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