Error out if the default proof provider is unavailable

This happens on open source QUICHE builds.

PiperOrigin-RevId: 846396937

quiche/quic/masque/masque_client_bin.cc

diff --git a/quiche/quic/masque/masque_client_bin.cc b/quiche/quic/masque/masque_client_bin.cc
index c7a4b3d..0dfc958 100644
--- a/quiche/quic/masque/masque_client_bin.cc
+++ b/quiche/quic/masque/masque_client_bin.cc
@@ -470,6 +470,12 @@
         proof_verifier = std::make_unique<FakeProofVerifier>();
       } else {
         proof_verifier = CreateDefaultProofVerifier(host);
+        if (!proof_verifier) {
+          QUICHE_LOG(ERROR)
+              << "The default proof verifier is not supported. Pass "
+                 "in --disable_certificate_verification.";
+          return 1;
+        }
       }
 
       std::unique_ptr<ClientProofSource> proof_source;

quiche/quic/masque/masque_client_tools.cc

diff --git a/quiche/quic/masque/masque_client_tools.cc b/quiche/quic/masque/masque_client_tools.cc
index 74ec2ed..5210e80 100644
--- a/quiche/quic/masque/masque_client_tools.cc
+++ b/quiche/quic/masque/masque_client_tools.cc
@@ -84,6 +84,11 @@
     proof_verifier = std::make_unique<FakeProofVerifier>();
   } else {
     proof_verifier = CreateDefaultProofVerifier(url.host());
+    if (!proof_verifier) {
+      QUICHE_LOG(ERROR) << "The default proof verifier is not supported. Pass "
+                           "in --disable_certificate_verification.";
+      return nullptr;
+    }
   }
 
   // Build the client, and try to connect.

quiche/quic/masque/masque_connection_pool.cc

diff --git a/quiche/quic/masque/masque_connection_pool.cc b/quiche/quic/masque/masque_connection_pool.cc
index af5c7d4..afca6b9 100644
--- a/quiche/quic/masque/masque_connection_pool.cc
+++ b/quiche/quic/masque/masque_connection_pool.cc
@@ -257,6 +257,10 @@
     proof_verifier_ = std::make_unique<FakeProofVerifier>();
   } else {
     proof_verifier_ = CreateDefaultProofVerifier(host_);
+    if (!proof_verifier_) {
+      QUICHE_LOG(FATAL) << "The default proof verifier is not supported. Pass "
+                           "in --disable_certificate_verification.";
+    }
   }
   return true;
 }

quiche/quic/masque/masque_tcp_client_bin.cc

diff --git a/quiche/quic/masque/masque_tcp_client_bin.cc b/quiche/quic/masque/masque_tcp_client_bin.cc
index 5a0b4fd..5675dfe 100644
--- a/quiche/quic/masque/masque_tcp_client_bin.cc
+++ b/quiche/quic/masque/masque_tcp_client_bin.cc
@@ -128,6 +128,12 @@
       proof_verifier_ = std::make_unique<FakeProofVerifier>();
     } else {
       proof_verifier_ = CreateDefaultProofVerifier(url_.host());
+      if (!proof_verifier_) {
+        QUICHE_LOG(ERROR)
+            << "The default proof verifier is not supported. Pass "
+               "in --disable_certificate_verification.";
+        return false;
+      }
     }
     socket_address_ = tools::LookupAddress(
         address_family_for_lookup_, url_.host(), absl::StrCat(url_.port()));