关于RSA公私钥的生成，获取

本文主要是针对网上的常见RSA加密不能指定密钥的坑....RSA可通过这种方式生成密钥:/*** 随机生成公钥和私钥
*/public static final String publicKeyString = "publicKeyString";
public static final String privateKeyString = "privateKeyString";public static HashMap<String, String> getRandomKey() throws NoSuchAlgorithmException, InvalidKeySpecException{KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance("RSA");keyPairGen.initialize(1024);//生成大小 1024KeyPair keyPair = keyPairGen.generateKeyPair();RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();//获取公钥RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();//获取私钥HashMap<String, String> keyMap = new HashMap<String, String>();keyMap.put(publicKeyString, Base64.encodeToString(publicKey.getEncoded(), Base64.DEFAULT));//获取公钥Base64编码keyMap.put(privateKeyString, Base64.encodeToString(privateKey.getEncoded(), Base64.DEFAULT));//获取密钥Base64编码return keyMap;
}公钥：
MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCa3+L0QRaExWO6m28pkLvp/c+XRQ/7ZM8DSJ+HAysytAimnn0ouDUFCy1jcLCQLgcaR9WVqBsPHigZJYwMo6/nd5upwP63BfvZoPnhgK216atkStUKDtmMS2TLnJptjtZcb0g8K+zsbTvYPpv3g+1N7rWgCD4zEtVm/LMyZ7NURwIDAQAB私钥：
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重点来了,获取私钥公钥很简单,重要的是怎么把这点字符串再设置进去~/**
* 通过字符串生成私钥
*/
public static PrivateKey getPrivateKey(String privateKeyData){PrivateKey privateKey = null;try {byte[] decodeKey = Base64.decode(privateKeyData,Base64.DEFAULT); //将字符串Base64解码PKCS8EncodedKeySpec x509= new PKCS8EncodedKeySpec(decodeKey);//创建x509证书封装类KeyFactory keyFactory = KeyFactory.getInstance("RSA");//指定RSAprivateKey = keyFactory.generatePrivate(x509);//生成私钥} catch (NoSuchAlgorithmException e) {e.printStackTrace();} catch (InvalidKeySpecException e) {e.printStackTrace();}return privateKey;
}/**
* 通过字符串生成公钥
*/
public static PublicKey getPublicKey(String publicKeyData){PublicKey publicKey = null;try {byte[] decodeKey = Base64.decode(publicKeyData, Base64.DEFAULT);X509EncodedKeySpec x509 = new X509EncodedKeySpec(decodeKey);KeyFactory keyFactory = KeyFactory.getInstance("RSA");publicKey = keyFactory.generatePublic(x509);} catch (NoSuchAlgorithmException e) {e.printStackTrace();} catch (InvalidKeySpecException e) {e.printStackTrace();}return publicKey;
}搞定,拿到了私钥公钥...你懂得 ,开始加密解密.../**
* 加密
*/
public static byte[] encrypt(String data,Key key){try {//取公钥KeyFactory keyFactory = KeyFactory.getInstance("RSA");Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());cipher.init(Cipher.ENCRYPT_MODE, key);return cipher.doFinal(data.getBytes());} catch (Exception e) { e.printStackTrace(); }return null;}/**
* 解密
*/
public static byte[] decrypt(byte[] data,Key key){try {Cipher cipher = Cipher.getInstance("RSA");cipher.init(Cipher.DECRYPT_MODE, key);return cipher.doFinal(data);} catch (Exception e) { e.printStackTrace(); } return null;
}