7 File System

The RNWF02 provides an internal secured storage for storing following types of certificates and keys to use with the Transport Layer Security (TLS).

  • x509 root certificates
  • Client/Device certificates
  • Private keys

The secured certificate store is of 60 KB in size and it is write and erase only storage space. The certificates and keys flashed in this memory is only readable through the device firmware.

The certificate store can be accessed through the AT commands. For more details on AT commands, refer to the 9.1 AT Commands

The manual certificate/key flashing would need a serial terminal application with X-Modem/Y-Modem file transfer support. In order to simplify this process the firmware release package includes a python based utility which can Flash these files through a simple CLI

The utility also support Send To option on Windows operating system where these files can be flashed into RNWF02 device through the right click options.

By default the RNWF02 modules include following Root Certificates in the certificate store for easier could connectivity.
Table 7-1. Pre-packaged TLS Root Certificates
Issuer Filename Expiry Public Key Signature Alg. Notes
Amazon Root CA 1 AmazonRootCA1.der 17 January 2038 01:00:00 RSA (2048 bits) SHA256RSA AWS Cloud
Baltimore CyberTrust Root BaltimoreCyberTrustRoot.der 13 May 2025 00:59:00 RSA (2048 bits) SHA1RSA Azure Cloud

DigiCert High Assurance EV Root CA

 DigiCert.der 10 November 2031 01:00:00 RSA (2048 bits) SHA1RSA —
DigiCert Global Root G2 DigiCertGlobalRootG2.crt 15 January 2038 13:00:00 RSA (2048 bits) SHA256RSA Azure Cloud

DigiCert High Assurance EV Root CA

 DigiCertSHA2.der 22 October 2028 13:00:00 RSA (2048 bits) SHA256RSA —

Entrust Root Certification Authority

 EnTrust.der 27 November 2026 21:53:42 RSA (2048 bits) SHA1RSA —
GlobalSign Root CA GlobalSignRoot.der 28 January 2028 13:00:00 RSA (2048 bits) SHA1RSA —

Internet Security Research Group Root X1

 isrgrootx1.der 04 June 2035 12:04:38 RSA (4096 bits) SHA256RSA LetsEncrypt
QuoVadis Root CA 2 QuoVadis_Root.der 24 November 2031 19:23:33 RSA (4096 bits) SHA1RSA —

VeriSign Class 3 Primary Certification Authority

 VeriSign.der 17 July 2036 00:59:59 RSA (2048 bits) SHA1RSA —

Setup Details – The certificate and key utility uses the AT command interface serial port of the RNWF02 module. The PC companion mode of the setup must be used to use the certificate and key utility.