Openssl : error "self signed certificate in certificate chain"

The solution for the error is to add this line at the top of the code:

process.env.NODE_TLS_REJECT_UNAUTHORIZED = "0";

If you're running Charles and trying to build a docker container then you'll most likely get this error.

Make sure to disable Charles (macos) proxy under proxy -> macOS proxy

Charles is an

HTTP proxy / HTTP monitor / Reverse Proxy that enables a developer to view all of the HTTP and SSL / HTTPS traffic between their machine and the Internet.

So anything similar may cause the same issue.

Here is one-liner to verify certificate to be signed by specific CA:

openssl verify -verbose -x509_strict -CAfile ca.pem certificate.pem

This doesn't require to install CA anywhere.

See How does an SSL certificate chain bundle work? for details and correct certificate chain handling.

You have a certificate which is self-signed, so it's non-trusted by default, that's why OpenSSL complains. This warning is actually a good thing, because this scenario might also rise due to a man-in-the-middle attack.

To solve this, you'll need to install it as a trusted server. If it's signed by a non-trusted CA, you'll have to install that CA's certificate as well.

Have a look at this link about installing self-signed certificates.