[xfa] Remove form checksum abilities

This CL removes the code for verifying and creating checksums associated
with form elements in XFA documents. This was the only code requiring
the SAXReader which has also been removed.

According to the XFA spec and application can decide which parts of the
signatures are supported. This feature is being removed until we
determine if/when it is needed.

Bug: pdfium:1063
Change-Id: Iec2261282340f8fc72a1225d2e0d3e6ddf05edcb
Reviewed-on: https://pdfium-review.googlesource.com/30150
Reviewed-by: Ryan Harrison <rharrison@chromium.org>
Commit-Queue: dsinclair <dsinclair@chromium.org>

1 files changed, 0 insertions, 152 deletions

diff --git a/core/fxcrt/cfx_checksumcontext.cpp b/core/fxcrt/cfx_checksumcontext.cpp
deleted file mode 100644
index 3d3409dceb..0000000000
--- a/core/fxcrt/cfx_checksumcontext.cpp
+++ /dev/null
@@ -1,152 +0,0 @@
-// 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 "core/fxcrt/cfx_checksumcontext.h"
-
-#include "core/fdrm/crypto/fx_crypt.h"
-#include "core/fxcrt/fx_stream.h"
-#include "core/fxcrt/xml/cfx_saxreaderhandler.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
-
-CFX_ChecksumContext::CFX_ChecksumContext() {}
-
-CFX_ChecksumContext::~CFX_ChecksumContext() {}
-
-void CFX_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 CFX_ChecksumContext::UpdateChecksum(
-    const RetainPtr<IFX_SeekableReadStream>& pSrcFile,
-    FX_FILESIZE offset,
-    size_t size) {
-  if (!m_pSAXReader || !pSrcFile)
-    return false;
-
-  if (size < 1)
-    size = pSrcFile->GetSize();
-
-  CFX_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() > 99;
-}
-
-void CFX_ChecksumContext::FinishChecksum() {
-  m_pSAXReader.reset();
-  if (m_pByteContext) {
-    uint8_t digest[20];
-    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();
-  }
-}
-
-ByteString CFX_ChecksumContext::GetChecksum() const {
-  return m_bsChecksum;
-}
-
-void CFX_ChecksumContext::Update(const ByteStringView& bsText) {
-  if (!m_pByteContext)
-    return;
-
-  CRYPT_SHA1Update(m_pByteContext.get(), bsText.raw_str(), bsText.GetLength());
-}