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.

5 files changed, 22 insertions, 19 deletions

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;