guide · how-to
Convert an AS2 certificate between PEM and DER
Different AS2 platforms expect different certificate encodings. PEM (base64, -----BEGIN CERTIFICATE-----) and DER (raw binary) hold the same certificate — just encoded differently.
PEM to DER
openssl x509 -in cert.pem -outform der -out cert.der
DER to PEM
openssl x509 -in cert.der -inform der -out cert.pem
Confirm it's the same certificate
The fingerprint doesn't change across encodings. Paste either file into the inspector below (it accepts PEM and DER) and compare the SHA-256 — if it matches what your partner expects, you converted the right file and nothing was corrupted.
Only ever convert and send public certificates. If a file contains
PRIVATE KEY or is a .pfx/.p12, it holds a private key — never send that to a partner. The inspector refuses such files by design.try it
Paste a certificate
public certificate — PEM or DER, never uploaded
loading inspector…