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 "base/callback.h"
  11 #include "base/compiler_specific.h"
  12 #include "crypto/crypto_export.h"
  13
  14 namespace base {
  15 class FilePath;
  16 class Lock;
  17 class Time;
  18 }  // namespace base
  19
  20 // This file specifically doesn't depend on any NSS or NSPR headers because it
  21 // is included by various (non-crypto) parts of chrome to call the
  22 // initialization functions.
  23 namespace crypto {
  24
  25 #if defined(USE_NSS)
  26 // EarlySetupForNSSInit performs lightweight setup which must occur before the
  27 // process goes multithreaded. This does not initialise NSS. For test, see
  28 // EnsureNSSInit.
  29 CRYPTO_EXPORT void EarlySetupForNSSInit();
  30 #endif
  31
  32 // Initialize NRPR if it isn't already initialized.  This function is
  33 // thread-safe, and NSPR will only ever be initialized once.
  34 CRYPTO_EXPORT void EnsureNSPRInit();
  35
  36 // Initialize NSS safely for strict sandboxing.  This function tells NSS to not
  37 // load user security modules, and makes sure NSS will have proper entropy in a
  38 // restricted, sandboxed environment.
  39 //
  40 // As a defense in depth measure, this function should be called in a sandboxed
  41 // environment.  That way, in the event of a bug, NSS will still not be able to
  42 // load security modules that could expose private data and keys.
  43 //
  44 // Make sure to get an LGTM from the Chrome Security Team if you use this.
  45 CRYPTO_EXPORT void InitNSSSafely();
  46
  47 // Initialize NSS if it isn't already initialized.  This must be called before
  48 // any other NSS functions.  This function is thread-safe, and NSS will only
  49 // ever be initialized once.
  50 CRYPTO_EXPORT void EnsureNSSInit();
  51
  52 // Call this before calling EnsureNSSInit() will force NSS to initialize
  53 // without a persistent DB.  This is used for the special case where access of
  54 // persistent DB is prohibited.
  55 //
  56 // TODO(hclam): Isolate loading default root certs.
  57 //
  58 // NSS will be initialized without loading any user security modules, including
  59 // the built-in root certificates module. User security modules need to be
  60 // loaded manually after NSS initialization.
  61 //
  62 // If EnsureNSSInit() is called before then this function has no effect.
  63 //
  64 // Calling this method only has effect on Linux.
  65 //
  66 // WARNING: Use this with caution.
  67 CRYPTO_EXPORT void ForceNSSNoDBInit();
  68
  69 // This method is used to disable checks in NSS when used in a forked process.
  70 // NSS checks whether it is running a forked process to avoid problems when
  71 // using user security modules in a forked process.  However if we are sure
  72 // there are no modules loaded before the process is forked then there is no
  73 // harm disabling the check.
  74 //
  75 // This method must be called before EnsureNSSInit() to take effect.
  76 //
  77 // WARNING: Use this with caution.
  78 CRYPTO_EXPORT void DisableNSSForkCheck();
  79
  80 // Load NSS library files. This function has no effect on Mac and Windows.
  81 // This loads the necessary NSS library files so that NSS can be initialized
  82 // after loading additional library files is disallowed, for example when the
  83 // sandbox is active.
  84 //
  85 // Note that this does not load libnssckbi.so which contains the root
  86 // certificates.
  87 CRYPTO_EXPORT void LoadNSSLibraries();
  88
  89 // Check if the current NSS version is greater than or equals to |version|.
  90 // A sample version string is "3.12.3".
  91 bool CheckNSSVersion(const char* version);
  92
  93 #if defined(OS_CHROMEOS)
  94 // Indicates that NSS should use the Chaps library so that we
  95 // can access the TPM through NSS.  InitializeTPMTokenAndSystemSlot and
  96 // InitializeTPMForChromeOSUser must still be called to load the slots.
  97 CRYPTO_EXPORT void EnableTPMTokenForNSS();
  98
  99 // Returns true if EnableTPMTokenForNSS has been called.
 100 CRYPTO_EXPORT bool IsTPMTokenEnabledForNSS();
 101
 102 // Returns true if the TPM is owned and PKCS#11 initialized with the
 103 // user and security officer PINs, and has been enabled in NSS by
 104 // calling EnableTPMForNSS, and Chaps has been successfully
 105 // loaded into NSS.
 106 // If |callback| is non-null and the function returns false, the |callback| will
 107 // be run once the TPM is ready. |callback| will never be run if the function
 108 // returns true.
 109 CRYPTO_EXPORT bool IsTPMTokenReady(const base::Closure& callback)
 110     WARN_UNUSED_RESULT;
 111
 112 // Initialize the TPM token and system slot. The |callback| will run on the same
 113 // thread with true if the token and slot were successfully loaded or were
 114 // already initialized. |callback| will be passed false if loading failed.  Once
 115 // called, InitializeTPMTokenAndSystemSlot must not be called again until the
 116 // |callback| has been run.
 117 CRYPTO_EXPORT void InitializeTPMTokenAndSystemSlot(
 118     int system_slot_id,
 119     const base::Callback<void(bool)>& callback);
 120 #endif
 121
 122 // Convert a NSS PRTime value into a base::Time object.
 123 // We use a int64 instead of PRTime here to avoid depending on NSPR headers.
 124 CRYPTO_EXPORT base::Time PRTimeToBaseTime(int64 prtime);
 125
 126 // Convert a base::Time object into a PRTime value.
 127 // We use a int64 instead of PRTime here to avoid depending on NSPR headers.
 128 CRYPTO_EXPORT int64 BaseTimeToPRTime(base::Time time);
 129
 130 #if defined(USE_NSS)
 131 // NSS has a bug which can cause a deadlock or stall in some cases when writing
 132 // to the certDB and keyDB. It also has a bug which causes concurrent key pair
 133 // generations to scribble over each other. To work around this, we synchronize
 134 // writes to the NSS databases with a global lock. The lock is hidden beneath a
 135 // function for easy disabling when the bug is fixed. Callers should allow for
 136 // it to return NULL in the future.
 137 //
 138 // See https://bugzilla.mozilla.org/show_bug.cgi?id=564011
 139 base::Lock* GetNSSWriteLock();
 140
 141 // A helper class that acquires the NSS write Lock while the AutoNSSWriteLock
 142 // is in scope.
 143 class CRYPTO_EXPORT AutoNSSWriteLock {
 144  public:
 145   AutoNSSWriteLock();
 146   ~AutoNSSWriteLock();
 147  private:
 148   base::Lock *lock_;
 149   DISALLOW_COPY_AND_ASSIGN(AutoNSSWriteLock);
 150 };
 151 #endif  // defined(USE_NSS)
 152
 153 }  // namespace crypto
 154
 155 #endif  // CRYPTO_NSS_UTIL_H_