commit e350cdd0f2c1c4cdddc8e0a0fced6f50f77ae4d5
author Lei Zhang <thestig@chromium.org> Tue Mar 05 21:35:06 2019 +0000
committer Chromium commit bot <commit-bot@chromium.org> Tue Mar 05 21:35:06 2019 +0000
tree 8487b1874b1a9ff7e9d5c4209b6d7fd4a9cb29b6
parent a1982d50f04c3e300185f2389624953247208d00

Fail early for data matrix barcode input that is too long.

Do not waste time in fuzzers encoding text, only to fail in later
stages.

BUG=chromium:930394

Change-Id: Id328a0e6a6273ba4f6dddfa20fe95a418fd1bfba
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/51491
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>

fxbarcode/datamatrix/BC_HighLevelEncoder.cpp

diff --git a/fxbarcode/datamatrix/BC_HighLevelEncoder.cpp b/fxbarcode/datamatrix/BC_HighLevelEncoder.cpp
index 2731490..34e1a76 100644
--- a/fxbarcode/datamatrix/BC_HighLevelEncoder.cpp
+++ b/fxbarcode/datamatrix/BC_HighLevelEncoder.cpp
@@ -120,6 +120,13 @@
 
 // static
 WideString CBC_HighLevelEncoder::EncodeHighLevel(const WideString& msg) {
+  // Per spec. Alpha numeric input is even shorter.
+  static constexpr size_t kMaxNumericInputLength = 3116;
+
+  // Exit early if the input is too long. It will fail no matter what.
+  if (msg.GetLength() > kMaxNumericInputLength)
+    return WideString();
+
   CBC_EncoderContext context(msg);
   if (context.HasCharactersOutsideISO88591Encoding())
     return WideString();