802.1x Certificates

  802.1x_Zertifikate

ToDo: Page to be translated to English - any contribution is welcome!

This page summarizes the requirements for certificates and their properties, as they apply to the 802.1x (EAP-TLS) authentication of OpenStage and optiPoint IP phones.

1. Basic requirements to 802.1x certificates

• The intended purpose must be "client authentication".
• The purpose to use must be "signature and encryption".
• The type is X.509-certificate, version: 3.
• The algorithm class for the private dey is: 0xa000(5) ALG_CLASS_KEY_EXCHANGE
• Normally is used sha1RSA, however, it can be fallen back on various other algorithms, provided that these algorithms are supported by OpenSSL and e.g. Win2003.
• From DLS view there are any X.509 V3 certificates possible. The only restriction is the size (max. approx. 7kB).

Phone-certificate

• X509v3 Extended Key Usage: Client Authentication
• RSA Public Key: (1024 bit) with optiPoint, (2048 bit) with OpenStage

RADIUS-certificate

• RSA Public Key: (2048 bit)
• X509v3 extensions:
• X509v3 Key usage: critical, digital signature, key Encipherment, key agreement, certificate Sign
• X509v3 Extended key usage: server authentication, client authentication

SubCA-certificate

• RSA Public Key: (2048/4096 bit)
• X509v3 extensions:
• X509v3 Basic Constraints: critical, CA:TRUE
• X509v3 Key Usage: critical, Digital Signature, Certificate Sign, CRL Sign

RootCA-certificate

• RSA public key: (2048/4096 bit)
• X509v3 extensions:
  • X509v3 basic constraints: critical, CA:TRUE
  • X509v3 Key usage: critical, digital signature, certificate sign, CRL Sign

2. Difference between optiPoint und OpenStage

• optiPoint SIP/HFA:
  • Phone-certificate(certificate chain + priv. key in PKCS#12 container)
  • RootCA-certificate (= public key = first element of the RADIUS-certificate chain) or
  • RADIUS-certificate (= public key des RADIUS-certificates)
  • Key size: 1024 Bit
• OpenStage SIP/HFA:
  • Phone-certificate (certificate chain + priv. key in PKCS#12 container)
  • RootCA-certificate (= public key = first element of the RADIUS-certificate chain)
  • Key size: max. 2048 Bit, should be limited for reasons of the compatibility to optiPoint to 1024 bits.