text: // Copyright 2015 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.
  
  #ifndef COMPONENTS_FEEDBACK_ANONYMIZER_TOOL_H_
  #define COMPONENTS_FEEDBACK_ANONYMIZER_TOOL_H_
  
  #include <map>
  #include <memory>
  #include <string>
  #include <vector>
  
  #include "base/macros.h"
  #include "base/memory/ref_counted.h"
  #include "base/sequence_checker.h"
  #include "base/sequenced_task_runner.h"
  
  namespace re2 {
  class RE2;
  }
  
  namespace feedback {
  
  struct CustomPatternWithAlias {
    // A string literal used in anonymized tests. Matches to the |pattern| are
    // replaced with <|alias|: 1>, <|alias|: 2>, ...
    const char* alias;
    // A RE2 regexp used in the replacing logic. Matches will be replaced by the
    // alias reference described above.
    const char* pattern;
  };
  
  class AnonymizerTool {
   public:
    // |first_party_extension_ids| is a null terminated array of all the 1st
    // party extension IDs whose URLs won't be redacted. It is OK to pass null for
    // that value if it's OK to redact those URLs or they won't be present.
    AnonymizerTool(const char* const* first_party_extension_ids);
    ~AnonymizerTool();
  
    // Returns an anonymized version of |input|. PII-sensitive data (such as MAC
    // addresses) in |input| is replaced with unique identifiers.
    // This is an expensive operation. Make sure not to execute this on the UI
    // thread.
    std::string Anonymize(const std::string& input);
  
   private:
    friend class AnonymizerToolTest;
  
    re2::RE2* GetRegExp(const std::string& pattern);
  
    std::string AnonymizeMACAddresses(const std::string& input);
    std::string AnonymizeAndroidAppStoragePaths(const std::string& input);
    std::string AnonymizeHashes(const std::string& input);
    std::string AnonymizeCustomPatterns(std::string input);
    std::string AnonymizeCustomPatternWithContext(
        const std::string& input,
        const CustomPatternWithAlias& pattern);
    std::string AnonymizeCustomPatternWithoutContext(
        const std::string& input,
        const CustomPatternWithAlias& pattern);
  
    // Null-terminated list of first party extension IDs. We need to have this
    // passed into us because we can't refer to the code where these are defined.
    const char* const* first_party_extension_ids_;  // Not owned.
  
    // Map of MAC addresses discovered in anonymized strings to anonymized
    // representations. 11:22:33:44:55:66 gets anonymized to
    // [MAC OUI=11:22:33 IFACE=1], where the first three bytes (OUI) represent the
    // manufacturer. The IFACE value is incremented for each newly discovered MAC
    // address.
    std::map<std::string, std::string> mac_addresses_;
  
    // Map of hashes discovered in anonymized strings to anonymized
    // representations. Hexadecimal strings of length 32, 40 and 64 are considered
    // to be hashes. 11223344556677889900aabbccddeeff gets anonymized to
    // <HASH:1122 1> where the first 2 bytes of the hash are retained as-is and
    // the value after that is incremented for each newly discovered hash.
    std::map<std::string, std::string> hashes_;
  
    // Like mac addresses, identifiers in custom patterns are anonymized.
    // custom_patterns_with_context_["alias"] contains a map of original
    // identifier to anonymized identifier for custom pattern with the given
    // "alias".  We key on alias to allow different patterns to use the same
    // replacement maps.
    std::map<std::string, std::map<std::string, std::string>>
        custom_patterns_with_context_;
    std::map<std::string, std::map<std::string, std::string>>
        custom_patterns_without_context_;
  
    // Cache to prevent the repeated compilation of the same regular expression
    // pattern. Key is the string representation of the RegEx.
    std::map<std::string, std::unique_ptr<re2::RE2>> regexp_cache_;
  
    SEQUENCE_CHECKER(sequence_checker_);
  
    DISALLOW_COPY_AND_ASSIGN(AnonymizerTool);
  };
  
  // A container for a AnonymizerTool that is thread-safely ref-countable.
  // This is useful for a class that wants to post an async anonymization task
  // to a background sequence runner and not deal with its own life-cycle ending
  // while the AnonymizerTool is busy on another sequence.
  class AnonymizerToolContainer
      : public base::RefCountedThreadSafe<AnonymizerToolContainer> {
   public:
    explicit AnonymizerToolContainer(
        scoped_refptr<base::SequencedTaskRunner> task_runner,
        const char* const* first_party_extension_ids);
  
    // Returns a pointer to the instance of this anonymier. May only be called
    // on |task_runner_|.
    AnonymizerTool* Get();
  
   private:
    friend class base::RefCountedThreadSafe<AnonymizerToolContainer>;
    ~AnonymizerToolContainer();
  
    std::unique_ptr<AnonymizerTool> anonymizer_;
    scoped_refptr<base::SequencedTaskRunner> task_runner_;
  };
  
  }  // namespace feedback
  
  #endif  // COMPONENTS_FEEDBACK_ANONYMIZER_TOOL_H_
  