[server] Allow setting platform-specific session keystore.

Allow setting session keystore by platform. If any keystore is not
set, assign the default one.

Signed-off-by: Arkadiusz Balys <arkadiusz.balys@nordicsemi.no>

Author: ArekBalysNordic

src/app/server/Server.cpp

@@ -791,7 +791,7 @@ SimpleSessionResumptionStorage CommonCaseDeviceServerInitParams::sSessionResumpt
 app::SimpleSubscriptionResumptionStorage CommonCaseDeviceServerInitParams::sSubscriptionResumptionStorage;
 #endif
 app::DefaultAclStorage CommonCaseDeviceServerInitParams::sAclStorage;
-Crypto::DefaultSessionKeystore CommonCaseDeviceServerInitParams::sSessionKeystore;
+Crypto::DefaultSessionKeystore CommonCaseDeviceServerInitParams::sDefaultSessionKeystore;
 #if CHIP_CONFIG_ENABLE_ICD_CIP
 app::DefaultICDCheckInBackOffStrategy CommonCaseDeviceServerInitParams::sDefaultICDCheckInBackOffStrategy;
 #endif

src/app/server/Server.h

@@ -273,7 +273,10 @@ struct CommonCaseDeviceServerInitParams : public ServerInitParams
         }
 
         // Session Keystore injection
-        this->sessionKeystore = &sSessionKeystore;
+        if (this->sessionKeystore == nullptr)
+        {
+            this->sessionKeystore = &sDefaultSessionKeystore;
+        }
 
         // Group Data provider injection
         sGroupDataProvider.SetStorageDelegate(this->persistentStorageDelegate);
@@ -327,7 +330,7 @@ struct CommonCaseDeviceServerInitParams : public ServerInitParams
     static app::SimpleSubscriptionResumptionStorage sSubscriptionResumptionStorage;
 #endif
     static app::DefaultAclStorage sAclStorage;
-    static Crypto::DefaultSessionKeystore sSessionKeystore;
+    static Crypto::DefaultSessionKeystore sDefaultSessionKeystore;
 #if CHIP_CONFIG_ENABLE_ICD_CIP
     static app::DefaultICDCheckInBackOffStrategy sDefaultICDCheckInBackOffStrategy;
 #endif

src/crypto/crypto.gni

@@ -28,5 +28,5 @@ assert(
     !chip_external_mbedtls || chip_crypto == "mbedtls" || chip_crypto == "psa",
     "Use of external mbedtls requires the mbedtls or psa crypto impl")
 
-assert(!chip_crypto_psa_spake2p || chip_crypto == "psa",
-       "Use of psa spake2+ requires the psa crypto impl")
+assert(!chip_crypto_psa_spake2p || chip_crypto == "psa" || chip_crypto == "platform",
+       "Use of psa spake2+ requires the psa crypto or platform implementation")