java.lang.Object
javax.crypto.Cipher
- Direct Known Subclasses:
- NullCipher
- See Also:
- Top Examples, Source Code,
KeyGenerator,
SecretKey
protected Cipher(CipherSpi cipherSpi,
Provider provider,
String transformation)- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
[528]AES encryption
By Anonymous on 2004/08/09 17:18:10 Rate
import java.security.*;
importjavax.crypto.*;
// Get Provider
Provider sunJce = new com.sun.crypto.provider.SunJCE ( ) ;
// Obtain Cipher AES available 1.4.2
Cipher c = Cipher.getInstance ( "AES" ) ;
// Get the key Generator
KeyGenerator kgen = KeyGenerator.getInstance ( "AES" ) ;
// Generate the key specs
SecretKey skey = kgen.generateKey ( ) ;
byte [ ] raw = skey.getEncoded ( ) ;
SecretKeySpec kspec = new
SecretKeySpec ( raw, "AES" ) ;
// Initialize cipher with keys, etc.
cipher.init ( Cipher.ENCRYPT_MODE, kspec ) ;
// Update buffers
while ( msg [ i ] != null )
enc = cipher.update ( msg [ i ] .getBytes ( ) ) ;
// Finish up
enc = cipher.doFinal ( ) ;[2020]cipher
By agazi_a { at } yahoo { dot } com on 2012/02/20 06:18:29 Rate
import java.security.*;
import javax.crypto.*;
import javax.crypto.spec.*;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.Cipher;
import java.io.*;
import javax.*;
public class encryptTest {
public static void main ( String [ ] args ) throws Exception
{
FileInputStream in = null;
FileOutputStream out = null;
byte [ ] key = { 0,2,3,4,5,6,7,8,9,1,2,3,4,5,6,7 } ;//... secret sequence of bytes
System.out.println ( "Please type the word to be encrypted" ) ;
String sentence;
BufferedReader inFromUser =
new BufferedReader ( new InputStreamReader ( System.in ) ) ;
sentence = inFromUser.readLine ( ) ;
byte [ ] dataToSend =sentence.getBytes ( ) ;
//out = new FileOutputStream ( "plain.txt" ) ;
//out.write ( dataToSend ) ;
//out.close ( ) ;
String st = new String ( dataToSend ) ;
System.out.println ( "Plain text data to be encrypted: " +st ) ;
Cipher ci = Cipher.getInstance ( "AES" ) ;
SecretKeySpec ky =
new SecretKeySpec ( key, "AES" ) ;
ci.init ( Cipher.ENCRYPT_MODE, ky ) ;
byte [ ] encryptedData = ci.doFinal ( dataToSend ) ;
//String str =new String ( encryptedData ) ;
//System.out.println ( "Cipher text data to be send to receiver: " //+str ) ;
FileOutputStream sot = new FileOutputStream ( "encryptedfile.txt" ) ;
sot.write ( encryptedData ) ;
FileOutputStream ou = new FileOutputStream ( "plains.txt" ) ;
ou.write ( dataToSend ) ;
MessageDigest md = MessageDigest.getInstance ( "MD5" ) ;
FileInputStream fis = new FileInputStream ( "plains.txt" ) ;
byte [ ] dataBytes = new byte [ 1024 ] ;
int nread = 0;
while ( ( nread = fis.read ( dataBytes ) ) != -1 ) {
md.update ( dataBytes, 0, nread ) ;
} ;
byte [ ] mdbytes = md.digest ( ) ;
//convert the byte to hex format method 1
StringBuffer sb = new StringBuffer ( ) ;
for ( int i = 0; i < mdbytes.length; i++ ) {
sb.append ( Integer.toString ( ( mdbytes [ i ] & 0xff ) + 0x100, 16 ) .substring ( 1 ) ) ;
}
System.out.println ( "Digest ( in hex format ) :: " + sb.toString ( ) ) ;
fis.close ( ) ;
Cipher c = Cipher.getInstance ( "AES" ) ;
SecretKeySpec k =
new SecretKeySpec ( key, "AES" ) ;
c.init ( Cipher.ENCRYPT_MODE, k ) ;
byte [ ] md5encryptedData = c.doFinal ( mdbytes ) ;
//String str =new String ( encryptedData ) ;
//System.out.println ( "Cipher text data to be send to receiver: " //+str ) ;
FileOutputStream ot = new FileOutputStream ( "md5encryptedfile.txt" ) ;
ot.write ( md5encryptedData ) ;
}
}
decryption
import java.security.*;
import javax.crypto.*;
import javax.crypto.spec.*;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.Cipher;
import java.io.*;
import javax.*;
import java.io.File;
public class decryptTest {
public static void main ( String [ ] args ) throws Exception {
byte [ ] key = { 0,2,3,4,5,6,7,8,9,1,2,3,4,5,6,7 } ;
byte [ ] buffer = new byte [ ( int ) new File ( "encryptedfile.txt" ) .length ( ) ] ;
FileInputStream is = new FileInputStream ( "encryptedfile.txt" ) ;
is.read ( buffer ) ;
Cipher c = Cipher.getInstance ( "AES" ) ;
SecretKeySpec k =
new SecretKeySpec ( key, "AES" ) ;
c.init ( Cipher.DECRYPT_MODE, k ) ;
byte [ ] data = c.doFinal ( buffer ) ;
FileOutputStream out = new FileOutputStream ( "plain.txt" ) ;
out.write ( data ) ;
out.close ( ) ;
byte [ ] buf = new byte [ ( int ) new File ( "md5encryptedfile.txt" ) .length ( ) ] ;
FileInputStream in = new FileInputStream ( "md5encryptedfile.txt" ) ;
in.read ( buf ) ;
Cipher ci = Cipher.getInstance ( "AES" ) ;
SecretKeySpec ky =
new SecretKeySpec ( key, "AES" ) ;
ci.init ( Cipher.DECRYPT_MODE, ky ) ;
byte [ ] mddata = ci.doFinal ( buf ) ;
//convert the byte to hex format method 1
StringBuffer sb = new StringBuffer ( ) ;
for ( int i = 0; i < mddata.length; i++ ) {
sb.append ( Integer.toString ( ( mddata [ i ] & 0xff ) + 0x100, 16 ) .substring ( 1 ) ) ;
}
System.out.println ( "Digest ( in hex format ) :: " + sb.toString ( ) ) ;
String sb1=sb.toString ( ) ;
MessageDigest md = MessageDigest.getInstance ( "MD5" ) ;
FileInputStream fis = new FileInputStream ( "plain.txt" ) ;
byte [ ] dataBytes = new byte [ 1024 ] ;
int nread = 0;
while ( ( nread = fis.read ( dataBytes ) ) != -1 ) {
md.update ( dataBytes, 0, nread ) ;
} ;
byte [ ] mdbytes = md.digest ( ) ;
//convert the byte to hex format method 1
StringBuffer st = new StringBuffer ( ) ;
for ( int i = 0; i < mdbytes.length; i++ ) {
st.append ( Integer.toString ( ( mdbytes [ i ] & 0xff ) + 0x100, 16 ) .substring ( 1 ) ) ;
}
System.out.println ( "Digest ( in hex format ) :: " + st.toString ( ) ) ;
String st1=st.toString ( ) ;
boolean bool=st1.equals ( sb1 ) ;
System.out.println ( "Compared the decrypted hashed value with hashed value and the result is:"+bool+"\nTherefore the integrity of the message is confirmed" ) ;
}
}
public static final int DECRYPT_MODE
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final byte[] doFinal()
throws IllegalBlockSizeException,
BadPaddingException- See Also:
- IllegalStateException
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
[743]Decrypt string
By rajganeshnaidu { at } yahoo { dot } com on 2004/04/23 04:22:29 Rate
public static String decryptString ( String inputString )
{
try
{
Security.addProvider ( new ABAProvider ( ) ) ;
ObjectInputStream in = new ObjectInputStream ( new FileInputStream ( SystemManager.get ( "db.key" ) ) ) ;
Key key = ( Key ) in.readObject ( ) ;
in.close ( ) ;
Cipher cipher = Cipher.getInstance ( "DESede/ECB/PKCS5Padding" ) ;
cipher.init ( 2, key ) ;
BASE64Decoder decoder = new BASE64Decoder ( ) ;
byte inputBytes [ ] = decoder.decodeBuffer ( inputString ) ;
String result=null;
try {
byte outputBytes [ ] = cipher.doFinal ( inputBytes ) ;
result = new String ( outputBytes, "UTF8" ) ;
System.out.println ( "\n\n result is: " + result + "\n\n" ) ;
} catch ( Exception e ) {
System.out.println ( "\nNaidu, problem in calling cipher.doFinal method\n\n" ) ;
System.out.println ( e.toString ( ) ) ;
} ;
//String result = new String ( outputBytes, "UTF8" ) ;
return result;
}
catch ( Exception e )
{
LogManager.logError ( "Unable to decrypt input string.", e ) ;
}
return null;
}
}
public final byte[] doFinal(byte[] input)
throws IllegalBlockSizeException,
BadPaddingException- See Also:
- IllegalStateException
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final int doFinal(byte[] output,
int outputOffset)
throws IllegalBlockSizeException,
ShortBufferException,
BadPaddingException- See Also:
- IllegalStateException,
getOutputSize
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
[1565]Encrypt larger data
By Anonymous on 2005/10/08 18:10:23 Rate
//This piece of code could give you javax.crypto.IllegalBlockSizeException: Data must not be longer than 245 bytes
Cipher cipher = Cipher.getInstance ( "RSA" ) ;
cipher.init ( Cipher.ENCRYPT_MODE, rsaPublic ) ;
encryptedData = cipher.doFinal ( originalData ) ;
//The RSA algorithm can only encrypt data that has a maximum byte length of the RSA key length in bits divided with eight minus eleven padding bytes, i.e. number of maximum bytes = key length in bits / 8 - 11. In your case it means 2048 / 8 - 11 = 245. If you want to encrypt larger data, then use a larger key, for example, a key with 4096 bits will allow you to encrypt 501 bytes of data.
public final byte[] doFinal(byte[] input,
int inputOffset,
int inputLen)
throws IllegalBlockSizeException,
BadPaddingException- See Also:
- IllegalStateException
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final int doFinal(byte[] input,
int inputOffset,
int inputLen,
byte[] output)
throws ShortBufferException,
IllegalBlockSizeException,
BadPaddingException- See Also:
- IllegalStateException,
getOutputSize
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final int doFinal(byte[] input,
int inputOffset,
int inputLen,
byte[] output,
int outputOffset)
throws ShortBufferException,
IllegalBlockSizeException,
BadPaddingException- See Also:
- IllegalStateException,
getOutputSize
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final int doFinal(ByteBuffer input,
ByteBuffer output)
throws ShortBufferException,
IllegalBlockSizeException,
BadPaddingException- See Also:
- ReadOnlyBufferException, IllegalArgumentException, IllegalStateException,
getOutputSize
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public static final int ENCRYPT_MODE
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final String getAlgorithm()
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final int getBlockSize()
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final ExemptionMechanism getExemptionMechanism()
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public static final Cipher getInstance(String transformation)
throws NoSuchAlgorithmException,
NoSuchPaddingException- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
[1560]Add a new security provider
By Anonymous on 2005/10/07 05:25:11 Rate
//add a new security provider
import org.bouncycastle.jce.provider.BouncyCastleProvider;
java.security.Security.addProvider ( new org.bouncycastle.jce.provider.BouncyCastleProvider ( ) ) ;
Cipher c = Cipher.getInstance ( "RSA/ECB/PKCS1Padding", "BC" ) ;
public static final Cipher getInstance(String transformation,
String provider)
throws NoSuchAlgorithmException,
NoSuchProviderException,
NoSuchPaddingException- See Also:
- IllegalArgumentException
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public static final Cipher getInstance(String transformation,
Provider provider)
throws NoSuchAlgorithmException,
NoSuchPaddingException- See Also:
- IllegalArgumentException
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final byte[] getIV()
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public static final int getMaxAllowedKeyLength(String transformation)
throws NoSuchAlgorithmException- See Also:
- NullPointerException
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public static final AlgorithmParameterSpec getMaxAllowedParameterSpec(String transformation)
throws NoSuchAlgorithmException- See Also:
- NullPointerException
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final int getOutputSize(int inputLen)
- See Also:
- IllegalStateException
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final AlgorithmParameters getParameters()
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final Provider getProvider()
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final void init(int opmode,
Certificate certificate)
throws InvalidKeyException- See Also:
-
getIV, getParameters
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final void init(int opmode,
Certificate certificate,
SecureRandom random)
throws InvalidKeyException- See Also:
-
getIV, getParameters
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final void init(int opmode,
Key key)
throws InvalidKeyException- See Also:
-
SecureRandomgetIV, getParameters
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final void init(int opmode,
Key key,
AlgorithmParameters params)
throws InvalidKeyException,
InvalidAlgorithmParameterException- See Also:
-
SecureRandomgetIV, getParameters
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final void init(int opmode,
Key key,
AlgorithmParameters params,
SecureRandom random)
throws InvalidKeyException,
InvalidAlgorithmParameterException- See Also:
-
getIV, getParameters
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final void init(int opmode,
Key key,
SecureRandom random)
throws InvalidKeyException- See Also:
-
getIV, getParameters
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final void init(int opmode,
Key key,
AlgorithmParameterSpec params)
throws InvalidKeyException,
InvalidAlgorithmParameterException- See Also:
-
SecureRandomgetIV, getParameters
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final void init(int opmode,
Key key,
AlgorithmParameterSpec params,
SecureRandom random)
throws InvalidKeyException,
InvalidAlgorithmParameterException- See Also:
-
getIV, getParameters
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public static final int PRIVATE_KEY
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public static final int PUBLIC_KEY
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public static final int SECRET_KEY
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final Key unwrap(byte[] wrappedKey,
String wrappedKeyAlgorithm,
int wrappedKeyType)
throws InvalidKeyException,
NoSuchAlgorithmException- See Also:
- IllegalStateException
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public static final int UNWRAP_MODE
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final byte[] update(byte[] input)
- See Also:
- IllegalStateException
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final byte[] update(byte[] input,
int inputOffset,
int inputLen)- See Also:
- IllegalStateException
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final int update(byte[] input,
int inputOffset,
int inputLen,
byte[] output)
throws ShortBufferException- See Also:
- IllegalStateException,
getOutputSize
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final int update(byte[] input,
int inputOffset,
int inputLen,
byte[] output,
int outputOffset)
throws ShortBufferException- See Also:
- IllegalStateException,
getOutputSize
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final int update(ByteBuffer input,
ByteBuffer output)
throws ShortBufferException- See Also:
- ReadOnlyBufferException, IllegalArgumentException, IllegalStateException,
getOutputSize
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public final byte[] wrap(Key key)
throws IllegalBlockSizeException,
InvalidKeyException- See Also:
- IllegalStateException
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public static final int WRAP_MODE
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
Java API By Example, From Geeks To Geeks.