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    APT_DEPRECATED std::string HashType() { return Type; };
  59    APT_DEPRECATED std::string HashValue() { return Hash; };
  60
  61    // verify the given filename against the currently loaded hash
  62    bool VerifyFile(std::string filename) const;
  63
  64    // generate a hash string from the given filename
  65    bool FromFile(std::string filename);
  66
  67
  68    // helper
  69    std::string toStr() const;                    // convert to str as "type:hash"
  70    bool empty() const;
  71    bool operator==(HashString const &other) const;
  72    bool operator!=(HashString const &other) const;
  73
  74    // return the list of hashes we support
  75    static APT_CONST const char** SupportedHashes();
  76 };
  77
  78 class HashStringList
  79 {
  80    public:
  81    /** find best hash if no specific one is requested
  82     *
  83     * @param type of the checksum to return, can be \b NULL
  84     * @return If type is \b NULL (or the empty string) it will
  85     *  return the 'best' hash; otherwise the hash which was
  86     *  specifically requested. If no hash is found \b NULL will be returned.
  87     */
  88    HashString const * find(char const * const type) const;
  89    HashString const * find(std::string const &type) const { return find(type.c_str()); }
  90    /** check if the given hash type is supported
  91     *
  92     * @param type to check
  93     * @return true if supported, otherwise false
  94     */
  95    static APT_PURE bool supported(char const * const type);
  96    /** add the given #HashString to the list
  97     *
  98     * @param hashString to add
  99     * @return true if the hash is added because it is supported and
 100     *  not already a different hash of the same type included, otherwise false
 101     */
 102    bool push_back(const HashString &hashString);
 103    /** @return size of the list of HashStrings */
 104    size_t size() const { return list.size(); }
 105
 106    /** take the 'best' hash and verify file with it
 107     *
 108     * @param filename to verify
 109     * @return true if the file matches the hashsum, otherwise false
 110     */
 111    bool VerifyFile(std::string filename) const;
 112
 113    /** is the list empty ?
 114     *
 115     * @return \b true if the list is empty, otherwise \b false
 116     */
 117    bool empty() const { return list.empty(); }
 118
 119    /** has the list at least one good entry
 120     *
 121     * similar to #empty, but handles forced hashes.
 122     *
 123     * @return if no hash is forced, same result as #empty,
 124     * if one is forced \b true if this has is available, \b false otherwise
 125     */
 126    bool usable() const;
 127
 128    typedef std::vector<HashString>::const_iterator const_iterator;
 129
 130    /** iterator to the first element */
 131    const_iterator begin() const { return list.begin(); }
 132
 133    /** iterator to the end element */
 134    const_iterator end() const { return list.end(); }
 135
 136    /** start fresh with a clear list */
 137    void clear() { list.clear(); }
 138
 139    /** compare two HashStringList for similarity.
 140     *
 141     * Two lists are similar if at least one hashtype is in both lists
 142     * and the hashsum matches. All hashes are checked by default,
 143     * if one doesn't match false is returned regardless of how many
 144     * matched before. If a hash is forced, only this hash is compared,
 145     * all others are ignored.
 146     */
 147    bool operator==(HashStringList const &other) const;
 148    bool operator!=(HashStringList const &other) const;
 149
 150    HashStringList() {}
 151
 152    // simplifying API-compatibility constructors
 153    HashStringList(std::string const &hash) {
 154       if (hash.empty() == false)
 155          list.push_back(HashString(hash));
 156    }
 157    HashStringList(char const * const hash) {
 158       if (hash != NULL && hash[0] != '\0')
 159          list.push_back(HashString(hash));
 160    }
 161
 162    private:
 163    std::vector<HashString> list;
 164 };
 165
 166 class PrivateHashes;
 167 class Hashes
 168 {
 169    PrivateHashes *d;
 170
 171    public:
 172    /* those will disappear in the future as it is hard to add new ones this way.
 173     * Use Add* to build the results and get them via GetHashStringList() instead */
 174    APT_DEPRECATED MD5Summation MD5;
 175    APT_DEPRECATED SHA1Summation SHA1;
 176    APT_DEPRECATED SHA256Summation SHA256;
 177    APT_DEPRECATED SHA512Summation SHA512;
 178
 179    static const int UntilEOF = 0;
 180
 181    bool Add(const unsigned char * const Data, unsigned long long const Size);
 182    APT_DEPRECATED bool Add(const unsigned char * const Data, unsigned long long const Size, unsigned int const Hashes);
 183    inline bool Add(const char * const Data)
 184    {return Add((unsigned char const * const)Data,strlen(Data));};
 185    inline bool Add(const unsigned char * const Beg,const unsigned char * const End)
 186    {return Add(Beg,End-Beg);};
 187
 188    enum SupportedHashes { MD5SUM = (1 << 0), SHA1SUM = (1 << 1), SHA256SUM = (1 << 2),
 189       SHA512SUM = (1 << 3) };
 190    bool AddFD(int const Fd,unsigned long long Size = 0);
 191    APT_DEPRECATED bool AddFD(int const Fd,unsigned long long Size, unsigned int const Hashes);
 192    bool AddFD(FileFd &Fd,unsigned long long Size = 0);
 193    APT_DEPRECATED bool AddFD(FileFd &Fd,unsigned long long Size, unsigned int const Hashes);
 194
 195    HashStringList GetHashStringList();
 196
 197 APT_IGNORE_DEPRECATED_PUSH
 198    /** create a Hashes object to calculate all supported hashes
 199     *
 200     * If ALL is too much, you can limit which Hashes are calculated
 201     * with the following other constructors which mention explicitly
 202     * which hashes to generate. */
 203    Hashes();
 204    /** @param Hashes bitflag composed of #SupportedHashes */
 205    Hashes(unsigned int const Hashes);
 206    /** @param Hashes is a list of hashes */
 207    Hashes(HashStringList const &Hashes);
 208    virtual ~Hashes();
 209 APT_IGNORE_DEPRECATED_POP
 210
 211    private:
 212    APT_HIDDEN APT_CONST inline unsigned int boolsToFlag(bool const addMD5, bool const addSHA1, bool const addSHA256, bool const addSHA512)
 213    {
 214       unsigned int Hashes = ~0;
 215       if (addMD5 == false) Hashes &= ~MD5SUM;
 216       if (addSHA1 == false) Hashes &= ~SHA1SUM;
 217       if (addSHA256 == false) Hashes &= ~SHA256SUM;
 218       if (addSHA512 == false) Hashes &= ~SHA512SUM;
 219       return Hashes;
 220    }
 221
 222    public:
 223 APT_IGNORE_DEPRECATED_PUSH
 224    APT_DEPRECATED bool AddFD(int const Fd, unsigned long long Size, bool const addMD5,
 225          bool const addSHA1, bool const addSHA256, bool const addSHA512) {
 226       return AddFD(Fd, Size, boolsToFlag(addMD5, addSHA1, addSHA256, addSHA512));
 227    };
 228    APT_DEPRECATED bool AddFD(FileFd &Fd, unsigned long long Size, bool const addMD5,
 229          bool const addSHA1, bool const addSHA256, bool const addSHA512) {
 230       return AddFD(Fd, Size, boolsToFlag(addMD5, addSHA1, addSHA256, addSHA512));
 231    };
 232 APT_IGNORE_DEPRECATED_POP
 233 };
 234
 235 #endif