xbmc/utils/Digest.h

   1 /*
   2  *  Copyright (C) 2018 Team Kodi
   3  *  This file is part of Kodi - https://kodi.tv
   4  *
   5  *  SPDX-License-Identifier: GPL-2.0-or-later
   6  *  See LICENSES/README.md for more information.
   7  */
   8
   9 #pragma once
  10
  11 #include "StringUtils.h"
  12
  13 #include <iostream>
  14 #include <memory>
  15 #include <stdexcept>
  16 #include <string>
  17
  18 #include <openssl/evp.h>
  19
  20 namespace KODI
  21 {
  22 namespace UTILITY
  23 {
  24
  25 /**
  26  * Utility class for calculating message digests/hashes, currently using OpenSSL
  27  */
  28 class CDigest
  29 {
  30 public:
  31   enum class Type
  32   {
  33     MD5,
  34     SHA1,
  35     SHA256,
  36     SHA512,
  37     INVALID
  38   };
  39
  40   /**
  41    * Convert type enumeration value to lower-case string representation
  42    */
  43   static std::string TypeToString(Type type);
  44   /**
  45    * Convert digest type string representation to enumeration value
  46    */
  47   static Type TypeFromString(std::string const& type);
  48
  49   /**
  50    * Create a digest calculation object
  51    */
  52   CDigest(Type type);
  53   /**
  54    * Update digest with data
  55    *
  56    * Cannot be called after \ref Finalize has been called
  57    */
  58   void Update(std::string const& data);
  59   /**
  60    * Update digest with data
  61    *
  62    * Cannot be called after \ref Finalize has been called
  63    */
  64   void Update(void const* data, std::size_t size);
  65   /**
  66    * Finalize and return the digest
  67    *
  68    * The digest object cannot be used any more after this function
  69    * has been called.
  70    *
  71    * \return digest value as string in lower-case hexadecimal notation
  72    */
  73   std::string Finalize();
  74   /**
  75    * Finalize and return the digest
  76    *
  77    * The digest object cannot be used any more after this
  78    * function has been called.
  79    *
  80    * \return digest value as binary std::string
  81    */
  82   std::string FinalizeRaw();
  83
  84   /**
  85    * Calculate message digest
  86    */
  87   static std::string Calculate(Type type, std::string const& data);
  88   /**
  89    * Calculate message digest
  90    */
  91   static std::string Calculate(Type type, void const* data, std::size_t size);
  92
  93 private:
  94   struct MdCtxDeleter
  95   {
  96     void operator()(EVP_MD_CTX* context);
  97   };
  98
  99   bool m_finalized{false};
 100   std::unique_ptr<EVP_MD_CTX, MdCtxDeleter> m_context;
 101   EVP_MD const* m_md;
 102 };
 103
 104 struct TypedDigest
 105 {
 106   CDigest::Type type{CDigest::Type::INVALID};
 107   std::string value;
 108
 109   TypedDigest() = default;
 110
 111   TypedDigest(CDigest::Type type, std::string const& value)
 112   : type(type), value(value)
 113   {}
 114
 115   bool Empty() const
 116   {
 117     return (type == CDigest::Type::INVALID || value.empty());
 118   }
 119 };
 120
 121 inline bool operator==(TypedDigest const& left, TypedDigest const& right)
 122 {
 123   if (left.type != right.type)
 124   {
 125     throw std::logic_error("Cannot compare digests of different type");
 126   }
 127   return StringUtils::EqualsNoCase(left.value, right.value);
 128 }
 129
 130 inline bool operator!=(TypedDigest const& left, TypedDigest const& right)
 131 {
 132   return !(left == right);
 133 }
 134
 135 std::ostream& operator<<(std::ostream& os, TypedDigest const& digest);
 136
 137 }
 138 }