RSA算法C语言代码

#includestdlib.h#includestdio.h#includestring.h#includemath.h#includetime.hchars[100],*c;intn,e,d,i,C,j,k=0,len;intstr[100],b[30];unsignedgcd(unsigneda,unsignedb){if(a%b==0)returnb;elsereturngcd(b,a%b);}voidEgcd(inta,intb,int&x,int&y){//ax-by=1if(b==0||a==0){x=1;y=0;return;}if(ab){Egcd(a,b%a,x,y);x=(int)(b*y+1)/a;}else{Egcd(a%b,b,x,y);y=(int)(a*x-1)/b;}}voidRSA(){intp,q,N,Y;printf(请输入素数p和q:);scanf(%d%d,&p,&q);n=p*q;N=(p-1)*(q-1);//printf(n=%dN=%d\n,n,N);srand((unsigned)time(NULL));//初始化随机数while(1)//产生随机整数e，e与N互质{e=rand()%N;//printf(e==%d\n,e);if(e==0)continue;if(gcd(N,e)==1){break;}}//printf(e=%d\n,e);Egcd(e,N,d,Y);//printf(d=%dY=%d\n,d,Y);printf(公钥PU={e=%d,n=%d}\n,e,n);printf(私钥PR={d=%d,n=%d}\n,d,n);}voidencrypt()//加密函数{len=strlen(s);//hgprintf(len=%d\n,len);for(i=0;ilen;i++)//去掉s[100]中的空格{if(s[i]97||s[i]122){b[k]=i;k++;for(j=i;jlen-1;j++){s[j]=s[j+1];}len--;}}s[len]='\0';//结束符printf(密文是：);for(i=0;ilen;i++){C=1;//printf(shiji=%d\n,s[i]-97);for(intj=0;je;j++){C=(C*(s[i]-97))%n;//printf(C=%ld\n,C);}str[i]=C;printf(%d,str[i]);}printf(\n);}voiddecrypt()//解密函数{c=(char*)malloc(len*sizeof(int));for(i=0;ilen;i++)//实现解密{C=1;for(intj=0;jd;j++){C=(C*(str[i]))%n;//printf(C=%ld\n,C);}//printf(C=%d\n,C);c[i]=C+97;}c[i]='\0';//puts(c);for(intz=0;zk;z++)//加空格{for(i=0;ilen;i++){if(i==b[z]){for(j=len;ji;j--){c[j]=c[j-1];}c[i]='';len++;b[z+1]=b[z+1]+(z+1);break;}}}c[len]='\0';printf(明文：);puts(c);}intfunction()//系统功能选择页面{intchoice;printf(==============================================================\n);printf(欢迎进入RSA算法\n);printf(1--加密\n);printf(2--解密\n);printf(3--退出\n);printf(==============================================================\n);printf(请输入要选择的功能号：);scanf(%d,&choice);returnchoice;}intmain(){intfunction();intfc;printf(请输入初始明文(小写)：);gets(s);//puts(s);RSA();//提供私钥和公钥while(1){fc=function();if(fc==1)//加密encrypt();elseif(fc==2)//解密decrypt();elseif(fc==3)break;elseprintf(输入有误，请重新输入！/n);}return0;}