diff options
Diffstat (limited to 'isomd5sum/libimplantisomd5.c')
| -rw-r--r-- | isomd5sum/libimplantisomd5.c | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/isomd5sum/libimplantisomd5.c b/isomd5sum/libimplantisomd5.c new file mode 100644 index 000000000..55bb73f2d --- /dev/null +++ b/isomd5sum/libimplantisomd5.c @@ -0,0 +1,204 @@ +/* Copyright 2001 Red Hat, Inc. */ +/* Michael Fulbright msf@redhat.com */ + +#include <stdio.h> +#include <stdlib.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> + +#include "md5.h" +#include "libimplantisomd5.h" + +#define APPDATA_OFFSET 883 +#define SIZE_OFFSET 84 + +/* number of sectors to ignore at end of iso when computing sum */ +#define SKIPSECTORS 15 + +#define MAX(x, y) ((x > y) ? x : y) +#define MIN(x, y) ((x < y) ? x : y) + +/* finds primary volume descriptor and returns info from it */ +/* mediasum must be a preallocated buffer at least 33 bytes long */ +int parsepvd(int isofd, char *mediasum, long long *isosize) { + unsigned char buf[2048]; + long long offset; + unsigned char *p; + + if (lseek(isofd, (off_t)(16L * 2048L), SEEK_SET) == -1) + return ((long long)-1); + + offset = (16L * 2048L); + for (;1;) { + if (read(isofd, buf, 2048) <= 0) + return ((long long)-1); + + if (buf[0] == 1) + /* found primary volume descriptor */ + break; + else if (buf[0] == 255) + /* hit end and didn't find primary volume descriptor */ + return ((long long)-1); + offset += 2048L; + } + + /* read out md5sum */ +#if 0 + memcpy(mediasum, buf + APPDATA_OFFSET + 13, 32); + mediasum[32] = '\0'; + + for (p=mediasum; *p; p++) + if (*p != ' ') + break; + + /* if the md5sum was all spaces, we didn't find md5sum */ + if (!*p) + return -1; +#endif + + /* get isosize */ + *isosize = (buf[SIZE_OFFSET]*0x1000000+buf[SIZE_OFFSET+1]*0x10000 + + buf[SIZE_OFFSET+2]*0x100 + buf[SIZE_OFFSET+3]) * 2048LL; + + return offset; +} + + +unsigned int writeAppData(unsigned char *appdata, char *valstr, unsigned int loc) { + if (loc + strlen(valstr) > 511) { + printf("Attempted to write too much appdata, exiting...\n"); + exit(-1); + } + + memcpy(appdata + loc, valstr, strlen(valstr)); + + return loc+strlen(valstr); +} + + +static void usage(void) { + fprintf(stderr, "implantisomd5: implantisomd5 [--force] [--supported] <isofilename>\n"); + exit(1); +} + + +int implantISOFile(char *fname, int supported, int forceit, char *errstr) { + int i; + int rc; + int isofd; + int nread; + int dirty; + int pvd_offset; + long long isosize, total; + unsigned char md5sum[16]; + unsigned int loc; + unsigned char buf[2048]; + unsigned char orig_appdata[512]; + unsigned char new_appdata[512]; + unsigned char mediasum[33], computedsum[33]; + char md5str[40]; + MD5_CTX md5ctx; + + isofd = open(fname, O_RDWR); + + if (isofd < 0) { + errstr = "Error - Unable to open file %s\n\n"; + return -1; + } + + pvd_offset = parsepvd(isofd, mediasum, &isosize); + if (pvd_offset < 0) { + errstr = "Could not find primary volumne!\n\n"; + return -1; + } + + lseek(isofd, pvd_offset + APPDATA_OFFSET, SEEK_SET); + nread = read(isofd, orig_appdata, 512); + + if (!forceit) { + dirty = 0; + for (i=0; i < 512; i++) + if (orig_appdata[i] != ' ') + dirty = 1; + + if (dirty) { + errstr = "Application data has been used - not implanting md5sum!\n"; + return -1; + } + } else { + /* write out blanks to erase old app data */ + lseek(isofd, pvd_offset + APPDATA_OFFSET, SEEK_SET); + memset(new_appdata, ' ', 512); + i = write(isofd, new_appdata, 512); + if (i<0) { + printf("write failed %d\n", i); + perror(""); + } + } + + /* now do md5sum */ + lseek(isofd, 0L, SEEK_SET); + + MD5_Init(&md5ctx); + + total = 0; + /* read up to 15 sectors from end, due to problems reading last few */ + /* sectors on burned CDs */ + while (total < isosize - SKIPSECTORS*2048) { + nread = read(isofd, buf, 2048); + if (nread <= 0) + break; + + MD5_Update(&md5ctx, buf, nread); + total = total + nread; + } + + MD5_Final(md5sum, &md5ctx); + + *md5str = '\0'; + for (i=0; i<16; i++) { + char tmpstr[4]; + snprintf (tmpstr, 4, "%02x", md5sum[i]); + strcat(md5str, tmpstr); + } + + printf("Inserting md5sum into iso image...\n"); + printf("md5 = %s\n", md5str); + /* memcpy(new_appdata, orig_appdata, 512); */ + memset(new_appdata, ' ', 512); + + loc = 0; + loc = writeAppData(new_appdata, "ISO MD5SUM = ", loc); + loc = writeAppData(new_appdata, md5str, loc); + loc = writeAppData(new_appdata, ";", loc); + snprintf(buf, sizeof(buf), "SKIPSECTORS = %d", SKIPSECTORS); + loc = writeAppData(new_appdata, buf, loc); + loc = writeAppData(new_appdata, ";", loc); + + if (supported) { + printf("Setting supported flag to 1\n"); + loc = writeAppData(new_appdata, "RHLISOSTATUS=1", loc); + } else { + printf("Setting supported flag to 0\n"); + loc = writeAppData(new_appdata, "RHLISOSTATUS=0", loc); + } + + loc = writeAppData(new_appdata, ";", loc); + + loc = writeAppData(new_appdata, "THIS IS NOT THE SAME AS RUNNING MD5SUM ON THIS ISO!!", loc); + + i = lseek(isofd, pvd_offset + APPDATA_OFFSET, SEEK_SET); + if (i<0) + printf("seek failed\n"); + + i = write(isofd, new_appdata, 512); + if (i<0) { + printf("write failed %d\n", i); + perror(""); + } + + close(isofd); + + return 0; +} |