Import? org . Apache . commons . codec . binary . base64；
Import? javax . crypto . badpaddingexception；
Import? javax . crypto . cipher；
Import? javax . crypto . illegalblocksizeexception；
Import? Java . io . bytearrayoutputstream；
Import? Java . io . unsupportedencodingexception；
Import? Java . security . *；
Import? Java . security . interfaces . rsaprivatekey；
Import? Java . security . interfaces . RSA public key；
Import? Java . security . spec . pkcs 8 encodedkeyspec；
Import? Java . security . spec . x 509 encodedkeyspec；
Public? Class? RSAUtils？ {
//? Encryption mode
Public? Static electricity Final? String? Algorithm? =? ”RSA”；
//? Signature algorithm
Private? Static electricity Final? String? Signature _ algorithm? =? ”sha 1 with RSA”；
//? Create the initial length of the key pair
Private? Static electricity Final? int？ KEY_SIZE？ =? 5 12;
//? Character encoding format
Private? Static electricity Final? String? Character set? =? “UTF-8”；
//? RSA maximum encrypted plaintext size
Private? Static electricity Final? int？ MAX_ENCRYPT_BLOCK？ =? 1 17;
//? Maximum decryption ciphertext length of RSA
Private? Static electricity Final? int？ MAX_DECRYPT_BLOCK？ =? 128;
Private? KeyFactory？ keyFactory
Public? RSAUtils()？ Throwing? NoSuchAlgorithmException？ {
keyFactory？ =? KeyFactory.getInstance (algorithm);
}
/**
*? Private key encryption
*
*? @param？ The content string to encrypt.
*? @param？ privateKey？ Private key
*? @ Return? Encrypted string (BASE64 encoding)
*/
Public? String? EncryptByPrivateKey (string? Content? String? privateKey)？ Throwing? Exceptions? {
String? Results;
Try it? (ByteArrayOutputStream？ Out? =? New? ByteArrayOutputStream())？ {
byte[]？ keyBytes？ =? New? Base64()。 decode(private key)；
PKCS8EncodedKeySpec？ pkcs8KeySpec？ =? New? pkcs 8 encodedkeyspec(key bytes)；
PrivateKey？ pKey？ =? key factory . generate private(pkcs 8 key spec)；
Password? Password? =? Cipher.getInstance (algorithm);
Cipher.init (password. Encryption mode? pKey)；
byte[]？ Data? =? content . getbytes(CHARSET)；
Write2Stream (password,? Data? out)；
byte[]？ Result bytes? =? out . tobytearray()；
The result? =? base64 . encode base 64 string(result bytes)；
}? Catch? (exception? e)？ {
Throw? New? Exception (e);
}
Return? Results;
}
/**
*? Public key decryption
*
*? @param？ Content encrypted string (BASE64 encrypted)
*? @param？ Public key? Public key
*? @ Return
*/
Public? String? DecryptByPublicKey (string? Content? String? publicKey)？ Throwing? Exceptions? {
String? The result? =? "";
Try it? (ByteArrayOutputStream？ Out? =? New? ByteArrayOutputStream())？ {
byte[]？ keyBytes？ =? New? Base64()。 decode(public key)；
X509EncodedKeySpec？ x509KeySpec？ =? New? x 509 encodedkeyspec(key bytes)；
Public key? pKey？ =? key factory . generate public(x509 key spec)；
Password? Password? =? Cipher.getInstance (algorithm);
Cipher.init (password. Decryption mode? pKey)；
byte[]？ Data? =? Base64.decodeBase64 (content);
Write2Stream (password,? Data? out)；
byte[]？ Result bytes? =? out . tobytearray()；
The result? =? New? String (result bytes);
}? Catch? (exception? e)？ {
Throw? New? Exception (e);
}
Return? Results;
}
/**
*? Public key encryption
*
*? @param？ The content string to encrypt.
*? @param？ Public key? Public key
*? @ Return? Encrypted string (BASE64 encoding)
*/
Public? String? EncryptByPublicKey (string? Content? String? publicKey)？ Throwing? Exceptions? {
String? The result? =? "";
Try it? (ByteArrayOutputStream？ Out? =? New? ByteArrayOutputStream())？ {
byte[]？ keyBytes？ =? New? Base64()。 decode(public key)；
X509EncodedKeySpec？ x509KeySpec？ =? New? x 509 encodedkeyspec(key bytes)；
Public key? pKey？ =? key factory . generate public(x509 key spec)；
Password? Password? =? Cipher.getInstance (algorithm);
Cipher.init (password. Encryption mode? pKey)；
byte[]？ Data? =? content . getbytes(CHARSET)；
Write2Stream (password,
Data? out)；
byte[]？ Result bytes? =? out . tobytearray()；
The result? =? base64 . encode base 64 string(result bytes)；
}? Catch? (exception? e)？ {
Throw? New? Exception (e);
}
Return? Results;
}
/**
*? Private key decryption
*
*? @param？ Content encrypted string
*? @param？ privateKey？ Private key
*? @ Return? Decrypted string
*/
Public? String? DecryptByPrivateKey (string? Content? String? privateKey)？ Throwing? Exceptions? {
String? The result? =? "";
Try it? (ByteArrayOutputStream？ Out? =? New? ByteArrayOutputStream())？ {
byte[]？ keyBytes？ =? New? Base64()。 decode(private key)；
PKCS8EncodedKeySpec？ pkcs8KeySpec？ =? New? pkcs 8 encodedkeyspec(key bytes)；
PrivateKey？ pKey？ =? key factory . generate private(pkcs 8 key spec)；
Password? Password? =? Cipher.getInstance (algorithm);
Cipher.init (password. Decryption mode? pKey)；
byte[]？ Data? =? Base64.decodeBase64 (content);
Write2Stream (password,? Data? out)；
byte[]？ Result bytes? =? out . tobytearray()；
The result? =? New? String (result bytes);
}? Catch? (exception? e)？ {
Throw? New? Exception (e);
}
Return? Results;
}
Private? Static electricity Invalid? Write2Stream (password? Password? byte[]？ Data? ByteArrayOutputStream？ Out)? throw
BadPaddingException，？ IllegalBlockSizeException？ {
int？ D 'Artalen? =? Data length;
int？ Offset? =? 0;
byte[]？ Caching;
int？ Me? =? 0;
//? Decrypt data segment
What time? (dataLen？ -? Offset? & gt？ 0)? {
What if? (dataLen？ -? Offset? & gt？ MAX_DECRYPT_BLOCK)？ {
Caching? =? cipher.doFinal(data，？ Offset? Maximum decryption block);
}? Or what? {
Caching? =? cipher.doFinal(data，？ Offset? D 'Artalen? -? Offset);
}
Out.write (cache,? 0,? cache . length)；
i++；
Offset? =? Me? *? Maximum decryption block;
}
}
/**
*? Generate a digital signature on information with a private key.
*
*? @param？ Data encryption data
*? @param？ privateKey？ Private key (BASE64 encoding)
*? @ Return? symbol
*/
Public? String? Symbol (string? Data? String? privateKey)？ Throwing? Exceptions? {
String? The result? =? "";
Try it? {
byte[]？ keyBytes？ =? New? Base64()。 decode(private key)；
PKCS8EncodedKeySpec？ pkcs8KeySpec？ =? New? pkcs 8 encodedkeyspec(key bytes)；
PrivateKey？ privateK？ =? key factory . generate private(pkcs 8 key spec)；
Signature? Signature? =? SIGNATURE . getinstance(SIGNATURE _ ALGORITHM)；
signature . init sign(privateK)；
signature . update(parse 2 hex str(data))。 getBytes(CHARSET))；
The result? =? New? Base64()。 encodeToString(signature . sign())；
}? Catch? (exception? e)？ {
Throw? New? Exception (e);
}
Return? Results;
}
/**
*? Check digital signature
*
*? @param？ Data? enciphered data
*? @param？ Public key? Public key (BASE64 encoding)
*? @param？ Sign? digital signature
*? @ Return
*? @throws？ exception
*/
Public? Bull? Verification (string? Data? String? Public key? String? Sign)? Throwing? Exceptions? {
Bull? Results;
Try it? {
byte[]？ keyBytes？ =? New? Base64()。 decode(public key)；
X509EncodedKeySpec？ keySpec？ =? New? x 509 encodedkeyspec(key bytes)；
Public key? publicK？ =? key factory . generate public(key spec)；
Signature? Signature? =? SIGNATURE . getinstance(SIGNATURE _ ALGORITHM)；
signature . init verify(publicK)；
signature . update(parse 2 hex str(data))。 getBytes(CHARSET))；
The result? =? Signature.verify (new? Base64()。 Decode (symbol));
}? Catch? (exception? e)？ {
Throw? New? Exception (e);
}
Return? Results;
}
/**
*? Convert binary to 16.
*
*? @param？ data
*? @ Return
*/
Public? Static electricity String? Parse2HexStr (string? Data)? Throwing? Exceptions? {
String? The result? =? "";
Try it? {
byte[]？ buf？ =? data . getbytes(CHARSET)；
StringBuffer？ sb？ =? New? string buffer()；
For what? (int？ Me? =? 0; ? Me? & lt？ Buf. length; ? i++)？ {
String? Black magic? =? Integer.toHexString(buf[i]？ & amp？ 0x ff)；
What if? (hex.length()？ ==? 1)? {
Black magic? =? '0'? +? Hexadecimal;
}
sb . append(hex . toupper case())；
}
The result? =? sb . tostring()；
}? Catch? (UnsupportedEncodingException？ e)？ {
Throw? New? Exception (e);
}
Return? Results;
}
/**
*? Generate public and private keys
*/
Public? Static electricity Invalid? createKey()？ Throwing? Exceptions? {
Try it? {
KeyPairGenerator？ keyPairGenerator？ =? KeyPairGenerator.getInstance (algorithm);
keypairgenerator . initialize(KEY _ SIZE)；
KeyPair？ keyPair？ =? keypairgenerator . generatekeypair()；
RSAPublicKey？ rsaPublicKey？ =? (RSAPublicKey)？ key pair . get public()；
RSAPrivateKey？ rsaPrivateKey？ =? (RSAPrivateKey)？ key pair . get private()；
String? Public key? =? base64 . encode base 64 string(RSA public key . get encoded())；
String? privateKey？ =? base64 . encode base 64 string(rsaprivatekey . get encoded())；
System.out.println("publicKey= "？ +? Public key? +? " \nprivateKey= "？ +? private key)；
}? Catch? (NoSuchAlgorithmException？ e)？ {
Throw? New? Exception (e);
}
}
Public? Static electricity Invalid? main(String[]？ args)？ Throwing? Exceptions? {
String? PRIVATE_KEY？ =? " miiceaibadangbgkqhkig 9 w 0 baqefaascamiwggjeageaogbakeygxh 6 vz+m+kul 1 1 rdrandhb 4 yqezgqpjgprswbelgveohu 2/fns 1 bmgfjhi 8 lhr/o/hy 8 efb/I/ddylcccu 4 bcltxpki 8 EDC+kjr 2 wvyyfnnvmwee/3q 2 jsvkrf 8 1
String? Public key? =? " MIG fma 0 gcsqgsib 3d qebaquaa 4 gnadcbiqkbgqcnmblx+LC/pviri 9 du Q0 wjxrweghmyqsrj 0 usaxpyl xkb 7 TV 3 zbn w5 hyyspjya/ 6px 8 vbbqfypw8 i3 anfogwi 7 cazivhnqviudlr 8 MH 5 1 zlhhv 96 to 0 lskx/nfovkvqndzdh 60 zlgomde 0 NBR TN/5 zejgwjbvdlvcfoi
RSAUtils？ rsaUtil？ =? New? RSAUtils()；
String? encryptByPublicKey？ =? RSA util . encryptbypublickey(" Hello！" ,? PUBLIC _ KEY)；
system . out . println(encryptByPublicKey)；
String? decryptByPrivateKey？ =? RSA util . decryptbyprivatekey(encryptByPublicKey，？ PRIVATE _ KEY)；
system . out . println(decryptByPrivateKey)；
String? encryptByPrivateKey？ =? RSA util . encryptbyprivatekey(" Hello！" ,? PRIVATE _ KEY)；
system . out . println(encryptByPrivateKey)；
String? decryptByPublicKey？ =? RSA util . decryptbypublickey(encryptByPrivateKey，？ PUBLIC _ KEY)；
system . out . println(decryptByPublicKey)；
String? Sign? =? rsaUtil.sign(" 1234 "，PRIVATE _ KEY)；
System.out.println("sign:"？ +? Signature);
System. out.println (rsautil.verify ("1234"), public key? Signature));
}
}