[refactor] More post-NSS WebCrypto cleanups (utility functions).

components/webcrypto/algorithms/secret_key_util.h

+// Copyright 2014 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.
+
+#ifndef COMPONENTS_WEBCRYPTO_ALGORITHMS_SECRET_KEY_UTIL_
+#define COMPONENTS_WEBCRYPTO_ALGORITHMS_SECRET_KEY_UTIL_
+
+#include <string>
+#include <vector>
+
+#include "third_party/WebKit/public/platform/WebCryptoAlgorithm.h"
+#include "third_party/WebKit/public/platform/WebCryptoKey.h"
+
+// This file contains functions shared by multiple symmetric key algorithms.
+
+namespace webcrypto {
+
+class CryptoData;
+class GenerateKeyResult;
+class JwkReader;
+class Status;
+
+// Generates a random secret key of the given bit length. If the bit length is
+// not a multiple of 8, then the resulting key will have ceil(keylen_bits / 8)
+// bytes, and the "unused" bits will be set to zero. This function does not do
+// any validation checks on the provided parameters.
+Status GenerateWebCryptoSecretKey(const blink::WebCryptoKeyAlgorithm& algorithm,
+                                  bool extractable,
+                                  blink::WebCryptoKeyUsageMask usages,
+                                  unsigned int keylen_bits,
+                                  GenerateKeyResult* result);
+
+// Creates a WebCrypto secret key given a the raw data. The provided |key_data|
+// will be copied into the new key. This function does not do any validation
+// checks for the provided parameters.
+Status CreateWebCryptoSecretKey(const CryptoData& key_data,
+                                const blink::WebCryptoKeyAlgorithm& algorithm,
+                                bool extractable,
+                                blink::WebCryptoKeyUsageMask usages,
+                                blink::WebCryptoKey* key);
+
+// Writes a JWK-formatted symmetric key to |jwk_key_data|.
+//  * raw_key_data: The actual key data
+//  * algorithm: The JWK algorithm name (i.e. "alg")
+//  * extractable: The JWK extractability (i.e. "ext")
+//  * usages: The JWK usages (i.e. "key_ops")
+void WriteSecretKeyJwk(const CryptoData& raw_key_data,
+                       const std::string& algorithm,
+                       bool extractable,
+                       blink::WebCryptoKeyUsageMask usages,
+                       std::vector<uint8_t>* jwk_key_data);
+
+// Parses a UTF-8 encoded JWK (key_data), and extracts the key material to
+// |*raw_key_data|. Returns Status::Success() on success, otherwise an error.
+// In order for this to succeed:
+//   * expected_extractable must be consistent with the JWK's "ext", if
+//     present.
+//   * expected_usages must be a subset of the JWK's "key_ops" if present.
+Status ReadSecretKeyNoExpectedAlgJwk(
+    const CryptoData& key_data,
+    bool expected_extractable,
+    blink::WebCryptoKeyUsageMask expected_usages,
+    std::vector<uint8_t>* raw_key_data,
+    JwkReader* jwk);
+
+}  // namespace webcrypto
+
+#endif  // COMPONENTS_WEBCRYPTO_ALGORITHMS_SECRET_KEY_UTIL_