Chris@16: // boost/uuid/sha1.hpp header file  ----------------------------------------------//
Chris@16: 
Chris@16: // Copyright 2007 Andy Tompkins.
Chris@16: // Distributed under the Boost Software License, Version 1.0. (See
Chris@16: // accompanying file LICENSE_1_0.txt or copy at
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: // Revision History
Chris@16: //  29 May 2007 - Initial Revision
Chris@16: //  25 Feb 2008 - moved to namespace boost::uuids::detail
Chris@16: //  10 Jan 2012 - can now handle the full size of messages (2^64 - 1 bits)
Chris@16: 
Chris@16: // This is a byte oriented implementation
Chris@16: 
Chris@16: #ifndef BOOST_UUID_SHA1_H
Chris@16: #define BOOST_UUID_SHA1_H
Chris@16: 
Chris@16: #include <boost/static_assert.hpp>
Chris@16: #include <stdexcept>
Chris@16: #include <boost/throw_exception.hpp>
Chris@16: #include <cstddef>
Chris@16: #include <string>
Chris@16: 
Chris@16: #ifdef BOOST_NO_STDC_NAMESPACE
Chris@16: namespace std {
Chris@16:     using ::size_t;
Chris@16: } // namespace std
Chris@16: #endif
Chris@16: 
Chris@16: namespace boost {
Chris@16: namespace uuids {
Chris@16: namespace detail {
Chris@16: 
Chris@16: BOOST_STATIC_ASSERT(sizeof(unsigned char)*8 == 8);
Chris@16: BOOST_STATIC_ASSERT(sizeof(unsigned int)*8 == 32);
Chris@16: 
Chris@16: inline unsigned int left_rotate(unsigned int x, std::size_t n)
Chris@16: {
Chris@16:     return (x<<n) ^ (x>> (32-n));
Chris@16: }
Chris@16: 
Chris@16: class sha1
Chris@16: {
Chris@16: public:
Chris@16:     typedef unsigned int(&digest_type)[5];
Chris@16: public:
Chris@16:     sha1();
Chris@16: 
Chris@16:     void reset();
Chris@16: 
Chris@16:     void process_byte(unsigned char byte);
Chris@16:     void process_block(void const* bytes_begin, void const* bytes_end);
Chris@16:     void process_bytes(void const* buffer, std::size_t byte_count);
Chris@16: 
Chris@16:     void get_digest(digest_type digest);
Chris@16: 
Chris@16: private:
Chris@16:     void process_block();
Chris@16:     void process_byte_impl(unsigned char byte);
Chris@16: 
Chris@16: private:
Chris@16:     unsigned int h_[5];
Chris@16: 
Chris@16:     unsigned char block_[64];
Chris@16: 
Chris@16:     std::size_t block_byte_index_;
Chris@16:     std::size_t bit_count_low;
Chris@16:     std::size_t bit_count_high;
Chris@16: };
Chris@16: 
Chris@16: inline sha1::sha1()
Chris@16: {
Chris@16:     reset();
Chris@16: }
Chris@16: 
Chris@16: inline void sha1::reset()
Chris@16: {
Chris@16:     h_[0] = 0x67452301;
Chris@16:     h_[1] = 0xEFCDAB89;
Chris@16:     h_[2] = 0x98BADCFE;
Chris@16:     h_[3] = 0x10325476;
Chris@16:     h_[4] = 0xC3D2E1F0;
Chris@16: 
Chris@16:     block_byte_index_ = 0;
Chris@16:     bit_count_low = 0;
Chris@16:     bit_count_high = 0;
Chris@16: }
Chris@16: 
Chris@16: inline void sha1::process_byte(unsigned char byte)
Chris@16: {
Chris@16:     process_byte_impl(byte);
Chris@16: 
Chris@16:     // size_t max value = 0xFFFFFFFF
Chris@16:     //if (bit_count_low + 8 >= 0x100000000) { // would overflow
Chris@16:     //if (bit_count_low >= 0x100000000-8) {
Chris@16:     if (bit_count_low < 0xFFFFFFF8) {
Chris@16:         bit_count_low += 8;
Chris@16:     } else {
Chris@16:         bit_count_low = 0;
Chris@16: 
Chris@16:         if (bit_count_high <= 0xFFFFFFFE) {
Chris@16:             ++bit_count_high;
Chris@16:         } else {
Chris@16:             BOOST_THROW_EXCEPTION(std::runtime_error("sha1 too many bytes"));
Chris@16:         }
Chris@16:     }
Chris@16: }
Chris@16: 
Chris@16: inline void sha1::process_byte_impl(unsigned char byte)
Chris@16: {
Chris@16:     block_[block_byte_index_++] = byte;
Chris@16: 
Chris@16:     if (block_byte_index_ == 64) {
Chris@16:         block_byte_index_ = 0;
Chris@16:         process_block();
Chris@16:     }
Chris@16: }
Chris@16: 
Chris@16: inline void sha1::process_block(void const* bytes_begin, void const* bytes_end)
Chris@16: {
Chris@16:     unsigned char const* begin = static_cast<unsigned char const*>(bytes_begin);
Chris@16:     unsigned char const* end = static_cast<unsigned char const*>(bytes_end);
Chris@16:     for(; begin != end; ++begin) {
Chris@16:         process_byte(*begin);
Chris@16:     }
Chris@16: }
Chris@16: 
Chris@16: inline void sha1::process_bytes(void const* buffer, std::size_t byte_count)
Chris@16: {
Chris@16:     unsigned char const* b = static_cast<unsigned char const*>(buffer);
Chris@16:     process_block(b, b+byte_count);
Chris@16: }
Chris@16: 
Chris@16: inline void sha1::process_block()
Chris@16: {
Chris@16:     unsigned int w[80];
Chris@16:     for (std::size_t i=0; i<16; ++i) {
Chris@16:         w[i]  = (block_[i*4 + 0] << 24);
Chris@16:         w[i] |= (block_[i*4 + 1] << 16);
Chris@16:         w[i] |= (block_[i*4 + 2] << 8);
Chris@16:         w[i] |= (block_[i*4 + 3]);
Chris@16:     }
Chris@16:     for (std::size_t i=16; i<80; ++i) {
Chris@16:         w[i] = left_rotate((w[i-3] ^ w[i-8] ^ w[i-14] ^ w[i-16]), 1);
Chris@16:     }
Chris@16: 
Chris@16:     unsigned int a = h_[0];
Chris@16:     unsigned int b = h_[1];
Chris@16:     unsigned int c = h_[2];
Chris@16:     unsigned int d = h_[3];
Chris@16:     unsigned int e = h_[4];
Chris@16: 
Chris@16:     for (std::size_t i=0; i<80; ++i) {
Chris@16:         unsigned int f;
Chris@16:         unsigned int k;
Chris@16: 
Chris@16:         if (i<20) {
Chris@16:             f = (b & c) | (~b & d);
Chris@16:             k = 0x5A827999;
Chris@16:         } else if (i<40) {
Chris@16:             f = b ^ c ^ d;
Chris@16:             k = 0x6ED9EBA1;
Chris@16:         } else if (i<60) {
Chris@16:             f = (b & c) | (b & d) | (c & d);
Chris@16:             k = 0x8F1BBCDC;
Chris@16:         } else {
Chris@16:             f = b ^ c ^ d;
Chris@16:             k = 0xCA62C1D6;
Chris@16:         }
Chris@16: 
Chris@16:         unsigned temp = left_rotate(a, 5) + f + e + k + w[i];
Chris@16:         e = d;
Chris@16:         d = c;
Chris@16:         c = left_rotate(b, 30);
Chris@16:         b = a;
Chris@16:         a = temp;
Chris@16:     }
Chris@16: 
Chris@16:     h_[0] += a;
Chris@16:     h_[1] += b;
Chris@16:     h_[2] += c;
Chris@16:     h_[3] += d;
Chris@16:     h_[4] += e;
Chris@16: }
Chris@16: 
Chris@16: inline void sha1::get_digest(digest_type digest)
Chris@16: {
Chris@16:     // append the bit '1' to the message
Chris@16:     process_byte_impl(0x80);
Chris@16: 
Chris@16:     // append k bits '0', where k is the minimum number >= 0
Chris@16:     // such that the resulting message length is congruent to 56 (mod 64)
Chris@16:     // check if there is enough space for padding and bit_count
Chris@16:     if (block_byte_index_ > 56) {
Chris@16:         // finish this block
Chris@16:         while (block_byte_index_ != 0) {
Chris@16:             process_byte_impl(0);
Chris@16:         }
Chris@16: 
Chris@16:         // one more block
Chris@16:         while (block_byte_index_ < 56) {
Chris@16:             process_byte_impl(0);
Chris@16:         }
Chris@16:     } else {
Chris@16:         while (block_byte_index_ < 56) {
Chris@16:             process_byte_impl(0);
Chris@16:         }
Chris@16:     }
Chris@16: 
Chris@16:     // append length of message (before pre-processing) 
Chris@16:     // as a 64-bit big-endian integer
Chris@16:     process_byte_impl( static_cast<unsigned char>((bit_count_high>>24) & 0xFF) );
Chris@16:     process_byte_impl( static_cast<unsigned char>((bit_count_high>>16) & 0xFF) );
Chris@16:     process_byte_impl( static_cast<unsigned char>((bit_count_high>>8 ) & 0xFF) );
Chris@16:     process_byte_impl( static_cast<unsigned char>((bit_count_high)     & 0xFF) );
Chris@16:     process_byte_impl( static_cast<unsigned char>((bit_count_low>>24) & 0xFF) );
Chris@16:     process_byte_impl( static_cast<unsigned char>((bit_count_low>>16) & 0xFF) );
Chris@16:     process_byte_impl( static_cast<unsigned char>((bit_count_low>>8 ) & 0xFF) );
Chris@16:     process_byte_impl( static_cast<unsigned char>((bit_count_low)     & 0xFF) );
Chris@16: 
Chris@16:     // get final digest
Chris@16:     digest[0] = h_[0];
Chris@16:     digest[1] = h_[1];
Chris@16:     digest[2] = h_[2];
Chris@16:     digest[3] = h_[3];
Chris@16:     digest[4] = h_[4];
Chris@16: }
Chris@16: 
Chris@16: }}} // namespace boost::uuids::detail
Chris@16: 
Chris@16: #endif