diff options
Diffstat (limited to 'plugins/sudoers/gentime.c')
| -rw-r--r-- | plugins/sudoers/gentime.c | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/plugins/sudoers/gentime.c b/plugins/sudoers/gentime.c new file mode 100644 index 0000000..7575c37 --- /dev/null +++ b/plugins/sudoers/gentime.c @@ -0,0 +1,171 @@ +/* + * SPDX-License-Identifier: ISC + * + * Copyright (c) 2017, 2021 Todd C. Miller <Todd.Miller@sudo.ws> + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +/* + * This is an open source non-commercial project. Dear PVS-Studio, please check it. + * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com + */ + +#include <config.h> + +#include <stdio.h> +#include <stdlib.h> +#ifdef HAVE_STDBOOL_H +# include <stdbool.h> +#else +# include <compat/stdbool.h> +#endif /* HAVE_STDBOOL_H */ +#include <string.h> +#include <ctype.h> +#include <time.h> + +#include <sudo_compat.h> +#include <sudoers_debug.h> +#include <parse.h> + +/* Since timegm() is only used in one place we keep the macro local. */ +#ifndef HAVE_TIMEGM +# define timegm(_t) sudo_timegm(_t) +#endif + +/* + * Parse a timestamp in Generalized Time format as per RFC4517. + * E.g. yyyymmddHHMMSS.FZ or yyyymmddHHMMSS.F[+-]TZOFF + * where minutes, seconds and fraction are optional. + * Returns the time in Unix time format or -1 on error. + */ +time_t +parse_gentime(const char *timestr) +{ + char tcopy[sizeof("yyyymmddHHMMSS")]; + const char *cp; + time_t result; + struct tm tm; + size_t len; + int items, tzoff = 0; + bool islocal = false; + debug_decl(parse_gentime, SUDOERS_DEBUG_PARSER); + + /* Make a copy of the non-fractional time without zone for easy parsing. */ + len = strspn(timestr, "0123456789"); + if (len >= sizeof(tcopy) || len < sizeof("yyyymmddHH") -1 || (len & 1)) { + sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO, + "unable to parse general time string %s", timestr); + debug_return_time_t(-1); + } + memcpy(tcopy, timestr, len); + tcopy[len] = '\0'; + + /* Parse general time, ignoring the timezone for now. */ + memset(&tm, 0, sizeof(tm)); + items = sscanf(tcopy, "%4d%2d%2d%2d%2d%2d", &tm.tm_year, &tm.tm_mon, + &tm.tm_mday, &tm.tm_hour, &tm.tm_min, &tm.tm_sec); + if (items == EOF || items < 4) { + sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO, + "only parsed %d items in general time string %s", items, timestr); + debug_return_time_t(-1); + } + + /* Parse optional fractional hours/minute/second if present. */ + cp = timestr + len; + if ((cp[0] == '.' || cp[0] == ',') && isdigit((unsigned char)cp[1])) { + int frac = cp[1] - '0'; + switch (items) { + case 4: + /* convert fractional hour -> minutes */ + tm.tm_min += 60 / 10 * frac; + break; + case 5: + /* convert fractional minute -> seconds */ + tm.tm_sec += 60 / 10 * frac; + break; + case 6: + /* ignore fractional second */ + break; + } + cp += 2; /* skip over radix and fraction */ + } + + /* Parse optional time zone. */ + switch (*cp) { + case '-': + case '+': { + int hour = 0, min = 0; + + /* No DST */ + tm.tm_isdst = 0; + /* time zone offset must be hh or hhmm */ + len = strspn(cp + 1, "0123456789"); + if (len != 2 && len != 4) { + sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO, + "unable to parse time zone offset in %s, bad tz offset", + timestr); + debug_return_time_t(-1); + } + /* parse time zone offset */ + items = sscanf(cp + 1, "%2d%2d", &hour, &min); + if (items == EOF || items < 1) { + sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO, + "unable to parse time zone offset in %s, items %d", + timestr, items); + debug_return_time_t(-1); + } + if (*cp == '-') + tzoff = -((hour * 60) + min) * 60; + else + tzoff = ((hour * 60) + min) * 60; + cp += 1 + (items * 2); + break; + } + case 'Z': + /* GMT/UTC, no DST */ + tm.tm_isdst = 0; + cp++; + break; + case '\0': + /* no zone specified, use local time */ + tm.tm_isdst = -1; + islocal = true; + break; + default: + sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO, + "unable to parse general time string %s", timestr); + debug_return_time_t(-1); + } + if (*cp != '\0') { + sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO, + "trailing garbage in general time string %s", timestr); + debug_return_time_t(-1); + } + + /* Adjust from Generalized Time to struct tm */ + tm.tm_year -= 1900; + tm.tm_mon--; + + if (islocal) { + result = mktime(&tm); + } else { + result = timegm(&tm); + if (result != -1) { + /* Adjust time based on supplied GMT offset. */ + result -= tzoff; + } + } + + debug_return_time_t(result); +} |