/* * http_date.c -- Routines for parsing and generating http dates * Created: Christopher Blizzard , 16-Aug-1998 * * Copyright (C) 1998 Free Software Foundation * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Library General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this library; if not, write to the Free * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include #include #include "http_date.h" static int month_from_string_short(const char *a_month); /* * date formats come in one of the following three flavors according to * rfc 2068 and later drafts: * * Sun, 06 Nov 1994 08:49:37 GMT ; RFC 822, updated by RFC 1123 * Sunday, 06-Nov-1994, 08:49:37 GMT ; RFC 850, updated by RFC 1036 * Sun Nov 6 08:49:37 1994 ; ANSI C's asctime() format * * the first format is preferred however all must be supported. */ time_t http_date_to_time(const char *a_date) { struct tm l_tm_time; time_t l_return = 0; char l_buf[12]; const char *l_start_date = NULL; int i = 0; /* make sure we can use it */ if (!a_date) return -1; memset(&l_tm_time, 0, sizeof(struct tm)); memset(l_buf, 0, 12); /* try to figure out which format it's in */ /* rfc 1123 */ if (a_date[3] == ',') { if (strlen(a_date) != 29) return -1; /* make sure that everything is legal */ if (a_date[4] != ' ') return -1; /* 06 */ if ((isdigit(a_date[5]) == 0) || (isdigit(a_date[6]) == 0)) return -1; /* Nov */ if ((l_tm_time.tm_mon = month_from_string_short(&a_date[8])) < 0) return -1; /* 1994 */ if ((isdigit(a_date[12]) == 0) || (isdigit(a_date[13]) == 0) || (isdigit(a_date[14]) == 0) || (isdigit(a_date[15]) == 0)) return -1; if (a_date[16] != ' ') return -1; /* 08:49:37 */ if ((isdigit(a_date[17]) == 0) || (isdigit(a_date[18]) == 0) || (a_date[19] != ':') || (isdigit(a_date[20]) == 0) || (isdigit(a_date[21]) == 0) || (a_date[22] != ':') || (isdigit(a_date[23]) == 0) || (isdigit(a_date[24]) == 0)) return -1; if (a_date[25] != ' ') return -1; /* GMT */ if (strncmp(&a_date[26], "GMT", 3) != 0) return -1; /* ok, it's valid. Do it */ /* parse out the day of the month */ l_tm_time.tm_mday += (a_date[5] - 0x30) * 10; l_tm_time.tm_mday += (a_date[6] - 0x30); /* already got the month from above */ /* parse out the year */ l_tm_time.tm_year += (a_date[12] - 0x30) * 1000; l_tm_time.tm_year += (a_date[13] - 0x30) * 100; l_tm_time.tm_year += (a_date[14] - 0x30) * 10; l_tm_time.tm_year += (a_date[15] - 0x30); l_tm_time.tm_year -= 1900; /* parse out the time */ l_tm_time.tm_hour += (a_date[17] - 0x30) * 10; l_tm_time.tm_hour += (a_date[18] - 0x30); l_tm_time.tm_min += (a_date[20] - 0x30) * 10; l_tm_time.tm_min += (a_date[21] - 0x30); l_tm_time.tm_sec += (a_date[23] - 0x30) * 10; l_tm_time.tm_sec += (a_date[24] - 0x30); /* ok, generate the result */ l_return = mktime(&l_tm_time); } /* ansi C */ else if (a_date[3] == ' ') { if (strlen(a_date) != 24) return -1; /* Nov */ if ((l_tm_time.tm_mon = month_from_string_short(&a_date[4])) < 0) return -1; if (a_date[7] != ' ') return -1; /* "10" or " 6" */ if (((a_date[8] != ' ') && (isdigit(a_date[8]) == 0)) || (isdigit(a_date[9]) == 0)) return -1; if (a_date[10] != ' ') return -1; /* 08:49:37 */ if ((isdigit(a_date[11]) == 0) || (isdigit(a_date[12]) == 0) || (a_date[13] != ':') || (isdigit(a_date[14]) == 0) || (isdigit(a_date[15]) == 0) || (a_date[16] != ':') || (isdigit(a_date[17]) == 0) || (isdigit(a_date[18]) == 0)) return -1; if (a_date[19] != ' ') return -1; /* 1994 */ if ((isdigit(a_date[20]) == 0) || (isdigit(a_date[21]) == 0) || (isdigit(a_date[22]) == 0) || (isdigit(a_date[23]) == 0)) return -1; /* looks good */ /* got the month from above */ /* parse out the day of the month */ if (a_date[8] != ' ') l_tm_time.tm_mday += (a_date[8] - 0x30) * 10; l_tm_time.tm_mday += (a_date[9] - 0x30); /* parse out the time */ l_tm_time.tm_hour += (a_date[11] - 0x30) * 10; l_tm_time.tm_hour += (a_date[12] - 0x30); l_tm_time.tm_min += (a_date[14] - 0x30) * 10; l_tm_time.tm_min += (a_date[15] - 0x30); l_tm_time.tm_sec += (a_date[17] - 0x30) * 10; l_tm_time.tm_sec += (a_date[18] - 0x30); /* parse out the year */ l_tm_time.tm_year += (a_date[20] - 0x30) * 1000; l_tm_time.tm_year += (a_date[21] - 0x30) * 100; l_tm_time.tm_year += (a_date[22] - 0x30) * 10; l_tm_time.tm_year += (a_date[23] - 0x30); l_tm_time.tm_year -= 1900; /* generate the result */ l_return = mktime(&l_tm_time); } /* must be the 1036... */ else { /* check to make sure we won't rn out of any bounds */ if (strlen(a_date) < 11) return -1; while (a_date[i]) { if (a_date[i] == ' ') { l_start_date = &a_date[i+1]; break; } i++; } /* check to make sure there was a space found */ if (l_start_date == NULL) return -1; /* check to make sure that we don't overrun anything */ if (strlen(l_start_date) != 22) return -1; /* make sure that the rest of the date was valid */ /* 06- */ if ((isdigit(l_start_date[0]) == 0) || (isdigit(l_start_date[1]) == 0) || (l_start_date[2] != '-')) return -1; /* Nov */ if ((l_tm_time.tm_mon = month_from_string_short(&l_start_date[3])) < 0) return -1; /* -94 */ if ((l_start_date[6] != '-') || (isdigit(l_start_date[7]) == 0) || (isdigit(l_start_date[8]) == 0)) return -1; if (l_start_date[9] != ' ') return -1; /* 08:49:37 */ if ((isdigit(l_start_date[10]) == 0) || (isdigit(l_start_date[11]) == 0) || (l_start_date[12] != ':') || (isdigit(l_start_date[13]) == 0) || (isdigit(l_start_date[14]) == 0) || (l_start_date[15] != ':') || (isdigit(l_start_date[16]) == 0) || (isdigit(l_start_date[17]) == 0)) return -1; if (l_start_date[18] != ' ') return -1; if (strncmp(&l_start_date[19], "GMT", 3) != 0) return -1; /* looks ok to parse */ /* parse out the day of the month */ l_tm_time.tm_mday += (l_start_date[0] - 0x30) * 10; l_tm_time.tm_mday += (l_start_date[1] - 0x30); /* have the month from above */ /* parse out the year */ l_tm_time.tm_year += (l_start_date[7] - 0x30) * 10; l_tm_time.tm_year += (l_start_date[8] - 0x30); /* check for y2k */ if (l_tm_time.tm_year < 20) l_tm_time.tm_year += 100; /* parse out the time */ l_tm_time.tm_hour += (l_start_date[10] - 0x30) * 10; l_tm_time.tm_hour += (l_start_date[11] - 0x30); l_tm_time.tm_min += (l_start_date[13] - 0x30) * 10; l_tm_time.tm_min += (l_start_date[14] - 0x30); l_tm_time.tm_sec += (l_start_date[16] - 0x30) * 10; l_tm_time.tm_sec += (l_start_date[17] - 0x30); /* generate the result */ l_return = mktime(&l_tm_time); } return l_return; } static int month_from_string_short(const char *a_month) { if (strncmp(a_month, "Jan", 3) == 0) return 0; if (strncmp(a_month, "Feb", 3) == 0) return 1; if (strncmp(a_month, "Mar", 3) == 0) return 2; if (strncmp(a_month, "Apr", 3) == 0) return 3; if (strncmp(a_month, "May", 3) == 0) return 4; if (strncmp(a_month, "Jun", 3) == 0) return 5; if (strncmp(a_month, "Jul", 3) == 0) return 6; if (strncmp(a_month, "Aug", 3) == 0) return 7; if (strncmp(a_month, "Sep", 3) == 0) return 8; if (strncmp(a_month, "Oct", 3) == 0) return 9; if (strncmp(a_month, "Nov", 3) == 0) return 10; if (strncmp(a_month, "Dec", 3) == 0) return 11; /* not a valid date */ return -1; }