dns cert support

[Peter Palfrader]

On Wed, 05 Apr 2006, Werner Koch wrote:

> On Wed, 5 Apr 2006 10:02:28 +0200, Peter Palfrader said:
> 
> > +      const char *tmp = fpr;
> > +      while (*tmp)
> > +	{
> > +	  if (isxdigit(*tmp))
> 
> Will segv on many non-glibc systems if you pass non-ascii characters
> to it.  Never ever use isfoo functions without additional checks.

ick.

Index: make-dns-cert.c
===================================================================
--- make-dns-cert.c	(revision 4091)
+++ make-dns-cert.c	(working copy)
@@ -97,7 +97,22 @@
 
   if(fpr)
     {
-      fprlen=strlen(fpr);
+      const char *tmp = fpr;
+      while (*tmp)
+	{
+	  if ((*tmp >= 'A' && *tmp <= 'F') ||
+	      (*tmp >= 'a' && *tmp <= 'f') ||
+	      (*tmp >= '0' && *tmp <= '9'))
+	    {
+	      fprlen++;
+	    }
+	  else if (*tmp != ' ' && *tmp != '\t')
+	    {
+	      printf("Fingerprint must consist of only hex digits (and whitespace)\n");
+	      return 1;
+	    }
+	  tmp++;
+	}
       if(fprlen%2)
 	{
 	  printf("Fingerprint must be an even number of characters\n");

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