1 files changed, 35 insertions, 0 deletions
diff --git a/tools/card-tool-misc.c b/tools/card-tool-misc.c
index 0f5fcc0a0..06fcb6705 100644
--- a/tools/card-tool-misc.c
+++ b/tools/card-tool-misc.c
@@ -42,3 +42,38 @@ find_kinfo (card_info_t info, const char *keyref)
       return kinfo;
   return NULL;
 }
+
+
+/* Convert STRING into a newly allocated buffer while translating the
+ * hex numbers.  Blanks and colons are allowed to separate pairs of
+ * hex digits.  Returns NULL on error or a newly malloced buffer and
+ * its length in LENGTH.  */
+void *
+hex_to_buffer (const char *string, size_t *r_length)
+{
+  unsigned char *buffer;
+  const char *s;
+  size_t n;
+
+  buffer = xtrymalloc (strlen (string)+1);
+  if (!buffer)
+    return NULL;
+  for (s=string, n=0; *s; s++)
+    {
+      if (ascii_isspace (*s) || *s == ':')
+        continue;
+      if (hexdigitp (s) && hexdigitp (s+1))
+        {
+          buffer[n++] = xtoi_2 (s);
+          s++;
+        }
+      else
+        {
+          xfree (buffer);
+          gpg_err_set_errno (EINVAL);
+          return NULL;
+        }
+    }
+  *r_length = n;
+  return buffer;
+}