Change ClientProofSource::GetCertAndKey() to return shared_ptr<CertAndKey> instead of a raw pointer of CertAndKey.

This is to future prevent the caller from accessing the return value after the proof source implementation has destroyed it.

Interface change only.

PiperOrigin-RevId: 615222541

quiche/quic/core/crypto/client_proof_source.cc

diff --git a/quiche/quic/core/crypto/client_proof_source.cc b/quiche/quic/core/crypto/client_proof_source.cc
index 2d477db..94c6490 100644
--- a/quiche/quic/core/crypto/client_proof_source.cc
+++ b/quiche/quic/core/crypto/client_proof_source.cc
@@ -26,9 +26,9 @@
   return true;
 }
 
-const ClientProofSource::CertAndKey* DefaultClientProofSource::GetCertAndKey(
-    absl::string_view hostname) const {
-  if (const CertAndKey* const result = LookupExact(hostname);
+std::shared_ptr<const ClientProofSource::CertAndKey>
+DefaultClientProofSource::GetCertAndKey(absl::string_view hostname) const {
+  if (std::shared_ptr<const CertAndKey> result = LookupExact(hostname);
       result || hostname == "*") {
     return result;
   }
@@ -39,7 +39,7 @@
     auto dot_pos = hostname.find('.');
     if (dot_pos != std::string::npos) {
       std::string wildcard = absl::StrCat("*", hostname.substr(dot_pos));
-      const CertAndKey* const result = LookupExact(wildcard);
+      std::shared_ptr<const CertAndKey> result = LookupExact(wildcard);
       if (result != nullptr) {
         return result;
       }
@@ -50,13 +50,13 @@
   return LookupExact("*");
 }
 
-const ClientProofSource::CertAndKey* DefaultClientProofSource::LookupExact(
-    absl::string_view map_key) const {
+std::shared_ptr<const ClientProofSource::CertAndKey>
+DefaultClientProofSource::LookupExact(absl::string_view map_key) const {
   const auto it = cert_and_keys_.find(map_key);
   QUIC_DVLOG(1) << "LookupExact(" << map_key
                 << ") found:" << (it != cert_and_keys_.end());
   if (it != cert_and_keys_.end()) {
-    return it->second.get();
+    return it->second;
   }
   return nullptr;
 }

quiche/quic/core/crypto/client_proof_source.h

diff --git a/quiche/quic/core/crypto/client_proof_source.h b/quiche/quic/core/crypto/client_proof_source.h
index f2ceb12..589d1be 100644
--- a/quiche/quic/core/crypto/client_proof_source.h
+++ b/quiche/quic/core/crypto/client_proof_source.h
@@ -37,7 +37,7 @@
   // |server_hostname| is typically a full domain name(www.foo.com), but it
   // could also be a wildcard domain(*.foo.com), or a "*" which will return the
   // default cert.
-  virtual const CertAndKey* GetCertAndKey(
+  virtual std::shared_ptr<const CertAndKey> GetCertAndKey(
       absl::string_view server_hostname) const = 0;
 };
 
@@ -58,10 +58,12 @@
                      CertificatePrivateKey private_key);
 
   // ClientProofSource implementation
-  const CertAndKey* GetCertAndKey(absl::string_view hostname) const override;
+  std::shared_ptr<const CertAndKey> GetCertAndKey(
+      absl::string_view hostname) const override;
 
  private:
-  const CertAndKey* LookupExact(absl::string_view map_key) const;
+  std::shared_ptr<const CertAndKey> LookupExact(
+      absl::string_view map_key) const;
   absl::flat_hash_map<std::string, std::shared_ptr<CertAndKey>> cert_and_keys_;
 };
 

quiche/quic/core/crypto/client_proof_source_test.cc

diff --git a/quiche/quic/core/crypto/client_proof_source_test.cc b/quiche/quic/core/crypto/client_proof_source_test.cc
index 0104ef3..36b9dff 100644
--- a/quiche/quic/core/crypto/client_proof_source_test.cc
+++ b/quiche/quic/core/crypto/client_proof_source_test.cc
@@ -56,7 +56,7 @@
 #define VERIFY_CERT_AND_KEY_MATCHES(lhs, rhs) \
   do {                                        \
     SCOPED_TRACE(testing::Message());         \
-    VerifyCertAndKeyMatches(lhs, rhs);        \
+    VerifyCertAndKeyMatches(lhs.get(), rhs);  \
   } while (0)
 
 void VerifyCertAndKeyMatches(const ClientProofSource::CertAndKey* lhs,

quiche/quic/core/tls_client_handshaker.cc

diff --git a/quiche/quic/core/tls_client_handshaker.cc b/quiche/quic/core/tls_client_handshaker.cc
index 30831e7..6fff29d 100644
--- a/quiche/quic/core/tls_client_handshaker.cc
+++ b/quiche/quic/core/tls_client_handshaker.cc
@@ -44,7 +44,7 @@
                           crypto_config->tls_signature_algorithms()->c_str());
   }
   if (crypto_config->proof_source() != nullptr) {
-    const ClientProofSource::CertAndKey* cert_and_key =
+    std::shared_ptr<const ClientProofSource::CertAndKey> cert_and_key =
         crypto_config->proof_source()->GetCertAndKey(server_id.host());
     if (cert_and_key != nullptr) {
       QUIC_DVLOG(1) << "Setting client cert and key for " << server_id.host();