关于AES加密（上）

最近在编写IOS加密时，出现了IOS加（解）密与java服务器加（解）密不一致的问题，在网上也查了很多的资料，网上也没有系统的方法。今天写下这篇文章做一下记录，同时给遇到问题朋友们提供参考。首先来讲述一下java中的实现，在java实现aes加密时，遇到这样一个问题，我在mac平台中调试的代码，加（解）密能够成功，但是将代码移植到Windows平台下，就失败了。始终提示InvalidKeyException，经过查询资料，在Windows中，Oracle提供的aes加密，只支持128位加密，超过128位，如192位、256位就会出错。如果想加（解）密成功，必须下载local_policy.jar与US_export_policy.jar两个jar包，替换到本地安装目录下jre下secrity的local_policy.jar与US_export_policy.jar包，可以从http://www.oracle.com/technetwork/java/javase/downloads/index.html下载哦！不废话了，贴上JAVA的aes代码吧

AES.java

import java.security.InvalidAlgorithmParameterException;import java.security.InvalidKeyException;import java.security.NoSuchAlgorithmException;import java.security.spec.InvalidKeySpecException;import javax.crypto.BadPaddingException;import javax.crypto.Cipher;import javax.crypto.IllegalBlockSizeException;import javax.crypto.NoSuchPaddingException;import javax.crypto.SecretKey;import javax.crypto.SecretKeyFactory;import javax.crypto.spec.IvParameterSpec;import javax.crypto.spec.PBEKeySpec;import javax.crypto.spec.SecretKeySpec;public class AES {private final String KEY_GENERATION_ALG = "PBKDF2WithHmacSHA1";private final int HASH_ITERATIONS = 10000;private final int KEY_LENGTH = 256;private char[] humanPassphrase = { 'P', 'e', 'r', ' ', 'v', 'a', 'l', 'l','u', 'm', ' ', 'd', 'u', 'c', 'e', 's', ' ', 'L', 'a', 'b', 'a','n', 't' };private byte[] salt = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0x0F, 0X0E, 0X0D,0X0C, 0X0B, 0X0A };private final String CIPHERMODEPADDING = "AES/CBC/PKCS5Padding";private SecretKeyFactory keyfactory = null;private SecretKey sk = null;private SecretKeySpec skforAES = null;private byte[] iv = { 0xA, 1, 0xB, 5, 4, 0xF, 7, 9, 0x17, 3, 1, 6, 8, 0xC,0xD, 91 };private IvParameterSpec IV;public AES() {try {PBEKeySpec myKeyspec = new PBEKeySpec(humanPassphrase, salt,HASH_ITERATIONS, KEY_LENGTH);keyfactory = SecretKeyFactory.getInstance(KEY_GENERATION_ALG);sk = keyfactory.generateSecret(myKeyspec);} catch (NoSuchAlgorithmException nsae) {System.out.println("no key factory support for PBEWITHSHAANDTWOFISH-CBC");} catch (InvalidKeySpecException ikse) {System.out.println("invalid key spec for PBEWITHSHAANDTWOFISH-CBC");}byte[] skAsByteArray = sk.getEncoded();skforAES = new SecretKeySpec(skAsByteArray, "AES");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;}public String decrypt(byte[] data) {String decrypted = new String(decrypt(CIPHERMODEPADDING, skforAES, IV,data));return decrypted;}/** * 加密 * @param cmp 填充方式 * @param sk 密钥 * @param IV 向量 * @param msg 需要加密的内容 * @return 返回加密结果 */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 e) {System.out.println(e.getMessage());} catch (NoSuchPaddingException e) {System.out.println(e.getMessage());} catch (InvalidKeyException e) {System.out.println(e.getMessage());} catch (InvalidAlgorithmParameterException e) {System.out.println(e.getMessage());} catch (IllegalBlockSizeException e) {System.out.println(e.getMessage());} catch (BadPaddingException e) {System.out.println(e.getMessage());}return null;}/** * 解密 * @param cmp 填充函数 * @param sk 密钥 * @param IV 向量 * @param ciphertext 需要解密内容 * @return 返回解密结果 */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) {} catch (NoSuchPaddingException nspe) {} catch (InvalidKeyException e) {System.out.println(e.getMessage());} catch (InvalidAlgorithmParameterException e) {System.out.println(e.getMessage());} catch (IllegalBlockSizeException e) {System.out.println(e.getMessage());} catch (BadPaddingException e) {System.out.println(e.getMessage());}return null;}}

Base64Decoder.java

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', '+', '/' };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 characterint x;do {x = in.read();if (x == -1) {return -1;}} while (Character.isWhitespace((char) x));charCount++;// The '=' sign is just paddingif (x == '=') {return -1; // effective end of stream}// Convert from raw form to 6-bit formx = ints[x];// Calculate which character we're decoding nowint mode = (charCount - 1) % 4;// First char save all six bits, go for anotherif (mode == 0) {carryOver = x & 63;return read();}// Second char use previous six bits and first two new bits,// save last four bitselse 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 bitselse 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 bitselse 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 optimizedint i;for (i = 0; i < len; i++) {int x = read();if (x == -1 && i == 0) { // an immediate -1 returns -1return -1;} else if (x == -1) { // a later -1 returns the chars read so farbreak;}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 */@SuppressWarnings("resource")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 bufferint bytesRead;while ((bytesRead = in.read(buf)) != -1) {out.write(buf, 0, bytesRead);}out.close();return out.toByteArray();} catch (IOException ignored) {return null;}}}

Base64Encoder.java

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 <[e-mail]>if (b < 0) {b += 256;}// First byte use first six bits, save last two bitsif (charCount % 3 == 0) {int lookup = b >> 2;carryOver = b & 3; // last two bitsout.write(chars[lookup]);}// Second byte use previous two bits and first four new bits,// save last four bitselse if (charCount % 3 == 1) {int lookup = ((carryOver << 4) + (b >> 4)) & 63;carryOver = b & 15; // last four bitsout.write(chars[lookup]);}// Third byte use previous four bits and first two new bits,// then use last six new bitselse if (charCount % 3 == 2) {int lookup = ((carryOver << 2) + (b >> 6)) & 63;out.write(chars[lookup]);lookup = b & 63; // last six bitsout.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 optimizedfor (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 bytesif (charCount % 3 == 1) { // one leftoverint lookup = (carryOver << 4) & 63;out.write(chars[lookup]);out.write('=');out.write('=');} else if (charCount % 3 == 2) { // two leftoversint 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 bufferint bytesRead;while ((bytesRead = in.read(buf)) != -1) {encoder.write(buf, 0, bytesRead);}} finally {if (in != null)in.close();if (encoder != null)encoder.close();}}}

以上就是java端的代码了，用在Android或java服务端上都可以哦。谢谢，下次贴上IOS端的代码吧！