diff --git a/g10/build-packet.c b/g10/build-packet.c
index 8388ce3e4..623533f7c 100644
--- a/g10/build-packet.c
+++ b/g10/build-packet.c
@@ -1188,8 +1188,83 @@ string_to_notation(const char *string,int is_utf8)
   return NULL;
 }
 
-/* Return all of the notations stored in the signature SIG.  The
-   caller must free them using free_notation().  */
+/* Like string_to_notation, but store opaque data rather than human
+   readable data.  */
+struct notation *
+blob_to_notation(const char *name, const char *data, size_t len)
+{
+  const char *s;
+  int saw_at=0;
+  struct notation *notation;
+
+  notation=xmalloc_clear(sizeof(*notation));
+
+  if(*name=='-')
+    {
+      notation->flags.ignore=1;
+      name++;
+    }
+
+  if(*name=='!')
+    {
+      notation->flags.critical=1;
+      name++;
+    }
+
+  /* If and when the IETF assigns some official name tags, we'll have
+     to add them here. */
+
+  for( s=name ; *s; s++ )
+    {
+      if( *s=='@')
+	saw_at++;
+
+      /* -notationname is legal without an = sign */
+      if(!*s && notation->flags.ignore)
+	break;
+
+      if (*s == '=')
+        {
+          log_error(_("a notation name may not contain an '=' character\n"));
+          goto fail;
+        }
+
+      if (!isascii (*s) || (!isgraph(*s) && !isspace(*s)))
+	{
+	  log_error(_("a notation name must have only printable characters"
+		      " or spaces\n") );
+	  goto fail;
+	}
+    }
+
+  notation->name=xstrdup (name);
+
+  if(!saw_at && !opt.expert)
+    {
+      log_error(_("a user notation name must contain the '@' character\n"));
+      goto fail;
+    }
+
+  if (saw_at > 1)
+    {
+      log_error(_("a notation name must not contain more than"
+		  " one '@' character\n"));
+      goto fail;
+    }
+
+  notation->bdat = xmalloc (len);
+  memcpy (notation->bdat, data, len);
+  notation->blen = len;
+
+  notation->value = notation_value_to_human_readable_string (notation);
+
+  return notation;
+
+ fail:
+  free_notation(notation);
+  return NULL;
+}
+
 struct notation *
 sig_to_notation(PKT_signature *sig)
 {
diff --git a/g10/packet.h b/g10/packet.h
index 1be9ec389..21c06d776 100644
--- a/g10/packet.h
+++ b/g10/packet.h
@@ -762,6 +762,8 @@ void build_attribute_subpkt(PKT_user_id *uid,byte type,
 			    const void *buf,u32 buflen,
 			    const void *header,u32 headerlen);
 struct notation *string_to_notation(const char *string,int is_utf8);
+struct notation *blob_to_notation(const char *name,
+                                  const char *data, size_t len);
 struct notation *sig_to_notation(PKT_signature *sig);
 void free_notation(struct notation *notation);