fgas/ code cleanup.

xfa/fxfa/app/xfa_checksum.cpp

 // 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/include/xfa_checksum.h"
 
 #include "core/fdrm/crypto/include/fx_crypt.h"
-#include "xfa/fgas/crt/fgas_algorithm.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 FX_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,
+                       FX_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, FX_CHAR* pDst) {
+  ASSERT(pSrc != NULL);
+  if (iSrcLen < 1) {
+    return 0;
+  }
+  if (pDst == NULL) {
+    int32_t iDstLen = iSrcLen / 3 * 4;
+    if ((iSrcLen % 3) != 0) {
+      iDstLen += 4;
+    }
+    return iDstLen;
+  }
+  FX_BASE64DATA srcData;
+  int32_t iBytes = 3;
+  FX_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() {}
 void* CXFA_SAXReaderHandler::OnTagEnter(const CFX_ByteStringC& bsTagName,
                                         FX_SAXNODE eType,
                                         uint32_t dwStartPos) {
   UpdateChecksum(TRUE);
@@ skipping 139 matching lines @@
   return m_pSAXReader->ContinueParse(NULL) > 99;
 }
 
 void CXFA_ChecksumContext::FinishChecksum() {
   delete m_pSAXReader;
   m_pSAXReader = nullptr;
   if (m_pByteContext) {
     uint8_t digest[20];
     FXSYS_memset(digest, 0, 20);
     CRYPT_SHA1Finish(m_pByteContext, digest);
-    int32_t nLen = FX_Base64EncodeA(digest, 20, NULL);
+    int32_t nLen = Base64EncodeA(digest, 20, NULL);
     FX_CHAR* pBuffer = m_bsChecksum.GetBuffer(nLen);
-    FX_Base64EncodeA(digest, 20, pBuffer);
+    Base64EncodeA(digest, 20, pBuffer);
     m_bsChecksum.ReleaseBuffer(nLen);
     FX_Free(m_pByteContext);
     m_pByteContext = NULL;
   }
 }
 
 CFX_ByteString CXFA_ChecksumContext::GetChecksum() const {
   return m_bsChecksum;
 }
 
 void CXFA_ChecksumContext::Update(const CFX_ByteStringC& bsText) {
   if (m_pByteContext) {
     CRYPT_SHA1Update(m_pByteContext, bsText.raw_str(), bsText.GetLength());
   }
 }