ropgadget_patternfinder/ropgadget_patternfinder.c

628 lines
13 KiB
C

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
#include <openssl/sha.h>
//Build with: gcc -o ropgadget_patternfinder ropgadget_patternfinder.c -lcrypto
int patterntype = -1;
unsigned int findtarget=1;
unsigned int stride = 4;
unsigned int baseaddr = 0;
int plainout = 0;
unsigned char *filebuf = NULL, *patterndata = NULL, *patternmask = NULL;
size_t filebufsz=0, hashblocksize=0;
size_t patterndata_size=0, patternmask_size=0;
unsigned int dataload_offset = 0, dataload_enabled = 0;
unsigned int addval=0;
int enable_script = 0;
char line_prefix[256];
char script_path[1024];
void hexdump(void *ptr, int buflen)//From ctrtool.
{
unsigned char *buf = (unsigned char*)ptr;
int i, j;
for (i=0; i<buflen; i+=16)
{
printf("%06x: ", i);
for (j=0; j<16; j++)
{
if (i+j < buflen)
{
printf("%02x ", buf[i+j]);
}
else
{
printf(" ");
}
}
printf(" ");
for (j=0; j<16; j++)
{
if (i+j < buflen)
{
printf("%c", (buf[i+j] >= 0x20 && buf[i+j] <= 0x7e) ? buf[i+j] : '.');
}
}
printf("\n");
}
}
int load_bindata(char *arg, unsigned char **buf, unsigned int *size)
{
int i;
unsigned int tmp=0;
unsigned char *bufptr;
FILE *f;
struct stat filestat;
bufptr = *buf;
if(arg[0]!='@')
{
if(bufptr==NULL)
{
tmp = strlen(arg);
if(tmp<2 || (tmp & 1))
{
printf("The length of the input hex param is invalid.\n");
return 4;
}
*size = strlen(arg) / 2;
*buf = (unsigned char*)malloc(*size);
bufptr = *buf;
if(bufptr==NULL)
{
printf("Failed to allocate memory for input buffer.\n");
return 1;
}
memset(bufptr, 0, *size);
}
for(i=0; i<*size; i++)
{
if(i>=strlen(arg))break;
sscanf(&arg[i*2], "%02x", &tmp);
bufptr[i] = (unsigned char)tmp;
}
}
else
{
if(stat(&arg[1], &filestat)==-1)
{
printf("Failed to stat %s\n", &arg[1]);
return 2;
}
f = fopen(&arg[1], "rb");
if(f==NULL)
{
printf("Failed to open %s\n", &arg[1]);
return 2;
}
if(bufptr)
{
if(*size < filestat.st_size)*size = filestat.st_size;
}
else
{
*size = filestat.st_size;
*buf = (unsigned char*)malloc(*size);
bufptr = *buf;
if(bufptr==NULL)
{
printf("Failed to allocate memory for input buffer.\n");
return 1;
}
memset(bufptr, 0, *size);
}
if(fread(bufptr, 1, *size, f) != *size)
{
printf("Failed to read file %s\n", &arg[1]);
fclose(f);
return 3;
}
fclose(f);
}
return 0;
}
int parse_param(char *param, int type)
{
int ret=0;
unsigned int tmpsize=0;
if(strncmp(param, "--patterntype=", 14)==0)
{
if(strncmp(&param[14], "sha256", 6)==0)
{
patterntype = 0;
}
else if(strncmp(&param[14], "datacmp", 7)==0)
{
patterntype = 1;
}
else
{
printf("Invalid pattern-type.\n");
ret = 5;
}
}
if(strncmp(param, "--patterndata=", 14)==0)
{
if(patterndata)
{
free(patterndata);
patterndata = NULL;
}
tmpsize = 0;
ret = load_bindata(&param[14], &patterndata, &tmpsize);
patterndata_size = tmpsize;
}
if(strncmp(param, "--patterndatamask=", 18)==0)
{
if(patterndata)
{
free(patternmask);
patternmask = NULL;
}
tmpsize = 0;
ret = load_bindata(&param[18], &patternmask, &tmpsize);
patternmask_size = tmpsize;
}
if(strncmp(param, "--patternsha256size=", 20)==0)
{
sscanf(&param[20], "0x%x", &tmpsize);
hashblocksize = tmpsize;
}
if(strncmp(param, "--stride=", 9)==0)
{
sscanf(&param[9], "0x%x", &stride);
}
if(strncmp(param, "--findtarget=", 13)==0)
{
sscanf(&param[13], "0x%x", &findtarget);
}
if(strncmp(param, "--baseaddr=", 11)==0)
{
sscanf(&param[11], "0x%x", &baseaddr);
}
if(strncmp(param, "--dataload=", 11)==0)
{
dataload_enabled = 1;
sscanf(&param[11], "0x%x", &dataload_offset);
}
if(strncmp(param, "--addval=", 9)==0)
{
sscanf(&param[9], "0x%x", &addval);
}
if(strncmp(param, "--plainout", 10)==0)
{
plainout = 1;
if(param[10] == '=')
{
strncpy(line_prefix, &param[11], sizeof(line_prefix)-1);
}
}
if(type==0 && strncmp(param, "--script", 8)==0)
{
enable_script = 1;
if(param[8] == '=')
{
strncpy(script_path, &param[9], sizeof(script_path)-1);
}
}
return ret;
}
int verify_params_state()
{
int ret = 0;
if(patterntype==-1)
{
printf("No pattern-type specified.\n");
ret = 5;
}
if(patterntype==0)
{
if(patterndata_size==0)
{
printf("--patternsha256size must be used when pattern-type is sha256.\n");
ret = 5;
}
if(patterndata_size != 0x20)
{
printf("Input hash size is invalid.\n");
ret = 5;
}
}
return ret;
}
int locate_pattern()
{
int ret=0;
size_t pos, i;
unsigned int found, found2;
unsigned int tmpval, tmpval2;
unsigned char calchash[0x20];
for(pos=0; pos<filebufsz; pos+=stride)
{
tmpval = 0;
if(patterntype==0)
{
if(filebufsz - pos < hashblocksize)break;
SHA256(&filebuf[pos], hashblocksize, calchash);
if(memcmp(patterndata, calchash, 0x20)==0)
{
tmpval = 1;
}
}
else if(patterntype==1)
{
if(filebufsz - pos < patterndata_size)break;
if(patternmask==NULL)
{
if(memcmp(patterndata, &filebuf[pos], patterndata_size)==0)
{
tmpval = 1;
}
}
else
{
found2 = 1;
for(i=0; i<patterndata_size; i++)
{
tmpval2 = filebuf[pos+i];
if(i<patternmask_size)tmpval2 &= patternmask[i];
if(tmpval2 != patterndata[i])
{
found2 = 0;
break;
}
}
if(found2)tmpval = 1;
}
}
if(tmpval)
{
if(!dataload_enabled)
{
tmpval = ((unsigned int)pos) + baseaddr;
tmpval+= addval;
if(!plainout)printf("Found the pattern at(value added with 0x%x) ", addval);
printf("%s0x%x", line_prefix, tmpval);
if(!plainout)printf(".");
}
else
{
tmpval = *((unsigned int*)&filebuf[((unsigned int)pos) + dataload_offset]);
tmpval+= addval;
if(!plainout)
{
printf("Found the pattern at ");
printf("%s0x%x", line_prefix, ((unsigned int)pos) + baseaddr);
printf(", u32 value at +0x%x, value added with 0x%x: 0x%x.", dataload_offset, addval, tmpval);
}
else
{
printf("%s0x%x", line_prefix, tmpval);
}
}
printf("\n");
found++;
if(found==findtarget)break;
}
}
if(!found)
{
printf("Failed to find the pattern.\n");
ret = 7;
}
else
{
if(!plainout)printf("Found 0x%x matches.\n", found);
}
return ret;
}
int parse_script(FILE *fscript)
{
int pos, pos2;
int ret=0;
int linenum = 0;
char *strptr, *strptr2;
char linebuf[1024];
char tmpbuf[1024];
memset(linebuf, 0, sizeof(linebuf));
while(fgets(linebuf, 1023, fscript))
{
linenum++;
strptr = strchr(linebuf, '\n');
if(strptr)*strptr = 0;
if(strlen(linebuf)==0 || linebuf[0]=='#')
{
if(linebuf[0]==0)printf("\n");
continue;
}
strptr = linebuf;
if(patternmask_size)
{
free(patternmask);
patternmask = NULL;
patternmask_size=0;
}
dataload_enabled = 0;
dataload_offset = 0;
plainout = 0;
memset(line_prefix, 0, sizeof(line_prefix));
addval = 0;
while(*strptr)
{
if(strptr[0] == ' ')
{
strptr++;
continue;
}
if(strptr[0] == '"' || strptr[0] == '\'')
{
strptr++;
memset(tmpbuf, 0, sizeof(tmpbuf));
for(pos=0; pos<sizeof(tmpbuf)-1; pos++)
{
if(strptr[pos]==0 || strptr[pos] == '\'' || strptr[pos] == '"')break;
tmpbuf[pos] = strptr[pos];
}
if(strptr[pos] == '\'' || strptr[pos] == '"')strptr++;
strptr+= pos;
}
else
{
memset(tmpbuf, 0, sizeof(tmpbuf));
for(pos=0; pos<sizeof(tmpbuf)-1; pos++)
{
if(strptr[pos]==0 || strptr[pos] == ' ')break;
tmpbuf[pos] = strptr[pos];
}
if(strptr[pos] == ' ')strptr++;
strptr+= pos;
}
ret = parse_param(tmpbuf, 1);
if(ret!=0)
{
printf("Line#: %d\n", linenum);
return ret;
}
}
ret = verify_params_state();
if(ret!=0)
{
printf("Line#: %d\n", linenum);
return ret;
}
ret = locate_pattern();
if(ret!=0)
{
printf("Line#: %d\n", linenum);
return ret;
}
}
return ret;
}
int main(int argc, char **argv)
{
int argi;
int ret;
struct stat filestat;
FILE *fbin, *fscript;
if(argc<3)
{
printf("ropgadget_patternfinder by yellows8.\n");
printf("Locates the offset/address of the specified pattern in the input binary. This tool is mainly intended for locating ROP-gadgets, but it could be used for other purposes as well.\n");
printf("<bindata> below can be either hex with any byte-length(unless specified otherwise), or '@' followed by a file-path to load the data from.\n");
printf("Usage:\n");
printf("ropgadget_patternfinder <binary path> <options>\n");
printf("Options:\n");
printf("--patterntype=<type> Selects the pattern-type, which must be one of the following(this option is required): sha256 or datacmp. sha256: Hash every --patternsha256size bytes in the binary, for locating the target pattern. The input bindata(sha256 hash) size must be 0x20-bytes.\n");
printf("--patterndata=<bindata> Pattern data to use during searching the binary, see --patterntype.\n");
printf("--patterndatamask=<bindata> Mask data to use with pattern-type datacmp. The byte-size can be less than the size of patterndata as well. The data loaded from the filebuf is &= with this mask data.\n");
printf("--patternsha256size=0x<hexval> See --patterntype.\n");
printf("--stride=0x<hexval> In the search loop, this is the value that the pos is increased by at the end of each interation. By default this is 0x4.\n");
printf("--findtarget=0x<hexval> Stop searching once this number of matches were found, by default this is 0x1. When this is 0x0, this will not stop until the end of the binary is reached.\n");
printf("--baseaddr=0x<hexval> This is the value which is added to the located offset when printing it, by default this is 0x0.\n");
printf("--dataload=0x<hexval> When used, the u32 at the specified offset relative to the located pattern location, is returned instead of the pattern offset. --baseaddr does not apply to the loaded value.\n");
printf("--addval=0x<hexval> Add the specified value to the value which gets printed.\n");
printf("--plainout[=<prefix text>] Only print the located offset/address, unless an error occurs. If '=<text>' is specified, print that before printing the located offset/address.\n");
printf("--script=<path> Specifies a script from which to load params from(identical to the cmd-line params), each line is for a different pattern to search for. Each param applies to the current line, and all the lines after that until that param gets specified on another line again. When '=<path>' isn't specified, the script is read from stdin. When this --script option is used, all input-param state is reset to the defaults, except for --patterntype, --baseaddr, and --findtarget. When beginning processing each line, the --patterndatamask, --dataload, --addval, and --plainout state is reset to the default before parsing the params each time. When a line is empty, a newline will be printed then processing will skip to the next line. When the first char of a line is '#'(comment), processing will just skip to the next line.\n");
return 0;
}
ret = 0;
memset(line_prefix, 0, sizeof(line_prefix));
memset(script_path, 0, sizeof(script_path));
for(argi=2; argi<argc; argi++)
{
ret = parse_param(argv[argi], 0);
if(ret!=0)break;
}
if(ret!=0)return ret;
if(!enable_script)
{
ret = verify_params_state();
if(ret!=0)
{
free(patterndata);
free(patternmask);
return ret;
}
}
if(stat(argv[1], &filestat)==-1)
{
printf("Failed to stat the input binary: %s.\n", argv[1]);
free(patterndata);
free(patternmask);
return 1;
}
filebufsz = filestat.st_size;
filebuf = malloc(filebufsz);
if(filebuf==NULL)
{
printf("Failed to alloc filebuf.\n");
free(patterndata);
free(patternmask);
return 2;
}
fbin = fopen(argv[1], "rb");
if(fbin==NULL)
{
printf("Failed to open the input binary.\n");
free(filebuf);
free(patterndata);
free(patternmask);
return 3;
}
if(fread(filebuf, 1, filebufsz, fbin) != filebufsz)
{
printf("Failed to read the input binary.\n");
free(filebuf);
free(patterndata);
free(patternmask);
fclose(fbin);
return 4;
}
fclose(fbin);
if(enable_script)
{
free(patterndata);
free(patternmask);
patterndata = NULL;
patternmask = NULL;
patterndata_size=0;
patternmask_size=0;
hashblocksize = 0;
stride = 4;
plainout = 0;
memset(line_prefix, 0, sizeof(line_prefix));
if(script_path[0])
{
fscript = fopen(script_path, "r");
if(fscript==NULL)
{
printf("Failed to open script.\n");
free(filebuf);
return 1;
}
}
else
{
fscript = stdin;
}
}
if(!enable_script)
{
ret = locate_pattern();
}
else
{
ret = parse_script(fscript);
if(script_path[0])fclose(fscript);
}
free(filebuf);
free(patterndata);
free(patternmask);
return ret;
}