---
stage: Systems
group: Distribution
info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/product/ux/technical-writing/#assignments
type: reference
---
# Troubleshooting SSL **(FREE SELF)**
This page contains a list of common SSL-related errors and scenarios that you
may encounter while working with GitLab. It should serve as an addition to the
main SSL documentation:
- [Omnibus SSL Configuration](https://docs.gitlab.com/omnibus/settings/ssl.html).
- [Self-signed certificates or custom Certification Authorities for GitLab Runner](https://docs.gitlab.com/runner/configuration/tls-self-signed.html).
- [Configure HTTPS manually](https://docs.gitlab.com/omnibus/settings/ssl.html#configure-https-manually).
## Using an internal CA certificate with GitLab
After configuring a GitLab instance with an internal CA certificate, you might
not be able to access it by using various CLI tools. You may experience the
following issues:
- `curl` fails:
```shell
curl "https://gitlab.domain.tld"
curl: (60) SSL certificate problem: unable to get local issuer certificate
More details here: https://curl.haxx.se/docs/sslcerts.html
```
- Testing by using the [rails console](../operations/rails_console.md#starting-a-rails-console-session)
also fails:
```ruby
uri = URI.parse("https://gitlab.domain.tld")
http = Net::HTTP.new(uri.host, uri.port)
http.use_ssl = true
http.verify_mode = 1
response = http.request(Net::HTTP::Get.new(uri.request_uri))
...
Traceback (most recent call last):
1: from (irb):5
OpenSSL::SSL::SSLError (SSL_connect returned=1 errno=0 state=error: certificate verify failed (unable to get local issuer certificate))
```
- The error `SSL certificate problem: unable to get local issuer certificate`
is displayed when setting up a [mirror](../../user/project/repository/mirror/index.md)
from this GitLab instance.
- `openssl` works when specifying the path to the certificate:
```shell
/opt/gitlab/embedded/bin/openssl s_client -CAfile /root/my-cert.crt -connect gitlab.domain.tld:443 -servername gitlab.domain.tld
```
If you have the previously described issues, add your certificate to
`/etc/gitlab/trusted-certs`, and then run `sudo gitlab-ctl reconfigure`.
## X.509 key values mismatch error
After configuring your instance with a certificate bundle, NGINX may display
the following error message:
`SSL: error:0B080074:x509 certificate routines:X509_check_private_key:key values mismatch`
This error message means that the server certificate and key you have provided
don't match. You can confirm this by running the following command and then
comparing the output:
```shell
openssl rsa -noout -modulus -in path/to/your/.key | openssl md5
openssl x509 -noout -modulus -in path/to/your/.crt | openssl md5
```
The following is an example of an md5 output between a matching key and
certificate. Note the matching md5 hashes:
```shell
$ openssl rsa -noout -modulus -in private.key | openssl md5
4f49b61b25225abeb7542b29ae20e98c
$ openssl x509 -noout -modulus -in public.crt | openssl md5
4f49b61b25225abeb7542b29ae20e98c
```
This is an opposing output with a non-matching key and certificate which shows
different md5 hashes:
```shell
$ openssl rsa -noout -modulus -in private.key | openssl md5
d418865077299af27707b1d1fa83cd99
$ openssl x509 -noout -modulus -in public.crt | openssl md5
4f49b61b25225abeb7542b29ae20e98c
```
If the two outputs differ like the previous example, there's a mismatch between
the certificate and key. Contact the provider of the SSL certificate for
further support.
## Using GitLab Runner with a GitLab instance configured with internal CA certificate or self-signed certificate
Besides getting the errors mentioned in
[Using an internal CA certificate with GitLab](ssl.md#using-an-internal-ca-certificate-with-gitlab),
your CI pipelines may get stuck in `Pending` status. In the runner logs you may
see the following error message:
```shell
Dec 6 02:43:17 runner-host01 gitlab-runner[15131]: #033[0;33mWARNING: Checking for jobs... failed
#033[0;m #033[0;33mrunner#033[0;m=Bfkz1fyb #033[0;33mstatus#033[0;m=couldn't execute POST against
https://gitlab.domain.tld/api/v4/jobs/request: Post https://gitlab.domain.tld/api/v4/jobs/request:
x509: certificate signed by unknown authority
```
Follow the details in [Self-signed certificates or custom Certification Authorities for GitLab Runner](https://docs.gitlab.com/runner/configuration/tls-self-signed.html).
## Mirroring a remote GitLab repository that uses a self-signed SSL certificate
When configuring a local GitLab instance to [mirror a repository](../../user/project/repository/mirror/index.md)
from a remote GitLab instance that uses a self-signed certificate, you may see
the `SSL certificate problem: self signed certificate` error message in the
user interface.
The cause of the issue can be confirmed by checking if:
- `curl` fails:
```shell
$ curl "https://gitlab.domain.tld"
curl: (60) SSL certificate problem: self signed certificate
More details here: https://curl.haxx.se/docs/sslcerts.html
```
- Testing by using the Rails console also fails:
```ruby
uri = URI.parse("https://gitlab.domain.tld")
http = Net::HTTP.new(uri.host, uri.port)
http.use_ssl = true
http.verify_mode = 1
response = http.request(Net::HTTP::Get.new(uri.request_uri))
...
Traceback (most recent call last):
1: from (irb):5
OpenSSL::SSL::SSLError (SSL_connect returned=1 errno=0 state=error: certificate verify failed (unable to get local issuer certificate))
```
To fix this problem:
- Add the self-signed certificate from the remote GitLab instance to the
`/etc/gitlab/trusted-certs` directory on the local GitLab instance, and then
run `sudo gitlab-ctl reconfigure` as per the instructions for
[installing custom public certificates](https://docs.gitlab.com/omnibus/settings/ssl.html#install-custom-public-certificates).
- If your local GitLab instance was installed using the Helm Charts, you can
[add your self-signed certificate to your GitLab instance](https://docs.gitlab.com/runner/install/kubernetes.html#providing-a-custom-certificate-for-accessing-gitlab).
You may also get another error message when trying to mirror a repository from
a remote GitLab instance that uses a self-signed certificate:
```shell
2:Fetching remote upstream failed: fatal: unable to access 'https://gitlab.domain.tld/root/test-repo/':
SSL: unable to obtain common name from peer certificate
```
In this case, the problem can be related to the certificate itself:
1. Validate that your self-signed certificate isn't missing a common name. If it
is, regenerate a valid certificate
1. Add the certificate to `/etc/gitlab/trusted-certs`.
1. Run `sudo gitlab-ctl reconfigure`.
## Unable to perform Git operations due to an internal or self-signed certificate
If your GitLab instance is using a self-signed certificate, or if the
certificate is signed by an internal certificate authority (CA), you might
experience the following errors when attempting to perform Git operations:
```shell
$ git clone https://gitlab.domain.tld/group/project.git
Cloning into 'project'...
fatal: unable to access 'https://gitlab.domain.tld/group/project.git/': SSL certificate problem: self signed certificate
```
```shell
$ git clone https://gitlab.domain.tld/group/project.git
Cloning into 'project'...
fatal: unable to access 'https://gitlab.domain.tld/group/project.git/': server certificate verification failed. CAfile: /etc/ssl/certs/ca-certificates.crt CRLfile: none
```
To fix this problem:
- If possible, use SSH remotes for all Git operations. This is considered more
secure and convenient to use.
- If you must use HTTPS remotes, you can try the following:
- Copy the self-signed certificate or the internal root CA certificate to a
local directory (for example, `~/.ssl`) and configure Git to trust your
certificate:
```shell
git config --global http.sslCAInfo ~/.ssl/gitlab.domain.tld.crt
```
- Disable SSL verification in your Git client. This is intended as a
temporary measure, as it could be considered a security risk.
```shell
git config --global http.sslVerify false
```
## SSL_connect wrong version number
A misconfiguration may result in:
- `gitlab-rails/exceptions_json.log` entries containing:
```plaintext
"exception.class":"Excon::Error::Socket","exception.message":"SSL_connect returned=1 errno=0 state=error: wrong version number (OpenSSL::SSL::SSLError)",
"exception.class":"Excon::Error::Socket","exception.message":"SSL_connect returned=1 errno=0 state=error: wrong version number (OpenSSL::SSL::SSLError)",
```
- `gitlab-workhorse/current` containing:
```plaintext
http: server gave HTTP response to HTTPS client
http: server gave HTTP response to HTTPS client
```
- `gitlab-rails/sidekiq.log` or `sidekiq/current` containing:
```plaintext
message: SSL_connect returned=1 errno=0 state=error: wrong version number (OpenSSL::SSL::SSLError)
message: SSL_connect returned=1 errno=0 state=error: wrong version number (OpenSSL::SSL::SSLError)
```
Some of these errors come from the Excon Ruby gem, and could be generated in
circumstances where GitLab is configured to initiate an HTTPS session to a
remote server that is serving only HTTP.
One scenario is that you're using [object storage](../object_storage.md), which
isn't served under HTTPS. GitLab is misconfigured and attempts a TLS handshake,
but the object storage responds with plain HTTP.
## `schannel: SEC_E_UNTRUSTED_ROOT`
If you're on Windows and get the following error:
```plaintext
Fatal: unable to access 'https://gitlab.domain.tld/group/project.git': schannel: SEC_E_UNTRUSTED_ROOT (0x80090325) - The certificate chain was issued by an authority that is not trusted."
```
You must specify that Git should use OpenSSL:
```shell
git config --system http.sslbackend openssl
```
Alternatively, you can ignore SSL verification by running:
WARNING:
Proceed with caution when [ignoring SSL](https://git-scm.com/docs/git-config#Documentation/git-config.txt-httpsslVerify)
due to the potential security issues associated with disabling this option at global level. Use this option _only_ when troubleshooting, and reinstate SSL verification immediately after.
```shell
git config --global http.sslVerify false
```