Re: [Libguestfs] [PATCH] hivexml

I changed the name of the function to is_valid_xml_string() to avoid camel-case. I also briefly commented the function itself, since it does expect its input to be valid UTF-8. Also, the patch was missing an end-attribute call, which apparently didn't matter in this case since the element was being ended subsequently anyway -- but it missing was an oversight, not intentional. The updated patch to handle illegal XML characters that appear in registry values is below: [todd@tm-nc hivex]# cat hivexml.patch diff -urNp hivex-1.3.3-orig/xml/hivexml.c hivex-1.3.3-new/xml/hivexml.c --- hivex-1.3.3-orig/xml/hivexml.c 2011-09-22 09:17:09.000000000 -0400 +++ hivex-1.3.3-new/xml/hivexml.c 2012-02-01 15:51:06.481728986 -0500 @@ -33,6 +33,7 @@ #endif #include <libxml/xmlwriter.h> +#include <libxml/chvalid.h> #include "hivex.h" @@ -208,6 +209,26 @@ filetime_to_8601 (int64_t windows_ticks) return ret; } +/* + * Check that a UTF-8 string contains only valid XML characters. + * There is an assumption that the input string is valid UTF-8. + */ +static int +is_valid_xml_string(const char *string) +{ + int c; + int pos = 0; + int len = strlen(string); + int charlen = len; + while ((c = xmlGetUTF8Char(string+pos, &charlen)) >= 0) { + if (xmlIsCharQ(c) == 0) + return 0; + pos += charlen; + charlen = len - pos; + } + return 1; +} + static int node_start (hive_h *h, void *writer_v, hive_node_h node, const char *name) { @@ -265,6 +286,20 @@ end_value (xmlTextWriterPtr writer) XML_CHECK (xmlTextWriterEndElement, (writer)); } +static void +start_string(xmlTextWriterPtr writer, const char *encoding) +{ + XML_CHECK (xmlTextWriterStartElement, (writer, BAD_CAST "string")); + if (encoding) + XML_CHECK (xmlTextWriterWriteAttribute, (writer, BAD_CAST "encoding", BAD_CAST encoding)); +} + +static void +end_string(xmlTextWriterPtr writer) +{ + XML_CHECK (xmlTextWriterEndElement, (writer)); +} + static int value_string (hive_h *h, void *writer_v, hive_node_h node, hive_value_h value, hive_type t, size_t len, const char *key, const char *str) @@ -292,9 +327,14 @@ value_string (hive_h *h, void *writer_v, type = "unknown"; } - start_value (writer, key, type, NULL); + int validXML = is_valid_xml_string(str); + start_value (writer, key, type, validXML ? NULL : "base64"); XML_CHECK (xmlTextWriterStartAttribute, (writer, BAD_CAST "value")); - XML_CHECK (xmlTextWriterWriteString, (writer, BAD_CAST str)); + if (validXML) + XML_CHECK (xmlTextWriterWriteString, (writer, BAD_CAST str)); + else + XML_CHECK (xmlTextWriterWriteBase64, (writer, str, 0, strlen(str))); + XML_CHECK (xmlTextWriterEndAttribute, (writer)); end_value (writer); return 0; @@ -310,9 +350,15 @@ value_multiple_strings (hive_h *h, void size_t i; for (i = 0; argv[i] != NULL; ++i) { - XML_CHECK (xmlTextWriterStartElement, (writer, BAD_CAST "string")); - XML_CHECK (xmlTextWriterWriteString, (writer, BAD_CAST argv[i])); - XML_CHECK (xmlTextWriterEndElement, (writer)); + int validXML = is_valid_xml_string(argv[i]); + start_string(writer, validXML ? NULL : "base64"); + XML_CHECK (xmlTextWriterStartAttribute, (writer, BAD_CAST "value")); + if (validXML) + XML_CHECK (xmlTextWriterWriteString, (writer, BAD_CAST argv[i])); + else + XML_CHECK (xmlTextWriterWriteBase64, (writer, argv[i], 0, strlen(argv[i]))); + XML_CHECK (xmlTextWriterEndAttribute, (writer)); + end_string(writer); } end_value (writer); [todd@tm-nc hivex]# _______________________________________________ Libguestfs mailing list Libguestfs(a)redhat.com https://www.redhat.com/mailman/listinfo/libguestfs