1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
3 /* This code is made available to you under your choice of the following sets
4  * of licensing terms:
5  */
6 /* This Source Code Form is subject to the terms of the Mozilla Public
7  * License, v. 2.0. If a copy of the MPL was not distributed with this
8  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
9  */
10 /* Copyright 2014 Mozilla Contributors
11  *
12  * Licensed under the Apache License, Version 2.0 (the "License");
13  * you may not use this file except in compliance with the License.
14  * You may obtain a copy of the License at
15  *
16  *     http://www.apache.org/licenses/LICENSE-2.0
17  *
18  * Unless required by applicable law or agreed to in writing, software
19  * distributed under the License is distributed on an "AS IS" BASIS,
20  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
21  * See the License for the specific language governing permissions and
22  * limitations under the License.
23  */
24 
25 #ifndef mozilla_pkix_Time_h
26 #define mozilla_pkix_Time_h
27 
28 #include <ctime>
29 #include <limits>
30 #include <stdint.h>
31 
32 #include "pkix/Result.h"
33 
34 namespace mozilla { namespace pkix {
35 
36 // Time with a range from the first second of year 0 (AD) through at least the
37 // last second of year 9999, which is the range of legal times in X.509 and
38 // OCSP. This type has second-level precision. The time zone is always UTC.
39 //
40 // Pass by value, not by reference.
41 class Time final
42 {
43 public:
44   // Construct an uninitialized instance.
45   //
46   // This will fail to compile because there is no default constructor:
47   //    Time x;
48   //
49   // This will succeed, leaving the time uninitialized:
50   //    Time x(Time::uninitialized);
51   enum Uninitialized { uninitialized };
Time(Uninitialized)52   explicit Time(Uninitialized) { }
53 
54   bool operator==(const Time& other) const
55   {
56     return elapsedSecondsAD == other.elapsedSecondsAD;
57   }
58   bool operator>(const Time& other) const
59   {
60     return elapsedSecondsAD > other.elapsedSecondsAD;
61   }
62   bool operator>=(const Time& other) const
63   {
64     return elapsedSecondsAD >= other.elapsedSecondsAD;
65   }
66   bool operator<(const Time& other) const
67   {
68     return elapsedSecondsAD < other.elapsedSecondsAD;
69   }
70   bool operator<=(const Time& other) const
71   {
72     return elapsedSecondsAD <= other.elapsedSecondsAD;
73   }
74 
AddSeconds(uint64_t seconds)75   Result AddSeconds(uint64_t seconds)
76   {
77     if (std::numeric_limits<uint64_t>::max() - elapsedSecondsAD
78           < seconds) {
79       return Result::FATAL_ERROR_INVALID_ARGS; // integer overflow
80     }
81     elapsedSecondsAD += seconds;
82     return Success;
83   }
84 
SubtractSeconds(uint64_t seconds)85   Result SubtractSeconds(uint64_t seconds)
86   {
87     if (seconds > elapsedSecondsAD) {
88       return Result::FATAL_ERROR_INVALID_ARGS; // integer overflow
89     }
90     elapsedSecondsAD -= seconds;
91     return Success;
92   }
93 
94   static const uint64_t ONE_DAY_IN_SECONDS
95     = UINT64_C(24) * UINT64_C(60) * UINT64_C(60);
96 
97 private:
98   // This constructor is hidden to prevent accidents like this:
99   //
100   //    Time foo(time_t t)
101   //    {
102   //      // WRONG! 1970-01-01-00:00:00 == time_t(0), but not Time(0)!
103   //      return Time(t);
104   //    }
Time(uint64_t elapsedSecondsAD)105   explicit Time(uint64_t elapsedSecondsAD)
106     : elapsedSecondsAD(elapsedSecondsAD)
107   {
108   }
109   friend Time TimeFromElapsedSecondsAD(uint64_t);
110   friend class Duration;
111 
112   uint64_t elapsedSecondsAD;
113 };
114 
TimeFromElapsedSecondsAD(uint64_t elapsedSecondsAD)115 inline Time TimeFromElapsedSecondsAD(uint64_t elapsedSecondsAD)
116 {
117   return Time(elapsedSecondsAD);
118 }
119 
120 Time Now();
121 
122 // Note the epoch is the unix epoch (ie 00:00:00 UTC, 1 January 1970)
123 Time TimeFromEpochInSeconds(uint64_t secondsSinceEpoch);
124 
125 class Duration final
126 {
127 public:
Duration(Time timeA,Time timeB)128   Duration(Time timeA, Time timeB)
129     : durationInSeconds(timeA < timeB
130                         ? timeB.elapsedSecondsAD - timeA.elapsedSecondsAD
131                         : timeA.elapsedSecondsAD - timeB.elapsedSecondsAD)
132   {
133   }
134 
Duration(uint64_t durationInSeconds)135   explicit Duration(uint64_t durationInSeconds)
136     : durationInSeconds(durationInSeconds)
137   {
138   }
139 
140   bool operator>(const Duration& other) const
141   {
142     return durationInSeconds > other.durationInSeconds;
143   }
144   bool operator<(const Duration& other) const
145   {
146     return durationInSeconds < other.durationInSeconds;
147   }
148 
149 private:
150   uint64_t durationInSeconds;
151 };
152 
153 } } // namespace mozilla::pkix
154 
155 #endif // mozilla_pkix_Time_h
156