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use clap::Parser;
use oauth2::basic::BasicErrorResponseType;
use oauth2::http::Response;
use oauth2::url::Url;
use oauth2::{
basic::BasicTokenType, reqwest, AccessToken, AuthUrl, ClientId,
ClientSecret, IntrospectionUrl, StandardErrorResponse,
StandardRevocableToken, StandardTokenIntrospectionResponse,
StandardTokenResponse, TokenIntrospectionResponse,
};
use std::collections::HashSet;
use std::io::Write;
use std::process::Command;
use std::{env, io, process};
#[cfg(feature = "indieauth")]
mod indieauth;
mod error;
use error::Error;
/// A CGI wrapper to validate OAuth2 bearer tokens before executing another
/// script.
#[derive(Parser, Debug)]
struct Args {
/// The OAuth2 client id to authenticate with the introspection endpoint.
/// This may also be provided through the OAUTH2_CLIENT_ID environment
/// variable.
#[arg(long = "client-id")]
client_id: Option<String>,
/// The OAuth2 client secret.
/// This may also be provided through the OAUTH2_CLIENT_SECRET environment
/// variable.
#[arg(long = "secret")]
client_secret: Option<String>,
/// Scopes that must be present for the request to succeed.
#[arg(long = "scope")]
scope: Vec<String>,
/// The URL of the Authorization endpoint.
auth_url: Url,
/// The URL of the token introspection endpoint.
introspection_url: Url,
/// The command to run if authorized.
command: String,
/// Arguments to pass to the command.
args: Vec<String>,
}
const BEARER_TOKEN_PREFIX: &str = "Bearer ";
#[cfg(feature = "indieauth")]
type TokenType = indieauth::IndieAuthToken;
#[cfg(not(feature = "indieauth"))]
type TokenType = oauth2::EmptyExtraTokenFields;
type Client = oauth2::Client<
StandardErrorResponse<BasicErrorResponseType>,
StandardTokenResponse<TokenType, BasicTokenType>,
BasicTokenType,
StandardTokenIntrospectionResponse<TokenType, BasicTokenType>,
StandardRevocableToken,
StandardErrorResponse<BasicErrorResponseType>,
>;
fn handle_request() -> Result<Response<Option<String>>, Error> {
let args = Args::parse();
let client_id = args
.client_id
.or_else(|| env::var("OAUTH2_CLIENT_ID").ok())
.map(ClientId::new)
.expect("Missing required argument --client-id");
let client_secret = args
.client_secret
.or_else(|| env::var("OAUTH2_CLIENT_SECRET").ok())
.map(ClientSecret::new);
let client = Client::new(
client_id,
client_secret,
AuthUrl::from_url(args.auth_url),
None,
)
.set_introspection_uri(IntrospectionUrl::from_url(args.introspection_url));
let access_token = env::var("HTTP_AUTHORIZATION")
.ok()
.filter(|value| value.starts_with(BEARER_TOKEN_PREFIX))
.map(|value| {
AccessToken::new(
value.split_at(BEARER_TOKEN_PREFIX.len()).1.to_string(),
)
})
.ok_or_else(|| {
log::info!("Authorization failed due to missing or malformed Authorization header");
Error::MissingToken
})?;
let resp = client
.introspect(&access_token)
.map_err(|e| {
log::error!("OAuth2 client configuration error: {}", e);
Error::ConfigurationError
})?
.request(reqwest::http_client)
.map_err(|e| {
log::warn!("Error from token introspection service: {:?}", e);
Error::IntrospectionServerError
})
.and_then(|resp| {
if resp.active() {
Ok(resp)
} else {
log::info!("Authorization failed due to invalid token");
Err(Error::InvalidToken)
}
})?;
let authorized_scopes: HashSet<&str> = resp
.scopes()
.iter()
.flat_map(|s| s.iter())
.map(|s| s.as_ref())
.collect();
// Check if all required scopes are granted by the token.
if !args
.scope
.iter()
.all(|s| authorized_scopes.contains(s.as_str()))
{
log::info!("Authorization failed due to missing required scope(s)");
return Err(Error::AccessDenied);
}
let scopes = authorized_scopes.iter().fold(String::new(), |mut a, b| {
a.push_str(b);
a.push(' ');
a
});
let mut cmd = Command::new(args.command);
cmd.args(args.args);
cmd.env("OAUTH2_SCOPES", scopes.trim_end());
#[cfg(feature = "indieauth")]
cmd.env("INDIEAUTH_ME", resp.extra_fields().me());
let status = cmd.status()?.code().unwrap_or(0);
process::exit(status)
}
fn main() {
env_logger::init();
let resp = handle_request().unwrap_or_else(|e| e.into());
println!(
"Status: {} {}",
resp.status().as_str(),
resp.status().canonical_reason().unwrap_or("")
);
for (name, value) in resp.headers().iter() {
print!("{}: ", name);
io::stdout().write_all(value.as_bytes()).expect("IO Error");
println!();
}
if let Some(body) = resp.body() {
println!("Content-Type: application/json");
println!();
println!("{}", body)
} else {
println!();
}
}
|
