pliki:

main2.c

main2.exe

main2_patched.exe

#include <stdio.h>
 
int main() {
    char key[100];
    char valid[] = "AAAA-Z10N-42-OK";
    int i = 0;
    int match = 1;
    int ch;
 
    printf("Enter license key: ");
 
    // Read input manually, character by character
    while (i < 100) {
        ch = getchar();
        if (ch == '\n' || ch == EOF) {
            key[i] = 0;
            break;
        }
        key[i] = ch;
        i++;
    }
 
    // Compare each character manually
    i = 0;
    while (valid[i] != 0 && key[i] != 0) {
        if (valid[i] != key[i]) {
            match = 0;
            break;
        }
        i++;
    }
 
    // Also check if lengths match
    if (valid[i] != key[i]) {
        match = 0;
    }
 
    // Output result
    if (match) {
        const char *msg = "Access Granted!\n";
        for (i = 0; msg[i] != 0; i++) {
            putchar(msg[i]);
        }
    } else {
        const char *msg = "Wrong!\n";
        for (i = 0; msg[i] != 0; i++) {
            putchar(msg[i]);
        }
    }
	getchar();
    return 0;
}

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