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#![allow(clippy::needless_doctest_main, clippy::must_use_candidate)]
//! `alog` is a simple log file anonymizer.
//!
//! ## About
//!
//! In fact by default `alog` just replaces the first *word* on every line of any input stream
//! with a customizable string.
//!
//! With version 0.6 you can (at a substantial cost of CPU cycles) replace the `$remote_user`
//! with `"-"` ([`Config::authuser`] set to `true`) as well. Defaults to `false`.
//!
//! With [`Config::trim`] set to `false` the first *word* can be the (zero width)
//! anchor ^ or a single `b' '` (Space) separated by a `b' '` from the remainder of the line.
//! This was the default behaviour prior to version 0.6.
//!
//! So "log file anonymizer" might be a bit of an overstatement, but `alog` can be used to (very
//! efficiently) replace the `$remote_addr` part in many access log formats, e.g. Nginx' default
//! combined log format:
//!
//! ```text
//! log_format combined '$remote_addr - $remote_user [$time_local] '
//! '"$request" $status $body_bytes_sent '
//! '"$http_referer" "$http_user_agent"';
//! ```
//!
//! By default any parseable `$remote_addr` is replaced by it's *localhost* representation,
//!
//! * any valid IPv4 address is replaced by `127.0.0.1`,
//! * any valid IPv6 address is replaced by `::1` and
//! * any String (what might be a domain name) with `localhost`.
//!
//! Lines without a 'first word' will remain unchanged (but can be skipped with [`Config::skip`]
//! set to `true`).
//!
//! Starting with version 0.6 all Space and Tabulator (`b'\t'`) and from version 0.7 on all
//! [ASCII whitespace](https://infra.spec.whatwg.org/#ascii-whitespace) characters will be removed
//! from the beginning of each line before replacing any `$remote_addr` by default.
//! To switch back to the previous behaviour just set [`Config::trim`] to `false`.
//!
//! ### Personal data in server logs
//!
//! The default configuration of popular web servers including Apache Web Server and Nginx collect
//! and store at least two of the following three types of logs:
//!
//! 1. access logs
//! 2. error logs (including processing-language logs like PHP)
//! 3. security audit logs
//!
//! All of these logs contain personal information by default. IP addresses are specifically
//! defined as personal data by the [GDPR]. The logs can also contain usernames if your web
//! service uses them as part of their URL structure, and even the referral information that’s
//! logged by default **can** contain personal information (or other sensitive data).
//!
//! So keep in mind, just removing the IP / `$remote_addr` or `$remote_user` part might not be
//! enough to fully anonymize any given log file.
//!
//! [GDPR]: https://gdpr.eu/article-4-definitions/
use std::cmp::Ordering;
use std::fs::{File, OpenOptions};
use std::io::{self, BufRead, BufReader, BufWriter, Write};
use std::path::Path;
use std::{fmt, net};
use regex::bytes::Regex;
#[macro_use(lazy_static)]
extern crate lazy_static;
lazy_static! {
// $remote_user *can* contain whitespaces, so we search for the 'next'
// field (`$time_local`) instead
static ref RE: Regex = Regex::new(" \\[[0-9]{1,2}/").unwrap();
}
#[derive(Debug)]
pub struct IOError {
message: String,
}
impl fmt::Display for IOError {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "{}", self.message)
}
}
impl From<io::Error> for IOError {
fn from(error: io::Error) -> Self {
IOError {
message: error.to_string(),
}
}
}
/// INPUT / OUTPUT config
#[derive(Debug)]
pub struct IOConfig<'a> {
/// List of input paths / files, e.g. `Some(vec![Path::new("/tmp/test1.log"), Path::new("/tmp/test2.log")])`
/// If set to `None` the reader will read from Stdin.
input: Option<Vec<&'a Path>>,
/// Single output path / file
/// If set to `None` the writer will write to Stdout.
output: Option<&'a Path>,
}
/// Collection of replacement strings / config flags
#[allow(clippy::struct_excessive_bools)]
#[derive(Debug)]
pub struct Config<'a> {
/// IPv4-parseable `$remote_addr` replacement string
pub ipv4: &'a str,
/// IPv6-parseable `$remote_addr` replacement string
pub ipv6: &'a str,
/// `$remote_addr` replacement string
pub host: &'a str,
/// Skip lines w/o a `$remote_addr` part / first word
pub skip: bool,
/// Try to clear the authuser field
pub authuser: bool,
/// Trim spaces from the start of every line
pub trim: bool,
/// Don't clear authuser fields starting with "- ["
/// We assume these fields are already cleared.
pub optimize: bool,
/// Flush output after each line
pub flush: bool,
}
/// defaults to `None` for both input and output
impl<'a> Default for IOConfig<'a> {
fn default() -> Self {
IOConfig {
input: None,
output: None,
}
}
}
/// `$remote_addr` replacements default to an equivalent of *localhost*
impl<'a> Default for Config<'a> {
fn default() -> Self {
Config {
ipv4: "127.0.0.1",
ipv6: "::1",
host: "localhost",
skip: false,
authuser: false,
trim: true,
optimize: true,
flush: false,
}
}
}
impl<'a> Config<'a> {
pub fn new() -> Self {
Self::default()
}
/// Get IPv4 replacement value
pub fn get_ipv4_value(&self) -> &'a str {
self.ipv4
}
/// Get IPv6 replacement value
pub fn get_ipv6_value(&self) -> &'a str {
self.ipv6
}
/// Get string replacement value
pub fn get_host_value(&self) -> &'a str {
self.host
}
/// Get `skip` value
pub fn get_skip(&self) -> bool {
self.skip
}
/// Get `authuser` value
pub fn get_authuser(&self) -> bool {
self.authuser
}
/// Get `trim` value
pub fn get_trim(&self) -> bool {
self.trim
}
/// Get `optimize` value
pub fn get_optimize(&self) -> bool {
self.optimize
}
/// Get `flush` value
pub fn get_flush(&self) -> bool {
self.flush
}
/// Set IPv4 replacement `String`
pub fn set_ipv4_value(&mut self, ipv4: &'a str) {
self.ipv4 = ipv4;
}
/// Set IPv6 replacement `String`
pub fn set_ipv6_value(&mut self, ipv6: &'a str) {
self.ipv6 = ipv6;
}
/// Set `hostname` replacement `String`
pub fn set_host_value(&mut self, host: &'a str) {
self.host = host;
}
/// Set `flush` field
pub fn set_flush(&mut self, b: bool) {
self.flush = b;
}
/// Set `authuser` field
pub fn set_authuser(&mut self, b: bool) {
self.authuser = b;
}
/// Set `trim` field
pub fn set_trim(&mut self, b: bool) {
self.trim = b;
}
/// Set `optimize` field
pub fn set_optimize(&mut self, b: bool) {
self.optimize = b;
}
/// Set `skip` field
pub fn set_skip(&mut self, b: bool) {
self.skip = b;
}
}
impl<'a> IOConfig<'a> {
pub fn new() -> Self {
Self::default()
}
/// Get input / reader names, if any (defaults to `None`)
pub fn get_input(&self) -> Option<&Vec<&'a Path>> {
self.input.as_ref()
}
/// Get output / writer name (defaults to `None`)
pub fn get_output(&self) -> Option<&'a Path> {
self.output
}
/// Add input `Path`
pub fn push_input<P: AsRef<Path> + ?Sized>(&mut self, i: &'a P) {
if let Some(input) = &mut self.input {
input.push(i.as_ref());
} else {
self.input = Some(vec![]);
self.push_input(i);
}
}
/// Set output `Path`
pub fn set_output(&mut self, o: &'a Path) {
self.output = Some(o);
}
}
/// Reads lines from `reader`, if there is a '*first word*' (any String separated from the
/// remainder of the line by a b' ' (Space) byte) this word will be replaced
///
/// Any word, that can be parsed as
/// * [`std::net::Ipv4Addr`] will be replaced with [`alog::Config::ipv4`],
/// * [`std::net::Ipv6Addr`] will be replaced with [`alog::Config::ipv6`],
/// * any other *word* will be replaced with [`alog::Config::host`].
///
/// Any line without a 'first word' will be written as is if [`alog::Config::get_skip()`] returns
/// `false` (default), or will be skipped otherwise.
///
/// ## Errors
///
/// This function will return an I/O error if the underlying reader or writer returns an error.
///
/// [`alog::Config::get_ipv4_value()`]: ./struct.Config.html#method.get_ipv4_value
/// [`alog::Config::get_ipv6_value()`]: ./struct.Config.html#method.get_ipv6_value
/// [`alog::Config::get_host_value()`]: ./struct.Config.html#method.get_host_value
fn replace_remote_address<R: BufRead, W: Write>(
config: &Config,
mut reader: R,
mut writer: W,
) -> Result<(), io::Error> {
let mut buf = vec![];
'lines: loop {
buf.clear();
let bytes_read = reader.read_until(b'\n', &mut buf)?;
if bytes_read == 0 {
break;
}
// #[allow(clippy::match_wildcard_for_single_variants)]
if config.get_trim() {
let s = buf
.iter()
.position(|&x| !x.is_ascii_whitespace())
.unwrap_or(0);
buf.drain(..s);
}
for (i, byte) in buf[..].iter().enumerate() {
if *byte == b' ' {
if String::from_utf8_lossy(&buf[..i])
.parse::<net::Ipv4Addr>()
.is_ok()
{
write!(&mut writer, "{}", config.get_ipv4_value())?;
} else if String::from_utf8_lossy(&buf[..i])
.parse::<net::Ipv6Addr>()
.is_ok()
{
write!(&mut writer, "{}", config.get_ipv6_value())?;
} else {
write!(&mut writer, "{}", config.get_host_value())?;
}
if config.get_authuser() {
// trying to avoid the regex' overhead
if config.get_optimize() && buf.len() >= i + 6 {
if buf[i + 3..i + 6].iter().cmp(b"- [") == Ordering::Equal {
writer.write_all(&buf[i..])?;
} else if let Some(time_field) = RE.find_at(&buf, i) {
write!(&mut writer, " - -")?;
writer.write_all(&buf[time_field.start()..])?;
} else {
writer.write_all(&buf[i..])?;
}
} else if let Some(time_field) = RE.find_at(&buf, i) {
write!(&mut writer, " - -")?;
writer.write_all(&buf[time_field.start()..])?;
} else {
writer.write_all(&buf[i..])?;
}
} else {
writer.write_all(&buf[i..])?;
}
if config.get_flush() {
writer.flush()?;
}
continue 'lines;
}
}
if !config.get_skip() {
writer.write_all(&buf)?;
if config.get_flush() {
writer.flush()?;
}
}
}
writer.flush()?;
Ok(())
}
/// Creates a reader (defaults to [`std::io::Stdin`]) and writer (defaults to [`std::io::Stdout`])
/// from [`alog::IOConfig`] and uses both along with [`alog::Config`] to actually replace
/// any first *word* in `reader` with strings stored in [`alog::Config`].
///
/// Appends data if the writer points to an existing, writeable file.
///
/// ## Errors
///
/// Returns an error if the new reader / writer retruns an error.
///
/// ## Example
///
/// ```[no_run]
/// fn main() {
/// alog::run(
/// &alog::Config {
/// host: "XXX",
/// ..Default::default()
/// },
/// &alog::IOConfig::default()
/// ).unwrap();
/// }
/// ```
///
/// [`alog::Config`]: ./struct.Config.html
/// [`alog::IOConfig`]: ./struct.IOConfig.html
/// [`alog::IOConfig::get_output()`]: ./struct.IOConfig.html#method.get_output
/// [`std::io::Stdin`]: https://doc.rust-lang.org/std/io/struct.Stdin.html
/// [`std::io::Stdout`]: https://doc.rust-lang.org/std/io/struct.Stdout.html
/// [`std::net::Ipv4Addr`]: https://doc.rust-lang.org/std/net/struct.Ipv4Addr.html
/// [`std::net::Ipv6Addr`]: https://doc.rust-lang.org/std/net/struct.Ipv6Addr.html
pub fn run(config: &Config, ioconfig: &IOConfig) -> Result<(), IOError> {
// Set writer
let stdout = io::stdout();
let mut writer: Box<dyn Write> = match ioconfig.get_output() {
Some(output) => {
let f = match OpenOptions::new()
.create(true)
.append(true)
.open(Path::new(output))
{
Ok(f) => f,
Err(e) => {
return Err(IOError {
message: format!("Can not open output '{}': {e}", output.display()),
})
}
};
Box::new(BufWriter::new(f)) as _
}
None => Box::new(BufWriter::new(stdout.lock())),
};
// Set reader
if let Some(input) = ioconfig.get_input() {
for arg in input {
match File::open(Path::new(arg)) {
Err(e) => {
return Err(IOError {
message: format!("Can not open input '{}': {e}", arg.display()),
})
}
Ok(f) => {
let reader: Box<dyn BufRead> = Box::new(BufReader::new(f));
if let Err(e) = replace_remote_address(config, reader, &mut writer) {
return Err(IOError {
message: e.to_string(),
});
}
}
}
}
} else {
let stdin = io::stdin();
let reader: Box<dyn BufRead> = Box::new(stdin.lock());
if let Err(e) = replace_remote_address(config, reader, &mut writer) {
return Err(IOError {
message: e.to_string(),
});
}
}
Ok(())
}
/// Like [`alog::run`] but will let you pass your own `reader` and `writer`. Replacement strings
/// and config flags will still be read from [`alog::Config`].
///
/// ## Errors
///
/// Returns an error if the new reader or writer retruns an error.
///
/// ## Example
///
/// ```
/// use std::io::Cursor;
///
/// let line = Cursor::new(b"8.8.8.8 XxX");
/// let mut buffer = vec![];
///
/// alog::run_raw(&alog::Config::default(), line, &mut buffer).unwrap();
/// assert_eq!(buffer, b"127.0.0.1 XxX");
/// ```
///
/// To read from Stdin and write to Stdout:
///
/// ```no_run
/// use std::io::{self, BufReader, BufWriter};
///
/// // Consider wrapping io::stdout in BufWriter
/// let stdin = io::stdin();
/// let stdout = io::stdout();
/// alog::run_raw(&alog::Config::default(), stdin.lock(), stdout.lock()).unwrap();
/// ```
///
/// [`alog::run`]: ./fn.run.html
/// [`alog::Config`]: ./struct.Config.html
pub fn run_raw<R: BufRead, W: Write>(
config: &Config,
reader: R,
mut writer: W,
) -> Result<(), IOError> {
replace_remote_address(config, reader, &mut writer)?;
Ok(())
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn run_raw_function() {
use std::io::Cursor;
let line = Cursor::new(b"8.8.8.8 XxX");
let mut buffer = vec![];
run_raw(&Config::default(), line, &mut buffer).unwrap();
assert_eq!(buffer, b"127.0.0.1 XxX");
}
#[test]
fn replace_ipv4() {
use std::io::Cursor;
let mut buffer = Cursor::new(vec![]);
let log = Box::new("8.8.8.8 - frank [10/Oct/2000:13:55:36 -0700] \"GET /apache_pb.gif HTTP/1.0\" 200 2326 \"http://www.example.com/start.html\" \"Mozilla/4.08 [en] (Win98; I ;Nav)\"".as_bytes());
let local_log = "127.0.0.1 - frank [10/Oct/2000:13:55:36 -0700] \"GET /apache_pb.gif HTTP/1.0\" 200 2326 \"http://www.example.com/start.html\" \"Mozilla/4.08 [en] (Win98; I ;Nav)\"".as_bytes();
replace_remote_address(&Config::default(), log, &mut buffer).unwrap();
assert_eq!(&buffer.into_inner(), &local_log);
}
#[test]
fn replace_ipv6() {
use std::io::Cursor;
let mut buffer = Cursor::new(vec![]);
let log = Box::new("2a00:1450:4001:81b::2004 - frank [10/Oct/2000:13:55:36 -0700] \"GET /apache_pb.gif HTTP/1.0\" 200 2326 \"http://www.example.com/start.html\" \"Mozilla/4.08 [en] (Win98; I ;Nav)\"".as_bytes());
let local_log = "::1 - frank [10/Oct/2000:13:55:36 -0700] \"GET /apache_pb.gif HTTP/1.0\" 200 2326 \"http://www.example.com/start.html\" \"Mozilla/4.08 [en] (Win98; I ;Nav)\"".as_bytes();
replace_remote_address(&Config::default(), log, &mut buffer).unwrap();
assert_eq!(&buffer.into_inner(), &local_log);
}
#[test]
fn replace_host() {
use std::io::Cursor;
let mut buffer = Cursor::new(vec![]);
let log = Box::new("google.com - frank [10/Oct/2000:13:55:36 -0700] \"GET /apache_pb.gif HTTP/1.0\" 200 2326 \"http://www.example.com/start.html\" \"Mozilla/4.08 [en] (Win98; I ;Nav)\"".as_bytes());
let local_log = "localhost - frank [10/Oct/2000:13:55:36 -0700] \"GET /apache_pb.gif HTTP/1.0\" 200 2326 \"http://www.example.com/start.html\" \"Mozilla/4.08 [en] (Win98; I ;Nav)\"".as_bytes();
replace_remote_address(&Config::default(), log, &mut buffer).unwrap();
assert_eq!(&buffer.into_inner(), &local_log);
}
#[test]
fn clear_authuser() {
use std::io::Cursor;
let mut buffer = Cursor::new(vec![]);
let log = Box::new("8.8.8.8 - frank [10/Oct/2000:13:55:36 -0700] \"GET /apache_pb.gif HTTP/1.0\" 200 2326 \"http://www.example.com/start.html\" \"Mozilla/4.08 [en] (Win98; I ;Nav)\"".as_bytes());
let local_log = "127.0.0.1 - - [10/Oct/2000:13:55:36 -0700] \"GET /apache_pb.gif HTTP/1.0\" 200 2326 \"http://www.example.com/start.html\" \"Mozilla/4.08 [en] (Win98; I ;Nav)\"".as_bytes();
let mut conf = Config::default();
conf.set_authuser(true);
replace_remote_address(&conf, log, &mut buffer).unwrap();
assert_eq!(&buffer.into_inner(), &local_log);
}
#[test]
fn replace_custom_ipv4() {
use std::io::Cursor;
let mut buffer = Cursor::new(vec![]);
let log = Box::new("8.8.8.8 - frank [10/Oct/2000:13:55:36 -0700] \"GET /apache_pb.gif HTTP/1.0\" 200 2326 \"http://www.example.com/start.html\" \"Mozilla/4.08 [en] (Win98; I ;Nav)\"".as_bytes());
let local_log = "custom_ipv4 - frank [10/Oct/2000:13:55:36 -0700] \"GET /apache_pb.gif HTTP/1.0\" 200 2326 \"http://www.example.com/start.html\" \"Mozilla/4.08 [en] (Win98; I ;Nav)\"".as_bytes();
let mut conf = Config::default();
conf.set_ipv4_value("custom_ipv4");
replace_remote_address(&conf, log, &mut buffer).unwrap();
assert_eq!(&buffer.into_inner(), &local_log);
}
#[test]
fn replace_custom_ipv6() {
use std::io::Cursor;
let mut buffer = Cursor::new(vec![]);
let log = Box::new("2a00:1450:4001:81b::2004 - frank [10/Oct/2000:13:55:36 -0700] \"GET /apache_pb.gif HTTP/1.0\" 200 2326 \"http://www.example.com/start.html\" \"Mozilla/4.08 [en] (Win98; I ;Nav)\"".as_bytes());
let local_log = "custom_ipv6 - frank [10/Oct/2000:13:55:36 -0700] \"GET /apache_pb.gif HTTP/1.0\" 200 2326 \"http://www.example.com/start.html\" \"Mozilla/4.08 [en] (Win98; I ;Nav)\"".as_bytes();
let mut conf = Config::default();
conf.set_ipv6_value("custom_ipv6");
replace_remote_address(&conf, log, &mut buffer).unwrap();
assert_eq!(&buffer.into_inner(), &local_log);
}
#[test]
fn replace_custom_host() {
use std::io::Cursor;
let mut buffer = Cursor::new(vec![]);
let log = Box::new("google.com - frank [10/Oct/2000:13:55:36 -0700] \"GET /apache_pb.gif HTTP/1.0\" 200 2326 \"http://www.example.com/start.html\" \"Mozilla/4.08 [en] (Win98; I ;Nav)\"".as_bytes());
let local_log = "custom_host - frank [10/Oct/2000:13:55:36 -0700] \"GET /apache_pb.gif HTTP/1.0\" 200 2326 \"http://www.example.com/start.html\" \"Mozilla/4.08 [en] (Win98; I ;Nav)\"".as_bytes();
let mut conf = Config::default();
conf.set_host_value("custom_host");
replace_remote_address(&conf, log, &mut buffer).unwrap();
assert_eq!(&buffer.into_inner(), &local_log);
}
#[test]
fn notrim_and_auth() {
use std::io::Cursor;
let mut buffer = Cursor::new(vec![]);
let log = Box::new(" 8.8.8.8 - frank [10/Oct/2000:13:55:36 -0700] \"GET /apache_pb.gif HTTP/1.0\" 200 2326 \"http://www.example.com/start.html\" \"Mozilla/4.08 [en] (Win98; I ;Nav)\"".as_bytes());
let local_log = "localhost - - [10/Oct/2000:13:55:36 -0700] \"GET /apache_pb.gif HTTP/1.0\" 200 2326 \"http://www.example.com/start.html\" \"Mozilla/4.08 [en] (Win98; I ;Nav)\"".as_bytes();
let mut conf = Config::default();
conf.set_trim(false);
conf.set_authuser(true);
replace_remote_address(&conf, log, &mut buffer).unwrap();
assert_eq!(&buffer.into_inner(), &local_log);
}
}