Example 1. Open and close.

    CST * storage = CST_open_file("storage.cst", FALSE, NULL);

    X509 * cert = ... // Some cert received from server

    if (CST_is_valid(storage, cert))
    {
        printf("Certificate is valid");
    }
    else
    {
        printf("Certificate expired, have not valid sign or signed by untrusted...");
    }

    CST_free(storage);

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