1 files changed, 28 insertions, 24 deletions

diff --git a/src/asn1/asn1_tm.cpp b/src/asn1/asn1_tm.cpp
index a059e0528..6e6868972 100644
--- a/src/asn1/asn1_tm.cpp
+++ b/src/asn1/asn1_tm.cpp
@@ -23,11 +23,11 @@ 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)
    {
-   calendar_point cal = calendar_value(timer);
+   calendar_point cal = calendar_value(time);
 
    year   = cal.year;
    month  = cal.month;
@@ -98,7 +98,7 @@ void X509_Time::set_to(const std::string& time_str)
 void X509_Time::set_to(const std::string& t_spec, ASN1_Tag spec_tag)
    {
    if(spec_tag != GENERALIZED_TIME && spec_tag != UTC_TIME)
-      throw Invalid_Argument("X509_Time: Invalid tag " + to_string(spec_tag));
+      throw Invalid_Argument("X509_Time: Invalid tag " + std::to_string(spec_tag));
 
    if(spec_tag == GENERALIZED_TIME && t_spec.size() != 13 && t_spec.size() != 15)
       throw Invalid_Argument("Invalid GeneralizedTime: " + t_spec);
@@ -182,24 +182,30 @@ std::string X509_Time::as_string() const
    if(time_is_set() == false)
       throw Invalid_State("X509_Time::as_string: No time set");
 
-   std::string asn1rep;
-   if(tag == GENERALIZED_TIME)
-      asn1rep = to_string(year, 4);
-   else if(tag == UTC_TIME)
+   u32bit full_year = year;
+
+   if(tag == UTC_TIME)
       {
       if(year < 1950 || year >= 2050)
          throw Encoding_Error("X509_Time: The time " + readable_string() +
                               " cannot be encoded as a UTCTime");
-      u32bit asn1year = (year >= 2000) ? (year - 2000) : (year - 1900);
-      asn1rep = to_string(asn1year, 2);
+
+      full_year = (year >= 2000) ? (year - 2000) : (year - 1900);
       }
-   else
-      throw Invalid_Argument("X509_Time: Invalid tag " + to_string(tag));
 
-   asn1rep += to_string(month, 2) + to_string(day, 2);
-   asn1rep += to_string(hour, 2) + to_string(minute, 2) + to_string(second, 2);
-   asn1rep += "Z";
-   return asn1rep;
+   std::string repr = std::to_string(full_year*10000000000 +
+                                     month*100000000 +
+                                     day*1000000 +
+                                     hour*10000 +
+                                     minute*100 +
+                                     second) + "Z";
+
+   u32bit desired_size = (tag == UTC_TIME) ? 13 : 15;
+
+   while(repr.size() < desired_size)
+      repr = "0" + repr;
+
+   return repr;
    }
 
 /*
@@ -218,14 +224,12 @@ std::string X509_Time::readable_string() const
    if(time_is_set() == false)
       throw Invalid_State("X509_Time::readable_string: No time set");
 
-   std::string readable;
-   readable += to_string(year,   4) + "/";
-   readable += to_string(month    ) + "/";
-   readable += to_string(day      ) + " ";
-   readable += to_string(hour     ) + ":";
-   readable += to_string(minute, 2) + ":";
-   readable += to_string(second, 2) + " UTC";
-   return readable;
+   std::string output(24, 0);
+
+   std::sprintf(&output[0], "%04d/%02d/%02d %02d:%02d:%02d UTC",
+                year, month, day, hour, minute, second);
+
+   return output;
    }
 
 /*