Require extractable=false for KDF import

components/webcrypto/algorithms/hkdf.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <openssl/err.h>
 #include <openssl/hkdf.h>
 #include <stdint.h>
 
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
@@ skipping 34 matching lines @@
 
   Status ImportKeyRaw(const CryptoData& key_data,
                       const blink::WebCryptoAlgorithm& algorithm,
                       bool extractable,
                       blink::WebCryptoKeyUsageMask usages,
                       blink::WebCryptoKey* key) const {
     Status status = CheckKeyCreationUsages(kValidUsages, usages);
     if (status.IsError())
       return status;
 
+    if (extractable)
+      return Status::ErrorImportExtractableKdfKey();
+
     return CreateWebCryptoSecretKey(
         key_data, blink::WebCryptoKeyAlgorithm::createWithoutParams(
                       blink::WebCryptoAlgorithmIdHkdf),
         extractable, usages, key);
   }
 
   Status DeriveBits(const blink::WebCryptoAlgorithm& algorithm,
                     const blink::WebCryptoKey& base_key,
                     bool has_optional_length_bits,
                     unsigned int optional_length_bits,
@@ skipping 30 matching lines @@
     TruncateToBitLength(optional_length_bits, derived_bytes);
     return Status::Success();
   }
 
   Status DeserializeKeyForClone(const blink::WebCryptoKeyAlgorithm& algorithm,
                                 blink::WebCryptoKeyType type,
                                 bool extractable,
                                 blink::WebCryptoKeyUsageMask usages,
                                 const CryptoData& key_data,
                                 blink::WebCryptoKey* key) const override {
+    // NOTE: Unlike ImportKeyRaw(), this does not enforce extractable==false.
+    // This is intentional. Although keys cannot currently be created with
+    // extractable==true, earlier implementations permitted this, so
+    // de-serialization by structured clone should not reject them.
     return CreateWebCryptoSecretKey(key_data, algorithm, extractable, usages,
                                     key);
   }
 
   Status GetKeyLength(const blink::WebCryptoAlgorithm& key_length_algorithm,
                       bool* has_length_bits,
                       unsigned int* length_bits) const override {
     *has_length_bits = false;
     return Status::Success();
   }
 };
 
 }  // namespace
 
 std::unique_ptr<AlgorithmImplementation> CreateHkdfImplementation() {
   return base::WrapUnique(new HkdfImplementation);
 }
 
 }  // namespace webcrypto