Remove system_time(), replace entirely with std::chrono.

Only remaining use of time.h/ctime is to convert from a time point to
a calendar value, which still requires C's gmtime. Hide it entirely in
time.cpp and return a calendar_point struct instead of a std::tm.

13 files changed, 116 insertions, 136 deletions

diff --git a/checks/cvc_tests.cpp b/checks/cvc_tests.cpp
index 4b2ffa9a6..7904a2700 100644
--- a/checks/cvc_tests.cpp
+++ b/checks/cvc_tests.cpp
@@ -350,8 +350,7 @@ void test_eac_time(RandomNumberGenerator&)
    {
    std::cout << "." << std::flush;
 
-   const u64bit current_time = system_time();
-   EAC_Time time(current_time);
+   EAC_Time time(std::chrono::system_clock::now());
    //     std::cout << "time as std::string = " << time.as_string() << std::endl;
    EAC_Time sooner("", ASN1_Tag(99));
    //X509_Time sooner("", ASN1_Tag(99));
diff --git a/src/asn1/asn1_obj.h b/src/asn1/asn1_obj.h
index ea21c475f..a640f712b 100644
--- a/src/asn1/asn1_obj.h
+++ b/src/asn1/asn1_obj.h
@@ -14,6 +14,7 @@
 #include <botan/alg_id.h>
 #include <vector>
 #include <map>
+#include <chrono>
 
 namespace Botan {
 
@@ -52,7 +53,7 @@ class BOTAN_DLL X509_Time : public ASN1_Object
       void set_to(const std::string&);
       void set_to(const std::string&, ASN1_Tag);
 
-      X509_Time(u64bit);
+      X509_Time(const std::chrono::system_clock::time_point& time);
       X509_Time(const std::string& = "");
       X509_Time(const std::string&, ASN1_Tag);
    private:
diff --git a/src/asn1/asn1_tm.cpp b/src/asn1/asn1_tm.cpp
index 9df10f4a3..6e56bb8d1 100644
--- a/src/asn1/asn1_tm.cpp
+++ b/src/asn1/asn1_tm.cpp
@@ -23,18 +23,18 @@ X509_Time::X509_Time(const std::string& time_str)
    }
 
 /*
-* Create an X509_Time
+* Create a X509_Time from a time point
 */
-X509_Time::X509_Time(u64bit timer)
+X509_Time::X509_Time(const std::chrono::system_clock::time_point& time)
    {
-   std::tm time_info = time_t_to_tm(timer);
-
-   year   = time_info.tm_year + 1900;
-   month  = time_info.tm_mon + 1;
-   day    = time_info.tm_mday;
-   hour   = time_info.tm_hour;
-   minute = time_info.tm_min;
-   second = time_info.tm_sec;
+   calendar_point cal = calendar_value(time);
+
+   year   = cal.year;
+   month  = cal.month;
+   day    = cal.day;
+   hour   = cal.hour;
+   minute = cal.minutes;
+   second = cal.seconds;
 
    if(year >= 2050)
       tag = GENERALIZED_TIME;
diff --git a/src/cert/cvc/asn1_eac_tm.cpp b/src/cert/cvc/asn1_eac_tm.cpp
index b0238ac4d..827710084 100644
--- a/src/cert/cvc/asn1_eac_tm.cpp
+++ b/src/cert/cvc/asn1_eac_tm.cpp
@@ -50,24 +50,24 @@ u32bit dec_two_digit(byte b1, byte b2)
 /*
 * Create an EAC_Time
 */
-EAC_Time::EAC_Time(u64bit timer, ASN1_Tag t)
-   :tag(t)
+EAC_Time::EAC_Time(const std::chrono::system_clock::time_point& time,
+                   ASN1_Tag t) : tag(t)
    {
-   std::tm time_info = time_t_to_tm(timer);
+   calendar_point cal = calendar_value(time);
 
-   year   = time_info.tm_year + 1900;
-   month  = time_info.tm_mon + 1;
-   day    = time_info.tm_mday;
+   year   = cal.year;
+   month  = cal.month;
+   day    = cal.day;
    }
 
 /*
 * Create an EAC_Time
 */
-EAC_Time::EAC_Time(const std::string& t_spec, ASN1_Tag t)
-   :tag(t)
+EAC_Time::EAC_Time(const std::string& t_spec, ASN1_Tag t) : tag(t)
    {
    set_to(t_spec);
    }
+
 /*
 * Create an EAC_Time
 */
@@ -280,19 +280,6 @@ void EAC_Time::decode_from(BER_Decoder& source)
 
    }
 
-u32bit EAC_Time::get_year() const
-   {
-   return year;
-   }
-u32bit EAC_Time::get_month() const
-   {
-   return month;
-   }
-u32bit EAC_Time::get_day() const
-   {
-   return day;
-   }
-
 /*
 * make the value an octet string for encoding
 */
@@ -305,28 +292,4 @@ SecureVector<byte> EAC_Time::encoded_eac_time() const
    return result;
    }
 
-ASN1_Ced::ASN1_Ced(std::string const& str)
-   : EAC_Time(str, ASN1_Tag(37))
-   {}
-
-ASN1_Ced::ASN1_Ced(u64bit val)
-   : EAC_Time(val, ASN1_Tag(37))
-   {}
-
-ASN1_Ced::ASN1_Ced(EAC_Time const& other)
-   : EAC_Time(other.get_year(), other.get_month(), other.get_day(), ASN1_Tag(37))
-   {}
-
-ASN1_Cex::ASN1_Cex(std::string const& str)
-   : EAC_Time(str, ASN1_Tag(36))
-   {}
-
-ASN1_Cex::ASN1_Cex(u64bit val)
-   : EAC_Time(val, ASN1_Tag(36))
-   {}
-
-ASN1_Cex::ASN1_Cex(EAC_Time const& other)
-   : EAC_Time(other.get_year(), other.get_month(), other.get_day(), ASN1_Tag(36))
-   {}
-
 }
diff --git a/src/cert/cvc/cvc_self.cpp b/src/cert/cvc/cvc_self.cpp
index 98d90d0af..3b764644f 100644
--- a/src/cert/cvc/cvc_self.cpp
+++ b/src/cert/cvc/cvc_self.cpp
@@ -181,9 +181,8 @@ EAC1_1_CVC create_cvca(Private_Key const& key,
       }
    EAC1_1_CVC_Options opts;
    opts.car = car;
-   const u64bit current_time = system_time();
 
-   opts.ced = ASN1_Ced(current_time);
+   opts.ced = ASN1_Ced(std::chrono::system_clock::now());
    opts.cex = ASN1_Cex(opts.ced);
    opts.cex.add_months(cvca_validity_months);
    opts.holder_auth_templ = (CVCA | (iris * IRIS) | (fingerpr * FINGERPRINT));
@@ -198,12 +197,12 @@ EAC1_1_CVC link_cvca(EAC1_1_CVC const& signer,
                      EAC1_1_CVC const& signee,
                      RandomNumberGenerator& rng)
    {
-   ECDSA_PrivateKey const* priv_key = dynamic_cast<ECDSA_PrivateKey const*>(&key);
+   const ECDSA_PrivateKey* priv_key = dynamic_cast<ECDSA_PrivateKey const*>(&key);
+
    if (priv_key == 0)
-      {
-      throw Invalid_Argument("CVC_EAC::create_self_signed_cert(): unsupported key type");
-      }
-   ASN1_Ced ced(system_time());
+      throw Invalid_Argument("link_cvca(): unsupported key type");
+
+   ASN1_Ced ced(std::chrono::system_clock::now());
    ASN1_Cex cex(signee.get_cex());
    if (*static_cast<EAC_Time*>(&ced) > *static_cast<EAC_Time*>(&cex))
       {
@@ -278,8 +277,9 @@ EAC1_1_CVC sign_request(EAC1_1_CVC const& signer_cert,
 #endif
 
    AlgorithmIdentifier sig_algo(signer_cert.signature_algorithm());
-   const u64bit current_time = system_time();
-   ASN1_Ced ced(current_time);
+
+   ASN1_Ced ced(std::chrono::system_clock::now());
+
    u32bit chat_val;
    u32bit chat_low = signer_cert.get_chat_value() & 0x3; // take the chat rights from signer
    ASN1_Cex cex(ced);
diff --git a/src/cert/cvc/eac_asn_obj.h b/src/cert/cvc/eac_asn_obj.h
index 3e70f6b74..a6685a8ed 100644
--- a/src/cert/cvc/eac_asn_obj.h
+++ b/src/cert/cvc/eac_asn_obj.h
@@ -1,7 +1,7 @@
 /*
 * EAC ASN.1 Objects
 * (C) 2007-2008 FlexSecure GmbH
-*     2008 Jack Lloyd
+*     2008-2009 Jack Lloyd
 *
 * Distributed under the terms of the Botan license
 */
@@ -12,6 +12,7 @@
 #include <botan/asn1_obj.h>
 #include <vector>
 #include <map>
+#include <chrono>
 
 namespace Botan {
 
@@ -58,7 +59,6 @@ class BOTAN_DLL EAC_Time : public ASN1_Object
       * e.g. "2007 08 01"
       */
       void set_to(const std::string& str);
-      //void set_to(const std::string&, ASN1_Tag);
 
       /**
       * Add the specified number of years to this.
@@ -76,24 +76,28 @@ class BOTAN_DLL EAC_Time : public ASN1_Object
       * Get the year value of this objects.
       * @return the year value
       */
-      u32bit get_year() const;
+      u32bit get_year() const { return year; }
 
       /**
       * Get the month value of this objects.
       * @return the month value
       */
-      u32bit get_month() const;
+      u32bit get_month() const { return month; }
 
       /**
       * Get the day value of this objects.
       * @return the day value
       */
-      u32bit get_day() const;
+      u32bit get_day() const { return day; }
 
-      EAC_Time(u64bit, ASN1_Tag t = ASN1_Tag(0));
-      //EAC_Time(const std::string& = "");
-      EAC_Time(const std::string&, ASN1_Tag = ASN1_Tag(0));
-      EAC_Time(u32bit year, u32bit month, u32bit day, ASN1_Tag = ASN1_Tag(0));
+      EAC_Time(const std::chrono::system_clock::time_point& time,
+               ASN1_Tag tag = ASN1_Tag(0));
+
+      EAC_Time(const std::string& yyyy_mm_dd,
+               ASN1_Tag tag = ASN1_Tag(0));
+
+      EAC_Time(u32bit year, u32bit month, u32bit day,
+               ASN1_Tag tag = ASN1_Tag(0));
 
       virtual ~EAC_Time() {}
    private:
@@ -115,25 +119,25 @@ class BOTAN_DLL ASN1_Ced : public EAC_Time
       * @param str a string in the format "yyyy mm dd",
       * e.g. "2007 08 01"
       */
-      ASN1_Ced(std::string const& str = "");
+      ASN1_Ced(std::string const& str = "") :
+         EAC_Time(str, ASN1_Tag(37)) {}
 
       /**
-      * Construct a CED from a timer value.
-      * @param time the number of seconds elapsed midnight, 1st
-      * January 1970 GMT (or 7pm, 31st December 1969 EST) up to the
-      * desired date
+      * Construct a CED from a time point
       */
-      ASN1_Ced(u64bit time);
+      ASN1_Ced(const std::chrono::system_clock::time_point& time) :
+         EAC_Time(time, ASN1_Tag(37)) {}
 
       /**
       * Copy constructor (for general EAC_Time objects).
       * @param other the object to copy from
       */
-      ASN1_Ced(EAC_Time const& other);
-      //ASN1_Ced(ASN1_Cex const& cex);
+      ASN1_Ced(EAC_Time const& other) :
+         EAC_Time(other.get_year(), other.get_month(), other.get_day(),
+                  ASN1_Tag(37))
+         {}
    };
 
-
 /**
 * This class represents CVC CEXs. Only limited sanity checks of
 * the inputted date value are performed.
@@ -142,27 +146,20 @@ class BOTAN_DLL ASN1_Cex : public EAC_Time
    {
    public:
       /**
-      * Construct a CED from a string value.
+      * Construct a CEX from a string value.
       * @param str a string in the format "yyyy mm dd",
       * e.g. "2007 08 01"
       */
-      ASN1_Cex(std::string const& str="");
+      ASN1_Cex(std::string const& str = "") :
+         EAC_Time(str, ASN1_Tag(36)) {}
 
-      /**
-      * Construct a CED from a timer value.
-      * @param time the number of seconds elapsed
-      *  midnight, 1st
-      * January 1970 GMT (or 7pm, 31st December 1969 EST)
-      * up to the desired date
-      */
-      ASN1_Cex(u64bit time);
+      ASN1_Cex(const std::chrono::system_clock::time_point& time) :
+         EAC_Time(time, ASN1_Tag(36)) {}
 
-      /**
-      * Copy constructor (for general EAC_Time objects).
-      * @param other the object to copy from
-      */
-      ASN1_Cex(EAC_Time const& other);
-      //ASN1_Cex(ASN1_Ced const& ced);
+      ASN1_Cex(EAC_Time const& other) :
+         EAC_Time(other.get_year(), other.get_month(), other.get_day(),
+                  ASN1_Tag(36))
+         {}
    };
 
 /**
diff --git a/src/cert/x509/crl_ent.cpp b/src/cert/x509/crl_ent.cpp
index 42a742ebb..e7ce1a57a 100644
--- a/src/cert/x509/crl_ent.cpp
+++ b/src/cert/x509/crl_ent.cpp
@@ -11,7 +11,6 @@
 #include <botan/ber_dec.h>
 #include <botan/bigint.h>
 #include <botan/oids.h>
-#include <botan/time.h>
 
 namespace Botan {
 
@@ -31,7 +30,7 @@ CRL_Entry::CRL_Entry(const X509_Certificate& cert, CRL_Code why) :
    throw_on_unknown_critical(false)
    {
    serial = cert.serial_number();
-   time = X509_Time(system_time());
+   time = X509_Time(std::chrono::system_clock::now());
    reason = why;
    }
 
diff --git a/src/cert/x509/x509_ca.cpp b/src/cert/x509/x509_ca.cpp
index 80e808177..59a5bbaf8 100644
--- a/src/cert/x509/x509_ca.cpp
+++ b/src/cert/x509/x509_ca.cpp
@@ -14,7 +14,6 @@
 #include <botan/lookup.h>
 #include <botan/look_pk.h>
 #include <botan/oids.h>
-#include <botan/time.h>
 #include <memory>
 #include <set>
 
@@ -197,7 +196,8 @@ X509_CRL X509_CA::make_crl(const std::vector<CRL_Entry>& revoked,
       next_update = timespec_to_u32bit("7d");
 
    // Totally stupid: ties encoding logic to the return of std::time!!
-   const u64bit current_time = system_time();
+   auto current_time = std::chrono::system_clock::now();
+   auto expire_time = current_time + std::chrono::seconds(next_update);
 
    Extensions extensions;
    extensions.add(
@@ -210,7 +210,7 @@ X509_CRL X509_CA::make_crl(const std::vector<CRL_Entry>& revoked,
             .encode(ca_sig_algo)
             .encode(cert.issuer_dn())
             .encode(X509_Time(current_time))
-            .encode(X509_Time(current_time + next_update))
+            .encode(X509_Time(expire_time))
             .encode_if(revoked.size() > 0,
                  DER_Encoder()
                     .start_cons(SEQUENCE)
diff --git a/src/cert/x509/x509opt.cpp b/src/cert/x509/x509opt.cpp
index c6421d9ca..a2547e30a 100644
--- a/src/cert/x509/x509opt.cpp
+++ b/src/cert/x509/x509opt.cpp
@@ -78,16 +78,16 @@ void X509_Cert_Options::sanity_check() const
 * Initialize the certificate options
 */
 X509_Cert_Options::X509_Cert_Options(const std::string& initial_opts,
-                                     u32bit expiration_time_in_seconds)
+                                     u32bit expiration_time)
    {
    is_CA = false;
    path_limit = 0;
    constraints = NO_CONSTRAINTS;
 
-   const u32bit now = system_time();
+   auto now = std::chrono::system_clock::now();
 
    start = X509_Time(now);
-   end = X509_Time(now + expiration_time_in_seconds);
+   end = X509_Time(now + std::chrono::seconds(expiration_time));
 
    if(initial_opts == "")
       return;
diff --git a/src/cert/x509/x509stor.cpp b/src/cert/x509/x509stor.cpp
index 323890f2d..336d155d3 100644
--- a/src/cert/x509/x509stor.cpp
+++ b/src/cert/x509/x509stor.cpp
@@ -22,13 +22,14 @@ namespace {
 * Do a validity check
 */
 s32bit validity_check(const X509_Time& start, const X509_Time& end,
-                      u64bit current_time, u32bit slack)
+                      const std::chrono::system_clock::time_point& now,
+                      u32bit slack)
    {
    const s32bit NOT_YET_VALID = -1, VALID_TIME = 0, EXPIRED = 1;
 
-   if(start.cmp(current_time + slack) > 0)
+   if(start.cmp(now + std::chrono::seconds(slack)) > 0)
       return NOT_YET_VALID;
-   if(end.cmp(current_time - slack) < 0)
+   if(end.cmp(now - std::chrono::seconds(slack)) < 0)
       return EXPIRED;
    return VALID_TIME;
    }
@@ -212,10 +213,11 @@ X509_Code X509_Store::validate_cert(const X509_Certificate& cert,
    if(chaining_result != VERIFIED)
       return chaining_result;
 
-   const u64bit current_time = system_time();
+   auto current_time = std::chrono::system_clock::now();
 
    s32bit time_check = validity_check(cert.start_time(), cert.end_time(),
                                       current_time, time_slack);
+
    if(time_check < 0)      return CERT_NOT_YET_VALID;
    else if(time_check > 0) return CERT_HAS_EXPIRED;
 
@@ -563,8 +565,10 @@ void X509_Store::add_trusted_certs(DataSource& source)
 */
 X509_Code X509_Store::add_crl(const X509_CRL& crl)
    {
+   auto current_time = std::chrono::system_clock::now();
+
    s32bit time_check = validity_check(crl.this_update(), crl.next_update(),
-                                      system_time(), time_slack);
+                                      current_time, time_slack);
 
    if(time_check < 0)      return CRL_NOT_YET_VALID;
    else if(time_check > 0) return CRL_HAS_EXPIRED;
@@ -641,8 +645,8 @@ X509_Store::Cert_Info::Cert_Info(const X509_Certificate& c,
                                  bool t) : cert(c), trusted(t)
    {
    checked = false;
+   last_checked = std::chrono::system_clock::time_point::min();
    result = UNKNOWN_X509_ERROR;
-   last_checked = 0;
    }
 
 /*
@@ -660,9 +664,9 @@ X509_Code X509_Store::Cert_Info::verify_result() const
 */
 void X509_Store::Cert_Info::set_result(X509_Code code) const
    {
-   result = code;
-   last_checked = system_time();
    checked = true;
+   last_checked = std::chrono::system_clock::now();
+   result = code;
    }
 
 /*
@@ -683,9 +687,9 @@ bool X509_Store::Cert_Info::is_verified(u32bit timeout) const
    if(result != VERIFIED && result != CERT_NOT_YET_VALID)
       return true;
 
-   const u64bit current_time = system_time();
+   auto now = std::chrono::system_clock::now();
 
-   if(current_time > last_checked + timeout)
+   if(now > last_checked + std::chrono::seconds(timeout))
       checked = false;
 
    return checked;
diff --git a/src/cert/x509/x509stor.h b/src/cert/x509/x509stor.h
index 958b6da0f..e55e36e7e 100644
--- a/src/cert/x509/x509stor.h
+++ b/src/cert/x509/x509stor.h
@@ -116,7 +116,7 @@ class BOTAN_DLL X509_Store
          private:
             mutable bool checked;
             mutable X509_Code result;
-            mutable u64bit last_checked;
+            mutable std::chrono::system_clock::time_point last_checked;
          };
 
       u32bit find_cert(const X509_DN&, const MemoryRegion<byte>&) const;
diff --git a/src/utils/time.cpp b/src/utils/time.cpp
index 856b1c7be..1c64c820e 100644
--- a/src/utils/time.cpp
+++ b/src/utils/time.cpp
@@ -45,25 +45,30 @@ u64bit combine_timers(u32bit seconds, u32bit parts, u32bit parts_hz)
 
 }
 
-/**
-* Get the system clock
-*/
-u64bit system_time()
-   {
-   return static_cast<u64bit>(std::time(0));
-   }
-
 /*
 * Convert a time_t to a struct tm
 */
-std::tm time_t_to_tm(u64bit timer)
+calendar_point calendar_value(
+   const std::chrono::system_clock::time_point& time_point)
    {
-   std::time_t time_val = static_cast<std::time_t>(timer);
+   time_t time_val = std::chrono::system_clock::to_time_t(time_point);
+
+   // Race condition: std::gmtime is not assured thread safe,
+   // and C++ does not include gmtime_r. Use a mutex here?
 
    std::tm* tm_p = std::gmtime(&time_val);
    if (tm_p == 0)
       throw Encoding_Error("time_t_to_tm could not convert");
-   return (*tm_p);
+
+   std::tm tm = *tm_p;
+   // Race is over here
+
+   return calendar_point(tm.tm_year + 1900,
+                         tm.tm_mon + 1,
+                         tm.tm_mday,
+                         tm.tm_hour,
+                         tm.tm_min,
+                         tm.tm_sec);
    }
 
 u64bit get_nanoseconds_clock()
diff --git a/src/utils/time.h b/src/utils/time.h
index c7f459096..28b777efe 100644
--- a/src/utils/time.h
+++ b/src/utils/time.h
@@ -9,16 +9,28 @@
 #define BOTAN_TIME_H__
 
 #include <botan/types.h>
-#include <ctime>
+#include <chrono>
 
 namespace Botan {
 
 /*
-* Time Access/Conversion Functions
+* Time Conversion Functions
 */
-BOTAN_DLL u64bit system_time();
-
-BOTAN_DLL std::tm time_t_to_tm(u64bit);
+struct BOTAN_DLL calendar_point
+   {
+   u32bit year;
+   byte month;
+   byte day;
+   byte hour;
+   byte minutes;
+   byte seconds;
+
+   calendar_point(u32bit y, byte mon, byte d, byte h, byte min, byte sec) :
+      year(y), month(mon), day(d), hour(h), minutes(min), seconds(sec) {}
+   };
+
+BOTAN_DLL calendar_point calendar_value(
+   const std::chrono::system_clock::time_point& time_point);
 
 /**
 @return nanoseconds resolution timestamp, unknown epoch