Question

A CERTAIN program to user's password containing rules such as least n length, one uppercase, lowercase, one digit and white space is given as the code down below. So, simiiar to those rules, I need the code for the following questions post in pictures such as no more three consecutive letters of English alphabets, password should not contain User name and so on.

//GOAL: To learn how to create that make strong passwords

//Purpose: 1)To learn some rules that makes strong passwords

// 2)To understand basic character function such as:

// 1)isalpha(), 2)isdigit(), 3)isalnum(), 4)islower()

// 5)isupper(), 6)ispunct(), 7)isprint(), 8)isspace(), 9)toupper(), 10)tolower()

// 3) To understand how to use basic string function such as:

// i)strlen(s1), ii)strcpy(s1,s2) like s1 = s2

// iii)strcat(s1,s2) concatenates s2 to the end of s1

// iv)strcmp(s1,s2) which returns the difference of the ASCII value of the first

// two non-matching characters in string s1 and s2.

#include<stdio.h>

#include<ctype.h>

#include<string.h>

#define MAX_STRING_LENGTH 20

int main()

{

char s1[ MAX_STRING_LENGTH];

int n;

printf("\n Please enter the string that you would like as your passwor:");

//scanf("%s",s1);

gets(s1);

printf("\n The password you have chosen is: %s", s1);

printf("\n What is the minimun length of a good/strong passwor:");

scanf("%d",&n);

if (strlen(s1)< n)

{

printf("\n Your password does not qualify, since it is not long enough!!");

printf("\ Your password if of length %d. Minimum password length is %d", strlen(s1),n);

}

else

{

printf("\n You have chosen a good password. It meet the minimun length criterion.");

}

// Rule 2.

//..............................................................................................

int i;

int num_lower = 0;

int num_upper = 0;

int num_digit = 0;

for( i =0; i<=strlen(s1) -1; i++)

{

if(isupper(s1[i]))

{

num_upper ++;

}

if (islower(s1[i]))

{

num_lower ++;

}

if (isdigit(s1[i]))

{

num_digit ++;

}

}

if (num_upper >0 && num_lower >0 && num_digit >0)

{

printf("\n The password is Stong , because it has lowercase character,\n");

printf("\n Uppercase characters, and digit in the password.");

printf("\n Your password is strong, since it meets the Rule 2:");

}

// Rule 3: Add a non-alphabetic character that is not a digit

//..........................................................

int num_special_character = 0;

for(i=0; i<=strlen(s1)-1; i++)

{

if(! isalnum(s1[i]))

{

num_special_character ++;

}

}

if (num_special_character == 0)

{

printf("\ Your password is not good....");

printf("\ It is missing a special character, such as +-*/<>...etc.");

}

else

{

printf("\n Your password is strong, since it meets the Rule 3:");

}

//Rule:4

//..................................

int num_whitespaces_total =0;

for( i=0; i<=255; i++)

{

if(isspace(i))

{

printf("\n %d %c is a white space", i,i);

num_whitespaces_total ++;

}

}

printf("\n The 8-bit Extended ASCII code.... has %d WHITE SPACE CHARACTER", num_whitespaces_total);

int num_white_spaces =0;

for( i=0; i<=strlen(s1)-1; i++)

{

if(isspace(s1(i)))

{

printf("\n %d %c is a white space", i,i);

num_white_spaces ++;

}

}

if (num_white_spaces == 0)

{

printf("\n Your password is bad:");

}

else

{

printf("It good password:");

}

getchar();

return 0;

}

Develop a code for C program to make sure that your program has the following rules. Add the following rule: The password should not contain any word from the dictionary You may use your dictionary from Assignment Add the following rule: Your password should not contain three or more consecutive letters of the English al also disallow 3 consecutive digits. e.g. "abcd1234temp" would be considered a bad password. phabet". You should Add the following rule: "Your password should not contain three or more consecutive letters of the English alphabet that are adjacent keys on the keyboard". You should also disallow 3 consecutive digits. e.g.. "qwerty 123asdfg" would be considered a bad password. Your password should not contain the User name. No three consecutive letters of the User name should be allowed in the password. e.g.. Username: Mike Password: Mike23vnkdtrp8 should not be allowed. Write a short note on the difficulties you encountered in implementing your password checker program above. Explain how you overcame those difficulties. How strong is your password? Explain briefly. State (but not implement) any 2 additional criteria for an even stronger password. How hard would they be to implement? Explain.

Answer 1

#include<stdio.h>

#include<ctype.h>

#include<stdlib.h>

#include<string.h>

#define MAX_STRING_LENGTH 20

int main(int argc, char const *argv[])

{

char s1[ MAX_STRING_LENGTH];

printf("\n Please enter the string that you would like as your passwor:");

gets(s1);

printf("\n The password you have chosen is: %s\n", s1);

// Rule 1 - The password should not contain any word from dictionary

/*

Since, I don't have access to dictionary. I will skip it here

*/

// Rule 2 - The password should not contain 3 or more consecutive english alphabets

int consecutive_english_alpha_count = 0, i=0;

int good_password = 1;

for(i=0; i< strlen(s1); i++)

{

if(isalpha(s1[i])) {

consecutive_english_alpha_count++;

}

else {

consecutive_english_alpha_count = 0;

}

if(consecutive_english_alpha_count == 3) {

good_password = 0;

break;

}

}

if(good_password == 1)

{

printf("Great Password as it didn't have 3 consecutive english alphabets\n");

}

else

{

printf("OOPs! Your password have 3 consecutive english characters\n");

}

// Rule 3 - Password having 3 or more consecutive english characters from keyboard

// keyboard below containes all adjacent charaters on keyboard

char *keyboard = "qwertyuiopasdfghjklzxcvbnm";

// now we will generate all substring of length 3 from password and search that substring in

// the keyboard string. If we found the match, then password is bad else good

int k = 3;

good_password = 1;

for(i=0; i+k-1<strlen(s1); i++)

{

char *temp = (char*) malloc(k);

strncpy(temp, s1+i, k);

// printf("substring from %d is %s\n", i, temp );

if(strstr(keyboard, temp) != NULL) {

good_password = 0;

break;

}

}

if(good_password == 1)

printf("Good Password! No 3 adjacent characters found in password which are present in keyboard\n");

else

printf("Bad Password! 3 adjacent characters found in password which are also present in keyboard\n");

// Rule 4 - No 3 consecutive letters of username present in password

// First we will take the user input

char user[MAX_STRING_LENGTH];

printf("\n Please enter the username: ");

gets(user);

printf("\n The username you have entered is: %s\n", user);

// We will follow the same approach as Rule 3. The only change is keyboard pointer is replaced with username

// now we will generate all substring of length 3 from password and search that substring in

// the username string. If we found the match, then password is bad else good

good_password = 1;

for(i=0; i+k-1<strlen(s1); i++)

{

char *temp = (char*) malloc(k);

strncpy(temp, s1+i, k);

// printf("substring from %d is %s\n", i, temp );

if(strstr(user, temp) != NULL) {

good_password = 0;

break;

}

}

if(good_password == 1)

printf("Good Password! No 3 adjacent characters found in password which are present in username\n");

else

printf("Bad Password! 3 adjacent characters found in password which are also present in username\n");

return 0;

}