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    /** has the list at least one good entry
 118     *
 119     * similar to #empty, but handles forced hashes.
 120     *
 121     * @return if no hash is forced, same result as #empty,
 122     * if one is forced \b true if this has is available, \b false otherwise
 123     */
 124    bool usable() const;
 125
 126    typedef std::vector<HashString>::const_iterator const_iterator;
 127
 128    /** iterator to the first element */
 129    const_iterator begin() const { return list.begin(); }
 130
 131    /** iterator to the end element */
 132    const_iterator end() const { return list.end(); }
 133
 134    /** start fresh with a clear list */
 135    void clear() { list.clear(); }
 136
 137    /** compare two HashStringList for similarity.
 138     *
 139     * Two lists are similar if at least one hashtype is in both lists
 140     * and the hashsum matches. All hashes are checked by default,
 141     * if one doesn't match false is returned regardless of how many
 142     * matched before. If a hash is forced, only this hash is compared,
 143     * all others are ignored.
 144     */
 145    bool operator==(HashStringList const &other) const;
 146    bool operator!=(HashStringList const &other) const;
 147
 148    HashStringList() {}
 149
 150    // simplifying API-compatibility constructors
 151    HashStringList(std::string const &hash) {
 152       if (hash.empty() == false)
 153          list.push_back(HashString(hash));
 154    }
 155    HashStringList(char const * const hash) {
 156       if (hash != NULL && hash[0] != '\0')
 157          list.push_back(HashString(hash));
 158    }
 159
 160    private:
 161    std::vector<HashString> list;
 162 };
 163
 164 class PrivateHashes;
 165 class Hashes
 166 {
 167    PrivateHashes *d;
 168
 169    public:
 170    /* those will disappear in the future as it is hard to add new ones this way.
 171     * Use Add* to build the results and get them via GetHashStringList() instead */
 172    APT_DEPRECATED MD5Summation MD5;
 173    APT_DEPRECATED SHA1Summation SHA1;
 174    APT_DEPRECATED SHA256Summation SHA256;
 175    APT_DEPRECATED SHA512Summation SHA512;
 176
 177    static const int UntilEOF = 0;
 178
 179    bool Add(const unsigned char * const Data, unsigned long long const Size, unsigned int const Hashes = ~0);
 180    inline bool Add(const char * const Data)
 181    {return Add((unsigned char const * const)Data,strlen(Data));};
 182    inline bool Add(const unsigned char * const Beg,const unsigned char * const End)
 183    {return Add(Beg,End-Beg);};
 184
 185    enum SupportedHashes { MD5SUM = (1 << 0), SHA1SUM = (1 << 1), SHA256SUM = (1 << 2),
 186       SHA512SUM = (1 << 3) };
 187    bool AddFD(int const Fd,unsigned long long Size = 0, unsigned int const Hashes = ~0);
 188    bool AddFD(FileFd &Fd,unsigned long long Size = 0, unsigned int const Hashes = ~0);
 189
 190    HashStringList GetHashStringList();
 191
 192 APT_IGNORE_DEPRECATED_PUSH
 193    Hashes();
 194    virtual ~Hashes();
 195 APT_IGNORE_DEPRECATED_POP
 196
 197    private:
 198    APT_HIDDEN APT_CONST inline unsigned int boolsToFlag(bool const addMD5, bool const addSHA1, bool const addSHA256, bool const addSHA512)
 199    {
 200       unsigned int Hashes = ~0;
 201       if (addMD5 == false) Hashes &= ~MD5SUM;
 202       if (addSHA1 == false) Hashes &= ~SHA1SUM;
 203       if (addSHA256 == false) Hashes &= ~SHA256SUM;
 204       if (addSHA512 == false) Hashes &= ~SHA512SUM;
 205       return Hashes;
 206    }
 207
 208    public:
 209    APT_DEPRECATED bool AddFD(int const Fd, unsigned long long Size, bool const addMD5,
 210          bool const addSHA1, bool const addSHA256, bool const addSHA512) {
 211       return AddFD(Fd, Size, boolsToFlag(addMD5, addSHA1, addSHA256, addSHA512));
 212    };
 213
 214    APT_DEPRECATED bool AddFD(FileFd &Fd, unsigned long long Size, bool const addMD5,
 215          bool const addSHA1, bool const addSHA256, bool const addSHA512) {
 216       return AddFD(Fd, Size, boolsToFlag(addMD5, addSHA1, addSHA256, addSHA512));
 217    };
 218 };
 219
 220 #endif