Remove the possibility to disable the UI module entirely

Instead, make it possible to disable the console reader that's part of
the UI module.  This makes it possible to use the UI API and other UI
methods in environments where the console reader isn't useful.

To disable the console reader, configure with 'no-ui-console' /
'disable-ui-console'.

'no-ui' / 'disable-ui' is now an alias for  'no-ui-console' /
'disable-ui-console'.

Fixes #3806

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/3820)

2 files changed, 218 insertions, 209 deletions

diff --git a/crypto/ui/ui_lib.c b/crypto/ui/ui_lib.c
index f4e01bcf38..4469a436c2 100644
--- a/crypto/ui/ui_lib.c
+++ b/crypto/ui/ui_lib.c
@@ -37,9 +37,10 @@ UI *UI_new_method(const UI_METHOD *method)
     }
 
     if (method == NULL)
-        ret->meth = UI_get_default_method();
-    else
-        ret->meth = method;
+        method = UI_get_default_method();
+    if (method == NULL)
+        method = UI_null();
+    ret->meth = method;
 
     if (!CRYPTO_new_ex_data(CRYPTO_EX_INDEX_UI, ret, &ret->ex_data)) {
         OPENSSL_free(ret);
diff --git a/crypto/ui/ui_openssl.c b/crypto/ui/ui_openssl.c
index 42c932656c..977c7ad2b9 100644
--- a/crypto/ui/ui_openssl.c
+++ b/crypto/ui/ui_openssl.c
@@ -9,64 +9,66 @@
 
 #include <openssl/e_os2.h>
 #include <openssl/err.h>
+#include <openssl/ui.h>
 
+#ifndef OPENSSL_NO_UI_CONSOLE
 /*
  * need for #define _POSIX_C_SOURCE arises whenever you pass -ansi to gcc
  * [maybe others?], because it masks interfaces not discussed in standard,
  * sigaction and fileno included. -pedantic would be more appropriate for the
  * intended purposes, but we can't prevent users from adding -ansi.
  */
-#if defined(OPENSSL_SYS_VXWORKS)
-# include <sys/types.h>
-#endif
-
-#if !defined(_POSIX_C_SOURCE) && defined(OPENSSL_SYS_VMS)
-# ifndef _POSIX_C_SOURCE
-#  define _POSIX_C_SOURCE 2
+# if defined(OPENSSL_SYS_VXWORKS)
+#  include <sys/types.h>
 # endif
-#endif
-#include <signal.h>
-#include <stdio.h>
-#include <string.h>
-#include <errno.h>
-
-#if !defined(OPENSSL_SYS_MSDOS) && !defined(OPENSSL_SYS_VMS)
-# ifdef OPENSSL_UNISTD
-#  include OPENSSL_UNISTD
-# else
-#  include <unistd.h>
+
+# if !defined(_POSIX_C_SOURCE) && defined(OPENSSL_SYS_VMS)
+#  ifndef _POSIX_C_SOURCE
+#   define _POSIX_C_SOURCE 2
+#  endif
 # endif
+# include <signal.h>
+# include <stdio.h>
+# include <string.h>
+# include <errno.h>
+
+# if !defined(OPENSSL_SYS_MSDOS) && !defined(OPENSSL_SYS_VMS)
+#  ifdef OPENSSL_UNISTD
+#   include OPENSSL_UNISTD
+#  else
+#   include <unistd.h>
+#  endif
 /*
  * If unistd.h defines _POSIX_VERSION, we conclude that we are on a POSIX
  * system and have sigaction and termios.
  */
-# if defined(_POSIX_VERSION)
+#  if defined(_POSIX_VERSION)
 
-#  define SIGACTION
-#  if !defined(TERMIOS) && !defined(TERMIO) && !defined(SGTTY)
-#   define TERMIOS
-#  endif
+#   define SIGACTION
+#   if !defined(TERMIOS) && !defined(TERMIO) && !defined(SGTTY)
+#    define TERMIOS
+#   endif
 
+#  endif
 # endif
-#endif
 
 /* 06-Apr-92 Luke Brennan    Support for VMS */
-#include "ui_locl.h"
-#include "internal/cryptlib.h"
+# include "ui_locl.h"
+# include "internal/cryptlib.h"
 
-#ifdef OPENSSL_SYS_VMS          /* prototypes for sys$whatever */
-# include <starlet.h>
-# ifdef __DECC
-#  pragma message disable DOLLARID
+# ifdef OPENSSL_SYS_VMS          /* prototypes for sys$whatever */
+#  include <starlet.h>
+#  ifdef __DECC
+#   pragma message disable DOLLARID
+#  endif
 # endif
-#endif
 
-#ifdef WIN_CONSOLE_BUG
-# include <windows.h>
-# ifndef OPENSSL_SYS_WINCE
-#  include <wincon.h>
+# ifdef WIN_CONSOLE_BUG
+#  include <windows.h>
+#  ifndef OPENSSL_SYS_WINCE
+#   include <wincon.h>
+#  endif
 # endif
-#endif
 
 /*
  * There are 6 types of terminal interface supported, TERMIO, TERMIOS, VMS,
@@ -80,81 +82,81 @@
  * may eventually opt to remove it's use entirely.
  */
 
-#if !defined(TERMIOS) && !defined(TERMIO) && !defined(SGTTY)
+# if !defined(TERMIOS) && !defined(TERMIO) && !defined(SGTTY)
 
-# if defined(_LIBC)
-#  undef  TERMIOS
-#  define TERMIO
-#  undef  SGTTY
+#  if defined(_LIBC)
+#   undef  TERMIOS
+#   define TERMIO
+#   undef  SGTTY
 /*
  * We know that VMS, MSDOS, VXWORKS, use entirely other mechanisms.
  */
-# elif !defined(OPENSSL_SYS_VMS) \
+#  elif !defined(OPENSSL_SYS_VMS) \
 	&& !defined(OPENSSL_SYS_MSDOS) \
 	&& !defined(OPENSSL_SYS_VXWORKS)
-#  define TERMIOS
-#  undef  TERMIO
-#  undef  SGTTY
-# endif
+#   define TERMIOS
+#   undef  TERMIO
+#   undef  SGTTY
+#  endif
 
-#endif
+# endif
 
-#ifdef TERMIOS
-# include <termios.h>
-# define TTY_STRUCT             struct termios
-# define TTY_FLAGS              c_lflag
-# define TTY_get(tty,data)      tcgetattr(tty,data)
-# define TTY_set(tty,data)      tcsetattr(tty,TCSANOW,data)
-#endif
+# ifdef TERMIOS
+#  include <termios.h>
+#  define TTY_STRUCT             struct termios
+#  define TTY_FLAGS              c_lflag
+#  define TTY_get(tty,data)      tcgetattr(tty,data)
+#  define TTY_set(tty,data)      tcsetattr(tty,TCSANOW,data)
+# endif
 
-#ifdef TERMIO
-# include <termio.h>
-# define TTY_STRUCT             struct termio
-# define TTY_FLAGS              c_lflag
-# define TTY_get(tty,data)      ioctl(tty,TCGETA,data)
-# define TTY_set(tty,data)      ioctl(tty,TCSETA,data)
-#endif
+# ifdef TERMIO
+#  include <termio.h>
+#  define TTY_STRUCT             struct termio
+#  define TTY_FLAGS              c_lflag
+#  define TTY_get(tty,data)      ioctl(tty,TCGETA,data)
+#  define TTY_set(tty,data)      ioctl(tty,TCSETA,data)
+# endif
 
-#ifdef SGTTY
-# include <sgtty.h>
-# define TTY_STRUCT             struct sgttyb
-# define TTY_FLAGS              sg_flags
-# define TTY_get(tty,data)      ioctl(tty,TIOCGETP,data)
-# define TTY_set(tty,data)      ioctl(tty,TIOCSETP,data)
-#endif
+# ifdef SGTTY
+#  include <sgtty.h>
+#  define TTY_STRUCT             struct sgttyb
+#  define TTY_FLAGS              sg_flags
+#  define TTY_get(tty,data)      ioctl(tty,TIOCGETP,data)
+#  define TTY_set(tty,data)      ioctl(tty,TIOCSETP,data)
+# endif
 
-#if !defined(_LIBC) && !defined(OPENSSL_SYS_MSDOS) && !defined(OPENSSL_SYS_VMS)
-# include <sys/ioctl.h>
-#endif
+# if !defined(_LIBC) && !defined(OPENSSL_SYS_MSDOS) && !defined(OPENSSL_SYS_VMS)
+#  include <sys/ioctl.h>
+# endif
 
-#ifdef OPENSSL_SYS_MSDOS
-# include <conio.h>
-#endif
+# ifdef OPENSSL_SYS_MSDOS
+#  include <conio.h>
+# endif
 
-#ifdef OPENSSL_SYS_VMS
-# include <ssdef.h>
-# include <iodef.h>
-# include <ttdef.h>
-# include <descrip.h>
+# ifdef OPENSSL_SYS_VMS
+#  include <ssdef.h>
+#  include <iodef.h>
+#  include <ttdef.h>
+#  include <descrip.h>
 struct IOSB {
     short iosb$w_value;
     short iosb$w_count;
     long iosb$l_info;
 };
-#endif
+# endif
 
-#ifndef NX509_SIG
-# define NX509_SIG 32
-#endif
+# ifndef NX509_SIG
+#  define NX509_SIG 32
+# endif
 
 /* Define globals.  They are protected by a lock */
-#ifdef SIGACTION
+# ifdef SIGACTION
 static struct sigaction savsig[NX509_SIG];
-#else
+# else
 static void (*savsig[NX509_SIG]) (int);
-#endif
+# endif
 
-#ifdef OPENSSL_SYS_VMS
+# ifdef OPENSSL_SYS_VMS
 static struct IOSB iosb;
 static $DESCRIPTOR(terminal, "TT");
 static long tty_orig[3], tty_new[3]; /* XXX Is there any guarantee that this
@@ -162,26 +164,26 @@ static long tty_orig[3], tty_new[3]; /* XXX Is there any guarantee that this
                                       * structures? */
 static long status;
 static unsigned short channel = 0;
-#elif defined(_WIN32) && !defined(_WIN32_WCE)
+# elif defined(_WIN32) && !defined(_WIN32_WCE)
 static DWORD tty_orig, tty_new;
-#else
-# if !defined(OPENSSL_SYS_MSDOS) || defined(__DJGPP__)
+# else
+#  if !defined(OPENSSL_SYS_MSDOS) || defined(__DJGPP__)
 static TTY_STRUCT tty_orig, tty_new;
+#  endif
 # endif
-#endif
 static FILE *tty_in, *tty_out;
 static int is_a_tty;
 
 /* Declare static functions */
-#if !defined(OPENSSL_SYS_WINCE)
+# if !defined(OPENSSL_SYS_WINCE)
 static int read_till_nl(FILE *);
 static void recsig(int);
 static void pushsig(void);
 static void popsig(void);
-#endif
-#if defined(OPENSSL_SYS_MSDOS) && !defined(_WIN32)
+# endif
+# if defined(OPENSSL_SYS_MSDOS) && !defined(_WIN32)
 static int noecho_fgets(char *buf, int size, FILE *tty);
-#endif
+# endif
 static int read_string_inner(UI *ui, UI_STRING *uis, int echo, int strip_nl);
 
 static int read_string(UI *ui, UI_STRING *uis);
@@ -192,34 +194,6 @@ static int echo_console(UI *ui);
 static int noecho_console(UI *ui);
 static int close_console(UI *ui);
 
-static UI_METHOD ui_openssl = {
-    "OpenSSL default user interface",
-    open_console,
-    write_string,
-    NULL,                       /* No flusher is needed for command lines */
-    read_string,
-    close_console,
-    NULL
-};
-
-static const UI_METHOD *default_UI_meth = &ui_openssl;
-
-void UI_set_default_method(const UI_METHOD *meth)
-{
-    default_UI_meth = meth;
-}
-
-const UI_METHOD *UI_get_default_method(void)
-{
-    return default_UI_meth;
-}
-
-/* The method with all the built-in thingies */
-UI_METHOD *UI_OpenSSL(void)
-{
-    return &ui_openssl;
-}
-
 /*
  * The following function makes sure that info and error strings are printed
  * before any prompt.
@@ -280,11 +254,11 @@ static int read_string(UI *ui, UI_STRING *uis)
     return 1;
 }
 
-#if !defined(OPENSSL_SYS_WINCE)
+# if !defined(OPENSSL_SYS_WINCE)
 /* Internal functions to read a string without echoing */
 static int read_till_nl(FILE *in)
 {
-# define SIZE 4
+#  define SIZE 4
     char buf[SIZE + 1];
 
     do {
@@ -295,7 +269,7 @@ static int read_till_nl(FILE *in)
 }
 
 static volatile sig_atomic_t intr_signal;
-#endif
+# endif
 
 static int read_string_inner(UI *ui, UI_STRING *uis, int echo, int strip_nl)
 {
@@ -303,7 +277,7 @@ static int read_string_inner(UI *ui, UI_STRING *uis, int echo, int strip_nl)
     int ok;
     char result[BUFSIZ];
     int maxsize = BUFSIZ - 1;
-#if !defined(OPENSSL_SYS_WINCE)
+# if !defined(OPENSSL_SYS_WINCE)
     char *p = NULL;
     int echo_eol = !echo;
 
@@ -319,10 +293,10 @@ static int read_string_inner(UI *ui, UI_STRING *uis, int echo, int strip_nl)
     ps = 2;
 
     result[0] = '\0';
-# if defined(_WIN32)
+#  if defined(_WIN32)
     if (is_a_tty) {
         DWORD numread;
-#  if defined(CP_UTF8)
+#   if defined(CP_UTF8)
         if (GetEnvironmentVariableW(L"OPENSSL_WIN32_UTF8", NULL, 0) != 0) {
             WCHAR wresult[BUFSIZ];
 
@@ -342,7 +316,7 @@ static int read_string_inner(UI *ui, UI_STRING *uis, int echo, int strip_nl)
                 OPENSSL_cleanse(wresult, sizeof(wresult));
             }
         } else
-#  endif
+#   endif
         if (ReadConsoleA(GetStdHandle(STD_INPUT_HANDLE),
                          result, maxsize, &numread, NULL)) {
             if (numread >= 2 &&
@@ -354,12 +328,12 @@ static int read_string_inner(UI *ui, UI_STRING *uis, int echo, int strip_nl)
             p = result;
         }
     } else
-# elif defined(OPENSSL_SYS_MSDOS)
+#  elif defined(OPENSSL_SYS_MSDOS)
     if (!echo) {
         noecho_fgets(result, maxsize, tty_in);
         p = result;             /* FIXME: noecho_fgets doesn't return errors */
     } else
-# endif
+#  endif
     p = fgets(result, maxsize, tty_in);
     if (p == NULL)
         goto error;
@@ -385,9 +359,9 @@ static int read_string_inner(UI *ui, UI_STRING *uis, int echo, int strip_nl)
 
     if (ps >= 1)
         popsig();
-#else
+# else
     ok = 1;
-#endif
+# endif
 
     OPENSSL_cleanse(result, BUFSIZ);
     return ok;
@@ -399,10 +373,10 @@ static int open_console(UI *ui)
     CRYPTO_THREAD_write_lock(ui->lock);
     is_a_tty = 1;
 
-#if defined(OPENSSL_SYS_VXWORKS)
+# if defined(OPENSSL_SYS_VXWORKS)
     tty_in = stdin;
     tty_out = stderr;
-#elif defined(_WIN32) && !defined(_WIN32_WCE)
+# elif defined(_WIN32) && !defined(_WIN32_WCE)
     if ((tty_out = fopen("conout$", "w")) == NULL)
         tty_out = stderr;
 
@@ -413,26 +387,26 @@ static int open_console(UI *ui)
         if ((tty_in = fopen("conin$", "r")) == NULL)
             tty_in = stdin;
     }
-#else
-# ifdef OPENSSL_SYS_MSDOS
-#  define DEV_TTY "con"
 # else
-#  define DEV_TTY "/dev/tty"
-# endif
+#  ifdef OPENSSL_SYS_MSDOS
+#   define DEV_TTY "con"
+#  else
+#   define DEV_TTY "/dev/tty"
+#  endif
     if ((tty_in = fopen(DEV_TTY, "r")) == NULL)
         tty_in = stdin;
     if ((tty_out = fopen(DEV_TTY, "w")) == NULL)
         tty_out = stderr;
-#endif
+# endif
 
-#if defined(TTY_get) && !defined(OPENSSL_SYS_VMS)
+# if defined(TTY_get) && !defined(OPENSSL_SYS_VMS)
     if (TTY_get(fileno(tty_in), &tty_orig) == -1) {
-# ifdef ENOTTY
+#  ifdef ENOTTY
         if (errno == ENOTTY)
             is_a_tty = 0;
         else
-# endif
-# ifdef EINVAL
+#  endif
+#  ifdef EINVAL
             /*
              * Ariel Glenn ariel@columbia.edu reports that solaris can return
              * EINVAL instead.  This should be ok
@@ -440,8 +414,8 @@ static int open_console(UI *ui)
         if (errno == EINVAL)
             is_a_tty = 0;
         else
-# endif
-# ifdef ENODEV
+#  endif
+#  ifdef ENODEV
             /*
              * MacOS X returns ENODEV (Operation not supported by device),
              * which seems appropriate.
@@ -449,7 +423,7 @@ static int open_console(UI *ui)
         if (errno == ENODEV)
             is_a_tty = 0;
         else
-# endif
+#  endif
             {
                 char tmp_num[10];
                 BIO_snprintf(tmp_num, sizeof(tmp_num) - 1, "%d", errno);
@@ -459,8 +433,8 @@ static int open_console(UI *ui)
                 return 0;
             }
     }
-#endif
-#ifdef OPENSSL_SYS_VMS
+# endif
+# ifdef OPENSSL_SYS_VMS
     status = sys$assign(&terminal, &channel, 0, 0);
 
     /* if there isn't a TT device, something is very wrong */
@@ -479,22 +453,22 @@ static int open_console(UI *ui)
     /* If IO$_SENSEMODE doesn't work, this is not a terminal device */
     if ((status != SS$_NORMAL) || (iosb.iosb$w_value != SS$_NORMAL))
         is_a_tty = 0;
-#endif
+# endif
     return 1;
 }
 
 static int noecho_console(UI *ui)
 {
-#ifdef TTY_FLAGS
+# ifdef TTY_FLAGS
     memcpy(&(tty_new), &(tty_orig), sizeof(tty_orig));
     tty_new.TTY_FLAGS &= ~ECHO;
-#endif
+# endif
 
-#if defined(TTY_set) && !defined(OPENSSL_SYS_VMS)
+# if defined(TTY_set) && !defined(OPENSSL_SYS_VMS)
     if (is_a_tty && (TTY_set(fileno(tty_in), &tty_new) == -1))
         return 0;
-#endif
-#ifdef OPENSSL_SYS_VMS
+# endif
+# ifdef OPENSSL_SYS_VMS
     if (is_a_tty) {
         tty_new[0] = tty_orig[0];
         tty_new[1] = tty_orig[1] | TT$M_NOECHO;
@@ -514,29 +488,29 @@ static int noecho_console(UI *ui)
             return 0;
         }
     }
-#endif
-#if defined(_WIN32) && !defined(_WIN32_WCE)
+# endif
+# if defined(_WIN32) && !defined(_WIN32_WCE)
     if (is_a_tty) {
         tty_new = tty_orig;
         tty_new &= ~ENABLE_ECHO_INPUT;
         SetConsoleMode(GetStdHandle(STD_INPUT_HANDLE), tty_new);
     }
-#endif
+# endif
     return 1;
 }
 
 static int echo_console(UI *ui)
 {
-#if defined(TTY_set) && !defined(OPENSSL_SYS_VMS)
+# if defined(TTY_set) && !defined(OPENSSL_SYS_VMS)
     memcpy(&(tty_new), &(tty_orig), sizeof(tty_orig));
     tty_new.TTY_FLAGS |= ECHO;
-#endif
+# endif
 
-#if defined(TTY_set) && !defined(OPENSSL_SYS_VMS)
+# if defined(TTY_set) && !defined(OPENSSL_SYS_VMS)
     if (is_a_tty && (TTY_set(fileno(tty_in), &tty_new) == -1))
         return 0;
-#endif
-#ifdef OPENSSL_SYS_VMS
+# endif
+# ifdef OPENSSL_SYS_VMS
     if (is_a_tty) {
         tty_new[0] = tty_orig[0];
         tty_new[1] = tty_orig[1] & ~TT$M_NOECHO;
@@ -556,14 +530,14 @@ static int echo_console(UI *ui)
             return 0;
         }
     }
-#endif
-#if defined(_WIN32) && !defined(_WIN32_WCE)
+# endif
+# if defined(_WIN32) && !defined(_WIN32_WCE)
     if (is_a_tty) {
         tty_new = tty_orig;
         tty_new |= ENABLE_ECHO_INPUT;
         SetConsoleMode(GetStdHandle(STD_INPUT_HANDLE), tty_new);
     }
-#endif
+# endif
     return 1;
 }
 
@@ -573,7 +547,7 @@ static int close_console(UI *ui)
         fclose(tty_in);
     if (tty_out != stderr)
         fclose(tty_out);
-#ifdef OPENSSL_SYS_VMS
+# ifdef OPENSSL_SYS_VMS
     status = sys$dassgn(channel);
     if (status != SS$_NORMAL) {
         char tmp_num[12];
@@ -583,97 +557,97 @@ static int close_console(UI *ui)
         ERR_add_error_data(2, "status=", tmp_num);
         return 0;
     }
-#endif
+# endif
     CRYPTO_THREAD_unlock(ui->lock);
 
     return 1;
 }
 
-#if !defined(OPENSSL_SYS_WINCE)
+# if !defined(OPENSSL_SYS_WINCE)
 /* Internal functions to handle signals and act on them */
 static void pushsig(void)
 {
-# ifndef OPENSSL_SYS_WIN32
+#  ifndef OPENSSL_SYS_WIN32
     int i;
-# endif
-# ifdef SIGACTION
+#  endif
+#  ifdef SIGACTION
     struct sigaction sa;
 
     memset(&sa, 0, sizeof(sa));
     sa.sa_handler = recsig;
-# endif
+#  endif
 
-# ifdef OPENSSL_SYS_WIN32
+#  ifdef OPENSSL_SYS_WIN32
     savsig[SIGABRT] = signal(SIGABRT, recsig);
     savsig[SIGFPE] = signal(SIGFPE, recsig);
     savsig[SIGILL] = signal(SIGILL, recsig);
     savsig[SIGINT] = signal(SIGINT, recsig);
     savsig[SIGSEGV] = signal(SIGSEGV, recsig);
     savsig[SIGTERM] = signal(SIGTERM, recsig);
-# else
+#  else
     for (i = 1; i < NX509_SIG; i++) {
-#  ifdef SIGUSR1
+#   ifdef SIGUSR1
         if (i == SIGUSR1)
             continue;
-#  endif
-#  ifdef SIGUSR2
+#   endif
+#   ifdef SIGUSR2
         if (i == SIGUSR2)
             continue;
-#  endif
-#  ifdef SIGKILL
+#   endif
+#   ifdef SIGKILL
         if (i == SIGKILL)       /* We can't make any action on that. */
             continue;
-#  endif
-#  ifdef SIGACTION
+#   endif
+#   ifdef SIGACTION
         sigaction(i, &sa, &savsig[i]);
-#  else
+#   else
         savsig[i] = signal(i, recsig);
-#  endif
+#   endif
     }
-# endif
+#  endif
 
-# ifdef SIGWINCH
+#  ifdef SIGWINCH
     signal(SIGWINCH, SIG_DFL);
-# endif
+#  endif
 }
 
 static void popsig(void)
 {
-# ifdef OPENSSL_SYS_WIN32
+#  ifdef OPENSSL_SYS_WIN32
     signal(SIGABRT, savsig[SIGABRT]);
     signal(SIGFPE, savsig[SIGFPE]);
     signal(SIGILL, savsig[SIGILL]);
     signal(SIGINT, savsig[SIGINT]);
     signal(SIGSEGV, savsig[SIGSEGV]);
     signal(SIGTERM, savsig[SIGTERM]);
-# else
+#  else
     int i;
     for (i = 1; i < NX509_SIG; i++) {
-#  ifdef SIGUSR1
+#   ifdef SIGUSR1
         if (i == SIGUSR1)
             continue;
-#  endif
-#  ifdef SIGUSR2
+#   endif
+#   ifdef SIGUSR2
         if (i == SIGUSR2)
             continue;
-#  endif
-#  ifdef SIGACTION
+#   endif
+#   ifdef SIGACTION
         sigaction(i, &savsig[i], NULL);
-#  else
+#   else
         signal(i, savsig[i]);
-#  endif
+#   endif
     }
-# endif
+#  endif
 }
 
 static void recsig(int i)
 {
     intr_signal = i;
 }
-#endif
+# endif
 
 /* Internal functions specific for Windows */
-#if defined(OPENSSL_SYS_MSDOS) && !defined(_WIN32)
+# if defined(OPENSSL_SYS_MSDOS) && !defined(_WIN32)
 static int noecho_fgets(char *buf, int size, FILE *tty)
 {
     int i;
@@ -686,11 +660,11 @@ static int noecho_fgets(char *buf, int size, FILE *tty)
             break;
         }
         size--;
-# if defined(_WIN32)
+#  if defined(_WIN32)
         i = _getch();
-# else
+#  else
         i = getch();
-# endif
+#  endif
         if (i == '\r')
             i = '\n';
         *(p++) = i;
@@ -699,7 +673,7 @@ static int noecho_fgets(char *buf, int size, FILE *tty)
             break;
         }
     }
-# ifdef WIN_CONSOLE_BUG
+#  ifdef WIN_CONSOLE_BUG
     /*
      * Win95 has several evil console bugs: one of these is that the last
      * character read using getch() is passed to the next read: this is
@@ -711,7 +685,41 @@ static int noecho_fgets(char *buf, int size, FILE *tty)
         inh = GetStdHandle(STD_INPUT_HANDLE);
         FlushConsoleInputBuffer(inh);
     }
-# endif
+#  endif
     return (strlen(buf));
 }
+# endif
+
+static UI_METHOD ui_openssl = {
+    "OpenSSL default user interface",
+    open_console,
+    write_string,
+    NULL,                       /* No flusher is needed for command lines */
+    read_string,
+    close_console,
+    NULL
+};
+
+/* The method with all the built-in console thingies */
+UI_METHOD *UI_OpenSSL(void)
+{
+    return &ui_openssl;
+}
+
+static const UI_METHOD *default_UI_meth = &ui_openssl;
+
+#else
+
+static const UI_METHOD *default_UI_meth = NULL;
+
 #endif
+
+void UI_set_default_method(const UI_METHOD *meth)
+{
+    default_UI_meth = meth;
+}
+
+const UI_METHOD *UI_get_default_method(void)
+{
+    return default_UI_meth;
+}