Merge pull request #205 from webmaster128/mktime

Add timegm() fallbacks using mktime+TZ or boost

12 files changed, 238 insertions, 11 deletions

diff --git a/src/build-data/os/cygwin.txt b/src/build-data/os/cygwin.txt
index eb5835a6f..be67e2607 100644
--- a/src/build-data/os/cygwin.txt
+++ b/src/build-data/os/cygwin.txt
@@ -13,4 +13,5 @@ doc_dir docs
 <target_features>
 gettimeofday
 getsid
+timegm
 </target_features>
diff --git a/src/build-data/os/darwin.txt b/src/build-data/os/darwin.txt
index f5f2589fb..3a13b34e4 100644
--- a/src/build-data/os/darwin.txt
+++ b/src/build-data/os/darwin.txt
@@ -15,6 +15,7 @@ gmtime_r
 memset_s
 readdir
 getsid
+timegm
 </target_features>
 
 <aliases>
diff --git a/src/build-data/os/freebsd.txt b/src/build-data/os/freebsd.txt
index 346145785..32767cb1f 100644
--- a/src/build-data/os/freebsd.txt
+++ b/src/build-data/os/freebsd.txt
@@ -8,4 +8,5 @@ gmtime_r
 dlopen
 readdir
 getsid
+timegm
 </target_features>
diff --git a/src/build-data/os/linux.txt b/src/build-data/os/linux.txt
index cb78c33ff..48c3bf318 100644
--- a/src/build-data/os/linux.txt
+++ b/src/build-data/os/linux.txt
@@ -8,6 +8,7 @@ gmtime_r
 dlopen
 readdir
 getsid
+timegm
 </target_features>
 
 <aliases>
diff --git a/src/build-data/os/mingw.txt b/src/build-data/os/mingw.txt
index 4f3e7f08b..cc98b11e6 100644
--- a/src/build-data/os/mingw.txt
+++ b/src/build-data/os/mingw.txt
@@ -23,6 +23,7 @@ mingw32
 <target_features>
 cryptgenrandom
 loadlibrary
+mkgmtime
 win32_virtual_lock
 win32_get_systemtime
 </target_features>
diff --git a/src/build-data/os/netbsd.txt b/src/build-data/os/netbsd.txt
index 346145785..32767cb1f 100644
--- a/src/build-data/os/netbsd.txt
+++ b/src/build-data/os/netbsd.txt
@@ -8,4 +8,5 @@ gmtime_r
 dlopen
 readdir
 getsid
+timegm
 </target_features>
diff --git a/src/build-data/os/openbsd.txt b/src/build-data/os/openbsd.txt
index 5df133c8e..510a7accd 100644
--- a/src/build-data/os/openbsd.txt
+++ b/src/build-data/os/openbsd.txt
@@ -7,4 +7,5 @@ posix_mlock
 gmtime_r
 dlopen
 readdir
+timegm
 </target_features>
diff --git a/src/build-data/os/windows.txt b/src/build-data/os/windows.txt
index c34f2e7ab..fd74fe817 100644
--- a/src/build-data/os/windows.txt
+++ b/src/build-data/os/windows.txt
@@ -15,6 +15,7 @@ install_cmd_exec "copy"
 cryptgenrandom
 gmtime_s
 loadlibrary
+mkgmtime
 query_perf_counter
 virtual_lock
 rtlsecurezeromemory
diff --git a/src/lib/utils/calendar.cpp b/src/lib/utils/calendar.cpp
index 0ef8be356..f071a7328 100644
--- a/src/lib/utils/calendar.cpp
+++ b/src/lib/utils/calendar.cpp
@@ -11,6 +11,11 @@
 #include <ctime>
 #include <sstream>
 #include <iomanip>
+#include <mutex>
+
+#if defined(BOTAN_HAS_BOOST_DATETIME)
+#include <boost/date_time/posix_time/posix_time_types.hpp>
+#endif
 
 namespace Botan {
 
@@ -26,7 +31,7 @@ std::tm do_gmtime(std::time_t time_val)
    gmtime_r(&time_val, &tm); // Unix/SUSv2
 #else
    std::tm* tm_p = std::gmtime(&time_val);
-   if (tm_p == 0)
+   if (tm_p == nullptr)
       throw Encoding_Error("time_t_to_tm could not convert");
    tm = *tm_p;
 #endif
@@ -34,11 +39,83 @@ std::tm do_gmtime(std::time_t time_val)
    return tm;
    }
 
+#if !defined(BOTAN_TARGET_OS_HAS_TIMEGM) && !defined(BOTAN_TARGET_OS_HAS_MKGMTIME)
+
+#if defined(BOTAN_HAS_BOOST_DATETIME)
+
+std::time_t boost_timegm(std::tm *tm)
+   {
+   const int sec  = tm->tm_sec;
+   const int min  = tm->tm_min;
+   const int hour = tm->tm_hour;
+   const int day  = tm->tm_mday;
+   const int mon  = tm->tm_mon + 1;
+   const int year = tm->tm_year + 1900;
+
+   std::time_t out;
+
+      {
+      using namespace boost::posix_time;
+      using namespace boost::gregorian;
+      const auto epoch = ptime(date(1970, 01, 01));
+      const auto time = ptime(date(year, mon, day), 
+                              hours(hour) + minutes(min) + seconds(sec));
+      const time_duration diff(time - epoch);
+      out = diff.ticks() / diff.ticks_per_second();
+      }
+
+   return out;
+   }
+
+#else
+
+#pragma message "Caution! A fallback version of timegm() is used which is not thread-safe"
+
+std::mutex ENV_TZ;
+
+std::time_t fallback_timegm(std::tm *tm)
+   {
+   std::time_t out;
+   std::string tz_backup;
+
+   ENV_TZ.lock();
+
+   // Store current value of env variable TZ
+   const char* tz_env_pointer = ::getenv("TZ");
+   if (tz_env_pointer != nullptr)
+      tz_backup = std::string(tz_env_pointer);
+
+   // Clear value of TZ
+   ::setenv("TZ", "", 1);
+   ::tzset();
+   
+   out = ::mktime(tm);
+
+   // Restore TZ
+   if (!tz_backup.empty())
+      {
+      // setenv makes a copy of the second argument
+      ::setenv("TZ", tz_backup.data(), 1);
+      }
+   else
+      {
+      ::unsetenv("TZ");
+      }
+   ::tzset();
+
+   ENV_TZ.unlock();
+
+   return out;
+}
+#endif // BOTAN_HAS_BOOST_DATETIME
+
+#endif
+
 }
 
 std::chrono::system_clock::time_point calendar_point::to_std_timepoint()
    {
-   if (year < 1900)
+   if (year < 1970)
       throw Invalid_Argument("calendar_point::to_std_timepoint() does not support years before 1990.");
 
    // 32 bit time_t ends at January 19, 2038
@@ -48,7 +125,9 @@ std::chrono::system_clock::time_point calendar_point::to_std_timepoint()
    if (year > 2037)
       throw Invalid_Argument("calendar_point::to_std_timepoint() does not support years after 2037.");
 
+   // std::tm: struct without any timezone information
    std::tm tm;
+   tm.tm_isdst = -1; // i.e. no DST information available
    tm.tm_sec   = seconds;
    tm.tm_min   = minutes;
    tm.tm_hour  = hour;
@@ -56,12 +135,20 @@ std::chrono::system_clock::time_point calendar_point::to_std_timepoint()
    tm.tm_mon   = month - 1;
    tm.tm_year  = year - 1900;
 
-   // Convert std::tm to std::time_t
+   // Define a function alias `botan_timegm`
+   #if defined(BOTAN_TARGET_OS_HAS_TIMEGM)
+   std::time_t (&botan_timegm)(std::tm *tm) = timegm;
+   #elif defined(BOTAN_TARGET_OS_HAS_MKGMTIME)
    // http://stackoverflow.com/questions/16647819/timegm-cross-platform
-   #if defined(BOTAN_TARGET_OS_IS_WINDOWS)
-   #define timegm _mkgmtime
+   std::time_t (&botan_timegm)(std::tm *tm) = _mkgmtime;
+   #elif defined(BOTAN_HAS_BOOST_DATETIME)
+   std::time_t (&botan_timegm)(std::tm *tm) = boost_timegm;
+   #else
+   std::time_t (&botan_timegm)(std::tm *tm) = fallback_timegm;
    #endif
-   std::time_t tt = timegm(&tm);
+
+   // Convert std::tm to std::time_t
+   std::time_t tt = botan_timegm(&tm);
    if (tt == -1)
       throw Invalid_Argument("calendar_point couldn't be converted: " + to_string());
 
diff --git a/src/lib/vendor/boost/info.txt b/src/lib/vendor/boost/info.txt
index c335dcd74..8748c0bf1 100644
--- a/src/lib/vendor/boost/info.txt
+++ b/src/lib/vendor/boost/info.txt
@@ -1,5 +1,6 @@
 define BOOST_FILESYSTEM 20131228
 define BOOST_ASIO 20131228
+define BOOST_DATETIME 20150720
 
 load_on vendor
 
diff --git a/src/scripts/update_docs.py b/src/scripts/update_docs.py
new file mode 100755
index 000000000..03b9dd67b
--- /dev/null
+++ b/src/scripts/update_docs.py
@@ -0,0 +1,100 @@
+#!/usr/bin/env python3
+
+"""
+A script to automatically write docs to /docs. Currently it generates
+os.rst, a feature table of OS features.
+
+Requires Python 3.
+
+(C) 2015 Simon Warta (Kullo GmbH)
+
+Botan is released under the Simplified BSD License (see license.txt)
+"""
+
+# global
+import argparse
+import glob
+import os
+import sys
+
+# Assume this script is in botan/src/scripts
+botan_root = os.path.join(os.path.dirname(sys.argv[0]), "..", "..")
+
+# locale
+sys.path.append(botan_root)
+from configure import OsInfo
+
+parser = argparse.ArgumentParser(description="")
+parser.add_argument('--verbose', dest='verbose', action='store_const',
+                    const=True, default=False,
+                    help='Verbose output (default: false)')
+args = parser.parse_args()
+
+def update_os():
+    PAGE_TITLE="Botan OS information"
+    TABLE_TITLE="OS Features"
+
+    files = []
+    files += glob.glob(botan_root + '/src/build-data/os/*.txt')
+    files.sort()
+
+    if len(files) == 0:
+        print("No info.txt files found.")
+        sys.exit(1)
+
+    f1 = open(os.path.join(botan_root, 'doc', 'os.rst'), 'w+')    
+
+    all_features = set()
+    oss = {}
+
+    for filename in files:
+        o = OsInfo(filename)
+        oss[o.basename] = o
+        all_features |= set(o.target_features)
+        if args.verbose:
+            print(o.basename)
+            print(o.target_features)
+
+    featurelist = list(all_features)
+    featurelist.sort()
+    oslist = list(oss.keys())
+    oslist.sort()
+
+    if args.verbose:
+        print(featurelist)
+
+    print(PAGE_TITLE, file=f1)
+    print("========================================", file=f1)
+    print("", file=f1)
+
+    print(TABLE_TITLE, file=f1)
+    print("^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^", file=f1)
+    print("", file=f1)
+
+    print("A summary of OS features as defined in ``src/build-data/os``.", file=f1)
+    print("", file=f1)
+
+    print("::", file=f1)
+    print("", file=f1)
+    for o in oslist:
+        print("  %s: %s" % (o[0:1], o), file=f1)
+    print("", file=f1)
+
+    print('.. csv-table::', file=f1)
+    print('   :header: "Feature", "' + '", "'.join([o[0:1] for o in oslist]) + '"', file=f1)
+    print('', file=f1)
+
+    for f in featurelist:
+        line = '   "' + f + '"'
+        for o in oslist:
+            line += ', "'
+            line += 'X' if f in oss[o].target_features else ' '
+            line += '"'
+        print(line, file=f1)
+    print("", file=f1)
+    print(".. note::", file=f1)
+    print("   This file is auto generated by ``src/scripts/%s``. Dont modify it manually."
+                    % os.path.basename(sys.argv[0]), file=f1)
+
+if __name__ == '__main__':
+    update_os()
diff --git a/src/tests/catchy/test_utils.cpp b/src/tests/catchy/test_utils.cpp
index ad4191e3c..702d82f9c 100644
--- a/src/tests/catchy/test_utils.cpp
+++ b/src/tests/catchy/test_utils.cpp
@@ -100,6 +100,7 @@ TEST_CASE("calendar_point constructor works", "[utils]")
 
 TEST_CASE("calendar_point to stl timepoint and back", "[utils]")
    {
+   SECTION("default test")
       {
       auto in = calendar_point(1988, 04, 23, 14, 37, 28);
       auto out = calendar_value(in.to_std_timepoint());
@@ -111,7 +112,20 @@ TEST_CASE("calendar_point to stl timepoint and back", "[utils]")
       CHECK(( out.seconds == 28 ));
       }
 
-      SECTION("latest possible time point")
+   // _mkgmtime on Windows does not work for dates before 1970
+   SECTION("first possible time point")
+      {
+      auto in = calendar_point(1970, 01, 01, 00, 00, 00);
+      auto out = calendar_value(in.to_std_timepoint());
+      CHECK(( out.year    == 1970 ));
+      CHECK(( out.month   == 01 ));
+      CHECK(( out.day     == 01 ));
+      CHECK(( out.hour    == 00 ));
+      CHECK(( out.minutes == 00 ));
+      CHECK(( out.seconds == 00 ));
+      }
+
+   SECTION("latest possible time point")
       {
       auto in = calendar_point(2037, 12, 31, 23, 59, 59);
       auto out = calendar_value(in.to_std_timepoint());
@@ -123,13 +137,30 @@ TEST_CASE("calendar_point to stl timepoint and back", "[utils]")
       CHECK(( out.seconds == 59 ));
       }
 
-      SECTION("year too early")
+   SECTION("year too early")
       {
-      auto in = calendar_point(1800, 01, 01, 0, 0, 0);
-      CHECK_THROWS( in.to_std_timepoint() );
+         {
+         auto in = calendar_point(1800, 01, 01, 0, 0, 0);
+         CHECK_THROWS( in.to_std_timepoint() );
+         }
+
+         {
+         auto in = calendar_point(1899, 12, 31, 23, 59, 59);
+         CHECK_THROWS( in.to_std_timepoint() );
+         }
+
+         {
+         auto in = calendar_point(1969, 12, 31, 23, 59, 58); // time_t = -2
+         CHECK_THROWS( in.to_std_timepoint() );
+         }
+
+         {
+         auto in = calendar_point(1969, 12, 31, 23, 59, 59); // time_t = -1
+         CHECK_THROWS( in.to_std_timepoint() );
+         }
       }
 
-      SECTION("year too late")
+   SECTION("year too late")
       {
       auto in = calendar_point(2038, 01, 01, 0, 0, 0);
       CHECK_THROWS( in.to_std_timepoint() );