aboutsummaryrefslogtreecommitdiff
path: root/src/hash.cc
blob: 72dcd790c7dc0fd0e94fb77bf7f79c84ec875d6b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
#include <iostream>

extern "C" {
#include "md5.h"
}

#include "hash.hh"
#include "archive.hh"


Hash::Hash()
{
    memset(hash, 0, sizeof(hash));
}


bool Hash::operator == (Hash h2)
{
    for (unsigned int i = 0; i < hashSize; i++)
        if (hash[i] != h2.hash[i]) return false;
    return true;
}


bool Hash::operator != (Hash h2)
{
    return !(*this == h2);
}


Hash::operator string() const
{
    ostringstream str;
    for (unsigned int i = 0; i < hashSize; i++) {
        str.fill('0');
        str.width(2);
        str << hex << (int) hash[i];
    }
    return str.str();
}

    
Hash parseHash(const string & s)
{
    Hash hash;
    if (s.length() != Hash::hashSize * 2)
        throw BadRefError("invalid hash: " + s);
    for (unsigned int i = 0; i < Hash::hashSize; i++) {
        string s2(s, i * 2, 2);
        if (!isxdigit(s2[0]) || !isxdigit(s2[1])) 
            throw BadRefError("invalid hash: " + s);
        istringstream str(s2);
        int n;
        str >> hex >> n;
        hash.hash[i] = n;
    }
    return hash;
}


bool isHash(const string & s)
{
    if (s.length() != 32) return false;
    for (int i = 0; i < 32; i++) {
        char c = s[i];
        if (!((c >= '0' && c <= '9') ||
              (c >= 'a' && c <= 'f')))
            return false;
    }
    return true;
}


Hash hashString(const string & s)
{
    Hash hash;
    md5_buffer(s.c_str(), s.length(), hash.hash);
    return hash;
}


Hash hashFile(const string & fileName)
{
    Hash hash;
    FILE * file = fopen(fileName.c_str(), "rb");
    if (!file)
        throw SysError("file `" + fileName + "' does not exist");
    int err = md5_stream(file, hash.hash);
    fclose(file);
    if (err) throw SysError("cannot hash file " + fileName);
    return hash;
}


struct HashSink : DumpSink
{
    struct md5_ctx ctx;
    virtual void operator ()
        (const unsigned char * data, unsigned int len)
    {
        md5_process_bytes(data, len, &ctx);
    }
};


Hash hashPath(const string & path)
{
    Hash hash;
    HashSink sink;
    md5_init_ctx(&sink.ctx);
    dumpPath(path, sink);
    md5_finish_ctx(&sink.ctx, hash.hash);
    return hash;
}