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- Committer: Bazaar Package Importer
- Author(s): Ryan Finnie
- Date: 2006-10-01 13:31:56 UTC
- Revision ID: james.westby@ubuntu.com-20061001133156-r2tx2xkds64y9ryx
Tags: upstream-11.1.0.95
Import upstream version 11.1.0.95
added
removed
libimplantisomd5.c
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/* Copyright 2001 Red Hat, Inc. */
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/* Michael Fulbright msf@redhat.com */
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/* 4/2005 Dustin Kirkland (dustin.kirkland@gmail.com) */
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/* Added support for checkpoint fragment sums; */
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/* Allows for exiting media check when bad fragment md5sum'ed */
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#include <stdio.h>
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#include <stdlib.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <fcntl.h>
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#include <string.h>
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#include <unistd.h>
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#include "md5.h"
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#include "libimplantisomd5.h"
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#define APPDATA_OFFSET 883
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#define SIZE_OFFSET 84
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/* Length in characters of string used for fragment md5sum checking */
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#define FRAGMENT_SUM_LENGTH 60
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/* FRAGMENT_COUNT must be an integral divisor or FRAGMENT_SUM_LENGTH */
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/* 60 => 2, 3, 4, 5, 6, 10, 12, 15, 20, or 30 */
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#define FRAGMENT_COUNT 20
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/* number of sectors to ignore at end of iso when computing sum */
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#define SKIPSECTORS 15
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#define MAX(x, y) ((x > y) ? x : y)
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#define MIN(x, y) ((x < y) ? x : y)
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/* finds primary volume descriptor and returns info from it */
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/* mediasum must be a preallocated buffer at least 33 bytes long */
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static int parsepvd(int isofd, char *mediasum, long long *isosize) {
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unsigned char buf[2048];
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long long offset;
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unsigned char *p __attribute__((unused));
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if (lseek(isofd, 16*2048, SEEK_SET) == -1)
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return ((long long)-1);
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offset = (16 * 2048);
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for (;1;) {
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if (read(isofd, buf, 2048L) == -1)
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return ((long long)-1);
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if (buf[0] == 1)
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/* found primary volume descriptor */
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break;
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else if (buf[0] == 255)
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/* hit end and didn't find primary volume descriptor */
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return ((long long)-1);
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offset += 2048L;
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}
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/* read out md5sum */
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#if 0
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memcpy(mediasum, buf + APPDATA_OFFSET + 13, 32);
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mediasum[32] = '\0';
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for (p=mediasum; *p; p++)
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if (*p != ' ')
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break;
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/* if the md5sum was all spaces, we didn't find md5sum */
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if (!*p)
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return -1;
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#endif
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/* get isosize */
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*isosize = (buf[SIZE_OFFSET]*0x1000000+buf[SIZE_OFFSET+1]*0x10000 +
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buf[SIZE_OFFSET+2]*0x100 + buf[SIZE_OFFSET+3]) * 2048LL;
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return offset;
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}
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static unsigned int writeAppData(unsigned char *appdata, char *valstr, unsigned int loc) {
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if (loc + strlen(valstr) > 511) {
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printf("Attempted to write too much appdata, exiting...\n");
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exit(-1);
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}
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memcpy(appdata + loc, valstr, strlen(valstr));
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return loc+strlen(valstr);
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}
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int implantISOFile(char *fname, int supported, int forceit, int quiet, char **errstr) {
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int i;
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int isofd;
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int nread;
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int dirty;
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int pvd_offset;
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int current_fragment = 0;
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int previous_fragment = 0;
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int nattempt;
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long long isosize, total;
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unsigned char md5sum[16];
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unsigned char fragmd5sum[16];
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unsigned int loc;
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unsigned int bufsize = 32768;
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unsigned char *buf;
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unsigned char orig_appdata[512];
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unsigned char new_appdata[512];
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char mediasum[33];
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char md5str[40];
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char fragstr[FRAGMENT_SUM_LENGTH+1];
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MD5_CTX md5ctx, fragmd5ctx;
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isofd = open(fname, O_RDWR);
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if (isofd < 0) {
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*errstr = "Error - Unable to open file %s\n\n";
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return -1;
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}
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pvd_offset = parsepvd(isofd, mediasum, &isosize);
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if (pvd_offset < 0) {
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*errstr = "Could not find primary volumne!\n\n";
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return -1;
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}
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lseek(isofd, pvd_offset + APPDATA_OFFSET, SEEK_SET);
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nread = read(isofd, orig_appdata, 512);
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if (!forceit) {
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dirty = 0;
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for (i=0; i < 512; i++)
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if (orig_appdata[i] != ' ')
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dirty = 1;
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if (dirty) {
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*errstr = "Application data has been used - not implanting md5sum!\n";
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return -1;
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}
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} else {
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/* write out blanks to erase old app data */
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lseek(isofd, pvd_offset + APPDATA_OFFSET, SEEK_SET);
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memset(new_appdata, ' ', 512);
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i = write(isofd, new_appdata, 512);
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if (i<0) {
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printf("write failed %d\n", i);
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perror("");
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}
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}
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/* now do md5sum */
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lseek(isofd, 0L, SEEK_SET);
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MD5_Init(&md5ctx);
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*fragstr = '\0';
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buf = malloc(bufsize * sizeof(unsigned char));
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total = 0;
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/* read up to 15 sectors from end, due to problems reading last few */
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/* sectors on burned CDs */
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while (total < isosize - SKIPSECTORS*2048) {
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nattempt = MIN(isosize - SKIPSECTORS*2048 - total, bufsize);
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nread = read(isofd, buf, nattempt);
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if (nread <= 0)
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break;
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MD5_Update(&md5ctx, buf, nread);
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/* if we're onto the next fragment, calculate the previous sum and write */
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current_fragment = total * (FRAGMENT_COUNT+1) / (isosize - SKIPSECTORS*2048);
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if ( current_fragment != previous_fragment ) {
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memcpy(&fragmd5ctx, &md5ctx, sizeof(MD5_CTX));
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MD5_Final(fragmd5sum, &fragmd5ctx);
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for (i=0; i<FRAGMENT_SUM_LENGTH/FRAGMENT_COUNT; i++) {
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char tmpstr[2];
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snprintf(tmpstr, 2, "%01x", fragmd5sum[i]);
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strncat(fragstr, tmpstr, 2);
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}
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/* printf("\nFragment [%i]: %s\n", previous_fragment, fragstr); */
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previous_fragment = current_fragment;
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}
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total = total + nread;
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}
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free(buf);
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MD5_Final(md5sum, &md5ctx);
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*md5str = '\0';
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for (i=0; i<16; i++) {
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char tmpstr[4];
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snprintf (tmpstr, 4, "%02x", md5sum[i]);
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strncat(md5str, tmpstr, 2);
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}
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if (!quiet) {
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printf("Inserting md5sum into iso image...\n");
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printf("md5 = %s\n", md5str);
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printf("Inserting fragment md5sums into iso image...\n");
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printf("fragmd5 = %s\n", fragstr);
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printf("frags = %d\n", FRAGMENT_COUNT);
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}
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/* memcpy(new_appdata, orig_appdata, 512); */
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memset(new_appdata, ' ', 512);
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loc = 0;
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loc = writeAppData(new_appdata, "ISO MD5SUM = ", loc);
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loc = writeAppData(new_appdata, md5str, loc);
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loc = writeAppData(new_appdata, ";", loc);
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buf = malloc(512 * sizeof(unsigned char));
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snprintf((char *)buf, 512, "SKIPSECTORS = %d", SKIPSECTORS);
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loc = writeAppData(new_appdata, (char *)buf, loc);
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loc = writeAppData(new_appdata, ";", loc);
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free(buf);
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if (supported) {
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if (!quiet)
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printf("Setting supported flag to 1\n");
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loc = writeAppData(new_appdata, "RHLISOSTATUS=1", loc);
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} else {
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if (!quiet)
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printf("Setting supported flag to 0\n");
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loc = writeAppData(new_appdata, "RHLISOSTATUS=0", loc);
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}
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loc = writeAppData(new_appdata, ";", loc);
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loc = writeAppData(new_appdata, "FRAGMENT SUMS = ", loc);
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loc = writeAppData(new_appdata, fragstr, loc);
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loc = writeAppData(new_appdata, ";", loc);
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buf = malloc(512 * sizeof(unsigned char));
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snprintf((char *)buf, 512, "FRAGMENT COUNT = %d", FRAGMENT_COUNT);
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loc = writeAppData(new_appdata, (char *)buf, loc);
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loc = writeAppData(new_appdata, ";", loc);
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free(buf);
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loc = writeAppData(new_appdata, "THIS IS NOT THE SAME AS RUNNING MD5SUM ON THIS ISO!!", loc);
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i = lseek(isofd, pvd_offset + APPDATA_OFFSET, SEEK_SET);
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if (i<0)
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printf("seek failed\n");
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i = write(isofd, new_appdata, 512);
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if (i<0) {
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printf("write failed %d\n", i);
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perror("");
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}
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close(isofd);
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errstr = NULL;
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return 0;
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}
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