# x509: certificate signed by unknown authority
**URL:** https://forum.syncthing.net/t/x509-certificate-signed-by-unknown-authority/10957
**Category:** Support
**Created:** [November 16, 2017, 2:50pm UTC](https://forum.syncthing.net/t/x509-certificate-signed-by-unknown-authority/10957 "2017-11-16T14:50:57Z")
**Posts on this page:** 9
**Page:** 1
### Author:  [@graykick](https://forum.syncthing.net/u/graykick)
#### Post date: [November 16, 2017, 2:50pm UTC](https://forum.syncthing.net/t/x509-certificate-signed-by-unknown-authority/10957/1 "2017-11-16T14:50:57Z")
I wanna use my own discovery server. So I set up the server with docker(I reference [this article](https://forum.syncthing.net/t/docker-syncthing-and-syncthing-discovery-behind-nginx-reverse-proxy-with-lets-encrypt/6880/7))
So, I use let’s encrypt to get SSL signed CA. And I check through the Chrome browser, the CA certification is successful.
But syncthing is occure x509 error.
```
`global.go:224: DEBUG: announce POST: Post https://discovery.studygram.kr: x509: certificate signed by unknown authority`
```
My Environments are
- syncthing is built in window 10 (amd64)
- run syncthing(version is 0.14.39) in ubuntu Ubuntu 16.04.2 LTS (amd64)
Thank you in advance
---
### Author:  [@AudriusButkevicius](https://forum.syncthing.net/u/AudriusButkevicius)
#### Post date: [November 16, 2017, 2:56pm UTC](https://forum.syncthing.net/t/x509-certificate-signed-by-unknown-authority/10957/2 "2017-11-16T14:56:49Z")
I think Chrome ships it’s own CA bundle. Go uses your OS bundle. I suspect if you try curl, it will fail with the same error. You need to update your OS cert bundle.
---
### Author:  [@graykick](https://forum.syncthing.net/u/graykick)
#### Post date: [November 16, 2017, 3:01pm UTC](https://forum.syncthing.net/t/x509-certificate-signed-by-unknown-authority/10957/3 "2017-11-16T15:01:49Z")
Thank you for your very quick reply. I’ll check this. Thank you so much.
---
### Author:  [@graykick](https://forum.syncthing.net/u/graykick)
#### Post date: [November 16, 2017, 4:26pm UTC](https://forum.syncthing.net/t/x509-certificate-signed-by-unknown-authority/10957/4 "2017-11-16T16:26:45Z")
I checked your advice.
OS cert bundle is not a problem.
[https://helloworld.letsencrypt.org/](https://helloworld.letsencrypt.org/) This site is CA signed by Let’s Encrypt Authority X3.(same as me)
The result of `curl https://helloworld.letsencrypt.org` is successfully print html.
But, My discovery server url is print
`curl: (60) SSL certificate problem: unable to get local issuer certificate`
I think that my nginx setting have a problem. But I dont know what is it…
Below is My nginx conf file. please let me know What is problem.
```
proxy_http_version 1.1;
proxy_buffering off;
proxy_set_header Host $http_host;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection $proxy_connection;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto $proxy_x_forwarded_proto;
proxy_set_header X-SSL-Cert $ssl_client_cert;
server {
server_name _; # This is just an invalid value which will never trigger on a real hostname.
listen 80;
access_log /var/log/nginx/access.log vhost;
return 503;
}
upstream discovery.studygram.kr {
## Can be connect with "sdd_default" network
# syncthing_discovery_run
server 172.19.0.2:8443;
}
server {
server_name discovery.studygram.kr;
listen 80 ;
access_log /var/log/nginx/access.log vhost;
return 301 https://$host$request_uri;
}
server {
server_name discovery.studygram.kr;
listen 443 ssl http2 ;
access_log /var/log/nginx/access.log vhost;
ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
ssl_ciphers ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-DSS-AES128-GCM-SHA256:kEDH+AESGCM:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA:ECDHE-ECDSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-DSS-AES128-SHA256:DHE-RSA-AES256-SHA256:DHE-DSS-AES256-SHA:DHE-RSA-AES256-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:AES:CAMELLIA:DES-CBC3-SHA:!aNULL:!eNULL:!EXPORT:!DES:!RC4:!MD5:!PSK:!aECDH:!EDH-DSS-DES-CBC3-SHA:!EDH-RSA-DES-CBC3-SHA:!KRB5-DES-CBC3-SHA;
ssl_prefer_server_ciphers on;
ssl_session_timeout 5m;
ssl_session_cache shared:SSL:50m;
ssl_certificate /etc/nginx/certs/discovery.studygram.kr.crt;
ssl_certificate_key /etc/nginx/certs/discovery.studygram.kr.key;
ssl_trusted_certificate /etc/nginx/certs/discovery.studygram.kr.chain.pem;
ssl_dhparam /etc/nginx/certs/discovery.studygram.kr.dhparam.pem;
add_header Strict-Transport-Security "max-age=31536000";
ssl_verify_client optional_no_ca;
include /etc/nginx/vhost.d/default;
location / {
proxy_pass http://discovery.studygram.kr;
}
}
```
Thank you in abvance
---
### Author:  [@calmh](https://forum.syncthing.net/u/calmh)
#### Post date: [November 16, 2017, 4:28pm UTC](https://forum.syncthing.net/t/x509-certificate-signed-by-unknown-authority/10957/5 "2017-11-16T16:28:51Z")
Make sure you have any intermediate certificates in the file as well.
---
### Author:  [@graykick](https://forum.syncthing.net/u/graykick)
#### Post date: [November 16, 2017, 4:39pm UTC](https://forum.syncthing.net/t/x509-certificate-signed-by-unknown-authority/10957/6 "2017-11-16T16:39:28Z")
```
// this is fullchain of lets encrypt. It has cert and chain (certificate and intermediate certificates)
ssl_certificate /etc/nginx/certs/discovery.studygram.kr.crt;
// this is key file
ssl_certificate_key /etc/nginx/certs/discovery.studygram.kr.key;
// this is (intermediate certificates)
ssl_trusted_certificate /etc/nginx/certs/discovery.studygram.kr.chain.pem;
```
This is my nginx setting. I think that I have intermediate certificates. Is it right? But, not working yet.
---
### Author:  [@calmh](https://forum.syncthing.net/u/calmh)
#### Post date: [November 16, 2017, 6:21pm UTC](https://forum.syncthing.net/t/x509-certificate-signed-by-unknown-authority/10957/7 "2017-11-16T18:21:28Z")
I don’t know, but this seems an nginx or certificate setup issue.
---
### Author:  [@graykick](https://forum.syncthing.net/u/graykick)
#### Post date: [November 17, 2017, 2:13am UTC](https://forum.syncthing.net/t/x509-certificate-signed-by-unknown-authority/10957/8 "2017-11-17T02:13:36Z")
My mistake… I added intermediate certificates to nginx, But I didn’t restart it…
I’m really sorry for I’m too stupid.
Thank you for your kind reply.
---
### Author:  [@system](https://forum.syncthing.net/u/system)
#### Post date: [December 17, 2017, 2:17am UTC](https://forum.syncthing.net/t/x509-certificate-signed-by-unknown-authority/10957/9 "2017-12-17T02:17:58Z")
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