How to verify a X509 certificate in C

Question

I have a certificate in X509 format. this a input parameters in a function. What I would like to do is to verify the validity of the certificate. How can it be done?

X509_verify_cert();

I found this function, but this does not accept a X509* certificate, it accepts X509_store and I only have a X509.

Thanks best regards.

Answer 1

See the documentation here.

You need to create a certificate store using X509_STORE_CTX_new. Then add certificate chain using X509_STORE_CTX_set_chain. Add trusted root certificate using X509_STORE_CTX_trusted_stack. Finally add certificate to be verified using X509_STORE_CTX_set_cert.

After that call X509_verify_cert.

I hope this will help you to start on this.