When nrf9160 is https_client, can I connect to the server without validating the server certificate?

[OYAMA YUKIO]

Hi all,

In the nRF9160 https_Client sample, I was able to connect to the server by provisioning a server-matched root certificate to the nRF9160.

Can I connect to an https server without provisioning a certificate on the NRF9160 when security is not a concern?

When not provisioning a certificate to the nRF9160, it seems to be failing. However, I think I can communicate encrypted with the https server using only the public key provided by the server.

Is my idea wrong?

Again, I'm not going to discuss security. I would like to know if there is a way to communicate with the https server despite the lack of a certificate on the client side.

For example, I think the -k option in Curl is actually doing that.

If that is possible, please tell me the procedure in nRF9160. Thank you.

HW:nRF9160DK

FW:modem v1.3.1

   SDK v1.9.1

Best Regards,

Yukio Oyama

[OYAMA YUKIO]

Hi Øyvind-san,

I tried according to your advice.

Skipping "cert_provision()" will result in a certificate error.

In "tls_setup()", "socket()" needs any TLS setting and I don't know how to skip it.

My changes may not be correct. Please tell me specifically where to change in the code.

Best Regards,

Yukio Oyama

[OYAMA YUKIO]

Hi Øyvind-san,

I referred to the thread below.

https://devzone.nordicsemi.com/f/nordic-q-a/63282/is-it-possible-to-skip-certificate-validation-in-https

I changed "verify" in tls_setup () to NONE.

verify = NONE; //Changed it from REQUIRED

I was able to communicate using "https_client" sample without using a root certificate. Thank you.

Best Regards,

Yukio Oyama

[Øyvind]

Hello Yukio-san, 

my apologies for the late reply.

Øyvind said:

Have you tried removing the functions regarding TLS and certificates? The sample is designed to connect using a x509 certificate. 

Sorry, you also need to replace TLS_PEER_VERIFY with TLS_PEER_VERIFY_NONE on line 117:

err = setsockopt(fd, SOL_TLS, TLS_PEER_VERIFY_NONE, &verify, sizeof(verify));

This will allowed me to connect to the example server without getting "Failed to setup peer verification, err 109"

[OYAMA YUKIO]

Hi Øyvind-san,

Thank you for your advice.

I followed your advice and changed TLS_PEER_VERIFY to TLS_PEER_VERIFY_NONE.

For now, I don't feel any difference from changing only verify. But I will change both verify and TLS_PEER_VERIFY_NONE and proceed with the work. Thank you.

Best Regards,

Yukio Oyama