问题
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?
回答1:
DER is indeed encoded using ASN.1, and the d2i_*() family of functions is the way to load a DER file.
来源：https://stackoverflow.com/questions/9499670/is-a-x509-certificate-in-der-format-asn1-encoded