diff options
| -rw-r--r-- | core/fpdfapi/parser/fpdf_parser_decode.cpp | 20 | ||||
| -rw-r--r-- | core/fpdfapi/parser/fpdf_parser_decode.h | 3 | ||||
| -rw-r--r-- | core/fpdfapi/parser/fpdf_parser_decode_unittest.cpp | 80 |
3 files changed, 103 insertions, 0 deletions
diff --git a/core/fpdfapi/parser/fpdf_parser_decode.cpp b/core/fpdfapi/parser/fpdf_parser_decode.cpp index eafb8ee8a3..2f73b3a4cb 100644 --- a/core/fpdfapi/parser/fpdf_parser_decode.cpp +++ b/core/fpdfapi/parser/fpdf_parser_decode.cpp @@ -24,6 +24,7 @@ #include "core/fxcodec/fx_codec.h" #include "core/fxcrt/fx_extension.h" #include "third_party/base/numerics/safe_math.h" +#include "third_party/base/stl_util.h" namespace { @@ -87,6 +88,22 @@ const uint16_t PDFDocEncoding[256] = { 0x00f3, 0x00f4, 0x00f5, 0x00f6, 0x00f7, 0x00f8, 0x00f9, 0x00fa, 0x00fb, 0x00fc, 0x00fd, 0x00fe, 0x00ff}; +bool ValidateDecoderPipeline(const CPDF_Array* pDecoders) { + size_t count = pDecoders->GetCount(); + if (count <= 1) + return true; + + // TODO(thestig): Consolidate all the places that use these filter names. + static const char kValidDecoders[][16] = { + "FlateDecode", "Fl", "LZWDecode", "LZW", "ASCII85Decode", "A85", + "ASCIIHexDecode", "AHx", "RunLengthDecode", "RL"}; + for (size_t i = 0; i < count - 1; ++i) { + if (!pdfium::ContainsValue(kValidDecoders, pDecoders->GetStringAt(i))) + return false; + } + return true; +} + uint32_t A85Decode(pdfium::span<const uint8_t> src_span, std::unique_ptr<uint8_t, FxFreeDeleter>* dest_buf, uint32_t* dest_size) { @@ -359,6 +376,9 @@ bool PDF_DataDecode(pdfium::span<const uint8_t> src_span, std::vector<std::pair<ByteString, const CPDF_Object*>> DecoderArray; if (const CPDF_Array* pDecoders = pDecoder->AsArray()) { + if (!ValidateDecoderPipeline(pDecoders)) + return false; + const CPDF_Array* pParamsArray = ToArray(pParams); for (size_t i = 0; i < pDecoders->GetCount(); ++i) { DecoderArray.push_back( diff --git a/core/fpdfapi/parser/fpdf_parser_decode.h b/core/fpdfapi/parser/fpdf_parser_decode.h index e4fdce1037..57ee271656 100644 --- a/core/fpdfapi/parser/fpdf_parser_decode.h +++ b/core/fpdfapi/parser/fpdf_parser_decode.h @@ -15,11 +15,14 @@ #include "third_party/base/span.h" class CCodec_ScanlineDecoder; +class CPDF_Array; class CPDF_Dictionary; // Indexed by 8-bit char code, contains unicode code points. extern const uint16_t PDFDocEncoding[256]; +bool ValidateDecoderPipeline(const CPDF_Array* pDecoders); + ByteString PDF_EncodeString(const ByteString& src, bool bHex); WideString PDF_DecodeText(const uint8_t* pData, uint32_t size); WideString PDF_DecodeText(const ByteString& bstr); diff --git a/core/fpdfapi/parser/fpdf_parser_decode_unittest.cpp b/core/fpdfapi/parser/fpdf_parser_decode_unittest.cpp index b6d7679ef5..a4572396e6 100644 --- a/core/fpdfapi/parser/fpdf_parser_decode_unittest.cpp +++ b/core/fpdfapi/parser/fpdf_parser_decode_unittest.cpp @@ -4,9 +4,89 @@ #include "core/fpdfapi/parser/fpdf_parser_decode.h" +#include "core/fpdfapi/parser/cpdf_array.h" +#include "core/fpdfapi/parser/cpdf_name.h" #include "testing/gtest/include/gtest/gtest.h" #include "testing/test_support.h" +TEST(fpdf_parser_decode, ValidateDecoderPipeline) { + { + // Empty decoder list is always valid. + CPDF_Array decoders; + EXPECT_TRUE(ValidateDecoderPipeline(&decoders)); + } + { + // 1 decoder is always valid. + CPDF_Array decoders; + decoders.AddNew<CPDF_Name>("FlateEncode"); + EXPECT_TRUE(ValidateDecoderPipeline(&decoders)); + } + { + // 1 decoder is always valid, even with an unknown decoder. + CPDF_Array decoders; + decoders.AddNew<CPDF_Name>("FooBar"); + EXPECT_TRUE(ValidateDecoderPipeline(&decoders)); + } + { + // Valid 2 decoder pipeline. + CPDF_Array decoders; + decoders.AddNew<CPDF_Name>("AHx"); + decoders.AddNew<CPDF_Name>("LZWDecode"); + EXPECT_TRUE(ValidateDecoderPipeline(&decoders)); + } + { + // Valid 2 decoder pipeline. + CPDF_Array decoders; + decoders.AddNew<CPDF_Name>("ASCII85Decode"); + decoders.AddNew<CPDF_Name>("ASCII85Decode"); + EXPECT_TRUE(ValidateDecoderPipeline(&decoders)); + } + { + // Valid 5 decoder pipeline. + CPDF_Array decoders; + decoders.AddNew<CPDF_Name>("ASCII85Decode"); + decoders.AddNew<CPDF_Name>("A85"); + decoders.AddNew<CPDF_Name>("RunLengthDecode"); + decoders.AddNew<CPDF_Name>("FlateDecode"); + decoders.AddNew<CPDF_Name>("RL"); + EXPECT_TRUE(ValidateDecoderPipeline(&decoders)); + } + { + // Valid 5 decoder pipeline, with an image decoder at the end. + CPDF_Array decoders; + decoders.AddNew<CPDF_Name>("RunLengthDecode"); + decoders.AddNew<CPDF_Name>("ASCII85Decode"); + decoders.AddNew<CPDF_Name>("FlateDecode"); + decoders.AddNew<CPDF_Name>("LZW"); + decoders.AddNew<CPDF_Name>("DCTDecode"); + EXPECT_TRUE(ValidateDecoderPipeline(&decoders)); + } + { + // Invalid 2 decoder pipeline, with 2 image decoders. + CPDF_Array decoders; + decoders.AddNew<CPDF_Name>("DCTDecode"); + decoders.AddNew<CPDF_Name>("CCITTFaxDecode"); + EXPECT_FALSE(ValidateDecoderPipeline(&decoders)); + } + { + // Invalid 2 decoder pipeline, with 1 image decoder at the start. + CPDF_Array decoders; + decoders.AddNew<CPDF_Name>("DCTDecode"); + decoders.AddNew<CPDF_Name>("FlateDecode"); + EXPECT_FALSE(ValidateDecoderPipeline(&decoders)); + } + { + // Invalid 5 decoder pipeline. + CPDF_Array decoders; + decoders.AddNew<CPDF_Name>("FlateDecode"); + decoders.AddNew<CPDF_Name>("FlateDecode"); + decoders.AddNew<CPDF_Name>("DCTDecode"); + decoders.AddNew<CPDF_Name>("FlateDecode"); + decoders.AddNew<CPDF_Name>("FlateDecode"); + EXPECT_FALSE(ValidateDecoderPipeline(&decoders)); + } +} + TEST(fpdf_parser_decode, A85Decode) { const pdfium::DecodeTestData test_data[] = { // Empty src string. |