Admin: 1 версия

2010-06-01T05:01:30Z

1 версия

в 17:44, 31 мая 2010

2010-05-31T17:44:27Z

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== AES Key generator ==



<source lang="java">
import java.security.Key;
import java.security.Security;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
public class MainClass {
public static void main(String[] args) throws Exception {
Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
KeyGenerator generator = KeyGenerator.getInstance("AES", "BC");
generator.init(128);
Key keyToBeWrapped = generator.generateKey();
System.out.println("input : " + new String(keyToBeWrapped.getEncoded()));
Cipher cipher = Cipher.getInstance("AESWrap", "BC");
KeyGenerator KeyGen = KeyGenerator.getInstance("AES", "BC");
KeyGen.init(256);
Key wrapKey = KeyGen.generateKey();
cipher.init(Cipher.WRAP_MODE, wrapKey);
byte[] wrappedKey = cipher.wrap(keyToBeWrapped);
System.out.println("wrapped : " + new String(wrappedKey));
cipher.init(Cipher.UNWRAP_MODE, wrapKey);
Key key = cipher.unwrap(wrappedKey, "AES", Cipher.SECRET_KEY);
System.out.println("unwrapped: " + new String(key.getEncoded()));
}
}</source>



== AES wraps RSA ==



<source lang="java">
import java.security.Key;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;
import java.security.SecureRandom;
import java.security.Security;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
public class MainClass {
public static void main(String[] args) throws Exception {
Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
Cipher cipher = Cipher.getInstance("AES/ECB/PKCS7Padding", "BC");
SecureRandom random = new SecureRandom();
KeyPairGenerator fact = KeyPairGenerator.getInstance("RSA", "BC");
fact.initialize(1024, random);
KeyPair keyPair = fact.generateKeyPair();
Key wrapKey = createKeyForAES(256, random);
cipher.init(Cipher.WRAP_MODE, wrapKey);
byte[] wrappedKey = cipher.wrap(keyPair.getPrivate());
cipher.init(Cipher.UNWRAP_MODE, wrapKey);
Key key = cipher.unwrap(wrappedKey, "RSA", Cipher.PRIVATE_KEY);
System.out.println(keyPair.getPrivate().equals(key));
}
public static SecretKey createKeyForAES(int bitLength, SecureRandom random)
throws NoSuchAlgorithmException, NoSuchProviderException {
KeyGenerator generator = KeyGenerator.getInstance("AES", "BC");
generator.init(128, random);
return generator.generateKey();
}
}</source>



== Tampered message, encryption with digest, AES in CTR mode ==



<source lang="java">
import java.security.Key;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;
import java.security.SecureRandom;
import java.security.Security;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;
public class MainClass {
public static void main(String[] args) throws Exception {
Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
SecureRandom random = new SecureRandom();
IvParameterSpec ivSpec = createCtrIvForAES(1, random);
Key key = createKeyForAES(256, random);
Cipher cipher = Cipher.getInstance("AES/CTR/NoPadding", "BC");
String input = "12345678";
MessageDigest hash = MessageDigest.getInstance("SHA-1", "BC");
cipher.init(Cipher.ENCRYPT_MODE, key, ivSpec);
byte[] cipherText = new byte[cipher.getOutputSize(input.length() + hash.getDigestLength())];
int ctLength = cipher.update(input.getBytes(), 0, input.length(), cipherText, 0);
hash.update(input.getBytes());
ctLength += cipher.doFinal(hash.digest(), 0, hash.getDigestLength(), cipherText, ctLength);
cipherText[9] ^= "0" ^ "9";
cipher.init(Cipher.DECRYPT_MODE, key, ivSpec);
byte[] plainText = cipher.doFinal(cipherText, 0, ctLength);
int messageLength = plainText.length - hash.getDigestLength();
hash.update(plainText, 0, messageLength);
byte[] messageHash = new byte[hash.getDigestLength()];
System.arraycopy(plainText, messageLength, messageHash, 0, messageHash.length);
System.out.println("plain : " + new String(plainText) + " verified: "
+ MessageDigest.isEqual(hash.digest(), messageHash));
}
public static SecretKey createKeyForAES(int bitLength, SecureRandom random)
throws NoSuchAlgorithmException, NoSuchProviderException {
KeyGenerator generator = KeyGenerator.getInstance("AES", "BC");
generator.init(128, random);
return generator.generateKey();
}
public static IvParameterSpec createCtrIvForAES(int messageNumber, SecureRandom random) {
byte[] ivBytes = new byte[16];
random.nextBytes(ivBytes);
ivBytes[0] = 1;
ivBytes[1] = 2;
ivBytes[2] = 3;
ivBytes[3] = 4;
for (int i = 0; i != 7; i++) {
ivBytes[8 + i] = 0;
}
ivBytes[15] = 1;
return new IvParameterSpec(ivBytes);
}
}</source>



== Tampered message, plain encryption, AES in CTR mode ==



<source lang="java">
import java.security.Key;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;
import java.security.SecureRandom;
import java.security.Security;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;
public class MainClass {
public static void main(String[] args) throws Exception {
Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
SecureRandom random = new SecureRandom();
IvParameterSpec ivSpec = createCtrIvForAES(1, random);
Key key = createKeyForAES(256, random);
Cipher cipher = Cipher.getInstance("AES/CTR/NoPadding", "BC");
String input = "input1234567";
cipher.init(Cipher.ENCRYPT_MODE, key, ivSpec);
byte[] cipherText = cipher.doFinal(input.getBytes());
cipherText[9] ^= "0" ^ "9";
cipher.init(Cipher.DECRYPT_MODE, key, ivSpec);
byte[] plainText = cipher.doFinal(cipherText);
System.out.println("plain : " + new String(plainText));
}
public static SecretKey createKeyForAES(int bitLength, SecureRandom random)
throws NoSuchAlgorithmException, NoSuchProviderException {
KeyGenerator generator = KeyGenerator.getInstance("AES", "BC");
generator.init(128, random);
return generator.generateKey();
}
public static IvParameterSpec createCtrIvForAES(int messageNumber, SecureRandom random) {
byte[] ivBytes = new byte[16];
random.nextBytes(ivBytes);
ivBytes[0] = 1;
ivBytes[1] = 2;
ivBytes[2] = 3;
ivBytes[3] = 4;
for (int i = 0; i != 7; i++) {
ivBytes[8 + i] = 0;
}
ivBytes[15] = 1;
return new IvParameterSpec(ivBytes);
}
}</source>



== Tampered message with HMac, encryption with AES in CTR mode ==



<source lang="java">
import java.security.Key;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;
import java.security.SecureRandom;
import java.security.Security;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.Mac;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
public class MainClass {
public static void main(String[] args) throws Exception {
Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
SecureRandom random = new SecureRandom();
IvParameterSpec ivSpec = createCtrIvForAES();
Key key = createKeyForAES(256, random);
Cipher cipher = Cipher.getInstance("AES/CTR/NoPadding", "BC");
String input = "12345678";
Mac hMac = Mac.getInstance("HmacSHA1", "BC");
Key hMacKey = new SecretKeySpec(key.getEncoded(), "HmacSHA1");
System.out.println("input : " + input);
cipher.init(Cipher.ENCRYPT_MODE, key, ivSpec);
byte[] cipherText = new byte[cipher.getOutputSize(input.length() + hMac.getMacLength())];
int ctLength = cipher.update(input.getBytes(), 0, input.length(), cipherText, 0);
hMac.init(hMacKey);
hMac.update(input.getBytes());
ctLength += cipher.doFinal(hMac.doFinal(), 0, hMac.getMacLength(), cipherText, ctLength);
cipherText[9] ^= "0" ^ "9";
cipher.init(Cipher.DECRYPT_MODE, key, ivSpec);
byte[] plainText = cipher.doFinal(cipherText, 0, ctLength);
int messageLength = plainText.length - hMac.getMacLength();
hMac.init(hMacKey);
hMac.update(plainText, 0, messageLength);
byte[] messageHash = new byte[hMac.getMacLength()];
System.arraycopy(plainText, messageLength, messageHash, 0, messageHash.length);
System.out.println("plain : " + new String(plainText) + " verified: "
+ MessageDigest.isEqual(hMac.doFinal(), messageHash));
}
public static SecretKey createKeyForAES(int bitLength, SecureRandom random)
throws NoSuchAlgorithmException, NoSuchProviderException {
KeyGenerator generator = KeyGenerator.getInstance("AES", "BC");
generator.init(128, random);
return generator.generateKey();
}
public static IvParameterSpec createCtrIvForAES() {
return new IvParameterSpec("1234567812345678".getBytes());
}
}</source>



== using the KeyGenerator class and showing how to create a SecretKeySpec from an encoded key. ==



<source lang="java">
import java.security.Key;
import java.security.Security;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
public class MainClass {
public static void main(String[] args) throws Exception {
Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
byte[] input = "input".getBytes();
byte[] ivBytes = "1234567812345678".getBytes();
Cipher cipher = Cipher.getInstance("AES/CTR/NoPadding", "BC");
KeyGenerator generator = KeyGenerator.getInstance("AES", "BC");
generator.init(128);
Key encryptionKey = generator.generateKey();
System.out.println("key : " + new String(encryptionKey.getEncoded()));
cipher.init(Cipher.ENCRYPT_MODE, encryptionKey, new IvParameterSpec(ivBytes));
byte[] cipherText = new byte[cipher.getOutputSize(input.length)];
int ctLength = cipher.update(input, 0, input.length, cipherText, 0);
ctLength += cipher.doFinal(cipherText, ctLength);
Key decryptionKey = new SecretKeySpec(encryptionKey.getEncoded(), encryptionKey.getAlgorithm());
cipher.init(Cipher.DECRYPT_MODE, decryptionKey, new IvParameterSpec(ivBytes));
byte[] plainText = new byte[cipher.getOutputSize(ctLength)];
int ptLength = cipher.update(cipherText, 0, ctLength, plainText, 0);
ptLength += cipher.doFinal(plainText, ptLength);
System.out.println("plain : " + new String(plainText));
}
}</source>

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Admin: 1 версия

в 17:44, 31 мая 2010