for(int i = length - 1; i >= 0; i--) {
dst[i * 2 + 1] = hexadecimals[(unsigned char) src[i] & 15];
dst[i * 2] = hexadecimals[(unsigned char) src[i] >> 4];
for(int i = length - 1; i >= 0; i--) {
dst[i * 2 + 1] = hexadecimals[(unsigned char) src[i] & 15];
dst[i * 2] = hexadecimals[(unsigned char) src[i] >> 4];