The commit code already contains code for validating UTF-8, but it does not
check for invalid values, such as guaranteed non-characters and surrogates. Fix
this by explicitly checking for and rejecting such characters.
Signed-off-by: brian m. carlson <sand...@crustytoothpaste.net>
---
commit.c | 27 ++++++++++++++++++++++-----
t/t3900-i18n-commit.sh | 12 ++++++++++++
2 files changed, 34 insertions(+), 5 deletions(-)
diff --git a/commit.c b/commit.c
index 888e02a..2264106 100644
--- a/commit.c
+++ b/commit.c
@@ -1244,6 +1244,7 @@ static int find_invalid_utf8(const char *buf, int len)
while (len) {
unsigned char c = *buf++;
int bytes, bad_offset;
+ unsigned int codepoint;
len--;
offset++;
@@ -1264,24 +1265,40 @@ static int find_invalid_utf8(const char *buf, int len)
bytes++;
}
- /* Must be between 1 and 5 more bytes */
- if (bytes < 1 || bytes > 5)
+ /*
+ * Must be between 1 and 3 more bytes. Longer sequences result
in
+ * codepoints beyond U+10FFFF, which are guaranteed never to
exist.
+ */
+ if (bytes < 1 || bytes > 3)
return bad_offset;
/* Do we *have* that many bytes? */
if (len < bytes)
return bad_offset;
+ /* Place the encoded bits at the bottom of the value. */
+ codepoint = (c & 0x7f) >> bytes;
+
offset += bytes;
len -= bytes;
/* And verify that they are good continuation bytes */
do {
+ codepoint <<= 6;
+ codepoint |= *buf & 0x3f;
if ((*buf++ & 0xc0) != 0x80)
return bad_offset;
} while (--bytes);
- /* We could/should check the value and length here too */
+ /* No codepoints can ever be allocated beyond U+10FFFF. */
+ if (codepoint > 0x10ffff)
+ return bad_offset;
+ /* Surrogates are only for UTF-16 and cannot be encoded in
UTF-8. */
+ if ((codepoint & 0x1ff800) == 0xd800)
+ return bad_offset;
+ /* U+FFFE and U+FFFF are guaranteed non-characters. */
+ if ((codepoint & 0x1ffffe) == 0xfffe)
+ return bad_offset;
}
return -1;
}
@@ -1292,8 +1309,8 @@ static int find_invalid_utf8(const char *buf, int len)
* If it isn't, it assumes any non-utf8 characters are Latin1,
* and does the conversion.
*
- * Fixme: we should probably also disallow overlong forms and
- * invalid characters. But we don't do that currently.
+ * Fixme: we should probably also disallow overlong forms.
+ * But we don't do that currently.
*/
static int verify_utf8(struct strbuf *buf)
{
diff --git a/t/t3900-i18n-commit.sh b/t/t3900-i18n-commit.sh
index 37ddabb..ee8ba6c 100755
--- a/t/t3900-i18n-commit.sh
+++ b/t/t3900-i18n-commit.sh
@@ -39,6 +39,18 @@ test_expect_failure 'UTF-16 refused because of NULs' '
git commit -a -F "$TEST_DIRECTORY"/t3900/UTF-16.txt
'
+test_expect_success 'UTF-8 invalid characters refused' '
+ test_when_finished "rm -f $HOME/stderr $HOME/invalid" &&
+ rm -f "$HOME/stderr" &&
+ echo "UTF-8 characters" >F &&
+ printf "Commit message\n\nInvalid surrogate:\355\240\200\n" \
+ >"$HOME/invalid" &&
+ git commit -a -F "$HOME/invalid" \
+ 2>"$HOME"/stderr &&
+ grep "did not conform" "$HOME"/stderr
+'
+
+rm -f "$HOME/stderr"
for H in ISO8859-1 eucJP ISO-2022-JP
do
--
1.8.3.1
--
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