removePIE.mm

#include <stdint.h>
#include <mach-o/loader.h>

void hexify(unsigned char *data, uint32_t size){
    while(size--)
        printf("%02x", *data++);}

void fcopy(FILE *f1, FILE *f2){
    char            buffer[BUFSIZ];
    size_t          n;

    while ((n = fread(buffer, sizeof(char), sizeof(buffer), f1)) > 0){
        if (fwrite(buffer, sizeof(char), n, f2) != n)
            printf("Error copying backup");}
}

int main(int argc, char **argv, char **envp) {
    struct mach_header currentHeader;
    //int32_t magic = 0;
    FILE *fp; //edited file pointer
    FILE *fw; //backup file pointer
    char fwName[80];
    char fwPrefix[5] = ".bak"; //app.bak

    if(argc < 1){
        printf("Please enter the filename binary: in the format removePIE filename");
        return EXIT_FAILURE;}
    if((fp = fopen(argv[1], "r+")) == NULL) {
        printf("Error, unable to open file\n");
        return EXIT_FAILURE; }
    //create app.bak filename
    strlcpy(fwName, argv[1], strlen(argv[1]));
    strlcat(fwName, fwPrefix, 5);
    if((fw = fopen(fwName, "w")) == NULL){
    return EXIT_FAILURE;}

    if((fread(&currentHeader.magic, sizeof(int32_t), 1, fp)) == (int)NULL){
        printf("Error reading magic constant in file magic : %x\n",currentHeader.magic);
        return EXIT_FAILURE;
    }
    printf("magic : %x\n", currentHeader.magic);
    if(currentHeader.magic == MH_MAGIC || currentHeader.magic == 0xbebafeca){ //little endian
        printf("loading header\n");
        fseek(fp, 0, SEEK_SET);
        if((fread(&currentHeader, sizeof(currentHeader), 1, fp)) == (int)NULL)
        {
            printf("Error reading MACH-O header");
            return EXIT_FAILURE;
        }
        fseek(fp, 0, SEEK_SET); //set fp back to 0 to get full copy
        printf("\nbacking up application binary...\n");
        fcopy(fp, fw);
        fclose(fw);
        printf("\nbinary backed up to:\t%s\n", fwName);
        printf("\nmach_header:\t");
        hexify((unsigned char *)&currentHeader,sizeof(currentHeader));
        printf("\noriginal flags:\t");
        hexify((unsigned char *)&currentHeader.flags, sizeof(currentHeader.flags));
        printf("\nDisabling ASLR/PIE ...\n");
        currentHeader.flags &= ~MH_PIE;
        printf("new flags:\t");
        hexify((unsigned char *)&currentHeader.flags, sizeof(currentHeader.flags));

        fseek(fp, 0, SEEK_SET);
        if((fwrite(&currentHeader, sizeof(char), 28, fp)) == (int)NULL)
        {
            printf("Error writing to application file %s\n",fwName);
        }
        printf("\nASLR has been disabled for %s\n", argv[1]);
        //exit and close memory
        //free(mach_header);
        fclose(fp);
        return EXIT_SUCCESS;
    }
    else if(currentHeader.magic == MH_CIGAM) // big endian
    {
        printf("file is big-endian, not an iOS binary");
        return EXIT_FAILURE;
    }
    else
    {
        printf("File is not a MACH_O binary");
        return EXIT_FAILURE;
    }
    //exit
    return EXIT_FAILURE;
}
// vim:ft=objc