crypto/nss_util.h

   1 // Copyright (c) 2012 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 CRYPTO_NSS_UTIL_H_
   6 #define CRYPTO_NSS_UTIL_H_
   7
   8 #include <string>
   9 #include "base/basictypes.h"
  10 #include "crypto/crypto_export.h"
  11
  12 #if defined(USE_NSS)
  13 class FilePath;
  14 #endif  // defined(USE_NSS)
  15
  16 namespace base {
  17 class Lock;
  18 class Time;
  19 }  // namespace base
  20
  21 // This file specifically doesn't depend on any NSS or NSPR headers because it
  22 // is included by various (non-crypto) parts of chrome to call the
  23 // initialization functions.
  24 namespace crypto {
  25
  26 class SymmetricKey;
  27
  28 #if defined(USE_NSS)
  29 // EarlySetupForNSSInit performs lightweight setup which must occur before the
  30 // process goes multithreaded. This does not initialise NSS. For test, see
  31 // EnsureNSSInit.
  32 CRYPTO_EXPORT void EarlySetupForNSSInit();
  33 #endif
  34
  35 // Initialize NRPR if it isn't already initialized.  This function is
  36 // thread-safe, and NSPR will only ever be initialized once.
  37 CRYPTO_EXPORT void EnsureNSPRInit();
  38
  39 // Initialize NSS safely for strict sandboxing.  This function makes sure that
  40 // NSS is initialized safely and will have proper entropy in a restricted,
  41 // sandboxed environment.
  42 //
  43 // As a defense in depth measure, this function should be called in a sandboxed
  44 // environment to make sure NSS will not load security modules that could
  45 // expose private data and keys.  Make sure to get an LGTM from Security
  46 // if you use this.
  47 CRYPTO_EXPORT void WarmUpNSSSafely();
  48
  49 // Initialize NSS if it isn't already initialized.  This must be called before
  50 // any other NSS functions.  This function is thread-safe, and NSS will only
  51 // ever be initialized once.
  52 CRYPTO_EXPORT void EnsureNSSInit();
  53
  54 // Call this before calling EnsureNSSInit() will force NSS to initialize
  55 // without a persistent DB.  This is used for the special case where access of
  56 // persistent DB is prohibited.
  57 //
  58 // TODO(hclam): Isolate loading default root certs.
  59 //
  60 // NSS will be initialized without loading any user security modules, including
  61 // the built-in root certificates module. User security modules need to be
  62 // loaded manually after NSS initialization.
  63 //
  64 // If EnsureNSSInit() is called before then this function has no effect.
  65 //
  66 // Calling this method only has effect on Linux.
  67 //
  68 // WARNING: Use this with caution.
  69 CRYPTO_EXPORT void ForceNSSNoDBInit();
  70
  71 // This method is used to disable checks in NSS when used in a forked process.
  72 // NSS checks whether it is running a forked process to avoid problems when
  73 // using user security modules in a forked process.  However if we are sure
  74 // there are no modules loaded before the process is forked then there is no
  75 // harm disabling the check.
  76 //
  77 // This method must be called before EnsureNSSInit() to take effect.
  78 //
  79 // WARNING: Use this with caution.
  80 CRYPTO_EXPORT void DisableNSSForkCheck();
  81
  82 // Load NSS library files. This function has no effect on Mac and Windows.
  83 // This loads the necessary NSS library files so that NSS can be initialized
  84 // after loading additional library files is disallowed, for example when the
  85 // sandbox is active.
  86 //
  87 // Note that this does not load libnssckbi.so which contains the root
  88 // certificates.
  89 CRYPTO_EXPORT void LoadNSSLibraries();
  90
  91 // Check if the current NSS version is greater than or equals to |version|.
  92 // A sample version string is "3.12.3".
  93 bool CheckNSSVersion(const char* version);
  94
  95 #if defined(OS_CHROMEOS)
  96 // Open the r/w nssdb that's stored inside the user's encrypted home
  97 // directory.  This is the default slot returned by
  98 // GetPublicNSSKeySlot().
  99 CRYPTO_EXPORT void OpenPersistentNSSDB();
 100
 101 // Indicates that NSS should load the Chaps library so that we
 102 // can access the TPM through NSS.  Once this is called,
 103 // GetPrivateNSSKeySlot() will return the TPM slot if one was found.
 104 CRYPTO_EXPORT void EnableTPMTokenForNSS();
 105
 106 // Get name and user PIN for the built-in TPM token on ChromeOS.
 107 // Either one can safely be NULL.  Should only be called after
 108 // EnableTPMTokenForNSS has been called with a non-null delegate.
 109 CRYPTO_EXPORT void GetTPMTokenInfo(std::string* token_name,
 110                                    std::string* user_pin);
 111
 112 // Returns true if the TPM is owned and PKCS#11 initialized with the
 113 // user and security officer PINs, and has been enabled in NSS by
 114 // calling EnableTPMForNSS, and Chaps has been successfully
 115 // loaded into NSS.
 116 CRYPTO_EXPORT bool IsTPMTokenReady();
 117
 118 // Initialize the TPM token.  Does nothing if it is already initialized.
 119 CRYPTO_EXPORT bool InitializeTPMToken(const std::string& token_name,
 120                                       const std::string& user_pin);
 121
 122 // Gets supplemental user key. Creates one in NSS database if it does not exist.
 123 // The supplemental user key is used for AES encryption of user data that is
 124 // stored and protected by cryptohome. This additional layer of encryption of
 125 // provided to ensure that sensitive data wouldn't be exposed in plain text in
 126 // case when an attacker would somehow gain access to all content within
 127 // cryptohome.
 128 CRYPTO_EXPORT SymmetricKey* GetSupplementalUserKey();
 129 #endif
 130
 131 // Convert a NSS PRTime value into a base::Time object.
 132 // We use a int64 instead of PRTime here to avoid depending on NSPR headers.
 133 CRYPTO_EXPORT base::Time PRTimeToBaseTime(int64 prtime);
 134
 135 // Convert a base::Time object into a PRTime value.
 136 // We use a int64 instead of PRTime here to avoid depending on NSPR headers.
 137 CRYPTO_EXPORT int64 BaseTimeToPRTime(base::Time time);
 138
 139 #if defined(USE_NSS)
 140 // Exposed for unittests only.
 141 // TODO(mattm): When NSS 3.14 is the minimum version required,
 142 // switch back to using a separate user DB for each test.
 143 // Because of https://bugzilla.mozilla.org/show_bug.cgi?id=588269 , the
 144 // opened user DB is not automatically closed.
 145 class CRYPTO_EXPORT_PRIVATE ScopedTestNSSDB {
 146  public:
 147   ScopedTestNSSDB();
 148   ~ScopedTestNSSDB();
 149
 150   bool is_open() { return is_open_; }
 151
 152  private:
 153   bool is_open_;
 154   DISALLOW_COPY_AND_ASSIGN(ScopedTestNSSDB);
 155 };
 156
 157 // NSS has a bug which can cause a deadlock or stall in some cases when writing
 158 // to the certDB and keyDB. It also has a bug which causes concurrent key pair
 159 // generations to scribble over each other. To work around this, we synchronize
 160 // writes to the NSS databases with a global lock. The lock is hidden beneath a
 161 // function for easy disabling when the bug is fixed. Callers should allow for
 162 // it to return NULL in the future.
 163 //
 164 // See https://bugzilla.mozilla.org/show_bug.cgi?id=564011
 165 base::Lock* GetNSSWriteLock();
 166
 167 // A helper class that acquires the NSS write Lock while the AutoNSSWriteLock
 168 // is in scope.
 169 class CRYPTO_EXPORT AutoNSSWriteLock {
 170  public:
 171   AutoNSSWriteLock();
 172   ~AutoNSSWriteLock();
 173  private:
 174   base::Lock *lock_;
 175   DISALLOW_COPY_AND_ASSIGN(AutoNSSWriteLock);
 176 };
 177
 178 #endif  // defined(USE_NSS)
 179
 180 }  // namespace crypto
 181
 182 #endif  // CRYPTO_NSS_UTIL_H_