Android AES加密解密
AES加密算法模式有四种：ECB、CBC、CFB、OFB
要想AES加密，至少需要一个16位的密钥，如果是非ECB模式的加密，至少还得需要密钥偏移量。
下面是AES在线加密解密链接：
AES在线加密解密链接
如上图所示：“hello everyone!”被加密成了“X/T+Vxr5QZEp/GBr/iul8w==”
好的，那如何用android代码实现这样的加密呢？网上代码不少，但是有的确是很混乱，我现在来整理整理
主要代码如下：
AES.java类：
public class AES {
private final String KEY_GENERATION_ALG = "PBEWITHSHAANDTWOFISH-CBC";
// private final String KEY_GENERATION_ALG = "PBKDF2WithHmacSHA1";
private final int HASH_ITERATIONS = 10000;
private final int KEY_LENGTH = 128;
private char[] humanPassphrase = { 'P', 'e', 'r', ' ', 'v', 'a', 'l', 'l',
'u', 'm', ' ', 'd', 'u', 'c', 'e', 's', ' ', 'L', 'a', 'b', 'a',
'n', 't' };// per vallum duces labant
private byte[] salt = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0xA, 0xB, 0xC, 0xD,
0xE, 0xF }; // must save this for next time we want the key
private PBEKeySpec myKeyspec = new PBEKeySpec(humanPassphrase, salt,
HASH_ITERATIONS, KEY_LENGTH);
private final String CIPHERMODEPADDING = "AES/CBC/PKCS5Padding";// AES/CBC/PKCS7Padding
private SecretKeyFactory keyfactory = null;
private SecretKey sk = null;
private SecretKeySpec skforAES = null;
private static String ivParameter = "1234567890123456";// 密钥默认偏移，可更改
// private byte[] iv = { 0xA, 1, 0xB, 5, 4, 0xF, 7, 9, 0x17, 3, 1, 6, 8,
// 0xC,
// 0xD, 91 };
private byte[] iv = ivParameter.getBytes();
private IvParameterSpec IV;
String sKey = "1234567890123456";// key必须为16位，可更改为自己的key
public AES() {
try {
keyfactory = SecretKeyFactory.getInstance(KEY_GENERATION_ALG);
sk = keyfactory.generateSecret(myKeyspec);
} catch (NoSuchAlgorithmException nsae) {
Log.e("AESdemo",
"no key factory support for PBEWITHSHAANDTWOFISH-CBC");
} catch (InvalidKeySpecException ikse) {
Log.e("AESdemo", "invalid key spec for PBEWITHSHAANDTWOFISH-CBC");
}
// This is our secret key. We could just save this to a file instead of
// regenerating it
// each time it is needed. But that file cannot be on the device (too
// insecure). It could
// be secure if we kept it on a server accessible through https.
// byte[] skAsByteArray = sk.getEncoded();
byte[] skAsByteArray;
try {
skAsByteArray = sKey.getBytes("ASCII");
skforAES = new SecretKeySpec(skAsByteArray, "AES");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
IV = new IvParameterSpec(iv);
}
public String encrypt(byte[] plaintext) {
byte[] ciphertext = encrypt(CIPHERMODEPADDING, skforAES, IV, plaintext);
String base64_ciphertext = Base64Encoder.encode(ciphertext);
return base64_ciphertext;
}
public String decrypt(String ciphertext_base64) {
byte[] s = Base64Decoder.decodeToBytes(ciphertext_base64);
String decrypted = new String(decrypt(CIPHERMODEPADDING, skforAES, IV,
s));
return decrypted;
}
// Use this method if you want to add the padding manually
// AES deals with messages in blocks of 16 bytes.
// This method looks at the length of the message, and adds bytes at the end
// so that the entire message is a multiple of 16 bytes.
// the padding is a series of bytes, each set to the total bytes added (a
// number in range 1..16).
private byte[] addPadding(byte[] plain) {
byte plainpad[] = null;
int shortage = 16 - (plain.length % 16);
// if already an exact multiple of 16, need to add another block of 16
// bytes
if (shortage == 0)
shortage = 16;
// reallocate array bigger to be exact multiple, adding shortage bits.
plainpad = new byte[plain.length + shortage];
for (int i = 0; i < plain.length; i++) {
plainpad[i] = plain[i];
}
for (int i = plain.length; i < plain.length + shortage; i++) {
plainpad[i] = (byte) shortage;
}
return plainpad;
}
// Use this method if you want to remove the padding manually
// This method removes the padding bytes
private byte[] dropPadding(byte[] plainpad) {
byte plain[] = null;
int drop = plainpad[plainpad.length - 1]; // last byte gives number of
// bytes to drop
// reallocate array smaller, dropping the pad bytes.
plain = new byte[plainpad.length - drop];
for (int i = 0; i < plain.length; i++) {
plain[i] = plainpad[i];
plainpad[i] = 0; // don't keep a copy of the decrypt
}
return plain;
}
private byte[] encrypt(String cmp, SecretKey sk, IvParameterSpec IV,
byte[] msg) {
try {
Cipher c = Cipher.getInstance(cmp);
c.init(Cipher.ENCRYPT_MODE, sk, IV);
return c.doFinal(msg);
} catch (NoSuchAlgorithmException nsae) {
Log.e("AESdemo", "no cipher getinstance support for " + cmp);
} catch (NoSuchPaddingException nspe) {
Log.e("AESdemo", "no cipher getinstance support for padding " + cmp);
} catch (InvalidKeyException e) {
Log.e("AESdemo", "invalid key exception");
} catch (InvalidAlgorithmParameterException e) {
Log.e("AESdemo", "invalid algorithm parameter exception");
} catch (IllegalBlockSizeException e) {
Log.e("AESdemo", "illegal block size exception");
} catch (BadPaddingException e) {
Log.e("AESdemo", "bad padding exception");
}
return null;
}
private byte[] decrypt(String cmp, SecretKey sk, IvParameterSpec IV,
byte[] ciphertext) {
try {
Cipher c = Cipher.getInstance(cmp);
c.init(Cipher.DECRYPT_MODE, sk, IV);
return c.doFinal(ciphertext);
} catch (NoSuchAlgorithmException nsae) {
Log.e("AESdemo", "no cipher getinstance support for " + cmp);
} catch (NoSuchPaddingException nspe) {
Log.e("AESdemo", "no cipher getinstance support for padding " + cmp);
} catch (InvalidKeyException e) {
Log.e("AESdemo", "invalid key exception");
} catch (InvalidAlgorithmParameterException e) {
Log.e("AESdemo", "invalid algorithm parameter exception");
} catch (IllegalBlockSizeException e) {
Log.e("AESdemo", "illegal block size exception");
} catch (BadPaddingException e) {
Log.e("AESdemo", "bad padding exception");
e.printStackTrace();
}
return null;
}
}
package com.test.aesforandroid;
import java.io.*;
public class Base64Decoder extends FilterInputStream {
private static final char[] chars = { 'A', 'B', 'C', 'D', 'E', 'F', 'G',
'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T',
'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g',
'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't',
'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6',
'7', '8', '9', '+', '/' };
// A mapping between char values and six-bit integers
private static final int[] ints = new int[128];
static {
for (int i = 0; i < 64; i++) {
ints[chars[i]] = i;
}
}
private int charCount;
private int carryOver;
/***
* Constructs a new Base64 decoder that reads input from the given
* InputStream.
*
* @param in
* the input stream
*/
public Base64Decoder(InputStream in) {
super(in);
}
/***
* Returns the next decoded character from the stream, or -1 if end of
* stream was reached.
*
* @return the decoded character, or -1 if the end of the input stream is
* reached
* @exception IOException
* if an I/O error occurs
*/
public int read() throws IOException {
// Read the next non-whitespace character
int x;
do {
x = in.read();
if (x == -1) {
return -1;
}
} while (Character.isWhitespace((char) x));
charCount++;
// The '=' sign is just padding
if (x == '=') {
return -1; // effective end of stream
}
// Convert from raw form to 6-bit form
x = ints[x];
// Calculate which character we're decoding now
int mode = (charCount - 1) % 4;
// First char save all six bits, go for another
if (mode == 0) {
carryOver = x & 63;
return read();
}
// Second char use previous six bits and first two new bits,
// save last four bits
else if (mode == 1) {
int decoded = ((carryOver << 2) + (x >> 4)) & 255;
carryOver = x & 15;
return decoded;
}
// Third char use previous four bits and first four new bits,
// save last two bits
else if (mode == 2) {
int decoded = ((carryOver << 4) + (x >> 2)) & 255;
carryOver = x & 3;
return decoded;
}
// Fourth char use previous two bits and all six new bits
else if (mode == 3) {
int decoded = ((carryOver << 6) + x) & 255;
return decoded;
}
return -1; // can't actually reach this line
}
/***
* Reads decoded data into an array of bytes and returns the actual number
* of bytes read, or -1 if end of stream was reached.
*
* @param buf
* the buffer into which the data is read
* @param off
* the start offset of the data
* @param len
* the maximum number of bytes to read
* @return the actual number of bytes read, or -1 if the end of the input
* stream is reached
* @exception IOException
* if an I/O error occurs
*/
public int read(byte[] buf, int off, int len) throws IOException {
if (buf.length < (len + off - 1)) {
throw new IOException("The input buffer is too small: " + len
+ " bytes requested starting at offset " + off
+ " while the buffer " + " is only " + buf.length
+ " bytes long.");
}
// This could of course be optimized
int i;
for (i = 0; i < len; i++) {
int x = read();
if (x == -1 && i == 0) { // an immediate -1 returns -1
return -1;
} else if (x == -1) { // a later -1 returns the chars read so far
break;
}
buf[off + i] = (byte) x;
}
return i;
}
/***
* Returns the decoded form of the given encoded string, as a String. Note
* that not all binary data can be represented as a String, so this method
* should only be used for encoded String data. Use decodeToBytes()
* otherwise.
*
* @param encoded
* the string to decode
* @return the decoded form of the encoded string
*/
public static String decode(String encoded) {
return new String(decodeToBytes(encoded));
}
/***
* Returns the decoded form of the given encoded string, as bytes.
*
* @param encoded
* the string to decode
* @return the decoded form of the encoded string
*/
public static byte[] decodeToBytes(String encoded) {
byte[] bytes = null;
try {
bytes = encoded.getBytes("UTF-8");
} catch (UnsupportedEncodingException ignored) {
}
Base64Decoder in = new Base64Decoder(new ByteArrayInputStream(bytes));
ByteArrayOutputStream out = new ByteArrayOutputStream(
(int) (bytes.length * 0.67));
try {
byte[] buf = new byte[4 * 1024]; // 4K buffer
int bytesRead;
while ((bytesRead = in.read(buf)) != -1) {
out.write(buf, 0, bytesRead);
}
out.close();
return out.toByteArray();
} catch (IOException ignored) {
return null;
}
}
public static void main(String[] args) throws Exception {
if (args.length != 1) {
System.err.println("Usage: java Base64Decoder fileToDecode");
return;
}
Base64Decoder decoder = null;
try {
decoder = new Base64Decoder(new BufferedInputStream(
new FileInputStream(args[0])));
byte[] buf = new byte[4 * 1024]; // 4K buffer
int bytesRead;
while ((bytesRead = decoder.read(buf)) != -1) {
System.out.write(buf, 0, bytesRead);
}
} finally {
if (decoder != null)
decoder.close();
}
}
}
package com.test.aesforandroid;
import java.io.*;
public class Base64Encoder extends FilterOutputStream {
private static final char[] chars = { 'A', 'B', 'C', 'D', 'E', 'F', 'G',
'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T',
'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g',
'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't',
'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6',
'7', '8', '9', '+', '/' };
private int charCount;
private int carryOver;
/***
* Constructs a new Base64 encoder that writes output to the given
* OutputStream.
*
* @param out
* the output stream
*/
public Base64Encoder(OutputStream out) {
super(out);
}
/***
* Writes the given byte to the output stream in an encoded form.
*
* @exception IOException
* if an I/O error occurs
*/
public void write(int b) throws IOException {
// Take 24-bits from three octets, translate into four encoded chars
// Break lines at 76 chars
// If necessary, pad with 0 bits on the right at the end
// Use = signs as padding at the end to ensure encodedLength % 4 == 0
// Remove the sign bit,
// thanks to Christian Schweingruber
if (b < 0) {
b += 256;
}
// First byte use first six bits, save last two bits
if (charCount % 3 == 0) {
int lookup = b >> 2;
carryOver = b & 3; // last two bits
out.write(chars[lookup]);
}
// Second byte use previous two bits and first four new bits,
// save last four bits
else if (charCount % 3 == 1) {
int lookup = ((carryOver << 4) + (b >> 4)) & 63;
carryOver = b & 15; // last four bits
out.write(chars[lookup]);
}
// Third byte use previous four bits and first two new bits,
// then use last six new bits
else if (charCount % 3 == 2) {
int lookup = ((carryOver << 2) + (b >> 6)) & 63;
out.write(chars[lookup]);
lookup = b & 63; // last six bits
out.write(chars[lookup]);
carryOver = 0;
}
charCount++;
// Add newline every 76 output chars (that's 57 input chars)
if (charCount % 57 == 0) {
out.write('\n');
}
}
/***
* Writes the given byte array to the output stream in an encoded form.
*
* @param buf
* the data to be written
* @param off
* the start offset of the data
* @param len
* the length of the data
* @exception IOException
* if an I/O error occurs
*/
public void write(byte[] buf, int off, int len) throws IOException {
// This could of course be optimized
for (int i = 0; i < len; i++) {
write(buf[off + i]);
}
}
/***
* Closes the stream, this MUST be called to ensure proper padding is
* written to the end of the output stream.
*
* @exception IOException
* if an I/O error occurs
*/
public void close() throws IOException {
// Handle leftover bytes
if (charCount % 3 == 1) { // one leftover
int lookup = (carryOver << 4) & 63;
out.write(chars[lookup]);
out.write('=');
out.write('=');
} else if (charCount % 3 == 2) { // two leftovers
int lookup = (carryOver << 2) & 63;
out.write(chars[lookup]);
out.write('=');
}
super.close();
}
/***
* Returns the encoded form of the given unencoded string. The encoder uses
* the ISO-8859-1 (Latin-1) encoding to convert the string to bytes. For
* greater control over the encoding, encode the string to bytes yourself
* and use encode(byte[]).
*
* @param unencoded
* the string to encode
* @return the encoded form of the unencoded string
*/
public static String encode(String unencoded) {
byte[] bytes = null;
try {
bytes = unencoded.getBytes("UTF-8");
} catch (UnsupportedEncodingException ignored) {
}
return encode(bytes);
}
/***
* Returns the encoded form of the given unencoded string.
*
* @param bytes
* the bytes to encode
* @return the encoded form of the unencoded string
*/
public static String encode(byte[] bytes) {
ByteArrayOutputStream out = new ByteArrayOutputStream(
(int) (bytes.length * 1.37));
Base64Encoder encodedOut = new Base64Encoder(out);
try {
encodedOut.write(bytes);
encodedOut.close();
return out.toString("UTF-8");
} catch (IOException ignored) {
return null;
}
}
public static void main(String[] args) throws Exception {
if (args.length != 1) {
System.err
.println("Usage: java com.oreilly.servlet.Base64Encoder fileToEncode");
return;
}
Base64Encoder encoder = null;
BufferedInputStream in = null;
try {
encoder = new Base64Encoder(System.out);
in = new BufferedInputStream(new FileInputStream(args[0]));
byte[] buf = new byte[4 * 1024]; // 4K buffer
int bytesRead;
while ((bytesRead = in.read(buf)) != -1) {
encoder.write(buf, 0, bytesRead);
}
} finally {
if (in != null)
in.close();
if (encoder != null)
encoder.close();
}
}
}
package com.test.aesforandroid;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.widget.TextView;
public class MainActivity extends Activity {
private TextView textView1, textView2;
String mString = "hello everyone!";
byte[] mBytes = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
textView1 = (TextView) findViewById(R.id.textView1);
textView2 = (TextView) findViewById(R.id.textView2);
AES mAes = new AES();
try {
mBytes = mString.getBytes("UTF8");
} catch (Exception e) {
Log.i("qing", "MainActivity----catch");
}
String enString = mAes.encrypt(mBytes);
textView1.setText("加密后：" + enString);
String deString = mAes.decrypt(enString);
textView2.setText("解密后：" + deString);
}
}
与上面在线测试工具的相比对，一模一样，棒棒哒，搞定！
附上我上传到CSDN上的代码：http://download.csdn.net/detail/qq_33237207/9678602