/* Capstone Disassembler Engine */ /* By David Hogarty, 2014 */ // the following must precede stdio (woo, thanks msft) #if defined(_MSC_VER) && _MSC_VER < 1900 #define _CRT_SECURE_NO_WARNINGS #define snprintf _snprintf #endif #include <stdio.h> #include <stdlib.h> #include <string.h> #include <platform.h> #include <capstone.h> static csh handle; struct platform { cs_arch arch; cs_mode mode; unsigned char *code; size_t size; char *comment; int syntax; }; static char *hex_string(unsigned char *str, size_t len) { // returns a malloced string that has the hex version of the string in it // null if failed to malloc char *hex_out; size_t i; hex_out = (char *) malloc(len*2 + 1); // two ascii characters per input character, plus trailing null if (!hex_out) { goto Exit; } for (i = 0; i < len; ++i) { snprintf(hex_out + (i*2), 2, "%02x", str[i]); } hex_out[len*2] = 0; // trailing null Exit: return hex_out; } static void snprint_insn_detail(char * buf, size_t * cur, size_t * left, cs_insn *ins) { size_t used = 0; #define _this_printf(...) \ { \ size_t used = 0; \ used = snprintf(buf + *cur, *left, __VA_ARGS__); \ *left -= used; \ *cur += used; \ } cs_arm *arm; int i; // detail can be NULL on "data" instruction if SKIPDATA option is turned ON if (ins->detail == NULL) return; arm = &(ins->detail->arm); if (arm->op_count) _this_printf("\top_count: %u\n", arm->op_count); for (i = 0; i < arm->op_count; i++) { cs_arm_op *op = &(arm->operands[i]); switch((int)op->type) { default: break; case ARM_OP_REG: _this_printf("\t\toperands[%u].type: REG = %s\n", i, cs_reg_name(handle, op->reg)); break; case ARM_OP_IMM: _this_printf("\t\toperands[%u].type: IMM = 0x%x\n", i, op->imm); break; case ARM_OP_FP: _this_printf("\t\toperands[%u].type: FP = %f\n", i, op->fp); break; case ARM_OP_MEM: _this_printf("\t\toperands[%u].type: MEM\n", i); if (op->mem.base != X86_REG_INVALID) _this_printf("\t\t\toperands[%u].mem.base: REG = %s\n", i, cs_reg_name(handle, op->mem.base)); if (op->mem.index != X86_REG_INVALID) _this_printf("\t\t\toperands[%u].mem.index: REG = %s\n", i, cs_reg_name(handle, op->mem.index)); if (op->mem.scale != 1) _this_printf("\t\t\toperands[%u].mem.scale: %u\n", i, op->mem.scale); if (op->mem.disp != 0) _this_printf("\t\t\toperands[%u].mem.disp: 0x%x\n", i, op->mem.disp); break; case ARM_OP_PIMM: _this_printf("\t\toperands[%u].type: P-IMM = %u\n", i, op->imm); break; case ARM_OP_CIMM: _this_printf("\t\toperands[%u].type: C-IMM = %u\n", i, op->imm); break; } if (op->shift.type != ARM_SFT_INVALID && op->shift.value) { if (op->shift.type < ARM_SFT_ASR_REG) { // shift with constant value _this_printf("\t\t\tShift: %u = %u\n", op->shift.type, op->shift.value); } else { // shift with register _this_printf("\t\t\tShift: %u = %s\n", op->shift.type, cs_reg_name(handle, op->shift.value)); } } } if (arm->cc != ARM_CC_AL && arm->cc != ARM_CC_INVALID) { _this_printf("\tCode condition: %u\n", arm->cc); } if (arm->update_flags) { _this_printf("\tUpdate-flags: True\n"); } if (arm->writeback) { _this_printf("\tWrite-back: True\n"); } #undef _this_printf } static void print_insn_detail(cs_insn *ins) { char a_buf[2048]; size_t cur=0, left=2048; snprint_insn_detail(a_buf, &cur, &left, ins); printf("%s\n", a_buf); } struct invalid_code { unsigned char *code; size_t size; char *comment; }; #define MAX_INVALID_CODES 16 struct invalid_instructions { cs_arch arch; cs_mode mode; char *platform_comment; int num_invalid_codes; struct invalid_code invalid_codes[MAX_INVALID_CODES]; }; static void test_invalids() { struct invalid_instructions invalids[] = {{ CS_ARCH_ARM, CS_MODE_THUMB, "Thumb", 1, {{ (unsigned char *)"\xbd\xe8\x1e\xff", 4, "invalid thumb2 pop because sp used and because both pc and lr are " "present at the same time" }}, }}; struct invalid_instructions * invalid = NULL; uint64_t address = 0x1000; cs_insn *insn; int i; int j; size_t count; printf("\nShould be invalid\n" "-----------------\n"); for (i = 0; i < sizeof(invalids)/sizeof(invalids[0]); i++) { cs_err err; invalid = invalids + i; err = cs_open(invalid->arch, invalid->mode, &handle); if (err) { printf("Failed on cs_open() with error returned: %u\n", err); continue; } cs_option(handle, CS_OPT_DETAIL, CS_OPT_ON); cs_option(handle, CS_OPT_SYNTAX, CS_OPT_SYNTAX_NOREGNAME); for (j = 0; j < invalid->num_invalid_codes; ++j) { struct invalid_code *invalid_code = NULL; char *hex_str = NULL; invalid_code = invalid->invalid_codes + j; hex_str = hex_string(invalid_code->code, invalid_code->size); printf("%s %s: %s\n", invalid->platform_comment, hex_str, invalid_code->comment); free(hex_str); count = cs_disasm(handle, invalid_code->code, invalid_code->size, address, 0, &insn ); if (count) { size_t k; printf(" ERROR:\n"); for (k = 0; k < count; k++) { printf(" 0x%"PRIx64":\t%s\t%s\n", insn[k].address, insn[k].mnemonic, insn[k].op_str); print_insn_detail(&insn[k]); } cs_free(insn, count); } else { printf(" SUCCESS: invalid\n"); } } cs_close(&handle); } } struct valid_code { unsigned char *code; size_t size; uint32_t start_addr; char *expected_out; char *comment; }; #define MAX_VALID_CODES 16 struct valid_instructions { cs_arch arch; cs_mode mode; char *platform_comment; int num_valid_codes; struct valid_code valid_codes[MAX_VALID_CODES]; }; static void test_valids() { struct valid_instructions valids[] = {{ CS_ARCH_ARM, CS_MODE_THUMB, "Thumb", 3, {{ (unsigned char *)"\x00\xf0\x26\xe8", 4, 0x352, "0x352:\tblx\t#0x3a0\n" "\top_count: 1\n" "\t\toperands[0].type: IMM = 0x3a0\n", "thumb2 blx with misaligned immediate" }, { (unsigned char *)"\x05\xdd", 2, 0x1f0, "0x1f0:\tble\t#0x1fe\n" "\top_count: 1\n" "\t\toperands[0].type: IMM = 0x1fe\n" "\tCode condition: 14\n", "thumb b cc with thumb-aligned target" }, { (unsigned char *)"\xbd\xe8\xf0\x8f", 4, 0, "0x0:\tpop.w\t{r4, r5, r6, r7, r8, r9, r10, r11, pc}\n" "\top_count: 9\n" "\t\toperands[0].type: REG = r4\n" "\t\toperands[1].type: REG = r5\n" "\t\toperands[2].type: REG = r6\n" "\t\toperands[3].type: REG = r7\n" "\t\toperands[4].type: REG = r8\n" "\t\toperands[5].type: REG = r9\n" "\t\toperands[6].type: REG = r10\n" "\t\toperands[7].type: REG = r11\n" "\t\toperands[8].type: REG = pc\n", "thumb2 pop that should be valid" }, } }}; struct valid_instructions * valid = NULL; uint64_t address = 0x1000; cs_insn *insn; int i; int j; size_t count; for (i = 0; i < sizeof(valids)/sizeof(valids[0]); i++) { cs_err err; valid = valids + i; err = cs_open(valid->arch, valid->mode, &handle); if (err) { printf("Failed on cs_open() with error returned: %u\n", err); continue; } cs_option(handle, CS_OPT_DETAIL, CS_OPT_ON); cs_option(handle, CS_OPT_SYNTAX, CS_OPT_SYNTAX_NOREGNAME); #define _this_printf(...) \ { \ size_t used = 0; \ used = snprintf(tmp_buf + cur, left, __VA_ARGS__); \ left -= used; \ cur += used; \ } printf("\nShould be valid\n" "---------------\n"); for (j = 0; j < valid->num_valid_codes; ++j) { char tmp_buf[2048]; size_t left = 2048; size_t cur = 0; size_t used = 0; int success = 0; char * hex_str = NULL; struct valid_code * valid_code = NULL; valid_code = valid->valid_codes + j; hex_str = hex_string(valid_code->code, valid_code->size); printf("%s %s @ 0x%04x: %s\n %s", valid->platform_comment, hex_str, valid_code->start_addr, valid_code->comment, valid_code->expected_out); count = cs_disasm(handle, valid_code->code, valid_code->size, valid_code->start_addr, 0, &insn ); if (count) { size_t k; size_t max_len = 0; size_t tmp_len = 0; for (k = 0; k < count; k++) { _this_printf( "0x%"PRIx64":\t%s\t%s\n", insn[k].address, insn[k].mnemonic, insn[k].op_str ); snprint_insn_detail(tmp_buf, &cur, &left, &insn[k]); } max_len = strlen(tmp_buf); tmp_len = strlen(valid_code->expected_out); if (tmp_len > max_len) { max_len = tmp_len; } if (memcmp(tmp_buf, valid_code->expected_out, max_len)) { printf( " ERROR: '''\n%s''' does not match" " expected '''\n%s'''\n", tmp_buf, valid_code->expected_out ); } else { printf(" SUCCESS: valid\n"); } cs_free(insn, count); } else { printf("ERROR: invalid\n"); } } cs_close(&handle); } #undef _this_prinf } int main() { test_invalids(); test_valids(); return 0; }