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Avoid aliasing in chacha20_12::get_next_block

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This commit is contained in:
Peter Dimov
2024-04-23 05:23:35 +03:00
parent 378977a015
commit 79dceeeb49
1 changed files with 13 additions and 13 deletions
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26
include/boost/uuid/detail/chacha20.hpp
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@@ -36,32 +36,32 @@ private:
x[ c ] += x[ d ]; x[ b ] = rotl( x[b] ^ x[c], 7 );
}
void get_next_block( std::uint32_t (&result)[ 16 ] )
void get_next_block()
{
for( int i = 0; i < 16; ++i )
{
result[ i ] = state_[ i ];
block_[ i ] = state_[ i ];
}
for( int i = 0; i < 6; ++i )
{
quarter_round( result, 0, 4, 8, 12 );
quarter_round( result, 1, 5, 9, 13 );
quarter_round( result, 2, 6, 10, 14 );
quarter_round( result, 3, 7, 11, 15 );
quarter_round( result, 0, 5, 10, 15 );
quarter_round( result, 1, 6, 11, 12 );
quarter_round( result, 2, 7, 8, 13 );
quarter_round( result, 3, 4, 9, 14 );
quarter_round( block_, 0, 4, 8, 12 );
quarter_round( block_, 1, 5, 9, 13 );
quarter_round( block_, 2, 6, 10, 14 );
quarter_round( block_, 3, 7, 11, 15 );
quarter_round( block_, 0, 5, 10, 15 );
quarter_round( block_, 1, 6, 11, 12 );
quarter_round( block_, 2, 7, 8, 13 );
quarter_round( block_, 3, 4, 9, 14 );
}
for( int i = 0; i < 16; ++i )
{
result[ i ] += state_[ i ];
block_[ i ] += state_[ i ];
}
if( ++state_[ 12 ] == 0 ) ++state_[ 13 ];
}
}
public:
@@ -135,7 +135,7 @@ public:
{
if( index_ == 16 )
{
get_next_block( block_ );
get_next_block();
index_ = 0;
}