java生成rsa加密
1、用公鑰加密，用私鑰解密。
2、給別人發信息，就從伺服器上拉下來別人的公鑰，加密後發給他。
3、對方拿到信息後用自己的私鑰解密。
4、這樣，公鑰加密後除了私鑰持有人，別人都看不到信息。
5、若是用私鑰加密，那麼公鑰都能解密，還有何安全性可言？
6、私鑰加密的場合只有一個，那就是數字簽名，用來表明這個信息來源於你。
㈡ JAVA寫RSA加密，公鑰私鑰都是一樣的，為什麼每次加密的結果不一樣
因為rsa是非對稱加密，它使用的是隨機大素數的抽取，每次隨機生成的，所以每次加密的結果不可能一樣
㈢ java生成rsa密鑰，c++可以直接使用密鑰解密嗎
可以的，RSA加密解密有一套規則的，不同的語言都會遵循，只是實現的方式不一樣。
用對應的的公鑰就可以進行解密
㈣ java生成的rsa公鑰 能在python上使用嗎
肯定可以，這個跟語言是無關的
Python上RSA加密的庫挺多的，最開始使用的是rsa，因為比較簡單嘛！測試的時候也是用 python模擬App的訪問，順利通過！
然而App開發者反饋，python測試腳本沒法移植到java上，因為java的加密解密模塊需要更加精細的演算法細節指定，否則java加密過的數據python是解不出來的。
當初就是因為rsa模塊簡單，不需要注重細節才選的，自己又不是專業搞加密解密的。沒辦法了，只能硬著頭皮，捋了一遍RSA的加密原理。網上還是有比較多的講述比較好的文章，比如RSA演算法原理
原理是懂了，但具體到python和java的區別上，還是一頭霧水。最終python的RSA模塊換成Crypto，因為支持的參數比較多。搜了很多網站講的都不是很詳細，stackflow上有幾篇還可以，借鑒了一下，最後測試通過了。還是直接上代碼吧。
Java代碼
//下面這行指定了RSA演算法的細節，必須更python對應
private static String RSA_CONFIGURATION = "RSA/ECB/OAEPWithSHA-256AndMGF1Padding";
//這個貌似需要安裝指定的provider模塊，這里沒有使用
private static String RSA_PROVIDER = "BC";
//解密 Key：私鑰
public static String decrypt(Key key, String encryptedString){
try {
Cipher c = Cipher.getInstance(RSA_CONFIGURATION);
c.init(Cipher.DECRYPT_MODE, key, new OAEPParameterSpec("SHA-256", "MGF1", MGF1ParameterSpec.SHA256,
PSource.PSpecified.DEFAULT));
byte[] decodedBytes;
decodedBytes = c.doFinal(Base64.decode(encryptedString.getBytes("UTF-8")));
return new String(decodedBytes, "UTF-8");
} catch (IllegalBlockSizeException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (BadPaddingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (Base64DecodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (NoSuchAlgorithmException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (NoSuchPaddingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InvalidKeyException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch ( e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
//加密 Key一般是公鑰
public static String encrypt(Key key, String toBeEncryptedString){
try {
Cipher c = Cipher.getInstance(RSA_CONFIGURATION);
c.init(Cipher.ENCRYPT_MODE, key, new OAEPParameterSpec("SHA-256", "MGF1", MGF1ParameterSpec.SHA256,
PSource.PSpecified.DEFAULT));
byte[] encodedBytes;
encodedBytes = c.doFinal(toBeEncryptedString.getBytes("UTF-8"));
return Base64.encode(encodedBytes);
} catch (IllegalBlockSizeException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (BadPaddingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (NoSuchAlgorithmException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (NoSuchPaddingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InvalidKeyException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch ( e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
//通過Pem格式的字元串（PKCS8）生成私鑰，base64是去掉頭和尾的b64編碼的字元串
//Pem格式私鑰一般有2種規范：PKCS8和PKCS1.注意java在生成私鑰時的不同
static PrivateKey generatePrivateKeyFromPKCS8(String base64)
{
byte[] privateKeyBytes;
try {
privateKeyBytes = Base64.decode(base64.getBytes("UTF-8"));
KeyFactory kf = KeyFactory.getInstance("RSA");
PKCS8EncodedKeySpec ks = new PKCS8EncodedKeySpec(privateKeyBytes);
PrivateKey privateKey = kf.generatePrivate(ks);
return privateKey;
} catch (Base64DecodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (NoSuchAlgorithmException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InvalidKeySpecException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
//通過Pem格式的字元串（PKCS1）生成私鑰，base64是去掉頭和尾的b64編碼的字元串
static PrivateKey generatePrivateKeyFromPKCS1(String base64)
{
byte[] privateKeyBytes;
try {
privateKeyBytes = Base64.decode(base64.getBytes("UTF-8"));
KeyFactory kf = KeyFactory.getInstance("RSA");
X509EncodedKeySpec ks = new X509EncodedKeySpec(privateKeyBytes);
PrivateKey privateKey = kf.generatePrivate(ks);
return privateKey;
} catch (Base64DecodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (NoSuchAlgorithmException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InvalidKeySpecException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
//通過Pem格式的字元串（PKCS1）生成公鑰，base64是去掉頭和尾的b64編碼的字元串
//Pem格式公鑰一般採用PKCS1格式
static PublicKey generatePublicKeyFromPKCS1(String base64)
{
byte[] publicKeyBytes;
try {
publicKeyBytes = Base64.decode(base64.getBytes("UTF-8"));
KeyFactory kf = KeyFactory.getInstance("RSA");
X509EncodedKeySpec ks = new X509EncodedKeySpec(publicKeyBytes);
PublicKey publicKey = kf.generatePublic(ks);
return publicKey;
} catch (Base64DecodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (NoSuchAlgorithmException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InvalidKeySpecException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
//通過molus和exponent生成公鑰
//參數含義就是RSA演算法里的意思
public static RSAPublicKey getPublicKey(String molus, String exponent) {
try {
BigInteger b1 = new BigInteger(molus);
BigInteger b2 = new BigInteger(exponent);
KeyFactory keyFactory = KeyFactory.getInstance("RSA");
RSAPublicKeySpec keySpec = new RSAPublicKeySpec(b1, b2);
return (RSAPublicKey) keyFactory.generatePublic(keySpec);
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
Python 代碼
from Config import config
from Crypto.Hash import SHA256
from Crypto.PublicKey import RSA
from Crypto.Cipher import PKCS1_OAEP
key = RSA.generate(1024)
pubkey = key.publickey().key
def Decrypt(prikey,data):
try:
cipher = PKCS1_OAEP.new(prikey, hashAlgo=SHA256)
return cipher.decrypt(data)
except:
traceback.print_exc()
return None
def Encrypt(pubkey,data):
try:
cipher = PKCS1_OAEP.new(pubkey, hashAlgo=SHA256)
return cipher.encrypt(data)
except:
traceback.print_exc()
return None
總結
主要是對RSA演算法不是很熟悉，其中很多術語不懂，導致跟java里的加密模塊的函數和類對應不上。
RSA演算法的細節到現在也是一知半解，但真的沒時間去深入學習了。
㈤ JAVA裡面RSA加密演算法的使用
RSA的Java實現不能一次加密很大的字元，自己處理了一下，見下面的代碼。Base64編碼類用的是一個Public domain Base64 for java http://iharder.sourceforge.net/current/java/base64/其他的保存公鑰到文件等簡單的實現，就不詳細說了，看代碼吧。==============================================import java.security.*;import java.security.spec.PKCS8EncodedKeySpec;import java.security.spec.X509EncodedKeySpec;import java.util.HashMap;import java.util.Map;import javax.crypto.*;import java.io.*;public class Encryptor {private static final String KEY_FILENAME = "c:\\mykey.dat";private static final String OTHERS_KEY_FILENAME = "c:\\Otherskey.dat";// private static final int KEY_SIZE = 1024;// private static final int BLOCK_SIZE = 117;// private static final int OUTPUT_BLOCK_SIZE = 128;private static final int KEY_SIZE = 2048; //RSA key 是多少位的private static final int BLOCK_SIZE = 245; //一次RSA加密操作所允許的最大長度//這個值與 KEY_SIZE 已經padding方法有關。因為 1024的key的輸出是128，2048key輸出是256位元組//可能11個位元組用於保存padding信息了，所以最多可用的就只有245位元組了。private static final int OUTPUT_BLOCK_SIZE = 256;private SecureRandom secrand;private Cipher rsaCipher;private KeyPair keys;private Map<String, Key> allUserKeys;public Encryptor() throws Exception {try {allUserKeys = new HashMap<String, Key>();secrand = new SecureRandom();//SunJCE Provider 中只支持ECB mode，試了一下只有PKCS1PADDING可以直接還原原始數據，//NOPadding導致解壓出來的都是blocksize長度的數據，還要自己處理//參見 http://java.sun.com/javase/6/docs/technotes/guides/security/SunProviders.html#SunJCEProvider////另外根據 Open-JDK-6.b17-src（ http://www.docjar.com/html/api/com/sun/crypto/provider/RSACipher.java.html）// 中代碼的注釋，使用RSA來加密大量數據不是一種標準的用法。所以現有實現一次doFinal調用之進行一個RSA操作，//如果用doFinal來加密超過的一個操作所允許的長度數據將拋出異常。//根據keysize的長度，典型的1024個長度的key和PKCS1PADDING一起使用時//一次doFinal調用只能加密117個byte的數據。（NOPadding 和1024 keysize時128個位元組長度）//（2048長度的key和PKCS1PADDING 最多允許245位元組一次）//想用來加密大量數據的只能自己用其他辦法實現了。可能RSA加密速度比較慢吧，要用AES才行rsaCipher = Cipher.getInstance("RSA/ECB/PKCS1PADDING");} catch (NoSuchAlgorithmException e) {e.printStackTrace();} catch (NoSuchPaddingException e) {e.printStackTrace();throw e;}ObjectInputStream in;try {in = new ObjectInputStream(new FileInputStream(KEY_FILENAME));} catch (FileNotFoundException e) {if (false == GenerateKeys()){throw e;}LoadKeys();return;}keys = (KeyPair) in.readObject();in.close();LoadKeys();}/** 生成自己的公鑰和私鑰*/private Boolean GenerateKeys() {try {KeyPairGenerator keygen = KeyPairGenerator.getInstance("RSA");// secrand = new SecureRandom();// sedSeed之後會造成 生成的密鑰都是一樣的// secrand.setSeed("chatencrptor".getBytes()); // 初始化隨機產生器//key長度至少512長度，不過好像說現在用2048才算比較安全的了keygen.initialize(KEY_SIZE, secrand); // 初始化密鑰生成器keys = keygen.generateKeyPair(); // 生成密鑰組AddKey("me", EncodeKey(keys.getPublic()));} catch (NoSuchAlgorithmException e) {e.printStackTrace();return false;}ObjectOutputStream out;try {out = new ObjectOutputStream(new FileOutputStream(KEY_FILENAME));} catch (IOException e) {e.printStackTrace();return false;}try {out.writeObject(keys);} catch (IOException e) {e.printStackTrace();return false;} finally {try {out.close();} catch (IOException e) {e.printStackTrace();return false;}}return true;}public String EncryptMessage(String toUser, String Message) throws IOException {Key pubkey = allUserKeys.get(toUser);if ( pubkey == null ){throw new IOException("NoKeyForThisUser") ;}try {//PublicKey pubkey = keys.getPublic();rsaCipher.init(Cipher.ENCRYPT_MODE, pubkey, secrand);//System.out.println(rsaCipher.getBlockSize()); 返回0，非block 加密演算法來的？//System.out.println(Message.getBytes("utf-8").length);//byte[] encryptedData = rsaCipher.doFinal(Message.getBytes("utf-8"));byte[] data = Message.getBytes("utf-8");int blocks = data.length / BLOCK_SIZE ;int lastBlockSize = data.length % BLOCK_SIZE ;byte [] encryptedData = new byte[ (lastBlockSize == 0 ? blocks : blocks + 1)* OUTPUT_BLOCK_SIZE];for (int i=0; i < blocks; i++){//int thisBlockSize = ( i + 1 ) * BLOCK_SIZE > data.length ? data.length - i * BLOCK_SIZE : BLOCK_SIZE ;rsaCipher.doFinal(data,i * BLOCK_SIZE, BLOCK_SIZE, encryptedData ,i * OUTPUT_BLOCK_SIZE);}if (lastBlockSize != 0 ){rsaCipher.doFinal(data, blocks * BLOCK_SIZE, lastBlockSize,encryptedData ,blocks * OUTPUT_BLOCK_SIZE);}//System.out.println(encrypted.length); 如果要機密的數據不足128/256位元組，加密後補全成為變為256長度的。//數量比較小時，Base64.GZIP產生的長度更長，沒什麼優勢//System.out.println(Base64.encodeBytes(encrypted,Base64.GZIP).length());//System.out.println(Base64.encodeBytes(encrypted).length());//System.out.println (rsaCipher.getOutputSize(30));//這個getOutputSize 只對 輸入小於最大的block時才能得到正確的結果。其實就是補全 數據為128/256 位元組return Base64.encodeBytes(encryptedData);} catch (InvalidKeyException e) {e.printStackTrace();throw new IOException("InvalidKey") ;}catch (ShortBufferException e) {e.printStackTrace();throw new IOException("ShortBuffer") ;}catch (UnsupportedEncodingException e) {e.printStackTrace();throw new IOException("UnsupportedEncoding") ;} catch (IllegalBlockSizeException e) {e.printStackTrace();throw new IOException("IllegalBlockSize") ;} catch (BadPaddingException e) {e.printStackTrace();throw new IOException("BadPadding") ;}finally {//catch 中 return 或者throw之前都會先調用一下這里}}public String DecryptMessage(String Message) throws IOException {byte[] decoded = Base64.decode(Message);PrivateKey prikey = keys.getPrivate();try {rsaCipher.init(Cipher.DECRYPT_MODE, prikey, secrand);int blocks = decoded.length / OUTPUT_BLOCK_SIZE;ByteArrayOutputStream decodedStream = new ByteArrayOutputStream(decoded.length);for (int i =0 ;i < blocks ; i ++ ){decodedStream.write (rsaCipher.doFinal(decoded,i * OUTPUT_BLOCK_SIZE, OUTPUT_BLOCK_SIZE));}return new String(decodedStream.toByteArray(), "UTF-8");} catch (InvalidKeyException e) {e.printStackTrace();throw new IOException("InvalidKey");} catch (UnsupportedEncodingException e) {e.printStackTrace();throw new IOException("UnsupportedEncoding");} catch (IllegalBlockSizeException e) {e.printStackTrace();throw new IOException("IllegalBlockSize");} catch (BadPaddingException e) {e.printStackTrace();throw new IOException("BadPadding");} finally {// catch 中 return 或者throw之前都會先調用一下這里。}}public boolean AddKey(String user, String key) {PublicKey publickey;try {publickey = DecodePublicKey(key);} catch (Exception e) {return false;}allUserKeys.put(user, publickey);SaveKeys();return true;}private boolean LoadKeys() {BufferedReader input;try {input = new BufferedReader(new InputStreamReader(new FileInputStream(OTHERS_KEY_FILENAME)));} catch (FileNotFoundException e1) {// e1.printStackTrace();return false;}
㈥ JAVA寫RSA加密，公鑰私鑰都是一樣的，為什麼每次加密的結果不一樣
JAVA寫RSA加密，私鑰都是一樣的，公鑰每次加密的結果不一樣跟對數據的padding（填充）有關。
㈦ c#怎麼調用java生成的RSA 公鑰進行加密
.NET無法調用JAVA產生的RSA公鑰，必須將RSA演算法在.NET裡面重寫才行，在.NET裡面RSA的公鑰長度是128位的，但是你給出的JAVA公鑰卻是159位長度，非常的不標准，公鑰長度不滿足128的肯定無法給.NET使用。
這里最多幫做個對應解析，數據是肯定無法用的：
將java的RSA公鑰最後四個字母AQAB分割開，用.NET的xml格式表示就是
<RSAKeyValue><Molus>
/qp
jLFfDCu3qytxf+/IoCYE
+Hf4hsEDUKV2kkhRJsnwwID</Molus><Exponent>AQAB</Exponent>
</RSAKeyValue>
這里的數據都是用的BASE64編碼，你用BASE64解碼後可以得到byte[]，就可以看到密鑰長度了，實際密鑰要轉換為BigInteger後才能參與RSA核心運算
㈧ 怎樣用Java實現RSA加密
提供加密，解密，生成密鑰對等方法。�梢願�模��遣灰��螅�裨蛐�駛岬� keyPairGen.initialize(KEY_SIZE, new SecureRandom()); KeyPair keyPair = keyPairGen.genKeyPair(); return keyPair; } catch (Exception e) { throw new Exception(e.getMessage()); } } /** * 生成公鑰 * @param molus * @param publicExponent * @return RSAPublicKey * @throws Exception */ public static RSAPublicKey generateRSAPublicKey(byte[] molus, byte[] publicExponent) throws Exception { KeyFactory keyFac = null; try { keyFac = KeyFactory.getInstance("RSA", new org.bouncycastle.jce.provider.BouncyCastleProvider()); } catch (NoSuchAlgorithmException ex) { throw new Exception(ex.getMessage()); } RSAPublicKeySpec pubKeySpec = new RSAPublicKeySpec(new BigInteger(molus), new BigInteger(publicExponent)); try { return (RSAPublicKey) keyFac.generatePublic(pubKeySpec); } catch (InvalidKeySpecException ex) { throw new Exception(ex.getMessage()); } } /** * 生成私鑰 * @param molus * @param privateExponent * @return RSAPrivateKey * @throws Exception */ public static RSAPrivateKey generateRSAPrivateKey(byte[] molus, byte[] privateExponent) throws Exception { KeyFactory keyFac = null; try { keyFac = KeyFactory.getInstance("RSA", new org.bouncycastle.jce.provider.BouncyCastleProvider()); } catch (NoSuchAlgorithmException ex) { throw new Exception(ex.getMessage()); } RSAPrivateKeySpec priKeySpec = new RSAPrivateKeySpec(new BigInteger(molus), new BigInteger(privateExponent)); try { return (RSAPrivateKey) keyFac.generatePrivate(priKeySpec); } catch (InvalidKeySpecException ex) { throw new Exception(ex.getMessage()); } } /** * 加密 * @param key 加密的密鑰 * @param data 待加密的明文數據 * @return 加密後的數據 * @throws Exception */ public static byte[] encrypt(Key key, byte[] data) throws Exception { try { Cipher cipher = Cipher.getInstance("RSA", new org.bouncycastle.jce.provider.BouncyCastleProvider()); cipher.init(Cipher.ENCRYPT_MODE, key); int blockSize = cipher.getBlockSize();//獲得加密塊大小� i++; } return raw; } catch (Exception e) { throw new Exception(e.getMessage()); } } /** * 解密 * @param key 解密的密鑰 * @param raw 已經加密的數據 * @return 解密後的明文 * @throws Exception */ public static byte[] decrypt(Key key, byte[] raw) throws Exception { try { Cipher cipher = Cipher.getInstance("RSA", new org.bouncycastle.jce.provider.BouncyCastleProvider()); cipher.init(cipher.DECRYPT_MODE, key); int blockSize = cipher.getBlockSize(); ByteArrayOutputStream bout = new ByteArrayOutputStream(64); int j = 0; while (raw.length - j * blockSize > 0) { bout.write(cipher.doFinal(raw, j * blockSize, blockSize)); j++; } return bout.toByteArray(); } catch (Exception e) { throw new Exception(e.getMessage()); } } /** * * @param args * @throws Exception */ public static void main(String[] args) throws Exception { File file = new File("c:/test.html"); FileInputStream in = new FileInputStream(file); ByteArrayOutputStream bout = new ByteArrayOutputStream(); byte[] tmpbuf = new byte[1024]; int count = 0; while ((count = in.read(tmpbuf)) != -1) { bout.write(tmpbuf, 0, count); tmpbuf = new byte[1024]; } in.close(); byte[] orgData = bout.toByteArray(); KeyPair keyPair = RSA.generateKeyPair(); RSAPublicKey pubKey = (RSAPublicKey) keyPair.getPublic(); RSAPrivateKey priKey = (RSAPrivateKey) keyPair.getPrivate(); byte[] pubModBytes = pubKey.getMolus().toByteArray(); byte[] pubPubExpBytes = pubKey.getPublicExponent().toByteArray(); byte[] priModBytes = priKey.getMolus().toByteArray(); byte[] priPriExpBytes = priKey.getPrivateExponent().toByteArray(); RSAPublicKey recoveryPubKey = RSA.generateRSAPublicKey(pubModBytes,pubPubExpBytes); RSAPrivateKey recoveryPriKey = RSA.generateRSAPrivateKey(priModBytes,priPriExpBytes); byte[] raw = RSA.encrypt(priKey, orgData); file = new File("c:/encrypt_result.dat"); OutputStream out = new FileOutputStream(file); out.write(raw); out.close(); byte[] data = RSA.decrypt(recoveryPubKey, raw); file = new File("c:/decrypt_result.html"); out = new FileOutputStream(file); out.write(data); out.flush(); out.close(); } } （責任編輯：雲子）
㈨ rsa加密演算法 java
代碼如下：main方法用於測試的，不是演算法本身。
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.SecureRandom;
import javax.crypto.Cipher;
public class RSACrypto
{
private final static String RSA = "RSA";
public static PublicKey uk;
public static PrivateKey rk;
public static void generateKey() throws Exception
{
KeyPairGenerator gen = KeyPairGenerator.getInstance(RSA);
gen.initialize(512, new SecureRandom());
KeyPair keyPair = gen.generateKeyPair();
uk = keyPair.getPublic();
rk = keyPair.getPrivate();
}
private static byte[] encrypt(String text, PublicKey pubRSA) throws Exception
{
Cipher cipher = Cipher.getInstance(RSA);
cipher.init(Cipher.ENCRYPT_MODE, pubRSA);
return cipher.doFinal(text.getBytes());
}
public final static String encrypt(String text)
{
try {
return byte2hex(encrypt(text, uk));
}
catch(Exception e)
{
e.printStackTrace();
}
return null;
}
public final static String decrypt(String data)
{
try{
return new String(decrypt(hex2byte(data.getBytes())));
}
catch (Exception e)
{
e.printStackTrace();
}
return null;
}
private static byte[] decrypt(byte[] src) throws Exception
{
Cipher cipher = Cipher.getInstance(RSA);
cipher.init(Cipher.DECRYPT_MODE, rk);
return cipher.doFinal(src);
}
public static String byte2hex(byte[] b)
{
String hs = "";
String stmp = "";
for (int n = 0; n < b.length; n ++)
{
stmp = Integer.toHexString(b[n] & 0xFF);
if (stmp.length() == 1)
hs += ("0" + stmp);
else
hs += stmp;
}
return hs.toUpperCase();
}
public static byte[] hex2byte(byte[] b)
{
if ((b.length % 2) != 0)
throw new IllegalArgumentException("長度不是偶數");
byte[] b2 = new byte[b.length / 2];
for (int n = 0; n < b.length; n += 2)
{
String item = new String(b, n, 2);
b2[n/2] = (byte)Integer.parseInt(item, 16);
}
return b2;
}
//just for test
public static void main(String args[])
{
try
{
RSACrypto.generateKey();
String cipherText = RSACrypto.encrypt("asdfghjh");
System.out.println(cipherText);
String plainText = RSACrypto.decrypt(cipherText);
System.out.println(plainText);
}
catch(Exception e)
{
e.printStackTrace();
}
}
}
求採納為滿意回答。
㈩ Java 第三方公鑰 RSA加密求助
下面是RSA加密代碼。
/**
* RSA演算法，實現數據的加密解密。
* @author ShaoJiang
*
*/
public class RSAUtil {
private static Cipher cipher;
static{
try {
cipher = Cipher.getInstance("RSA");
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (NoSuchPaddingException e) {
e.printStackTrace();
}
}
/**
* 生成密鑰對
* @param filePath 生成密鑰的路徑
* @return
*/
public static Map<String,String> generateKeyPair(String filePath){
try {
KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance("RSA");
// 密鑰位數
keyPairGen.initialize(1024);
// 密鑰對
KeyPair keyPair = keyPairGen.generateKeyPair();
// 公鑰
PublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
// 私鑰
PrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
//得到公鑰字元串
String publicKeyString = getKeyString(publicKey);
//得到私鑰字元串
String privateKeyString = getKeyString(privateKey);
//將密鑰對寫入到文件 想學習更多加我q u N 前面是二五七 中間是014後面是001
FileWriter pubfw = new FileWriter(filePath+"/publicKey.keystore");
FileWriter prifw = new FileWriter(filePath+"/privateKey.keystore");
BufferedWriter pubbw = new BufferedWriter(pubfw);
BufferedWriter pribw = new BufferedWriter(prifw);
pubbw.write(publicKeyString);
pribw.write(privateKeyString);
pubbw.flush();
pubbw.close();
pubfw.close();
pribw.flush();
pribw.close();
prifw.close();
//將生成的密鑰對返回
Map<String,String> map = new HashMap<String,String>();
map.put("publicKey",publicKeyString);
map.put("privateKey",privateKeyString);
return map;
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
/**
* 得到公鑰
*
* @param key
* 密鑰字元串（經過base64編碼）
* @throws Exception
*/
public static PublicKey getPublicKey(String key) throws Exception {
byte[] keyBytes;
keyBytes = (new BASE64Decoder()).decodeBuffer(key);
X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance("RSA");
PublicKey publicKey = keyFactory.generatePublic(keySpec);
return publicKey;
}
/**
* 得到私鑰
*
* @param key
* 密鑰字元串（經過base64編碼）
* @throws Exception
*/
public static PrivateKey getPrivateKey(String key) throws Exception {
byte[] keyBytes;
keyBytes = (new BASE64Decoder()).decodeBuffer(key);
PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance("RSA");
PrivateKey privateKey = keyFactory.generatePrivate(keySpec);
return privateKey;
}
/**
* 得到密鑰字元串（經過base64編碼）
*
* @return
*/
public static String getKeyString(Key key) throws Exception {
byte[] keyBytes = key.getEncoded();
String s = (new BASE64Encoder()).encode(keyBytes);
return s;
}
/**
* 使用公鑰對明文進行加密，返回BASE64編碼的字元串
* @param publicKey
* @param plainText
* @return
*/
public static String encrypt(PublicKey publicKey,String plainText){
try {
cipher.init(Cipher.ENCRYPT_MODE, publicKey);
byte[] enBytes = cipher.doFinal(plainText.getBytes());
return (new BASE64Encoder()).encode(enBytes);
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
e.printStackTrace();
}
return null;
}
/**
* 使用keystore對明文進行加密
* @param publicKeystore 公鑰文件路徑
* @param plainText 明文
* @return
*/
public static String encrypt(String publicKeystore,String plainText){
try {
FileReader fr = new FileReader(publicKeystore);
BufferedReader br = new BufferedReader(fr);
String publicKeyString="";
String str;
while((str=br.readLine())!=null){
publicKeyString+=str;
}
br.close();
fr.close();
cipher.init(Cipher.ENCRYPT_MODE,getPublicKey(publicKeyString));
byte[] enBytes = cipher.doFinal(plainText.getBytes());
return (new BASE64Encoder()).encode(enBytes);
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
/**
* 使用私鑰對明文密文進行解密
* @param privateKey
* @param enStr
* @return
*/
public static String decrypt(PrivateKey privateKey,String enStr){
try {
cipher.init(Cipher.DECRYPT_MODE, privateKey);
byte[] deBytes = cipher.doFinal((new BASE64Decoder()).decodeBuffer(enStr));
return new String(deBytes);
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
/**
* 使用keystore對密文進行解密
* @param privateKeystore 私鑰路徑
* @param enStr 密文
* @return
*/
public static String decrypt(String privateKeystore,String enStr){
try {
FileReader fr = new FileReader(privateKeystore);
BufferedReader br = new BufferedReader(fr);
String privateKeyString="";
String str;
while((str=br.readLine())!=null){
privateKeyString+=str;
}
br.close();
fr.close();
cipher.init(Cipher.DECRYPT_MODE, getPrivateKey(privateKeyString));
byte[] deBytes = cipher.doFinal((new BASE64Decoder()).decodeBuffer(enStr));
return new String(deBytes);
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
}