1 // Copyright 2014 The PDFium Authors
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
6
7 #include "fxjs/fx_date_helpers.h"
8
9 #include <math.h>
10 #include <time.h>
11 #include <wctype.h>
12
13 #include <array>
14 #include <iterator>
15
16 #include "build/build_config.h"
17 #include "core/fxcrt/fx_extension.h"
18 #include "core/fxcrt/fx_system.h"
19 #include "fpdfsdk/cpdfsdk_helpers.h"
20
21 namespace fxjs {
22 namespace {
23
24 constexpr std::array<uint16_t, 12> kDaysMonth = {
25 {0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334}};
26
27 constexpr std::array<uint16_t, 12> kLeapDaysMonth = {
28 {0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335}};
29
Mod(double x,double y)30 double Mod(double x, double y) {
31 double r = fmod(x, y);
32 if (r < 0)
33 r += y;
34 return r;
35 }
36
GetLocalTZA()37 double GetLocalTZA() {
38 if (!IsPDFSandboxPolicyEnabled(FPDF_POLICY_MACHINETIME_ACCESS))
39 return 0;
40 time_t t = 0;
41 FXSYS_time(&t);
42 FXSYS_localtime(&t);
43 #if BUILDFLAG(IS_WIN)
44 // In gcc 'timezone' is a global variable declared in time.h. In VC++, that
45 // variable was removed in VC++ 2015, with _get_timezone replacing it.
46 long timezone = 0;
47 _get_timezone(&timezone);
48 #endif
49 return (double)(-(timezone * 1000));
50 }
51
GetDaylightSavingTA(double d)52 int GetDaylightSavingTA(double d) {
53 if (!IsPDFSandboxPolicyEnabled(FPDF_POLICY_MACHINETIME_ACCESS))
54 return 0;
55 time_t t = (time_t)(d / 1000);
56 struct tm* tmp = FXSYS_localtime(&t);
57 if (!tmp)
58 return 0;
59 if (tmp->tm_isdst > 0)
60 // One hour.
61 return (int)60 * 60 * 1000;
62 return 0;
63 }
64
IsLeapYear(int year)65 bool IsLeapYear(int year) {
66 return (year % 4 == 0) && ((year % 100 != 0) || (year % 400 != 0));
67 }
68
DayFromYear(int y)69 int DayFromYear(int y) {
70 return (int)(365 * (y - 1970.0) + floor((y - 1969.0) / 4) -
71 floor((y - 1901.0) / 100) + floor((y - 1601.0) / 400));
72 }
73
TimeFromYear(int y)74 double TimeFromYear(int y) {
75 return 86400000.0 * DayFromYear(y);
76 }
77
TimeFromYearMonth(int y,int m)78 double TimeFromYearMonth(int y, int m) {
79 const uint16_t month = IsLeapYear(y) ? kLeapDaysMonth[m] : kDaysMonth[m];
80 return TimeFromYear(y) + static_cast<double>(month) * 86400000;
81 }
82
Day(double t)83 int Day(double t) {
84 return static_cast<int>(floor(t / 86400000.0));
85 }
86
YearFromTime(double t)87 int YearFromTime(double t) {
88 // estimate the time.
89 int y = 1970 + static_cast<int>(t / (365.2425 * 86400000.0));
90 if (TimeFromYear(y) <= t) {
91 while (TimeFromYear(y + 1) <= t)
92 y++;
93 } else {
94 while (TimeFromYear(y) > t)
95 y--;
96 }
97 return y;
98 }
99
DayWithinYear(double t)100 int DayWithinYear(double t) {
101 int year = YearFromTime(t);
102 int day = Day(t);
103 return day - DayFromYear(year);
104 }
105
MonthFromTime(double t)106 int MonthFromTime(double t) {
107 // Check for negative |day| values and check for January.
108 int day = DayWithinYear(t);
109 if (day < 0)
110 return -1;
111 if (day < 31)
112 return 0;
113
114 if (IsLeapYear(YearFromTime(t)))
115 --day;
116
117 // Check for February onwards.
118 static constexpr std::array<int, 11> kCumulativeDaysInMonths = {
119 {59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365}};
120 for (size_t i = 0; i < std::size(kCumulativeDaysInMonths); ++i) {
121 if (day < kCumulativeDaysInMonths[i])
122 return static_cast<int>(i) + 1;
123 }
124
125 return -1;
126 }
127
DateFromTime(double t)128 int DateFromTime(double t) {
129 int day = DayWithinYear(t);
130 int year = YearFromTime(t);
131 int leap = IsLeapYear(year);
132 int month = MonthFromTime(t);
133 switch (month) {
134 case 0:
135 return day + 1;
136 case 1:
137 return day - 30;
138 case 2:
139 return day - 58 - leap;
140 case 3:
141 return day - 89 - leap;
142 case 4:
143 return day - 119 - leap;
144 case 5:
145 return day - 150 - leap;
146 case 6:
147 return day - 180 - leap;
148 case 7:
149 return day - 211 - leap;
150 case 8:
151 return day - 242 - leap;
152 case 9:
153 return day - 272 - leap;
154 case 10:
155 return day - 303 - leap;
156 case 11:
157 return day - 333 - leap;
158 default:
159 return 0;
160 }
161 }
162
FindSubWordLength(const WideString & str,size_t nStart)163 size_t FindSubWordLength(const WideString& str, size_t nStart) {
164 pdfium::span<const wchar_t> data = str.span();
165 size_t i = nStart;
166 while (i < data.size() && iswalnum(data[i]))
167 ++i;
168 return i - nStart;
169 }
170
171 } // namespace
172
173 const std::array<const char*, 12> kMonths = {{"Jan", "Feb", "Mar", "Apr", "May",
174 "Jun", "Jul", "Aug", "Sep", "Oct",
175 "Nov", "Dec"}};
176
177 const std::array<const char*, 12> kFullMonths = {
178 {"January", "February", "March", "April", "May", "June", "July", "August",
179 "September", "October", "November", "December"}};
180
181 static constexpr size_t KMonthAbbreviationLength = 3; // Anything in |kMonths|.
182 static constexpr size_t kLongestFullMonthLength = 9; // September
183
FX_GetDateTime()184 double FX_GetDateTime() {
185 if (!IsPDFSandboxPolicyEnabled(FPDF_POLICY_MACHINETIME_ACCESS))
186 return 0;
187
188 time_t t = FXSYS_time(nullptr);
189 struct tm* pTm = FXSYS_localtime(&t);
190 double t1 = TimeFromYear(pTm->tm_year + 1900);
191 return t1 + pTm->tm_yday * 86400000.0 + pTm->tm_hour * 3600000.0 +
192 pTm->tm_min * 60000.0 + pTm->tm_sec * 1000.0;
193 }
194
FX_GetYearFromTime(double dt)195 int FX_GetYearFromTime(double dt) {
196 return YearFromTime(dt);
197 }
198
FX_GetMonthFromTime(double dt)199 int FX_GetMonthFromTime(double dt) {
200 return MonthFromTime(dt);
201 }
202
FX_GetDayFromTime(double dt)203 int FX_GetDayFromTime(double dt) {
204 return DateFromTime(dt);
205 }
206
FX_GetHourFromTime(double dt)207 int FX_GetHourFromTime(double dt) {
208 return (int)Mod(floor(dt / (60 * 60 * 1000)), 24);
209 }
210
FX_GetMinFromTime(double dt)211 int FX_GetMinFromTime(double dt) {
212 return (int)Mod(floor(dt / (60 * 1000)), 60);
213 }
214
FX_GetSecFromTime(double dt)215 int FX_GetSecFromTime(double dt) {
216 return (int)Mod(floor(dt / 1000), 60);
217 }
218
FX_IsValidMonth(int m)219 bool FX_IsValidMonth(int m) {
220 return m >= 1 && m <= 12;
221 }
222
223 // TODO(thestig): Should this take the month into consideration?
FX_IsValidDay(int d)224 bool FX_IsValidDay(int d) {
225 return d >= 1 && d <= 31;
226 }
227
228 // TODO(thestig): Should 24 be allowed? Similarly, 60 for minutes and seconds.
FX_IsValid24Hour(int h)229 bool FX_IsValid24Hour(int h) {
230 return h >= 0 && h <= 24;
231 }
232
FX_IsValidMinute(int m)233 bool FX_IsValidMinute(int m) {
234 return m >= 0 && m <= 60;
235 }
236
FX_IsValidSecond(int s)237 bool FX_IsValidSecond(int s) {
238 return s >= 0 && s <= 60;
239 }
240
FX_LocalTime(double d)241 double FX_LocalTime(double d) {
242 return d + GetLocalTZA() + GetDaylightSavingTA(d);
243 }
244
FX_MakeDay(int nYear,int nMonth,int nDate)245 double FX_MakeDay(int nYear, int nMonth, int nDate) {
246 double y = static_cast<double>(nYear);
247 double m = static_cast<double>(nMonth);
248 double dt = static_cast<double>(nDate);
249 double ym = y + floor(m / 12);
250 double mn = Mod(m, 12);
251 double t = TimeFromYearMonth(static_cast<int>(ym), static_cast<int>(mn));
252 if (YearFromTime(t) != ym || MonthFromTime(t) != mn || DateFromTime(t) != 1)
253 return nan("");
254
255 return Day(t) + dt - 1;
256 }
257
FX_MakeTime(int nHour,int nMin,int nSec,int nMs)258 double FX_MakeTime(int nHour, int nMin, int nSec, int nMs) {
259 double h = static_cast<double>(nHour);
260 double m = static_cast<double>(nMin);
261 double s = static_cast<double>(nSec);
262 double milli = static_cast<double>(nMs);
263 return h * 3600000 + m * 60000 + s * 1000 + milli;
264 }
265
FX_MakeDate(double day,double time)266 double FX_MakeDate(double day, double time) {
267 if (!isfinite(day) || !isfinite(time))
268 return nan("");
269
270 return day * 86400000 + time;
271 }
272
FX_ParseStringInteger(const WideString & str,size_t nStart,size_t * pSkip,size_t nMaxStep)273 int FX_ParseStringInteger(const WideString& str,
274 size_t nStart,
275 size_t* pSkip,
276 size_t nMaxStep) {
277 int nRet = 0;
278 size_t nSkip = 0;
279 for (size_t i = nStart; i < str.GetLength(); ++i) {
280 if (i - nStart > 10)
281 break;
282
283 wchar_t c = str[i];
284 if (!FXSYS_IsDecimalDigit(c))
285 break;
286
287 nRet = nRet * 10 + FXSYS_DecimalCharToInt(c);
288 ++nSkip;
289 if (nSkip >= nMaxStep)
290 break;
291 }
292
293 *pSkip = nSkip;
294 return nRet;
295 }
296
FX_ParseDateUsingFormat(const WideString & value,const WideString & format,double * result)297 ConversionStatus FX_ParseDateUsingFormat(const WideString& value,
298 const WideString& format,
299 double* result) {
300 double dt = FX_GetDateTime();
301 if (format.IsEmpty() || value.IsEmpty()) {
302 *result = dt;
303 return ConversionStatus::kSuccess;
304 }
305
306 int nYear = FX_GetYearFromTime(dt);
307 int nMonth = FX_GetMonthFromTime(dt) + 1;
308 int nDay = FX_GetDayFromTime(dt);
309 int nHour = FX_GetHourFromTime(dt);
310 int nMin = FX_GetMinFromTime(dt);
311 int nSec = FX_GetSecFromTime(dt);
312 int nYearSub = 99; // nYear - 2000;
313 bool bPm = false;
314 bool bExit = false;
315 bool bBadFormat = false;
316 size_t i = 0;
317 size_t j = 0;
318
319 while (i < format.GetLength()) {
320 if (bExit)
321 break;
322
323 wchar_t c = format[i];
324 switch (c) {
325 case ':':
326 case '.':
327 case '-':
328 case '\\':
329 case '/':
330 i++;
331 j++;
332 break;
333
334 case 'y':
335 case 'm':
336 case 'd':
337 case 'H':
338 case 'h':
339 case 'M':
340 case 's':
341 case 't': {
342 size_t oldj = j;
343 size_t nSkip = 0;
344 size_t remaining = format.GetLength() - i - 1;
345
346 if (remaining == 0 || format[i + 1] != c) {
347 switch (c) {
348 case 'y':
349 i++;
350 j++;
351 break;
352 case 'm':
353 nMonth = FX_ParseStringInteger(value, j, &nSkip, 2);
354 i++;
355 j += nSkip;
356 break;
357 case 'd':
358 nDay = FX_ParseStringInteger(value, j, &nSkip, 2);
359 i++;
360 j += nSkip;
361 break;
362 case 'H':
363 nHour = FX_ParseStringInteger(value, j, &nSkip, 2);
364 i++;
365 j += nSkip;
366 break;
367 case 'h':
368 nHour = FX_ParseStringInteger(value, j, &nSkip, 2);
369 i++;
370 j += nSkip;
371 break;
372 case 'M':
373 nMin = FX_ParseStringInteger(value, j, &nSkip, 2);
374 i++;
375 j += nSkip;
376 break;
377 case 's':
378 nSec = FX_ParseStringInteger(value, j, &nSkip, 2);
379 i++;
380 j += nSkip;
381 break;
382 case 't':
383 bPm = (j < value.GetLength() && value[j] == 'p');
384 i++;
385 j++;
386 break;
387 }
388 } else if (remaining == 1 || format[i + 2] != c) {
389 switch (c) {
390 case 'y':
391 nYear = FX_ParseStringInteger(value, j, &nSkip, 2);
392 i += 2;
393 j += nSkip;
394 break;
395 case 'm':
396 nMonth = FX_ParseStringInteger(value, j, &nSkip, 2);
397 i += 2;
398 j += nSkip;
399 break;
400 case 'd':
401 nDay = FX_ParseStringInteger(value, j, &nSkip, 2);
402 i += 2;
403 j += nSkip;
404 break;
405 case 'H':
406 nHour = FX_ParseStringInteger(value, j, &nSkip, 2);
407 i += 2;
408 j += nSkip;
409 break;
410 case 'h':
411 nHour = FX_ParseStringInteger(value, j, &nSkip, 2);
412 i += 2;
413 j += nSkip;
414 break;
415 case 'M':
416 nMin = FX_ParseStringInteger(value, j, &nSkip, 2);
417 i += 2;
418 j += nSkip;
419 break;
420 case 's':
421 nSec = FX_ParseStringInteger(value, j, &nSkip, 2);
422 i += 2;
423 j += nSkip;
424 break;
425 case 't':
426 bPm = (j + 1 < value.GetLength() && value[j] == 'p' &&
427 value[j + 1] == 'm');
428 i += 2;
429 j += 2;
430 break;
431 }
432 } else if (remaining == 2 || format[i + 3] != c) {
433 switch (c) {
434 case 'm': {
435 bool bFind = false;
436 nSkip = FindSubWordLength(value, j);
437 if (nSkip == KMonthAbbreviationLength) {
438 WideString sMonth = value.Substr(j, KMonthAbbreviationLength);
439 for (size_t m = 0; m < std::size(kMonths); ++m) {
440 if (sMonth.EqualsASCIINoCase(kMonths[m])) {
441 nMonth = static_cast<int>(m) + 1;
442 i += 3;
443 j += nSkip;
444 bFind = true;
445 break;
446 }
447 }
448 }
449
450 if (!bFind) {
451 nMonth = FX_ParseStringInteger(value, j, &nSkip, 3);
452 i += 3;
453 j += nSkip;
454 }
455 } break;
456 case 'y':
457 break;
458 default:
459 i += 3;
460 j += 3;
461 break;
462 }
463 } else if (remaining == 3 || format[i + 4] != c) {
464 switch (c) {
465 case 'y':
466 nYear = FX_ParseStringInteger(value, j, &nSkip, 4);
467 j += nSkip;
468 i += 4;
469 break;
470 case 'm': {
471 bool bFind = false;
472 nSkip = FindSubWordLength(value, j);
473 if (nSkip <= kLongestFullMonthLength) {
474 WideString sMonth = value.Substr(j, nSkip);
475 sMonth.MakeLower();
476 for (size_t m = 0; m < std::size(kFullMonths); ++m) {
477 auto sFullMonths = WideString::FromASCII(kFullMonths[m]);
478 sFullMonths.MakeLower();
479 if (sFullMonths.Contains(sMonth.AsStringView())) {
480 nMonth = static_cast<int>(m) + 1;
481 i += 4;
482 j += nSkip;
483 bFind = true;
484 break;
485 }
486 }
487 }
488 if (!bFind) {
489 nMonth = FX_ParseStringInteger(value, j, &nSkip, 4);
490 i += 4;
491 j += nSkip;
492 }
493 } break;
494 default:
495 i += 4;
496 j += 4;
497 break;
498 }
499 } else {
500 if (j >= value.GetLength() || format[i] != value[j]) {
501 bBadFormat = true;
502 bExit = true;
503 }
504 i++;
505 j++;
506 }
507
508 if (oldj == j) {
509 bBadFormat = true;
510 bExit = true;
511 }
512 break;
513 }
514
515 default:
516 if (value.GetLength() <= j) {
517 bExit = true;
518 } else if (format[i] != value[j]) {
519 bBadFormat = true;
520 bExit = true;
521 }
522
523 i++;
524 j++;
525 break;
526 }
527 }
528
529 if (bBadFormat)
530 return ConversionStatus::kBadFormat;
531
532 if (bPm)
533 nHour += 12;
534
535 if (nYear >= 0 && nYear <= nYearSub)
536 nYear += 2000;
537
538 if (!FX_IsValidMonth(nMonth) || !FX_IsValidDay(nDay) ||
539 !FX_IsValid24Hour(nHour) || !FX_IsValidMinute(nMin) ||
540 !FX_IsValidSecond(nSec)) {
541 return ConversionStatus::kBadDate;
542 }
543
544 dt = FX_MakeDate(FX_MakeDay(nYear, nMonth - 1, nDay),
545 FX_MakeTime(nHour, nMin, nSec, 0));
546 if (isnan(dt))
547 return ConversionStatus::kBadDate;
548
549 *result = dt;
550 return ConversionStatus::kSuccess;
551 }
552
553 } // namespace fxjs
554