Java實作國密Z值填充

private String zPadding(String pubkeyHex,String inDataHex){
		String smX="";
		String smY="";
		String userID="";
		String hexdata = inDataHex;
		String publicKeyHex = pubkeyHex;
		if(publicKeyHex!=null&& !"".equals(publicKeyHex)){
			smX=publicKeyHex.substring(0,64);
			smY=publicKeyHex.substring(64,publicKeyHex.length());
		}
		userID="31323334353637383132333435363738";
		byte[]zpading=SM2.Instance().sm2GetZSM( FileManager.hexToBytes(userID),smX, smY);
		hexdata=FileManager.bytesToHex(zpading)+hexdata;
		
		return hexdata;
	}
           

初始向量設定是31323334353637383132333435363738  對應是12345678， 公鑰截取頭32位元組作為公鑰X，截取後32位元組作為公鑰Y ，使用公鑰X和Y做SM3運算

public byte[] sm2GetZSM(byte[] userId,String smX,String smY)
	{
		SM3Digest sm3 = new SM3Digest();
		
		int len = userId.length * 8;
		sm3.update((byte) (len >> 8 & 0xFF));
		sm3.update((byte) (len & 0xFF));
		sm3.update(userId, 0, userId.length);
		
		byte[] p = Util.byteConvert32Bytes(ecc_a);
		sm3.update(p, 0, p.length);
		
		p = Util.byteConvert32Bytes(ecc_b);
		sm3.update(p, 0, p.length);
		
		p = Util.byteConvert32Bytes(ecc_gx);
		sm3.update(p, 0, p.length);
		
		p = Util.byteConvert32Bytes(ecc_gy);
		sm3.update(p, 0, p.length);
		
		//p = Util.byteConvert32Bytes(userKey.getX().toBigInteger());
		p = Util.hexStringToBytes(smX);
		sm3.update(p, 0, p.length);
		
	//	p = Util.byteConvert32Bytes(userKey.getY().toBigInteger());
		p =  Util.hexStringToBytes(smY);
		sm3.update(p, 0, p.length);
		
		byte[] md = new byte[sm3.getDigestSize()];
		sm3.doFinal(md, 0);
		return md;
	}
           

可以下載下傳附件擷取

https://download.csdn.net/download/qgy92320/11878279