Add a custom prompt for the CSR generation.

Add a new percent escape fucntion.

common/percent.c

@@ -0,0 +1,76 @@
+/* percent.c - Percent escaping
+ *	Copyright (C) 2008 Free Software Foundation, Inc.
+ *
+ * This file is part of GnuPG.
+ *
+ * GnuPG is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * GnuPG is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <config.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <ctype.h>
+
+#include "util.h"
+
+
+/* Create a newly alloced string from STRING with all spaces and
+   control characters converted to plus signs or %xx sequences.  The
+   function returns the new string or NULL in case of a malloc
+   failure.
+
+   Note that we also escape the quote character to work around a bug
+   in the mingw32 runtime which does not correcty handle command line
+   quoting.  We correctly double the quote mark when calling a program
+   (i.e. gpg-protect-tool), but the pre-main code does not notice the
+   double quote as an escaped quote.  We do this also on POSIX systems
+   for consistency.  */
+char *
+percent_plus_escape (const char *string)
+{
+  char *buffer, *p;
+  const char *s;
+  size_t length;
+
+  for (length=1, s=string; *s; s++)
+    {
+      if (*s == '+' || *s == '\"' || *s == '%' 
+          || *(const unsigned char *)s < 0x20)
+        length += 3;
+      else
+        length++;
+    }
+  
+  buffer = p = xtrymalloc (length);
+  if (!buffer)
+    return NULL;
+
+  for (s=string; *s; s++)
+    {
+      if (*s == '+' || *s == '\"' || *s == '%'
+          || *(const unsigned char *)s < 0x20)
+        {
+          snprintf (p, 4, "%%%02X", *(unsigned char *)s);
+          p += 3;
+        }
+      else if (*s == ' ')
+        *p++ = '+';
+      else
+        *p++ = *s;
+    }
+  *p = 0;
+
+  return buffer;
+
+}