DER (Distinguished Encoding Rules)

wikipedia:DER

openssl x509 -inform der -in cerfile.cer -noout -text

PKCS7 chain in DER format. These files also may be named with a .p7b extension

Related

• To view .cer files
• DIVA

See also

• X.509, ASN.1, openssl x509, .pem, der, PFX, PKCS, SAN, openssl x509, CSR, Java KeyStore (JKS), Certificate Revocation List (CRL), Extended Key Usages (ECU), PKIX
• Certificate, CSR (PKCS10), /etc/letsencrypt/csr/, openssl req, X.509, [.pem, .cer, .csr], Kubernetes CertificateSigningRequest