apt-pkg/contrib/hashes.h

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: hashes.h,v 1.2 2001/03/11 05:30:20 jgg Exp $
   4 /* ######################################################################
   5
   6    Hashes - Simple wrapper around the hash functions
   7
   8    This is just used to make building the methods simpler, this is the
   9    only interface required..
  10
  11    ##################################################################### */
  12                                                                         /*}}}*/
  13 #ifndef APTPKG_HASHES_H
  14 #define APTPKG_HASHES_H
  15
  16
  17 #include <apt-pkg/md5.h>
  18 #include <apt-pkg/sha1.h>
  19 #include <apt-pkg/sha2.h>
  20 #include <apt-pkg/macros.h>
  21
  22 #include <cstring>
  23 #include <string>
  24
  25 #ifndef APT_8_CLEANER_HEADERS
  26 using std::min;
  27 using std::vector;
  28 #endif
  29 #ifndef APT_10_CLEANER_HEADERS
  30 #include <apt-pkg/fileutl.h>
  31 #include <algorithm>
  32 #include <vector>
  33 #endif
  34
  35
  36 class FileFd;
  37
  38 // helper class that contains hash function name
  39 // and hash
  40 class HashString
  41 {
  42  protected:
  43    std::string Type;
  44    std::string Hash;
  45    static const char * _SupportedHashes[10];
  46
  47    // internal helper
  48    std::string GetHashForFile(std::string filename) const;
  49
  50  public:
  51    HashString(std::string Type, std::string Hash);
  52    HashString(std::string StringedHashString);  // init from str as "type:hash"
  53    HashString();
  54
  55    // get hash type used
  56    std::string HashType() const { return Type; };
  57    std::string HashValue() const { return Hash; };
  58
  59    // verify the given filename against the currently loaded hash
  60    bool VerifyFile(std::string filename) const;
  61
  62    // generate a hash string from the given filename
  63    bool FromFile(std::string filename);
  64
  65
  66    // helper
  67    std::string toStr() const;                    // convert to str as "type:hash"
  68    bool empty() const;
  69    bool operator==(HashString const &other) const;
  70    bool operator!=(HashString const &other) const;
  71
  72    // return the list of hashes we support
  73    static APT_CONST const char** SupportedHashes();
  74 };
  75
  76 class HashStringList
  77 {
  78    public:
  79    /** find best hash if no specific one is requested
  80     *
  81     * @param type of the checksum to return, can be \b NULL
  82     * @return If type is \b NULL (or the empty string) it will
  83     *  return the 'best' hash; otherwise the hash which was
  84     *  specifically requested. If no hash is found \b NULL will be returned.
  85     */
  86    HashString const * find(char const * const type) const;
  87    HashString const * find(std::string const &type) const { return find(type.c_str()); }
  88    /** check if the given hash type is supported
  89     *
  90     * @param type to check
  91     * @return true if supported, otherwise false
  92     */
  93    static APT_PURE bool supported(char const * const type);
  94    /** add the given #HashString to the list
  95     *
  96     * @param hashString to add
  97     * @return true if the hash is added because it is supported and
  98     *  not already a different hash of the same type included, otherwise false
  99     */
 100    bool push_back(const HashString &hashString);
 101    /** @return size of the list of HashStrings */
 102    size_t size() const { return list.size(); }
 103
 104    /** take the 'best' hash and verify file with it
 105     *
 106     * @param filename to verify
 107     * @return true if the file matches the hashsum, otherwise false
 108     */
 109    bool VerifyFile(std::string filename) const;
 110
 111    /** is the list empty ?
 112     *
 113     * @return \b true if the list is empty, otherwise \b false
 114     */
 115    bool empty() const { return list.empty(); }
 116
 117    typedef std::vector<HashString>::const_iterator const_iterator;
 118
 119    /** iterator to the first element */
 120    const_iterator begin() const { return list.begin(); }
 121
 122    /** iterator to the end element */
 123    const_iterator end() const { return list.end(); }
 124
 125    /** start fresh with a clear list */
 126    void clear() { list.clear(); }
 127
 128    /** compare two HashStringList for similarity.
 129     *
 130     * Two lists are similar if at least one hashtype is in both lists
 131     * and the hashsum matches. All hashes are checked, if one doesn't
 132     * match false is returned regardless of how many matched before.
 133     */
 134    bool operator==(HashStringList const &other) const;
 135    bool operator!=(HashStringList const &other) const;
 136
 137    HashStringList() {}
 138
 139    // simplifying API-compatibility constructors
 140    HashStringList(std::string const &hash) {
 141       if (hash.empty() == false)
 142          list.push_back(HashString(hash));
 143    }
 144    HashStringList(char const * const hash) {
 145       if (hash != NULL && hash[0] != '\0')
 146          list.push_back(HashString(hash));
 147    }
 148
 149    private:
 150    std::vector<HashString> list;
 151 };
 152
 153 class Hashes
 154 {
 155    public:
 156
 157    MD5Summation MD5;
 158    SHA1Summation SHA1;
 159    SHA256Summation SHA256;
 160    SHA512Summation SHA512;
 161
 162    static const int UntilEOF = 0;
 163
 164    inline bool Add(const unsigned char *Data,unsigned long long Size)
 165    {
 166       return MD5.Add(Data,Size) && SHA1.Add(Data,Size) && SHA256.Add(Data,Size) && SHA512.Add(Data,Size);
 167    };
 168    inline bool Add(const char *Data) {return Add((unsigned char const *)Data,strlen(Data));};
 169    inline bool AddFD(int const Fd,unsigned long long Size = 0)
 170    { return AddFD(Fd, Size, true, true, true, true); };
 171    bool AddFD(int const Fd, unsigned long long Size, bool const addMD5,
 172               bool const addSHA1, bool const addSHA256, bool const addSHA512);
 173    inline bool AddFD(FileFd &Fd,unsigned long long Size = 0)
 174    { return AddFD(Fd, Size, true, true, true, true); };
 175    bool AddFD(FileFd &Fd, unsigned long long Size, bool const addMD5,
 176               bool const addSHA1, bool const addSHA256, bool const addSHA512);
 177    inline bool Add(const unsigned char *Beg,const unsigned char *End)
 178                   {return Add(Beg,End-Beg);};
 179 };
 180
 181 #endif