Re: [openssl-users] How to use ADH with OpenSSL 1.1.0
>> Then I tried adding :@SECLEVEL=0 to my cipher suite list. That made the >> trick, but as far as I understand, it switches off some other cipher checks. >> What's the recommended way of allowing ADH? >For now just @SECLEVEL=0. There's not yet a more fine-grained to set the >security >level for crypto parameters but allow certificate-less key exchange. If >you're willing >to allow MiTM attacks, then downgrades are of scope, and the peers will >negotiate >the best available ciphers, so @SECLEVEL=0 is probably fine, you'll still get >strong ciphers. >You can also limit the cipher list to exclude anything you feel is too weak to >offer. Since we never allow unauthenticated cipher suites in production configurations, it's actually not a problem with the @SECLEVEL solution for those test systems where we do use ADH. Glad that I don't have to use a modified callback. Thanks a lot, Per -- openssl-users mailing list To unsubscribe: https://mta.openssl.org/mailman/listinfo/openssl-users
Re: [openssl-users] How to use ADH with OpenSSL 1.1.0
> On Apr 12, 2018, at 7:12 AM, Frykenvall, Per wrote: > > Then I tried adding :@SECLEVEL=0 to my cipher suite list. That made the > trick, but as far as I understand, it switches off some other cipher checks. > What's the recommended way of allowing ADH? For now just @SECLEVEL=0. There's not yet a more fine-grained to set the security level for crypto parameters but allow certificate-less key exchange. If you're willing to allow MiTM attacks, then downgrades are of scope, and the peers will negotiate the best available ciphers, so @SECLEVEL=0 is probably fine, you'll still get strong ciphers. You can also limit the cipher list to exclude anything you feel is too weak to offer. -- Viktor. -- openssl-users mailing list To unsubscribe: https://mta.openssl.org/mailman/listinfo/openssl-users
[openssl-users] How to use ADH with OpenSSL 1.1.0
Hi, I need to permit some anonymous Diffie-Hellman ciphers in OpenSSL. This worked fine until I installed 1.1.0h when I get "no shared cipher". I debugged and found the cause in ssl_security_default_callback, ssl_cert.c line 1028: /* No unauthenticated ciphersuites */ if (c->algorithm_auth & SSL_aNULL) return 0; So do I need to have my own callback, using SSL_CTX_set_security_callback? The manual page is not very informative and I'm not sure about how to implement the callback. I wouldn't like to duplicate all the other checks of the default callback. Then I tried adding :@SECLEVEL=0 to my cipher suite list. That made the trick, but as far as I understand, it switches off some other cipher checks. What's the recommended way of allowing ADH? Best regards, Per -- openssl-users mailing list To unsubscribe: https://mta.openssl.org/mailman/listinfo/openssl-users