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
  91    /** finds the filesize hash and returns it as number
  92     *
  93     * @return beware: if the size isn't known we return \b 0 here,
  94     * just like we would do for an empty file. If that is a problem
  95     * for you have to get the size manually out of the list.
  96     */
  97    unsigned long long FileSize() const;
  98
  99    /** check if the given hash type is supported
 100     *
 101     * @param type to check
 102     * @return true if supported, otherwise false
 103     */
 104    static APT_PURE bool supported(char const * const type);
 105    /** add the given #HashString to the list
 106     *
 107     * @param hashString to add
 108     * @return true if the hash is added because it is supported and
 109     *  not already a different hash of the same type included, otherwise false
 110     */
 111    bool push_back(const HashString &hashString);
 112    /** @return size of the list of HashStrings */
 113    size_t size() const { return list.size(); }
 114
 115    /** take the 'best' hash and verify file with it
 116     *
 117     * @param filename to verify
 118     * @return true if the file matches the hashsum, otherwise false
 119     */
 120    bool VerifyFile(std::string filename) const;
 121
 122    /** is the list empty ?
 123     *
 124     * @return \b true if the list is empty, otherwise \b false
 125     */
 126    bool empty() const { return list.empty(); }
 127
 128    /** has the list at least one good entry
 129     *
 130     * similar to #empty, but handles forced hashes.
 131     *
 132     * @return if no hash is forced, same result as #empty,
 133     * if one is forced \b true if this has is available, \b false otherwise
 134     */
 135    bool usable() const;
 136
 137    typedef std::vector<HashString>::const_iterator const_iterator;
 138
 139    /** iterator to the first element */
 140    const_iterator begin() const { return list.begin(); }
 141
 142    /** iterator to the end element */
 143    const_iterator end() const { return list.end(); }
 144
 145    /** start fresh with a clear list */
 146    void clear() { list.clear(); }
 147
 148    /** compare two HashStringList for similarity.
 149     *
 150     * Two lists are similar if at least one hashtype is in both lists
 151     * and the hashsum matches. All hashes are checked by default,
 152     * if one doesn't match false is returned regardless of how many
 153     * matched before. If a hash is forced, only this hash is compared,
 154     * all others are ignored.
 155     */
 156    bool operator==(HashStringList const &other) const;
 157    bool operator!=(HashStringList const &other) const;
 158
 159    HashStringList() {}
 160
 161    // simplifying API-compatibility constructors
 162    HashStringList(std::string const &hash) {
 163       if (hash.empty() == false)
 164          list.push_back(HashString(hash));
 165    }
 166    HashStringList(char const * const hash) {
 167       if (hash != NULL && hash[0] != '\0')
 168          list.push_back(HashString(hash));
 169    }
 170
 171    private:
 172    std::vector<HashString> list;
 173 };
 174
 175 class PrivateHashes;
 176 class Hashes
 177 {
 178    PrivateHashes *d;
 179
 180    public:
 181    /* those will disappear in the future as it is hard to add new ones this way.
 182     * Use Add* to build the results and get them via GetHashStringList() instead */
 183    APT_DEPRECATED MD5Summation MD5;
 184    APT_DEPRECATED SHA1Summation SHA1;
 185    APT_DEPRECATED SHA256Summation SHA256;
 186    APT_DEPRECATED SHA512Summation SHA512;
 187
 188    static const int UntilEOF = 0;
 189
 190    bool Add(const unsigned char * const Data, unsigned long long const Size);
 191    APT_DEPRECATED bool Add(const unsigned char * const Data, unsigned long long const Size, unsigned int const Hashes);
 192    inline bool Add(const char * const Data)
 193    {return Add((unsigned char const * const)Data,strlen(Data));};
 194    inline bool Add(const unsigned char * const Beg,const unsigned char * const End)
 195    {return Add(Beg,End-Beg);};
 196
 197    enum SupportedHashes { MD5SUM = (1 << 0), SHA1SUM = (1 << 1), SHA256SUM = (1 << 2),
 198       SHA512SUM = (1 << 3) };
 199    bool AddFD(int const Fd,unsigned long long Size = 0);
 200    APT_DEPRECATED bool AddFD(int const Fd,unsigned long long Size, unsigned int const Hashes);
 201    bool AddFD(FileFd &Fd,unsigned long long Size = 0);
 202    APT_DEPRECATED bool AddFD(FileFd &Fd,unsigned long long Size, unsigned int const Hashes);
 203
 204    HashStringList GetHashStringList();
 205
 206 APT_IGNORE_DEPRECATED_PUSH
 207    /** create a Hashes object to calculate all supported hashes
 208     *
 209     * If ALL is too much, you can limit which Hashes are calculated
 210     * with the following other constructors which mention explicitly
 211     * which hashes to generate. */
 212    Hashes();
 213    /** @param Hashes bitflag composed of #SupportedHashes */
 214    Hashes(unsigned int const Hashes);
 215    /** @param Hashes is a list of hashes */
 216    Hashes(HashStringList const &Hashes);
 217    virtual ~Hashes();
 218 APT_IGNORE_DEPRECATED_POP
 219
 220    private:
 221    APT_HIDDEN APT_CONST inline unsigned int boolsToFlag(bool const addMD5, bool const addSHA1, bool const addSHA256, bool const addSHA512)
 222    {
 223       unsigned int Hashes = ~0;
 224       if (addMD5 == false) Hashes &= ~MD5SUM;
 225       if (addSHA1 == false) Hashes &= ~SHA1SUM;
 226       if (addSHA256 == false) Hashes &= ~SHA256SUM;
 227       if (addSHA512 == false) Hashes &= ~SHA512SUM;
 228       return Hashes;
 229    }
 230
 231    public:
 232 APT_IGNORE_DEPRECATED_PUSH
 233    APT_DEPRECATED bool AddFD(int const Fd, unsigned long long Size, bool const addMD5,
 234          bool const addSHA1, bool const addSHA256, bool const addSHA512) {
 235       return AddFD(Fd, Size, boolsToFlag(addMD5, addSHA1, addSHA256, addSHA512));
 236    };
 237    APT_DEPRECATED bool AddFD(FileFd &Fd, unsigned long long Size, bool const addMD5,
 238          bool const addSHA1, bool const addSHA256, bool const addSHA512) {
 239       return AddFD(Fd, Size, boolsToFlag(addMD5, addSHA1, addSHA256, addSHA512));
 240    };
 241 APT_IGNORE_DEPRECATED_POP
 242 };
 243
 244 #endif