305 lines
8.1 KiB
C++
305 lines
8.1 KiB
C++
/*
|
|
|
|
Copyright (c) 2003-2013, Arvid Norberg
|
|
All rights reserved.
|
|
|
|
Redistribution and use in source and binary forms, with or without
|
|
modification, are permitted provided that the following conditions
|
|
are met:
|
|
|
|
* Redistributions of source code must retain the above copyright
|
|
notice, this list of conditions and the following disclaimer.
|
|
* Redistributions in binary form must reproduce the above copyright
|
|
notice, this list of conditions and the following disclaimer in
|
|
the documentation and/or other materials provided with the distribution.
|
|
* Neither the name of the author nor the names of its
|
|
contributors may be used to endorse or promote products derived
|
|
from this software without specific prior written permission.
|
|
|
|
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
|
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
|
|
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
POSSIBILITY OF SUCH DAMAGE.
|
|
|
|
*/
|
|
|
|
#ifndef TORRENT_SHA1_HASH_HPP_INCLUDED
|
|
#define TORRENT_SHA1_HASH_HPP_INCLUDED
|
|
|
|
#include <cctype>
|
|
#include <algorithm>
|
|
#include <string>
|
|
#include <cstring>
|
|
|
|
#include "libtorrent/config.hpp"
|
|
#include "libtorrent/assert.hpp"
|
|
|
|
#if TORRENT_USE_IOSTREAM
|
|
#include "libtorrent/escape_string.hpp" // to_hex, from_hex
|
|
#include <iostream>
|
|
#include <iomanip>
|
|
#endif
|
|
|
|
#ifdef max
|
|
#undef max
|
|
#endif
|
|
|
|
#ifdef min
|
|
#undef min
|
|
#endif
|
|
|
|
namespace libtorrent
|
|
{
|
|
|
|
// This type holds a SHA-1 digest or any other kind of 20 byte
|
|
// sequence. It implements a number of convenience functions, such
|
|
// as bit operations, comparison operators etc.
|
|
//
|
|
// In libtorrent it is primarily used to hold info-hashes, piece-hashes,
|
|
// peer IDs, node IDs etc.
|
|
class TORRENT_EXPORT sha1_hash
|
|
{
|
|
enum { number_size = 20 };
|
|
public:
|
|
// the number of bytes of the number
|
|
static const int size = number_size;
|
|
|
|
// constructs an all-sero sha1-hash
|
|
sha1_hash() { clear(); }
|
|
|
|
// returns an all-F sha1-hash. i.e. the maximum value
|
|
// representable by a 160 bit number (20 bytes). This is
|
|
// a static member function.
|
|
static sha1_hash max()
|
|
{
|
|
sha1_hash ret;
|
|
memset(ret.m_number, 0xff, size);
|
|
return ret;
|
|
}
|
|
|
|
// returns an all-zero sha1-hash. i.e. the minimum value
|
|
// representable by a 160 bit number (20 bytes). This is
|
|
// a static member function.
|
|
static sha1_hash min()
|
|
{
|
|
sha1_hash ret;
|
|
memset(ret.m_number, 0, size);
|
|
return ret;
|
|
}
|
|
|
|
// copies 20 bytes from the pointer provided, into the sha1-hash.
|
|
// The passed in string MUST be at least 20 bytes. NULL terminators
|
|
// are ignored, ``s`` is treated like a raw memory buffer.
|
|
explicit sha1_hash(char const* s)
|
|
{
|
|
if (s == 0) clear();
|
|
else std::memcpy(m_number, s, size);
|
|
}
|
|
explicit sha1_hash(std::string const& s)
|
|
{
|
|
TORRENT_ASSERT(s.size() >= 20);
|
|
int sl = int(s.size()) < size ? int(s.size()) : size;
|
|
std::memcpy(m_number, s.c_str(), sl);
|
|
}
|
|
void assign(std::string const& s)
|
|
{
|
|
TORRENT_ASSERT(s.size() >= 20);
|
|
int sl = int(s.size()) < size ? int(s.size()) : size;
|
|
std::memcpy(m_number, s.c_str(), sl);
|
|
}
|
|
void assign(char const* str) { std::memcpy(m_number, str, size); }
|
|
|
|
// set the sha1-hash to all zeroes.
|
|
void clear() { std::memset(m_number, 0, number_size); }
|
|
|
|
// return true if the sha1-hash is all zero.
|
|
bool is_all_zeros() const
|
|
{
|
|
for (const unsigned char* i = m_number; i < m_number+number_size; ++i)
|
|
if (*i != 0) return false;
|
|
return true;
|
|
}
|
|
|
|
// shift left ``n`` bits.
|
|
sha1_hash& operator<<=(int n)
|
|
{
|
|
TORRENT_ASSERT(n >= 0);
|
|
int num_bytes = n / 8;
|
|
if (num_bytes >= number_size)
|
|
{
|
|
std::memset(m_number, 0, number_size);
|
|
return *this;
|
|
}
|
|
|
|
if (num_bytes > 0)
|
|
{
|
|
std::memmove(m_number, m_number + num_bytes, number_size - num_bytes);
|
|
std::memset(m_number + number_size - num_bytes, 0, num_bytes);
|
|
n -= num_bytes * 8;
|
|
}
|
|
if (n > 0)
|
|
{
|
|
for (int i = 0; i < number_size - 1; ++i)
|
|
{
|
|
m_number[i] <<= n;
|
|
m_number[i] |= m_number[i+1] >> (8 - n);
|
|
}
|
|
m_number[number_size-1] <<= n;
|
|
}
|
|
return *this;
|
|
}
|
|
|
|
// shift r ``n`` bits.
|
|
sha1_hash& operator>>=(int n)
|
|
{
|
|
TORRENT_ASSERT(n >= 0);
|
|
int num_bytes = n / 8;
|
|
if (num_bytes >= number_size)
|
|
{
|
|
std::memset(m_number, 0, number_size);
|
|
return *this;
|
|
}
|
|
if (num_bytes > 0)
|
|
{
|
|
std::memmove(m_number + num_bytes, m_number, number_size - num_bytes);
|
|
std::memset(m_number, 0, num_bytes);
|
|
n -= num_bytes * 8;
|
|
}
|
|
if (n > 0)
|
|
{
|
|
for (int i = number_size - 1; i > 0; --i)
|
|
{
|
|
m_number[i] >>= n;
|
|
m_number[i] |= m_number[i-1] << (8 - n);
|
|
}
|
|
m_number[0] >>= n;
|
|
}
|
|
return *this;
|
|
}
|
|
|
|
// standard comparison operators
|
|
bool operator==(sha1_hash const& n) const
|
|
{
|
|
return std::equal(n.m_number, n.m_number+number_size, m_number);
|
|
}
|
|
|
|
bool operator!=(sha1_hash const& n) const
|
|
{
|
|
return !std::equal(n.m_number, n.m_number+number_size, m_number);
|
|
}
|
|
bool operator<(sha1_hash const& n) const
|
|
{
|
|
for (int i = 0; i < number_size; ++i)
|
|
{
|
|
if (m_number[i] < n.m_number[i]) return true;
|
|
if (m_number[i] > n.m_number[i]) return false;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
// negate every bit in the sha1-hash
|
|
sha1_hash operator~()
|
|
{
|
|
sha1_hash ret;
|
|
for (int i = 0; i< number_size; ++i)
|
|
ret.m_number[i] = ~m_number[i];
|
|
return ret;
|
|
}
|
|
|
|
// bit-wise XOR of the two sha1-hash.
|
|
sha1_hash operator^(sha1_hash const& n) const
|
|
{
|
|
sha1_hash ret = *this;
|
|
ret ^= n;
|
|
return ret;
|
|
}
|
|
sha1_hash& operator^=(sha1_hash const& n)
|
|
{
|
|
for (int i = 0; i< number_size; ++i)
|
|
m_number[i] ^= n.m_number[i];
|
|
return *this;
|
|
}
|
|
|
|
// bit-wise AND of the two sha1-hash.
|
|
sha1_hash operator&(sha1_hash const& n) const
|
|
{
|
|
sha1_hash ret = *this;
|
|
ret &= n;
|
|
return ret;
|
|
}
|
|
sha1_hash& operator&=(sha1_hash const& n)
|
|
{
|
|
for (int i = 0; i< number_size; ++i)
|
|
m_number[i] &= n.m_number[i];
|
|
return *this;
|
|
}
|
|
|
|
// bit-wise OR of the two sha1-hash.
|
|
sha1_hash& operator|=(sha1_hash const& n)
|
|
{
|
|
for (int i = 0; i< number_size; ++i)
|
|
m_number[i] |= n.m_number[i];
|
|
return *this;
|
|
}
|
|
|
|
// accessors for specific bytes
|
|
unsigned char& operator[](int i)
|
|
{ TORRENT_ASSERT(i >= 0 && i < number_size); return m_number[i]; }
|
|
unsigned char const& operator[](int i) const
|
|
{ TORRENT_ASSERT(i >= 0 && i < number_size); return m_number[i]; }
|
|
|
|
typedef const unsigned char* const_iterator;
|
|
typedef unsigned char* iterator;
|
|
|
|
// start and end iterators for the hash. The value type
|
|
// of these iterators is ``unsigned char``.
|
|
const_iterator begin() const { return m_number; }
|
|
const_iterator end() const { return m_number+number_size; }
|
|
iterator begin() { return m_number; }
|
|
iterator end() { return m_number+number_size; }
|
|
|
|
// return a copy of the 20 bytes representing the sha1-hash as a std::string.
|
|
// It's still a binary string with 20 binary characters.
|
|
std::string to_string() const
|
|
{ return std::string((char const*)&m_number[0], number_size); }
|
|
|
|
private:
|
|
|
|
unsigned char m_number[number_size];
|
|
|
|
};
|
|
|
|
typedef sha1_hash peer_id;
|
|
|
|
#if TORRENT_USE_IOSTREAM
|
|
|
|
// print a sha1_hash object to an ostream as 40 hexadecimal digits
|
|
inline std::ostream& operator<<(std::ostream& os, sha1_hash const& peer)
|
|
{
|
|
char out[41];
|
|
to_hex((char const*)&peer[0], sha1_hash::size, out);
|
|
return os << out;
|
|
}
|
|
|
|
// read 40 hexadecimal digits from an istream into a sha1_hash
|
|
inline std::istream& operator>>(std::istream& is, sha1_hash& peer)
|
|
{
|
|
char hex[40];
|
|
is.read(hex, 40);
|
|
if (!from_hex(hex, 40, (char*)&peer[0]))
|
|
is.setstate(std::ios_base::failbit);
|
|
return is;
|
|
}
|
|
#endif // TORRENT_USE_IOSTREAM
|
|
}
|
|
|
|
#endif // TORRENT_PEER_ID_HPP_INCLUDED
|
|
|