certificate sanity check using wolfssl

Question

I need to test if a ECC certificate in PEM format is of good shape in C using the wolfssl library. I do not want to test any further information only if it is a certificate and not any random Base64 encoded bytes between the

-----BEGIN CERTIFICATE-----

-----END CERTIFICATE-----

lines. What is the easiest way to do so?

Answer 1

You can use the wolfSSL_X509_load_certificate_file to check if it's a valid certificate, as shown in the example bellow.

You can find the function documentation here.

#include <wolfssl/openssl/x509.h>

int is_x509_cert(const char* pem_cert_file_path) {
    WOLFSSL_X509 *cert = wolfSSL_X509_load_certificate_file(pem_cert_file_path, SSL_FILETYPE_PEM);
    if (cert != NULL) {
        wolfSSL_X509_free(cert);
        return 1;
    } else {
        return 0;
    }
}