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> RADIUS secret key also leaked, so propably it is possible to break into EAP session which infers session secret key for StrongSwan. Could you elaborate on th
by xvector 7y ago
> RADIUS secret key also leaked, so propably it is possible to break into EAP session which infers session secret key for StrongSwan.
Could you elaborate on this? I am familiar with PKI so the first part makes sense, but I am not familiar with the intricacies of VPNs so I am not sure what this means.
- Snawoot 7y agoWhen StrongSwan EAP-RADIUS plugin is in use, authentication delegated to RADIUS server. Actual EAP handshake occurs between VPN client and RADIUS server. [1] Some EAP authentication methods (namely, EAP-MSCHAPv2 and EAP-TLS) export Master Session Key, which is exported to StrongSwan via MS-MPPE-Send-Key/MS-MPPE-Recv-Key EAP attributes. [2] So, MSK derived on RADIUS side and sent to StrongSwan. Eavesdropper with knowledge of RADIUS secret key capable to intercept and decrypt such EAP payload. [1] - https://wiki.strongswan.org/projects/strongswan/wiki/EAPRadius#EAP-Radius https://wiki.strongswan.org/projects/strongswan/wiki/EAPRadi... [2] - https://tools.ietf.org/html/rfc5216#section-2.3 https://tools.ietf.org/html/rfc5216#section-2.3