Zertifikat

Dateitypen

• Encodings (also used as extensions)
  • .DER = The DER extension is used for binary DER encoded certificates. These files may also bear the CER or the CRT extension.
  • .PEM = The PEM extension is used for different types of X.509v3 files which contain ASCII (Base64) armored data prefixed with a “—– BEGIN …” line.
• Extensions:
  • .CRT = The CRT extension is used for certificates. The certificates may be encoded as binary DER or as ASCII PEM. The CER and CRT extensions are nearly synonymous. Most common among *nix systems
  • .CER = alternate form of .crt (Microsoft Convention) You can use MS to convert .crt to .cer (.both DER encoded .cer, or base64[PEM] encoded .cer) The .cer file extension is also recognized by IE as a command to run a MS cryptoAPI command (specifically rundll32.exe cryptext.dll,CryptExtOpenCER) which displays a dialogue for importing and/or viewing certificate contents.
  • KEY = The KEY extension is used both for public and private PKCS#8 keys. The keys may be encoded as binary DER or as ASCII PEM.

Wildcard-Zertifikat

ROOT_CA=rootCA
VALID_DAYS=1000
CERT=vmd9593
# Schlüssel generieren, kein Passwort:
openssl genrsa -out $CERT.key 2048

# Zertifikatsanfrage generieren: CN (Common Name) evt. IP-Adresse
# Bei CN (Common Name) eintragen: "*.f-r-e-i.de"
openssl req -new -key $CERT.key -out $CERT.csr -sha512 -config ./openssl.cnf

# Signieren:
openssl x509 -req -days $VALID_DAYS -in $CERT.csr -signkey ${ROOT_CA}.key -out $CERT.pem