--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/telepathygabble/src/base64.c Tue Feb 02 01:10:06 2010 +0200
@@ -0,0 +1,196 @@
+/*
+ * base64.c - Base 64 encoding/decoding implementation
+ * Copyright (C) 2006 Collabora Ltd.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "base64.h"
+
+#define DEBUG_FLAG GABBLE_DEBUG_VCARD
+#include "debug.h"
+
+#include <ctype.h>
+#include <string.h>
+
+#include <glib.h>
+
+/*
+|AAAA AABB|BBBB CCCC|CCDD DDDD|
+
+0xFC = 1111 1100
+0x03 = 0000 0011
+0xF0 = 1111 0000
+0x0F = 0000 1111
+0xC0 = 1100 0000
+0x3F = 0011 1111
+
+3 input bytes = 4 output bytes;
+2 input bytes = 2 output bytes;
+1 input byte = 1 output byte.
+*/
+
+static const gchar *encoding =
+ "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+static const guint decoding[256] =
+{
+ /* ... */
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0,
+ /* + */
+ 62,
+ /* ... */
+ 0, 0, 0,
+ /* / , 0-9 */
+ 63,
+ 52, 53, 54, 55, 56, 57, 58, 59, 60, 61,
+ /* ... */
+ 0, 0, 0, 0, 0, 0, 0,
+ /* A */
+ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,
+ 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,
+ /* ... */
+ 0, 0, 0, 0, 0, 0,
+ /* a */
+ 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38,
+ 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51
+};
+
+#define GET_6_BITS_0(s) (((s)[0] & 0xFC) >> 2)
+#define GET_6_BITS_1(s) (((s)[0] & 0x03) << 4) | \
+ (((s)[1] & 0xF0) >> 4)
+#define GET_6_BITS_2(s) (((s)[1] & 0x0F) << 2) | \
+ (((s)[2] & 0xC0) >> 6)
+#define GET_6_BITS_3(s) (((s)[2] & 0x3F) << 0)
+
+#define GET_BYTE_0(s) (((decoding[(guchar)(s)[0]] & 0x3F) << 2) | \
+ ((decoding[(guchar)(s)[1]] & 0x30) >> 4))
+#define GET_BYTE_1(s) (((decoding[(guchar)(s)[1]] & 0x0F) << 4) | \
+ ((decoding[(guchar)(s)[2]] & 0x3C) >> 2))
+#define GET_BYTE_2(s) (((decoding[(guchar)(s)[2]] & 0x03) << 6) | \
+ ((decoding[(guchar)(s)[3]] & 0xFF) << 0))
+
+gchar *base64_encode (guint len, const gchar *str)
+{
+ guint i;
+ GString *tmp;
+
+ /* TODO: calculate requisite output string length and allocate that big a
+ * GString */
+ tmp = g_string_new ("");
+
+ for (i = 0; i < len; i += 3)
+ {
+ guint c1, c2, c3, c4;
+
+ if (i > 0 && (i * 4) % 76 == 0)
+ g_string_append_c (tmp, '\n');
+
+ switch (i + 3 - len)
+ {
+ case 1:
+ c1 = encoding[GET_6_BITS_0 (str + i)];
+ c2 = encoding[GET_6_BITS_1 (str + i)];
+ /* can't use GET_6_BITS_2 because str[i+2] is out of range */
+ c3 = encoding[(str[i + 1] & 0x0f) << 2];
+ c4 = '=';
+ break;
+ case 2:
+ c1 = encoding[GET_6_BITS_0 (str + i)];
+ /* can't use GET_6_BITS_1 because str[i+1] is out of range */
+ c2 = encoding[(str[i] & 0x03) << 4];
+ c3 = '=';
+ c4 = '=';
+ break;
+ default:
+ c1 = encoding[GET_6_BITS_0 (str + i)];
+ c2 = encoding[GET_6_BITS_1 (str + i)];
+ c3 = encoding[GET_6_BITS_2 (str + i)];
+ c4 = encoding[GET_6_BITS_3 (str + i)];
+ }
+
+ g_string_append_printf (tmp, "%c%c%c%c", c1, c2, c3, c4);
+ }
+
+ return g_string_free (tmp, FALSE);
+}
+
+GString *base64_decode (const gchar *str)
+{
+ guint i;
+ GString *tmp;
+ char group[4];
+ guint filled = 0;
+
+ for (i = 0; str[i]; i++)
+ {
+ if (str[i] != 'A' &&
+ str[i] != '=' &&
+ !isspace (str[i]) &&
+ decoding[(guchar) str[i]] == 0)
+ {
+ gabble_debug (DEBUG_FLAG, "bad character %x at byte %u", (guchar)str[i], i);
+ return NULL;
+ }
+ }
+
+ tmp = g_string_new ("");
+
+ for (i = 0; str[i]; i++)
+ {
+ if (isspace (str[i]))
+ continue;
+
+ group[filled++] = str[i];
+
+ if (filled == 4)
+ {
+ if (group[3] == '=')
+ {
+ if (group[2] == '=')
+ {
+ g_string_append_c (tmp, GET_BYTE_0(group));
+ }
+ else
+ {
+ g_string_append_c (tmp, GET_BYTE_0(group));
+ g_string_append_c (tmp, GET_BYTE_1(group));
+ }
+ }
+ else
+ {
+ g_string_append_c (tmp, GET_BYTE_0(group));
+ g_string_append_c (tmp, GET_BYTE_1(group));
+ g_string_append_c (tmp, GET_BYTE_2(group));
+ }
+ filled = 0;
+ }
+ }
+
+ if (filled)
+ {
+ gabble_debug (DEBUG_FLAG, "insufficient padding at end of base64 string:\n%s", str);
+ g_string_free (tmp, TRUE);
+ return NULL;
+ }
+
+ return tmp;
+}
+
+