code: public static byte[] changeC1C2C3ToC1C3C2(byte[] c1c2c3, ECDomainParameters ecDomainParameters) {
  		// sm2p256v1的这个固定65。可看GMNamedCurves、ECCurve代码。
  		final int c1Len = (ecDomainParameters.getCurve().getFieldSize() + 7) / 8 * 2 + 1;
  		final int c3Len = 32; // new SM3Digest().getDigestSize();
  		byte[] result = new byte[c1c2c3.length];
  		System.arraycopy(c1c2c3, 0, result, 0, c1Len); // c1
  		System.arraycopy(c1c2c3, c1c2c3.length - c3Len, result, c1Len, c3Len); // c3
  		System.arraycopy(c1c2c3, c1Len, result, c1Len + c3Len, c1c2c3.length - c1Len - c3Len); // c2
  		return result;
  	}
docs: bc加解密使用旧标c1||c2||c3，此方法在加密后调用，将结果转化为c1||c3||c2
  
  @param c1c2c3 加密后的bytes，顺序为C1C2C3
  @param ecDomainParameters {@link ECDomainParameters}
  @return 加密后的bytes，顺序为C1C3C2