hashes.h

// -*- mode: cpp; mode: fold -*-
// Description                                                          /*{{{*/
/* ######################################################################
 
   Hashes - Simple wrapper around the hash functions
 
   This is just used to make building the methods simpler, this is the
   only interface required..
 
   ##################################################################### */
                                                                        /*}}}*/
#ifndef APTPKG_HASHES_H
#define APTPKG_HASHES_H
 
#include <apt-pkg/macros.h>
 
#ifdef APT_COMPILING_APT
#include <apt-pkg/tagfile-keys.h>
#endif
 
#include <cstring>
#include <string>
#include <string_view>
#include <vector>
 
 
 
class FileFd;
 
// helper class that contains hash function name
// and hash
class APT_PUBLIC HashString
{
 protected:
   std::string Type;
   std::string Hash;
   static const char * _SupportedHashes[10];
 
   // internal helper
   std::string GetHashForFile(std::string filename) const;
 
 public:
   HashString(std::string Type, std::string Hash);
   explicit HashString(std::string_view StringedHashString);  // init from str as "type:hash"
   HashString();
 
   // get hash type used
   std::string HashType() const { return Type; };
   std::string HashValue() const { return Hash; };
 
   // verify the given filename against the currently loaded hash
   bool VerifyFile(std::string filename) const;
 
   // generate a hash string from the given filename
   bool FromFile(std::string filename);
 
 
   // helper
   std::string toStr() const;                    // convert to str as "type:hash"
   bool empty() const;
   bool usable() const;
   bool operator==(HashString const &other) const;
   bool operator!=(HashString const &other) const;
 
   // return the list of hashes we support
   static APT_PURE const char** SupportedHashes();
#ifdef APT_COMPILING_APT
   struct APT_HIDDEN HashSupportInfo {
      std::string_view name;
      pkgTagSection::Key namekey;
      std::string_view chksumsname;
      pkgTagSection::Key chksumskey;
   };
   APT_HIDDEN static std::vector<HashSupportInfo> SupportedHashesInfo();
#endif
};
 
class APT_PUBLIC HashStringList
{
   public:
   HashString const * find(char const * const type) const;
   HashString const * find(std::string const &type) const { return find(type.c_str()); }
 
   unsigned long long FileSize() const;
 
   bool FileSize(unsigned long long const Size);
 
   static APT_PURE bool supported(char const * const type);
   bool push_back(const HashString &hashString);
   size_t size() const { return list.size(); }
 
   bool VerifyFile(std::string filename) const;
 
   bool empty() const { return list.empty(); }
 
   bool usable() const;
 
   typedef std::vector<HashString>::const_iterator const_iterator;
 
   const_iterator begin() const { return list.begin(); }
 
   const_iterator end() const { return list.end(); }
 
   void clear() { list.clear(); }
 
   bool operator==(HashStringList const &other) const;
   bool operator!=(HashStringList const &other) const;
 
   HashStringList() {}
 
   // simplifying API-compatibility constructors
   explicit HashStringList(std::string const &hash) {
      if (hash.empty() == false)
         list.push_back(HashString(hash));
   }
   explicit HashStringList(char const * const hash) {
      if (hash != NULL && hash[0] != '\0')
         list.push_back(HashString(hash));
   }
 
   private:
   std::vector<HashString> list;
};
 
class PrivateHashes;
class APT_PUBLIC Hashes
{
   PrivateHashes * const d;
   public:
   static const int UntilEOF = 0;
 
   bool Add(const unsigned char * const Data, unsigned long long const Size) APT_NONNULL(2);
   inline bool Add(const char * const Data) APT_NONNULL(2)
   {return Add(reinterpret_cast<unsigned char const *>(Data),strlen(Data));};
   inline bool Add(const char *const Data, unsigned long long const Size) APT_NONNULL(2)
   {
      return Add(reinterpret_cast<unsigned char const *>(Data), Size);
   };
   inline bool Add(const unsigned char * const Beg,const unsigned char * const End) APT_NONNULL(2,3)
   {return Add(Beg,End-Beg);};
 
   enum SupportedHashes { MD5SUM = (1 << 0), SHA1SUM = (1 << 1), SHA256SUM = (1 << 2),
      SHA512SUM = (1 << 3) };
   bool AddFD(int const Fd,unsigned long long Size = 0);
   bool AddFD(FileFd &Fd,unsigned long long Size = 0);
 
   HashStringList GetHashStringList();
 
   HashString GetHashString(SupportedHashes hash);
 
   Hashes();
   explicit Hashes(unsigned int const Hashes);
   explicit Hashes(HashStringList const &Hashes);
   virtual ~Hashes();
};
 
#endif