/* Copyright (c) 2013-2018 Dovecot authors, see the included COPYING file */
#include "lib.h"
#include "str.h"
#include "utc-mktime.h"
#include "http-date.h"
#include <ctype.h>
/* RFC 7231, Section 7.1.1.1: Date/Time Formats
The defined syntax is as follows:
HTTP-date = IMF-fixdate / obs-date
Preferred format:
IMF-fixdate = day-name "," SP date1 SP time-of-day SP GMT
; fixed length/zone/capitalization subset of the format
; see Section 3.3 of [RFC5322]
day-name = %x4D.6F.6E ; "Mon", case-sensitive
/ %x54.75.65 ; "Tue", case-sensitive
/ %x57.65.64 ; "Wed", case-sensitive
/ %x54.68.75 ; "Thu", case-sensitive
/ %x46.72.69 ; "Fri", case-sensitive
/ %x53.61.74 ; "Sat", case-sensitive
/ %x53.75.6E ; "Sun", case-sensitive
date1 = day SP month SP year
; e.g., 02 Jun 1982
day = 2DIGIT
month = %x4A.61.6E ; "Jan", case-sensitive
/ %x46.65.62 ; "Feb", case-sensitive
/ %x4D.61.72 ; "Mar", case-sensitive
/ %x41.70.72 ; "Apr", case-sensitive
/ %x4D.61.79 ; "May", case-sensitive
/ %x4A.75.6E ; "Jun", case-sensitive
/ %x4A.75.6C ; "Jul", case-sensitive
/ %x41.75.67 ; "Aug", case-sensitive
/ %x53.65.70 ; "Sep", case-sensitive
/ %x4F.63.74 ; "Oct", case-sensitive
/ %x4E.6F.76 ; "Nov", case-sensitive
/ %x44.65.63 ; "Dec", case-sensitive
year = 4DIGIT
GMT = %x47.4D.54 ; "GMT", case-sensitive
time-of-day = hour ":" minute ":" second
; 00:00:00 - 23:59:60 (leap second)
hour = 2DIGIT
minute = 2DIGIT
second = 2DIGIT
Obsolete formats:
obs-date = rfc850-date / asctime-date
rfc850-date = day-name-l "," SP date2 SP time-of-day SP GMT
date2 = day "-" month "-" 2DIGIT
; e.g., 02-Jun-82
day-name-l = %x4D.6F.6E.64.61.79 ; "Monday", case-sensitive
/ %x54.75.65.73.64.61.79 ; "Tuesday", case-sensitive
/ %x57.65.64.6E.65.73.64.61.79 ; "Wednesday", case-sensitive
/ %x54.68.75.72.73.64.61.79 ; "Thursday", case-sensitive
/ %x46.72.69.64.61.79 ; "Friday", case-sensitive
/ %x53.61.74.75.72.64.61.79 ; "Saturday", case-sensitive
/ %x53.75.6E.64.61.79 ; "Sunday", case-sensitive
asctime-date = day-name SP date3 SP time-of-day SP year
date3 = month SP ( 2DIGIT / ( SP 1DIGIT ))
; e.g., Jun 2
*/
static const char *month_names[] = {
"Jan", "Feb", "Mar", "Apr", "May", "Jun",
"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
};
static const char *weekday_names[] = {
"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
};
static const char *weekday_names_long[] = {
"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"
};
struct http_date_parser {
const unsigned char *cur, *end;
struct tm tm;
int timezone_offset;
};
static inline int
http_date_parse_sp(struct http_date_parser *parser)
{
if (parser->cur >= parser->end)
return -1;
if (parser->cur[0] != ' ')
return 0;
parser->cur++;
return 1;
}
static inline int
http_date_parse_number(struct http_date_parser *parser,
int digits, int *number_r)
{
int i;
if (parser->cur >= parser->end || !i_isdigit(parser->cur[0]))
return 0;
*number_r = parser->cur[0] - '0';
parser->cur++;
for (i=0; i < digits-1; i++) {
if (parser->cur >= parser->end || !i_isdigit(parser->cur[0]))
return -1;
*number_r = ((*number_r) * 10) + parser->cur[0] - '0';
parser->cur++;
}
return 1;
}
static inline int
http_date_parse_word(struct http_date_parser *parser,
int maxchars, string_t **word_r)
{
string_t *word;
int i;
if (parser->cur >= parser->end || !i_isalpha(parser->cur[0]))
return 0;
word = t_str_new(maxchars);
str_append_c(word, parser->cur[0]);
parser->cur++;
for (i=0; i < maxchars-1; i++) {
if (parser->cur >= parser->end || !i_isalpha(parser->cur[0]))
break;
str_append_c(word, parser->cur[0]);
parser->cur++;
}
if (parser->cur < parser->end && i_isalpha(parser->cur[0]))
return -1;
*word_r = word;
return 1;
}
static inline int
http_date_parse_year(struct http_date_parser *parser)
{
/* year = 4DIGIT */
if (http_date_parse_number(parser, 4, &parser->tm.tm_year) <= 0)
return -1;
if (parser->tm.tm_year < 1900)
return -1;
parser->tm.tm_year -= 1900;
return 1;
}
static inline int
http_date_parse_month(struct http_date_parser *parser)
{
string_t *month;
int i;
if (http_date_parse_word(parser, 3, &month) <= 0 || str_len(month) != 3)
return -1;
for (i = 0; i < 12; i++) {
if (strcmp(month_names[i], str_c(month)) == 0) {
break;
}
}
if (i >= 12)
return -1;
parser->tm.tm_mon = i;
return 1;
}
static inline int
http_date_parse_day(struct http_date_parser *parser)
{
/* day = 2DIGIT */
if (http_date_parse_number(parser, 2, &parser->tm.tm_mday) <= 0)
return -1;
return 1;
}
static int
http_date_parse_time_of_day(struct http_date_parser *parser)
{
/* time-of-day = hour ":" minute ":" second
; 00:00:00 - 23:59:59
hour = 2DIGIT
minute = 2DIGIT
second = 2DIGIT
*/
/* hour = 2DIGIT */
if (http_date_parse_number(parser, 2, &parser->tm.tm_hour) <= 0)
return -1;
/* ":" */
if (parser->cur >= parser->end || parser->cur[0] != ':')
return -1;
parser->cur++;
/* minute = 2DIGIT */
if (http_date_parse_number(parser, 2, &parser->tm.tm_min) <= 0)
return -1;
/* ":" */
if (parser->cur >= parser->end || parser->cur[0] != ':')
return -1;
parser->cur++;
/* second = 2DIGIT */
if (http_date_parse_number(parser, 2, &parser->tm.tm_sec) <= 0)
return -1;
return 1;
}
static inline int
http_date_parse_time_gmt(struct http_date_parser *parser)
{
string_t *gmt;
/* Remaining: {...} SP time-of-day SP GMT
*/
/* SP time-of-day */
if (http_date_parse_sp(parser) <= 0)
return -1;
if (http_date_parse_time_of_day(parser) <= 0)
return -1;
/* SP GMT */
if (http_date_parse_sp(parser) <= 0)
return -1;
if (http_date_parse_word(parser, 3, &gmt) <= 0 ||
strcmp("GMT", str_c(gmt)) != 0)
return -1;
return 1;
}
static int
http_date_parse_format_imf_fixdate(struct http_date_parser *parser)
{
/*
IMF-fixdate = day-name "," SP date1 SP time-of-day SP GMT
; fixed length/zone/capitalization subset of the format
; see Section 3.3 of [RFC5322]
date1 = day SP month SP year
; e.g., 02 Jun 1982
Remaining: {...} SP day SP month SP year SP time-of-day SP GMT
*/
/* SP day */
if (http_date_parse_sp(parser) <= 0)
return -1;
if (http_date_parse_day(parser) <= 0)
return -1;
/* SP month */
if (http_date_parse_sp(parser) <= 0)
return -1;
if (http_date_parse_month(parser) <= 0)
return -1;
/* SP year */
if (http_date_parse_sp(parser) <= 0)
return -1;
if (http_date_parse_year(parser) <= 0)
return -1;
/* SP time-of-day SP GMT */
return http_date_parse_time_gmt(parser);
}
static int
http_date_parse_format_rfc850(struct http_date_parser *parser)
{
/*
rfc850-date = day-name-l "," SP date2 SP time-of-day SP GMT
date2 = day "-" month "-" 2DIGIT
; day-month-year (e.g., 02-Jun-82)
Remaining: "," SP day "-" month "-" 2DIGIT SP time-of-day SP GMT
*/
/* "," SP */
if (parser->cur >= parser->end || parser->cur[0] != ',')
return -1;
parser->cur++;
if (http_date_parse_sp(parser) <= 0)
return -1;
/* day */
if (http_date_parse_day(parser) <= 0)
return -1;
/* "-" */
if (parser->cur >= parser->end || parser->cur[0] != '-')
return -1;
parser->cur++;
/* month */
if (http_date_parse_month(parser) <= 0)
return -1;
/* "-" */
if (parser->cur >= parser->end || parser->cur[0] != '-')
return -1;
parser->cur++;
/* 2DIGIT */
if (http_date_parse_number(parser, 2, &parser->tm.tm_year) <= 0)
return -1;
if (parser->tm.tm_year < 70)
parser->tm.tm_year += 100;
/* SP time-of-day SP GMT */
return http_date_parse_time_gmt(parser);
}
static int
http_date_parse_format_asctime(struct http_date_parser *parser)
{
int ret;
/*
asctime-date = day-name SP date3 SP time-of-day SP year
date3 = month SP ( 2DIGIT / ( SP 1DIGIT ))
; month day (e.g., Jun 2)
Remaining: {...} month SP ( 2DIGIT / ( SP 1DIGIT )) SP time-of-day SP year
*/
/* month */
if (http_date_parse_month(parser) <= 0)
return -1;
/* SP */
if (http_date_parse_sp(parser) <= 0)
return -1;
/* SP 1DIGIT / 2DIGIT */
if ((ret=http_date_parse_sp(parser)) < 0)
return -1;
if (ret == 0) {
if (http_date_parse_number(parser, 2, &parser->tm.tm_mday) <= 0)
return -1;
} else {
if (http_date_parse_number(parser, 1, &parser->tm.tm_mday) <= 0)
return -1;
}
/* SP time-of-day */
if (http_date_parse_sp(parser) <= 0)
return -1;
if (http_date_parse_time_of_day(parser) <= 0)
return -1;
/* SP year */
if (http_date_parse_sp(parser) <= 0)
return -1;
return http_date_parse_year(parser);
}
static int
http_date_parse_format_any(struct http_date_parser *parser)
{
string_t *dayname;
int i;
/*
HTTP-date = IMF-fixdate / obs-date
IMF-fixdate = day-name "," SP date1 SP time-of-day SP GMT
; fixed length/zone/capitalization subset of the format
; see Section 3.3 of [RFC5322]
obs-date = rfc850-date / asctime-date
rfc850-date = day-name-l "," SP date2 SP time-of-day SP GMT
asctime-date = day-name SP date3 SP time-of-day SP year
*/
if (http_date_parse_word(parser, 9, &dayname) <= 0)
return -1;
if (str_len(dayname) > 3) {
/* rfc850-date */
for (i = 0; i < 7; i++) {
if (strcmp(weekday_names_long[i], str_c(dayname)) == 0) {
break;
}
}
if (i >= 7)
return -1;
return http_date_parse_format_rfc850(parser);
}
/* IMF-fixdate / asctime-date */
for (i = 0; i < 7; i++) {
if (strcmp(weekday_names[i], str_c(dayname)) == 0) {
break;
}
}
if (i >= 7 || parser->cur >= parser->end)
return -1;
if (parser->cur[0] == ' ') {
/* asctime-date */
parser->cur++;
return http_date_parse_format_asctime(parser);
}
if (parser->cur[0] != ',')
return -1;
/* IMF-fixdate */
parser->cur++;
return http_date_parse_format_imf_fixdate(parser);
}
bool http_date_parse(const unsigned char *data, size_t size,
time_t *timestamp_r)
{
struct http_date_parser parser;
time_t timestamp;
i_zero(&parser);
parser.cur = data;
parser.end = data + size;
if (http_date_parse_format_any(&parser) <= 0)
return FALSE;
if (parser.cur != parser.end)
return FALSE;
parser.tm.tm_isdst = -1;
timestamp = utc_mktime(&parser.tm);
if (timestamp == (time_t)-1)
return FALSE;
*timestamp_r = timestamp;
return TRUE;
}
bool http_date_parse_tm(const unsigned char *data, size_t size,
struct tm *tm_r)
{
time_t timestamp;
struct tm *tm;
if (!http_date_parse(data, size, &timestamp))
return FALSE;
tm = gmtime(&timestamp);
*tm_r = *tm;
return TRUE;
}
const char *http_date_create_tm(struct tm *tm)
{
return t_strdup_printf("%s, %02d %s %04d %02d:%02d:%02d GMT",
weekday_names[tm->tm_wday],
tm->tm_mday,
month_names[tm->tm_mon],
tm->tm_year+1900,
tm->tm_hour, tm->tm_min, tm->tm_sec);
}
const char *http_date_create(time_t timestamp)
{
struct tm *tm;
tm = gmtime(&timestamp);
return http_date_create_tm(tm);
}