common: Minor rework of tty_get.

* common/ttyio.c (do_get): Re-indent and remove the checking for char
values larger than 0xa0.  Use explicy control character checking.
--

The code is really old (mid 1998) and with the checking for 0xa0 it
has an implicit assumption of utf-8 or latin-1.  Worse, the check was
for c > 0xa0 and not c == 0xa0 so it never worked as intended.

Signed-off-by: Werner Koch <wk@gnupg.org>

1 files changed, 142 insertions, 118 deletions

diff --git a/common/ttyio.c b/common/ttyio.c
index 374b9f38a..4c095bc03 100644
--- a/common/ttyio.c
+++ b/common/ttyio.c
@@ -404,163 +404,187 @@ tty_print_utf8_string( const byte *p, size_t n )
 static char *
 do_get( const char *prompt, int hidden )
 {
-    char *buf;
+  char *buf;
 #ifndef __riscos__
-    byte cbuf[1];
+  byte cbuf[1];
 #endif
-    int c, n, i;
+  int c, n, i;
 
-    if( batchmode ) {
-	log_error("Sorry, we are in batchmode - can't get input\n");
-	exit(2);
+  if (batchmode)
+    {
+      log_error ("Sorry, we are in batchmode - can't get input\n");
+      exit (2);
     }
 
-    if (no_terminal) {
-	log_error("Sorry, no terminal at all requested - can't get input\n");
-	exit(2);
+  if (no_terminal)
+    {
+      log_error ("Sorry, no terminal at all requested - can't get input\n");
+      exit (2);
     }
 
-    if( !initialized )
-	init_ttyfp();
+  if (!initialized)
+    init_ttyfp ();
 
-    last_prompt_len = 0;
-    tty_printf( "%s", prompt );
-    buf = xmalloc((n=50));
-    i = 0;
+  last_prompt_len = 0;
+  tty_printf ("%s", prompt);
+  buf = xmalloc ((n=50));
+  i = 0;
 
 #ifdef USE_W32_CONSOLE
-    if( hidden )
-	SetConsoleMode(con.in, HID_INPMODE );
-
-    for(;;) {
-	DWORD nread;
+  if (hidden)
+    SetConsoleMode(con.in, HID_INPMODE );
 
-	if( !ReadConsoleA( con.in, cbuf, 1, &nread, NULL ) )
-	    log_fatal("ReadConsole failed: rc=%d", (int)GetLastError() );
-	if( !nread )
-	    continue;
-	if( *cbuf == '\n' )
-	    break;
-
-	if( !hidden )
-	    last_prompt_len++;
-	c = *cbuf;
-	if( c == '\t' )
-	    c = ' ';
-	else if( c > 0xa0 )
-	    ; /* we don't allow 0xa0, as this is a protected blank which may
-	       * confuse the user */
-	else if( iscntrl(c) )
-	    continue;
-	if( !(i < n-1) ) {
-	    n += 50;
-	    buf = xrealloc (buf, n);
-	}
-	buf[i++] = c;
+  for (;;)
+    {
+      DWORD nread;
+
+      if (!ReadConsoleA( con.in, cbuf, 1, &nread, NULL))
+        log_fatal ("ReadConsole failed: rc=%d", (int)GetLastError ());
+      if (!nread)
+        continue;
+      if (*cbuf == '\n')
+        break;
+
+      if (!hidden)
+        last_prompt_len++;
+      c = *cbuf;
+      if (c == '\t')
+        c = ' ';
+      else if ( (c >= 0 && c <= 0x1f) || c == 0x7f)
+        continue;
+      if (!(i < n-1))
+        {
+          n += 50;
+          buf = xrealloc (buf, n);
+        }
+      buf[i++] = c;
     }
 
-    if( hidden )
-	SetConsoleMode(con.in, DEF_INPMODE );
+  if (hidden)
+    SetConsoleMode(con.in, DEF_INPMODE );
 
 #elif defined(__riscos__) || defined(HAVE_W32CE_SYSTEM)
-    do {
+  do
+    {
 #ifdef HAVE_W32CE_SYSTEM
       /* Using getchar is not a correct solution but for now it
          doesn't matter because we have no real console at all.  We
          should rework this as soon as we have switched this entire
          module to estream.  */
-        c = getchar();
+      c = getchar();
 #else
-        c = riscos_getchar();
+      c = riscos_getchar();
 #endif
-        if (c == 0xa || c == 0xd) { /* Return || Enter */
-            c = (int) '\n';
-        } else if (c == 0x8 || c == 0x7f) { /* Backspace || Delete */
-            if (i>0) {
-                i--;
-                if (!hidden) {
-                    last_prompt_len--;
-                    fputc(8, ttyfp);
-                    fputc(32, ttyfp);
-                    fputc(8, ttyfp);
-                    fflush(ttyfp);
+      if (c == 0xa || c == 0xd)  /* Return || Enter */
+        {
+          c = (int) '\n';
+        }
+      else if (c == 0x8 || c == 0x7f) /* Backspace || Delete */
+        {
+          if (i>0)
+            {
+              i--;
+              if (!hidden)
+                {
+                  last_prompt_len--;
+                  fputc(8, ttyfp);
+                  fputc(32, ttyfp);
+                  fputc(8, ttyfp);
+                  fflush(ttyfp);
                 }
-            } else {
-                fputc(7, ttyfp);
-                fflush(ttyfp);
             }
-            continue;
-        } else if (c == (int) '\t') { /* Tab */
-            c = ' ';
-        } else if (c > 0xa0) {
-            ; /* we don't allow 0xa0, as this is a protected blank which may
-               * confuse the user */
-        } else if (iscntrl(c)) {
-            continue;
+          else
+            {
+              fputc(7, ttyfp);
+              fflush(ttyfp);
+            }
+          continue;
+        }
+      else if (c == (int) '\t')  /* Tab */
+        {
+          c = ' ';
+        }
+      else if (c > 0xa0)
+        {
+          ; /* we don't allow 0xa0, as this is a protected blank which may
+             * confuse the user */
         }
-        if(!(i < n-1)) {
-            n += 50;
-            buf = xrealloc (buf, n);
+      else if (iscntrl(c))
+        {
+          continue;
+        }
+      if (!(i < n-1))
+        {
+          n += 50;
+          buf = xrealloc (buf, n);
         }
-        buf[i++] = c;
-        if (!hidden) {
-	    last_prompt_len++;
-            fputc(c, ttyfp);
-            fflush(ttyfp);
+      buf[i++] = c;
+      if (!hidden)
+        {
+          last_prompt_len++;
+          fputc(c, ttyfp);
+          fflush(ttyfp);
         }
-    } while (c != '\n');
-    i = (i>0) ? i-1 : 0;
+    }
+  while (c != '\n');
+  i = (i>0) ? i-1 : 0;
+
 #else /* Other systems. */
-    if( hidden ) {
+
+  if (hidden)
+    {
 #ifdef HAVE_TCGETATTR
-	struct termios term;
-
-	if( tcgetattr(fileno(ttyfp), &termsave) )
-	    log_fatal("tcgetattr() failed: %s\n", strerror(errno) );
-	restore_termios = 1;
-	term = termsave;
-	term.c_lflag &= ~(ECHO | ECHOE | ECHOK | ECHONL);
-	if( tcsetattr( fileno(ttyfp), TCSAFLUSH, &term ) )
-	    log_fatal("tcsetattr() failed: %s\n", strerror(errno) );
+      struct termios term;
+
+      if (tcgetattr(fileno(ttyfp), &termsave))
+        log_fatal("tcgetattr() failed: %s\n", strerror(errno));
+      restore_termios = 1;
+      term = termsave;
+      term.c_lflag &= ~(ECHO | ECHOE | ECHOK | ECHONL);
+      if (tcsetattr( fileno(ttyfp), TCSAFLUSH, &term ) )
+        log_fatal("tcsetattr() failed: %s\n", strerror(errno));
 #endif
     }
 
-    /* fixme: How can we avoid that the \n is echoed w/o disabling
-     * canonical mode - w/o this kill_prompt can't work */
-    while( read(fileno(ttyfp), cbuf, 1) == 1 && *cbuf != '\n' ) {
-	if( !hidden )
-	    last_prompt_len++;
-	c = *cbuf;
-	if( c == CONTROL_D )
-	    log_info("control d found\n");
-	if( c == '\t' )
-	    c = ' ';
-	else if( c > 0xa0 )
-	    ; /* we don't allow 0xa0, as this is a protected blank which may
-	       * confuse the user */
-	else if( iscntrl(c) )
-	    continue;
-	if( !(i < n-1) ) {
-	    n += 50;
-	    buf = xrealloc (buf, n );
-	}
-	buf[i++] = c;
+  /* fixme: How can we avoid that the \n is echoed w/o disabling
+   * canonical mode - w/o this kill_prompt can't work */
+  while (read(fileno(ttyfp), cbuf, 1) == 1 && *cbuf != '\n')
+    {
+      if (!hidden)
+        last_prompt_len++;
+      c = *cbuf;
+      if (c == CONTROL_D)
+        log_info ("Control-D detected\n");
+
+      if (c == '\t') /* Map tab to a space.  */
+        c = ' ';
+      else if ( (c >= 0 && c <= 0x1f) || c == 0x7f)
+        continue; /* Skip all other ASCII control characters.  */
+      if (!(i < n-1))
+        {
+          n += 50;
+          buf = xrealloc (buf, n);
+        }
+      buf[i++] = c;
     }
-    if( *cbuf != '\n' ) {
-	buf[0] = CONTROL_D;
-	i = 1;
+  if (*cbuf != '\n')
+    {
+      buf[0] = CONTROL_D;
+      i = 1;
     }
 
-    if( hidden ) {
+  if (hidden)
+    {
 #ifdef HAVE_TCGETATTR
-	if( tcsetattr(fileno(ttyfp), TCSAFLUSH, &termsave) )
-	    log_error("tcsetattr() failed: %s\n", strerror(errno) );
-	restore_termios = 0;
+      if (tcsetattr(fileno(ttyfp), TCSAFLUSH, &termsave))
+        log_error ("tcsetattr() failed: %s\n", strerror(errno));
+      restore_termios = 0;
 #endif
     }
 #endif /* end unix version */
-    buf[i] = 0;
-    return buf;
+
+  buf[i] = 0;
+  return buf;
 }