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-rw-r--r--src/shell-secure-text-buffer.c191
1 files changed, 191 insertions, 0 deletions
diff --git a/src/shell-secure-text-buffer.c b/src/shell-secure-text-buffer.c
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+/* -*- Mode: C; indent-tabs-mode: t; c-basic-offset: 8; tab-width: 8 -*- */
+/* shell-secure-text-buffer.c - secure memory clutter text buffer
+
+ Copyright (C) 2009 Stefan Walter
+ Copyright (C) 2012 Red Hat Inc.
+
+ This program is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Library General Public License as
+ published by the Free Software Foundation; either version 2 of the
+ License, or (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Library General Public License for more details.
+
+ You should have received a copy of the GNU Library General Public
+ License along with the Gnome Library; see the file COPYING.LIB. If not,
+ see <http://www.gnu.org/licenses/>.
+
+ Author: Stef Walter <stefw@gnome.org>
+*/
+
+#include "config.h"
+
+#include "shell-secure-text-buffer.h"
+
+#define GCR_API_SUBJECT_TO_CHANGE
+#include <gcr/gcr-base.h>
+
+#include <string.h>
+
+struct _ShellSecureTextBuffer {
+ ClutterTextBuffer parent;
+ gchar *text;
+ gsize text_size;
+ gsize text_bytes;
+ guint text_chars;
+};
+
+/* Initial size of buffer, in bytes */
+#define MIN_SIZE 16
+
+G_DEFINE_TYPE (ShellSecureTextBuffer, shell_secure_text_buffer, CLUTTER_TYPE_TEXT_BUFFER);
+
+static const gchar *
+shell_secure_text_buffer_real_get_text (ClutterTextBuffer *buffer,
+ gsize *n_bytes)
+{
+ ShellSecureTextBuffer *self = SHELL_SECURE_TEXT_BUFFER (buffer);
+ if (n_bytes)
+ *n_bytes = self->text_bytes;
+ if (!self->text)
+ return "";
+ return self->text;
+}
+
+static guint
+shell_secure_text_buffer_real_get_length (ClutterTextBuffer *buffer)
+{
+ ShellSecureTextBuffer *self = SHELL_SECURE_TEXT_BUFFER (buffer);
+ return self->text_chars;
+}
+
+static guint
+shell_secure_text_buffer_real_insert_text (ClutterTextBuffer *buffer,
+ guint position,
+ const gchar *chars,
+ guint n_chars)
+{
+ ShellSecureTextBuffer *self = SHELL_SECURE_TEXT_BUFFER (buffer);
+ gsize n_bytes;
+ gsize at;
+
+ n_bytes = g_utf8_offset_to_pointer (chars, n_chars) - chars;
+
+ /* Need more memory */
+ if (n_bytes + self->text_bytes + 1 > self->text_size)
+ {
+ /* Calculate our new buffer size */
+ while (n_bytes + self->text_bytes + 1 > self->text_size)
+ {
+ if (self->text_size == 0)
+ {
+ self->text_size = MIN_SIZE;
+ }
+ else
+ {
+ if (2 * self->text_size < CLUTTER_TEXT_BUFFER_MAX_SIZE)
+ {
+ self->text_size *= 2;
+ }
+ else
+ {
+ self->text_size = CLUTTER_TEXT_BUFFER_MAX_SIZE;
+ if (n_bytes > self->text_size - self->text_bytes - 1)
+ {
+ n_bytes = self->text_size - self->text_bytes - 1;
+ n_bytes = g_utf8_find_prev_char (chars, chars + n_bytes + 1) - chars;
+ n_chars = g_utf8_strlen (chars, n_bytes);
+ }
+ break;
+ }
+ }
+ }
+ self->text = gcr_secure_memory_realloc (self->text, self->text_size);
+ }
+
+ /* Actual text insertion */
+ at = g_utf8_offset_to_pointer (self->text, position) - self->text;
+ memmove (self->text + at + n_bytes, self->text + at, self->text_bytes - at);
+ memcpy (self->text + at, chars, n_bytes);
+
+ /* Book keeping */
+ self->text_bytes += n_bytes;
+ self->text_chars += n_chars;
+ self->text[self->text_bytes] = '\0';
+
+ clutter_text_buffer_emit_inserted_text (buffer, position, chars, n_chars);
+ return n_chars;
+}
+
+static guint
+shell_secure_text_buffer_real_delete_text (ClutterTextBuffer *buffer,
+ guint position,
+ guint n_chars)
+{
+ ShellSecureTextBuffer *self = SHELL_SECURE_TEXT_BUFFER (buffer);
+ gsize start, end;
+
+ if (position > self->text_chars)
+ position = self->text_chars;
+ if (position + n_chars > self->text_chars)
+ n_chars = self->text_chars - position;
+
+ if (n_chars > 0)
+ {
+ start = g_utf8_offset_to_pointer (self->text, position) - self->text;
+ end = g_utf8_offset_to_pointer (self->text, position + n_chars) - self->text;
+
+ memmove (self->text + start, self->text + end, self->text_bytes + 1 - end);
+ self->text_chars -= n_chars;
+ self->text_bytes -= (end - start);
+
+ clutter_text_buffer_emit_deleted_text (buffer, position, n_chars);
+ }
+
+ return n_chars;
+}
+
+static void
+shell_secure_text_buffer_init (ShellSecureTextBuffer *self)
+{
+
+}
+
+static void
+shell_secure_text_buffer_finalize (GObject *obj)
+{
+ ShellSecureTextBuffer *self = SHELL_SECURE_TEXT_BUFFER (obj);
+
+ if (self->text)
+ {
+ gcr_secure_memory_strfree (self->text);
+ self->text = NULL;
+ self->text_bytes = self->text_size = 0;
+ self->text_chars = 0;
+ }
+
+ G_OBJECT_CLASS (shell_secure_text_buffer_parent_class)->finalize (obj);
+}
+
+static void
+shell_secure_text_buffer_class_init (ShellSecureTextBufferClass *klass)
+{
+ GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
+ ClutterTextBufferClass *buffer_class = CLUTTER_TEXT_BUFFER_CLASS (klass);
+
+ gobject_class->finalize = shell_secure_text_buffer_finalize;
+
+ buffer_class->get_text = shell_secure_text_buffer_real_get_text;
+ buffer_class->get_length = shell_secure_text_buffer_real_get_length;
+ buffer_class->insert_text = shell_secure_text_buffer_real_insert_text;
+ buffer_class->delete_text = shell_secure_text_buffer_real_delete_text;
+}
+
+ClutterTextBuffer *
+shell_secure_text_buffer_new (void)
+{
+ return g_object_new (SHELL_TYPE_SECURE_TEXT_BUFFER, NULL);
+}