+ uint8_t *op = buf_append(msg,2);
+ if (!op) { ok=False; goto out; }
+ size_t l = strlen(signature);
+ assert(l < 65536);
+ put_uint16(op, l);
+ op = buf_append(msg,l);
+ if (!op) { ok=False; goto out; }
+ memcpy(op, signature, l);
+
+ ok = True;
+
+ out:
+ free(signature);