RSA XML格式秘钥转Pem并解密

梦里梦外; 2021-11-16 08:42 311阅读 0赞

### 一.XML格式秘钥转Pem格式 ###

package VerifyLicense;
    
    import java.io.*;
    import java.math.BigInteger;
    import java.security.*;
    import java.security.spec.*;
    import javax.xml.parsers.DocumentBuilder;
    import javax.xml.parsers.DocumentBuilderFactory;
    import org.w3c.dom.*;
    
    public class RSAXmlToPem {
    
        private static final int PRIVATE_KEY = 1;
        private static final int PUBLIC_KEY = 2;
        private static final String[] PRIVATE_KEY_XML_NODES =  { "Modulus", "Exponent", "P", "Q", "DP", "DQ", "InverseQ", "D" };
        private static final String[] PUBLIC_KEY_XML_NODES =  { "Modulus", "Exponent" };
        
        
        /**
         * xml格式秘钥转为Pem格式秘钥
         * @param xmlStr  xml格式私钥字符串
         * @return pem格式秘钥
         */
        public static String transXmlStrToPem (String xmlStr){
            String pem = "";
            try {
                Document XMLSecKeyDoc = parseXMLStr(xmlStr);
                int keyType = getKeyType(XMLSecKeyDoc);
                if (keyType == PRIVATE_KEY) {
                    pem = convertXMLRSAPrivateKeyToPEM(XMLSecKeyDoc);
                } else {
                    pem = convertXMLRSAPublicKeyToPEM(XMLSecKeyDoc);
                }
            }
            catch (Exception e) {
                e.printStackTrace();
            }
            System.out.println(pem);
            return pem;
        }
    
        /**
         * xml格式秘钥转为Pem格式秘钥
         * @param path  xml格式私钥文件地址
         * @return pem格式秘钥
         */
        public static String transXmlTotPem(String path){
            String pem = "";
            try {
                Document XMLSecKeyDoc = parseXMLFile(path);
                int keyType = getKeyType(XMLSecKeyDoc);
    
                if (keyType == PRIVATE_KEY) {
                    pem = convertXMLRSAPrivateKeyToPEM(XMLSecKeyDoc);
                } else {
                    pem = convertXMLRSAPublicKeyToPEM(XMLSecKeyDoc);
                }
            }
            catch (Exception e) {
                e.printStackTrace();
            }
            return pem;
        }
    
        /**
         * 获得秘钥类型
         * @param xmldoc
         * @return
         */
        private static int getKeyType(Document xmldoc) {
    
            Node root = xmldoc.getFirstChild();
            if (!root.getNodeName().equals("RSAKeyValue")) {
                System.out.println("Expecting <RSAKeyValue> node, encountered <" + root.getNodeName() + ">");
                return 0;
            }
            NodeList children = root.getChildNodes();
            if (children.getLength() == PUBLIC_KEY_XML_NODES.length) {
                return PUBLIC_KEY;
            }
            return PRIVATE_KEY;
    
        }
    
        /**
         * 检查秘钥是否符合格式
         * @param keyType
         * @param xmldoc
         * @return
         */
        private static boolean checkXMLRSAKey(int keyType, Document xmldoc) {
    
            Node root = xmldoc.getFirstChild();
            NodeList children = root.getChildNodes();
            String[] wantedNodes = {};
            if (keyType == PRIVATE_KEY) {
                wantedNodes = PRIVATE_KEY_XML_NODES;
            } else {
                wantedNodes = PUBLIC_KEY_XML_NODES;
            }
            for (int j = 0; j < wantedNodes.length; j++) {
                String wantedNode = wantedNodes[j];
                boolean found = false;
                for (int i = 0; i < children.getLength(); i++) {
                    if (children.item(i).getNodeName().equals(wantedNode)) {
                        found = true;
                        break;
                    }
                }
                if (!found) {
                    System.out.println("Cannot find node <" + wantedNode + ">");
                    return false;
                }
            }
            return true;
    
        }
    
        /**
         *  将xml格式私钥转为PEM格式
         * @param xmldoc
         * @return
         */
        private static String convertXMLRSAPrivateKeyToPEM(Document xmldoc) {
    
            Node root = xmldoc.getFirstChild();
            NodeList children = root.getChildNodes();
    
            BigInteger modulus = null, exponent = null, primeP = null, primeQ = null,
                    primeExponentP = null, primeExponentQ = null,
                    crtCoefficient = null, privateExponent = null;
    
            for (int i = 0; i < children.getLength(); i++) {
    
                Node node = children.item(i);
                String textValue = node.getTextContent();
                if (node.getNodeName().equals("Modulus")) {
                    modulus = new BigInteger(b64decode(textValue));
                } else if (node.getNodeName().equals("Exponent")) {
                    exponent = new BigInteger(b64decode(textValue));
                } else if (node.getNodeName().equals("P")) {
                    primeP = new BigInteger(b64decode(textValue));
                } else if (node.getNodeName().equals("Q")) {
                    primeQ = new BigInteger(b64decode(textValue));
                } else if (node.getNodeName().equals("DP")) {
                    primeExponentP = new BigInteger(b64decode(textValue));
                } else if (node.getNodeName().equals("DQ")) {
                    primeExponentQ = new BigInteger(b64decode(textValue));
                } else if (node.getNodeName().equals("InverseQ")) {
                    crtCoefficient = new BigInteger(b64decode(textValue));
                } else if (node.getNodeName().equals("D")) {
                    privateExponent = new BigInteger(b64decode(textValue));
                }
    
            }
    
            try {
                RSAPrivateCrtKeySpec keySpec = new RSAPrivateCrtKeySpec (
                        modulus, exponent, privateExponent, primeP, primeQ,
                        primeExponentP, primeExponentQ, crtCoefficient);
    
                KeyFactory keyFactory = KeyFactory.getInstance("RSA");
                PrivateKey key = keyFactory.generatePrivate(keySpec);
                return b64encode(key.getEncoded());
    
            } catch (Exception e) {
                e.printStackTrace();
            }
            return null;
    
        }
    
        /**
         *  将xml格式公钥转为PEM格式
         * @param xmldoc
         * @return
         */
        private static String convertXMLRSAPublicKeyToPEM(Document xmldoc) {
    
            Node root = xmldoc.getFirstChild();
            NodeList children = root.getChildNodes();
    
            BigInteger modulus = null, exponent = null;
    
            for (int i = 0; i < children.getLength(); i++) {
    
                Node node = children.item(i);
                String textValue = node.getTextContent();
                if (node.getNodeName().equals("Modulus")) {
                    modulus = new BigInteger(b64decode(textValue));
                } else if (node.getNodeName().equals("Exponent")) {
                    exponent = new BigInteger(b64decode(textValue));
                }
    
            }
    
            try {
    
                RSAPublicKeySpec keySpec = new RSAPublicKeySpec(modulus, exponent);
    
                KeyFactory keyFactory = KeyFactory.getInstance("RSA");
                PublicKey key = keyFactory.generatePublic(keySpec);
                return b64encode(key.getEncoded());
    
            } catch (Exception e) {
                e.printStackTrace();
            }
            return null;
    
        }
    
        /**
         * 将xml格式字符串格式化城Document格式
         * @param xmlStr
         * @return
         */
        private static Document parseXMLStr(String xmlStr) {
            try {
                InputStream  in=new ByteArrayInputStream(xmlStr.getBytes());
                DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
                DocumentBuilder builder = factory.newDocumentBuilder();
                Document document = builder.parse(in);
                return document;
            } catch(Exception e) {
                e.printStackTrace();
                return null;
            }
        }
    
        /**
         * 将某个包含xml的文件转换为Document格式
         * @param filename
         * @return
         */
        private static Document parseXMLFile(String filename) {
            try {
                DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
                DocumentBuilder builder = factory.newDocumentBuilder();
                Document document = builder.parse( new File(filename) );
                return document;
            } catch(Exception e) {
                e.printStackTrace();
                return null;
            }
        }
    
        private static final String b64encode(byte[] data) {
            sun.misc.BASE64Encoder enc = new sun.misc.BASE64Encoder() ;
            String b64str = enc.encodeBuffer(data).trim();
            return b64str;
        }
    
        private static final byte[] b64decode(String data) {
            try {
                sun.misc.BASE64Decoder dec = new sun.misc.BASE64Decoder() ;
                byte[] bytes = dec.decodeBuffer(data.trim());
                return bytes;
            } catch (IOException e) {
                e.printStackTrace();
            }
            return null;
        }
        
    }

### 二.RSA私钥解密，支持Pem格式秘钥，xml格式不支持 ###

**pom中加入依赖：**

<dependency>
                <groupId>commons-codec</groupId>
                <artifactId>commons-codec</artifactId>
                <version>1.12</version>
            </dependency>

package VerifyLicense;
    
    import java.io.*;
    import java.security.*;
    import java.security.interfaces.RSAPrivateKey;
    import java.security.spec.*;
    import javax.crypto.Cipher;
    import org.apache.commons.codec.binary.Base64;
    
    
    public class RSAUtil {
        
        /**
         * RSA私钥解密
         * @param strPath 加密字符串文件路径
         * @param privateKeyPath xml私钥文件路径
         * @return 铭文
         */
        public static String decryptXmlRSA(String strPath, String privateKeyPath){
            String str = readFile(strPath);
            String privateKey = RSAXmlToPem.transXmlTotPem(privateKeyPath);
            String code = "";
            try {
                code = decrypt(str,privateKey);
            } catch (Exception e) {
                e.printStackTrace();
            }
            return code;
        }
    
        /**
         * RSA私钥解密
         * @param str 加密字符串
         * @param xmlPrivateKey xml格式私钥字符串
         * @return 铭文
         */
        public static String decryptXmlStrRSA(String str, String xmlPrivateKey){
            String code = "";
            String privateKey = RSAXmlToPem.transXmlStrToPem(xmlPrivateKey);
            try {
                code = decrypt(str,privateKey);
            } catch (Exception e) {
                e.printStackTrace();
            }
            return code;
        }
    
    
        /**
         * RSA私钥解密，支持Pem格式秘钥，xml格式不支持
         * @param str 加密字符串
         * @param privateKey 私钥
         * @return 铭文
         * @throws Exception 解密过程中的异常信息
         */
        public static String decrypt(String str, String privateKey) throws Exception{
            //64位解码加密后的字符串
            byte[] inputByte = Base64.decodeBase64(str.getBytes("UTF-8"));
            //base64编码的私钥
            byte[] decoded = Base64.decodeBase64(privateKey);
            RSAPrivateKey priKey = (RSAPrivateKey) KeyFactory.getInstance("RSA").generatePrivate(new PKCS8EncodedKeySpec(decoded));
            //RSA解密
            Cipher cipher = Cipher.getInstance("RSA");
            cipher.init(Cipher.DECRYPT_MODE, priKey);
            String outStr = new String(cipher.doFinal(inputByte));
            return outStr;
        }
    
        /**
         * 读取文件内容
         * @param filepath
         * @return
         */
        public static String readFile(String filepath) {
            FileReader re = null;
            BufferedReader buff = null;
            String line = "";
            try {
                File file = new File(filepath);
                re = new FileReader(file);
                buff = new BufferedReader(re);
                String tempString = null;
                while ((tempString = buff.readLine()) != null) {
                    line += tempString;
                }
                return line;
            } catch (Exception e) {
                e.printStackTrace();
            } finally {
                try {
                    re.close();
                    buff.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return line;
        }
    
    
        /**
         * 寻找证书文件
         * 证书文件一般会放在某个特定的文件夹，并以特定格式结尾，在不知道该验证证书文件完整名称的时候
         * 我们寻找以某文件结尾的文件，前提是，该文件夹下只有一个该格式文件，否则应该以全名检索
         * @param path
         * @param endStr
         * @return
         */
        public static String getEncryptionFile(String path,String endStr) {
            File file = new File(path);
            File[] array = file.listFiles();
    
            for (int i = 0; i < array.length; i++) {
                if (array[i].isFile()) {
                    if (array[i].getPath().endsWith(endStr)){
                        return array[i].getPath();
                    }
                } else if (array[i].isDirectory()) {
                    continue;
                }
            }
            return "";
        }
    
    }