diff -r 000000000000 -r d0f3a028347a telepathygabble/src/base64.c
--- /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;
+}
+
+