Android AES Encryption Algorithm and Its Implementation

Yesterday, the boss told me to look at Android encryption.Algorithm. So I found it online and found the AES encryption algorithm. (Of course, there are MD5 and base64 http://snowolf.iteye.com/blog/410860.)ArticleMany of them are listed, but they are basically j2se platforms and not necessarily supported by the Android platform. However, the AES algorithm Android comes with a package, which can be viewed from the official http://developer.android.com/reference/javax/crypto/cipher.html.
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What is the AES encryption algorithm? You can go to Google, expert-levelProgramThe engineer can use the package.

This example is actually from http://www.tutorials-android.com/learn/how_to_encrypt_and_decrypt_strings.rhtml.

Main file in the src directory:

Package COM. QQ; import Java. security. securerandom; import javax. crypto. cipher; import javax. crypto. keygenerator; import javax. crypto. secretkey; import javax. crypto. spec. secretkeyspec; import android. app. activity; import android. OS. bundle; import android. util. log; public class simplecrypto extends activity {public static string encrypt (string seed, string cleartext) throws exception {byte [] rawkey = getrawkey (seed. getbytes (); byte [] result = encrypt (rawkey, cleartext. getbytes (); Return tohex (result);} public static string decrypt (string seed, string encrypted) throws exception {byte [] rawkey = getrawkey (seed. getbytes (); byte [] ENC = tobyte (encrypted); byte [] result = decrypt (rawkey, ENC); return new string (result );} private Static byte [] getrawkey (byte [] seed) throws exception {keygenerator kgen = keygenerator. getinstance ("AES"); securerandom sr = securerandom. getinstance ("sha1prng"); Sr. setseed (SEED); kgen. init (128, Sr); // 192 and 256 bits may not be available secretkey skey = kgen. generatekey (); byte [] Raw = skey. getencoded (); Return raw;} Private Static byte [] encrypt (byte [] raw, byte [] Clear) throws exception {secretkeyspec skeyspec = new secretkeyspec (raw, "AES"); cipher = cipher. getinstance ("AES"); cipher. init (cipher. encrypt_mode, skeyspec); byte [] encrypted = cipher. dofinal (clear); Return encrypted;} Private Static byte [] decrypt (byte [] raw, byte [] encrypted) throws exception {secretkeyspec skeyspec = new secretkeyspec (raw, "AES"); cipher = cipher. getinstance ("AES"); cipher. init (cipher. decrypt_mode, skeyspec); byte [] decrypted = cipher. dofinal (encrypted); Return decrypted;} public static string tohex (string txt) {return tohex (txt. getbytes ();} public static string fromhex (string HEX) {return new string (tobyte (HEX);} public static byte [] tobyte (string hexstring) {int Len = hexstring. length ()/2; byte [] result = new byte [Len]; for (INT I = 0; I <Len; I ++) result [I] = integer. valueof (hexstring. substring (2 * I, 2 * I + 2), 16 ). bytevalue (); return result;} public static string tohex (byte [] BUF) {If (BUF = NULL) Return ""; stringbuffer result = new stringbuffer (2 * Buf. length); For (INT I = 0; I <Buf. length; I ++) {appendhex (result, Buf [I]);} return result. tostring ();} private final static string hex = "0123456789 abcdef"; Private Static void appendhex (stringbuffer Sb, byte B) {sb. append (hex. charat (B> 4) & 0x0f )). append (hex. charat (B & 0x0f);}/** called when the activity is first created. * // @ override public void oncreate (bundle savedinstancestate) {super. oncreate (savedinstancestate); setcontentview (R. layout. main); string masterpassword = "A"; string originaltext = "0123456789"; byte [] Text = new byte [] {'0', '1', '2 ', '3', '4', '5', '6', '7', '8', '9 '}; byte [] Password = new byte [] {'A'}; try {string encryptingcode = simplecrypto. encrypt (masterpassword, originaltext); // system. out. println ("encrypted Result:" + encryptingcode); log. I ("the encryption result is", encryptingcode); string decryptingcode = simplecrypto. decrypt (masterpassword, encryptingcode); system. out. println ("decryption Result:" + decryptingcode); log. I ("decryption result", decryptingcode);} catch (exception e) {// todo auto-generated Catch Block E. printstacktrace ();}}}

By default, the layout file main. xml and configuration file androidmanifest. XML are ready. The final result is shown in the log. Use ADB logcat> D: \ 1.txtto locate the 1.txt file on the D Drive, open it in notepad, and search for "encrypted result" to see it:

Running result (as shown in the log ):

I/the encrypted result is (190): bfb77d8f1e1ee9d5e252926a12659de8

I/Decryption result (190): 0123456789