72 lines
2.1 KiB
Java
72 lines
2.1 KiB
Java
package ru.bvn13.encryptedpreferences;
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import java.security.*;
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import javax.crypto.*;
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import javax.crypto.spec.*;
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/**
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* Created by bvn13 on 22.06.2017.
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*/
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public class EncryptionStuff
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{
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static private final String algorithm = "DES";
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static private SecureRandom sr = new SecureRandom();
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private SecretKey secretKey;
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private Cipher cipher;
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public EncryptionStuff( SecretKey secretKey ) throws GeneralSecurityException {
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this.secretKey = secretKey;
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cipher = Cipher.getInstance( algorithm );
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}
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public String arrayToString( byte raw[] ) {
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StringBuffer sb = new StringBuffer();
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for (int i=0; i<raw.length; ++i) {
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short s = (short)raw[i];
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if (s>0)
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s += 256;
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int hi = s>>4;
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int lo = s&0xf;
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sb.append( (char)('a'+hi) );
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sb.append( (char)('a'+lo) );
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}
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return sb.toString();
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}
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public byte[] stringToArray( String string ) {
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StringBuffer sb = new StringBuffer( string );
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int len = sb.length();
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if ((len&1)==1)
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throw new RuntimeException( "String must be of even length! "+string );
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byte raw[] = new byte[len/2];
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int ii=0;
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for (int i=0; i<len; i+=2) {
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int hic = sb.charAt( i ) - 'a';
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int loc = sb.charAt( i+1 ) - 'a';
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byte b = (byte)( (hic<<4) | loc );
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raw[ii++] = b;
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}
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return raw;
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}
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synchronized public String obfuscateString( String string )
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throws GeneralSecurityException {
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cipher.init( Cipher.ENCRYPT_MODE, secretKey, sr );
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byte raw[] = string.getBytes();
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byte oraw[] = cipher.doFinal( raw );
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String ostring = arrayToString( oraw );
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return ostring;
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}
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synchronized public String deObfuscateString( String string )
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throws GeneralSecurityException {
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cipher.init( Cipher.DECRYPT_MODE, secretKey, sr );
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byte raw[] = stringToArray( string );
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byte draw[] = cipher.doFinal( raw );
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String dstring = new String( draw );
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return dstring;
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}
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} |