mbedTLS - Sign an already done certificate request from device private key?

I have an already done certificate request with out a signature, only 256 x 0’s in the end, how do I make a signature for writing in the end of this certificate. Is this possible with out passing the certificate and rewriting a new certificate.

HI Christian,
I am not sure I understand your question.
When you generate a certificate request (CSR), using the API, the generated cesrtificate request is already signed. How do you get it unsigned?
Have you read this article?

Note that a certificate request is not a certificate, so I don’t understand what you mean with your last sentence.

Please explain your use case

Mbed TLS Support

I have solver the problem, I’m receiving a certificate request with out pbkey and signature, I put in the key and calculate the sha256 signature and send back. The problem was how much from the certificate request I had to include in the calculation but I got it. Thanks.