I wasn't pretty clear on a very fundamental consideration about EPV-CORE.
EPV-CORE is based on a concept of having a "BlackBox" EPV capability at each
point in the SMTP state machine model:
connect EPV = EPVM-CIP(CIP)
HELO/EHLO EPV = EPVM-CDN(CIP,CDN)
MAIL FROM EPV = EPVM-TRP(CIP,CDN,TRP)
RCPT TO EPV = EPVM-TFP(CIP,CDN,TRP,TFP)
DATA EPV = EPVM-CDN(CIP,CDN,TRP,TFP,TPL)
In general, the EPV has six basic interpretations:
epvNone EP is non-deterministic by EPV-METHOD.
epvAccept EP was accepted by EPV-METHOD
epvReject EP was rejected by EPV-METHOD.
epvExpire EP is expired
epvAbort Server *SHOULD* abort the transaction.
epvError An error was detected by EPV-METHOD.
As far as SMTP is concern, it doesn't really matter how that result was
achieved as a blackbox model.
So for EPV-CORE-MARID, it fits very nicely like so:
connect n/a
HELO/EHLO EPV = EPVM-MARID-SPF(CIP,CDN)
MAIL FROM EPV = EPVM-MARID-SPF(CIP,TRP,PRA)
RCPT TO n/a
DATA EPV = EPVM-MARID-SENDERID(TPL)
The goal of EPV-CORE is to provide a "plug and play" prior art, open
standard model so that the internet mail system is not locked into using a
technology that a) may not be suitable for the job, b) has other society
oriented concerns.
If tomorrow we come with a better solution, like CSV or something else, no
one is locked in with deprecated methods.
For example, using CSV as a possible replacement:
connect
HELO/EHLO EPV = EPV-CORE-CSV(EPVD-CSV)
MAIL FROM
RCPT TO
DATA
Here is how the current CSV framework can be viewed based on a new
EPV-CORE-CSV framework:
EPV-CORE-CSV:
"EPV-CORE Framework for CSV"
by Hector Santos
o Summary:
The current CSV proposal can be remodeled using EPV-CORE
framework as followed:
EPV = EPV-CORE-CSV (EPVD-CSV)
where EPVD-CSV is a set process or domain elements:
CIP Client IP Address
CDN Client Domain Name, HELO/EHLO (RFC2821)
SRV Domain Name Server Database SRV record
DNA Authorization/Reputation Service
EPV-CORE-CSV provides an CSV functional model based on the result of two
CSV protocols; CSA and DNA:
EPV-CSV = EPVM-CSV(EPV-DNA, EPV-CSA)
where
EPV-CSV is the result of the EPVM-CSV method based on
the result of EPVM-DNA and EPVM-CSA methods:
EPV-DNA = EPVM-DNA (CIP,CDN,DNA,DNS)
EPV-CSA = EPVM-CSA (CIP,CDN,DNS)
--
Hector Santos, Santronics Software, Inc.
http://www.santronics.com