Add a null UI method

There are cases when, if you pass a NULL UI_METHOD, the called
function will use an internal default.  This is well and good, but
there may be cases when this is undesirable and one would rather send
in a UI that does absolutely nothing (sort of a /dev/null).  UI_null()
is the UI_METHOD for this purpose.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2744)

diff --git a/crypto/ui/build.info b/crypto/ui/build.info
index fcb45af7eb0b5fa6394a67bb4d072700fb8a3b9b..c5d17fb7448a22b49b5e15e07a2ac65de7df30e5 100644 (file)
--- a/crypto/ui/build.info
+++ b/crypto/ui/build.info
@@ -1,3 +1,3 @@
 LIBS=../../libcrypto
 SOURCE[../../libcrypto]=\
-        ui_err.c ui_lib.c ui_openssl.c ui_util.c
+        ui_err.c ui_lib.c ui_openssl.c ui_null.c ui_util.c

diff --git a/crypto/ui/ui_null.c b/crypto/ui/ui_null.c
new file mode 100644 (file)
index 0000000..9e5f6fc
--- /dev/null
+++ b/crypto/ui/ui_null.c
@@ -0,0 +1,26 @@
+/*
+ * Copyright 2017 The OpenSSL Project Authors. All Rights Reserved.
+ *
+ * Licensed under the OpenSSL license (the "License").  You may not use
+ * this file except in compliance with the License.  You can obtain a copy
+ * in the file LICENSE in the source distribution or at
+ * https://www.openssl.org/source/license.html
+ */
+
+#include "ui_locl.h"
+
+static const UI_METHOD ui_null = {
+    "OpenSSL NULL UI",
+    NULL,                        /* opener */
+    NULL,                        /* writer */
+    NULL,                        /* flusher */
+    NULL,                        /* reader */
+    NULL,                        /* closer */
+    NULL
+};
+
+/* The method with all the built-in thingies */
+const UI_METHOD *UI_null(void)
+{
+    return &ui_null;
+}

diff --git a/doc/man3/UI_new.pod b/doc/man3/UI_new.pod
index dedf4dc94abe2ead59eb7286305253df2e61926b..08400d3492d852799bebf86542016dcac37c2cd1 100644 (file)
--- a/doc/man3/UI_new.pod
+++ b/doc/man3/UI_new.pod
@@ -9,7 +9,7 @@ UI_dup_input_boolean, UI_add_info_string, UI_dup_info_string,
 UI_add_error_string, UI_dup_error_string, UI_construct_prompt,
 UI_add_user_data, UI_get0_user_data, UI_get0_result, UI_process,
 UI_ctrl, UI_set_default_method, UI_get_default_method, UI_get_method,
-UI_set_method, UI_OpenSSL, - user interface
+UI_set_method, UI_OpenSSL, UI_null - user interface
 
 =head1 SYNOPSIS
 
@@ -59,6 +59,7 @@ UI_set_method, UI_OpenSSL, - user interface
  const UI_METHOD *UI_set_method(UI *ui, const UI_METHOD *meth);
 
  UI_METHOD *UI_OpenSSL(void);
+ const UI_METHOD *UI_null(void);
 
 =head1 DESCRIPTION
 
@@ -177,6 +178,9 @@ UI_set_method() changes the UI method associated with a given UI.
 UI_OpenSSL() is the default OpenSSL UI method for prompting
 passphrases on the command line.
 
+UI_null() is a UI method that does nothing.  Its use is to avoid
+getting internal defaults for passed UI_METHOD pointers.
+
 =head1 COPYRIGHT
 
 Copyright 2001-2016 The OpenSSL Project Authors. All Rights Reserved.

diff --git a/include/openssl/ui.h b/include/openssl/ui.h
index c5718d23e237af4fe0c3497231291b2a752e03f4..a5fedb5d76a0b367fe0352a0644de8cdd743f195 100644 (file)
--- a/include/openssl/ui.h
+++ b/include/openssl/ui.h
@@ -206,6 +206,12 @@ const UI_METHOD *UI_set_method(UI *ui, const UI_METHOD *meth);
 /* The method with all the built-in thingies */
 UI_METHOD *UI_OpenSSL(void);
 
+/*
+ * NULL method.  Literarily does nothing, but may serve as a placeholder
+ * to avoid internal default.
+ */
+const UI_METHOD *UI_null(void);
+
 /* ---------- For method writers ---------- */
 /*-
    A method contains a number of functions that implement the low level

diff --git a/util/libcrypto.num b/util/libcrypto.num
index 79dddd1ac0e93d4549b39aa396aef2b0b9f837ab..363ab6610c363e55667d7c629a72ecc8b7cb0ea9 100644 (file)
--- a/util/libcrypto.num
+++ b/util/libcrypto.num
@@ -4252,3 +4252,4 @@ EVP_aria_256_ecb                        4202      1_1_1   EXIST::FUNCTION:ARIA
 EVP_aria_256_ctr                        4203   1_1_1   EXIST::FUNCTION:ARIA
 EVP_aria_128_ctr                        4204   1_1_1   EXIST::FUNCTION:ARIA
 EVP_aria_192_ctr                        4205   1_1_1   EXIST::FUNCTION:ARIA
+UI_null                                 4206   1_1_1   EXIST::FUNCTION:UI