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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_
156