From 79438881ec2216435baf1857ad6ffdc4fcef2bcb Mon Sep 17 00:00:00 2001
From: Rohan Sahay <103027015+rosahay-silabs@users.noreply.github.com>
Date: Thu, 16 Jan 2025 16:42:45 +0530
Subject: [PATCH] Refactor device attestation key handling in
 ProvisionStorageFlash.cpp

---
 .../platform/silabs/provision/ProvisionStorageFlash.cpp  | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/examples/platform/silabs/provision/ProvisionStorageFlash.cpp b/examples/platform/silabs/provision/ProvisionStorageFlash.cpp
index fae1b5c713b910..b7642150e194dd 100644
--- a/examples/platform/silabs/provision/ProvisionStorageFlash.cpp
+++ b/examples/platform/silabs/provision/ProvisionStorageFlash.cpp
@@ -649,7 +649,6 @@ CHIP_ERROR Storage::GetDeviceAttestationCSR(uint16_t vid, uint16_t pid, const Ch
 
 CHIP_ERROR Storage::SignWithDeviceAttestationKey(const ByteSpan & message, MutableByteSpan & signature)
 {
-    AttestationKey key;
     uint8_t temp[kDeviceAttestationKeySizeMax] = { 0 };
     size_t size                                = 0;
     CHIP_ERROR err                             = Flash::Get(Parameters::ID::kDacKey, temp, sizeof(temp), size);
@@ -661,8 +660,16 @@ CHIP_ERROR Storage::SignWithDeviceAttestationKey(const ByteSpan & message, Mutab
     }
 #endif // CHIP_DEVICE_CONFIG_ENABLE_EXAMPLE_CREDENTIALS
     ReturnErrorOnFailure(err);
+#if (defined(SLI_SI91X_MCU_INTERFACE) && SLI_SI91X_MCU_INTERFACE)
+    uint8_t key_buffer[kDeviceAttestationKeySizeMax] = { 0 };
+    MutableByteSpan private_key(key_buffer);
+    AttestationKey::Unwrap(temp, size, private_key);
+    return AttestationKey::SignMessageWithKey((const uint8_t *) key_buffer, message, signature);
+#else
+    AttestationKey key;
     ReturnErrorOnFailure(key.Import(temp, size));
     return key.SignMessage(message, signature);
+#endif // SLI_SI91X_MCU_INTERFACE
 }
 
 //