有人可以帮我解决Github中我想用于项目的代码吗 我是Android编程的新手，也是加密的新手。
为什么我在解密代码时遇到错误？这样做的正确方法是什么？
import android.app.*;
import android.os.*;
import android.view.*;
import android.widget.*;
import javax.crypto.*;
import android.util.*;
public class MainActivity extends Activity
{
MCrypt mc;
TextView tv1;
TextView tv2;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
tv1 = (TextView) findViewById(R.id.textView1);
tv2 = (TextView) findViewById(R.id.textView2);
byte[] salt = MCrypt.generateSalt();
SecretKey sk = MCrypt.deriveKeyPkcs12(salt, "password");
String tvText = MCrypt.encryptPkcs12("text",sk,salt);
tv1.setText(tvText);
String tvText2 = MCrypt.decryptPkcs12(tvText,"password");
tv2.setText(tvText2);
}
}
我从Github复制的课程如下。我只想使用PKCS12方法加密/解密
import java.io.UnsupportedEncodingException;
import java.security.GeneralSecurityException;
import java.security.Provider;
import java.security.Provider.Service;
import java.security.SecureRandom;
import java.security.Security;
import java.security.spec.KeySpec;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.PBEParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import android.util.Base64;
import android.util.Log;
public class Crypto {
private static final String TAG = Crypto.class.getSimpleName();
public static final String PKCS12_DERIVATION_ALGORITHM = "PBEWITHSHA256AND256BITAES-CBC-BC";
public static final String PBKDF2_DERIVATION_ALGORITHM = "PBKDF2WithHmacSHA1";
private static final String CIPHER_ALGORITHM = "AES/CBC/PKCS5Padding";
private static String DELIMITER = "]";
private static int KEY_LENGTH = 256;
// minimum values recommended by PKCS#5, increase as necessary
private static int ITERATION_COUNT = 1000;
private static final int PKCS5_SALT_LENGTH = 8;
private static SecureRandom random = new SecureRandom();
private Crypto() {
}
public static void listAlgorithms(String algFilter) {
Provider[] providers = Security.getProviders();
for (Provider p : providers) {
String providerStr = String.format("%s/%s/%f\n", p.getName(),
p.getInfo(), p.getVersion());
Log.d(TAG, providerStr);
Set<Service> services = p.getServices();
List<String> algs = new ArrayList<String>();
for (Service s : services) {
boolean match = true;
if (algFilter != null) {
match = s.getAlgorithm().toLowerCase()
.contains(algFilter.toLowerCase());
}
if (match) {
String algStr = String.format("\t%s/%s/%s", s.getType(),
s.getAlgorithm(), s.getClassName());
algs.add(algStr);
}
}
Collections.sort(algs);
for (String alg : algs) {
Log.d(TAG, "\t" + alg);
}
Log.d(TAG, "");
}
}
// Illustration code only: don't use in production!
public static SecretKey deriveKeyPad(String password) {
try {
long start = System.currentTimeMillis();
byte[] keyBytes = new byte[KEY_LENGTH / 8];
// explicitly fill with zeros
Arrays.fill(keyBytes, (byte) 0x0);
// if password is shorter then key length, it will be zero-padded
// to key length
byte[] passwordBytes = password.getBytes("UTF-8");
int length = passwordBytes.length < keyBytes.length ? PasswordBytes.length
: keyBytes.length;
System.arraycopy(passwordBytes, 0, keyBytes, 0, length);
SecretKey result = new SecretKeySpec(keyBytes, "AES");
long elapsed = System.currentTimeMillis() - start;
Log.d(TAG, String.format("Padding key derivation took %d [ms].",
elapsed));
return result;
} catch (UnsupportedEncodingException e) {
throw new RuntimeException(e);
}
}
// Illustration code only: don't use in production!
public static SecretKey deriveKeySha1prng(String password) {
try {
long start = System.currentTimeMillis();
KeyGenerator kgen = KeyGenerator.getInstance("AES");
SecureRandom sr = SecureRandom.getInstance("SHA1PRNG");
byte[] seed = password.getBytes("UTF-8");
sr.setSeed(seed);
kgen.init(KEY_LENGTH, sr);
SecretKey result = kgen.generateKey();
long elapsed = System.currentTimeMillis() - start;
Log.d(TAG, String.format("SHA1PRNG key derivation took %d [ms].",
elapsed));
return result;
} catch (GeneralSecurityException e) {
throw new RuntimeException(e);
} catch (UnsupportedEncodingException e) {
throw new RuntimeException(e);
}
}
public static SecretKey deriveKeyPkcs12(byte[] salt, String password) {
try {
long start = System.currentTimeMillis();
KeySpec keySpec = new PBEKeySpec(password.toCharArray(), salt,
ITERATION_COUNT, KEY_LENGTH);
SecretKeyFactory keyFactory = SecretKeyFactory
.getInstance(PKCS12_DERIVATION_ALGORITHM);
SecretKey result = keyFactory.generateSecret(keySpec);
long elapsed = System.currentTimeMillis() - start;
Log.d(TAG, String.format("PKCS#12 key derivation took %d [ms].",
elapsed));
return result;
} catch (GeneralSecurityException e) {
throw new RuntimeException(e);
}
}
public static SecretKey deriveKeyPbkdf2(byte[] salt, String password) {
try {
long start = System.currentTimeMillis();
KeySpec keySpec = new PBEKeySpec(password.toCharArray(), salt,
ITERATION_COUNT, KEY_LENGTH);
SecretKeyFactory keyFactory = SecretKeyFactory
.getInstance(PBKDF2_DERIVATION_ALGORITHM);
byte[] keyBytes = keyFactory.generateSecret(keySpec).getEncoded();
Log.d(TAG, "key bytes: " + toHex(keyBytes));
SecretKey result = new SecretKeySpec(keyBytes, "AES");
long elapsed = System.currentTimeMillis() - start;
Log.d(TAG, String.format("PBKDF2 key derivation took %d [ms].",
elapsed));
return result;
} catch (GeneralSecurityException e) {
throw new RuntimeException(e);
}
}
public static byte[] generateIv(int length) {
byte[] b = new byte[length];
random.nextBytes(b);
return b;
}
public static byte[] generateSalt() {
byte[] b = new byte[PKCS5_SALT_LENGTH];
random.nextBytes(b);
return b;
}
public static String encryptPkcs12(String plaintext, SecretKey key,
byte[] salt) {
try {
Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);
PBEParameterSpec pbeSpec = new PBEParameterSpec(salt,
ITERATION_COUNT);
cipher.init(Cipher.ENCRYPT_MODE, key, pbeSpec);
Log.d(TAG, "Cipher IV: " + toHex(cipher.getIV()));
byte[] cipherText = cipher.doFinal(plaintext.getBytes("UTF-8"));
return String.format("%s%s%s", toBase64(salt), DELIMITER,
toBase64(cipherText));
} catch (GeneralSecurityException e) {
throw new RuntimeException(e);
} catch (UnsupportedEncodingException e) {
throw new RuntimeException(e);
}
}
public static String encrypt(String plaintext, SecretKey key, byte[] salt) {
try {
Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);
byte[] iv = generateIv(cipher.getBlockSize());
Log.d(TAG, "IV: " + toHex(iv));
IvParameterSpec ivParams = new IvParameterSpec(iv);
cipher.init(Cipher.ENCRYPT_MODE, key, ivParams);
Log.d(TAG, "Cipher IV: "
+ (cipher.getIV() == null ? Null : toHex(cipher.getIV())));
byte[] cipherText = cipher.doFinal(plaintext.getBytes("UTF-8"));
if (salt != null) {
return String.format("%s%s%s%s%s", toBase64(salt), DELIMITER,
toBase64(iv), DELIMITER, toBase64(cipherText));
}
return String.format("%s%s%s", toBase64(iv), DELIMITER,
toBase64(cipherText));
} catch (GeneralSecurityException e) {
throw new RuntimeException(e);
} catch (UnsupportedEncodingException e) {
throw new RuntimeException(e);
}
}
public static String toHex(byte[] bytes) {
StringBuffer buff = new StringBuffer();
for (byte b : bytes) {
buff.append(String.format("%02X", b));
}
return buff.toString();
}
public static String toBase64(byte[] bytes) {
return Base64.encodeToString(bytes, Base64.NO_WRAP);
}
public static byte[] fromBase64(String base64) {
return Base64.decode(base64, Base64.NO_WRAP);
}
public static String decryptPkcs12(byte[] cipherBytes, SecretKey key,
byte[] salt) {
try {
Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);
PBEParameterSpec pbeSpec = new PBEParameterSpec(salt,
ITERATION_COUNT);
cipher.init(Cipher.DECRYPT_MODE, key, pbeSpec);
Log.d(TAG, "Cipher IV: " + toHex(cipher.getIV()));
byte[] plainBytes = cipher.doFinal(cipherBytes);
String plainrStr = new String(plainBytes, "UTF-8");
return plainrStr;
} catch (GeneralSecurityException e) {
throw new RuntimeException(e);
} catch (UnsupportedEncodingException e) {
throw new RuntimeException(e);
}
}
public static String decrypt(byte[] cipherBytes, SecretKey key, byte[] iv) {
try {
Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);
IvParameterSpec ivParams = new IvParameterSpec(iv);
cipher.init(Cipher.DECRYPT_MODE, key, ivParams);
Log.d(TAG, "Cipher IV: " + toHex(cipher.getIV()));
byte[] plaintext = cipher.doFinal(cipherBytes);
String plainrStr = new String(plaintext, "UTF-8");
return plainrStr;
} catch (GeneralSecurityException e) {
throw new RuntimeException(e);
} catch (UnsupportedEncodingException e) {
throw new RuntimeException(e);
}
}
public static String decryptPkcs12(String ciphertext, String password) {
String[] fields = ciphertext.split(DELIMITER);
if (fields.length != 2) {
throw new IllegalArgumentException("Invalid encypted text format");
}
byte[] salt = fromBase64(fields[0]);
byte[] cipherBytes = fromBase64(fields[1]);
SecretKey key = deriveKeyPkcs12(salt, password);
return decryptPkcs12(cipherBytes, key, salt);
}
public static String decryptPbkdf2(String ciphertext, String password) {
String[] fields = ciphertext.split(DELIMITER);
if (fields.length != 3) {
throw new IllegalArgumentException("Invalid encypted text format");
}
byte[] salt = fromBase64(fields[0]);
byte[] iv = fromBase64(fields[1]);
byte[] cipherBytes = fromBase64(fields[2]);
SecretKey key = deriveKeyPbkdf2(salt, password);
return decrypt(cipherBytes, key, iv);
}
public static String decryptNoSalt(String ciphertext, SecretKey key) {
String[] fields = ciphertext.split(DELIMITER);
if (fields.length != 2) {
throw new IllegalArgumentException("Invalid encypted text format");
}
byte[] iv = fromBase64(fields[0]);
byte[] cipherBytes = fromBase64(fields[1]);
return decrypt(cipherBytes, key, iv);
}
}
logcat位于
之下FATAL EXCEPTION: main
10-06 19:16:46.236 3945 3945 E AndroidRuntime com.mycompany.myapp Process: com.mycompany.myapp, PID: 3945
10-06 19:16:46.236 3945 3945 E AndroidRuntime com.mycompany.myapp java.lang.RuntimeException: Unable to start activity ComponentInfo{com.mycompany.myapp/com.mycompany.myapp.MainActivity}: java.lang.RuntimeException: javax.crypto.BadPaddingException: error:06065064:digital envelope routines:EVP_DecryptFinal_ex:bad decrypt
10-06 19:16:46.236 3945 3945 E AndroidRuntime com.mycompany.myapp at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2205)
10-06 19:16:46.236 3945 3945 E AndroidRuntime com.mycompany.myapp at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2255)
10-06 19:16:46.236 3945 3945 E AndroidRuntime com.mycompany.myapp at android.app.ActivityThread.access$800(ActivityThread.java:142)
10-06 19:16:46.236 3945 3945 E AndroidRuntime com.mycompany.myapp at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1203)
10-06 19:16:46.236 3945 3945 E AndroidRuntime com.mycompany.myapp at android.os.Handler.dispatchMessage(Handler.java:102)
10-06 19:16:46.236 3945 3945 E AndroidRuntime com.mycompany.myapp at android.os.Looper.loop(Looper.java:136)
10-06 19:16:46.236 3945 3945 E AndroidRuntime com.mycompany.myapp at android.app.ActivityThread.main(ActivityThread.java:5118)
10-06 19:16:46.236 3945 3945 E AndroidRuntime com.mycompany.myapp at java.lang.reflect.Method.invoke(Native Method)
10-06 19:16:46.236 3945 3945 E AndroidRuntime com.mycompany.myapp at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:794)
10-06 19:16:46.236 3945 3945 E AndroidRuntime com.mycompany.myapp at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:610)
10-06 19:16:46.236 3945 3945 E AndroidRuntime com.mycompany.myapp Caused by: java.lang.RuntimeException: javax.crypto.BadPaddingException: error:06065064:digital envelope routines:EVP_DecryptFinal_ex:bad decrypt
10-06 19:16:46.236 3945 3945 E AndroidRuntime com.mycompany.myapp at com.mycompany.myapp.MCrypt.decryptPkcs12(MCrypt.java:256)
10-06 19:16:46.236 3945 3945 E AndroidRuntime com.mycompany.myapp at com.mycompany.myapp.MCrypt.decryptPkcs12(MCrypt.java:289)
10-06 19:16:46.236 3945 3945 E AndroidRuntime com.mycompany.myapp at com.mycompany.myapp.MainActivity.onCreate(MainActivity.java:33)
10-06 19:16:46.236 3945 3945 E AndroidRuntime com.mycompany.myapp at android.app.Activity.performCreate(Activity.java:5275)
10-06 19:16:46.236 3945 3945 E AndroidRuntime com.mycompany.myapp at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
10-06 19:16:46.236 3945 3945 E AndroidRuntime com.mycompany.myapp at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2169)
10-06 19:16:46.236 3945 3945 E AndroidRuntime com.mycompany.myapp ... 9 more
10-06 19:16:46.236 3945 3945 E AndroidRuntime com.mycompany.myapp Caused by: javax.crypto.BadPaddingException: error:06065064:digital envelope routines:EVP_DecryptFinal_ex:bad decrypt
10-06 19:16:46.236 3945 3945 E AndroidRuntime com.mycompany.myapp at com.android.org.conscrypt.NativeCrypto.EVP_CipherFinal_ex(Native Method)
10-06 19:16:46.236 3945 3945 E AndroidRuntime com.mycompany.myapp at com.android.org.conscrypt.OpenSSLCipher.doFinalInternal(OpenSSLCipher.java:420)
10-06 19:16:46.236 3945 3945 E AndroidRuntime com.mycompany.myapp at com.android.org.conscrypt.OpenSSLCipher.engineDoFinal(OpenSSLCipher.java:456)
10-06 19:16:46.236 3945 3945 E AndroidRuntime com.mycompany.myapp at javax.crypto.Cipher.doFinal(Cipher.java:1204)
10-06 19:16:46.236 3945 3945 E AndroidRuntime com.mycompany.myapp at com.mycompany.myapp.MCrypt.decryptPkcs12(MCrypt.java:251)
答案 0 :(得分：0)
您有一个UnsupportedEncodingException。我怀疑这是因为您正在尝试将加密的密文分配给字符串。如果要将Cyphertext视为字符串，则应将其视为字节数据或使用Base64进行编码。您需要检查MCrypt.encryptPkcs12()方法给您的回报类型。
如果您使用Base64，请务必在解密之前将其从Base64字符串转换回字节。