror 函数的地址 get_remote_addr( target_pid, linker_path, (void *)dlerror );
往目标进程写入library_path数据 ptrace_writedata(target_pid, map_base, library_path, strlen(library_path) + 1);
让目标进程调用 dlopen 函数 (ptrace_call_wrapper(target_pid, "dlopen", dlopen_addr, parameters, 2, ®s)
让目标进程调用 dlsym 函数 ptrace_call_wrapper(target_pid, "dlsym", dlsym_addr, parameters, 2, ®s)
让目标进程调用 hook_entry 函数 ptrace_call_wrapper(target_pid, function_name, hook_entry_addr, parameters, 1, ®s)
让目标进程调用 dlclose 函数 ptrace_call_wrapper(target_pid, "dlclose", dlclose, parameters, 1, ®s)
恢复寄存器
ptrace_setregs(target_pid, &original_regs);
从目标进程中卸载
ptrace_detach(target_pid);
#include <stdio.h> #include <stdlib.h> #include <asm/user.h> #include <asm/ptrace.h> #include <sys/ptrace.h> #include <sys/wait.h> #include <sys/mman.h> #include <dlfcn.h> #include <dirent.h> #include <unistd.h> #include <string.h> #include <elf.h> #include <android/log.h> #if defined(__i386__) #define pt_regs user_regs_struct #endif #define ENABLE_DEBUG 1 #if ENABLE_DEBUG #define LOG_TAG "inject" #define LOGD(fmt, args...) __android_log_print(ANDROID_LOG_ERROR,LOG_TAG, fmt, ##args) #define DEBUG_PRINT(format,args...) LOGD(format, ##args) #else #define DEBUG_PRINT(format,args...) #endif #define CPSR_T_MASK ( 1u << 5 ) const char *libc_path = "/system/lib/libc.so"; const char *linker_path = "/system/bin/linker"; //读取进程数据 int ptrace_readdata(pid_t pid, uint8_t *src, uint8_t *buf, size_t size) { uint32_t i, j, remain; uint8_t *laddr; union u { long val; char chars[sizeof(long)]; } d; j = size / 4; remain = size % 4; laddr = buf; for (i = 0; i < j; i ++) { //拷贝src指向的数据 d.val = ptrace(PTRACE_PEEKTEXT, pid, src, 0); memcpy(laddr, d.chars, 4); src += 4; laddr += 4; } if (remain > 0) { d.val = ptrace(PTRACE_PEEKTEXT, pid, src, 0); memcpy(laddr, d.chars, remain); } return 0; } //往进程写入数据 int ptrace_writedata(pid_t pid, uint8_t *dest, uint8_t *data, size_t size) { uint32_t i, j, remain; uint8_t *laddr; union u { long val; char chars[sizeof(long)]; } d; j = size / 4; remain = size % 4; laddr = data; for (i = 0; i < j; i ++) { memcpy(d.chars, laddr, 4); ptrace(PTRACE_POKETEXT, pid, dest, d.val); dest += 4; laddr += 4; } if (remain > 0) { d.val = ptrace(PTRACE_PEEKTEXT, pid, dest, 0); for (i = 0; i < remain; i ++) { d.chars[i] = *laddr ++; } ptrace(PTRACE_POKETEXT, pid, dest, d.val); } return 0; } #if defined(__arm__) int ptrace_call(pid_t pid, uint32_t addr, long *params, uint32_t num_params, struct pt_regs* regs) { uint32_t i; for (i = 0; i < num_params && i < 4; i ++) { regs->uregs[i] = params[i]; } // // push remained params onto stack // if (i < num_params) { regs->ARM_sp -= (num_params - i) * sizeof(long) ; ptrace_writedata(pid, (void *)regs->ARM_sp, (uint8_t *)¶ms[i], (num_params - i) * sizeof(long)); } regs->ARM_pc = addr; if (regs->ARM_pc & 1) { /* thumb */ regs->ARM_pc &= (~1u); regs->ARM_cpsr |= CPSR_T_MASK; } else { /* arm */ regs->ARM_cpsr &= ~CPSR_T_MASK; } regs->ARM_lr = 0; if (ptrace_setregs(pid, regs) == -1 || ptrace_continue(pid) == -1) { printf("error\n"); return -1; } int stat = 0; waitpid(pid, &stat, WUNTRACED); while (stat != 0xb7f) { if (ptrace_continue(pid) == -1) { printf("error\n"); return -1; } waitpid(pid, &stat, WUNTRACED); } return 0; } #elif defined(__i386__) long ptrace_call(pid_t pid, uint32_t addr, long *params, uint32_t num_params, struct user_regs_struct * regs) { regs->esp -= (num_params) * sizeof(long) ; ptrace_writedata(pid, (void *)regs->esp, (uint8_t *)params, (num_params) * sizeof(long)); long tmp_addr = 0x00; regs->esp -= sizeof(long); ptrace_writedata(pid, regs->esp, (char *)&tmp_addr, sizeof(tmp_addr)); regs->eip = addr; if (ptrace_setregs(pid, regs) == -1 || ptrace_continue( pid) == -1) { printf("error\n"); return -1; } int stat = 0; waitpid(pid, &stat, WUNTRACED); while (stat != 0xb7f) { if (ptrace_continue(pid) == -1) { printf("error\n"); return -1; } waitpid(pid, &stat, WUNTRACED); } return 0; } #else #error "Not supported" #endif //读取进程寄存器数据 int ptrace_getregs(pid_t pid, struct pt_regs * regs) { if (ptrace(PTRACE_GETREGS, pid, NULL, regs) < 0) { perror("ptrace_getregs: Can not get register values"); return -1; } return 0; } //设置进程寄存器 int ptrace_setregs(pid_t pid, struct pt_regs * regs) { if (ptrace(PTRACE_SETREGS, pid, NULL, regs) < 0) { perror("ptrace_setregs: Can not set register values"); return -1; } return 0; } //进程继续指向 int ptrace_continue(pid_t pid) { if (ptrace(PTRACE_CONT, pid, NULL, 0) < 0) { perror("ptrace_cont"); return -1; } return 0; } //挂载到目标进程 int ptrace_attach(pid_t pid) { if (ptrace(PTRACE_ATTACH, pid, NULL, 0) < 0) { perror("ptrace_attach"); return -1; } int status = 0; waitpid(pid, &status , WUNTRACED); return 0; } //从目标进程中卸载 int ptrace_detach(pid_t pid) { if (ptrace(PTRACE_DETACH, pid, NULL, 0) < 0) { perror("ptrace_detach"); return -1; } return 0; } //获取目标进程模块基址 void* get_module_base(pid_t pid, const char* module_name) { FILE *fp; long addr = 0; char *pch; char filename[32]; char line[1024]; if (pid < 0) { /* self process */ snprintf(filename, sizeof(filename), "/proc/self/maps", pid); } else { snprintf(filename, sizeof(filename), "/proc/%d/maps", pid); } fp = fopen(filename, "r"); if (fp != NULL) { while (fgets(line, sizeof(line), fp)) { if (strstr(line, module_name)) { pch = strtok( line, "-" ); addr = strtoul( pch, NULL, 16 ); if (addr == 0x8000) addr = 0; break; } } fclose(fp) ; } return (void *)addr; } //获取远程模块基址 void* get_remote_addr(pid_t target_pid, const char* module_name, void* local_addr) { void* local_handle, *remote_handle; local_handle = get_module_base(-1, module_name); remote_handle = get_module_base(target_pid, module_name); DEBUG_PRINT("[+] get_remote_addr: local[%x], remote[%x]\n", local_handle, remote_handle); void * ret_addr = (void *)((uint32_t)local_addr + (uint32_t)remote_handle - (uint32_t)local_handle); #if defined(__i386__) if (!strcmp(module_name, libc_path)) { ret_addr += 2; } #endif return ret_addr; } //根据进程名查找进程id 读取/proc/%d/cmdline获取进程名 int find_pid_of(const char *process_name) { int id; pid_t pid = -1; DIR* dir; FILE *fp; char filename[32]; char cmdline[256]; struct dirent * entry; if (process_name == NULL) return -1; dir = opendir("/proc"); if (dir == NULL) return -1; while((entry = readdir(dir)) != NULL) { id = atoi(entry->d_name); if (id != 0) { sprintf(filename, "/proc/%d/cmdline", id); fp = fopen(filename, "r"); if (fp) { fgets(cmdline, sizeof(cmdline), fp); fclose(fp); if (strcmp(process_name, cmdline) == 0) { /* process found */ pid = id; break; } } } } closedir(dir); return pid; } long ptrace_retval(struct pt_regs * regs) { #if defined(__arm__) return regs->ARM_r0; #elif defined(__i386__) return regs->eax; #else #error "Not supported" #endif } long ptrace_ip(struct pt_regs * regs) { #if defined(__arm__) return regs->ARM_pc; #elif defined(__i386__) return regs->eip; #else #error "Not supported" #endif } int ptrace_call_wrapper(pid_t target_pid, const char * func_name, void * func_addr, long * parameters, int param_num, struct pt_regs * regs) { DEBUG_PRINT("[+] Calling %s in target process.\n", func_name); if (ptrace_call(target_pid, (uint32_t)func_addr, parameters, param_num, regs) == -1) return -1; if (ptrace_getregs(target_pid, regs) == -1) return -1; DEBUG_PRINT("[+] Target process returned from %s, return value=%x, pc=%x \n", func_name, ptrace_retval(regs), ptrace_ip(regs)); return 0; } //注入远程进程数据 int inject_remote_process(pid_t target_pid, const char *library_path, const char *function_name, const char *param, size_t param_size) { int ret = -1; void *mmap_addr, *dlopen_addr, *dlsym_addr, *dlclose_addr, *dlerror_addr; void *local_handle, *remote_handle, *dlhandle; uint8_t *map_base = 0; uint8_t *dlopen_param1_ptr, *dlsym_param2_ptr, *saved_r0_pc_ptr, *inject_param_ptr, *remote_code_ptr, *local_code_ptr; struct pt_regs regs, original_regs; extern uint32_t _dlopen_addr_s, _dlopen_param1_s, _dlopen_param2_s, _dlsym_addr_s, _dlsym_param2_s, _dlclose_addr_s, _inject_start_s, _inject_end_s, _inject_function_param_s, _saved_cpsr_s, _saved_r0_pc_s; uint32_t code_length; long parameters[10]; DEBUG_PRINT("[+] Injecting process: %d\n", target_pid); //首先挂载到目标进程 if (ptrace_attach(target_pid) == -1) goto exit; //读取目标进程寄存器数据 if (ptrace_getregs(target_pid, ®s) == -1) goto exit; /* save original registers 保存原来的寄存器数据*/ memcpy(&original_regs, ®s, sizeof(regs)); //获取目标进程mmap函数的地址 mmap_addr = get_remote_addr(target_pid, libc_path, (void *)mmap); DEBUG_PRINT("[+] Remote mmap address: %x\n", mmap_addr); /* call mmap */ parameters[0] = 0; // addr parameters[1] = 0x4000; // size parameters[2] = PROT_READ | PROT_WRITE | PROT_EXEC; // prot parameters[3] = MAP_ANONYMOUS | MAP_PRIVATE; // flags parameters[4] = 0; //fd parameters[5] = 0; //offset //在目标进程中调用mmap函数 if (ptrace_call_wrapper(target_pid, "mmap", mmap_addr, parameters, 6, ®s) == -1) goto exit; map_base = ptrace_retval(®s); //获取目标进程 dlopen 函数的地址 dlopen_addr = get_remote_addr( target_pid, linker_path, (void *)dlopen ); //获取目标进程 dlsym 函数的地址 dlsym_addr = get_remote_addr( target_pid, linker_path, (void *)dlsym ); //获取目标进程 dlclose 函数的地址 dlclose_addr = get_remote_addr( target_pid, linker_path, (void *)dlclose ); //获取目标进程 dlerror 函数的地址 dlerror_addr = get_remote_addr( target_pid, linker_path, (void *)dlerror ); DEBUG_PRINT("[+] Get imports: dlopen: %x, dlsym: %x, dlclose: %x, dlerror: %x\n", dlopen_addr, dlsym_addr, dlclose_addr, dlerror_addr); printf("library path = %s\n", library_path); //往目标进程写入library_path数据 ptrace_writedata(target_pid, map_base, library_path, strlen(library_path) + 1); parameters[0] = map_base; parameters[1] = RTLD_NOW| RTLD_GLOBAL; //让目标进程调用 dlopen 函数 if (ptrace_call_wrapper(target_pid, "dlopen", dlopen_addr, parameters, 2, ®s) == -1) goto exit; void * sohandle = ptrace_retval(®s); #define FUNCTION_NAME_ADDR_OFFSET 0x100 ptrace_writedata(target_pid, map_base + FUNCTION_NAME_ADDR_OFFSET, function_name, strlen(function_name) + 1); parameters[0] = sohandle; parameters[1] = map_base + FUNCTION_NAME_ADDR_OFFSET; //让目标进程调用 dlsym 函数 if (ptrace_call_wrapper(target_pid, "dlsym", dlsym_addr, parameters, 2, ®s) == -1) goto exit; void * hook_entry_addr = ptrace_retval(®s); DEBUG_PRINT("hook_entry_addr = %p\n", hook_entry_addr); #define FUNCTION_PARAM_ADDR_OFFSET 0x200 ptrace_writedata(target_pid, map_base + FUNCTION_PARAM_ADDR_OFFSET, param, strlen(param) + 1); parameters[0] = map_base + FUNCTION_PARAM_ADDR_OFFSET; ////让目标进程调用 hook_entry 函数 if (ptrace_call_wrapper(target_pid, function_name, hook_entry_addr, parameters, 1, ®s) == -1) goto exit; printf("Press enter to dlclose and detach\n"); //getchar(); parameters[0] = sohandle; // if (ptrace_call_wrapper(target_pid, "dlclose", dlclose, parameters, 1, ®s) == -1) // goto exit; /* restore 恢复寄存器*/ ptrace_setregs(target_pid, &original_regs); //卸载目标进程 ptrace_detach(target_pid); ret = 0; exit: return ret; } int main(int argc, char** argv) { pid_t target_pid; target_pid = find_pid_of("com.estoty.game2048");//also can pass target pid or target process by param if (-1 == target_pid) { printf("Can't find the process\n"); return -1; } printf("target_pid=%d argc=%d\n ",target_pid,argc); char* sopath="/data/local/tmp/libpackage.so"; if(argc>1) { sopath=argv[1]; } char* main_entry="main_entry"; if(argc>2) { main_entry=argv[2]; } char* parameter="parameter"; if(argc>3) { parameter=argv[3]; } printf("inject_remote_process start\n"); inject_remote_process(target_pid, sopath, main_entry, parameter, strlen(parameter)); return 0; }
注入目标进程,执行注入代码
1.attach上目标进程
ptrace_attach(target_pid)
2.获取目标进程寄存器,并复制一份保存,以便在注入完成后恢复目标进程
ptrace_getregs(target_pid, ®s)
3.取目标进程mmap函数地址
get_remote_func_address(target_pid, libc_path, (void *) mmap);
4.调用目标进程mmap函数分配一块内存
ptrace_call_wrapper(target_pid, "mmap", target_mmap_addr, parameters, 6, ®s)
得到mmap分配的内存地址
uint8_t *target_mmap_base = ptrace_retval(®s);
5.调用目标进程dlopen函数加载注入so
取目标进程dlopen函数地址
get_remote_func_address(target_pid, linker_path, (void *) dlopen);
把注入so地址写入目标进程
ptrace_writedata(target_pid, target_mmap_base, library_path,strlen(library_path) + 1);
//通过ptrace调用函数
(ptrace_call_wrapper(target_pid, "dlopen", target_dlopen_addr, parameters, 2,®s)
6.调用dlsym取注入so库执行函数的地址
取目标进程dlsym函数的地址
get_remote_func_address(target_pid, linker_path, (void *) dlsym);
//把函数名称字符串写进目标进程
ptrace_writedata(target_pid, target_mmap_base + FUNCTION_NAME_ADDR_OFFSET,function_name, strlen(function_name) + 1);
7.调用hook函数
写入函数需要的参数
ptrace_writedata(target_pid, target_mmap_base + FUNCTION_PARAM_ADDR_OFFSET, param,strlen(param) + 1);
8.调用dlclose卸载注入so
get_remote_func_address(target_pid, linker_path, (void *) dlclose);
9.恢复现场
ptrace_setregs(target_pid, &original_regs);
10.detach
ptrace_detach(target_pid);