一开始不知道有BigInteger这个大数类，居然自己去实现了一个，写了大数加法后，才发现有现成的T_T
| 以下是引用片段： package rsa; import java.math.BigInteger; public class RSA { private long p,q,e,d,n; public RSA(){ int pIndex = (int)(Math.random()*10); int qIndex; int eIndex; do{ qIndex = (int)(Math.random()*10); } while(qIndex==pIndex); do{ eIndex = (int)(Math.random()*10); } while(eIndex==pIndex||eIndex==pIndex); p = 1033; q = 2017; e = 29437; n = p*q; d = calculateD(); } private long calculateD(){ long t0 = 0,t1 = 1,t2 = -1; long r0 = (p-1)*(q-1), m = r0,r1 = e ,r2 = -1; do{ long q = r0/r1; r2 = r0-r1*q; if(r2==0)break; t2 = t0 - t1*q; while(t2<0){ t2+=m; } if(t2>=m){ t2 %= m; } r0 = r1; r1 = r2; t0 = t1; t1 = t2; }while(r2!=0); if(r1!=1){ return 0; } else{ return t2; } } public long getE() { return e; } public long getN() { return n; } public long getD() { return d; } public BigInteger encode(BigInteger data){ return pow(data,d).mod(new BigInteger(n+"")); } public BigInteger decode(BigInteger code){ return pow(code,e).mod(new BigInteger(n+"")); } public BigInteger pow(BigInteger data,long p){ data = data.pow((int)p); return data; } public static void main(String args[]){ RSA rsa = new RSA(); BigInteger data = new BigInteger("222222"); long oldtime = System.currentTimeMillis(); BigInteger code = rsa.encode(data); long newtime = System.currentTimeMillis(); double codetime = ((double)(newtime-oldtime))/1000; oldtime = System.currentTimeMillis(); BigInteger decode = rsa.decode(code); newtime = System.currentTimeMillis(); double decodetime = ((double)(newtime-oldtime))/1000; System.out.println("privateKey:"+rsa.d); System.out.println("publickKey:"+rsa.e); System.out.println("N:"+rsa.n); System.out.println("data:"+data); System.out.println("code:"+code+" time:"+codetime); System.out.println("decode:"+decode+" time:"+decodetime); } } |
