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improve webhook parsing

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This commit is contained in:
qpismont
2026-06-01 21:10:45 +00:00
parent 7e3b49ad76
commit 0a22be252c
6 changed files with 193 additions and 284 deletions
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src/api.rs
+60 -84
View File
@@ -1,34 +1,28 @@
use std::fmt::Debug;
use anyhow::anyhow;
use axum::body::to_bytes;
use axum::extract::{FromRef, FromRequest, FromRequestParts, State};
use axum::body::{Bytes, to_bytes};
use axum::extract::{FromRef, FromRequest};
use axum::response::{IntoResponse, Response};
use axum::routing::{get, post};
use axum::{Json, RequestExt, Router};
use axum::{Json, Router};
use hmac::{Hmac, KeyInit, Mac};
use serde_json::Value;
use sha2::Sha256;
use subtle::ConstantTimeEq;
use crate::consts::{GITEA_EVENT_TYPE_HEADER_NAME, GITEA_SIG_HEADER_NAME, MAX_WEBHOOK_BODY_SIZE};
use crate::errors::AppError;
use crate::gitea::WebhookType;
use crate::state::AppState;
const MAX_WEBHOOK_BODY_SIZE: usize = 1024 * 1024; // 1 Mo
pub async fn start(app_state: AppState) -> anyhow::Result<()> {
let http_port = app_state.config.http_port;
let app = Router::new()
.route("/", get(root))
.route("/webhook", post(webhook))
.with_state(app_state);
let listerner = tokio::net::TcpListener::bind(format!("0.0.0.0:{}", http_port)).await?;
axum::serve(listerner, app)
let listener = tokio::net::TcpListener::bind(format!("0.0.0.0:{}", http_port)).await?;
axum::serve(listener, app)
.await
.map_err(|e| anyhow::anyhow!(e))
.map_err(anyhow::Error::from)
}
async fn root() -> &'static str {
@@ -36,11 +30,7 @@ async fn root() -> &'static str {
}
async fn webhook(WebhookExtract(wb): WebhookExtract) -> Result<Response, AppError> {
Ok(match wb {
WebhookType::Review(id, _) => format!("Received {} pr id", id),
_ => String::from("Nothing to see :/"),
}
.into_response())
Ok("lol".into_response())
}
pub struct WebhookExtract(pub WebhookType);
@@ -52,84 +42,70 @@ where
{
type Rejection = AppError;
async fn from_request(
mut req: axum::extract::Request,
state: &S,
) -> Result<Self, Self::Rejection> {
let State(state) = req
.extract_parts_with_state::<State<AppState>, _>(state)
.await
.unwrap();
let secret_key = state.config.webhook_secret.as_bytes();
async fn from_request(req: axum::extract::Request, state: &S) -> Result<Self, Self::Rejection> {
let app_state = AppState::from_ref(state);
let headers = req.headers();
let sig_header = headers
.get("x-gitea-signature")
.ok_or(AppError::WebHookSigHeaderNotFoundErr)?
.to_str()
.map_err(|err| anyhow!(err))?
.to_string();
let body = req.into_body();
let body_bytes = to_bytes(body, MAX_WEBHOOK_BODY_SIZE)
.await
.map_err(|err| anyhow!(err))?;
let sig_header = extract_header(GITEA_SIG_HEADER_NAME, headers)?;
let type_header = extract_header(GITEA_EVENT_TYPE_HEADER_NAME, headers)?;
let body_bytes = read_body(req.into_body()).await?;
check_sig_header(secret_key, sig_header.as_bytes(), &body_bytes)?;
verify_signature(
app_state.config.webhook_secret.as_bytes(),
&sig_header,
&body_bytes,
)?;
let Json(value) =
Json::<Value>::from_bytes(&body_bytes).map_err(|_| AppError::MalformedJsonErr)?;
let webhook = WebhookType::try_from(value)?;
let webhook = parse_webhook(&type_header, &body_bytes)?;
reject_bot_user(&app_state, &webhook)?;
Ok(WebhookExtract(webhook))
}
}
fn check_sig_header(secret_key: &[u8], sig_header: &[u8], body: &[u8]) -> Result<(), AppError> {
let sig_header_decoded = hex::decode(sig_header).map_err(|_| AppError::WebHookSigHeaderInvalidErr)?;
fn extract_header(key: &str, headers: &axum::http::HeaderMap) -> Result<String, AppError> {
let value = headers
.get(key)
.ok_or(AppError::WebHookMissingHeaderErr(key.into()))?
.to_str()
.map_err(anyhow::Error::from)?;
Ok(value.to_owned())
}
let mut mac = Hmac::<Sha256>::new_from_slice(secret_key).map_err(|err| anyhow!(err))?;
async fn read_body(body: axum::body::Body) -> Result<Bytes, AppError> {
to_bytes(body, MAX_WEBHOOK_BODY_SIZE)
.await
.map_err(anyhow::Error::from)
.map_err(AppError::from)
}
fn parse_webhook(header: &str, body_bytes: &[u8]) -> Result<WebhookType, AppError> {
let Json(value) =
Json::<Value>::from_bytes(body_bytes).map_err(|_| AppError::MalformedJsonErr)?;
WebhookType::from_event(header, value)
}
fn reject_bot_user(state: &AppState, webhook: &WebhookType) -> Result<(), AppError> {
let user_id = match webhook {
WebhookType::Review(review_payload) => review_payload.comment.user.id,
};
match user_id != state.config.bot_user_id {
true => Ok(()),
false => Err(AppError::UnauthorizedUserIdErr),
}
}
fn verify_signature(secret_key: &[u8], sig_header: &str, body: &[u8]) -> Result<(), AppError> {
let sig_header_decoded =
hex::decode(sig_header).map_err(|_| AppError::WebHookSigHeaderInvalidErr)?;
let mut mac = Hmac::<Sha256>::new_from_slice(secret_key).map_err(anyhow::Error::from)?;
mac.update(body);
let generated_hmac = mac.finalize().into_bytes();
let check_result: bool = generated_hmac.ct_eq(&sig_header_decoded).into();
match check_result {
true => Ok(()),
false => Err(AppError::WebHookSigHeaderInvalidErr),
}
}
#[cfg(test)]
mod tests {
use super::*;
use serde_json::json;
#[test]
fn valid_json_bytes_parse_to_value() {
let body = serde_json::to_vec(
&json!({"action": "created", "pull_request": {"id": 1}, "comment": {"body": "hi"}}),
)
.unwrap();
let Json(value) = Json::<Value>::from_bytes(&body).unwrap();
assert_eq!(value["action"], "created");
assert_eq!(value["pull_request"]["id"], 1);
assert_eq!(value["comment"]["body"], "hi");
}
#[test]
fn malformed_json_bytes_return_malformed_error() {
let body = b"not valid json";
let result = Json::<Value>::from_bytes(body);
assert!(result.is_err());
}
#[test]
fn empty_body_returns_malformed_error() {
let body = b"";
let result = Json::<Value>::from_bytes(body);
assert!(result.is_err());
}
bool::from(generated_hmac.ct_eq(&sig_header_decoded))
.then_some(())
.ok_or(AppError::WebHookSigHeaderInvalidErr)
}
src/consts.rs
+3
View File
@@ -0,0 +1,3 @@
pub const GITEA_SIG_HEADER_NAME: &str = "x-gitea-signature";
pub const GITEA_EVENT_TYPE_HEADER_NAME: &str = "x-gitea-event-type";
pub const MAX_WEBHOOK_BODY_SIZE: usize = 1024 * 1024; // 1 MiB
src/env.rs
+4 -4
View File
@@ -6,21 +6,21 @@ pub struct EnvConfig {
pub http_port: u16,
pub webhook_secret: String,
pub open_router_api_key: String,
pub bot_name: String,
pub bot_user_id: u64,
}
pub fn load_config() -> anyhow::Result<EnvConfig> {
dotenv().ok();
let http_port = try_get_env("HTTP_PORT")?.parse()?;
let bot_name = try_get_env("BOT_NAME")?;
let bot_user_id = try_get_env("BOT_USER_ID")?.parse()?;
let webhook_secret = try_get_env("WEBHOOK_SIG_HEADER_SECRET")?;
let open_router_api_key = try_get_env("OPEN_ROUTER_API_KEY")?;
Ok(EnvConfig {
http_port,
webhook_secret,
bot_name,
bot_user_id,
open_router_api_key,
})
}
@@ -28,7 +28,7 @@ pub fn load_config() -> anyhow::Result<EnvConfig> {
fn try_get_env(key: &str) -> anyhow::Result<String> {
let env = std::env::var(key)?;
if env.trim().len() == 0 {
if env.trim().is_empty() {
return Err(anyhow!(format!("env var {} is empty", env)));
}
src/errors.rs
+25 -35
View File
@@ -3,24 +3,24 @@ use reqwest::StatusCode;
#[derive(thiserror::Error, Debug)]
pub enum AppError {
#[error("Unauthorized user id")]
UnauthorizedUserIdErr,
#[error("Unknow gitea event")]
UnknownEventErr,
#[error("Malformed Json")]
MalformedJsonErr,
#[error("Json not contains mandatory fields")]
BadJsonStructErr,
#[error(transparent)]
BadJsonStructErr(#[from] serde_json::Error),
#[error("WebHook sig header not found")]
WebHookSigHeaderNotFoundErr,
#[error("WebHook header not found")]
WebHookMissingHeaderErr(String),
#[error("WebHook sig header is invalid")]
WebHookSigHeaderInvalidErr,
#[error("Missing required field: {0}")]
MissingField(String),
#[error("Wrong type for field: {0}")]
WrongFieldType(String),
#[error(transparent)]
Other(#[from] anyhow::Error),
}
@@ -28,39 +28,29 @@ pub enum AppError {
impl IntoResponse for AppError {
fn into_response(self) -> axum::response::Response {
match self {
AppError::MalformedJsonErr => {
(StatusCode::BAD_REQUEST, "Malformed Json".to_string()).into_response()
AppError::UnknownEventErr => {
(StatusCode::BAD_REQUEST, "Unknow gitea event".to_string())
}
AppError::BadJsonStructErr => (
AppError::UnauthorizedUserIdErr => {
(StatusCode::BAD_REQUEST, "Unauthorized user id".to_string())
}
AppError::MalformedJsonErr => (StatusCode::BAD_REQUEST, "Malformed Json".to_string()),
AppError::BadJsonStructErr(err) => (
StatusCode::BAD_REQUEST,
"Json not contains mandatory fields".to_string(),
)
.into_response(),
AppError::WebHookSigHeaderNotFoundErr => (
StatusCode::BAD_REQUEST,
"WebHook sig header not found".to_string(),
)
.into_response(),
format!("Json not contains mandatory fields: {}", err),
),
AppError::WebHookMissingHeaderErr(h) => {
(StatusCode::BAD_REQUEST, format!("header {} is missing", h))
}
AppError::WebHookSigHeaderInvalidErr => (
StatusCode::UNAUTHORIZED,
"WebHook sig header is invalid".to_string(),
)
.into_response(),
AppError::MissingField(ref field) => (
StatusCode::BAD_REQUEST,
format!("Missing required field: {}", field),
)
.into_response(),
AppError::WrongFieldType(ref field) => (
StatusCode::BAD_REQUEST,
format!("Wrong type for field: {}", field),
)
.into_response(),
),
AppError::Other(_) => (
StatusCode::INTERNAL_SERVER_ERROR,
"Internal server error".to_string(),
)
.into_response(),
),
}
.into_response()
}
}
src/gitea.rs
+100 -161
View File
@@ -1,46 +1,43 @@
use serde::Deserialize;
use serde_json::Value;
use crate::errors::AppError;
#[derive(Debug, PartialEq)]
#[derive(Debug)]
pub enum WebhookType {
Review(u64, String),
Review(ReviewPayload),
}
impl TryFrom<Value> for WebhookType {
type Error = AppError;
#[derive(Deserialize, Debug)]
pub struct ReviewPayload {
pub action: String,
pub pull_request: PullRequest,
pub comment: Comment,
}
fn try_from(json: Value) -> Result<Self, Self::Error> {
let pull_request = json.get("pull_request");
let comment = json.get("comment");
let action = json
.get("action")
.ok_or(AppError::MissingField("action".into()))?
.as_str()
.ok_or(AppError::WrongFieldType("action".into()))?;
#[derive(Deserialize, Debug)]
pub struct PullRequest {
pub id: u64,
}
if action != "created" {
return Err(AppError::BadJsonStructErr);
#[derive(Deserialize, Debug)]
pub struct Comment {
pub id: u64,
pub body: String,
pub user: User,
}
#[derive(Deserialize, Debug)]
pub struct User {
pub id: u64,
}
impl WebhookType {
pub fn from_event(event: &str, json: Value) -> Result<Self, AppError> {
match event {
"pull_request_comment" => Ok(WebhookType::Review(serde_json::from_value(json)?)),
_ => Err(AppError::UnknownEventErr),
}
if let (Some(pull_request), Some(comment)) = (pull_request, comment) {
let comment_body = comment
.get("body")
.ok_or(AppError::MissingField("comment.body".into()))?
.as_str()
.ok_or(AppError::WrongFieldType("comment.body".into()))?
.to_string();
let pr_id = pull_request
.get("id")
.ok_or(AppError::MissingField("pull_request.id".into()))?
.as_u64()
.ok_or(AppError::WrongFieldType("pull_request.id".into()))?;
return Ok(WebhookType::Review(pr_id, comment_body));
}
Err(AppError::BadJsonStructErr)
}
}
@@ -50,149 +47,91 @@ mod tests {
use serde_json::json;
#[test]
fn valid_webhook_parses_review() {
let payload = json!({
fn test_from_event_valid_pull_request_comment() {
let json = json!({
"action": "created",
"pull_request": { "id": 42 },
"comment": { "body": "LGTM" }
"pull_request": {
"id": 42
},
"comment": {
"id": 7,
"body": "LGTM",
"user": {
"id": 100
}
}
});
let result = WebhookType::try_from(payload).unwrap();
assert_eq!(result, WebhookType::Review(42, "LGTM".into()));
let result = WebhookType::from_event("pull_request_comment", json);
assert!(result.is_ok());
match result.unwrap() {
WebhookType::Review(payload) => {
assert_eq!(payload.action, "created");
assert_eq!(payload.pull_request.id, 42);
assert_eq!(payload.comment.id, 7);
assert_eq!(payload.comment.body, "LGTM");
assert_eq!(payload.comment.user.id, 100);
}
}
}
#[test]
fn missing_action_returns_error() {
let payload = json!({
"pull_request": { "id": 1 },
"comment": { "body": "ok" }
});
let err = WebhookType::try_from(payload).unwrap_err();
assert!(matches!(err, AppError::MissingField(ref f) if f == "action"));
fn test_from_event_unknown_event() {
let json = json!({});
let result = WebhookType::from_event("push", json);
assert!(result.is_err());
match result.unwrap_err() {
AppError::UnknownEventErr => {}
_ => panic!("expected UnknownEventErr"),
}
}
#[test]
fn action_not_created_returns_bad_json_struct() {
let payload = json!({
"action": "updated",
"pull_request": { "id": 1 },
"comment": { "body": "ok" }
fn test_from_event_malformed_json() {
let json = json!({
"action": "created"
// pull_request and comment are missing
});
let err = WebhookType::try_from(payload).unwrap_err();
assert!(matches!(err, AppError::BadJsonStructErr));
let result = WebhookType::from_event("pull_request_comment", json);
assert!(result.is_err());
match result.unwrap_err() {
AppError::BadJsonStructErr(_) => {}
_ => panic!("expected BadJsonStructErr"),
}
}
#[test]
fn action_not_a_string_returns_error() {
let payload = json!({
"action": 123,
"pull_request": { "id": 1 },
"comment": { "body": "ok" }
fn test_deserialize_review_payload() {
let json = json!({
"action": "edited",
"pull_request": {
"id": 99
},
"comment": {
"id": 12,
"body": "Needs work",
"user": {
"id": 200
}
}
});
let err = WebhookType::try_from(payload).unwrap_err();
assert!(matches!(err, AppError::WrongFieldType(ref f) if f == "action"));
let payload: ReviewPayload = serde_json::from_value(json).unwrap();
assert_eq!(payload.action, "edited");
assert_eq!(payload.pull_request.id, 99);
assert_eq!(payload.comment.id, 12);
assert_eq!(payload.comment.body, "Needs work");
assert_eq!(payload.comment.user.id, 200);
}
#[test]
fn missing_pull_request_returns_bad_json_struct() {
let payload = json!({
"action": "created",
"comment": { "body": "ok" }
});
let err = WebhookType::try_from(payload).unwrap_err();
assert!(matches!(err, AppError::BadJsonStructErr));
}
#[test]
fn missing_comment_returns_bad_json_struct() {
let payload = json!({
"action": "created",
"pull_request": { "id": 1 }
});
let err = WebhookType::try_from(payload).unwrap_err();
assert!(matches!(err, AppError::BadJsonStructErr));
}
#[test]
fn missing_pr_id_returns_error() {
let payload = json!({
"action": "created",
"pull_request": { "number": 1 },
"comment": { "body": "ok" }
});
let err = WebhookType::try_from(payload).unwrap_err();
assert!(matches!(err, AppError::MissingField(ref f) if f == "pull_request.id"));
}
#[test]
fn pr_id_not_a_number_returns_error() {
let payload = json!({
"action": "created",
"pull_request": { "id": "not-a-number" },
"comment": { "body": "ok" }
});
let err = WebhookType::try_from(payload).unwrap_err();
assert!(matches!(err, AppError::WrongFieldType(ref f) if f == "pull_request.id"));
}
#[test]
fn missing_comment_body_returns_error() {
let payload = json!({
"action": "created",
"pull_request": { "id": 1 },
"comment": { "text": "no body" }
});
let err = WebhookType::try_from(payload).unwrap_err();
assert!(matches!(err, AppError::MissingField(ref f) if f == "comment.body"));
}
#[test]
fn comment_body_not_a_string_returns_error() {
let payload = json!({
"action": "created",
"pull_request": { "id": 1 },
"comment": { "body": 999 }
});
let err = WebhookType::try_from(payload).unwrap_err();
assert!(matches!(err, AppError::WrongFieldType(ref f) if f == "comment.body"));
}
#[test]
fn null_pull_request_returns_error() {
let payload = json!({
"action": "created",
"pull_request": null,
"comment": { "body": "ok" }
});
let err = WebhookType::try_from(payload).unwrap_err();
assert!(matches!(err, AppError::MissingField(ref f) if f == "pull_request.id"));
}
#[test]
fn null_comment_returns_error() {
let payload = json!({
"action": "created",
"pull_request": { "id": 1 },
"comment": null
});
let err = WebhookType::try_from(payload).unwrap_err();
assert!(matches!(err, AppError::MissingField(ref f) if f == "comment.body"));
}
#[test]
fn large_pr_id_parses_correctly() {
let payload = json!({
"action": "created",
"pull_request": { "id": 18446744073709551615u64 },
"comment": { "body": "max u64" }
});
let result = WebhookType::try_from(payload).unwrap();
assert_eq!(result, WebhookType::Review(18446744073709551615, "max u64".into()));
}
#[test]
fn full_webhook_payload_parses() {
let payload: Value = serde_json::from_str(include_str!("../docs/webhook_pr_body.json")).unwrap();
let result = WebhookType::try_from(payload).unwrap();
assert_eq!(result, WebhookType::Review(1, "Test comment".into()));
fn test_from_event_empty_json() {
let result = WebhookType::from_event("pull_request_comment", json!({}));
assert!(result.is_err());
assert!(matches!(result.unwrap_err(), AppError::BadJsonStructErr(_)));
}
}
src/main.rs
+1
View File
@@ -6,6 +6,7 @@ use crate::{bot::Bot, state::AppState};
mod api;
mod bot;
mod consts;
mod env;
mod errors;
mod gitea;