Quickly understand Android password encryption (i) _android

Nonsense not to say more, directly to everyone paste code.

Import Java.util.Random;
Import Javax.crypto.Cipher;
Import Javax.crypto.SecretKey;
Import Javax.crypto.SecretKeyFactory;
Import Javax.crypto.spec.PBEKeySpec;
Import Javax.crypto.spec.PBEParameterSpec; public class Token {* * * password-based encryption creation step * 1, read password * Convert required encrypted string to character array * Save password to Pbekeyspec Object * 2, Generate secret key by password * through Secretkeyfactory factory class G Etinstance static method to get Secretkeyfactory object; * GetInstance method requires a parameter--specify password encryption algorithm {* 1, Pbewithmd5anddes * 2, Pbewithhmacsha1anddesede} * Generate secret Key * 3 by Secretkeyfactory factory class Generatesecret () method, generate random number (salt) * Salt must be a byte array of 8 elements * Generate random numbers and assign random numbers to byte arrays using the Nextbyte method of the random class, the parameter is byte array * 4, create and initialize the cipher * The Cipher object is obtained by the GetInstance method, and the parameter is a password based encryption algorithm * The cipher object is specified by the Pbeparameterspec class constructor based on password-encrypted algorithm (including salt to improve crack difficulty) * 5, get plaintext, encrypt * Execute cipher dofinal () method for encrypting, the result of encryption is saved in byte array ctext * * */ /password encryption operation method public byte[] Cmdencryptionoperation (String encryptionstr,string pwdstr) throws Exception {//Read password//
Converts a password to a character array char[] pwd = Pwdstr.tochararray ();
Stores the encrypted array to the Pbekeyspec object Pbekeyspec pbekeyspec = new Pbekeyspec (PWD); Generate secret key by Password//via SecretkeyfactoryThe GetInstance method creates a Secretkeyfactory object, which is constructed with an encryption type secretkeyfactory secretkeyfactory = secretkeyfactory. GetInstance ("
Pbewithmd5anddes ");//Throw no keyword exception found//Generate password via Generatesecret secretkey key = Secretkeyfactory.generatesecret (PBEKEYSPEC);
Generate random number (salt)//Create a 8 element of the byte array of salt byte[] salt = new byte[8];
The random number is generated by the Nextbyte method of the Random class and the random number is assigned to the byte array, and the parameter is a byte array Random Random = new Random ();
Random.nextbytes (salt);
Create and initialize the cipher Cipher Cipher = cipher.getinstance ("Pbewithmd5anddes");
Pbeparameterspec Parameterspec = new Pbeparameterspec (salt, 1000);
Cipher.init (Cipher.encrypt_mode, Key,parameterspec);
Get plaintext, encrypt byte[] Ptext = encryptionstr.getbytes ("UTF-8");
byte[] Ctext = cipher.dofinal (ptext)//cipher dofinal method to encrypt return ctext; }
}

Use encryption Method:

public static void Main (string[] args) throws Exception {
Token Token = new Token ();
byte[] Ctext = token.cmdencryptionoperation ("Add QQ group 499092562 Exchanges!!") "," 2016/4/5 ");
FileOutputStream OS = new FileOutputStream ("PBEEnc.dat");
Os.write (ctext);
for (int i = 0; i < ctext.length i++) {
System.out.print (ctext[i]);
}

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