Java簽名、驗籤、解密與解析證書

載入BC（可選）：

    ...
    Security.addProvider(new BouncyCastleProvider());
    ...

簽名：

public byte[] signData_SHA256withRSA(byte[] data, String p12file, String passwd) throws Exception {
	FileInputStream fis = new FileInputStream(p12file);
	KeyStore ks = KeyStore.getInstance("JKS");
	ks.load(fis, passwd.toCharArray());
	fis.close();
	String alias = "";
	Enumeration<String> aliases = ks.aliases();
	while (aliases.hasMoreElements()) {
		alias = aliases.nextElement();
		break;
	}

	PrivateKey priKey = (PrivateKey) ks.getKey(alias, passwd.toCharArray());
	Signature signature = Signature.getInstance("SHA256withRSA");
	signature.initSign(priKey);
	signature.update(data);
	byte[] signedData = signature.sign();

	return signedData;
}

驗籤：

RSA

public Boolean verifySign_SHA256withRSA(byte[] bData, byte[] bSign, byte[] bCert) throws Exception {
	boolean result = false;

	CertificateFactory cf = CertificateFactory.getInstance("X.509", "BC");
	ByteArrayInputStream iData = new ByteArrayInputStream(bCert);
	Certificate oCert = cf.generateCertificate(iData);
	Provider oProvider = Security.getProvider("BC");
	Signature oSig = Signature.getInstance("SHA256withRSA", oProvider);
	oSig.initVerify(oCert.getPublicKey());
	oSig.update(bData);
	result = oSig.verify(bSign);

	return result;
}

SM2

public boolean verifySign_SM3withSM2(byte[] bData, byte[] bSign, byte[] bCert) throws Exception {
	boolean result = false;

	CertificateFactory cf = CertificateFactory.getInstance("X.509", "BC");
	ByteArrayInputStream iData = new ByteArrayInputStream(bCert);
	Certificate oCert = cf.generateCertificate(iData);
	Provider oProvider = Security.getProvider("BC");
	Signature oSig = Signature.getInstance("SM3withSM2", oProvider);
	oSig.initVerify(oCert.getPublicKey());
	oSig.update(bData);
	result = oSig.verify(bSign);

	return result;
}

 

解密：

public byte[] encrypt(String certPath, byte data[]) throws Exception {
	FileInputStream oFile = new FileInputStream(certPath);
	CertificateFactory cf = CertificateFactory.getInstance("X.509");
	java.security.cert.Certificate cert = cf.generateCertificate(oFile);
	PublicKey pk = null;
	
	try {
		pk = cert.getPublicKey();
	} catch (Exception e) {
		e.printStackTrace();
		return null;
	}
	
	Cipher cipher = null;
	byte bRet[] = (byte[]) null;
	try {
		cipher = Cipher.getInstance("RSA");
	} catch (Exception e) {
		e.printStackTrace();
		return null;
	}

	try {
		cipher.init(1, pk);
	} catch (Exception e) {
		e.printStackTrace();
		return null;
	}

	try {
		bRet = cipher.doFinal(data);
	} catch (Exception e) {
		e.printStackTrace();
		return null;
	}

	return bRet;
}

解析證書：

public CertInfo getCertInfo(String cert) throws Exception {
	CertInfo result = null;

	byte[] bcert = Base64.decode(cert);
	ASN1InputStream asn1Input = new ASN1InputStream(new ByteArrayInputStream(bcert));
	ASN1Primitive asn1X509 = asn1Input.readObject();
	org.bouncycastle.asn1.x509.Certificate x509 = org.bouncycastle.asn1.x509.Certificate.getInstance(asn1X509);
	asn1Input.close();

	String certSn = x509.getSerialNumber().getValue().toString(16);
	Date notBefore = x509.getStartDate().getDate();
	Date notAfter = x509.getEndDate().getDate();
	RDN dn = x509.getSubject().getRDNs(BCStyle.CN)[0];
	String commonName = dn.getFirst().getValue().toString();

	String something = "";
	ASN1InputStream asnInputStream = null;
	ByteArrayInputStream inStream = null;
	try {
		ASN1ObjectIdentifier oid = new ASN1ObjectIdentifier("<oid of something>");
		org.bouncycastle.asn1.x509.Extension ext = x509.getTBSCertificate().getExtensions().getExtension(oid);
		DEROctetString oct = (DEROctetString) ext.getExtnValue();
		inStream = new ByteArrayInputStream(oct.getOctets());
		asnInputStream = new ASN1InputStream(inStream);
		DERTaggedObject derObject = (DERTaggedObject) asnInputStream.readObject();
		DERPrintableString s = (DERPrintableString) derObject.getObject();
		something = s.getString();
	} catch (Exception ex) {
		log.warn("get something error", ex);
	} finally {
		if (inStream != null) {
			inStream.close();
		}

		if (asnInputStream != null) {
			asnInputStream.close();
		}
	}

	result = new CertInfo();
	result.certsn = certSn;
	result.cn = commonName;
	result.notbefore = notBefore;
	result.notafter = notAfter;
	result.something = something;

	return result;
}

望指正