3.1.2 Generating the CA Certificate

Perform the following steps to generate the CA certificate:

  1. Generate the CA key using the openssl genrsa -out winc_root.key 2048 command.
  2. Generate the CA certificate using the CA key and using the openssl req -new -x509 -days 365 -key winc_root.key -out winc_root.crt command.
  3. The ATWINC root certificate downloader accepts the certificates in .der format only. Therefore, convert the CA certificate to .der format using the openssl x509 -outform der -in winc_root.crt -out winc_root.cer command.
Note:
  1. To flash the root certificate onto ATWINC1500 Flash, save the winc_root.cer file in the root certificate downloader folder \firmware_update_project\firmware\Tools\root_certificate_downloader\binary in the firmware update project and perform the firmware update.
  2. If the certificate upload fails with “(ERROR) Root Certificate Flash is Full,” then, the ATWINC memory for certificates is full and the user must upload the certificate after removing one or more certificates from src\firmware\Tools\root_certificate_downloader\binary folder.
  3. For more details, refer to the WINC1500/WINC3400 Integrated Serial Flash Memory Download Procedure (DS00002378) document.