[Nearby] Add copy constructor to private certificate class

A NearbySharePrivateCertificate copy constructor will be necessary for
testing.

Change-Id: Ib82c7be478b6a27218e7fad13832da74db285fba
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2330049
Commit-Queue: Josh Nohle <nohle@chromium.org>
Commit-Queue: James Vecore <vecore@google.com>
Auto-Submit: Josh Nohle <nohle@chromium.org>
Reviewed-by: James Vecore <vecore@google.com>
Cr-Commit-Position: refs/heads/master@{#793658}

chrome/browser/nearby_sharing/certificates/nearby_share_private_certificate.cc

@@ -176,7 +176,35 @@ NearbySharePrivateCertificate::NearbySharePrivateCertificate(
 }
 
 NearbySharePrivateCertificate::NearbySharePrivateCertificate(
-    NearbySharePrivateCertificate&&) = default;
+    const NearbySharePrivateCertificate& other) {
+  *this = other;
+}
+
+NearbySharePrivateCertificate& NearbySharePrivateCertificate::operator=(
+    const NearbySharePrivateCertificate& other) {
+  if (this == &other)
+    return *this;
+
+  visibility_ = other.visibility_;
+  not_before_ = other.not_before_;
+  not_after_ = other.not_after_;
+  key_pair_ = other.key_pair_->Copy();
+  secret_key_ = crypto::SymmetricKey::Import(
+      crypto::SymmetricKey::Algorithm::AES, other.secret_key_->key());
+  metadata_encryption_key_ = other.metadata_encryption_key_;
+  id_ = other.id_;
+  unencrypted_metadata_ = other.unencrypted_metadata_;
+  consumed_salts_ = other.consumed_salts_;
+  next_salts_for_testing_ = other.next_salts_for_testing_;
+  offset_for_testing_ = other.offset_for_testing_;
+  return *this;
+}
+
+NearbySharePrivateCertificate::NearbySharePrivateCertificate(
+    NearbySharePrivateCertificate&& other) = default;
+
+NearbySharePrivateCertificate& NearbySharePrivateCertificate::operator=(
+    NearbySharePrivateCertificate&& other) = default;
 
 NearbySharePrivateCertificate::~NearbySharePrivateCertificate() = default;
 

chrome/browser/nearby_sharing/certificates/nearby_share_private_certificate.h

@@ -58,7 +58,12 @@ class NearbySharePrivateCertificate {
       nearbyshare::proto::EncryptedMetadata unencrypted_metadata,
       std::set<std::vector<uint8_t>> consumed_salts);
 
-  NearbySharePrivateCertificate(NearbySharePrivateCertificate&&);
+  NearbySharePrivateCertificate(const NearbySharePrivateCertificate& other);
+  NearbySharePrivateCertificate& operator=(
+      const NearbySharePrivateCertificate& other);
+  NearbySharePrivateCertificate(NearbySharePrivateCertificate&& other);
+  NearbySharePrivateCertificate& operator=(
+      NearbySharePrivateCertificate&& other);
 
   virtual ~NearbySharePrivateCertificate();