50 lines
1.5 KiB
Diff
50 lines
1.5 KiB
Diff
From bf22713507fe1fc3a2c4b525cf0a88c2dc87a3a2 Mon Sep 17 00:00:00 2001
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From: Joel Hockey <joel.hockey@gmail.com>
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Date: Sun, 16 Aug 2020 17:19:35 -0700
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Subject: [PATCH] Validate UTF8 in xmlEncodeEntities
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Code is currently assuming UTF-8 without validating. Truncated UTF-8
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input can cause out-of-bounds array access.
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Adds further checks to partial fix in 50f06b3e.
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Fixes #178
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---
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entities.c | 16 +++++++++++++++-
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1 file changed, 15 insertions(+), 1 deletion(-)
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diff --git a/entities.c b/entities.c
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index 37b99a56..1a8f86f0 100644
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--- a/entities.c
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+++ b/entities.c
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@@ -704,11 +704,25 @@ xmlEncodeEntitiesInternal(xmlDocPtr doc, const xmlChar *input, int attr) {
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} else {
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/*
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* We assume we have UTF-8 input.
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+ * It must match either:
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+ * 110xxxxx 10xxxxxx
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+ * 1110xxxx 10xxxxxx 10xxxxxx
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+ * 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
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+ * That is:
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+ * cur[0] is 11xxxxxx
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+ * cur[1] is 10xxxxxx
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+ * cur[2] is 10xxxxxx if cur[0] is 111xxxxx
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+ * cur[3] is 10xxxxxx if cur[0] is 1111xxxx
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+ * cur[0] is not 11111xxx
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*/
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char buf[11], *ptr;
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int val = 0, l = 1;
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- if (*cur < 0xC0) {
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+ if (((cur[0] & 0xC0) != 0xC0) ||
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+ ((cur[1] & 0xC0) != 0x80) ||
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+ (((cur[0] & 0xE0) == 0xE0) && ((cur[2] & 0xC0) != 0x80)) ||
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+ (((cur[0] & 0xF0) == 0xF0) && ((cur[3] & 0xC0) != 0x80)) ||
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+ (((cur[0] & 0xF8) == 0xF8))) {
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xmlEntitiesErr(XML_CHECK_NOT_UTF8,
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"xmlEncodeEntities: input not UTF-8");
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if (doc != NULL)
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--
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GitLab
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