diff options
Diffstat (limited to 'src/shell-secure-text-buffer.c')
| -rw-r--r-- | src/shell-secure-text-buffer.c | 191 |
1 files changed, 191 insertions, 0 deletions
diff --git a/src/shell-secure-text-buffer.c b/src/shell-secure-text-buffer.c new file mode 100644 index 0000000..8271410 --- /dev/null +++ b/src/shell-secure-text-buffer.c @@ -0,0 +1,191 @@ +/* -*- 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.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); +} |