SymmetricKey::GetRawKey/key are now const methods.

instance and should have been const. Making this change also allowed
for several other methods to pass const SymmetricKey pointers where
previously they were non-const.

SymmetricKey: :GetRawKey() and SymmetricKey::key() did not modify the
Change-Id: I937e477f91870a1026c2c0aaf767a2e7d5e0ed42
Reviewed-on: https://chromium-review.googlesource.com/529746Reviewed-by: Adam Langley <agl@chromium.org>
Reviewed-by: Luke Halliwell <halliwell@chromium.org>
Reviewed-by: Xiaohan Wang <xhwang@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Chris Mumford <cmumford@chromium.org>
Cr-Commit-Position: refs/heads/master@{#478693}

chrome/browser/chromeos/settings/token_encryptor.cc

@@ -75,7 +75,7 @@ std::unique_ptr<crypto::SymmetricKey> CryptohomeTokenEncryptor::PassphraseToKey(
 }
 
 std::string CryptohomeTokenEncryptor::EncryptTokenWithKey(
-    crypto::SymmetricKey* key,
+    const crypto::SymmetricKey* key,
     const std::string& salt,
     const std::string& token) {
   crypto::Encryptor encryptor;
@@ -97,7 +97,7 @@ std::string CryptohomeTokenEncryptor::EncryptTokenWithKey(
 }
 
 std::string CryptohomeTokenEncryptor::DecryptTokenWithKey(
-    crypto::SymmetricKey* key,
+    const crypto::SymmetricKey* key,
     const std::string& salt,
     const std::string& encrypted_token_hex) {
   std::vector<uint8_t> encrypted_token_bytes;

chrome/browser/chromeos/settings/token_encryptor.h

@@ -52,12 +52,12 @@ class CryptohomeTokenEncryptor : public TokenEncryptor {
       const std::string& salt);
 
   // Encrypts (AES) the token given |key| and |salt|.
-  std::string EncryptTokenWithKey(crypto::SymmetricKey* key,
+  std::string EncryptTokenWithKey(const crypto::SymmetricKey* key,
                                   const std::string& salt,
                                   const std::string& token);
 
   // Decrypts (AES) hex encoded encrypted token given |key| and |salt|.
-  std::string DecryptTokenWithKey(crypto::SymmetricKey* key,
+  std::string DecryptTokenWithKey(const crypto::SymmetricKey* key,
                                   const std::string& salt,
                                   const std::string& encrypted_token_hex);
 

chromecast/media/base/decrypt_context_impl_clearkey.cc

@@ -20,7 +20,7 @@ namespace chromecast {
 namespace media {
 
 DecryptContextImplClearKey::DecryptContextImplClearKey(
-    crypto::SymmetricKey* key)
+    const crypto::SymmetricKey* key)
     : DecryptContextImpl(KEY_SYSTEM_CLEAR_KEY), key_(key) {
   CHECK(key);
 }

chromecast/media/base/decrypt_context_impl_clearkey.h

@@ -22,7 +22,7 @@ namespace media {
 class DecryptContextImplClearKey : public DecryptContextImpl {
  public:
   // Note: DecryptContextClearKey does not take ownership of |key|.
-  explicit DecryptContextImplClearKey(crypto::SymmetricKey* key);
+  explicit DecryptContextImplClearKey(const crypto::SymmetricKey* key);
   ~DecryptContextImplClearKey() override;
 
   // DecryptContextImpl implementation.
@@ -37,7 +37,7 @@ class DecryptContextImplClearKey : public DecryptContextImpl {
   bool DoDecrypt(CastDecoderBuffer* buffer,
                  uint8_t* output,
                  size_t data_offset);
-  crypto::SymmetricKey* const key_;
+  const crypto::SymmetricKey* const key_;
 
   DISALLOW_COPY_AND_ASSIGN(DecryptContextImplClearKey);
 };

crypto/encryptor.cc

@@ -19,7 +19,7 @@ namespace crypto {
 
 namespace {
 
-const EVP_CIPHER* GetCipherForKey(SymmetricKey* key) {
+const EVP_CIPHER* GetCipherForKey(const SymmetricKey* key) {
   switch (key->key().length()) {
     case 16: return EVP_aes_128_cbc();
     case 32: return EVP_aes_256_cbc();
@@ -90,7 +90,7 @@ Encryptor::Encryptor() : key_(nullptr), mode_(CBC) {}
 Encryptor::~Encryptor() {
 }
 
-bool Encryptor::Init(SymmetricKey* key,
+bool Encryptor::Init(const SymmetricKey* key,
                      Mode mode,
                      const base::StringPiece& iv) {
   DCHECK(key);

crypto/encryptor.h

@@ -58,7 +58,7 @@ class CRYPTO_EXPORT Encryptor {
   //
   // If |mode| is CBC, |iv| must not be empty; if it is CTR, then |iv| must be
   // empty.
-  bool Init(SymmetricKey* key, Mode mode, const base::StringPiece& iv);
+  bool Init(const SymmetricKey* key, Mode mode, const base::StringPiece& iv);
 
   // Encrypts |plaintext| into |ciphertext|.  |plaintext| may only be empty if
   // the mode is CBC.
@@ -84,7 +84,7 @@ class CRYPTO_EXPORT Encryptor {
   // TODO(albertb): Support streaming encryption.
 
  private:
-  SymmetricKey* key_;
+  const SymmetricKey* key_;
   Mode mode_;
   std::unique_ptr<Counter> counter_;
 

crypto/hmac.cc

@@ -49,7 +49,7 @@ bool HMAC::Init(const unsigned char* key, size_t key_length) {
   return true;
 }
 
-bool HMAC::Init(SymmetricKey* key) {
+bool HMAC::Init(const SymmetricKey* key) {
   std::string raw_key;
   bool result = key->GetRawKey(&raw_key) && Init(raw_key);
   // Zero out key copy.  This might get optimized away, but one can hope.

crypto/hmac.h

@@ -53,7 +53,7 @@ class CRYPTO_EXPORT HMAC {
 
   // Initializes this instance using |key|. Call Init
   // only once. It returns false on the second or later calls.
-  bool Init(SymmetricKey* key) WARN_UNUSED_RESULT;
+  bool Init(const SymmetricKey* key) WARN_UNUSED_RESULT;
 
   // Initializes this instance using |key|. Call Init only once. It returns
   // false on the second or later calls.

crypto/symmetric_key.cc

@@ -100,7 +100,7 @@ std::unique_ptr<SymmetricKey> SymmetricKey::Import(Algorithm algorithm,
   return key;
 }
 
-bool SymmetricKey::GetRawKey(std::string* raw_key) {
+bool SymmetricKey::GetRawKey(std::string* raw_key) const {
   *raw_key = key_;
   return true;
 }

crypto/symmetric_key.h

@@ -55,12 +55,12 @@ class CRYPTO_EXPORT SymmetricKey {
   static std::unique_ptr<SymmetricKey> Import(Algorithm algorithm,
                                               const std::string& raw_key);
 
-  const std::string& key() { return key_; }
+  const std::string& key() const { return key_; }
 
   // Extracts the raw key from the platform specific data.
   // Warning: |raw_key| holds the raw key as bytes and thus must be handled
   // carefully.
-  bool GetRawKey(std::string* raw_key);
+  bool GetRawKey(std::string* raw_key) const;
 
  private:
   SymmetricKey();

media/cdm/aes_decryptor.cc

@@ -172,8 +172,9 @@ static void CopySubsamples(const std::vector<SubsampleEntry>& subsamples,
 
 // Decrypts |input| using |key|.  Returns a DecoderBuffer with the decrypted
 // data if decryption succeeded or NULL if decryption failed.
-static scoped_refptr<DecoderBuffer> DecryptData(const DecoderBuffer& input,
-                                                crypto::SymmetricKey* key) {
+static scoped_refptr<DecoderBuffer> DecryptData(
+    const DecoderBuffer& input,
+    const crypto::SymmetricKey* key) {
   CHECK(input.data_size());
   CHECK(input.decrypt_config());
   CHECK(key);