At 09:09 AM 4/18/2016, you wrote:
On Mon, 18 Apr 2016, david wrote:
FOLLOWUP & REPORT
I had lots of suggestions, and the most persuasive was to try OpenVPN. I already had a CA working, so issuing certificates was easy. The HOW-TO guides were less helpful than I could hope, but comparing several of them, applying common sense, and trying things out, I arrived at a dead-end. Here's essentially what happened:
- None of the HOW-TOs were very clear about the need to add some
attributes to a certificate, keyUsage and extendedKeyUsage. They had different values for server and client. OpenSSL documentation was a big vague on how to add them, but I think I did - the print out of the entity certificates showed the values. The attempt to connect failed. The client log is below. I think it's complaining that the CA certificate doesn't have the ke Usage extension, which makes no sense to me. Such an extension should be in the end-entity certificate, not the CA's, unless I'm wrong. I checked the server and really think that the certificates are in the right place.
Here's how I managed that in my openssl.cnf file. Lots of bits ellided for clarity's sake:
### start ### [ ca ] default_ca = CA_default
[ CA_default ] x509_extensions = server_cert
[ server_cert ] basicConstraints=CA:FALSE keyUsage = nonRepudiation, dataEncipherment, digitalSignature, keyEncipherment extendedKeyUsage = serverAuth, clientAuth nsCertType = server, client ### end ###
I think the nsCertType directive may be unnecessary these days, but I keep it around because it doesn't hurt anything.
The important bit is the extendedKeyUsage line; I'm pretty sure that an OpenVPN server needs the serverAuth extension. For instance, here is the X509 extensions configuration for a server used by EasyRSA:
basicConstraints = CA:FALSE subjectKeyIdentifier = hash authorityKeyIdentifier = keyid,issuer:always extendedKeyUsage = serverAuth,clientAuth keyUsage = digitalSignature,keyEncipherment
You can ask openssl to tell you the purpose of a certificate:
[bash]$ openssl x509 -noout -purpose -in cert.pem | grep SSL SSL client : Yes SSL client CA : No SSL server : Yes SSL server CA : No Netscape SSL server : Yes Netscape SSL server CA : No
Anyway, those are the extensions that should do away with these errors:
Mon Apr 18 05:34:50 2016 VERIFY OK: depth=1, C=US, ST=California, L=San Francisco, OU=Certificate Authority, O=XXXX, CN=X.X.X Mon Apr 18 05:34:50 2016 Certificate does not have key usage extension
-- Paul Heinlein <> heinlein@madboa.com <> http://www.madboa.com/
Paul Two things... First, the diagnostic I got referenced the server's CA certificate. And that confuses me.
Second, when I look server's purpose, using the openssl x509 -purpose command, I get:
SSL client : No SSL client CA : No SSL server : Yes SSL server CA : No Netscape SSL server : Yes Netscape SSL server CA : No
When looking at the CLIENT's purpose, I get
SSL client : Yes SSL client CA : No SSL server : No SSL server CA : No Netscape SSL server : No Netscape SSL server CA : No
The difference between what I have and what you reported is that I've got SSL Client NO on the server, and SSL server NO on the client, which makes sense to me. The CA certificate itself, says:
Certificate purposes: SSL client : Yes SSL client CA : Yes SSL server : Yes SSL server CA : Yes Netscape SSL server : Yes Netscape SSL server CA : Yes S/MIME signing : Yes S/MIME signing CA : Yes S/MIME encryption : Yes S/MIME encryption CA : Yes CRL signing : Yes CRL signing CA : Yes Any Purpose : Yes Any Purpose CA : Yes OCSP helper : Yes OCSP helper CA : Yes Time Stamp signing : No Time Stamp signing CA : Yes
Advice would be appreciated.
David