Java uses P12 certificate signing, verification, encryption, decryption

Required Jar:bouncycastle.jar

Configuration file Cert.properties

CERT_PATH=E://TEST.P12
cert_pwd=123456

The Certutil.java code is as follows

Package test.test;
Import Java.io.File;
Import Java.io.FileInputStream;
Import Java.io.InputStream;
Import Java.security.KeyStore;
Import Java.security.PrivateKey;
Import Java.security.PublicKey;
Import java.security.Security;
Import Java.security.Signature;
Import Java.security.cert.Certificate;
Import Java.security.cert.X509Certificate;
Import java.util.Enumeration;
Import Java.util.Iterator;
Import Java.util.LinkedHashMap;
Import Java.util.Map;

Import java.util.Properties;

Import Javax.crypto.Cipher;
Import Org.apache.log4j.Logger;

Import Org.bouncycastle.jce.provider.BouncyCastleProvider;
 /** * Class Name: CertUtil * Description: P12 certificate Tool type * Version: V1.0 * Modify April 3, 2017 morning 09:06:37 * copyright.
    * * Public class CertUtil {private static Logger Logger = Logger.getlogger (Certutil.class);

    private static KeyStore KeyStore;
    private static String Cert_path;
    private static String cert_pwd;
    Private final static String Key_store_type = "PKCS12"; static {Properties PRop = new Properties (); try {prop.load (Thread.CurrentThread (). Getcontextclassloader (). getResourceAsStream ("Test/test/cert.properties"
        ));
        catch (Exception e) {logger.error ("fail to read cert.properties ...");
        } Cert_path = Prop.getproperty ("Cert_path");

        Cert_pwd = Prop.getproperty ("Cert_pwd");
            if (KeyStore = = null) {try {KeyStore = Initkeystore ();
            catch (Exception e) {logger.error ("fail to init keystore ..."); }}/** * method: Getprivatekey * Description: Get private key * @return/public static Privatekey ge 
    Tprivatekey () throws Exception {return (Privatekey) Keystore.getkey (Getalias (), CertUtil.CERT_PWD.toCharArray ()); /** * Method: Getpublickey * Description: Get the Public key * @return * * * publickey Getpublickey ()
    Throws Exception {return getcertificate (). Getpublickey ();

  }  /** * Method: Getalias * Description: Get the first alias * @return/public static String Getalias () throws Exception {
        enumeration<string> aliases = keystore.aliases ();
        if (aliases.hasmoreelements ()) {return aliases.nextelement ();
    return null; /** * Method: Initkeystore * Description: Get KeyStore * @return * * * public static KeyStore Initkeystore () throw
        S Exception {security.addprovider (New Bouncycastleprovider ());
        KeyStore ks = keystore.getinstance (Certutil.key_store_type);
        Absolute path InputStream is = new FileInputStream (new File (Certutil.cert_path));
        Relative path//inputstream is = Thread.CurrentThread (). Getcontextclassloader (). getResourceAsStream (Certutil.cert_path);
        Ks.load (IS, CertUtil.CERT_PWD.toCharArray ());
        Is.close ();
    return KS; /** * Method: GetCertificate * Description: Obtain certificate * @return/public static certificate GetcertifiCate () throws Exception {return keystore.getcertificate (Getalias ());
     /** * Method: Getcipher * Description: Get cipher * @param ispublic whether public key mode * @param mode encryption/decryption * @return
        */public static Cipher Getcipher (boolean ispublic, int mode) throws Exception {Cipher Cipher = null;
            if (ispublic) {PublicKey PublicKey = Getpublickey ();  
            cipher = Cipher.getinstance (Publickey.getalgorithm ());
        Cipher.init (mode, publickey); 
            }else{Privatekey Privatekey = Getprivatekey ();  
            cipher = Cipher.getinstance (Privatekey.getalgorithm ());  
        Cipher.init (mode, privatekey);
    return cipher; /** * Method: Bytestostrhex * Description: Array converted to 16 String * @param bytes Source array * @return string/Publ
        IC Static final String bytestostrhex (byte[] bytes) {stringbuffer sb = new StringBuffer (bytes.length);
        String stemp; for (inti = 0; i < bytes.length;
            i++) {stemp = integer.tohexstring (0xFF & Bytes[i]);
            if (Stemp.length () < 2) sb.append (0);
        Sb.append (Stemp.touppercase ());
    return sb.tostring ();
    /** * Method: Hexstrtobytes * Description: Restore 16 to byte array * @param str 16 String * @return byte[] * *
        private static final byte[] Hexstrtobytes (String str) {byte[] bytes;
        bytes = new Byte[str.length ()/2]; for (int i = 0; i < bytes.length i++) {bytes[i] = (byte) integer.parseint (str.substring (2 * I, 2 * i + 2)
        , 16);
    return bytes; }/*========================================== Signature ================================================*//** * method : Sign * Description: Digitally sign and convert into * @param requestmap source data * @return/public static String sign (Map<strin G, string> Requestmap) throws Exception {//concatenation of request Parameters success string: Value1value2valuE3 ...
        StringBuffer sourcedata = new StringBuffer (); For (iterator<map.entry<string, string>> iter = Requestmap.entryset (). iterator (); Iter.hasnext ();)
            {map.entry<string, string> Entry = Iter.next ();
        Sourcedata.append (Entry.getvalue ());
        } byte[] bytes = sign (sourcedata.tostring (). GetBytes ());
    Return Bytestostrhex (bytes); /** * Method: Sign * Description: Digital signature * @param bytedata Source byte * @return/public static byte[] Sign
        (byte[] bytedata) throws Exception {Privatekey Privatekey = Getprivatekey ();
        X509Certificate x509certificate= (X509Certificate) getcertificate ();
        Signature Signature = signature.getinstance (X509certificate.getsigalgname ());
        Signature.initsign (Privatekey);
        Signature.update (Bytedata);
    return Signature.sign ();
  /** * Method: Verify * Description: In-process conversion and verification * @param SIGNSTR Signature String * @param requestmap source data   * @return */public static Boolean verify (String signstr, map<string, string> requestmap) throws Excepti

        On {byte[] SignData = hexstrtobytes (SIGNSTR);
        StringBuffer sourcedata = new StringBuffer (); For (iterator<map.entry<string, string>> iter = Requestmap.entryset (). iterator (); Iter.hasnext ();)
            {map.entry<string, string> Entry = Iter.next ();
        Sourcedata.append (Entry.getvalue ());
    Return Verify (Sourcedata.tostring (). GetBytes (), signdata); 
     /** * Method: Verify * Description: Certificate contains public key checksum signature * @param sourcedata source byte * @param signdata signature byte * @return */public static Boolean verify (Byte[] sourcedata,byte[] signdata) throws Exception {X509Certificate x5
        09Certificate = (x509certificate) getcertificate ();
        Signature Signature = signature.getinstance (X509certificate.getsigalgname ());
        Signature.initverify (X509Certificate); Signature.updaTe (SourceData);
    Return signature.verify (SignData); 
     /*========================================== Encryption =======================================*//** * Method: Encrypt * Description: Encrypt and convert into * @param requestmap source data * @param ispubencrypt whether to use public key encryption * @return * Tic string Encrypt (map<string, string> Requestmap, Boolean ispubencrypt) throws Exception {//concatenation of request parameters Success String: V
        Alue1value2value3 ...
        StringBuffer sourcedata = new StringBuffer (); For (iterator<map.entry<string, string>> iter = Requestmap.entryset (). iterator (); Iter.hasnext ();)
            {map.entry<string, string> Entry = Iter.next ();
        Sourcedata.append (Entry.getvalue ());
        } byte[] EncryptData = Encrypt (Sourcedata.tostring (). GetBytes (), ispubencrypt);
    Return Bytestostrhex (encryptdata); /** * Method: Encrypt * Description: Encryption * @param encryptdata to encrypt bytes * @param ispubencrypt whether to use public key encryption * @return */public static byte[] Encrypt (byte[] encryptdata, Boolean ispubencrypt) throws Exception {Cip
        Her cipher = Getcipher (Ispubencrypt, Cipher.encrypt_mode);
    Return cipher.dofinal (encryptdata);  /** * Method: Decrypt * Description: Convert into and decrypt * @param decryptstr encrypted String * @param ispubdecrypt whether to use public key decryption * @return */public static string decrypt (String decryptstr, Boolean ispubdecrypt) throws Exception {byte
        [] Decryptdata = Hexstrtobytes (DECRYPTSTR);
    return new String (Decrypt (Decryptdata, ispubdecrypt)); /** * Method: Decrypt * Description: Decrypt * @param decryptdata encrypted byte * @param ispubdecrypt whether to use public key decryption * @ret
        URN */public static byte[] Decrypt (byte[] Decryptdata, Boolean ispubdecrypt) throws Exception {
        Cipher Cipher = Getcipher (Ispubdecrypt, Cipher.decrypt_mode);

    Return cipher.dofinal (Decryptdata); public static void Main (string[] args) throws Exception {map<string, string> requestmap = new linkedhashmap<> ();
        Requestmap.put ("Batchno", "17005846899643554");
        Requestmap.put ("Amount", "100005");
        Requestmap.put ("Uapcode", "152516");

        SYSTEM.OUT.PRINTLN ("Request data:" + requestmap.tostring ());
        String signstr = certutil.sign (Requestmap);
        SYSTEM.OUT.PRINTLN ("Signature data:" + signstr);

        System.out.println ("Verification Result:" + certutil.verify (SIGNSTR, Requestmap));
        String priencryptstr = Certutil.encrypt (Requestmap, false);
        SYSTEM.OUT.PRINTLN ("Private key Encryption" + PRIENCRYPTSTR);

        SYSTEM.OUT.PRINTLN ("Public key decryption" + Certutil.decrypt (Priencryptstr, true));
        String pubencryptstr = Certutil.encrypt (Requestmap, true);
        SYSTEM.OUT.PRINTLN ("Public key Encryption" + PUBENCRYPTSTR);


    SYSTEM.OUT.PRINTLN ("Private key Decryption" + Certutil.decrypt (Pubencryptstr, false));
 }
}

The

results are as follows