1 // Copyright 2014 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef CHROME_BROWSER_PREFS_PREF_HASH_STORE_TRANSACTION_H_ 6 #define CHROME_BROWSER_PREFS_PREF_HASH_STORE_TRANSACTION_H_ 7 8 #include <string> 9 #include <vector> 10 11 namespace base { 12 class DictionaryValue; 13 class Value; 14 } // namespace base 15 16 // Used to perform a series of checks/transformations on a PrefHashStore. 17 class PrefHashStoreTransaction { 18 public: 19 enum ValueState { 20 // The preference value corresponds to its stored hash. 21 UNCHANGED, 22 // The preference has been cleared since the last hash. 23 CLEARED, 24 // The preference value corresponds to its stored hash, which was calculated 25 // using a deprecated hash algorithm which isn't as safe as the current one. 26 WEAK_LEGACY, 27 // The preference value corresponds to its stored hash, but the hash was 28 // calculated using a deprecated hash algorithm which is just as safe as 29 // the current one. 30 SECURE_LEGACY, 31 // The preference value has been changed since the last hash. 32 CHANGED, 33 // No stored hash exists for the preference value. 34 UNTRUSTED_UNKNOWN_VALUE, 35 // No stored hash exists for the preference value, but the current set of 36 // hashes stored is trusted and thus this value can safely be seeded. This 37 // happens when all hashes are already properly seeded and a newly 38 // tracked value needs to be seeded). NULL values are inherently trusted as 39 // well. 40 TRUSTED_UNKNOWN_VALUE, 41 }; 42 43 // Finalizes any remaining work after the transaction has been performed. ~PrefHashStoreTransaction()44 virtual ~PrefHashStoreTransaction() {} 45 46 // Checks |initial_value| against the existing stored value hash. 47 virtual ValueState CheckValue( 48 const std::string& path, const base::Value* initial_value) const = 0; 49 50 // Stores a hash of the current |value| of the preference at |path|. 51 virtual void StoreHash(const std::string& path, 52 const base::Value* value) = 0; 53 54 // Checks |initial_value| against the existing stored hashes for the split 55 // preference at |path|. |initial_split_value| being an empty dictionary or 56 // NULL is equivalent. |invalid_keys| must initially be empty. |invalid_keys| 57 // will not be modified unless the return value is CHANGED, in which case it 58 // will be filled with the keys that are considered invalid (unknown or 59 // changed). 60 virtual ValueState CheckSplitValue( 61 const std::string& path, 62 const base::DictionaryValue* initial_split_value, 63 std::vector<std::string>* invalid_keys) const = 0; 64 65 // Stores hashes for the |value| of the split preference at |path|. 66 // |split_value| being an empty dictionary or NULL is equivalent. 67 virtual void StoreSplitHash( 68 const std::string& path, 69 const base::DictionaryValue* split_value) = 0; 70 71 // Indicates whether the store contains a hash for the preference at |path|. 72 virtual bool HasHash(const std::string& path) const = 0; 73 74 // Sets the hash for the preference at |path|. 75 // If |path| is a split preference |hash| must be a DictionaryValue whose 76 // keys are keys in the split preference and whose values are MACs of the 77 // corresponding values in the split preference. 78 // If |path| is an atomic preference |hash| must be a StringValue 79 // containing a MAC of the preference value. 80 // |hash| should originate from a PrefHashStore sharing the same MAC 81 // parameters as this transaction's store. 82 // The (in)validity of the super MAC will be maintained by this call. 83 virtual void ImportHash(const std::string& path, const base::Value* hash) = 0; 84 85 // Removes the hash stored at |path|. The (in)validity of the super MAC will 86 // be maintained by this call. 87 virtual void ClearHash(const std::string& path) = 0; 88 89 // Indicates whether the super MAC was successfully verified at the beginning 90 // of this transaction. 91 virtual bool IsSuperMACValid() const = 0; 92 93 // Forces a valid super MAC to be stored when this transaction terminates. 94 // Returns true if this results in a change to the store contents. 95 virtual bool StampSuperMac() = 0; 96 }; 97 98 #endif // CHROME_BROWSER_PREFS_PREF_HASH_STORE_TRANSACTION_H_ 99