/*

* X.509 Time Types

* (C) 1999-2007 Jack Lloyd

*

* Botan is released under the Simplified BSD License (see license.txt)

*/

#include <botan/asn1_obj.h>

#include <botan/der_enc.h>

#include <botan/ber_dec.h>

#include <botan/exceptn.h>

#include <botan/internal/parsing.h>

#include <botan/internal/calendar.h>

#include <sstream>

#include <iomanip>

namespace Botan {

ASN1_Time::ASN1_Time(const std::chrono::system_clock::time_point& time)

   {

   calendar_point cal(time);

   m_year   = cal.year();

   m_month  = cal.month();

   m_day    = cal.day();

   m_hour   = cal.hour();

   m_minute = cal.minutes();

   m_second = cal.seconds();

   m_tag = (m_year >= 2050) ? ASN1_Type::GeneralizedTime : ASN1_Type::UtcTime;

   }

ASN1_Time::ASN1_Time(const std::string& t_spec, ASN1_Type tag)

   {

   set_to(t_spec, tag);

   }

ASN1_Time::ASN1_Time(const std::string& t_spec)

   {

   if(t_spec.size() == 13)

      set_to(t_spec, ASN1_Type::UtcTime);

   else if(t_spec.size() == 15)

      set_to(t_spec, ASN1_Type::GeneralizedTime);

   else

      throw Invalid_Argument("Time string could not be parsed as GeneralizedTime or UTCTime.");

   }

void ASN1_Time::encode_into(DER_Encoder& der) const

   {

   BOTAN_ARG_CHECK(m_tag == ASN1_Type::UtcTime || m_tag == ASN1_Type::GeneralizedTime,

                   "ASN1_Time: Bad encoding tag");

   der.add_object(m_tag, ASN1_Class::Universal, to_string());

   }

void ASN1_Time::decode_from(BER_Decoder& source)

   {

   BER_Object ber_time = source.get_next_object();

   set_to(ASN1::to_string(ber_time), ber_time.type());

   }

std::string ASN1_Time::to_string() const

   {

   if(time_is_set() == false)

      throw Invalid_State("ASN1_Time::to_string: No time set");

   uint32_t full_year = m_year;

   if(m_tag == ASN1_Type::UtcTime)

      {

      if(m_year < 1950 || m_year >= 2050)

         throw Encoding_Error("ASN1_Time: The time " + readable_string() +

                              " cannot be encoded as a UTCTime");

      full_year = (m_year >= 2000) ? (m_year - 2000) : (m_year - 1900);

      }

   const uint64_t year_factor = 10000000000;

   const uint64_t mon_factor  = 100000000;

   const uint64_t day_factor  = 1000000;

   const uint64_t hour_factor = 10000;

   const uint64_t min_factor  = 100;

   const uint64_t int_repr =

      year_factor * full_year +

      mon_factor * m_month +

      day_factor * m_day +

      hour_factor * m_hour +

      min_factor * m_minute +

      m_second;

   std::string repr = std::to_string(int_repr) + "Z";

   uint32_t desired_size = (m_tag == ASN1_Type::UtcTime) ? 13 : 15;

   while(repr.size() < desired_size)

      repr = "0" + repr;

   return repr;

   }

std::string ASN1_Time::readable_string() const

   {

   if(time_is_set() == false)

      throw Invalid_State("ASN1_Time::readable_string: No time set");

   // desired format: "%04d/%02d/%02d %02d:%02d:%02d UTC"

   std::stringstream output;

   output << std::setfill('0')

          << std::setw(4) << m_year << "/"

          << std::setw(2) << m_month << "/"

          << std::setw(2) << m_day

          << " "

          << std::setw(2) << m_hour << ":"

          << std::setw(2) << m_minute << ":"

          << std::setw(2) << m_second

          << " UTC";

   return output.str();

   }

bool ASN1_Time::time_is_set() const

   {

   return (m_year != 0);

   }

int32_t ASN1_Time::cmp(const ASN1_Time& other) const

   {

   if(time_is_set() == false)

      throw Invalid_State("ASN1_Time::cmp: No time set");

   const int32_t EARLIER = -1, LATER = 1, SAME_TIME = 0;

   if(m_year < other.m_year)     return EARLIER;

   if(m_year > other.m_year)     return LATER;

   if(m_month < other.m_month)   return EARLIER;

   if(m_month > other.m_month)   return LATER;

   if(m_day < other.m_day)       return EARLIER;

   if(m_day > other.m_day)       return LATER;

   if(m_hour < other.m_hour)     return EARLIER;

   if(m_hour > other.m_hour)     return LATER;

   if(m_minute < other.m_minute) return EARLIER;

   if(m_minute > other.m_minute) return LATER;

   if(m_second < other.m_second) return EARLIER;

   if(m_second > other.m_second) return LATER;

   return SAME_TIME;

   }

void ASN1_Time::set_to(const std::string& t_spec, ASN1_Type spec_tag)

   {

   BOTAN_ASSERT(spec_tag == ASN1_Type::UtcTime || spec_tag == ASN1_Type::GeneralizedTime, "Invalid tag.");

   if(spec_tag == ASN1_Type::GeneralizedTime)

      {

      BOTAN_ARG_CHECK(t_spec.size() == 15, "Invalid GeneralizedTime string");

      }

   else if(spec_tag == ASN1_Type::UtcTime)

      {

      BOTAN_ARG_CHECK(t_spec.size() == 13, "Invalid UTCTime string");

      }

   BOTAN_ARG_CHECK(t_spec.back() == 'Z', "Botan does not support ASN1 times with timezones other than Z");

   const size_t YEAR_SIZE = (spec_tag == ASN1_Type::UtcTime) ? 2 : 4;

   std::vector<std::string> params;

   std::string current;

   for(size_t j = 0; j != YEAR_SIZE; ++j)

      current += t_spec[j];

   params.push_back(current);

   current.clear();

   for(size_t j = YEAR_SIZE; j != t_spec.size() - 1; ++j)

      {

      current += t_spec[j];

      if(current.size() == 2)

         {

         params.push_back(current);

         current.clear();

         }

      }

   m_year   = to_u32bit(params[0]);

   m_month  = to_u32bit(params[1]);

   m_day    = to_u32bit(params[2]);

   m_hour   = to_u32bit(params[3]);

   m_minute = to_u32bit(params[4]);

   m_second = (params.size() == 6) ? to_u32bit(params[5]) : 0;

   m_tag    = spec_tag;

   if(spec_tag == ASN1_Type::UtcTime)

      {

      if(m_year >= 50) m_year += 1900;

      else             m_year += 2000;

      }

   if(!passes_sanity_check())

      throw Invalid_Argument("Time " + t_spec + " does not seem to be valid");

   }

/*

* Do a general sanity check on the time

*/

bool ASN1_Time::passes_sanity_check() const

   {

   // AppVeyor's trust store includes a cert with expiration date in 3016 ...

   if(m_year < 1950 || m_year > 3100)

      return false;

   if(m_month == 0 || m_month > 12)

      return false;

   const uint32_t days_in_month[12] = { 31, 28+1, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };

   if(m_day == 0 || m_day > days_in_month[m_month-1])

      return false;

   if(m_month == 2 && m_day == 29)

      {

      if(m_year % 4 != 0)

         return false; // not a leap year

      if(m_year % 100 == 0 && m_year % 400 != 0)

         return false;

      }

   if(m_hour >= 24 || m_minute >= 60 || m_second > 60)

      return false;

   if (m_tag == ASN1_Type::UtcTime)

      {

      /*

      UTCTime limits the value of components such that leap seconds

      are not covered. See "UNIVERSAL 23" in "Information technology

      Abstract Syntax Notation One (ASN.1): Specification of basic notation"

      http://www.itu.int/ITU-T/studygroups/com17/languages/

      */

      if(m_second > 59)

         {

         return false;

         }

      }

   return true;

   }

std::chrono::system_clock::time_point ASN1_Time::to_std_timepoint() const

   {

   return calendar_point(m_year, m_month, m_day, m_hour, m_minute, m_second).to_std_timepoint();

   }

uint64_t ASN1_Time::time_since_epoch() const

   {

   auto tp = this->to_std_timepoint();

   return std::chrono::duration_cast<std::chrono::seconds>(tp.time_since_epoch()).count();

   }

/*

* Compare two ASN1_Times for in various ways

*/

bool operator==(const ASN1_Time& t1, const ASN1_Time& t2)

   { return (t1.cmp(t2) == 0); }

bool operator!=(const ASN1_Time& t1, const ASN1_Time& t2)

   { return (t1.cmp(t2) != 0); }

bool operator<=(const ASN1_Time& t1, const ASN1_Time& t2)

   { return (t1.cmp(t2) <= 0); }

bool operator>=(const ASN1_Time& t1, const ASN1_Time& t2)

   { return (t1.cmp(t2) >= 0); }

bool operator<(const ASN1_Time& t1, const ASN1_Time& t2)

   { return (t1.cmp(t2) < 0); }

bool operator>(const ASN1_Time& t1, const ASN1_Time& t2)

   { return (t1.cmp(t2) > 0); }

}