M4C/password_validator.cpp at master · KrishKyada/M4C · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
#include <iostream>
#include <regex>
#include <string>
using namespace std;

int main() {
    cout << "Content-type:text/html\r\n\r\n";

    string query;
    getline(cin, query);

    string key = "password=";
    string password = "";
    size_t pos = query.find(key);
    if (pos != string::npos)
        password = query.substr(pos + key.length());

    // Decode '+' as space (optional improvement)
    for (char &c : password)
        if (c == '+') c = ' ';

    // Regex for password validation (DFA equivalent)
    regex pattern("^(?=.*[A-Z])(?=.*[a-z])(?=.*[0-9])(?=.*[@#$%^&+=!]).{8,}$");

    cout << "<html><body style='font-family:Arial;text-align:center;padding:20px;'>";

    if (regex_match(password, pattern)) {
        cout << "<h2 style='color:green;'>✅ Password is Valid!</h2>";
        cout << "<p>Great! Your password meets all DFA and regex conditions.</p>";
    } else {
        cout << "<h2 style='color:red;'>❌ Invalid Password!</h2>";
        cout << "<p>The password must include:</p>";
        cout << "<ul style='text-align:left;display:inline-block;'>";
        cout << "<li>At least 8 characters</li>";
        cout << "<li>At least one uppercase letter</li>";
        cout << "<li>At least one lowercase letter</li>";
        cout << "<li>At least one digit</li>";
        cout << "<li>At least one special character (@#$%^&+=!)</li>";
        cout << "</ul>";
    }

    cout << "</body></html>";
    return 0;
}