psa_generate_key failed! with Error: -134

[vipin das]

Hi nordic team, 

I am working on an application which uses crypto cell feature, wifi capability of nrf7002DK, mbedTLS etc. I proceeded my development after individually verifying each features on nrf7002dk (crypto cell, wifi, mbedTLS etc). 

My current problem is that, psa_generate_key() failed to generate key and returns error code of -134. This is happening only if I integrate my complete application(crypto cell, wifi, mbedtls etc). If I run crypto cell specific changes alone it works and if I run  along with wifi + mbedTLS changes it fails. I am not sure what causes this problem. 

Just sharing my prj.conf below. 

With below configuration crypto cell feature for private key generation is working as expected. 

#
#   Application project specific configuration
#
CONFIG_SOC_SERIES_NRF53X=y
CONFIG_SOC_NRF5340_CPUAPP_QKAA=y
# Target memory specific options
CONFIG_HW_UNIQUE_KEY=y
CONFIG_HW_UNIQUE_KEY_RANDOM=y
CONFIG_PM_SINGLE_IMAGE=y
CONFIG_MPU_ALLOW_FLASH_WRITE=y
CONFIG_RESET_ON_FATAL_ERROR=y
CONFIG_REBOOT=y
CONFIG_NRF_SECURITY=y
CONFIG_FPU=y
CONFIG_FP_HARDABI=y
CONFIG_KERNEL_MEM_POOL=y
# System settings
CONFIG_NEWLIB_LIBC=y
CONFIG_NEWLIB_LIBC_NANO=n

# Enable nordic security backend and PSA APIs
CONFIG_MBEDTLS_PSA_CRYPTO_C=y
CONFIG_MBEDTLS_ENABLE_HEAP=y

CONFIG_TRUSTED_EXECUTION_SECURE=y
CONFIG_BUILD_WITH_TFM=n

# For hardware crypto accelerator
CONFIG_PSA_CRYPTO_DRIVER_OBERON=n
CONFIG_PSA_CRYPTO_DRIVER_CC3XX=y

# Memories
CONFIG_MAIN_STACK_SIZE=16384
# Below section is the primary contributor to SRAM and is currently
# tuned for performance, but this will be revisited in the future.
CONFIG_HEAP_MEM_POOL_SIZE=153600
CONFIG_MBEDTLS_HEAP_SIZE=120000

# Enable logging using RTT and UART
CONFIG_CONSOLE=y
CONFIG_LOG=y
CONFIG_LOG_BACKEND_UART=y
CONFIG_LOG_BUFFER_SIZE=15360

# General
CONFIG_POSIX_CLOCK=y
CONFIG_POSIX_MAX_FDS=8
CONFIG_HW_STACK_PROTECTION=y
CONFIG_HW_ID_LIBRARY_SOURCE_NET_MAC=y
CONFIG_DK_LIBRARY=y
CONFIG_PM=y

# Kernel options
CONFIG_ENTROPY_GENERATOR=y

# Memory support
CONFIG_FLASH=y
CONFIG_FLASH_PAGE_LAYOUT=y
CONFIG_FLASH_MAP=y
CONFIG_NVS=y
CONFIG_SETTINGS=y
CONFIG_SETTINGS_NVS=y

But when I add below configuration for enabling wifi & network, spa_generate_key fails with -134.

# WiFi driver 
CONFIG_WIFI=y
CONFIG_WIFI_NRF700X=y
# WPA supplicant
CONFIG_WPA_SUPP=y

# NET sockets
CONFIG_NETWORKING=y
CONFIG_NET_SOCKETS=y
CONFIG_NET_SOCKETS_POSIX_NAMES=y
CONFIG_NET_SOCKETS_POLL_MAX=8
CONFIG_NET_L2_ETHERNET=y
CONFIG_NET_IPV4=y
CONFIG_NET_TCP=y
CONFIG_NET_SOCKETS_OFFLOAD=n
CONFIG_NET_NATIVE=y
CONFIG_NET_DHCPV4=y
CONFIG_NET_CONTEXT_SNDTIMEO=y

CONFIG_NET_TCP_ISN_RFC6528=y
CONFIG_NET_MGMT_EVENT_INFO=y
CONFIG_NET_IF_UNICAST_IPV4_ADDR_COUNT=1
CONFIG_NET_MAX_CONTEXTS=5
CONFIG_NET_CONTEXT_SYNC_RECV=y

# Network address config
CONFIG_NET_CONFIG_SETTINGS=y
CONFIG_NET_CONFIG_NEED_IPV4=y
CONFIG_NET_CONFIG_MY_IPV4_ADDR="192.168.1.99"
CONFIG_NET_CONFIG_MY_IPV4_NETMASK="255.255.255.0"
CONFIG_NET_CONFIG_MY_IPV4_GW="192.168.1.1"

# Server IPV4/IPV6 address config
#Mainnet.Incubed
CONFIG_NET_CONFIG_PEER_IPV4_ADDR="167.86.94.248"

Can some one please tell me what should be the problem with key_generation and wifi network configuration. 

Thanks 

Vipin Das

[Kenneth]

Hello,

-134 means PSA_ERROR_NOT_SUPPORTED.

Unfortunately, your issue is likely related to known issue:
Zephyr bus fault when using PSA crypto with CC310 and Openthread L2 layer 
PSA crypto features not enabled when CONFIG_MBEDTLS_LEGACY_CRYPTO_C is enabled 

You may try the patch mentioned in the thread, but I can check internally if there is any news on this.

Best regards,
Kenneth

[vipin das]

Hi Kenneth, 

I looked into the threads mentioned but I don't think that the suggestions mentioned there helps to solve my issues as I don't have open thread feature in my application. I am working on integrating nrf security sub system module(crypto cell ) application and transport application(wifi, tcp/tls) to develop a new usecase application which securely communicate with remote network.

NCS Version: nrf-connect-sdk-v2.2.99-dev3

Zephyr SDK Version: 0.15.2

Please let me know if you get any clue on this issue. My prj.conf is added here. 

#
#   Application project specific configuration
#
CONFIG_SOC_SERIES_NRF53X=y
CONFIG_SOC_NRF5340_CPUAPP_QKAA=y

# Target memory specific options
CONFIG_HW_UNIQUE_KEY=y
CONFIG_HW_UNIQUE_KEY_RANDOM=y
CONFIG_PM_SINGLE_IMAGE=y
CONFIG_MPU_ALLOW_FLASH_WRITE=y
CONFIG_RESET_ON_FATAL_ERROR=y
CONFIG_REBOOT=y
CONFIG_FPU=y
CONFIG_FP_HARDABI=y
CONFIG_KERNEL_MEM_POOL=y
CONFIG_INIT_STACKS=y

# System settings
CONFIG_NEWLIB_LIBC=y
CONFIG_NEWLIB_LIBC_NANO=n

# Device security specific configs
CONFIG_NRF_SECURITY=y
CONFIG_NRF_SECURITY_ADVANCED=y
CONFIG_TRUSTED_EXECUTION_SECURE=y
CONFIG_BUILD_WITH_TFM=n
CONFIG_TFM_PROFILE_TYPE_NOT_SET=y

# For hardware crypto accelerator
CONFIG_PSA_CRYPTO_DRIVER_OBERON=n
CONFIG_PSA_CRYPTO_DRIVER_CC3XX=y

# Enable nordic security backend and PSA APIs
CONFIG_MBEDTLS_PSA_CRYPTO_C=y


# General
CONFIG_POSIX_CLOCK=y
CONFIG_POSIX_MAX_FDS=8
CONFIG_HW_STACK_PROTECTION=y
CONFIG_HW_ID_LIBRARY_SOURCE_NET_MAC=y
CONFIG_DK_LIBRARY=y
CONFIG_PM=y
CONFIG_FPU=y

# System settings
CONFIG_NEWLIB_LIBC=y
CONFIG_NEWLIB_LIBC_NANO=n

# Kernel options
CONFIG_ENTROPY_GENERATOR=y

# Memories
CONFIG_MAIN_STACK_SIZE=4096
CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=4096
CONFIG_NET_TX_STACK_SIZE=4096
CONFIG_NET_RX_STACK_SIZE=4096
CONFIG_NET_TCP_WORKQ_STACK_SIZE=4096
CONFIG_NET_MGMT_EVENT_STACK_SIZE=4096
CONFIG_LOG_BUFFER_SIZE=4096
# Below section is the primary contributor to SRAM and is currently
# tuned for performance, but this will be revisited in the future.
CONFIG_HEAP_MEM_POOL_SIZE=153600
CONFIG_NET_BUF_RX_COUNT=16
CONFIG_NET_BUF_TX_COUNT=16
CONFIG_NET_BUF_DATA_SIZE=128
CONFIG_NET_TC_TX_COUNT=0
CONFIG_NET_PKT_RX_COUNT=8
CONFIG_NET_PKT_TX_COUNT=8

#Socket settings
CONFIG_NET_SOCKETS_SOCKOPT_TLS=y

# Native network stack
CONFIG_NRF_SECURITY=y
CONFIG_MBEDTLS=y
CONFIG_MBEDTLS_BUILTIN=y
CONFIG_MBEDTLS_ENABLE_HEAP=y
CONFIG_MBEDTLS_HEAP_SIZE=120000
CONFIG_MBEDTLS_SSL_MAX_CONTENT_LEN=16384
CONFIG_MBEDTLS_KEY_EXCHANGE_RSA_ENABLED=y
CONFIG_MBEDTLS_MAC_SHA256_ENABLED=y

# PSA
CONFIG_PSA_CRYPTO_DRIVER_CC3XX=y

# NET sockets
CONFIG_NETWORKING=y
CONFIG_NET_SOCKETS=y
CONFIG_NET_SOCKETS_POSIX_NAMES=y
CONFIG_NET_SOCKETS_POLL_MAX=8
CONFIG_NET_L2_ETHERNET=y
CONFIG_NET_IPV4=y
CONFIG_NET_TCP=y
CONFIG_NET_SOCKETS_OFFLOAD=n
CONFIG_NET_NATIVE=y
CONFIG_NET_DHCPV4=y
CONFIG_NET_CONTEXT_SNDTIMEO=y

CONFIG_NET_TCP_ISN_RFC6528=y
CONFIG_NET_MGMT_EVENT_INFO=y
CONFIG_NET_IF_UNICAST_IPV4_ADDR_COUNT=1
CONFIG_NET_MAX_CONTEXTS=5
CONFIG_NET_CONTEXT_SYNC_RECV=y
CONFIG_INIT_STACKS=y

# DNS
CONFIG_DNS_RESOLVER=y

# Debugging
CONFIG_STACK_SENTINEL=y
CONFIG_DEBUG_COREDUMP=y
CONFIG_DEBUG_COREDUMP_BACKEND_LOGGING=y
CONFIG_DEBUG_COREDUMP_MEMORY_DUMP_MIN=y
CONFIG_SHELL_CMDS_RESIZE=n

# Logging
CONFIG_LOG=y
CONFIG_NET_LOG=y
CONFIG_NET_TCP_LOG_LEVEL_DBG=n
CONFIG_NET_SOCKETS_LOG_LEVEL_DBG=n
CONFIG_NET_CONN_LOG_LEVEL_DBG=n
CONFIG_NET_CONTEXT_LOG_LEVEL_DBG=n
CONFIG_NET_HTTP_LOG_LEVEL_DBG=n
CONFIG_WIFI_LOG_LEVEL_ERR=n
CONFIG_WPA_SUPP_LOG_LEVEL_ERR=n

# Network address config
CONFIG_NET_CONFIG_SETTINGS=y
CONFIG_NET_CONFIG_NEED_IPV4=y
CONFIG_NET_CONFIG_MY_IPV4_ADDR="192.168.1.99"
CONFIG_NET_CONFIG_MY_IPV4_NETMASK="255.255.255.0"
CONFIG_NET_CONFIG_MY_IPV4_GW="192.168.1.1"

# Server IPV4/IPV6 address config
#Mainnet.Incubed
CONFIG_NET_CONFIG_PEER_IPV4_ADDR="167.86.94.248"

# HTTP
CONFIG_HTTP_CLIENT=y

# WiFi driver 
CONFIG_WIFI=y
CONFIG_WIFI_NRF700X=y
CONFIG_FLASH=y
CONFIG_FLASH_PAGE_LAYOUT=y
CONFIG_FLASH_MAP=y
CONFIG_NVS=y
CONFIG_SETTINGS=y
CONFIG_SETTINGS_NVS=y

# WPA supplicant
CONFIG_WPA_SUPP=y

 Regards

Vipin Das

[vipin das]

Thanks for the detailed information. I completely got your point and agree with you. 

We are focussing on developing secure product. But right now, we wanted to utilise the key derivation and management feature and try to communicate securely with remote server/devices. 

As I mentioned, we already have our crypto portion working and wifi portion working. Only the wpa_supplicant one is making the psa key derivation to fail. 

Let me ask you one thing, is there any way I can connect to wifi with disabling wpa_supplicant?. I mean wifi connect using part terminal etc. That is also fine for time being to progress my further development. 

Thanks 

Vipin Das

[Einar Thorsrud]

Hi Vipin,

The Wi-Fi stack depends on wpa_supplicant for other tasks as well (see Supplicant), so I think it will be difficult to do much useful - even with open networks - without wpa_supplicant. (You can do some things without it though, like scanning).

[vipin das]

Hi Einar, 

So it is not at all possible to have wifi connection without wpa_supplicant right.

In that case is there any other crypto api options I can use to generate key pairs other than  psa_generate_key() and store the private key securely in KMU. But those api shouldn't fail with wpa_supplicant. If you have any suggestions please share the information.

Regards

Vipin Das

[Einar Thorsrud]

Hi,

I don't have a good solution at this point as that needs more work, but you should be able to use the Legacy crypto support. One example of that with KMU is the Random hardware unique key sample. This is not what I would recommend long term, but if you need something right now, it is a possibility.

[vipin das]

Thanks Einar for your support. 

Right now I am not closing this topic, as I would be waiting for the proper fix for compatibility issue with wpa_supplicant with the PSA crypto libraries. 

Hope you will update me with any news on the fix. 

Thanks once again.

Regards

Vipin Das