import java.math.*;
public class RSA {
//BigDecimal
private final static BigInteger p = BigInteger.valueOf(17l);
private final static BigInteger q = BigInteger.valueOf(11l);
private BigInteger e ;
private BigInteger d = null;
private BigInteger n = null;
private BigInteger n_1=null;
RSA(long e){
this.e=BigInteger.valueOf(e);
this.birth_n();
this.birth_n_1();
this.birth_d();
}
//计算n=pq
private void birth_n(){
this.n=this.p.multiply(this.q);
}
//计算n_1=(p-1)(q-1)
private void birth_n_1(){
this.n_1=this.p.subtract(BigInteger.ONE).multiply(this.q.subtract(BigInteger.ONE));
}
//计算d
private void birth_d(){
//this.d.multiply(this.e)\
/*long i=1;
BigInteger temp=this.n_1.multiply(BigInteger.valueOf(i)).add(BigInteger.ONE);
while(temp.mod(this.e).compareTo(BigInteger.ZERO)!=0){
i++;
}
this.d=temp.divide(this.e);*/
//System.out.println(this.d);
this.d = this.e.modInverse(this.n_1);
}
//加密
public BigInteger public_rsa(long m){
return BigInteger.valueOf(m).pow(this.e.intValue()).remainder(this.n);
}
//解密
public BigInteger private_rsa(long c){
return BigInteger.valueOf(c).pow(this.d.intValue()).remainder(this.n);
}
//获取公钥
public BigInteger getE() {
return e;
}
//设置公钥
public void setE(BigInteger e) {
this.e = e;
}
//获取私钥
public BigInteger getD() {
return d;
}
public static void main(String[] args) {
RSA r = new RSA(7);
System.out.println(r.public_rsa(99));
RSA s = new RSA(3);
System.out.println(s.getD());
System.out.println(r.getD());
}
}
