From 3511670e51036f14448ee4d38e15db46af26dfa2 Mon Sep 17 00:00:00 2001
From: Boris Zbarsky <bzbarsky@apple.com>
Date: Tue, 1 Aug 2023 15:53:24 -0400
Subject: [PATCH] Add a signature count to MTRTestKeys. (#28452)

This lets us check whether CASE resumption is happening.
---
 src/darwin/Framework/CHIPTests/TestHelpers/MTRTestKeys.h | 3 +++
 src/darwin/Framework/CHIPTests/TestHelpers/MTRTestKeys.m | 4 ++++
 2 files changed, 7 insertions(+)

diff --git a/src/darwin/Framework/CHIPTests/TestHelpers/MTRTestKeys.h b/src/darwin/Framework/CHIPTests/TestHelpers/MTRTestKeys.h
index 8741eb584e3572..9afe75266d1eed 100644
--- a/src/darwin/Framework/CHIPTests/TestHelpers/MTRTestKeys.h
+++ b/src/darwin/Framework/CHIPTests/TestHelpers/MTRTestKeys.h
@@ -25,6 +25,9 @@ NS_ASSUME_NONNULL_BEGIN
 
 @property (readonly, nonatomic) NSData * publicKeyData;
 
+// Count of how many times this keypair has been used to signMessageECDSA_DER.
+@property (readonly, nonatomic, assign) unsigned signatureCount;
+
 - (instancetype)init;
 
 @end
diff --git a/src/darwin/Framework/CHIPTests/TestHelpers/MTRTestKeys.m b/src/darwin/Framework/CHIPTests/TestHelpers/MTRTestKeys.m
index 2d073f64d11fb4..23b602e2e7208c 100644
--- a/src/darwin/Framework/CHIPTests/TestHelpers/MTRTestKeys.m
+++ b/src/darwin/Framework/CHIPTests/TestHelpers/MTRTestKeys.m
@@ -69,11 +69,15 @@ - (instancetype)init
     }
     _publicKey = SecKeyCopyPublicKey(_privateKey);
 
+    _signatureCount = 0;
+
     return self;
 }
 
 - (NSData *)signMessageECDSA_DER:(NSData *)message
 {
+    ++_signatureCount;
+
     CFErrorRef error = NULL;
     CFDataRef outData
         = SecKeyCreateSignature(_privateKey, kSecKeyAlgorithmECDSASignatureMessageX962SHA256, (__bridge CFDataRef) message, &error);