RSA.rar_c++ builder RSA_generation_rsa_rsa c++

#include <stdio.h> #include <stdlib.h> #include<string.h> #include<conio.h> #include<math.h> #include<ctype.h> int gcd(int ,int ); int gen_d(int ,int ); int max_power(int ,int ,int ); int main() { char pl[100]; int c[100],cipher[100],k[100]; int phi,l,n,e,d,i,p,q; printf("\nEnter two large prime no p & q="); scanf("%d %d",&p,&q); n=p*q; phi=(p-1)*(q-1); for (i = 1; i <= phi; i++) { e = rand() % phi + 1; if (gcd(phi,e)==1) { printf("public key(e,n)=(%d,%d)", e,n); break; } } d=gen_d(phi,e); printf("\nprivate key(d,n)=(%d,%d)",d,n); printf("\nenter the plaintext="); scanf("%s",pl); l=strlen(pl); for(i=0;i<l;i++){c[i]=pl[i];} printf("\nEncryption=>>cipher is ::"); for(i=0;i<l;i++) { k[i]=max_power(c[i],e,n); printf("%c",toascii(k[i])); } int j=0; printf("\nDecryption=>>plain text is::"); for(i=0;i<l;i++) { j=max_power(k[i],d,n); printf("%c",toascii(j)); } getch(); return 0; } int gcd(int x,int y) { int r1=x; int r2=y,q,r; while(r2>0) { q=r1/r2; r=r1-q*r2; r1=r2; r2=r; } return(r1); } int gen_d(int x1,int y1) { int r1=x1,r2=y1,t1=0,t2=1,r,q,t; while(r2>0) { q=r1/r2; r=r1-q*r2; r1=r2; r2=r; t=t1-q*t2; t1=t2; t2=t; } return t1; } int max_power(int base,int exp,int mod) { if (exp == 0) return 1; else if (exp%2 == 0) { int mysqrt = max_power(base, exp/2, mod); return (mysqrt*mysqrt)%mod; } else return (base*max_power(base, exp-1, mod))%mod; }