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    /** sets the filesize hash
 100     *
 101     * @param Size of the file
 102     * @return @see #push_back
 103     */
 104    bool FileSize(unsigned long long const Size);
 105
 106    /** check if the given hash type is supported
 107     *
 108     * @param type to check
 109     * @return true if supported, otherwise false
 110     */
 111    static APT_PURE bool supported(char const * const type);
 112    /** add the given #HashString to the list
 113     *
 114     * @param hashString to add
 115     * @return true if the hash is added because it is supported and
 116     *  not already a different hash of the same type included, otherwise false
 117     */
 118    bool push_back(const HashString &hashString);
 119    /** @return size of the list of HashStrings */
 120    size_t size() const { return list.size(); }
 121
 122    /** take the 'best' hash and verify file with it
 123     *
 124     * @param filename to verify
 125     * @return true if the file matches the hashsum, otherwise false
 126     */
 127    bool VerifyFile(std::string filename) const;
 128
 129    /** is the list empty ?
 130     *
 131     * @return \b true if the list is empty, otherwise \b false
 132     */
 133    bool empty() const { return list.empty(); }
 134
 135    /** has the list at least one good entry
 136     *
 137     * similar to #empty, but handles forced hashes.
 138     *
 139     * @return if no hash is forced, same result as #empty,
 140     * if one is forced \b true if this has is available, \b false otherwise
 141     */
 142    bool usable() const;
 143
 144    typedef std::vector<HashString>::const_iterator const_iterator;
 145
 146    /** iterator to the first element */
 147    const_iterator begin() const { return list.begin(); }
 148
 149    /** iterator to the end element */
 150    const_iterator end() const { return list.end(); }
 151
 152    /** start fresh with a clear list */
 153    void clear() { list.clear(); }
 154
 155    /** compare two HashStringList for similarity.
 156     *
 157     * Two lists are similar if at least one hashtype is in both lists
 158     * and the hashsum matches. All hashes are checked by default,
 159     * if one doesn't match false is returned regardless of how many
 160     * matched before. If a hash is forced, only this hash is compared,
 161     * all others are ignored.
 162     */
 163    bool operator==(HashStringList const &other) const;
 164    bool operator!=(HashStringList const &other) const;
 165
 166    HashStringList() {}
 167
 168    // simplifying API-compatibility constructors
 169    HashStringList(std::string const &hash) {
 170       if (hash.empty() == false)
 171          list.push_back(HashString(hash));
 172    }
 173    HashStringList(char const * const hash) {
 174       if (hash != NULL && hash[0] != '\0')
 175          list.push_back(HashString(hash));
 176    }
 177
 178    private:
 179    std::vector<HashString> list;
 180 };
 181
 182 class PrivateHashes;
 183 class Hashes
 184 {
 185    PrivateHashes * const d;
 186
 187    public:
 188    /* those will disappear in the future as it is hard to add new ones this way.
 189     * Use Add* to build the results and get them via GetHashStringList() instead */
 190    APT_DEPRECATED MD5Summation MD5;
 191    APT_DEPRECATED SHA1Summation SHA1;
 192    APT_DEPRECATED SHA256Summation SHA256;
 193    APT_DEPRECATED SHA512Summation SHA512;
 194
 195    static const int UntilEOF = 0;
 196
 197    bool Add(const unsigned char * const Data, unsigned long long const Size);
 198    APT_DEPRECATED bool Add(const unsigned char * const Data, unsigned long long const Size, unsigned int const Hashes);
 199    inline bool Add(const char * const Data)
 200    {return Add((unsigned char const * const)Data,strlen(Data));};
 201    inline bool Add(const unsigned char * const Beg,const unsigned char * const End)
 202    {return Add(Beg,End-Beg);};
 203
 204    enum SupportedHashes { MD5SUM = (1 << 0), SHA1SUM = (1 << 1), SHA256SUM = (1 << 2),
 205       SHA512SUM = (1 << 3) };
 206    bool AddFD(int const Fd,unsigned long long Size = 0);
 207    APT_DEPRECATED bool AddFD(int const Fd,unsigned long long Size, unsigned int const Hashes);
 208    bool AddFD(FileFd &Fd,unsigned long long Size = 0);
 209    APT_DEPRECATED bool AddFD(FileFd &Fd,unsigned long long Size, unsigned int const Hashes);
 210
 211    HashStringList GetHashStringList();
 212
 213 APT_IGNORE_DEPRECATED_PUSH
 214    /** create a Hashes object to calculate all supported hashes
 215     *
 216     * If ALL is too much, you can limit which Hashes are calculated
 217     * with the following other constructors which mention explicitly
 218     * which hashes to generate. */
 219    Hashes();
 220    /** @param Hashes bitflag composed of #SupportedHashes */
 221    Hashes(unsigned int const Hashes);
 222    /** @param Hashes is a list of hashes */
 223    Hashes(HashStringList const &Hashes);
 224    virtual ~Hashes();
 225 APT_IGNORE_DEPRECATED_POP
 226
 227    private:
 228    APT_HIDDEN APT_CONST inline unsigned int boolsToFlag(bool const addMD5, bool const addSHA1, bool const addSHA256, bool const addSHA512)
 229    {
 230       unsigned int Hashes = ~0;
 231       if (addMD5 == false) Hashes &= ~MD5SUM;
 232       if (addSHA1 == false) Hashes &= ~SHA1SUM;
 233       if (addSHA256 == false) Hashes &= ~SHA256SUM;
 234       if (addSHA512 == false) Hashes &= ~SHA512SUM;
 235       return Hashes;
 236    }
 237
 238    public:
 239 APT_IGNORE_DEPRECATED_PUSH
 240    APT_DEPRECATED bool AddFD(int const Fd, unsigned long long Size, bool const addMD5,
 241          bool const addSHA1, bool const addSHA256, bool const addSHA512) {
 242       return AddFD(Fd, Size, boolsToFlag(addMD5, addSHA1, addSHA256, addSHA512));
 243    };
 244    APT_DEPRECATED bool AddFD(FileFd &Fd, unsigned long long Size, bool const addMD5,
 245          bool const addSHA1, bool const addSHA256, bool const addSHA512) {
 246       return AddFD(Fd, Size, boolsToFlag(addMD5, addSHA1, addSHA256, addSHA512));
 247    };
 248 APT_IGNORE_DEPRECATED_POP
 249 };
 250
 251 #endif