Credentials: Use QsortCompare instead of strcmp for type comparison (g…

…rpc#28973) * Credentials: Use QsortCompare instead of strcmp for type comparison * Reviewer comments
zkkxu · Mar 3, 2022 · cc44f7c · cc44f7c
1 parent 55ba777
commit cc44f7c
Showing 1 changed file with 14 additions and 2 deletions.
diff --git a/src/core/lib/security/credentials/credentials.h b/src/core/lib/security/credentials/credentials.h
@@ -103,6 +103,10 @@ void grpc_override_well_known_credentials_path_getter(
 struct grpc_channel_credentials
     : grpc_core::RefCounted<grpc_channel_credentials> {
  public:
+  // The pointer value \a type is used to uniquely identify a creds
+  // implementation for down-casting purposes. Every creds implementation should
+  // use a unique string instance, which should be returned by all instances of
+  // that creds implementation.
   explicit grpc_channel_credentials(const char* type) : type_(type) {}
   ~grpc_channel_credentials() override = default;
 
@@ -143,7 +147,9 @@ struct grpc_channel_credentials
   // as equal (assuming other channel args match).
   int cmp(const grpc_channel_credentials* other) const {
     GPR_ASSERT(other != nullptr);
-    int r = strcmp(type(), other->type());
+    // Intentionally uses grpc_core::QsortCompare instead of strcmp as a safety
+    // against different grpc_channel_credentials types using the same name.
+    int r = grpc_core::QsortCompare(type(), other->type());
     if (r != 0) return r;
     return cmp_impl(other);
   }
@@ -198,6 +204,10 @@ struct grpc_call_credentials
     grpc_core::RefCountedPtr<grpc_auth_context> auth_context;
   };
 
+  // The pointer value \a type is used to uniquely identify a creds
+  // implementation for down-casting purposes. Every creds implementation should
+  // use a unique string instance, which should be returned by all instances of
+  // that creds implementation.
   explicit grpc_call_credentials(
       const char* type,
       grpc_security_level min_security_level = GRPC_PRIVACY_AND_INTEGRITY)
@@ -219,7 +229,9 @@ struct grpc_call_credentials
   // credentials as effectively the same..
   int cmp(const grpc_call_credentials* other) const {
     GPR_ASSERT(other != nullptr);
-    int r = strcmp(type(), other->type());
+    // Intentionally uses grpc_core::QsortCompare instead of strcmp as a safety
+    // against different grpc_call_credentials types using the same name.
+    int r = grpc_core::QsortCompare(type(), other->type());
     if (r != 0) return r;
     return cmp_impl(other);
   }