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