Line data    Source code

       1              : /*
       2              :  *
       3              :  *    Copyright (c) 2022 Project CHIP Authors
       4              :  *    All rights reserved.
       5              :  *
       6              :  *    Licensed under the Apache License, Version 2.0 (the "License");
       7              :  *    you may not use this file except in compliance with the License.
       8              :  *    You may obtain a copy of the License at
       9              :  *
      10              :  *        http://www.apache.org/licenses/LICENSE-2.0
      11              :  *
      12              :  *    Unless required by applicable law or agreed to in writing, software
      13              :  *    distributed under the License is distributed on an "AS IS" BASIS,
      14              :  *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      15              :  *    See the License for the specific language governing permissions and
      16              :  *    limitations under the License.
      17              :  */
      18              : 
      19              : /**
      20              :  *    @file
      21              :  *      This file implements Abstract Syntax Notation One (ASN.1) Time functions.
      22              :  *
      23              :  */
      24              : 
      25              : #include <getopt.h>
      26              : #include <inttypes.h>
      27              : #include <limits.h>
      28              : #include <memory>
      29              : #include <stdint.h>
      30              : #include <string.h>
      31              : #include <unistd.h>
      32              : 
      33              : #include <ctype.h>
      34              : #include <stdio.h>
      35              : 
      36              : #include <lib/asn1/ASN1.h>
      37              : #include <lib/support/TimeUtils.h>
      38              : 
      39              : namespace chip {
      40              : namespace ASN1 {
      41              : 
      42              : namespace {
      43              : 
      44              : /**
      45              :  * @brief Parses the two first characters C-string interpreting its content as a two base-10 digits number.
      46              :  *        The C-string pointer is advansed by two characters.
      47              :  */
      48         2316 : uint8_t atoi2(const char *& buf)
      49              : {
      50         2316 :     uint8_t val = static_cast<uint8_t>((buf[0] - '0') * 10 + (buf[1] - '0'));
      51         2316 :     buf += 2;
      52         2316 :     return val;
      53              : }
      54              : 
      55              : /**
      56              :  * @brief Converts two low significan base-10 digits of an integer value (val % 100) to a two character C-string.
      57              :  *        The C-string pointer is advansed by two characters.
      58              :  */
      59        22112 : void itoa2(uint32_t val, char *& buf)
      60              : {
      61        22112 :     buf[1] = static_cast<char>('0' + (val % 10));
      62        22112 :     val /= 10;
      63        22112 :     buf[0] = static_cast<char>('0' + (val % 10));
      64        22112 :     buf += 2;
      65        22112 : }
      66              : 
      67              : } // anonymous namespace
      68              : 
      69          390 : CHIP_ERROR ASN1UniversalTime::ImportFrom_ASN1_TIME_string(const CharSpan & asn1_time)
      70              : {
      71          390 :     const char * p    = asn1_time.data();
      72          390 :     const size_t size = asn1_time.size();
      73              : 
      74          390 :     VerifyOrReturnError(p != nullptr, ASN1_ERROR_INVALID_STATE);
      75          390 :     VerifyOrReturnError(size == kASN1UTCTimeStringLength || size == kASN1GeneralizedTimeStringLength,
      76              :                         ASN1_ERROR_UNSUPPORTED_ENCODING);
      77          387 :     VerifyOrReturnError(p[size - 1] == 'Z', ASN1_ERROR_UNSUPPORTED_ENCODING);
      78         5021 :     for (size_t i = 0; i < size - 1; i++)
      79              :     {
      80         4636 :         VerifyOrReturnError(isdigit(p[i]), ASN1_ERROR_INVALID_ENCODING);
      81              :     }
      82              : 
      83          385 :     if (size == kASN1GeneralizedTimeStringLength)
      84              :     {
      85            6 :         Year = static_cast<uint16_t>(atoi2(p) * 100 + atoi2(p));
      86              :     }
      87              :     else
      88              :     {
      89          379 :         Year = atoi2(p);
      90          379 :         Year = static_cast<uint16_t>(Year + ((Year >= 50) ? 1900 : 2000));
      91              :     }
      92              : 
      93          385 :     Month  = atoi2(p);
      94          385 :     Day    = atoi2(p);
      95          385 :     Hour   = atoi2(p);
      96          385 :     Minute = atoi2(p);
      97          385 :     Second = atoi2(p);
      98              : 
      99          385 :     VerifyOrReturnError(Month > 0 && Month <= kMonthsPerYear, ASN1_ERROR_INVALID_ENCODING);
     100          383 :     VerifyOrReturnError(Day > 0 && Day <= kMaxDaysPerMonth, ASN1_ERROR_INVALID_ENCODING);
     101          381 :     VerifyOrReturnError(Hour < kHoursPerDay, ASN1_ERROR_INVALID_ENCODING);
     102          380 :     VerifyOrReturnError(Minute < kMinutesPerHour, ASN1_ERROR_INVALID_ENCODING);
     103          379 :     VerifyOrReturnError(Second < kSecondsPerMinute, ASN1_ERROR_INVALID_ENCODING);
     104              : 
     105          378 :     return CHIP_NO_ERROR;
     106              : }
     107              : 
     108         3683 : CHIP_ERROR ASN1UniversalTime::ExportTo_ASN1_TIME_string(MutableCharSpan & asn1_time) const
     109              : {
     110         3683 :     char * p = asn1_time.data();
     111              : 
     112         3683 :     VerifyOrReturnError(p != nullptr, ASN1_ERROR_INVALID_STATE);
     113              : 
     114              :     // X.509/RFC5280 mandates that times before 2050 UTC must be encoded as ASN.1 UTCTime values, while
     115              :     // times equal or greater than 2050 must be encoded as GeneralizedTime values.  The only difference
     116              :     // (in the context of X.509 DER) is that GeneralizedTimes are encoded with a 4 digit year, while
     117              :     // UTCTimes are encoded with a two-digit year.
     118         3683 :     if (Year < 1950 || Year >= 2050)
     119              :     {
     120           14 :         VerifyOrReturnError(asn1_time.size() >= kASN1GeneralizedTimeStringLength, ASN1_ERROR_UNDERRUN);
     121           14 :         itoa2(Year / 100, p);
     122              :     }
     123              :     else
     124              :     {
     125         3669 :         VerifyOrReturnError(asn1_time.size() >= kASN1UTCTimeStringLength, ASN1_ERROR_UNDERRUN);
     126              :     }
     127              : 
     128         3683 :     itoa2(Year, p);
     129         3683 :     itoa2(Month, p);
     130         3683 :     itoa2(Day, p);
     131         3683 :     itoa2(Hour, p);
     132         3683 :     itoa2(Minute, p);
     133         3683 :     itoa2(Second, p);
     134         3683 :     *p = 'Z';
     135              : 
     136         3683 :     asn1_time.reduce_size(static_cast<size_t>(p - asn1_time.data() + 1));
     137              : 
     138         3683 :     return CHIP_NO_ERROR;
     139              : }
     140              : 
     141          110 : bool ASN1UniversalTime::ExportTo_UnixTime(uint32_t & unixEpoch)
     142              : {
     143          110 :     return CalendarTimeToSecondsSinceUnixEpoch(Year, Month, Day, Hour, Minute, Second, unixEpoch);
     144              : }
     145              : 
     146              : } // namespace ASN1
     147              : } // namespace chip