高级加密标准（英语：Advanced Encryption
Standard，缩写：AES），在密码学中又称Rijndael加密法，是美国联邦政府采用的一种区块加密标准。这个标准用来替代原先的DES，已经被多方分析且广为全世界所使用。经过五年的甄选流程，高级加密标准由美国国家标准与技术研究院（NIST）于2001年11月26日发布于FIPS
PUB 197，并在2002年5月26日成为有效的标准。2006年，高级加密标准已然成为对称密钥加密中最流行的算法之一。
MD5加密算法：http://blog.csdn.net/huangxiaoguo1/article/details/78042596
Base64加密解密：http://blog.csdn.net/huangxiaoguo1/article/details/78042715
异或加密解密：http://blog.csdn.net/huangxiaoguo1/article/details/78042802
DES加密解密：http://blog.csdn.net/huangxiaoguo1/article/details/78042908
AES自动生成base64密钥加密解密：http://blog.csdn.net/huangxiaoguo1/article/details/78043000
AES加密解密（ECB模式）：http://blog.csdn.net/huangxiaoguo1/article/details/78043098
AES加密解密（CBC模式）：http://blog.csdn.net/huangxiaoguo1/article/details/78043169
非对称RSA加密解密：http://blog.csdn.net/huangxiaoguo1/article/details/78043354
密码说明
严格地说，AES和Rijndael加密法并不完全一样（虽然在实际应用中二者可以互换），因为Rijndael加密法可以支持更大范围的区块和密钥长度：AES的区块长度固定为128
比特，密钥长度则可以是128，192或256比特；而Rijndael使用的密钥和区块长度可以是32位的整数倍，以128位为下限，256比特为上限。加密过程中使用的密钥是由Rijndael密钥生成方案产生。
大多数AES计算是在一个特别的有限域完成的。
AES加密过程是在一个4×4的字节矩阵上运作，这个矩阵又称为“状态（state）”，其初值就是一个明文区块（矩阵中一个元素大小就是明文区块中的一个Byte）。（Rijndael加密法因支持更大的区块，其矩阵行数可视情况增加）加密时，各轮AES加密循环（除最后一轮外）均包含4个步骤：
AddRoundKey — 矩阵中的每一个字节都与该次轮秘钥（round key）做XOR运算；每个子密钥由密钥生成方案产生。
SubBytes — 通过非线性的替换函数，用查找表的方式把每个字节替换成对应的字节。 ShiftRows —
将矩阵中的每个横列进行循环式移位。 MixColumns — 为了充分混合矩阵中各个直行的操作。这个步骤使用线性转换来混合每列的四个字节。
最后一个加密循环中省略MixColumns步骤，而以另一个AddRoundKey取代。
加密标准
对称密码体制的发展趋势将以分组密码为重点。分组密码算法通常由密钥扩展算法和加密（解密）算法两部分组成。密钥扩展算法将b字节用户主密钥扩展成r个子密钥。加密算法由一个密码学上的弱函数f与r个子密钥迭代r次组成。混乱和密钥扩散是分组密码算法设计的基本原则。抵御已知明文的差分和线性攻击，可变长密钥和分组是该体制的设计要点。
AES是美国国家标准技术研究所NIST旨在取代DES的21世纪的加密标准。
AES的基本要求是，采用对称分组密码体制，密钥的长度最少支持为128、192、256，分组长度128位，算法应易于各种硬件和软件实现。1998年NIST开始AES第一轮分析、测试和征集，共产生了15个候选算法。1999年3月完成了第二轮AES2的分析、测试。2000年10月2日美国政府正式宣布选中比利时密码学家Joan
Daemen 和 Vincent Rijmen 提出的一种密码算法RIJNDAEL 作为 AES.
在应用方面，尽管DES在安全上是脆弱的，但由于快速DES芯片的大量生产，使得DES仍能暂时继续使用，为提高安全强度，通常使用独立密钥的三级DES。但是DES迟早要被AES代替。流密码体制较之分组密码在理论上成熟且安全，但未被列入下一代加密标准。
AES加密数据块分组长度必须为128比特，密钥长度可以是128比特、192比特、256比特中的任意一个（如果数据块及密钥长度不足时，会补齐）。AES加密有很多轮的重复和变换。大致步骤如下：1、密钥扩展（KeyExpansion），2、初始轮（Initial
Round），3、重复轮（Rounds），每一轮又包括：SubBytes、ShiftRows、MixColumns、AddRoundKey，4、最终轮（Final
Round），最终轮没有MixColumns。
效果
这里写图片描述
代码
AESCBCActivity
package tsou.com.encryption.activity.AES;
import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.text.TextUtils;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
import java.io.UnsupportedEncodingException;
import tsou.com.encryption.R;
import tsou.com.encryption.aescbc.AES;
/**
* CBC模式自设定秘钥,需要设置偏移量
* <p>
* 什么是aes加密？
* <p>
* 高级加密标准（英语：Advanced Encryption Standard，缩写：AES），
* 在密码学中又称Rijndael加密法，
* 是美国联邦政府采用的一种区块加密标准。这个标准用来替代原先的DES，
* 已经被多方分析且广为全世界所使用
*/
public class AESCBCActivity extends AppCompatActivity implements View.OnClickListener {
private EditText encryptionContext;
private Button encryption;
private TextView tvEncryption;
private Button decode;
private TextView tvDecode;
private Activity mActivity;
private Context mContext;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_aes);
mActivity = this;
mContext = this;
encryptionContext = (EditText) findViewById(R.id.et_encryption_context);
encryption = (Button) findViewById(R.id.btn_encryption);
tvEncryption = (TextView) findViewById(R.id.tv_encryption);
decode = (Button) findViewById(R.id.btn_decode);
tvDecode = (TextView) findViewById(R.id.tv_decode);
initListener();
}
private void initListener() {
encryption.setOnClickListener(this);
decode.setOnClickListener(this);
}
@Override
public void onClick(View view) {
switch (view.getId()) {
case R.id.btn_encryption://加密
String encryptionString = encryptionContext.getText().toString().trim();
if (TextUtils.isEmpty(encryptionString)) {
Toast.makeText(mContext, "请输入加密内容", Toast.LENGTH_SHORT).show();
return;
}
try {
String encrypt = AES.getInstance().encrypt(encryptionString.getBytes("UTF8"));
tvEncryption.setText(encrypt);
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
break;
case R.id.btn_decode://解密
String decodeString = tvEncryption.getText().toString().trim();
if (TextUtils.isEmpty(decodeString)) {
Toast.makeText(mContext, "请先加密", Toast.LENGTH_SHORT).show();
return;
}
String decrypt = AES.getInstance().decrypt(decodeString);
tvDecode.setText(decrypt);
break;
}
}
}
AES
package tsou.com.encryption.aescbc;
import java.io.UnsupportedEncodingException;
import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
/**
* http://blog.csdn.net/qq_33237207/article/details/53114122
*/
public class AES {
private final String CIPHERMODEPADDING = "AES/CBC/PKCS5Padding";// AES/CBC/PKCS7Padding
private SecretKeySpec skforAES = null;
private static String ivParameter = "1234huangxiaoguo";// 密钥默认偏移，可更改
private byte[] iv = ivParameter.getBytes();
private IvParameterSpec IV;
String sKey = "huangxiaoguo1234";// key必须为16位，可更改为自己的key
private static AES instance = null;
public static AES getInstance() {
if (instance == null) {
synchronized (AES.class) {
if (instance == null) {
instance = new AES();
}
}
}
return instance;
}
public AES() {
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;
}
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 (Exception nsae) {
}
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 (Exception nsae) {
}
return null;
}
}
Base64Decoder
package tsou.com.encryption.aescbc;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
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();
// }
// }
}
Base64Encoder
package tsou.com.encryption.aescbc;
import java.io.ByteArrayOutputStream;
import java.io.FilterOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
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 <chrigu@lorraine.ch>
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();
// }
// }
}
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