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

content/child/webcrypto/openssl/aes_ctr_openssl.cc

Index: content/child/webcrypto/openssl/aes_ctr_openssl.cc
diff --git a/content/child/webcrypto/openssl/aes_ctr_openssl.cc b/content/child/webcrypto/openssl/aes_ctr_openssl.cc
deleted file mode 100644
index 89e99eebd156eb411e4cb5c320264fbfcfb10037..0000000000000000000000000000000000000000
--- a/content/child/webcrypto/openssl/aes_ctr_openssl.cc
+++ /dev/null
@@ -1,272 +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 <openssl/aes.h>
-#include <openssl/evp.h>
-
-#include "base/logging.h"
-#include "base/macros.h"
-#include "base/numerics/safe_math.h"
-#include "base/stl_util.h"
-#include "content/child/webcrypto/crypto_data.h"
-#include "content/child/webcrypto/openssl/aes_algorithm_openssl.h"
-#include "content/child/webcrypto/openssl/key_openssl.h"
-#include "content/child/webcrypto/openssl/util_openssl.h"
-#include "content/child/webcrypto/status.h"
-#include "content/child/webcrypto/webcrypto_util.h"
-#include "crypto/openssl_util.h"
-#include "crypto/scoped_openssl_types.h"
-#include "third_party/WebKit/public/platform/WebCryptoAlgorithmParams.h"
-
-namespace content {
-
-namespace webcrypto {
-
-namespace {
-
-const EVP_CIPHER* GetAESCipherByKeyLength(unsigned int key_length_bytes) {
-  // BoringSSL does not support 192-bit AES keys.
-  switch (key_length_bytes) {
-    case 16:
-      return EVP_aes_128_ctr();
-    case 32:
-      return EVP_aes_256_ctr();
-    default:
-      return NULL;
-  }
-}
-
-// Encrypts/decrypts given a 128-bit counter.
-//
-// |output| must be a pointer to a buffer which has a length of at least
-// |input.byte_length()|.
-Status AesCtrEncrypt128BitCounter(const EVP_CIPHER* cipher,
-                                  const CryptoData& raw_key,
-                                  const CryptoData& input,
-                                  const CryptoData& counter,
-                                  uint8_t* output) {
-  DCHECK(cipher);
-  DCHECK_EQ(16u, counter.byte_length());
-
-  crypto::OpenSSLErrStackTracer err_tracer(FROM_HERE);
-  crypto::ScopedOpenSSL<EVP_CIPHER_CTX, EVP_CIPHER_CTX_free> context(
-      EVP_CIPHER_CTX_new());
-
-  if (!context.get())
-    return Status::OperationError();
-
-  if (!EVP_CipherInit_ex(context.get(), cipher, NULL, raw_key.bytes(),
-                         counter.bytes(), ENCRYPT)) {
-    return Status::OperationError();
-  }
-
-  int output_len = 0;
-  if (!EVP_CipherUpdate(context.get(), output, &output_len, input.bytes(),
-                        input.byte_length())) {
-    return Status::OperationError();
-  }
-  int final_output_chunk_len = 0;
-  if (!EVP_CipherFinal_ex(context.get(), output + output_len,
-                          &final_output_chunk_len)) {
-    return Status::OperationError();
-  }
-
-  output_len += final_output_chunk_len;
-  if (static_cast<unsigned int>(output_len) != input.byte_length())
-    return Status::ErrorUnexpected();
-
-  return Status::Success();
-}
-
-// Returns ceil(a/b), where a and b are integers.
-template <typename T>
-T CeilDiv(T a, T b) {
-  return a == 0 ? 0 : 1 + (a - 1) / b;
-}
-
-// Extracts the counter as a BIGNUM. The counter is the rightmost
-// "counter_length_bits" of the block, interpreted as a big-endian number.
-crypto::ScopedBIGNUM GetCounter(const CryptoData& counter_block,
-                                unsigned int counter_length_bits) {
-  unsigned int counter_length_remainder_bits = (counter_length_bits % 8);
-
-  // If the counter is a multiple of 8 bits then can call BN_bin2bn() directly.
-  if (counter_length_remainder_bits == 0) {
-    unsigned int byte_length = counter_length_bits / 8;
-    return crypto::ScopedBIGNUM(BN_bin2bn(
-        counter_block.bytes() + counter_block.byte_length() - byte_length,
-        byte_length, NULL));
-  }
-
-  // Otherwise make a copy of the counter and zero out the topmost bits so
-  // BN_bin2bn() can be called with a byte stream.
-  unsigned int byte_length = CeilDiv(counter_length_bits, 8u);
-  std::vector<uint8_t> counter(
-      counter_block.bytes() + counter_block.byte_length() - byte_length,
-      counter_block.bytes() + counter_block.byte_length());
-  counter[0] &= ~(0xFF << counter_length_remainder_bits);
-
-  return crypto::ScopedBIGNUM(
-      BN_bin2bn(vector_as_array(&counter), counter.size(), NULL));
-}
-
-// Returns a counter block with the counter bits all set all zero.
-std::vector<uint8_t> BlockWithZeroedCounter(const CryptoData& counter_block,
-                                            unsigned int counter_length_bits) {
-  unsigned int counter_length_bytes = counter_length_bits / 8;
-  unsigned int counter_length_bits_remainder = counter_length_bits % 8;
-
-  std::vector<uint8_t> new_counter_block(
-      counter_block.bytes(),
-      counter_block.bytes() + counter_block.byte_length());
-
-  unsigned int index = new_counter_block.size() - counter_length_bytes;
-  memset(&new_counter_block.front() + index, 0, counter_length_bytes);
-
-  if (counter_length_bits_remainder) {
-    new_counter_block[index - 1] &= 0xFF << counter_length_bits_remainder;
-  }
-
-  return new_counter_block;
-}
-
-// This function does encryption/decryption for AES-CTR (encryption and
-// decryption are the same).
-//
-// BoringSSL's interface for AES-CTR differs from that of WebCrypto. In
-// WebCrypto the caller specifies a 16-byte counter block and designates how
-// many of the right-most X bits to use as a big-endian counter. Whereas in
-// BoringSSL the entire counter block is interpreted as a 128-bit counter.
-//
-// In AES-CTR, the counter block MUST be unique across all messages that are
-// encrypted/decrypted. WebCrypto expects that the counter can start at any
-// value, and is therefore permitted to wrap around to zero on overflow.
-//
-// Some care is taken to fail if the counter wraps back to an earlier value.
-// However this protection is only enforced during a *single* call to
-// encrypt/decrypt.
-Status AesCtrEncryptDecrypt(const blink::WebCryptoAlgorithm& algorithm,
-                            const blink::WebCryptoKey& key,
-                            const CryptoData& data,
-                            std::vector<uint8_t>* buffer) {
-  const blink::WebCryptoAesCtrParams* params = algorithm.aesCtrParams();
-  const std::vector<uint8_t>& raw_key =
-      SymKeyOpenSsl::Cast(key)->raw_key_data();
-
-  if (params->counter().size() != 16)
-    return Status::ErrorIncorrectSizeAesCtrCounter();
-
-  unsigned int counter_length_bits = params->lengthBits();
-  if (counter_length_bits < 1 || counter_length_bits > 128)
-    return Status::ErrorInvalidAesCtrCounterLength();
-
-  // The output of AES-CTR is the same size as the input. However BoringSSL
-  // expects buffer sizes as an "int".
-  base::CheckedNumeric<int> output_max_len = data.byte_length();
-  if (!output_max_len.IsValid())
-    return Status::ErrorDataTooLarge();
-
-  const EVP_CIPHER* const cipher = GetAESCipherByKeyLength(raw_key.size());
-  if (!cipher)
-    return Status::ErrorUnexpected();
-
-  const CryptoData counter_block(params->counter());
-  buffer->resize(output_max_len.ValueOrDie());
-
-  // The total number of possible counter values is pow(2, counter_length_bits)
-  crypto::ScopedBIGNUM num_counter_values(BN_new());
-  if (!BN_lshift(num_counter_values.get(), BN_value_one(), counter_length_bits))
-    return Status::ErrorUnexpected();
-
-  crypto::ScopedBIGNUM current_counter =
-      GetCounter(counter_block, counter_length_bits);
-
-  // The number of AES blocks needed for encryption/decryption. The counter is
-  // incremented this many times.
-  crypto::ScopedBIGNUM num_output_blocks(BN_new());
-  if (!BN_set_word(
-          num_output_blocks.get(),
-          CeilDiv(buffer->size(), static_cast<size_t>(AES_BLOCK_SIZE)))) {
-    return Status::ErrorUnexpected();
-  }
-
-  // If the counter is going to be incremented more times than there are counter
-  // values, fail. (Repeating values of the counter block is bad).
-  if (BN_cmp(num_output_blocks.get(), num_counter_values.get()) > 0)
-    return Status::ErrorAesCtrInputTooLongCounterRepeated();
-
-  // This is the number of blocks that can be successfully encrypted without
-  // overflowing the counter. Encrypting the subsequent block will need to
-  // reset the counter to zero.
-  crypto::ScopedBIGNUM num_blocks_until_reset(BN_new());
-
-  if (!BN_sub(num_blocks_until_reset.get(), num_counter_values.get(),
-              current_counter.get())) {
-    return Status::ErrorUnexpected();
-  }
-
-  // If the counter can be incremented for the entire input without
-  // wrapping-around, do it as a single call into BoringSSL.
-  if (BN_cmp(num_blocks_until_reset.get(), num_output_blocks.get()) >= 0) {
-    return AesCtrEncrypt128BitCounter(cipher, CryptoData(raw_key), data,
-                                      counter_block, vector_as_array(buffer));
-  }
-
-  // Otherwise the encryption needs to be done in 2 parts. The first part using
-  // the current counter_block, and the next part resetting the counter portion
-  // of the block to zero.
-
-  // This is guaranteed to fit in an "unsigned int" because input size in bytes
-  // fits in an "unsigned int".
-  BN_ULONG num_blocks_part1 = BN_get_word(num_blocks_until_reset.get());
-  BN_ULONG input_size_part1 = num_blocks_part1 * AES_BLOCK_SIZE;
-  DCHECK_LT(input_size_part1, data.byte_length());
-
-  // Encrypt the first part (before wrap-around).
-  Status status = AesCtrEncrypt128BitCounter(
-      cipher, CryptoData(raw_key), CryptoData(data.bytes(), input_size_part1),
-      counter_block, vector_as_array(buffer));
-  if (status.IsError())
-    return status;
-
-  // Encrypt the second part (after wrap-around).
-  std::vector<uint8_t> counter_block_part2 =
-      BlockWithZeroedCounter(counter_block, counter_length_bits);
-
-  return AesCtrEncrypt128BitCounter(
-      cipher, CryptoData(raw_key),
-      CryptoData(data.bytes() + input_size_part1,
-                 data.byte_length() - input_size_part1),
-      CryptoData(counter_block_part2),
-      vector_as_array(buffer) + input_size_part1);
-}
-
-class AesCtrImplementation : public AesAlgorithm {
- public:
-  AesCtrImplementation() : AesAlgorithm("CTR") {}
-
-  Status Encrypt(const blink::WebCryptoAlgorithm& algorithm,
-                 const blink::WebCryptoKey& key,
-                 const CryptoData& data,
-                 std::vector<uint8_t>* buffer) const override {
-    return AesCtrEncryptDecrypt(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 AesCtrEncryptDecrypt(algorithm, key, data, buffer);
-  }
-};
-
-}  // namespace
-
-AlgorithmImplementation* CreatePlatformAesCtrImplementation() {
-  return new AesCtrImplementation;
-}
-
-}  // namespace webcrypto
-
-}  // namespace content