是DER格式ASN1编码的X509证书吗？

Question

I'm using OpenSSl to encrypt and decrypt files based on CMS/SMIME. Normally I load certificates with rcert = PEM_read_bio_X509(tbio, NULL, 0, NULL); but this is only for PEM formatted files I guess. I haven't found any der.h header or something similar.

So is there a way in OpenSSL to load DER formatted certificates? I've found the load function for ASN1 format which uses OpenSSL intern.

if  (format == FORMAT_ASN1)
        x=d2i_X509_bio(cert,NULL);

But can that be used for DER which is binary?

Answer 1

DER确实使用ASN.1编码，而d2i_*()函数系列是加载DER文件的方法。