Make Nigori method const and keep track of key parameters.

BUG=none
TEST=NigoriTest

Review URL: http://codereview.chromium.org/2637003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@49071 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 17 insertions, 7 deletions

diff --git a/chrome/browser/sync/util/nigori.cc b/chrome/browser/sync/util/nigori.cc
index 03e183d..9334e56 100644
--- a/chrome/browser/sync/util/nigori.cc
+++ b/chrome/browser/sync/util/nigori.cc
@@ -104,7 +104,7 @@ bool Nigori::Init(const std::string& username, const std::string& password) {
 
 // Permute[Kenc,Kmac](type || name)
 bool Nigori::Permute(Type type, const std::string& name,
-                     std::string* permuted) {
+                     std::string* permuted) const {
   DCHECK_LT(0U, name.size());
 
   NigoriStream plaintext;
@@ -147,7 +147,7 @@ std::string GenerateRandomString(size_t size) {
 }
 
 // Enc[Kenc,Kmac](value)
-bool Nigori::Encrypt(const std::string& value, std::string* encrypted) {
+bool Nigori::Encrypt(const std::string& value, std::string* encrypted) const {
   DCHECK_LT(0U, value.size());
 
   std::string iv = GenerateRandomString(kIvSize);
@@ -180,7 +180,7 @@ bool Nigori::Encrypt(const std::string& value, std::string* encrypted) {
   return Base64Encode(output, encrypted);
 }
 
-bool Nigori::Decrypt(const std::string& encrypted, std::string* value) {
+bool Nigori::Decrypt(const std::string& encrypted, std::string* value) const {
   std::string input;
   if (!Base64Decode(encrypted, &input))
     return false;
diff --git a/chrome/browser/sync/util/nigori.h b/chrome/browser/sync/util/nigori.h
index ad57ad7..0050c48 100644
--- a/chrome/browser/sync/util/nigori.h
+++ b/chrome/browser/sync/util/nigori.h
@@ -39,15 +39,22 @@ class Nigori {
   // |username| and |password| are kept constant, a given |type| and |name| pair
   // always yields the same |permuted| value. Note that |permuted| will be
   // Base64 encoded.
-  bool Permute(Type type, const std::string& name, std::string* permuted);
+  bool Permute(Type type, const std::string& name, std::string* permuted) const;
 
   // Encrypts |value|. Note that on success, |encrypted| will be Base64
   // encoded.
-  bool Encrypt(const std::string& value, std::string* encrypted);
+  bool Encrypt(const std::string& value, std::string* encrypted) const;
 
   // Decrypts |value| into |decrypted|. It is assumed that |value| is Base64
   // encoded.
-  bool Decrypt(const std::string& value, std::string* decrypted);
+  bool Decrypt(const std::string& value, std::string* decrypted) const;
+
+  // The next three getters return the parameters used to initialize the keys.
+  // Given the hostname, username and password, another Nigori object capable of
+  // encrypting and decrypting the same data as this one could be initialized.
+  const std::string& hostname() const { return hostname_; }
+  const std::string& username() const { return username_; }
+  const std::string& password() const { return password_; }
 
   static const char kSaltSalt[];  // The salt used to derive the user salt.
   static const size_t kSaltKeySizeInBits = 128;
@@ -61,7 +68,10 @@ class Nigori {
   static const size_t kSigningIterations = 1004;
 
  private:
-  const std::string hostname_;
+  std::string hostname_;
+  std::string username_;
+  std::string password_;
+
   scoped_ptr<base::SymmetricKey> user_key_;
   scoped_ptr<base::SymmetricKey> encryption_key_;
   scoped_ptr<base::SymmetricKey> mac_key_;