html_viewer: Move webcrypto to a place where html_viewer can use it.

content/child/webcrypto/nss/aes_gcm_nss.cc

Index: content/child/webcrypto/nss/aes_gcm_nss.cc
diff --git a/content/child/webcrypto/nss/aes_gcm_nss.cc b/content/child/webcrypto/nss/aes_gcm_nss.cc
deleted file mode 100644
index 27db07c4132f281dfd0af92c3013f74811ffcc3d..0000000000000000000000000000000000000000
--- a/content/child/webcrypto/nss/aes_gcm_nss.cc
+++ /dev/null
@@ -1,186 +0,0 @@
-// 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 "base/numerics/safe_math.h"
-#include "base/stl_util.h"
-#include "content/child/webcrypto/crypto_data.h"
-#include "content/child/webcrypto/nss/aes_algorithm_nss.h"
-#include "content/child/webcrypto/nss/key_nss.h"
-#include "content/child/webcrypto/nss/util_nss.h"
-#include "content/child/webcrypto/status.h"
-#include "content/child/webcrypto/webcrypto_util.h"
-#include "third_party/WebKit/public/platform/WebCryptoAlgorithmParams.h"
-
-// 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.
-//
-// 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 content {
-
-namespace webcrypto {
-
-namespace {
-
-Status NssSupportsAesGcm() {
-  if (NssRuntimeSupport::Get()->IsAesGcmSupported())
-    return Status::Success();
-  return Status::ErrorUnsupported(
-      "NSS version doesn't support AES-GCM. Try using version 3.15 or later");
-}
-
-// 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,
-                            const blink::WebCryptoAlgorithm& algorithm,
-                            const blink::WebCryptoKey& key,
-                            const CryptoData& data,
-                            std::vector<uint8_t>* buffer) {
-  Status status = NssSupportsAesGcm();
-  if (status.IsError())
-    return status;
-
-  PK11SymKey* sym_key = SymKeyNss::Cast(key)->key();
-  const blink::WebCryptoAesGcmParams* params = algorithm.aesGcmParams();
-  if (!params)
-    return Status::ErrorUnexpected();
-
-  unsigned int tag_length_bits;
-  status = GetAesGcmTagLengthInBits(params, &tag_length_bits);
-  if (status.IsError())
-    return status;
-  unsigned int tag_length_bytes = tag_length_bits / 8;
-
-  CryptoData iv(params->iv());
-  CryptoData additional_data(params->optionalAdditionalData());
-
-  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);
-
-  base::CheckedNumeric<unsigned int> buffer_size(data.byte_length());
-
-  // Calculate the output buffer size.
-  if (mode == ENCRYPT) {
-    buffer_size += tag_length_bytes;
-    if (!buffer_size.IsValid())
-      return Status::ErrorDataTooLarge();
-  }
-
-  // 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->resize(buffer_size.ValueOrDie());
-  unsigned char* buffer_data = vector_as_array(buffer);
-
-  PK11_EncryptDecryptFunction encrypt_or_decrypt_func =
-      (mode == ENCRYPT) ? NssRuntimeSupport::Get()->pk11_encrypt_func()
-                        : NssRuntimeSupport::Get()->pk11_decrypt_func();
-
-  unsigned int output_len = 0;
-  SECStatus result = encrypt_or_decrypt_func(
-      sym_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();
-}
-
-class AesGcmImplementation : public AesAlgorithm {
- public:
-  AesGcmImplementation() : AesAlgorithm(CKM_AES_GCM, "GCM") {}
-
-  Status VerifyKeyUsagesBeforeImportKey(
-      blink::WebCryptoKeyFormat format,
-      blink::WebCryptoKeyUsageMask usages) const override {
-    // Prevent importing AES-GCM keys if it is unavailable.
-    Status status = NssSupportsAesGcm();
-    if (status.IsError())
-      return status;
-    return AesAlgorithm::VerifyKeyUsagesBeforeImportKey(format, usages);
-  }
-
-  Status GenerateKey(const blink::WebCryptoAlgorithm& algorithm,
-                     bool extractable,
-                     blink::WebCryptoKeyUsageMask usages,
-                     GenerateKeyResult* result) const override {
-    // Prevent generating AES-GCM keys if it is unavailable.
-    Status status = NssSupportsAesGcm();
-    if (status.IsError())
-      return status;
-
-    return AesAlgorithm::GenerateKey(algorithm, extractable, usages, result);
-  }
-
-  Status Encrypt(const blink::WebCryptoAlgorithm& algorithm,
-                 const blink::WebCryptoKey& key,
-                 const CryptoData& data,
-                 std::vector<uint8_t>* buffer) const override {
-    return AesGcmEncryptDecrypt(ENCRYPT, algorithm, key, data, buffer);
-  }
-
-  Status Decrypt(const blink::WebCryptoAlgorithm& algorithm,
-                 const blink::WebCryptoKey& key,
-                 const CryptoData& data,
-                 std::vector<uint8_t>* buffer) const override {
-    return AesGcmEncryptDecrypt(DECRYPT, algorithm, key, data, buffer);
-  }
-};
-
-}  // namespace
-
-AlgorithmImplementation* CreatePlatformAesGcmImplementation() {
-  return new AesGcmImplementation;
-}
-
-}  // namespace webcrypto
-
-}  // namespace content