add isomd5sum stuff to anaconda

1 files changed, 181 insertions, 0 deletions

diff --git a/isomd5sum/checkisomd5.c b/isomd5sum/checkisomd5.c
new file mode 100644
index 000000000..653c1bdfd
--- /dev/null
+++ b/isomd5sum/checkisomd5.c
@@ -0,0 +1,181 @@
+/* simple program to check implanted md5sum in an iso 9660 image   */
+/* 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"
+
+/* number of sectors to ignore at end of iso when computing sum */
+#define SKIPSECTORS 0
+
+#define APPDATA_OFFSET 883
+#define SIZE_OFFSET 84
+
+#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;) {
+	read(isofd, buf, 2048);
+	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 */
+    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;
+
+    /* get isosize */
+    *isosize = (buf[SIZE_OFFSET]*0x1000000+buf[SIZE_OFFSET+1]*0x10000 +
+		buf[SIZE_OFFSET+2]*0x100 + buf[SIZE_OFFSET+3]) * 2048LL;
+
+    return offset;
+}
+
+/* returns -1 if no checksum encoded in media, 0 if no match, 1 if match */
+/* mediasum is the sum encoded in media, computedsum is one we compute   */
+/* both strings must be pre-allocated at least 33 chars in length        */
+int checkmd5sum(int isofd, char *mediasum, char *computedsum) {
+    int nread;
+    int nattempt;
+    int i;
+    int dirty;
+    int sector;
+    int appdata_start_offset, appdata_end_offset;
+    long long isosize;
+    unsigned int bufsize = 32768;
+    unsigned char md5sum[16];
+    unsigned int offset;
+    unsigned int len;
+    unsigned char *buf;
+    unsigned char orig_appdata[512];
+    unsigned char new_appdata[512];
+    char orig_md5str[40], md5str[40];
+    MD5_CTX md5ctx;
+
+
+    pvd_offset = parsepvd(isofd, &orig_md5str, &isosize);
+
+    /* seek to application data, read */
+    lseek(isofd, pvd_offset + APPDATA_OFFSET, SEEK_SET);
+    nread = read(isofd, orig_appdata, 512);
+
+    /* read out md5sum */
+    memcpy(mediasum, orig_appdata+13, 32);
+    mediasum[32] = '\0';
+
+    /* rewind, compute md5sum */
+    lseek(isofd, 0L, SEEK_SET);
+
+    MD5_Init(&md5ctx);
+
+    offset = 0;
+
+    buf = malloc(bufsize * sizeof(unsigned char));
+    while (total < isosize - SKIPSECTORS*2048) {
+	nattempt = MIN( isosize - SKIPSECTORS*2048 - total, bufsize );
+	nread = read(isofd, buf, nattempt);
+	if (nread <= 0)
+	    break;
+
+	/* overwrite md5sum we implanted with original data */
+	if (offset < APPDATA_OFFSET && offset+nread >= APPDATA_OFFSET) {
+	    appdata_start_offset = APPDATA_OFFSET - offset;
+	    appdata_end_offset = MIN(appdata_start_offset+MIN(nread, 512),
+				     offset+nread - APPDATA_OFFSET);
+	    len = appdata_end_offset - appdata_start_offset;
+	    memset(buf+appdata_start_offset, ' ', len);
+	} else if (offset >= APPDATA_OFFSET && offset+nread < APPDATA_OFFSET+512) {
+	    appdata_start_offset = 0;
+	    appdata_end_offset = nread;
+	    len = appdata_end_offset - appdata_start_offset;
+	    memset(buf+appdata_start_offset, ' ', len);
+	} else if (offset < APPDATA_OFFSET + 512 && offset+nread >= APPDATA_OFFSET+512) {
+	    appdata_start_offset = 0;
+	    appdata_end_offset = APPDATA_OFFSET+512 - offset;
+	    len = appdata_end_offset - appdata_start_offset;
+	    memset(buf+appdata_start_offset, ' ', len);
+	}
+
+	MD5_Update(&md5ctx, buf, nread);
+	offset = offset + nread;
+    }
+
+    free(buf);
+
+    MD5_Final(md5sum, &md5ctx);
+
+    *computedsum = '\0';
+    for (i=0; i<16; i++) {
+	char tmpstr[4];
+	snprintf (tmpstr, 4, "%02x", md5sum[i]);
+	strcat(computedsum, tmpstr);
+    }
+
+    if (strcmp(mediasum, computedsum))
+	return 0;
+    else
+	return 1;
+    }
+
+#ifdef TESTING
+int main(int argc, char **argv) {
+    int isofd;
+    int rc;
+    unsigned char mediasum[33], computedsum[33];
+
+    printf ("Do not use\n");
+    exit(1);
+
+    if (argc < 2) {
+	printf("Usage: checkisomd5 <isofilename>\n\n");
+	exit(1);
+    }
+
+    isofd = open(argv[1], O_RDWR);
+
+    if (isofd < 0) {
+	fprintf(stderr, "Error - Unable to open file %s\n\n", argv[1]);
+	exit(1);
+    }
+    
+    rc = checkmd5sum(isofd, mediasum, computedsum);
+    printf("%s\n%s\n", mediasum, computedsum);
+    if ( rc == 0)
+	printf("Md5sums differ.\n");
+    else if (rc > 0)
+	printf("Md5sums match.\n");
+    else
+	printf("None checksum information in iso, check skipped.\n");
+
+    close(isofd);
+}
+#endif