XXX Login activity

Base64Util.java

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;

public final class Base64Util {
    private static final char[] legalChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/".toCharArray();

    public static String encode(byte[] data) {
        int d;
        int len = data.length;
        StringBuffer buf = new StringBuffer((data.length * 3) / 2);
        int end = len - 3;
        int i = 0;
        int n = 0;
        while (i <= end) {
            d = (((data[i] & 255) << 16) | ((data[i + 1] & 255) << 8)) | (data[i + 2] & 255);
            buf.append(legalChars[(d >> 18) & 63]);
            buf.append(legalChars[(d >> 12) & 63]);
            buf.append(legalChars[(d >> 6) & 63]);
            buf.append(legalChars[d & 63]);
            i += 3;
            int n2 = n + 1;
            if (n >= 14) {
                n2 = 0;
                buf.append(" ");
            }
            n = n2;
        }
        if (i == (0 + len) - 2) {
            d = ((data[i] & 255) << 16) | ((data[i + 1] & 255) << 8);
            buf.append(legalChars[(d >> 18) & 63]);
            buf.append(legalChars[(d >> 12) & 63]);
            buf.append(legalChars[(d >> 6) & 63]);
            buf.append("=");
        } else if (i == (0 + len) - 1) {
            d = (data[i] & 255) << 16;
            buf.append(legalChars[(d >> 18) & 63]);
            buf.append(legalChars[(d >> 12) & 63]);
            buf.append("==");
        }
        return buf.toString();
    }

    private static int decode(char c) {
        if (c >= 'A' && c <= 'Z') {
            return c - 65;
        }
        if (c >= 'a' && c <= 'z') {
            return (c - 97) + 26;
        }
        if (c >= '0' && c <= '9') {
            return ((c - 48) + 26) + 26;
        }
        switch (c) {
            case '+':
                return 62;
            case '/':
                return 63;
            case '=':
                return 0;
            default:
                throw new RuntimeException("unexpected code: " + c);
        }
    }

    public static byte[] decode(String s) {
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        try {
            decode(s, bos);
            byte[] decodedBytes = bos.toByteArray();
            try {
                bos.close();
            } catch (IOException ex) {
                System.err.println("Error while decoding BASE64: " + ex.toString());
            }
            return decodedBytes;
        } catch (IOException e) {
            throw new RuntimeException();
        }
    }

    private static void decode(String s, OutputStream os) throws IOException {
        int i = 0;
        int len = s.length();
        while (true) {
            if (i < len && s.charAt(i) <= ' ') {
                i++;
            } else if (i != len) {
                int tri = (((decode(s.charAt(i)) << 18) + (decode(s.charAt(i + 1)) << 12)) + (decode(s.charAt(i + 2)) << 6)) + decode(s.charAt(i + 3));
                os.write((tri >> 16) & 255);
                if (s.charAt(i + 2) != '=') {
                    os.write((tri >> 8) & 255);
                    if (s.charAt(i + 3) != '=') {
                        os.write(tri & 255);
                        i += 4;
                    } else {
                        return;
                    }
                }
                return;
            } else {
                return;
            }
        }
    }

    public static String filter(String str) {
        String output = "";
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < str.length(); i++) {
            int asc = str.charAt(i);
            if (!(asc == 10 || asc == 13)) {
                sb.append(str.subSequence(i, i + 1));
            }
        }
        return new String(sb);
    }
}

LoginGetRsaEncryptPassword.java

import java.io.ObjectInputStream;
import java.io.FileInputStream;
import java.lang.Exception;
import java.util.Date;
import javax.crypto.Cipher;
import java.security.Key;
import java.security.KeyFactory;
import java.security.spec.RSAPublicKeySpec;
import java.security.spec.PKCS8EncodedKeySpec;

class Main {
    private static String ALGORITHM = "RSA/ECB/PKCS1Padding";

    public static void main(String[] args) throws Exception {
        String source = PasswordSalt("password");
        System.out.println(encrypt(source));
    }

    public static String PasswordSalt(String password) {
        long salt = new Date().getTime();
        return "{\"password\":\"" + password + "\",\"salt\":" + salt + '}';
    }

    public static String getiOSKey(Key key) {
        return new String(Base64Util.encode(new PKCS8EncodedKeySpec(key.getEncoded()).getEncoded()));
    }

    public static void getPublicComponents() throws Exception {
        ObjectInputStream ois = new ObjectInputStream(new FileInputStream("./PublicKey"));
        Key key = (Key) ois.readObject();
        ois.close();

        KeyFactory kf = KeyFactory.getInstance("RSA");
        RSAPublicKeySpec rsaPKS = kf.getKeySpec(key, RSAPublicKeySpec.class);
        
        System.out.println(rsaPKS.getModulus().toString(16));
        System.out.println(rsaPKS.getPublicExponent());
    }

    public static String encrypt(String source) throws Exception {
        ObjectInputStream ois = new ObjectInputStream(new FileInputStream("./PublicKey"));
        Key key = (Key) ois.readObject();
        ois.close();
        Cipher cipher = Cipher.getInstance(ALGORITHM);
        cipher.init(1, key);
        return Base64Util.encode(cipher.doFinal(source.getBytes()));
    }

    public static String decrypt(String cryptograph) throws Exception {
        ObjectInputStream ois = new ObjectInputStream(new FileInputStream("./PrivateKey"));
        Key key = (Key) ois.readObject();
        ois.close();
        Cipher cipher = Cipher.getInstance(ALGORITHM);
        cipher.init(2, key);
        return new String(cipher.doFinal(Base64Util.decode(cryptograph)));
    }
}