C#

internal static string ByteArrayToHexString( byte[] buf )
{
	StringBuilder sb = new StringBuilder( buf.Length );
	for ( int i = 0; i != buf.Length; ++i )
	{
		sb.Append( buf[i].ToString( "X2" ) );
	}
	return ( sb.ToString() );
}

internal unsafe static string ByteArrayToHexString( byte[] buf, int iLen )
{
	char[] chs1 = s_acharval;
	if ( chs1 == null )
	{
		chs1 = new char[16];
		int i = (int)chs1.Length;
		while ( --i >= 0 )
		{
			if ( i < 10 )
			{
				chs1[i] = (char)( 48 + i );
			}
			else
			{
				chs1[i] = (char)( 65 + ( i - 10 ) );
			}
		}
		s_acharval = chs1;
	}
	if ( buf == null )
	{
		return null;
	}
	if ( iLen == 0 )
	{
		iLen = (int)buf.Length;
	}
	char[] chs2 = new char[(uint)(iLen * 2)];
	fixed ( char* ch1 = &chs2[0])
	{
		fixed ( char* ch2 = &chs1[0])
		{
			fixed ( byte* b1 = &buf[0] )
			{
				char* ch3 = ch1;
				byte* b2 = b1;
				while ( --iLen >= 0 )
				{
					*ch3++ = *( ch2 + ( 2 * (( *b2 & 240 ) >> 4  )));
					*ch3++ = *( ch2 + ( 2 * ( *b2 & 15 )));
					b2++;
				}
			}
		}
	}

	return new String( chs2 );
}