Facebook cannot verify my SSL certificate - facebook-graph-api

Question

I am trying to register my app with FB Realtime Graph updates and having issues with FB verifying my callback URL. I can successfully register (and receive updates) with FB using HTTP but I need to switch to HTTPS.
curl -XPOST -i -v \
-d 'access_token=$OAUTH_TOKEN' \
-H 'Accept: application/json' -H 'Content-Type: application/json' \
-d "object=user" -d "fields=friends,name" -d "callback_url=https://$MY_RUL" \
-d "verify_token=$VERIFY_TOKEN" "https://graph.facebook.com/$APP_ID/subscriptions"
and yes, I am using the correct values in all $ variables.
I receive an HTTP 400 Bad Request with body:
{"error":{"message":"(#2200) callback verification failed: SSL certificate problem, verify that the CA cert is OK. Details:\nerror:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed","type":"OAuthException"}}
But I do have SSL setup correctly, as far as I can tell. I can issue other CURL calls against my HTTPS endpoint.
$ curl -i https://foo.com/health
HTTP/1.1 200 OK
Content-Type: text/plain
Date: Mon, 17 Oct 2011 19:56:42 GMT
Status: 200
X-Rack-Cache: miss
X-Runtime: 0.002040
Content-Length: 21
Connection: keep-alive
pong
Where is the issue, is it on my end or facebooks?
Note: I see similar issues here on SO especially in regards to Ruby / HTTPS, such as:
SSL_connect returned=1 errno=0 state=SSLv3 read server certificate B: certificate verify failed
But I dont think this is my issue, and again, I am attempting to us CURL directly to ensure its not a Ruby/OpenSSL issue.
Plus, since FB says callback verification failed it makes me think the error is on FBs end when it is verifying MY callback URL.
Any help would be appreciated.

Answer 1

We don't have your parent certificate in our CA chain since its relatively new. You'll need to include all of the parent certificates in the chain. I'm guessing the step got skipped during install.
See the concatenate step on https://knowledge.rapidssl.com/support/ssl-certificate-support/index?page=content&id=SO17664