On Wed, Apr 13, 2016 at 10:59:06AM +0100, Neil Cook wrote: > However this does bring up a good point - if I want to support STS *and* > DANE as a receiver, and have a homogeneous MX/MTA setup, i.e. not something > like the above, I would have to support the common subset of both > specifications, at least as far as MTA configuration is concerned, e.g. > no self-signed certs. That is a consequence we haven�t discussed before.
STS is WebPKI. If you want STS, you need a certificate from one of the usual CAs. With a self-signed certificate (some day just a bare public key and no certificate at all) you can only use DANE. Top 10 issuers of certs for DANE MX hosts: 172 ; Issuer = CN=StartCom Class 1 Primary Intermediate Server CA,OU=Secure Digital Certificate Signing,O=StartCom Ltd.,C=IL 166 ; Issuer = CN=COMODO RSA Domain Validation Secure Server CA,O=COMODO CA Limited,L=Salford,ST=Greater Manchester,C=GB 165 ; Issuer = CN=Let's Encrypt Authority X1,O=Let's Encrypt,C=US 91 ; Issuer = CN=StartCom Class 2 Primary Intermediate Server CA,OU=Secure Digital Certificate Signing,O=StartCom Ltd.,C=IL 90 ; Issuer = CN=Gandi Standard SSL CA 2,O=Gandi,L=Paris,ST=Paris,C=FR 81 ; Issuer = CN=StartCom Class 1 DV Server CA,OU=StartCom Certification Authority,O=StartCom Ltd.,C=IL 63 ; Issuer = CN=Let's Encrypt Authority X3,O=Let's Encrypt,C=US 62 ; Issuer = CN=RapidSSL SHA256 CA - G3,O=GeoTrust Inc.,C=US 38 ; Issuer = CN=WoSign CA Free SSL Certificate G2,O=WoSign CA Limited,C=CN 33 ; Issuer = CN=CAcert Class 3 Root,OU=http://www.CAcert.org,O=CAcert Inc. ( Note some of the MX hosts support many hundreds of domains, the above counts the issuer just once for each issued certificate, not once per domain served. ) -- Viktor. _______________________________________________ Uta mailing list Uta@ietf.org https://www.ietf.org/mailman/listinfo/uta