1 files changed, 235 insertions, 0 deletions
diff --git a/libpurple/protocols/oscar/encoding.c b/libpurple/protocols/oscar/encoding.c
new file mode 100644
index 0000000000..985f2cb295
--- /dev/null
+++ b/libpurple/protocols/oscar/encoding.c
@@ -0,0 +1,235 @@
+/*
+ * Purple's oscar protocol plugin
+ * This file is the legal property of its developers.
+ * Please see the AUTHORS file distributed alongside this file.
+ *
+ * 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 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 Street, Fifth Floor, Boston, MA  02111-1301  USA
+*/
+
+#include "encoding.h"
+
+static gchar *
+encoding_extract(const char *encoding)
+{
+	char *begin, *end;
+
+	if (encoding == NULL) {
+		return NULL;
+	}
+
+	if (!g_str_has_prefix(encoding, "text/aolrtf; charset=") &&
+		!g_str_has_prefix(encoding, "text/x-aolrtf; charset=") &&
+		!g_str_has_prefix(encoding, "text/plain; charset=")) {
+		return g_strdup(encoding);
+	}
+
+	begin = strchr(encoding, '"');
+	end = strrchr(encoding, '"');
+
+	if ((begin == NULL) || (end == NULL) || (begin >= end)) {
+		return g_strdup(encoding);
+	}
+
+	return g_strndup(begin+1, (end-1) - begin);
+}
+
+gchar *
+oscar_encoding_to_utf8(const char *encoding, const char *text, int textlen)
+{
+	gchar *utf8 = NULL;
+	const gchar *glib_encoding = NULL;
+	gchar *extracted_encoding = encoding_extract(encoding);
+	
+	if (extracted_encoding == NULL || *extracted_encoding == '\0') {
+		purple_debug_info("oscar", "Empty encoding, assuming UTF-8\n");
+	} else if (!g_ascii_strcasecmp(extracted_encoding, "iso-8859-1")) {
+		glib_encoding = "iso-8859-1";
+	} else if (!g_ascii_strcasecmp(extracted_encoding, "ISO-8859-1-Windows-3.1-Latin-1") || !g_ascii_strcasecmp(extracted_encoding, "us-ascii")) {
+		glib_encoding = "Windows-1252";
+	} else if (!g_ascii_strcasecmp(extracted_encoding, "unicode-2-0")) {
+		glib_encoding = "UTF-16BE";
+	} else if (g_ascii_strcasecmp(extracted_encoding, "utf-8")) {
+		purple_debug_warning("oscar", "Unrecognized character encoding \"%s\", attempting to convert to UTF-8 anyway\n", extracted_encoding);
+		glib_encoding = extracted_encoding;
+	}
+
+	if (glib_encoding != NULL) {
+		utf8 = g_convert(text, textlen, "UTF-8", glib_encoding, NULL, NULL, NULL);
+	}
+
+	/*
+	 * If utf8 is still NULL then either the encoding is utf-8 or
+	 * we have been unable to convert the text to utf-8 from the encoding
+	 * that was specified.  So we check if the text is valid utf-8 then
+	 * just copy it.
+	 */
+	if (utf8 == NULL) {
+		if (textlen != 0 && *text != '\0' && !g_utf8_validate(text, textlen, NULL))
+			utf8 = g_strdup(_("(There was an error receiving this message.  The buddy you are speaking with is probably using a different encoding than expected.  If you know what encoding he is using, you can specify it in the advanced account options for your AIM/ICQ account.)"));
+		else
+			utf8 = g_strndup(text, textlen);
+	}
+
+	g_free(extracted_encoding);
+	return utf8;
+}
+
+gchar *
+oscar_utf8_try_convert(PurpleAccount *account, OscarData *od, const gchar *msg)
+{
+	const char *charset = NULL;
+	char *ret = NULL;
+
+	if (msg == NULL)
+		return NULL;
+
+	if (g_utf8_validate(msg, -1, NULL))
+		return g_strdup(msg);
+
+	if (od->icq)
+		charset = purple_account_get_string(account, "encoding", NULL);
+
+	if(charset && *charset)
+		ret = g_convert(msg, -1, "UTF-8", charset, NULL, NULL, NULL);
+
+	if(!ret)
+		ret = purple_utf8_try_convert(msg);
+
+	return ret;
+}
+
+static gchar *
+oscar_convert_to_utf8(const gchar *data, gsize datalen, const char *charsetstr, gboolean fallback)
+{
+	gchar *ret = NULL;
+	GError *err = NULL;
+
+	if ((charsetstr == NULL) || (*charsetstr == '\0'))
+		return NULL;
+
+	if (g_ascii_strcasecmp("UTF-8", charsetstr)) {
+		if (fallback)
+			ret = g_convert_with_fallback(data, datalen, "UTF-8", charsetstr, "?", NULL, NULL, &err);
+		else
+			ret = g_convert(data, datalen, "UTF-8", charsetstr, NULL, NULL, &err);
+		if (err != NULL) {
+			purple_debug_warning("oscar", "Conversion from %s failed: %s.\n",
+							   charsetstr, err->message);
+			g_error_free(err);
+		}
+	} else {
+		if (g_utf8_validate(data, datalen, NULL))
+			ret = g_strndup(data, datalen);
+		else
+			purple_debug_warning("oscar", "String is not valid UTF-8.\n");
+	}
+
+	return ret;
+}
+
+gchar *
+oscar_decode_im(PurpleAccount *account, const char *sourcebn, guint16 charset, const gchar *data, gsize datalen)
+{
+	gchar *ret = NULL;
+	/* charsetstr1 is always set to what the correct encoding should be. */
+	const gchar *charsetstr1, *charsetstr2, *charsetstr3 = NULL;
+
+	if ((datalen == 0) || (data == NULL))
+		return NULL;
+
+	if (charset == AIM_CHARSET_UNICODE) {
+		charsetstr1 = "UTF-16BE";
+		charsetstr2 = "UTF-8";
+	} else if (charset == AIM_CHARSET_LATIN_1) {
+		if ((sourcebn != NULL) && oscar_util_valid_name_icq(sourcebn))
+			charsetstr1 = purple_account_get_string(account, "encoding", OSCAR_DEFAULT_CUSTOM_ENCODING);
+		else
+			charsetstr1 = "ISO-8859-1";
+		charsetstr2 = "UTF-8";
+	} else if (charset == AIM_CHARSET_ASCII) {
+		/* Should just be "ASCII" */
+		charsetstr1 = "ASCII";
+		charsetstr2 = purple_account_get_string(account, "encoding", OSCAR_DEFAULT_CUSTOM_ENCODING);
+	} else if (charset == 0x000d) {
+		/* iChat sending unicode over a Direct IM connection = UTF-8 */
+		/* Mobile AIM client on multiple devices (including Blackberry Tour, Nokia 3100, and LG VX6000) = ISO-8859-1 */
+		charsetstr1 = "UTF-8";
+		charsetstr2 = "ISO-8859-1";
+		charsetstr3 = purple_account_get_string(account, "encoding", OSCAR_DEFAULT_CUSTOM_ENCODING);
+	} else {
+		/* Unknown, hope for valid UTF-8... */
+		charsetstr1 = "UTF-8";
+		charsetstr2 = purple_account_get_string(account, "encoding", OSCAR_DEFAULT_CUSTOM_ENCODING);
+	}
+
+	purple_debug_info("oscar", "Parsing IM, charset=0x%04hx, datalen=%" G_GSIZE_FORMAT ", choice1=%s, choice2=%s, choice3=%s\n",
+					  charset, datalen, charsetstr1, charsetstr2, (charsetstr3 ? charsetstr3 : ""));
+
+	ret = oscar_convert_to_utf8(data, datalen, charsetstr1, FALSE);
+	if (ret == NULL) {
+		if (charsetstr3 != NULL) {
+			/* Try charsetstr2 without allowing substitutions, then fall through to charsetstr3 if needed */
+			ret = oscar_convert_to_utf8(data, datalen, charsetstr2, FALSE);
+			if (ret == NULL)
+				ret = oscar_convert_to_utf8(data, datalen, charsetstr3, TRUE);
+		} else {
+			/* Try charsetstr2, allowing substitutions */
+			ret = oscar_convert_to_utf8(data, datalen, charsetstr2, TRUE);
+		}
+	}
+	if (ret == NULL) {
+		char *str, *salvage, *tmp;
+
+		str = g_malloc(datalen + 1);
+		strncpy(str, data, datalen);
+		str[datalen] = '\0';
+		salvage = purple_utf8_salvage(str);
+		tmp = g_strdup_printf(_("(There was an error receiving this message.  Either you and %s have different encodings selected, or %s has a buggy client.)"),
+					  sourcebn, sourcebn);
+		ret = g_strdup_printf("%s %s", salvage, tmp);
+		g_free(tmp);
+		g_free(str);
+		g_free(salvage);
+	}
+
+	return ret;
+}
+
+static guint16
+get_simplest_charset(const char *utf8)
+{
+	while (*utf8)
+	{
+		if ((unsigned char)(*utf8) > 0x7f) {
+			/* not ASCII! */
+			return AIM_CHARSET_UNICODE;
+		}
+		utf8++;
+	}
+	return AIM_CHARSET_ASCII;
+}
+
+gchar *
+oscar_encode_im(const gchar *msg, gsize *result_len, guint16 *charset, gchar **charsetstr)
+{
+	guint16 msg_charset = get_simplest_charset(msg);
+	if (charset != NULL) {
+		*charset = msg_charset;
+	}
+	if (charsetstr != NULL) {
+		*charsetstr = msg_charset == AIM_CHARSET_ASCII ? "us-ascii" : "unicode-2-0";
+	}
+	return g_convert(msg, -1, msg_charset == AIM_CHARSET_ASCII ? "ASCII" : "UTF-16BE", "UTF-8", NULL, result_len, NULL);
+}