Add support to sha256 hash the downloaded file....

chrome/browser/download/base_file.cc

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/download/base_file.h"
 
 #include "base/file_util.h"
 #include "base/logging.h"
+#include "base/string_number_conversions.h"
+#include "base/string_util.h"
 #include "base/stringprintf.h"
+#include "base/third_party/nss/blapi.h"
+#include "base/third_party/nss/sha256.h"
 #include "net/base/file_stream.h"
 #include "net/base/net_errors.h"
 #include "chrome/browser/browser_thread.h"
 #include "chrome/browser/download/download_util.h"
 
 #if defined(OS_WIN)
 #include "app/win/win_util.h"
 #include "chrome/common/win_safe_util.h"
 #elif defined(OS_MACOSX)
 #include "chrome/browser/ui/cocoa/file_metadata.h"
 #endif
 
 BaseFile::BaseFile(const FilePath& full_path,
                    const GURL& source_url,
                    const GURL& referrer_url,
                    int64 received_bytes,
-                   const linked_ptr<net::FileStream>& file_stream)
+                   const linked_ptr<net::FileStream>& file_stream,
+                   bool calculate_hash)
     : full_path_(full_path),
       path_renamed_(false),
       source_url_(source_url),
       referrer_url_(referrer_url),
       file_stream_(file_stream),
       bytes_so_far_(received_bytes),
-      power_save_blocker_(true) {
+      power_save_blocker_(true),
+      calculate_hash_(calculate_hash),
+      sha_context_(NULL) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
 }
 
 BaseFile::~BaseFile() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
   if (in_progress())
     Cancel();
   Close();
 }
 
 bool BaseFile::Initialize() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+
+  if (calculate_hash_) {
+    sha_context_.reset(new SHA256Context);
+    SHA256_Begin(sha_context_.get());
+  }
+
   if (!full_path_.empty() ||
       download_util::CreateTemporaryFileForDownload(&full_path_))
     return Open();
   return false;
 }
 
 bool BaseFile::AppendDataToFile(const char* data, size_t data_len) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
 
   if (!file_stream_.get())
     return false;
 
   // TODO(phajdan.jr): get rid of this check.
   if (data_len == 0)
     return true;
 
+  if (calculate_hash_) {
+    SHA256_Update(sha_context_.get(),
+                  reinterpret_cast<const unsigned char*>(data),
+                  data_len);
+  }
+
   bytes_so_far_ += data_len;
 
   // TODO(phajdan.jr): handle errors on file writes. http://crbug.com/58355
   size_t written = file_stream_->Write(data, data_len, NULL);
   return (written == data_len);
 }
 
 bool BaseFile::Rename(const FilePath& new_path, bool is_final_rename) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
 
@@ skipping 61 matching lines @@
 void BaseFile::Cancel() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
   Close();
   if (!full_path_.empty())
     file_util::Delete(full_path_, false);
 }
 
 void BaseFile::Finish() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
   Close();
+  if (calculate_hash_) {
+    SHA256_End(sha_context_.get(), sha256_hash_, NULL, kSha256HashLen_);
+  }
+}
+
+bool BaseFile::GetSha256Hash(std::string* hash) {
+  if (!calculate_hash_)
+    return false;
+  *hash =
+      StringToLowerASCII(base::HexEncode(sha256_hash_, sizeof(sha256_hash_)));
+  return true;
 }
 
 void BaseFile::AnnotateWithSourceInformation() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
 #if defined(OS_WIN)
   // Sets the Zone to tell Windows that this file comes from the internet.
   // We ignore the return value because a failure is not fatal.
   win_util::SetInternetZoneIdentifier(full_path_);
 #elif defined(OS_MACOSX)
   file_metadata::AddQuarantineMetadataToFile(full_path_, source_url_,
@@ skipping 42 matching lines @@
     file_stream_->Close();
     file_stream_.reset();
   }
 }
 
 std::string BaseFile::DebugString() const {
   return base::StringPrintf("{ source_url_ = \"%s\" full_path_ = \"%s\" }",
                             source_url_.spec().c_str(),
                             full_path_.value().c_str());
 }