topic Re: Read a key from secure NVM in S32K

Read a key from secure NVM

shravani — Wed, 24 Apr 2024 10:05:33 GMT

Hi, I wanted to read a key from secure NVM, is it possible to read back a key? I want to use this key further in my application. I checked the RTD firmware there is only one service for exporting key from RAM. Also, in the Firmware reference manual of HSE it is mentioned that SHE NVM keys cannot be exported. How could I use stored key in my application?

Please check below details.

1) Microcontroller: S32K312_100MQFP

2) IDE: S32DS 3.5

3) SDK Version: PlatformSDK_S32K3_2022_03

Re: Read a key from secure NVM

davidtosenovjan — Thu, 25 Apr 2024 11:56:50 GMT

It is stated in section
6.3.6.2 SHE key update policies

"When RAM_KEY is updated with the SHE key update protocol, it cannot be exported, until it is updated in plain via the key import service or via the SHE plain key update."

"NVM SHE keys cannot be exported." as you already screenshot.

Re: Read a key from secure NVM

shravani — Thu, 25 Apr 2024 12:04:23 GMT

Hi, I want to apply AES 128 encryption on the key which is stored in the secure NVM. How could I achieve this?

Re: Read a key from secure NVM

davidtosenovjan — Tue, 30 Apr 2024 08:13:11 GMT

It cannot be done as a key stored in the secure NVM cannot be exported.

Re: Read a key from secure NVM

HaiHoangSoftware — Wed, 19 Mar 2025 09:01:20 GMT

Hi,

I can not read AES key after import. I'm using NVM key handle.

Importing key is success. But export key is failed.

Is there anyone know how to solve this issue?

Thanks a lot.

Here is my implementation:

hseKeyInfo_t keyInfo = {0};
uint8_t sharedSecret[448];
uint16_t sharedSecretLen = 32;
void testFunction(void) {
hseSrvResponse_t hseResponse = HSE_SRV_RSP_GENERAL_ERROR;
hseResponse = ExportPlainSymKeyReq( EXAMPLE_NVM_KEY_HANDLE,
&keyInfo, sharedSecret, &sharedSecretLen);
}