From 33afcbd75f3af7ea6c9a305b5acde0895e4466a4 Mon Sep 17 00:00:00 2001 From: Yoshua Wuyts Date: Fri, 7 Aug 2020 21:35:20 +0200 Subject: [PATCH] add http date parser / encoder helpers --- LICENSE-APACHE | 1 + LICENSE-MIT | 1 + src/utils/date.rs | 478 +++++++++++++++++++++++++++++++++ src/{utils.rs => utils/mod.rs} | 4 + 4 files changed, 484 insertions(+) create mode 100644 src/utils/date.rs rename src/{utils.rs => utils/mod.rs} (78%) diff --git a/LICENSE-APACHE b/LICENSE-APACHE index 1fe151f..7fafeec 100644 --- a/LICENSE-APACHE +++ b/LICENSE-APACHE @@ -176,6 +176,7 @@ END OF TERMS AND CONDITIONS Copyright 2019 Yoshua Wuyts + Copyright 2016-2018 Michael Tilli (Pyfisch) & `httpdate` contributors Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. diff --git a/LICENSE-MIT b/LICENSE-MIT index c1adf76..e9d8e33 100644 --- a/LICENSE-MIT +++ b/LICENSE-MIT @@ -3,6 +3,7 @@ The MIT License (MIT) Copyright (c) 2019 Yoshua Wuyts Copyright (c) 2017 http-rs authors Copyright (c) 2020 Jacob Brown +Copyright (c) 2016-2018 Michael Tilli (Pyfisch) & `httpdate` contributors Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal diff --git a/src/utils/date.rs b/src/utils/date.rs new file mode 100644 index 0000000..8ddb86f --- /dev/null +++ b/src/utils/date.rs @@ -0,0 +1,478 @@ +use std::fmt::{self, Display, Formatter}; +use std::str::{from_utf8, FromStr}; +use std::time::{Duration, SystemTime, UNIX_EPOCH}; + +use crate::{bail, ensure, format_err}; + +const IMF_FIXDATE_LENGTH: usize = 29; +const RFC850_MAX_LENGTH: usize = 23; +const ASCTIME_LENGTH: usize = 24; + +const YEAR_9999_SECONDS: u64 = 253402300800; +const SECONDS_IN_DAY: u64 = 86400; +const SECONDS_IN_HOUR: u64 = 3600; + +/// Format using the `Display` trait. +/// Convert timestamp into/from `SytemTime` to use. +/// Supports comparison and sorting. +#[derive(Copy, Clone, Debug, Eq, Ord)] +pub(crate) struct HttpDate { + /// 0...59 + second: u8, + /// 0...59 + minute: u8, + /// 0...23 + hour: u8, + /// 1...31 + day: u8, + /// 1...12 + month: u8, + /// 1970...9999 + year: u16, + /// 1...7 + week_day: u8, +} + +/// Parse a date from an HTTP header field. +/// +/// Supports the preferred IMF-fixdate and the legacy RFC 805 and +/// ascdate formats. Two digit years are mapped to dates between +/// 1970 and 2069. +pub(crate) fn parse_http_date(s: &str) -> crate::Result { + s.parse::().map(|d| d.into()) +} + +/// Format a date to be used in a HTTP header field. +/// +/// Dates are formatted as IMF-fixdate: `Fri, 15 May 2015 15:34:21 GMT`. +pub(crate) fn fmt_http_date(d: SystemTime) -> String { + format!("{}", HttpDate::from(d)) +} + +impl HttpDate { + fn is_valid(self) -> bool { + self.second < 60 + && self.minute < 60 + && self.hour < 24 + && self.day > 0 + && self.day < 32 + && self.month > 0 + && self.month <= 12 + && self.year >= 1970 + && self.year <= 9999 + && self.week_day >= 1 + && self.week_day < 8 + } +} + +fn parse_imf_fixdate(s: &[u8]) -> crate::Result { + // Example: `Sun, 06 Nov 1994 08:49:37 GMT` + if s.len() != IMF_FIXDATE_LENGTH + || &s[25..] != b" GMT" + || s[16] != b' ' + || s[19] != b':' + || s[22] != b':' + { + bail!("Date time not in imf fixdate format"); + } + Ok(HttpDate { + second: from_utf8(&s[23..25])?.parse()?, + minute: from_utf8(&s[20..22])?.parse()?, + hour: from_utf8(&s[17..19])?.parse()?, + day: from_utf8(&s[5..7])?.parse()?, + month: match &s[7..12] { + b" Jan " => 1, + b" Feb " => 2, + b" Mar " => 3, + b" Apr " => 4, + b" May " => 5, + b" Jun " => 6, + b" Jul " => 7, + b" Aug " => 8, + b" Sep " => 9, + b" Oct " => 10, + b" Nov " => 11, + b" Dec " => 12, + _ => bail!("Invalid Month"), + }, + year: from_utf8(&s[12..16])?.parse()?, + week_day: match &s[..5] { + b"Mon, " => 1, + b"Tue, " => 2, + b"Wed, " => 3, + b"Thu, " => 4, + b"Fri, " => 5, + b"Sat, " => 6, + b"Sun, " => 7, + _ => bail!("Invalid Day"), + }, + }) +} + +fn parse_rfc850_date(s: &[u8]) -> crate::Result { + // Example: `Sunday, 06-Nov-94 08:49:37 GMT` + ensure!( + s.len() >= RFC850_MAX_LENGTH, + "Date time not in rfc850 format" + ); + + fn week_day<'a>(s: &'a [u8], week_day: u8, name: &'static [u8]) -> Option<(u8, &'a [u8])> { + if &s[0..name.len()] == name { + return Some((week_day, &s[name.len()..])); + } + None + } + let (week_day, s) = week_day(s, 1, b"Monday, ") + .or_else(|| week_day(s, 2, b"Tuesday, ")) + .or_else(|| week_day(s, 3, b"Wednesday, ")) + .or_else(|| week_day(s, 4, b"Thursday, ")) + .or_else(|| week_day(s, 5, b"Friday, ")) + .or_else(|| week_day(s, 6, b"Saturday, ")) + .or_else(|| week_day(s, 7, b"Sunday, ")) + .ok_or_else(|| format_err!("Invalid day"))?; + if s.len() != 22 || s[12] != b':' || s[15] != b':' || &s[18..22] != b" GMT" { + bail!("Date time not in rfc950 fmt"); + } + let mut year = from_utf8(&s[7..9])?.parse::()?; + if year < 70 { + year += 2000; + } else { + year += 1900; + } + Ok(HttpDate { + second: from_utf8(&s[16..18])?.parse()?, + minute: from_utf8(&s[13..15])?.parse()?, + hour: from_utf8(&s[10..12])?.parse()?, + day: from_utf8(&s[0..2])?.parse()?, + month: match &s[2..7] { + b"-Jan-" => 1, + b"-Feb-" => 2, + b"-Mar-" => 3, + b"-Apr-" => 4, + b"-May-" => 5, + b"-Jun-" => 6, + b"-Jul-" => 7, + b"-Aug-" => 8, + b"-Sep-" => 9, + b"-Oct-" => 10, + b"-Nov-" => 11, + b"-Dec-" => 12, + _ => bail!("Invalid month"), + }, + year, + week_day, + }) +} + +fn parse_asctime(s: &[u8]) -> crate::Result { + // Example: `Sun Nov 6 08:49:37 1994` + if s.len() != ASCTIME_LENGTH || s[10] != b' ' || s[13] != b':' || s[16] != b':' || s[19] != b' ' + { + bail!("Date time not in asctime format"); + } + Ok(HttpDate { + second: from_utf8(&s[17..19])?.parse()?, + minute: from_utf8(&s[14..16])?.parse()?, + hour: from_utf8(&s[11..13])?.parse()?, + day: { + let x = &s[8..10]; + from_utf8(if x[0] == b' ' { &x[1..2] } else { x })?.parse()? + }, + month: match &s[4..8] { + b"Jan " => 1, + b"Feb " => 2, + b"Mar " => 3, + b"Apr " => 4, + b"May " => 5, + b"Jun " => 6, + b"Jul " => 7, + b"Aug " => 8, + b"Sep " => 9, + b"Oct " => 10, + b"Nov " => 11, + b"Dec " => 12, + _ => bail!("Invalid month"), + }, + year: from_utf8(&s[20..24])?.parse()?, + week_day: match &s[0..4] { + b"Mon " => 1, + b"Tue " => 2, + b"Wed " => 3, + b"Thu " => 4, + b"Fri " => 5, + b"Sat " => 6, + b"Sun " => 7, + _ => bail!("Invalid day"), + }, + }) +} + +impl From for HttpDate { + fn from(system_time: SystemTime) -> Self { + let dur = system_time + .duration_since(UNIX_EPOCH) + .expect("all times should be after the epoch"); + let secs_since_epoch = dur.as_secs(); + + if secs_since_epoch >= YEAR_9999_SECONDS { + // year 9999 + panic!("date must be before year 9999"); + } + + /* 2000-03-01 (mod 400 year, immediately after feb29 */ + const LEAPOCH: i64 = 11017; + const DAYS_PER_400Y: i64 = 365 * 400 + 97; + const DAYS_PER_100Y: i64 = 365 * 100 + 24; + const DAYS_PER_4Y: i64 = 365 * 4 + 1; + + let days = (secs_since_epoch / SECONDS_IN_DAY) as i64 - LEAPOCH; + let secs_of_day = secs_since_epoch % SECONDS_IN_DAY; + + let mut qc_cycles = days / DAYS_PER_400Y; + let mut remdays = days % DAYS_PER_400Y; + + if remdays < 0 { + remdays += DAYS_PER_400Y; + qc_cycles -= 1; + } + + let mut c_cycles = remdays / DAYS_PER_100Y; + if c_cycles == 4 { + c_cycles -= 1; + } + remdays -= c_cycles * DAYS_PER_100Y; + + let mut q_cycles = remdays / DAYS_PER_4Y; + if q_cycles == 25 { + q_cycles -= 1; + } + remdays -= q_cycles * DAYS_PER_4Y; + + let mut remyears = remdays / 365; + if remyears == 4 { + remyears -= 1; + } + remdays -= remyears * 365; + + let mut year = 2000 + remyears + 4 * q_cycles + 100 * c_cycles + 400 * qc_cycles; + + let months = [31, 30, 31, 30, 31, 31, 30, 31, 30, 31, 31, 29]; + let mut month = 0; + for month_len in months.iter() { + month += 1; + if remdays < *month_len { + break; + } + remdays -= *month_len; + } + let mday = remdays + 1; + let month = if month + 2 > 12 { + year += 1; + month - 10 + } else { + month + 2 + }; + + let mut week_day = (3 + days) % 7; + if week_day <= 0 { + week_day += 7 + }; + + HttpDate { + second: (secs_of_day % 60) as u8, + minute: ((secs_of_day % SECONDS_IN_HOUR) / 60) as u8, + hour: (secs_of_day / SECONDS_IN_HOUR) as u8, + day: mday as u8, + month: month as u8, + year: year as u16, + week_day: week_day as u8, + } + } +} + +impl From for SystemTime { + fn from(http_date: HttpDate) -> Self { + let leap_years = ((http_date.year - 1) - 1968) / 4 - ((http_date.year - 1) - 1900) / 100 + + ((http_date.year - 1) - 1600) / 400; + let mut ydays = match http_date.month { + 1 => 0, + 2 => 31, + 3 => 59, + 4 => 90, + 5 => 120, + 6 => 151, + 7 => 181, + 8 => 212, + 9 => 243, + 10 => 273, + 11 => 304, + 12 => 334, + _ => unreachable!(), + } + http_date.day as u64 + - 1; + if is_leap_year(http_date.year) && http_date.month > 2 { + ydays += 1; + } + let days = (http_date.year as u64 - 1970) * 365 + leap_years as u64 + ydays; + UNIX_EPOCH + + Duration::from_secs( + http_date.second as u64 + + http_date.minute as u64 * 60 + + http_date.hour as u64 * SECONDS_IN_HOUR + + days * SECONDS_IN_DAY, + ) + } +} + +impl FromStr for HttpDate { + type Err = crate::Error; + + fn from_str(s: &str) -> Result { + ensure!(s.is_ascii(), "String slice is not valid ASCII"); + let x = s.trim().as_bytes(); + let date = parse_imf_fixdate(x) + .or_else(|_| parse_rfc850_date(x)) + .or_else(|_| parse_asctime(x))?; + ensure!(date.is_valid(), "Invalid date time"); + Ok(date) + } +} + +impl Display for HttpDate { + fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result { + let week_day = match self.week_day { + 1 => b"Mon", + 2 => b"Tue", + 3 => b"Wed", + 4 => b"Thu", + 5 => b"Fri", + 6 => b"Sat", + 7 => b"Sun", + _ => unreachable!(), + }; + let month = match self.month { + 1 => b"Jan", + 2 => b"Feb", + 3 => b"Mar", + 4 => b"Apr", + 5 => b"May", + 6 => b"Jun", + 7 => b"Jul", + 8 => b"Aug", + 9 => b"Sep", + 10 => b"Oct", + 11 => b"Nov", + 12 => b"Dec", + _ => unreachable!(), + }; + let mut buf: [u8; 29] = [ + // Too long to write as: b"Thu, 01 Jan 1970 00:00:00 GMT" + b' ', b' ', b' ', b',', b' ', b'0', b'0', b' ', b' ', b' ', b' ', b' ', b'0', b'0', + b'0', b'0', b' ', b'0', b'0', b':', b'0', b'0', b':', b'0', b'0', b' ', b'G', b'M', + b'T', + ]; + buf[0] = week_day[0]; + buf[1] = week_day[1]; + buf[2] = week_day[2]; + buf[5] = b'0' + (self.day / 10) as u8; + buf[6] = b'0' + (self.day % 10) as u8; + buf[8] = month[0]; + buf[9] = month[1]; + buf[10] = month[2]; + buf[12] = b'0' + (self.year / 1000) as u8; + buf[13] = b'0' + (self.year / 100 % 10) as u8; + buf[14] = b'0' + (self.year / 10 % 10) as u8; + buf[15] = b'0' + (self.year % 10) as u8; + buf[17] = b'0' + (self.hour / 10) as u8; + buf[18] = b'0' + (self.hour % 10) as u8; + buf[20] = b'0' + (self.minute / 10) as u8; + buf[21] = b'0' + (self.minute % 10) as u8; + buf[23] = b'0' + (self.second / 10) as u8; + buf[24] = b'0' + (self.second % 10) as u8; + f.write_str(from_utf8(&buf[..]).unwrap()) + } +} + +impl PartialEq for HttpDate { + fn eq(&self, other: &HttpDate) -> bool { + SystemTime::from(*self) == SystemTime::from(*other) + } +} + +impl PartialOrd for HttpDate { + fn partial_cmp(&self, other: &HttpDate) -> Option { + SystemTime::from(*self).partial_cmp(&SystemTime::from(*other)) + } +} + +fn is_leap_year(year: u16) -> bool { + year % 4 == 0 && (year % 100 != 0 || year % 400 == 0) +} + +#[cfg(test)] +mod tests { + use std::time::{Duration, UNIX_EPOCH}; + + use super::{fmt_http_date, parse_http_date, HttpDate, SECONDS_IN_DAY, SECONDS_IN_HOUR}; + + #[test] + fn test_rfc_example() { + let d = UNIX_EPOCH + Duration::from_secs(784111777); + assert_eq!( + d, + parse_http_date("Sun, 06 Nov 1994 08:49:37 GMT").expect("#1") + ); + assert_eq!( + d, + parse_http_date("Sunday, 06-Nov-94 08:49:37 GMT").expect("#2") + ); + assert_eq!(d, parse_http_date("Sun Nov 6 08:49:37 1994").expect("#3")); + } + + #[test] + fn test2() { + let d = UNIX_EPOCH + Duration::from_secs(1475419451); + assert_eq!( + d, + parse_http_date("Sun, 02 Oct 2016 14:44:11 GMT").expect("#1") + ); + assert!(parse_http_date("Sun Nov 10 08:00:00 1000").is_err()); + assert!(parse_http_date("Sun Nov 10 08*00:00 2000").is_err()); + assert!(parse_http_date("Sunday, 06-Nov-94 08+49:37 GMT").is_err()); + } + + #[test] + fn test3() { + let mut d = UNIX_EPOCH; + assert_eq!(d, parse_http_date("Thu, 01 Jan 1970 00:00:00 GMT").unwrap()); + d += Duration::from_secs(SECONDS_IN_HOUR); + assert_eq!(d, parse_http_date("Thu, 01 Jan 1970 01:00:00 GMT").unwrap()); + d += Duration::from_secs(SECONDS_IN_DAY); + assert_eq!(d, parse_http_date("Fri, 02 Jan 1970 01:00:00 GMT").unwrap()); + d += Duration::from_secs(2592000); + assert_eq!(d, parse_http_date("Sun, 01 Feb 1970 01:00:00 GMT").unwrap()); + d += Duration::from_secs(2592000); + assert_eq!(d, parse_http_date("Tue, 03 Mar 1970 01:00:00 GMT").unwrap()); + d += Duration::from_secs(31536005); + assert_eq!(d, parse_http_date("Wed, 03 Mar 1971 01:00:05 GMT").unwrap()); + d += Duration::from_secs(15552000); + assert_eq!(d, parse_http_date("Mon, 30 Aug 1971 01:00:05 GMT").unwrap()); + d += Duration::from_secs(6048000); + assert_eq!(d, parse_http_date("Mon, 08 Nov 1971 01:00:05 GMT").unwrap()); + d += Duration::from_secs(864000000); + assert_eq!(d, parse_http_date("Fri, 26 Mar 1999 01:00:05 GMT").unwrap()); + } + + #[test] + fn test_fmt() { + let d = UNIX_EPOCH; + assert_eq!(fmt_http_date(d), "Thu, 01 Jan 1970 00:00:00 GMT"); + let d = UNIX_EPOCH + Duration::from_secs(1475419451); + assert_eq!(fmt_http_date(d), "Sun, 02 Oct 2016 14:44:11 GMT"); + } + + #[test] + fn size_of() { + assert_eq!(::std::mem::size_of::(), 8); + } +} diff --git a/src/utils.rs b/src/utils/mod.rs similarity index 78% rename from src/utils.rs rename to src/utils/mod.rs index dce419c..9ab46aa 100644 --- a/src/utils.rs +++ b/src/utils/mod.rs @@ -1,3 +1,7 @@ +mod date; + +pub(crate) use date::{fmt_http_date, parse_http_date}; + /// Declares unstable items. #[doc(hidden)] macro_rules! cfg_unstable {