| // Copyright 2014 PDFium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com |
| |
| #include "xfa/fxfa/xfa_checksum.h" |
| |
| #include "core/fdrm/crypto/fx_crypt.h" |
| #include "third_party/base/ptr_util.h" |
| |
| namespace { |
| |
| struct FX_BASE64DATA { |
| uint32_t data1 : 2; |
| uint32_t data2 : 6; |
| uint32_t data3 : 4; |
| uint32_t data4 : 4; |
| uint32_t data5 : 6; |
| uint32_t data6 : 2; |
| uint32_t data7 : 8; |
| }; |
| |
| const char g_FXBase64EncoderMap[64] = { |
| 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', |
| 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', |
| 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', |
| 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', |
| '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/', |
| }; |
| |
| void Base64EncodePiece(const FX_BASE64DATA& src, int32_t iBytes, char dst[4]) { |
| dst[0] = g_FXBase64EncoderMap[src.data2]; |
| uint32_t b = src.data1 << 4; |
| if (iBytes > 1) { |
| b |= src.data4; |
| } |
| dst[1] = g_FXBase64EncoderMap[b]; |
| if (iBytes > 1) { |
| b = src.data3 << 2; |
| if (iBytes > 2) { |
| b |= src.data6; |
| } |
| dst[2] = g_FXBase64EncoderMap[b]; |
| if (iBytes > 2) { |
| dst[3] = g_FXBase64EncoderMap[src.data5]; |
| } else { |
| dst[3] = '='; |
| } |
| } else { |
| dst[2] = dst[3] = '='; |
| } |
| } |
| |
| int32_t Base64EncodeA(const uint8_t* pSrc, int32_t iSrcLen, char* pDst) { |
| ASSERT(pSrc); |
| if (iSrcLen < 1) { |
| return 0; |
| } |
| if (!pDst) { |
| int32_t iDstLen = iSrcLen / 3 * 4; |
| if ((iSrcLen % 3) != 0) { |
| iDstLen += 4; |
| } |
| return iDstLen; |
| } |
| FX_BASE64DATA srcData; |
| int32_t iBytes = 3; |
| char* pDstEnd = pDst; |
| while (iSrcLen > 0) { |
| if (iSrcLen > 2) { |
| ((uint8_t*)&srcData)[0] = *pSrc++; |
| ((uint8_t*)&srcData)[1] = *pSrc++; |
| ((uint8_t*)&srcData)[2] = *pSrc++; |
| iSrcLen -= 3; |
| } else { |
| *((uint32_t*)&srcData) = 0; |
| ((uint8_t*)&srcData)[0] = *pSrc++; |
| if (iSrcLen > 1) { |
| ((uint8_t*)&srcData)[1] = *pSrc++; |
| } |
| iBytes = iSrcLen; |
| iSrcLen = 0; |
| } |
| Base64EncodePiece(srcData, iBytes, pDstEnd); |
| pDstEnd += 4; |
| } |
| return pDstEnd - pDst; |
| } |
| |
| } // namespace |
| |
| CXFA_SAXReaderHandler::CXFA_SAXReaderHandler(CXFA_ChecksumContext* pContext) |
| : m_pContext(pContext) { |
| ASSERT(m_pContext); |
| } |
| CXFA_SAXReaderHandler::~CXFA_SAXReaderHandler() {} |
| CXFA_SAXContext* CXFA_SAXReaderHandler::OnTagEnter( |
| const CFX_ByteStringC& bsTagName, |
| CFX_SAXItem::Type eType, |
| uint32_t dwStartPos) { |
| UpdateChecksum(true); |
| if (eType != CFX_SAXItem::Type::Tag && |
| eType != CFX_SAXItem::Type::Instruction) { |
| return nullptr; |
| } |
| m_SAXContext.m_eNode = eType; |
| CFX_ByteTextBuf& textBuf = m_SAXContext.m_TextBuf; |
| textBuf << "<"; |
| if (eType == CFX_SAXItem::Type::Instruction) { |
| textBuf << "?"; |
| } |
| textBuf << bsTagName; |
| m_SAXContext.m_bsTagName = bsTagName; |
| return &m_SAXContext; |
| } |
| |
| void CXFA_SAXReaderHandler::OnTagAttribute(CXFA_SAXContext* pTag, |
| const CFX_ByteStringC& bsAttri, |
| const CFX_ByteStringC& bsValue) { |
| if (!pTag) |
| return; |
| |
| pTag->m_TextBuf << " " << bsAttri << "=\"" << bsValue << "\""; |
| } |
| |
| void CXFA_SAXReaderHandler::OnTagBreak(CXFA_SAXContext* pTag) { |
| if (!pTag) |
| return; |
| |
| pTag->m_TextBuf << ">"; |
| UpdateChecksum(false); |
| } |
| |
| void CXFA_SAXReaderHandler::OnTagData(CXFA_SAXContext* pTag, |
| CFX_SAXItem::Type eType, |
| const CFX_ByteStringC& bsData, |
| uint32_t dwStartPos) { |
| if (!pTag) |
| return; |
| |
| CFX_ByteTextBuf& textBuf = pTag->m_TextBuf; |
| if (eType == CFX_SAXItem::Type::CharData) |
| textBuf << "<![CDATA["; |
| |
| textBuf << bsData; |
| if (eType == CFX_SAXItem::Type::CharData) |
| textBuf << "]]>"; |
| } |
| |
| void CXFA_SAXReaderHandler::OnTagClose(CXFA_SAXContext* pTag, |
| uint32_t dwEndPos) { |
| if (!pTag) |
| return; |
| |
| CFX_ByteTextBuf& textBuf = pTag->m_TextBuf; |
| if (pTag->m_eNode == CFX_SAXItem::Type::Instruction) |
| textBuf << "?>"; |
| else if (pTag->m_eNode == CFX_SAXItem::Type::Tag) |
| textBuf << "></" << pTag->m_bsTagName.AsStringC() << ">"; |
| |
| UpdateChecksum(false); |
| } |
| |
| void CXFA_SAXReaderHandler::OnTagEnd(CXFA_SAXContext* pTag, |
| const CFX_ByteStringC& bsTagName, |
| uint32_t dwEndPos) { |
| if (!pTag) |
| return; |
| |
| pTag->m_TextBuf << "</" << bsTagName << ">"; |
| UpdateChecksum(false); |
| } |
| |
| void CXFA_SAXReaderHandler::OnTargetData(CXFA_SAXContext* pTag, |
| CFX_SAXItem::Type eType, |
| const CFX_ByteStringC& bsData, |
| uint32_t dwStartPos) { |
| if (!pTag && eType != CFX_SAXItem::Type::Comment) |
| return; |
| |
| if (eType == CFX_SAXItem::Type::Comment) { |
| m_SAXContext.m_TextBuf << "<!--" << bsData << "-->"; |
| UpdateChecksum(false); |
| } else { |
| pTag->m_TextBuf << " " << bsData; |
| } |
| } |
| |
| void CXFA_SAXReaderHandler::UpdateChecksum(bool bCheckSpace) { |
| int32_t iLength = m_SAXContext.m_TextBuf.GetLength(); |
| if (iLength < 1) { |
| return; |
| } |
| uint8_t* pBuffer = m_SAXContext.m_TextBuf.GetBuffer(); |
| bool bUpdata = true; |
| if (bCheckSpace) { |
| bUpdata = false; |
| for (int32_t i = 0; i < iLength; i++) { |
| bUpdata = (pBuffer[i] > 0x20); |
| if (bUpdata) { |
| break; |
| } |
| } |
| } |
| if (bUpdata) { |
| m_pContext->Update(CFX_ByteStringC(pBuffer, iLength)); |
| } |
| m_SAXContext.m_TextBuf.Clear(); |
| } |
| |
| CXFA_ChecksumContext::CXFA_ChecksumContext() {} |
| |
| CXFA_ChecksumContext::~CXFA_ChecksumContext() {} |
| |
| void CXFA_ChecksumContext::StartChecksum() { |
| FinishChecksum(); |
| m_pByteContext = pdfium::MakeUnique<CRYPT_sha1_context>(); |
| CRYPT_SHA1Start(m_pByteContext.get()); |
| m_bsChecksum.clear(); |
| m_pSAXReader = pdfium::MakeUnique<CFX_SAXReader>(); |
| } |
| |
| bool CXFA_ChecksumContext::UpdateChecksum( |
| const CFX_RetainPtr<IFX_SeekableReadStream>& pSrcFile, |
| FX_FILESIZE offset, |
| size_t size) { |
| if (!m_pSAXReader || !pSrcFile) |
| return false; |
| |
| if (size < 1) |
| size = pSrcFile->GetSize(); |
| |
| CXFA_SAXReaderHandler handler(this); |
| m_pSAXReader->SetHandler(&handler); |
| if (m_pSAXReader->StartParse( |
| pSrcFile, (uint32_t)offset, (uint32_t)size, |
| CFX_SaxParseMode_NotSkipSpace | CFX_SaxParseMode_NotConvert_amp | |
| CFX_SaxParseMode_NotConvert_lt | CFX_SaxParseMode_NotConvert_gt | |
| CFX_SaxParseMode_NotConvert_sharp) < 0) { |
| return false; |
| } |
| return m_pSAXReader->ContinueParse(nullptr) > 99; |
| } |
| |
| void CXFA_ChecksumContext::FinishChecksum() { |
| m_pSAXReader.reset(); |
| if (m_pByteContext) { |
| uint8_t digest[20]; |
| FXSYS_memset(digest, 0, 20); |
| CRYPT_SHA1Finish(m_pByteContext.get(), digest); |
| int32_t nLen = Base64EncodeA(digest, 20, nullptr); |
| char* pBuffer = m_bsChecksum.GetBuffer(nLen); |
| Base64EncodeA(digest, 20, pBuffer); |
| m_bsChecksum.ReleaseBuffer(nLen); |
| m_pByteContext.reset(); |
| } |
| } |
| |
| CFX_ByteString CXFA_ChecksumContext::GetChecksum() const { |
| return m_bsChecksum; |
| } |
| |
| void CXFA_ChecksumContext::Update(const CFX_ByteStringC& bsText) { |
| if (!m_pByteContext) |
| return; |
| |
| CRYPT_SHA1Update(m_pByteContext.get(), bsText.raw_str(), bsText.GetLength()); |
| } |