Revert 284192 due to a failing test.

content/child/webcrypto/platform_crypto_nss.cc

Index: content/child/webcrypto/platform_crypto_nss.cc
diff --git a/content/child/webcrypto/platform_crypto_nss.cc b/content/child/webcrypto/platform_crypto_nss.cc
new file mode 100644
index 0000000000000000000000000000000000000000..c5c18afc3d47011e7106c085f9ca7eb2cfa4bc78
--- /dev/null
+++ b/content/child/webcrypto/platform_crypto_nss.cc
@@ -0,0 +1,1934 @@
+// 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.
+
+#include "content/child/webcrypto/platform_crypto.h"
+
+#include <cryptohi.h>
+#include <pk11pub.h>
+#include <secerr.h>
+#include <sechash.h>
+
+#include <vector>
+
+#include "base/lazy_instance.h"
+#include "base/logging.h"
+#include "base/memory/scoped_ptr.h"
+#include "content/child/webcrypto/crypto_data.h"
+#include "content/child/webcrypto/status.h"
+#include "content/child/webcrypto/webcrypto_util.h"
+#include "crypto/nss_util.h"
+#include "crypto/scoped_nss_types.h"
+#include "third_party/WebKit/public/platform/WebCryptoAlgorithm.h"
+#include "third_party/WebKit/public/platform/WebCryptoAlgorithmParams.h"
+#include "third_party/WebKit/public/platform/WebCryptoKeyAlgorithm.h"
+
+#if defined(USE_NSS)
+#include <dlfcn.h>
+#include <secoid.h>
+#endif
+
+// At the time of this writing:
+//   * Windows and Mac builds ship with their own copy of NSS (3.15+)
+//   * Linux builds use the system's libnss, which is 3.14 on Debian (but 3.15+
+//     on other distros).
+//
+// Since NSS provides AES-GCM support starting in version 3.15, it may be
+// unavailable for Linux Chrome users.
+//
+//  * !defined(CKM_AES_GCM)
+//
+//      This means that at build time, the NSS header pkcs11t.h is older than
+//      3.15. However at runtime support may be present.
+//
+//  * !defined(USE_NSS)
+//
+//      This means that Chrome is being built with an embedded copy of NSS,
+//      which can be assumed to be >= 3.15. On the other hand if USE_NSS is
+//      defined, it also implies running on Linux.
+//
+// TODO(eroman): Simplify this once 3.15+ is required by Linux builds.
+#if !defined(CKM_AES_GCM)
+#define CKM_AES_GCM 0x00001087
+
+struct CK_GCM_PARAMS {
+  CK_BYTE_PTR pIv;
+  CK_ULONG ulIvLen;
+  CK_BYTE_PTR pAAD;
+  CK_ULONG ulAADLen;
+  CK_ULONG ulTagBits;
+};
+#endif  // !defined(CKM_AES_GCM)
+
+namespace {
+
+// Signature for PK11_Encrypt and PK11_Decrypt.
+typedef SECStatus (*PK11_EncryptDecryptFunction)(PK11SymKey*,
+                                                 CK_MECHANISM_TYPE,
+                                                 SECItem*,
+                                                 unsigned char*,
+                                                 unsigned int*,
+                                                 unsigned int,
+                                                 const unsigned char*,
+                                                 unsigned int);
+
+// Signature for PK11_PubEncrypt
+typedef SECStatus (*PK11_PubEncryptFunction)(SECKEYPublicKey*,
+                                             CK_MECHANISM_TYPE,
+                                             SECItem*,
+                                             unsigned char*,
+                                             unsigned int*,
+                                             unsigned int,
+                                             const unsigned char*,
+                                             unsigned int,
+                                             void*);
+
+// Signature for PK11_PrivDecrypt
+typedef SECStatus (*PK11_PrivDecryptFunction)(SECKEYPrivateKey*,
+                                              CK_MECHANISM_TYPE,
+                                              SECItem*,
+                                              unsigned char*,
+                                              unsigned int*,
+                                              unsigned int,
+                                              const unsigned char*,
+                                              unsigned int);
+
+// Singleton to abstract away dynamically loading libnss3.so
+class NssRuntimeSupport {
+ public:
+  bool IsAesGcmSupported() const {
+    return pk11_encrypt_func_ && pk11_decrypt_func_;
+  }
+
+  bool IsRsaOaepSupported() const {
+    return pk11_pub_encrypt_func_ && pk11_priv_decrypt_func_ &&
+           internal_slot_does_oaep_;
+  }
+
+  // Returns NULL if unsupported.
+  PK11_EncryptDecryptFunction pk11_encrypt_func() const {
+    return pk11_encrypt_func_;
+  }
+
+  // Returns NULL if unsupported.
+  PK11_EncryptDecryptFunction pk11_decrypt_func() const {
+    return pk11_decrypt_func_;
+  }
+
+  // Returns NULL if unsupported.
+  PK11_PubEncryptFunction pk11_pub_encrypt_func() const {
+    return pk11_pub_encrypt_func_;
+  }
+
+  // Returns NULL if unsupported.
+  PK11_PrivDecryptFunction pk11_priv_decrypt_func() const {
+    return pk11_priv_decrypt_func_;
+  }
+
+ private:
+  friend struct base::DefaultLazyInstanceTraits<NssRuntimeSupport>;
+
+  NssRuntimeSupport() : internal_slot_does_oaep_(false) {
+#if !defined(USE_NSS)
+    // Using a bundled version of NSS that is guaranteed to have this symbol.
+    pk11_encrypt_func_ = PK11_Encrypt;
+    pk11_decrypt_func_ = PK11_Decrypt;
+    pk11_pub_encrypt_func_ = PK11_PubEncrypt;
+    pk11_priv_decrypt_func_ = PK11_PrivDecrypt;
+    internal_slot_does_oaep_ = true;
+#else
+    // Using system NSS libraries and PCKS #11 modules, which may not have the
+    // necessary function (PK11_Encrypt) or mechanism support (CKM_AES_GCM).
+
+    // If PK11_Encrypt() was successfully resolved, then NSS will support
+    // AES-GCM directly. This was introduced in NSS 3.15.
+    pk11_encrypt_func_ = reinterpret_cast<PK11_EncryptDecryptFunction>(
+        dlsym(RTLD_DEFAULT, "PK11_Encrypt"));
+    pk11_decrypt_func_ = reinterpret_cast<PK11_EncryptDecryptFunction>(
+        dlsym(RTLD_DEFAULT, "PK11_Decrypt"));
+
+    // Even though NSS's pk11wrap layer may support
+    // PK11_PubEncrypt/PK11_PubDecrypt (introduced in NSS 3.16.2), it may have
+    // loaded a softoken that does not include OAEP support.
+    pk11_pub_encrypt_func_ = reinterpret_cast<PK11_PubEncryptFunction>(
+        dlsym(RTLD_DEFAULT, "PK11_PubEncrypt"));
+    pk11_priv_decrypt_func_ = reinterpret_cast<PK11_PrivDecryptFunction>(
+        dlsym(RTLD_DEFAULT, "PK11_PrivDecrypt"));
+    if (pk11_priv_decrypt_func_ && pk11_pub_encrypt_func_) {
+      crypto::ScopedPK11Slot slot(PK11_GetInternalKeySlot());
+      internal_slot_does_oaep_ =
+          !!PK11_DoesMechanism(slot.get(), CKM_RSA_PKCS_OAEP);
+    }
+#endif
+  }
+
+  PK11_EncryptDecryptFunction pk11_encrypt_func_;
+  PK11_EncryptDecryptFunction pk11_decrypt_func_;
+  PK11_PubEncryptFunction pk11_pub_encrypt_func_;
+  PK11_PrivDecryptFunction pk11_priv_decrypt_func_;
+  bool internal_slot_does_oaep_;
+};
+
+base::LazyInstance<NssRuntimeSupport>::Leaky g_nss_runtime_support =
+    LAZY_INSTANCE_INITIALIZER;
+
+}  // namespace
+
+namespace content {
+
+namespace webcrypto {
+
+namespace platform {
+
+// Each key maintains a copy of its serialized form
+// in either 'raw', 'pkcs8', or 'spki' format. This is to allow
+// structured cloning of keys synchronously from the target Blink
+// thread without having to lock access to the key.
+//
+// TODO(eroman): Take advantage of this for implementing exportKey(): no need
+//               to call into NSS if the serialized form already exists.
+//               http://crubg.com/366836
+class SymKey : public Key {
+ public:
+  static Status Create(crypto::ScopedPK11SymKey key, scoped_ptr<SymKey>* out) {
+    out->reset(new SymKey(key.Pass()));
+    return ExportKeyRaw(out->get(), &(*out)->serialized_key_);
+  }
+
+  PK11SymKey* key() { return key_.get(); }
+
+  virtual SymKey* AsSymKey() OVERRIDE { return this; }
+  virtual PublicKey* AsPublicKey() OVERRIDE { return NULL; }
+  virtual PrivateKey* AsPrivateKey() OVERRIDE { return NULL; }
+
+  virtual bool ThreadSafeSerializeForClone(
+      blink::WebVector<uint8>* key_data) OVERRIDE {
+    key_data->assign(Uint8VectorStart(serialized_key_), serialized_key_.size());
+    return true;
+  }
+
+ private:
+  explicit SymKey(crypto::ScopedPK11SymKey key) : key_(key.Pass()) {}
+
+  crypto::ScopedPK11SymKey key_;
+  std::vector<uint8> serialized_key_;
+
+  DISALLOW_COPY_AND_ASSIGN(SymKey);
+};
+
+class PublicKey : public Key {
+ public:
+  static Status Create(crypto::ScopedSECKEYPublicKey key,
+                       scoped_ptr<PublicKey>* out) {
+    out->reset(new PublicKey(key.Pass()));
+    return ExportKeySpki(out->get(), &(*out)->serialized_key_);
+  }
+
+  SECKEYPublicKey* key() { return key_.get(); }
+
+  virtual SymKey* AsSymKey() OVERRIDE { return NULL; }
+  virtual PublicKey* AsPublicKey() OVERRIDE { return this; }
+  virtual PrivateKey* AsPrivateKey() OVERRIDE { return NULL; }
+
+  virtual bool ThreadSafeSerializeForClone(
+      blink::WebVector<uint8>* key_data) OVERRIDE {
+    key_data->assign(Uint8VectorStart(serialized_key_), serialized_key_.size());
+    return true;
+  }
+
+ private:
+  explicit PublicKey(crypto::ScopedSECKEYPublicKey key) : key_(key.Pass()) {}
+
+  crypto::ScopedSECKEYPublicKey key_;
+  std::vector<uint8> serialized_key_;
+
+  DISALLOW_COPY_AND_ASSIGN(PublicKey);
+};
+
+class PrivateKey : public Key {
+ public:
+  static Status Create(crypto::ScopedSECKEYPrivateKey key,
+                       const blink::WebCryptoKeyAlgorithm& algorithm,
+                       scoped_ptr<PrivateKey>* out) {
+    out->reset(new PrivateKey(key.Pass()));
+    return ExportKeyPkcs8(out->get(), algorithm, &(*out)->serialized_key_);
+  }
+
+  SECKEYPrivateKey* key() { return key_.get(); }
+
+  virtual SymKey* AsSymKey() OVERRIDE { return NULL; }
+  virtual PublicKey* AsPublicKey() OVERRIDE { return NULL; }
+  virtual PrivateKey* AsPrivateKey() OVERRIDE { return this; }
+
+  virtual bool ThreadSafeSerializeForClone(
+      blink::WebVector<uint8>* key_data) OVERRIDE {
+    key_data->assign(Uint8VectorStart(serialized_key_), serialized_key_.size());
+    return true;
+  }
+
+ private:
+  explicit PrivateKey(crypto::ScopedSECKEYPrivateKey key) : key_(key.Pass()) {}
+
+  crypto::ScopedSECKEYPrivateKey key_;
+  std::vector<uint8> serialized_key_;
+
+  DISALLOW_COPY_AND_ASSIGN(PrivateKey);
+};
+
+namespace {
+
+Status NssSupportsAesGcm() {
+  if (g_nss_runtime_support.Get().IsAesGcmSupported())
+    return Status::Success();
+  return Status::ErrorUnsupported(
+      "NSS version doesn't support AES-GCM. Try using version 3.15 or later");
+}
+
+Status NssSupportsRsaOaep() {
+  if (g_nss_runtime_support.Get().IsRsaOaepSupported())
+    return Status::Success();
+  return Status::ErrorUnsupported(
+      "NSS version doesn't support RSA-OAEP. Try using version 3.16.2 or "
+      "later");
+}
+
+#if defined(USE_NSS) && !defined(OS_CHROMEOS)
+Status ErrorRsaKeyImportNotSupported() {
+  return Status::ErrorUnsupported(
+      "NSS version must be at least 3.16.2 for RSA key import. See "
+      "http://crbug.com/380424");
+}
+
+Status NssSupportsKeyImport(blink::WebCryptoAlgorithmId algorithm) {
+  // Prior to NSS 3.16.2 RSA key parameters were not validated. This is
+  // a security problem for RSA private key import from JWK which uses a
+  // CKA_ID based on the public modulus to retrieve the private key.
+
+  if (!IsAlgorithmRsa(algorithm))
+    return Status::Success();
+
+  if (!NSS_VersionCheck("3.16.2"))
+    return ErrorRsaKeyImportNotSupported();
+
+  // Also ensure that the version of Softoken is 3.16.2 or later.
+  crypto::ScopedPK11Slot slot(PK11_GetInternalSlot());
+  CK_SLOT_INFO info = {};
+  if (PK11_GetSlotInfo(slot.get(), &info) != SECSuccess)
+    return ErrorRsaKeyImportNotSupported();
+
+  // CK_SLOT_INFO.hardwareVersion contains the major.minor
+  // version info for Softoken in the corresponding .major/.minor
+  // fields, and .firmwareVersion contains the patch.build
+  // version info (in the .major/.minor fields)
+  if ((info.hardwareVersion.major > 3) ||
+      (info.hardwareVersion.major == 3 &&
+       (info.hardwareVersion.minor > 16 ||
+        (info.hardwareVersion.minor == 16 &&
+         info.firmwareVersion.major >= 2)))) {
+    return Status::Success();
+  }
+
+  return ErrorRsaKeyImportNotSupported();
+}
+#else
+Status NssSupportsKeyImport(blink::WebCryptoAlgorithmId) {
+  return Status::Success();
+}
+#endif
+
+// Creates a SECItem for the data in |buffer|. This does NOT make a copy, so
+// |buffer| should outlive the SECItem.
+SECItem MakeSECItemForBuffer(const CryptoData& buffer) {
+  SECItem item = {
+      siBuffer,
+      // NSS requires non-const data even though it is just for input.
+      const_cast<unsigned char*>(buffer.bytes()), buffer.byte_length()};
+  return item;
+}
+
+HASH_HashType WebCryptoAlgorithmToNSSHashType(
+    blink::WebCryptoAlgorithmId algorithm) {
+  switch (algorithm) {
+    case blink::WebCryptoAlgorithmIdSha1:
+      return HASH_AlgSHA1;
+    case blink::WebCryptoAlgorithmIdSha256:
+      return HASH_AlgSHA256;
+    case blink::WebCryptoAlgorithmIdSha384:
+      return HASH_AlgSHA384;
+    case blink::WebCryptoAlgorithmIdSha512:
+      return HASH_AlgSHA512;
+    default:
+      // Not a digest algorithm.
+      return HASH_AlgNULL;
+  }
+}
+
+CK_MECHANISM_TYPE WebCryptoHashToHMACMechanism(
+    const blink::WebCryptoAlgorithm& algorithm) {
+  switch (algorithm.id()) {
+    case blink::WebCryptoAlgorithmIdSha1:
+      return CKM_SHA_1_HMAC;
+    case blink::WebCryptoAlgorithmIdSha256:
+      return CKM_SHA256_HMAC;
+    case blink::WebCryptoAlgorithmIdSha384:
+      return CKM_SHA384_HMAC;
+    case blink::WebCryptoAlgorithmIdSha512:
+      return CKM_SHA512_HMAC;
+    default:
+      // Not a supported algorithm.
+      return CKM_INVALID_MECHANISM;
+  }
+}
+
+CK_MECHANISM_TYPE WebCryptoHashToDigestMechanism(
+    const blink::WebCryptoAlgorithm& algorithm) {
+  switch (algorithm.id()) {
+    case blink::WebCryptoAlgorithmIdSha1:
+      return CKM_SHA_1;
+    case blink::WebCryptoAlgorithmIdSha256:
+      return CKM_SHA256;
+    case blink::WebCryptoAlgorithmIdSha384:
+      return CKM_SHA384;
+    case blink::WebCryptoAlgorithmIdSha512:
+      return CKM_SHA512;
+    default:
+      // Not a supported algorithm.
+      return CKM_INVALID_MECHANISM;
+  }
+}
+
+CK_MECHANISM_TYPE WebCryptoHashToMGFMechanism(
+    const blink::WebCryptoAlgorithm& algorithm) {
+  switch (algorithm.id()) {
+    case blink::WebCryptoAlgorithmIdSha1:
+      return CKG_MGF1_SHA1;
+    case blink::WebCryptoAlgorithmIdSha256:
+      return CKG_MGF1_SHA256;
+    case blink::WebCryptoAlgorithmIdSha384:
+      return CKG_MGF1_SHA384;
+    case blink::WebCryptoAlgorithmIdSha512:
+      return CKG_MGF1_SHA512;
+    default:
+      return CKM_INVALID_MECHANISM;
+  }
+}
+
+bool InitializeRsaOaepParams(const blink::WebCryptoAlgorithm& hash,
+                             const CryptoData& label,
+                             CK_RSA_PKCS_OAEP_PARAMS* oaep_params) {
+  oaep_params->source = CKZ_DATA_SPECIFIED;
+  oaep_params->pSourceData = const_cast<unsigned char*>(label.bytes());
+  oaep_params->ulSourceDataLen = label.byte_length();
+  oaep_params->mgf = WebCryptoHashToMGFMechanism(hash);
+  oaep_params->hashAlg = WebCryptoHashToDigestMechanism(hash);
+
+  if (oaep_params->mgf == CKM_INVALID_MECHANISM ||
+      oaep_params->hashAlg == CKM_INVALID_MECHANISM) {
+    return false;
+  }
+
+  return true;
+}
+
+Status AesCbcEncryptDecrypt(EncryptOrDecrypt mode,
+                            SymKey* key,
+                            const CryptoData& iv,
+                            const CryptoData& data,
+                            std::vector<uint8>* buffer) {
+  CK_ATTRIBUTE_TYPE operation = (mode == ENCRYPT) ? CKA_ENCRYPT : CKA_DECRYPT;
+
+  SECItem iv_item = MakeSECItemForBuffer(iv);
+
+  crypto::ScopedSECItem param(PK11_ParamFromIV(CKM_AES_CBC_PAD, &iv_item));
+  if (!param)
+    return Status::OperationError();
+
+  crypto::ScopedPK11Context context(PK11_CreateContextBySymKey(
+      CKM_AES_CBC_PAD, operation, key->key(), param.get()));
+
+  if (!context.get())
+    return Status::OperationError();
+
+  // Oddly PK11_CipherOp takes input and output lengths as "int" rather than
+  // "unsigned int". Do some checks now to avoid integer overflowing.
+  if (data.byte_length() >= INT_MAX - AES_BLOCK_SIZE) {
+    // TODO(eroman): Handle this by chunking the input fed into NSS. Right now
+    // it doesn't make much difference since the one-shot API would end up
+    // blowing out the memory and crashing anyway.
+    return Status::ErrorDataTooLarge();
+  }
+
+  // PK11_CipherOp does an invalid memory access when given empty decryption
+  // input, or input which is not a multiple of the block size. See also
+  // https://bugzilla.mozilla.com/show_bug.cgi?id=921687.
+  if (operation == CKA_DECRYPT &&
+      (data.byte_length() == 0 || (data.byte_length() % AES_BLOCK_SIZE != 0))) {
+    return Status::OperationError();
+  }
+
+  // TODO(eroman): Refine the output buffer size. It can be computed exactly for
+  //               encryption, and can be smaller for decryption.
+  unsigned int output_max_len = data.byte_length() + AES_BLOCK_SIZE;
+  CHECK_GT(output_max_len, data.byte_length());
+
+  buffer->resize(output_max_len);
+
+  unsigned char* buffer_data = Uint8VectorStart(buffer);
+
+  int output_len;
+  if (SECSuccess != PK11_CipherOp(context.get(),
+                                  buffer_data,
+                                  &output_len,
+                                  buffer->size(),
+                                  data.bytes(),
+                                  data.byte_length())) {
+    return Status::OperationError();
+  }
+
+  unsigned int final_output_chunk_len;
+  if (SECSuccess != PK11_DigestFinal(context.get(),
+                                     buffer_data + output_len,
+                                     &final_output_chunk_len,
+                                     output_max_len - output_len)) {
+    return Status::OperationError();
+  }
+
+  buffer->resize(final_output_chunk_len + output_len);
+  return Status::Success();
+}
+
+// Helper to either encrypt or decrypt for AES-GCM. The result of encryption is
+// the concatenation of the ciphertext and the authentication tag. Similarly,
+// this is the expectation for the input to decryption.
+Status AesGcmEncryptDecrypt(EncryptOrDecrypt mode,
+                            SymKey* key,
+                            const CryptoData& data,
+                            const CryptoData& iv,
+                            const CryptoData& additional_data,
+                            unsigned int tag_length_bits,
+                            std::vector<uint8>* buffer) {
+  Status status = NssSupportsAesGcm();
+  if (status.IsError())
+    return status;
+
+  unsigned int tag_length_bytes = tag_length_bits / 8;
+
+  CK_GCM_PARAMS gcm_params = {0};
+  gcm_params.pIv = const_cast<unsigned char*>(iv.bytes());
+  gcm_params.ulIvLen = iv.byte_length();
+
+  gcm_params.pAAD = const_cast<unsigned char*>(additional_data.bytes());
+  gcm_params.ulAADLen = additional_data.byte_length();
+
+  gcm_params.ulTagBits = tag_length_bits;
+
+  SECItem param;
+  param.type = siBuffer;
+  param.data = reinterpret_cast<unsigned char*>(&gcm_params);
+  param.len = sizeof(gcm_params);
+
+  unsigned int buffer_size = 0;
+
+  // Calculate the output buffer size.
+  if (mode == ENCRYPT) {
+    // TODO(eroman): This is ugly, abstract away the safe integer arithmetic.
+    if (data.byte_length() > (UINT_MAX - tag_length_bytes))
+      return Status::ErrorDataTooLarge();
+    buffer_size = data.byte_length() + tag_length_bytes;
+  } else {
+    // TODO(eroman): In theory the buffer allocated for the plain text should be
+    // sized as |data.byte_length() - tag_length_bytes|.
+    //
+    // However NSS has a bug whereby it will fail if the output buffer size is
+    // not at least as large as the ciphertext:
+    //
+    // https://bugzilla.mozilla.org/show_bug.cgi?id=%20853674
+    //
+    // From the analysis of that bug it looks like it might be safe to pass a
+    // correctly sized buffer but lie about its size. Since resizing the
+    // WebCryptoArrayBuffer is expensive that hack may be worth looking into.
+    buffer_size = data.byte_length();
+  }
+
+  buffer->resize(buffer_size);
+  unsigned char* buffer_data = Uint8VectorStart(buffer);
+
+  PK11_EncryptDecryptFunction func =
+      (mode == ENCRYPT) ? g_nss_runtime_support.Get().pk11_encrypt_func()
+                        : g_nss_runtime_support.Get().pk11_decrypt_func();
+
+  unsigned int output_len = 0;
+  SECStatus result = func(key->key(),
+                          CKM_AES_GCM,
+                          &param,
+                          buffer_data,
+                          &output_len,
+                          buffer->size(),
+                          data.bytes(),
+                          data.byte_length());
+
+  if (result != SECSuccess)
+    return Status::OperationError();
+
+  // Unfortunately the buffer needs to be shrunk for decryption (see the NSS bug
+  // above).
+  buffer->resize(output_len);
+
+  return Status::Success();
+}
+
+CK_MECHANISM_TYPE WebCryptoAlgorithmToGenMechanism(
+    const blink::WebCryptoAlgorithm& algorithm) {
+  switch (algorithm.id()) {
+    case blink::WebCryptoAlgorithmIdAesCbc:
+    case blink::WebCryptoAlgorithmIdAesGcm:
+    case blink::WebCryptoAlgorithmIdAesKw:
+      return CKM_AES_KEY_GEN;
+    case blink::WebCryptoAlgorithmIdHmac:
+      return WebCryptoHashToHMACMechanism(algorithm.hmacKeyGenParams()->hash());
+    default:
+      return CKM_INVALID_MECHANISM;
+  }
+}
+
+bool CreatePublicKeyAlgorithm(const blink::WebCryptoAlgorithm& algorithm,
+                              SECKEYPublicKey* key,
+                              blink::WebCryptoKeyAlgorithm* key_algorithm) {
+  // TODO(eroman): What about other key types rsaPss, rsaOaep.
+  if (!key || key->keyType != rsaKey)
+    return false;
+
+  unsigned int modulus_length_bits = SECKEY_PublicKeyStrength(key) * 8;
+  CryptoData public_exponent(key->u.rsa.publicExponent.data,
+                             key->u.rsa.publicExponent.len);
+
+  switch (algorithm.paramsType()) {
+    case blink::WebCryptoAlgorithmParamsTypeRsaHashedImportParams:
+    case blink::WebCryptoAlgorithmParamsTypeRsaHashedKeyGenParams:
+      *key_algorithm = blink::WebCryptoKeyAlgorithm::createRsaHashed(
+          algorithm.id(),
+          modulus_length_bits,
+          public_exponent.bytes(),
+          public_exponent.byte_length(),
+          GetInnerHashAlgorithm(algorithm).id());
+      return true;
+    default:
+      return false;
+  }
+}
+
+bool CreatePrivateKeyAlgorithm(const blink::WebCryptoAlgorithm& algorithm,
+                               SECKEYPrivateKey* key,
+                               blink::WebCryptoKeyAlgorithm* key_algorithm) {
+  crypto::ScopedSECKEYPublicKey public_key(SECKEY_ConvertToPublicKey(key));
+  return CreatePublicKeyAlgorithm(algorithm, public_key.get(), key_algorithm);
+}
+
+// The Default IV for AES-KW. See http://www.ietf.org/rfc/rfc3394.txt
+// Section 2.2.3.1.
+// TODO(padolph): Move to common place to be shared with OpenSSL implementation.
+const unsigned char kAesIv[] = {0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6};
+
+// Sets NSS CK_MECHANISM_TYPE and CK_FLAGS corresponding to the input Web Crypto
+// algorithm ID.
+Status WebCryptoAlgorithmToNssMechFlags(
+    const blink::WebCryptoAlgorithm& algorithm,
+    CK_MECHANISM_TYPE* mechanism,
+    CK_FLAGS* flags) {
+  // Flags are verified at the Blink layer; here the flags are set to all
+  // possible operations of a key for the input algorithm type.
+  switch (algorithm.id()) {
+    case blink::WebCryptoAlgorithmIdHmac: {
+      const blink::WebCryptoAlgorithm hash = GetInnerHashAlgorithm(algorithm);
+      *mechanism = WebCryptoHashToHMACMechanism(hash);
+      if (*mechanism == CKM_INVALID_MECHANISM)
+        return Status::ErrorUnsupported();
+      *flags = CKF_SIGN | CKF_VERIFY;
+      return Status::Success();
+    }
+    case blink::WebCryptoAlgorithmIdAesCbc: {
+      *mechanism = CKM_AES_CBC;
+      *flags = CKF_ENCRYPT | CKF_DECRYPT;
+      return Status::Success();
+    }
+    case blink::WebCryptoAlgorithmIdAesKw: {
+      *mechanism = CKM_NSS_AES_KEY_WRAP;
+      *flags = CKF_WRAP | CKF_WRAP;
+      return Status::Success();
+    }
+    case blink::WebCryptoAlgorithmIdAesGcm: {
+      Status status = NssSupportsAesGcm();
+      if (status.IsError())
+        return status;
+      *mechanism = CKM_AES_GCM;
+      *flags = CKF_ENCRYPT | CKF_DECRYPT;
+      return Status::Success();
+    }
+    default:
+      return Status::ErrorUnsupported();
+  }
+}
+
+Status DoUnwrapSymKeyAesKw(const CryptoData& wrapped_key_data,
+                           SymKey* wrapping_key,
+                           CK_MECHANISM_TYPE mechanism,
+                           CK_FLAGS flags,
+                           crypto::ScopedPK11SymKey* unwrapped_key) {
+  DCHECK_GE(wrapped_key_data.byte_length(), 24u);
+  DCHECK_EQ(wrapped_key_data.byte_length() % 8, 0u);
+
+  SECItem iv_item = MakeSECItemForBuffer(CryptoData(kAesIv, sizeof(kAesIv)));
+  crypto::ScopedSECItem param_item(
+      PK11_ParamFromIV(CKM_NSS_AES_KEY_WRAP, &iv_item));
+  if (!param_item)
+    return Status::ErrorUnexpected();
+
+  SECItem cipher_text = MakeSECItemForBuffer(wrapped_key_data);
+
+  // The plaintext length is always 64 bits less than the data size.
+  const unsigned int plaintext_length = wrapped_key_data.byte_length() - 8;
+
+#if defined(USE_NSS)
+  // Part of workaround for
+  // https://bugzilla.mozilla.org/show_bug.cgi?id=981170. See the explanation
+  // later in this function.
+  PORT_SetError(0);
+#endif
+
+  crypto::ScopedPK11SymKey new_key(
+      PK11_UnwrapSymKeyWithFlags(wrapping_key->key(),
+                                 CKM_NSS_AES_KEY_WRAP,
+                                 param_item.get(),
+                                 &cipher_text,
+                                 mechanism,
+                                 CKA_FLAGS_ONLY,
+                                 plaintext_length,
+                                 flags));
+
+  // TODO(padolph): Use NSS PORT_GetError() and friends to report a more
+  // accurate error, providing if doesn't leak any information to web pages
+  // about other web crypto users, key details, etc.
+  if (!new_key)
+    return Status::OperationError();
+
+#if defined(USE_NSS)
+  // Workaround for https://bugzilla.mozilla.org/show_bug.cgi?id=981170
+  // which was fixed in NSS 3.16.0.
+  // If unwrap fails, NSS nevertheless returns a valid-looking PK11SymKey,
+  // with a reasonable length but with key data pointing to uninitialized
+  // memory.
+  // To understand this workaround see the fix for 981170:
+  // https://hg.mozilla.org/projects/nss/rev/753bb69e543c
+  if (!NSS_VersionCheck("3.16") && PORT_GetError() == SEC_ERROR_BAD_DATA)
+    return Status::OperationError();
+#endif
+
+  *unwrapped_key = new_key.Pass();
+  return Status::Success();
+}
+
+void CopySECItemToVector(const SECItem& item, std::vector<uint8>* out) {
+  out->assign(item.data, item.data + item.len);
+}
+
+// From PKCS#1 [http://tools.ietf.org/html/rfc3447]:
+//
+//    RSAPrivateKey ::= SEQUENCE {
+//      version           Version,
+//      modulus           INTEGER,  -- n
+//      publicExponent    INTEGER,  -- e
+//      privateExponent   INTEGER,  -- d
+//      prime1            INTEGER,  -- p
+//      prime2            INTEGER,  -- q
+//      exponent1         INTEGER,  -- d mod (p-1)
+//      exponent2         INTEGER,  -- d mod (q-1)
+//      coefficient       INTEGER,  -- (inverse of q) mod p
+//      otherPrimeInfos   OtherPrimeInfos OPTIONAL
+//    }
+//
+// Note that otherPrimeInfos is only applicable for version=1. Since NSS
+// doesn't use multi-prime can safely use version=0.
+struct RSAPrivateKey {
+  SECItem version;
+  SECItem modulus;
+  SECItem public_exponent;
+  SECItem private_exponent;
+  SECItem prime1;
+  SECItem prime2;
+  SECItem exponent1;
+  SECItem exponent2;
+  SECItem coefficient;
+};
+
+// The system NSS library doesn't have the new PK11_ExportDERPrivateKeyInfo
+// function yet (https://bugzilla.mozilla.org/show_bug.cgi?id=519255). So we
+// provide a fallback implementation.
+#if defined(USE_NSS)
+const SEC_ASN1Template RSAPrivateKeyTemplate[] = {
+    {SEC_ASN1_SEQUENCE, 0, NULL, sizeof(RSAPrivateKey)},
+    {SEC_ASN1_INTEGER, offsetof(RSAPrivateKey, version)},
+    {SEC_ASN1_INTEGER, offsetof(RSAPrivateKey, modulus)},
+    {SEC_ASN1_INTEGER, offsetof(RSAPrivateKey, public_exponent)},
+    {SEC_ASN1_INTEGER, offsetof(RSAPrivateKey, private_exponent)},
+    {SEC_ASN1_INTEGER, offsetof(RSAPrivateKey, prime1)},
+    {SEC_ASN1_INTEGER, offsetof(RSAPrivateKey, prime2)},
+    {SEC_ASN1_INTEGER, offsetof(RSAPrivateKey, exponent1)},
+    {SEC_ASN1_INTEGER, offsetof(RSAPrivateKey, exponent2)},
+    {SEC_ASN1_INTEGER, offsetof(RSAPrivateKey, coefficient)},
+    {0}};
+#endif  // defined(USE_NSS)
+
+// On success |value| will be filled with data which must be freed by
+// SECITEM_FreeItem(value, PR_FALSE);
+bool ReadUint(SECKEYPrivateKey* key,
+              CK_ATTRIBUTE_TYPE attribute,
+              SECItem* value) {
+  SECStatus rv = PK11_ReadRawAttribute(PK11_TypePrivKey, key, attribute, value);
+
+  // PK11_ReadRawAttribute() returns items of type siBuffer. However in order
+  // for the ASN.1 encoding to be correct, the items must be of type
+  // siUnsignedInteger.
+  value->type = siUnsignedInteger;
+
+  return rv == SECSuccess;
+}
+
+// Fills |out| with the RSA private key properties. Returns true on success.
+// Regardless of the return value, the caller must invoke FreeRSAPrivateKey()
+// to free up any allocated memory.
+//
+// The passed in RSAPrivateKey must be zero-initialized.
+bool InitRSAPrivateKey(SECKEYPrivateKey* key, RSAPrivateKey* out) {
+  if (key->keyType != rsaKey)
+    return false;
+
+  // Everything should be zero-ed out. These are just some spot checks.
+  DCHECK(!out->version.data);
+  DCHECK(!out->version.len);
+  DCHECK(!out->modulus.data);
+  DCHECK(!out->modulus.len);
+
+  // Always use version=0 since not using multi-prime.
+  if (!SEC_ASN1EncodeInteger(NULL, &out->version, 0))
+    return false;
+
+  if (!ReadUint(key, CKA_MODULUS, &out->modulus))
+    return false;
+  if (!ReadUint(key, CKA_PUBLIC_EXPONENT, &out->public_exponent))
+    return false;
+  if (!ReadUint(key, CKA_PRIVATE_EXPONENT, &out->private_exponent))
+    return false;
+  if (!ReadUint(key, CKA_PRIME_1, &out->prime1))
+    return false;
+  if (!ReadUint(key, CKA_PRIME_2, &out->prime2))
+    return false;
+  if (!ReadUint(key, CKA_EXPONENT_1, &out->exponent1))
+    return false;
+  if (!ReadUint(key, CKA_EXPONENT_2, &out->exponent2))
+    return false;
+  if (!ReadUint(key, CKA_COEFFICIENT, &out->coefficient))
+    return false;
+
+  return true;
+}
+
+struct FreeRsaPrivateKey {
+  void operator()(RSAPrivateKey* out) {
+    SECITEM_FreeItem(&out->version, PR_FALSE);
+    SECITEM_FreeItem(&out->modulus, PR_FALSE);
+    SECITEM_FreeItem(&out->public_exponent, PR_FALSE);
+    SECITEM_FreeItem(&out->private_exponent, PR_FALSE);
+    SECITEM_FreeItem(&out->prime1, PR_FALSE);
+    SECITEM_FreeItem(&out->prime2, PR_FALSE);
+    SECITEM_FreeItem(&out->exponent1, PR_FALSE);
+    SECITEM_FreeItem(&out->exponent2, PR_FALSE);
+    SECITEM_FreeItem(&out->coefficient, PR_FALSE);
+  }
+};
+
+}  // namespace
+
+class DigestorNSS : public blink::WebCryptoDigestor {
+ public:
+  explicit DigestorNSS(blink::WebCryptoAlgorithmId algorithm_id)
+      : hash_context_(NULL), algorithm_id_(algorithm_id) {}
+
+  virtual ~DigestorNSS() {
+    if (!hash_context_)
+      return;
+
+    HASH_Destroy(hash_context_);
+    hash_context_ = NULL;
+  }
+
+  virtual bool consume(const unsigned char* data, unsigned int size) {
+    return ConsumeWithStatus(data, size).IsSuccess();
+  }
+
+  Status ConsumeWithStatus(const unsigned char* data, unsigned int size) {
+    // Initialize everything if the object hasn't been initialized yet.
+    if (!hash_context_) {
+      Status error = Init();
+      if (!error.IsSuccess())
+        return error;
+    }
+
+    HASH_Update(hash_context_, data, size);
+
+    return Status::Success();
+  }
+
+  virtual bool finish(unsigned char*& result_data,
+                      unsigned int& result_data_size) {
+    Status error = FinishInternal(result_, &result_data_size);
+    if (!error.IsSuccess())
+      return false;
+    result_data = result_;
+    return true;
+  }
+
+  Status FinishWithVectorAndStatus(std::vector<uint8>* result) {
+    if (!hash_context_)
+      return Status::ErrorUnexpected();
+
+    unsigned int result_length = HASH_ResultLenContext(hash_context_);
+    result->resize(result_length);
+    unsigned char* digest = Uint8VectorStart(result);
+    unsigned int digest_size;  // ignored
+    return FinishInternal(digest, &digest_size);
+  }
+
+ private:
+  Status Init() {
+    HASH_HashType hash_type = WebCryptoAlgorithmToNSSHashType(algorithm_id_);
+
+    if (hash_type == HASH_AlgNULL)
+      return Status::ErrorUnsupported();
+
+    hash_context_ = HASH_Create(hash_type);
+    if (!hash_context_)
+      return Status::OperationError();
+
+    HASH_Begin(hash_context_);
+
+    return Status::Success();
+  }
+
+  Status FinishInternal(unsigned char* result, unsigned int* result_size) {
+    if (!hash_context_) {
+      Status error = Init();
+      if (!error.IsSuccess())
+        return error;
+    }
+
+    unsigned int hash_result_length = HASH_ResultLenContext(hash_context_);
+    DCHECK_LE(hash_result_length, static_cast<size_t>(HASH_LENGTH_MAX));
+
+    HASH_End(hash_context_, result, result_size, hash_result_length);
+
+    if (*result_size != hash_result_length)
+      return Status::ErrorUnexpected();
+    return Status::Success();
+  }
+
+  HASHContext* hash_context_;
+  blink::WebCryptoAlgorithmId algorithm_id_;
+  unsigned char result_[HASH_LENGTH_MAX];
+};
+
+Status ImportKeyRaw(const blink::WebCryptoAlgorithm& algorithm,
+                    const CryptoData& key_data,
+                    bool extractable,
+                    blink::WebCryptoKeyUsageMask usage_mask,
+                    blink::WebCryptoKey* key) {
+  DCHECK(!algorithm.isNull());
+
+  CK_MECHANISM_TYPE mechanism = CKM_INVALID_MECHANISM;
+  CK_FLAGS flags = 0;
+  Status status =
+      WebCryptoAlgorithmToNssMechFlags(algorithm, &mechanism, &flags);
+  if (status.IsError())
+    return status;
+
+  SECItem key_item = MakeSECItemForBuffer(key_data);
+
+  crypto::ScopedPK11Slot slot(PK11_GetInternalSlot());
+  crypto::ScopedPK11SymKey pk11_sym_key(
+      PK11_ImportSymKeyWithFlags(slot.get(),
+                                 mechanism,
+                                 PK11_OriginUnwrap,
+                                 CKA_FLAGS_ONLY,
+                                 &key_item,
+                                 flags,
+                                 false,
+                                 NULL));
+  if (!pk11_sym_key.get())
+    return Status::OperationError();
+
+  blink::WebCryptoKeyAlgorithm key_algorithm;
+  if (!CreateSecretKeyAlgorithm(
+          algorithm, key_data.byte_length(), &key_algorithm))
+    return Status::ErrorUnexpected();
+
+  scoped_ptr<SymKey> key_handle;
+  status = SymKey::Create(pk11_sym_key.Pass(), &key_handle);
+  if (status.IsError())
+    return status;
+
+  *key = blink::WebCryptoKey::create(key_handle.release(),
+                                     blink::WebCryptoKeyTypeSecret,
+                                     extractable,
+                                     key_algorithm,
+                                     usage_mask);
+  return Status::Success();
+}
+
+Status ExportKeyRaw(SymKey* key, std::vector<uint8>* buffer) {
+  if (PK11_ExtractKeyValue(key->key()) != SECSuccess)
+    return Status::OperationError();
+
+  // http://crbug.com/366427: the spec does not define any other failures for
+  // exporting, so none of the subsequent errors are spec compliant.
+  const SECItem* key_data = PK11_GetKeyData(key->key());
+  if (!key_data)
+    return Status::OperationError();
+
+  buffer->assign(key_data->data, key_data->data + key_data->len);
+
+  return Status::Success();
+}
+
+namespace {
+
+typedef scoped_ptr<CERTSubjectPublicKeyInfo,
+                   crypto::NSSDestroyer<CERTSubjectPublicKeyInfo,
+                                        SECKEY_DestroySubjectPublicKeyInfo> >
+    ScopedCERTSubjectPublicKeyInfo;
+
+// Validates an NSS KeyType against a WebCrypto import algorithm.
+bool ValidateNssKeyTypeAgainstInputAlgorithm(
+    KeyType key_type,
+    const blink::WebCryptoAlgorithm& algorithm) {
+  switch (key_type) {
+    case rsaKey:
+      return IsAlgorithmRsa(algorithm.id());
+    case dsaKey:
+    case ecKey:
+    case rsaPssKey:
+    case rsaOaepKey:
+      // TODO(padolph): Handle other key types.
+      break;
+    default:
+      break;
+  }
+  return false;
+}
+
+}  // namespace
+
+Status ImportKeySpki(const blink::WebCryptoAlgorithm& algorithm,
+                     const CryptoData& key_data,
+                     bool extractable,
+                     blink::WebCryptoKeyUsageMask usage_mask,
+                     blink::WebCryptoKey* key) {
+  Status status = NssSupportsKeyImport(algorithm.id());
+  if (status.IsError())
+    return status;
+
+  DCHECK(key);
+
+  if (!key_data.byte_length())
+    return Status::ErrorImportEmptyKeyData();
+  DCHECK(key_data.bytes());
+
+  // The binary blob 'key_data' is expected to be a DER-encoded ASN.1 Subject
+  // Public Key Info. Decode this to a CERTSubjectPublicKeyInfo.
+  SECItem spki_item = MakeSECItemForBuffer(key_data);
+  const ScopedCERTSubjectPublicKeyInfo spki(
+      SECKEY_DecodeDERSubjectPublicKeyInfo(&spki_item));
+  if (!spki)
+    return Status::DataError();
+
+  crypto::ScopedSECKEYPublicKey sec_public_key(
+      SECKEY_ExtractPublicKey(spki.get()));
+  if (!sec_public_key)
+    return Status::DataError();
+
+  const KeyType sec_key_type = SECKEY_GetPublicKeyType(sec_public_key.get());
+  if (!ValidateNssKeyTypeAgainstInputAlgorithm(sec_key_type, algorithm))
+    return Status::DataError();
+
+  blink::WebCryptoKeyAlgorithm key_algorithm;
+  if (!CreatePublicKeyAlgorithm(
+          algorithm, sec_public_key.get(), &key_algorithm))
+    return Status::ErrorUnexpected();
+
+  scoped_ptr<PublicKey> key_handle;
+  status = PublicKey::Create(sec_public_key.Pass(), &key_handle);
+  if (status.IsError())
+    return status;
+
+  *key = blink::WebCryptoKey::create(key_handle.release(),
+                                     blink::WebCryptoKeyTypePublic,
+                                     extractable,
+                                     key_algorithm,
+                                     usage_mask);
+
+  return Status::Success();
+}
+
+Status ExportKeySpki(PublicKey* key, std::vector<uint8>* buffer) {
+  const crypto::ScopedSECItem spki_der(
+      SECKEY_EncodeDERSubjectPublicKeyInfo(key->key()));
+  // http://crbug.com/366427: the spec does not define any other failures for
+  // exporting, so none of the subsequent errors are spec compliant.
+  if (!spki_der)
+    return Status::OperationError();
+
+  DCHECK(spki_der->data);
+  DCHECK(spki_der->len);
+
+  buffer->assign(spki_der->data, spki_der->data + spki_der->len);
+
+  return Status::Success();
+}
+
+Status ExportRsaPublicKey(PublicKey* key,
+                          std::vector<uint8>* modulus,
+                          std::vector<uint8>* public_exponent) {
+  DCHECK(key);
+  DCHECK(key->key());
+  if (key->key()->keyType != rsaKey)
+    return Status::ErrorUnsupported();
+  CopySECItemToVector(key->key()->u.rsa.modulus, modulus);
+  CopySECItemToVector(key->key()->u.rsa.publicExponent, public_exponent);
+  if (modulus->empty() || public_exponent->empty())
+    return Status::ErrorUnexpected();
+  return Status::Success();
+}
+
+void AssignVectorFromSecItem(const SECItem& item, std::vector<uint8>* output) {
+  output->assign(item.data, item.data + item.len);
+}
+
+Status ExportRsaPrivateKey(PrivateKey* key,
+                           std::vector<uint8>* modulus,
+                           std::vector<uint8>* public_exponent,
+                           std::vector<uint8>* private_exponent,
+                           std::vector<uint8>* prime1,
+                           std::vector<uint8>* prime2,
+                           std::vector<uint8>* exponent1,
+                           std::vector<uint8>* exponent2,
+                           std::vector<uint8>* coefficient) {
+  RSAPrivateKey key_props = {};
+  scoped_ptr<RSAPrivateKey, FreeRsaPrivateKey> free_private_key(&key_props);
+
+  if (!InitRSAPrivateKey(key->key(), &key_props))
+    return Status::OperationError();
+
+  AssignVectorFromSecItem(key_props.modulus, modulus);
+  AssignVectorFromSecItem(key_props.public_exponent, public_exponent);
+  AssignVectorFromSecItem(key_props.private_exponent, private_exponent);
+  AssignVectorFromSecItem(key_props.prime1, prime1);
+  AssignVectorFromSecItem(key_props.prime2, prime2);
+  AssignVectorFromSecItem(key_props.exponent1, exponent1);
+  AssignVectorFromSecItem(key_props.exponent2, exponent2);
+  AssignVectorFromSecItem(key_props.coefficient, coefficient);
+
+  return Status::Success();
+}
+
+Status ExportKeyPkcs8(PrivateKey* key,
+                      const blink::WebCryptoKeyAlgorithm& key_algorithm,
+                      std::vector<uint8>* buffer) {
+  // TODO(eroman): Support other RSA key types as they are added to Blink.
+  if (key_algorithm.id() != blink::WebCryptoAlgorithmIdRsaSsaPkcs1v1_5 &&
+      key_algorithm.id() != blink::WebCryptoAlgorithmIdRsaOaep)
+    return Status::ErrorUnsupported();
+
+// TODO(rsleevi): Implement OAEP support according to the spec.
+
+#if defined(USE_NSS)
+  // PK11_ExportDERPrivateKeyInfo isn't available. Use our fallback code.
+  const SECOidTag algorithm = SEC_OID_PKCS1_RSA_ENCRYPTION;
+  const int kPrivateKeyInfoVersion = 0;
+
+  SECKEYPrivateKeyInfo private_key_info = {};
+  RSAPrivateKey rsa_private_key = {};
+  scoped_ptr<RSAPrivateKey, FreeRsaPrivateKey> free_private_key(
+      &rsa_private_key);
+
+  // http://crbug.com/366427: the spec does not define any other failures for
+  // exporting, so none of the subsequent errors are spec compliant.
+  if (!InitRSAPrivateKey(key->key(), &rsa_private_key))
+    return Status::OperationError();
+
+  crypto::ScopedPLArenaPool arena(PORT_NewArena(DER_DEFAULT_CHUNKSIZE));
+  if (!arena.get())
+    return Status::OperationError();
+
+  if (!SEC_ASN1EncodeItem(arena.get(),
+                          &private_key_info.privateKey,
+                          &rsa_private_key,
+                          RSAPrivateKeyTemplate))
+    return Status::OperationError();
+
+  if (SECSuccess !=
+      SECOID_SetAlgorithmID(
+          arena.get(), &private_key_info.algorithm, algorithm, NULL))
+    return Status::OperationError();
+
+  if (!SEC_ASN1EncodeInteger(
+          arena.get(), &private_key_info.version, kPrivateKeyInfoVersion))
+    return Status::OperationError();
+
+  crypto::ScopedSECItem encoded_key(
+      SEC_ASN1EncodeItem(NULL,
+                         NULL,
+                         &private_key_info,
+                         SEC_ASN1_GET(SECKEY_PrivateKeyInfoTemplate)));
+#else   // defined(USE_NSS)
+  crypto::ScopedSECItem encoded_key(
+      PK11_ExportDERPrivateKeyInfo(key->key(), NULL));
+#endif  // defined(USE_NSS)
+
+  if (!encoded_key.get())
+    return Status::OperationError();
+
+  buffer->assign(encoded_key->data, encoded_key->data + encoded_key->len);
+  return Status::Success();
+}
+
+Status ImportKeyPkcs8(const blink::WebCryptoAlgorithm& algorithm,
+                      const CryptoData& key_data,
+                      bool extractable,
+                      blink::WebCryptoKeyUsageMask usage_mask,
+                      blink::WebCryptoKey* key) {
+  Status status = NssSupportsKeyImport(algorithm.id());
+  if (status.IsError())
+    return status;
+
+  DCHECK(key);
+
+  if (!key_data.byte_length())
+    return Status::ErrorImportEmptyKeyData();
+  DCHECK(key_data.bytes());
+
+  // The binary blob 'key_data' is expected to be a DER-encoded ASN.1 PKCS#8
+  // private key info object.
+  SECItem pki_der = MakeSECItemForBuffer(key_data);
+
+  SECKEYPrivateKey* seckey_private_key = NULL;
+  crypto::ScopedPK11Slot slot(PK11_GetInternalSlot());
+  if (PK11_ImportDERPrivateKeyInfoAndReturnKey(slot.get(),
+                                               &pki_der,
+                                               NULL,    // nickname
+                                               NULL,    // publicValue
+                                               false,   // isPerm
+                                               false,   // isPrivate
+                                               KU_ALL,  // usage
+                                               &seckey_private_key,
+                                               NULL) != SECSuccess) {
+    return Status::DataError();
+  }
+  DCHECK(seckey_private_key);
+  crypto::ScopedSECKEYPrivateKey private_key(seckey_private_key);
+
+  const KeyType sec_key_type = SECKEY_GetPrivateKeyType(private_key.get());
+  if (!ValidateNssKeyTypeAgainstInputAlgorithm(sec_key_type, algorithm))
+    return Status::DataError();
+
+  blink::WebCryptoKeyAlgorithm key_algorithm;
+  if (!CreatePrivateKeyAlgorithm(algorithm, private_key.get(), &key_algorithm))
+    return Status::ErrorUnexpected();
+
+  scoped_ptr<PrivateKey> key_handle;
+  status = PrivateKey::Create(private_key.Pass(), key_algorithm, &key_handle);
+  if (status.IsError())
+    return status;
+
+  *key = blink::WebCryptoKey::create(key_handle.release(),
+                                     blink::WebCryptoKeyTypePrivate,
+                                     extractable,
+                                     key_algorithm,
+                                     usage_mask);
+
+  return Status::Success();
+}
+
+// -----------------------------------
+// Hmac
+// -----------------------------------
+
+Status SignHmac(SymKey* key,
+                const blink::WebCryptoAlgorithm& hash,
+                const CryptoData& data,
+                std::vector<uint8>* buffer) {
+  DCHECK_EQ(PK11_GetMechanism(key->key()), WebCryptoHashToHMACMechanism(hash));
+
+  SECItem param_item = {siBuffer, NULL, 0};
+  SECItem data_item = MakeSECItemForBuffer(data);
+  // First call is to figure out the length.
+  SECItem signature_item = {siBuffer, NULL, 0};
+
+  if (PK11_SignWithSymKey(key->key(),
+                          PK11_GetMechanism(key->key()),
+                          &param_item,
+                          &signature_item,
+                          &data_item) != SECSuccess) {
+    return Status::OperationError();
+  }
+
+  DCHECK_NE(0u, signature_item.len);
+
+  buffer->resize(signature_item.len);
+  signature_item.data = Uint8VectorStart(buffer);
+
+  if (PK11_SignWithSymKey(key->key(),
+                          PK11_GetMechanism(key->key()),
+                          &param_item,
+                          &signature_item,
+                          &data_item) != SECSuccess) {
+    return Status::OperationError();
+  }
+
+  DCHECK_EQ(buffer->size(), signature_item.len);
+  return Status::Success();
+}
+
+// -----------------------------------
+// RsaOaep
+// -----------------------------------
+
+Status EncryptRsaOaep(PublicKey* key,
+                      const blink::WebCryptoAlgorithm& hash,
+                      const CryptoData& label,
+                      const CryptoData& data,
+                      std::vector<uint8>* buffer) {
+  Status status = NssSupportsRsaOaep();
+  if (status.IsError())
+    return status;
+
+  CK_RSA_PKCS_OAEP_PARAMS oaep_params = {0};
+  if (!InitializeRsaOaepParams(hash, label, &oaep_params))
+    return Status::ErrorUnsupported();
+
+  SECItem param;
+  param.type = siBuffer;
+  param.data = reinterpret_cast<unsigned char*>(&oaep_params);
+  param.len = sizeof(oaep_params);
+
+  buffer->resize(SECKEY_PublicKeyStrength(key->key()));
+  unsigned char* buffer_data = Uint8VectorStart(buffer);
+  unsigned int output_len;
+  if (g_nss_runtime_support.Get().pk11_pub_encrypt_func()(key->key(),
+                                                          CKM_RSA_PKCS_OAEP,
+                                                          &param,
+                                                          buffer_data,
+                                                          &output_len,
+                                                          buffer->size(),
+                                                          data.bytes(),
+                                                          data.byte_length(),
+                                                          NULL) != SECSuccess) {
+    return Status::OperationError();
+  }
+
+  DCHECK_LE(output_len, buffer->size());
+  buffer->resize(output_len);
+  return Status::Success();
+}
+
+Status DecryptRsaOaep(PrivateKey* key,
+                      const blink::WebCryptoAlgorithm& hash,
+                      const CryptoData& label,
+                      const CryptoData& data,
+                      std::vector<uint8>* buffer) {
+  Status status = NssSupportsRsaOaep();
+  if (status.IsError())
+    return status;
+
+  CK_RSA_PKCS_OAEP_PARAMS oaep_params = {0};
+  if (!InitializeRsaOaepParams(hash, label, &oaep_params))
+    return Status::ErrorUnsupported();
+
+  SECItem param;
+  param.type = siBuffer;
+  param.data = reinterpret_cast<unsigned char*>(&oaep_params);
+  param.len = sizeof(oaep_params);
+
+  const int modulus_length_bytes = PK11_GetPrivateModulusLen(key->key());
+  if (modulus_length_bytes <= 0)
+    return Status::ErrorUnexpected();
+
+  buffer->resize(modulus_length_bytes);
+
+  unsigned char* buffer_data = Uint8VectorStart(buffer);
+  unsigned int output_len;
+  if (g_nss_runtime_support.Get().pk11_priv_decrypt_func()(
+          key->key(),
+          CKM_RSA_PKCS_OAEP,
+          &param,
+          buffer_data,
+          &output_len,
+          buffer->size(),
+          data.bytes(),
+          data.byte_length()) != SECSuccess) {
+    return Status::OperationError();
+  }
+
+  DCHECK_LE(output_len, buffer->size());
+  buffer->resize(output_len);
+  return Status::Success();
+}
+
+// -----------------------------------
+// RsaSsaPkcs1v1_5
+// -----------------------------------
+
+Status SignRsaSsaPkcs1v1_5(PrivateKey* key,
+                           const blink::WebCryptoAlgorithm& hash,
+                           const CryptoData& data,
+                           std::vector<uint8>* buffer) {
+  // Pick the NSS signing algorithm by combining RSA-SSA (RSA PKCS1) and the
+  // inner hash of the input Web Crypto algorithm.
+  SECOidTag sign_alg_tag;
+  switch (hash.id()) {
+    case blink::WebCryptoAlgorithmIdSha1:
+      sign_alg_tag = SEC_OID_PKCS1_SHA1_WITH_RSA_ENCRYPTION;
+      break;
+    case blink::WebCryptoAlgorithmIdSha256:
+      sign_alg_tag = SEC_OID_PKCS1_SHA256_WITH_RSA_ENCRYPTION;
+      break;
+    case blink::WebCryptoAlgorithmIdSha384:
+      sign_alg_tag = SEC_OID_PKCS1_SHA384_WITH_RSA_ENCRYPTION;
+      break;
+    case blink::WebCryptoAlgorithmIdSha512:
+      sign_alg_tag = SEC_OID_PKCS1_SHA512_WITH_RSA_ENCRYPTION;
+      break;
+    default:
+      return Status::ErrorUnsupported();
+  }
+
+  crypto::ScopedSECItem signature_item(SECITEM_AllocItem(NULL, NULL, 0));
+  if (SEC_SignData(signature_item.get(),
+                   data.bytes(),
+                   data.byte_length(),
+                   key->key(),
+                   sign_alg_tag) != SECSuccess) {
+    return Status::OperationError();
+  }
+
+  buffer->assign(signature_item->data,
+                 signature_item->data + signature_item->len);
+  return Status::Success();
+}
+
+Status VerifyRsaSsaPkcs1v1_5(PublicKey* key,
+                             const blink::WebCryptoAlgorithm& hash,
+                             const CryptoData& signature,
+                             const CryptoData& data,
+                             bool* signature_match) {
+  const SECItem signature_item = MakeSECItemForBuffer(signature);
+
+  SECOidTag hash_alg_tag;
+  switch (hash.id()) {
+    case blink::WebCryptoAlgorithmIdSha1:
+      hash_alg_tag = SEC_OID_SHA1;
+      break;
+    case blink::WebCryptoAlgorithmIdSha256:
+      hash_alg_tag = SEC_OID_SHA256;
+      break;
+    case blink::WebCryptoAlgorithmIdSha384:
+      hash_alg_tag = SEC_OID_SHA384;
+      break;
+    case blink::WebCryptoAlgorithmIdSha512:
+      hash_alg_tag = SEC_OID_SHA512;
+      break;
+    default:
+      return Status::ErrorUnsupported();
+  }
+
+  *signature_match =
+      SECSuccess == VFY_VerifyDataDirect(data.bytes(),
+                                         data.byte_length(),
+                                         key->key(),
+                                         &signature_item,
+                                         SEC_OID_PKCS1_RSA_ENCRYPTION,
+                                         hash_alg_tag,
+                                         NULL,
+                                         NULL);
+  return Status::Success();
+}
+
+Status EncryptDecryptAesCbc(EncryptOrDecrypt mode,
+                            SymKey* key,
+                            const CryptoData& data,
+                            const CryptoData& iv,
+                            std::vector<uint8>* buffer) {
+  // TODO(eroman): Inline.
+  return AesCbcEncryptDecrypt(mode, key, iv, data, buffer);
+}
+
+Status EncryptDecryptAesGcm(EncryptOrDecrypt mode,
+                            SymKey* key,
+                            const CryptoData& data,
+                            const CryptoData& iv,
+                            const CryptoData& additional_data,
+                            unsigned int tag_length_bits,
+                            std::vector<uint8>* buffer) {
+  // TODO(eroman): Inline.
+  return AesGcmEncryptDecrypt(
+      mode, key, data, iv, additional_data, tag_length_bits, buffer);
+}
+
+// -----------------------------------
+// Key generation
+// -----------------------------------
+
+Status GenerateRsaKeyPair(const blink::WebCryptoAlgorithm& algorithm,
+                          bool extractable,
+                          blink::WebCryptoKeyUsageMask public_key_usage_mask,
+                          blink::WebCryptoKeyUsageMask private_key_usage_mask,
+                          unsigned int modulus_length_bits,
+                          unsigned long public_exponent,
+                          blink::WebCryptoKey* public_key,
+                          blink::WebCryptoKey* private_key) {
+  if (algorithm.id() == blink::WebCryptoAlgorithmIdRsaOaep) {
+    Status status = NssSupportsRsaOaep();
+    if (status.IsError())
+      return status;
+  }
+
+  crypto::ScopedPK11Slot slot(PK11_GetInternalKeySlot());
+  if (!slot)
+    return Status::OperationError();
+
+  PK11RSAGenParams rsa_gen_params;
+  // keySizeInBits is a signed type, don't pass in a negative value.
+  if (modulus_length_bits > INT_MAX)
+    return Status::OperationError();
+  rsa_gen_params.keySizeInBits = modulus_length_bits;
+  rsa_gen_params.pe = public_exponent;
+
+  // Flags are verified at the Blink layer; here the flags are set to all
+  // possible operations for the given key type.
+  CK_FLAGS operation_flags;
+  switch (algorithm.id()) {
+    case blink::WebCryptoAlgorithmIdRsaOaep:
+      operation_flags = CKF_ENCRYPT | CKF_DECRYPT | CKF_WRAP | CKF_UNWRAP;
+      break;
+    case blink::WebCryptoAlgorithmIdRsaSsaPkcs1v1_5:
+      operation_flags = CKF_SIGN | CKF_VERIFY;
+      break;
+    default:
+      NOTREACHED();
+      return Status::ErrorUnexpected();
+  }
+  const CK_FLAGS operation_flags_mask =
+      CKF_ENCRYPT | CKF_DECRYPT | CKF_SIGN | CKF_VERIFY | CKF_WRAP | CKF_UNWRAP;
+
+  // The private key must be marked as insensitive and extractable, otherwise it
+  // cannot later be exported in unencrypted form or structured-cloned.
+  const PK11AttrFlags attribute_flags =
+      PK11_ATTR_INSENSITIVE | PK11_ATTR_EXTRACTABLE;
+
+  // Note: NSS does not generate an sec_public_key if the call below fails,
+  // so there is no danger of a leaked sec_public_key.
+  SECKEYPublicKey* sec_public_key = NULL;
+  crypto::ScopedSECKEYPrivateKey scoped_sec_private_key(
+      PK11_GenerateKeyPairWithOpFlags(slot.get(),
+                                      CKM_RSA_PKCS_KEY_PAIR_GEN,
+                                      &rsa_gen_params,
+                                      &sec_public_key,
+                                      attribute_flags,
+                                      operation_flags,
+                                      operation_flags_mask,
+                                      NULL));
+  if (!scoped_sec_private_key)
+    return Status::OperationError();
+
+  blink::WebCryptoKeyAlgorithm key_algorithm;
+  if (!CreatePublicKeyAlgorithm(algorithm, sec_public_key, &key_algorithm))
+    return Status::ErrorUnexpected();
+
+  scoped_ptr<PublicKey> public_key_handle;
+  Status status = PublicKey::Create(
+      crypto::ScopedSECKEYPublicKey(sec_public_key), &public_key_handle);
+  if (status.IsError())
+    return status;
+
+  scoped_ptr<PrivateKey> private_key_handle;
+  status = PrivateKey::Create(
+      scoped_sec_private_key.Pass(), key_algorithm, &private_key_handle);
+  if (status.IsError())
+    return status;
+
+  *public_key = blink::WebCryptoKey::create(public_key_handle.release(),
+                                            blink::WebCryptoKeyTypePublic,
+                                            true,
+                                            key_algorithm,
+                                            public_key_usage_mask);
+  *private_key = blink::WebCryptoKey::create(private_key_handle.release(),
+                                             blink::WebCryptoKeyTypePrivate,
+                                             extractable,
+                                             key_algorithm,
+                                             private_key_usage_mask);
+
+  return Status::Success();
+}
+
+void Init() {
+  crypto::EnsureNSSInit();
+}
+
+Status DigestSha(blink::WebCryptoAlgorithmId algorithm,
+                 const CryptoData& data,
+                 std::vector<uint8>* buffer) {
+  DigestorNSS digestor(algorithm);
+  Status error = digestor.ConsumeWithStatus(data.bytes(), data.byte_length());
+  // http://crbug.com/366427: the spec does not define any other failures for
+  // digest, so none of the subsequent errors are spec compliant.
+  if (!error.IsSuccess())
+    return error;
+  return digestor.FinishWithVectorAndStatus(buffer);
+}
+
+scoped_ptr<blink::WebCryptoDigestor> CreateDigestor(
+    blink::WebCryptoAlgorithmId algorithm_id) {
+  return scoped_ptr<blink::WebCryptoDigestor>(new DigestorNSS(algorithm_id));
+}
+
+Status GenerateSecretKey(const blink::WebCryptoAlgorithm& algorithm,
+                         bool extractable,
+                         blink::WebCryptoKeyUsageMask usage_mask,
+                         unsigned keylen_bytes,
+                         blink::WebCryptoKey* key) {
+  CK_MECHANISM_TYPE mech = WebCryptoAlgorithmToGenMechanism(algorithm);
+  blink::WebCryptoKeyType key_type = blink::WebCryptoKeyTypeSecret;
+
+  if (mech == CKM_INVALID_MECHANISM)
+    return Status::ErrorUnsupported();
+
+  crypto::ScopedPK11Slot slot(PK11_GetInternalKeySlot());
+  if (!slot)
+    return Status::OperationError();
+
+  crypto::ScopedPK11SymKey pk11_key(
+      PK11_KeyGen(slot.get(), mech, NULL, keylen_bytes, NULL));
+
+  if (!pk11_key)
+    return Status::OperationError();
+
+  blink::WebCryptoKeyAlgorithm key_algorithm;
+  if (!CreateSecretKeyAlgorithm(algorithm, keylen_bytes, &key_algorithm))
+    return Status::ErrorUnexpected();
+
+  scoped_ptr<SymKey> key_handle;
+  Status status = SymKey::Create(pk11_key.Pass(), &key_handle);
+  if (status.IsError())
+    return status;
+
+  *key = blink::WebCryptoKey::create(
+      key_handle.release(), key_type, extractable, key_algorithm, usage_mask);
+  return Status::Success();
+}
+
+Status ImportRsaPublicKey(const blink::WebCryptoAlgorithm& algorithm,
+                          bool extractable,
+                          blink::WebCryptoKeyUsageMask usage_mask,
+                          const CryptoData& modulus_data,
+                          const CryptoData& exponent_data,
+                          blink::WebCryptoKey* key) {
+  if (!modulus_data.byte_length())
+    return Status::ErrorImportRsaEmptyModulus();
+
+  if (!exponent_data.byte_length())
+    return Status::ErrorImportRsaEmptyExponent();
+
+  DCHECK(modulus_data.bytes());
+  DCHECK(exponent_data.bytes());
+
+  // NSS does not provide a way to create an RSA public key directly from the
+  // modulus and exponent values, but it can import an DER-encoded ASN.1 blob
+  // with these values and create the public key from that. The code below
+  // follows the recommendation described in
+  // https://developer.mozilla.org/en-US/docs/NSS/NSS_Tech_Notes/nss_tech_note7
+
+  // Pack the input values into a struct compatible with NSS ASN.1 encoding, and
+  // set up an ASN.1 encoder template for it.
+  struct RsaPublicKeyData {
+    SECItem modulus;
+    SECItem exponent;
+  };
+  const RsaPublicKeyData pubkey_in = {
+      {siUnsignedInteger, const_cast<unsigned char*>(modulus_data.bytes()),
+       modulus_data.byte_length()},
+      {siUnsignedInteger, const_cast<unsigned char*>(exponent_data.bytes()),
+       exponent_data.byte_length()}};
+  const SEC_ASN1Template rsa_public_key_template[] = {
+      {SEC_ASN1_SEQUENCE, 0, NULL, sizeof(RsaPublicKeyData)},
+      {SEC_ASN1_INTEGER, offsetof(RsaPublicKeyData, modulus), },
+      {SEC_ASN1_INTEGER, offsetof(RsaPublicKeyData, exponent), },
+      {0, }};
+
+  // DER-encode the public key.
+  crypto::ScopedSECItem pubkey_der(
+      SEC_ASN1EncodeItem(NULL, NULL, &pubkey_in, rsa_public_key_template));
+  if (!pubkey_der)
+    return Status::OperationError();
+
+  // Import the DER-encoded public key to create an RSA SECKEYPublicKey.
+  crypto::ScopedSECKEYPublicKey pubkey(
+      SECKEY_ImportDERPublicKey(pubkey_der.get(), CKK_RSA));
+  if (!pubkey)
+    return Status::OperationError();
+
+  blink::WebCryptoKeyAlgorithm key_algorithm;
+  if (!CreatePublicKeyAlgorithm(algorithm, pubkey.get(), &key_algorithm))
+    return Status::ErrorUnexpected();
+
+  scoped_ptr<PublicKey> key_handle;
+  Status status = PublicKey::Create(pubkey.Pass(), &key_handle);
+  if (status.IsError())
+    return status;
+
+  *key = blink::WebCryptoKey::create(key_handle.release(),
+                                     blink::WebCryptoKeyTypePublic,
+                                     extractable,
+                                     key_algorithm,
+                                     usage_mask);
+  return Status::Success();
+}
+
+struct DestroyGenericObject {
+  void operator()(PK11GenericObject* o) const {
+    if (o)
+      PK11_DestroyGenericObject(o);
+  }
+};
+
+typedef scoped_ptr<PK11GenericObject, DestroyGenericObject>
+    ScopedPK11GenericObject;
+
+// Helper to add an attribute to a template.
+void AddAttribute(CK_ATTRIBUTE_TYPE type,
+                  void* value,
+                  unsigned long length,
+                  std::vector<CK_ATTRIBUTE>* templ) {
+  CK_ATTRIBUTE attribute = {type, value, length};
+  templ->push_back(attribute);
+}
+
+// Helper to optionally add an attribute to a template, if the provided data is
+// non-empty.
+void AddOptionalAttribute(CK_ATTRIBUTE_TYPE type,
+                          const CryptoData& data,
+                          std::vector<CK_ATTRIBUTE>* templ) {
+  if (!data.byte_length())
+    return;
+  CK_ATTRIBUTE attribute = {type, const_cast<unsigned char*>(data.bytes()),
+                            data.byte_length()};
+  templ->push_back(attribute);
+}
+
+Status ImportRsaPrivateKey(const blink::WebCryptoAlgorithm& algorithm,
+                           bool extractable,
+                           blink::WebCryptoKeyUsageMask usage_mask,
+                           const CryptoData& modulus,
+                           const CryptoData& public_exponent,
+                           const CryptoData& private_exponent,
+                           const CryptoData& prime1,
+                           const CryptoData& prime2,
+                           const CryptoData& exponent1,
+                           const CryptoData& exponent2,
+                           const CryptoData& coefficient,
+                           blink::WebCryptoKey* key) {
+  Status status = NssSupportsKeyImport(algorithm.id());
+  if (status.IsError())
+    return status;
+
+  CK_OBJECT_CLASS obj_class = CKO_PRIVATE_KEY;
+  CK_KEY_TYPE key_type = CKK_RSA;
+  CK_BBOOL ck_false = CK_FALSE;
+
+  std::vector<CK_ATTRIBUTE> key_template;
+
+  AddAttribute(CKA_CLASS, &obj_class, sizeof(obj_class), &key_template);
+  AddAttribute(CKA_KEY_TYPE, &key_type, sizeof(key_type), &key_template);
+  AddAttribute(CKA_TOKEN, &ck_false, sizeof(ck_false), &key_template);
+  AddAttribute(CKA_SENSITIVE, &ck_false, sizeof(ck_false), &key_template);
+  AddAttribute(CKA_PRIVATE, &ck_false, sizeof(ck_false), &key_template);
+
+  // Required properties.
+  AddOptionalAttribute(CKA_MODULUS, modulus, &key_template);
+  AddOptionalAttribute(CKA_PUBLIC_EXPONENT, public_exponent, &key_template);
+  AddOptionalAttribute(CKA_PRIVATE_EXPONENT, private_exponent, &key_template);
+
+  // Manufacture a CKA_ID so the created key can be retrieved later as a
+  // SECKEYPrivateKey using FindKeyByKeyID(). Unfortunately there isn't a more
+  // direct way to do this in NSS.
+  //
+  // For consistency with other NSS key creation methods, set the CKA_ID to
+  // PK11_MakeIDFromPubKey(). There are some problems with
+  // this approach:
+  //
+  //  (1) Prior to NSS 3.16.2, there is no parameter validation when creating
+  //      private keys. It is therefore possible to construct a key using the
+  //      known public modulus, and where all the other parameters are bogus.
+  //      FindKeyByKeyID() returns the first key matching the ID. So this would
+  //      effectively allow an attacker to retrieve a private key of their
+  //      choice.
+  //      TODO(eroman): Once NSS rolls and this is fixed, disallow RSA key
+  //                    import on older versions of NSS.
+  //                    http://crbug.com/378315
+  //
+  //  (2) The ID space is shared by different key types. So theoretically
+  //      possible to retrieve a key of the wrong type which has a matching
+  //      CKA_ID. In practice I am told this is not likely except for small key
+  //      sizes, since would require constructing keys with the same public
+  //      data.
+  //
+  //  (3) FindKeyByKeyID() doesn't necessarily return the object that was just
+  //      created by CreateGenericObject. If the pre-existing key was
+  //      provisioned with flags incompatible with WebCrypto (for instance
+  //      marked sensitive) then this will break things.
+  SECItem modulus_item = MakeSECItemForBuffer(CryptoData(modulus));
+  crypto::ScopedSECItem object_id(PK11_MakeIDFromPubKey(&modulus_item));
+  AddOptionalAttribute(
+      CKA_ID, CryptoData(object_id->data, object_id->len), &key_template);
+
+  // Optional properties (all of these will have been specified or none).
+  AddOptionalAttribute(CKA_PRIME_1, prime1, &key_template);
+  AddOptionalAttribute(CKA_PRIME_2, prime2, &key_template);
+  AddOptionalAttribute(CKA_EXPONENT_1, exponent1, &key_template);
+  AddOptionalAttribute(CKA_EXPONENT_2, exponent2, &key_template);
+  AddOptionalAttribute(CKA_COEFFICIENT, coefficient, &key_template);
+
+  crypto::ScopedPK11Slot slot(PK11_GetInternalSlot());
+
+  ScopedPK11GenericObject key_object(PK11_CreateGenericObject(
+      slot.get(), &key_template[0], key_template.size(), PR_FALSE));
+
+  if (!key_object)
+    return Status::OperationError();
+
+  crypto::ScopedSECKEYPrivateKey private_key_tmp(
+      PK11_FindKeyByKeyID(slot.get(), object_id.get(), NULL));
+
+  // PK11_FindKeyByKeyID() may return a handle to an existing key, rather than
+  // the object created by PK11_CreateGenericObject().
+  crypto::ScopedSECKEYPrivateKey private_key(
+      SECKEY_CopyPrivateKey(private_key_tmp.get()));
+
+  if (!private_key)
+    return Status::OperationError();
+
+  blink::WebCryptoKeyAlgorithm key_algorithm;
+  if (!CreatePrivateKeyAlgorithm(algorithm, private_key.get(), &key_algorithm))
+    return Status::ErrorUnexpected();
+
+  scoped_ptr<PrivateKey> key_handle;
+  status = PrivateKey::Create(private_key.Pass(), key_algorithm, &key_handle);
+  if (status.IsError())
+    return status;
+
+  *key = blink::WebCryptoKey::create(key_handle.release(),
+                                     blink::WebCryptoKeyTypePrivate,
+                                     extractable,
+                                     key_algorithm,
+                                     usage_mask);
+  return Status::Success();
+}
+
+Status WrapSymKeyAesKw(PK11SymKey* key,
+                       SymKey* wrapping_key,
+                       std::vector<uint8>* buffer) {
+  // The data size must be at least 16 bytes and a multiple of 8 bytes.
+  // RFC 3394 does not specify a maximum allowed data length, but since only
+  // keys are being wrapped in this application (which are small), a reasonable
+  // max limit is whatever will fit into an unsigned. For the max size test,
+  // note that AES Key Wrap always adds 8 bytes to the input data size.
+  const unsigned int input_length = PK11_GetKeyLength(key);
+  DCHECK_GE(input_length, 16u);
+  DCHECK((input_length % 8) == 0);
+  if (input_length > UINT_MAX - 8)
+    return Status::ErrorDataTooLarge();
+
+  SECItem iv_item = MakeSECItemForBuffer(CryptoData(kAesIv, sizeof(kAesIv)));
+  crypto::ScopedSECItem param_item(
+      PK11_ParamFromIV(CKM_NSS_AES_KEY_WRAP, &iv_item));
+  if (!param_item)
+    return Status::ErrorUnexpected();
+
+  const unsigned int output_length = input_length + 8;
+  buffer->resize(output_length);
+  SECItem wrapped_key_item = MakeSECItemForBuffer(CryptoData(*buffer));
+
+  if (SECSuccess != PK11_WrapSymKey(CKM_NSS_AES_KEY_WRAP,
+                                    param_item.get(),
+                                    wrapping_key->key(),
+                                    key,
+                                    &wrapped_key_item)) {
+    return Status::OperationError();
+  }
+  if (output_length != wrapped_key_item.len)
+    return Status::ErrorUnexpected();
+
+  return Status::Success();
+}
+
+Status DecryptAesKw(SymKey* wrapping_key,
+                    const CryptoData& data,
+                    std::vector<uint8>* buffer) {
+  // Due to limitations in the NSS API for the AES-KW algorithm, |data| must be
+  // temporarily viewed as a symmetric key to be unwrapped (decrypted).
+  crypto::ScopedPK11SymKey decrypted;
+  Status status = DoUnwrapSymKeyAesKw(
+      data, wrapping_key, CKK_GENERIC_SECRET, 0, &decrypted);
+  if (status.IsError())
+    return status;
+
+  // Once the decrypt is complete, extract the resultant raw bytes from NSS and
+  // return them to the caller.
+  if (PK11_ExtractKeyValue(decrypted.get()) != SECSuccess)
+    return Status::OperationError();
+  const SECItem* const key_data = PK11_GetKeyData(decrypted.get());
+  if (!key_data)
+    return Status::OperationError();
+  buffer->assign(key_data->data, key_data->data + key_data->len);
+
+  return Status::Success();
+}
+
+Status EncryptAesKw(SymKey* wrapping_key,
+                    const CryptoData& data,
+                    std::vector<uint8>* buffer) {
+  // Due to limitations in the NSS API for the AES-KW algorithm, |data| must be
+  // temporarily viewed as a symmetric key to be wrapped (encrypted).
+  SECItem data_item = MakeSECItemForBuffer(data);
+  crypto::ScopedPK11Slot slot(PK11_GetInternalSlot());
+  crypto::ScopedPK11SymKey data_as_sym_key(PK11_ImportSymKey(slot.get(),
+                                                             CKK_GENERIC_SECRET,
+                                                             PK11_OriginUnwrap,
+                                                             CKA_SIGN,
+                                                             &data_item,
+                                                             NULL));
+  if (!data_as_sym_key)
+    return Status::OperationError();
+
+  return WrapSymKeyAesKw(data_as_sym_key.get(), wrapping_key, buffer);
+}
+
+Status EncryptDecryptAesKw(EncryptOrDecrypt mode,
+                           SymKey* wrapping_key,
+                           const CryptoData& data,
+                           std::vector<uint8>* buffer) {
+  return mode == ENCRYPT ? EncryptAesKw(wrapping_key, data, buffer)
+                         : DecryptAesKw(wrapping_key, data, buffer);
+}
+
+}  // namespace platform
+
+}  // namespace webcrypto
+
+}  // namespace content