#[derive(Debug, Clone, PartialEq, Eq)]
pub(crate) struct WebhookDelivery {
pub event: String,
}
pub(crate) fn parse_delivery(head: &str) -> Option<WebhookDelivery> {
let mut lines = head.lines();
let request_line = lines.next()?;
if !is_post_request(request_line) {
return None;
}
let event = lines
.take_while(|line| !line.is_empty())
.find_map(|line| {
let (name, value) = line.split_once(':')?;
name.trim()
.eq_ignore_ascii_case("x-github-event")
.then(|| value.trim().to_owned())
})
.unwrap_or_else(|| "unknown".to_owned());
Some(WebhookDelivery { event })
}
pub(crate) fn content_length(head: &str) -> Option<u64> {
let value = head
.lines()
.skip(1)
.take_while(|line| !line.is_empty())
.find_map(|line| {
let (name, value) = line.split_once(':')?;
name.trim()
.eq_ignore_ascii_case("content-length")
.then_some(value.trim())
})?;
value.parse().ok()
}
fn is_post_request(request_line: &str) -> bool {
let Some((method, target_and_version)) = request_line.split_once(' ') else {
return false;
};
let Some((target, version)) = target_and_version.split_once(' ') else {
return false;
};
method == "POST" && !target.is_empty() && matches!(version, "HTTP/1.0" | "HTTP/1.1")
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn request_line_contract_is_explicit() {
for (name, request_line, accepted) in [
("root", "POST / HTTP/1.1", true),
("http 1.0", "POST /hook HTTP/1.0", true),
("query", "POST /hook?id=42 HTTP/1.1", true),
("unicode target", "POST /déploiement HTTP/1.1", true),
("get", "GET / HTTP/1.1", false),
("put", "PUT / HTTP/1.1", false),
("patch", "PATCH / HTTP/1.1", false),
("lowercase", "post / HTTP/1.1", false),
("empty", "", false),
("method only", "POST", false),
("trailing separator", "POST ", false),
("missing version", "POST /", false),
("missing target", "POST HTTP/1.1", false),
("tab separators", "POST\t/\tHTTP/1.1", false),
("leading space", " POST / HTTP/1.1", false),
("http 2", "POST / HTTP/2", false),
("extra token", "POST / HTTP/1.1 extra", false),
("method prefix", "POSTER / HTTP/1.1", false),
] {
let actual = parse_delivery(request_line).is_some();
assert_eq!(actual, accepted, "{name}: {request_line:?}");
}
}
#[test]
fn event_header_contract_is_explicit() {
for (name, head, expected) in [
(
"canonical crlf",
"POST / HTTP/1.1\r\nX-GitHub-Event: pull_request\r\n",
"pull_request",
),
(
"lowercase lf",
"POST / HTTP/1.1\nx-github-event: check_run\n",
"check_run",
),
(
"uppercase",
"POST / HTTP/1.1\nX-GITHUB-EVENT: push\n",
"push",
),
(
"name whitespace",
"POST / HTTP/1.1\n X-GitHub-Event \t: issue_comment\n",
"issue_comment",
),
(
"value whitespace",
"POST / HTTP/1.1\nX-GitHub-Event:\t workflow_run \n",
"workflow_run",
),
("missing", "POST / HTTP/1.1\nHost: localhost\n", "unknown"),
("empty", "POST / HTTP/1.1\nX-GitHub-Event:\n", ""),
(
"whitespace only",
"POST / HTTP/1.1\nX-GitHub-Event: \t\n",
"",
),
(
"first duplicate",
"POST / HTTP/1.1\nX-GitHub-Event: push\nX-GitHub-Event: pull_request\n",
"push",
),
(
"empty first duplicate",
"POST / HTTP/1.1\nX-GitHub-Event:\nX-GitHub-Event: push\n",
"",
),
(
"malformed before valid",
"POST / HTTP/1.1\nnot a header\nX-GitHub-Event: release\n",
"release",
),
(
"missing colon",
"POST / HTTP/1.1\nX-GitHub-Event push\n",
"unknown",
),
(
"colon in value",
"POST / HTTP/1.1\nX-GitHub-Event: pull:request\n",
"pull:request",
),
(
"unicode value",
"POST / HTTP/1.1\nX-GitHub-Event: déploiement 🚀\n",
"déploiement 🚀",
),
(
"unicode header name",
"POST / HTTP/1.1\nX-GitHub-Évent: push\n",
"unknown",
),
(
"lf body separator",
"POST / HTTP/1.1\nHost: local\n\nX-GitHub-Event: push\n",
"unknown",
),
(
"crlf body separator",
"POST / HTTP/1.1\r\nHost: local\r\n\r\nX-GitHub-Event: push\r\n",
"unknown",
),
] {
let event = parse_delivery(head).map(|delivery| delivery.event);
assert_eq!(event.as_deref(), Some(expected), "{name}: {head:?}");
}
}
#[test]
fn content_length_contract_is_explicit() {
for (name, head, expected) in [
(
"canonical",
"POST / HTTP/1.1\nContent-Length: 12\n",
Some(12),
),
("lowercase", "POST / HTTP/1.1\ncontent-length: 7\n", Some(7)),
("uppercase", "POST / HTTP/1.1\nCONTENT-LENGTH: 8\n", Some(8)),
(
"whitespace",
"POST / HTTP/1.1\n Content-Length \t: 19 \t\n",
Some(19),
),
("zero", "POST / HTTP/1.1\nContent-Length: 0\n", Some(0)),
(
"leading zeroes",
"POST / HTTP/1.1\nContent-Length: 00012\n",
Some(12),
),
(
"maximum",
"POST / HTTP/1.1\nContent-Length: 18446744073709551615\n",
Some(u64::MAX),
),
(
"overflow",
"POST / HTTP/1.1\nContent-Length: 18446744073709551616\n",
None,
),
("negative", "POST / HTTP/1.1\nContent-Length: -1\n", None),
("decimal", "POST / HTTP/1.1\nContent-Length: 1.5\n", None),
("units", "POST / HTTP/1.1\nContent-Length: 12 bytes\n", None),
("empty", "POST / HTTP/1.1\nContent-Length:\n", None),
(
"whitespace only",
"POST / HTTP/1.1\nContent-Length: \t\n",
None,
),
("missing", "POST / HTTP/1.1\nHost: localhost\n", None),
(
"first duplicate",
"POST / HTTP/1.1\nContent-Length: 5\nContent-Length: 9\n",
Some(5),
),
(
"invalid first duplicate",
"POST / HTTP/1.1\nContent-Length: invalid\nContent-Length: 9\n",
None,
),
(
"malformed before valid",
"POST / HTTP/1.1\nnot a header\nContent-Length: 6\n",
Some(6),
),
(
"lf body confusion",
"POST / HTTP/1.1\nHost: local\n\nContent-Length: 99\n",
None,
),
(
"crlf body confusion",
"POST / HTTP/1.1\r\nHost: local\r\n\r\nContent-Length: 99\r\n",
None,
),
(
"real header before body",
"POST / HTTP/1.1\nContent-Length: 4\n\nContent-Length: 99\n",
Some(4),
),
(
"unicode digits",
"POST / HTTP/1.1\nContent-Length: １２\n",
None,
),
("hex", "POST / HTTP/1.1\nContent-Length: 0xc\n", None),
(
"internal whitespace",
"POST / HTTP/1.1\nContent-Length: 1 2\n",
None,
),
] {
assert_eq!(content_length(head), expected, "{name}: {head:?}");
}
}
}