Key Generation and Secure Key Storage on STM32WL55

[nomancy]

We are working on developing a host-module that requires two-way device authentication
The controller we are planning to use is the STM32WL55 Series.

We have the following Queries.

1) Does STM32WL55 has a functionality to locally generate a certificate or a private public key pair that is not readable even by the FW itself ?

• Our goal is complete security of the device key/certificate.

2) Does STM32WL55 has a secure storage functionality where it can store externally generated certificates/keys?

• Our goal is to store keys in unreadable form but still accessible for security operations.

We need a brief explanation of how the mentioned functionality can be achieved on the STM32WL55 microcontroller.

Also please share all the relevant documents and Example code explaining the security architecture of STM32WL55

[STea · Accepted solution]

Hello @nomancy ,

1) Key management is supported by a proprietary Middleware which give ready to use services ,it is provided in KMS(key management services Middleware ) which manages key storage for cryptographic and certificates use. Refer to the description of KMS_MW for more detailed description of this Middleware .

2) The answer for your second inquiry is the Key provisioning functionality which manages provisioning and secure usage of secrets this is detailed in the UM2262 of SBSFU  appendix H.

by the way the usage that you are describing is fully covered by the SBSFU example for the STM32WB series found in the SBSFU package under STM32CubeExpansion_SBSFU_V2.6.2\Projects\P-NUCLEO WB55.Nucleo\Applications\1_Image .

Hope this answers your requests .

BR