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/*
* SPDX-FileCopyrightText: 2020 Stalwart Labs Ltd <hello@stalw.art>
*
* SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-SEL
*/
use common::listener::SessionStream;
use directory::Permission;
use imap_proto::{
protocol::{authenticate::Mechanism, capability::Capability},
receiver::{self, Request},
Command, ResponseCode, StatusResponse,
};
use mail_parser::decoders::base64::base64_decode;
use mail_send::Credentials;
use std::sync::Arc;
use crate::core::{Session, SessionData, State};
impl<T: SessionStream> Session<T> {
pub async fn handle_authenticate(&mut self, request: Request<Command>) -> trc::Result<()> {
let mut args = request.parse_authenticate()?;
match args.mechanism {
Mechanism::Plain | Mechanism::OAuthBearer => {
if !args.params.is_empty() {
let challenge = base64_decode(args.params.pop().unwrap().as_bytes())
.ok_or_else(|| {
trc::AuthEvent::Error
.into_err()
.details("Failed to decode challenge.")
.id(args.tag.clone())
.code(ResponseCode::Parse)
})?;
let credentials = if args.mechanism == Mechanism::Plain {
decode_challenge_plain(&challenge)
} else {
decode_challenge_oauth(&challenge)
}
.map_err(|err| {
trc::AuthEvent::Error
.into_err()
.details(err)
.id(args.tag.clone())
})?;
self.authenticate(credentials, args.tag).await
} else {
self.receiver.request = receiver::Request {
tag: args.tag,
command: Command::Authenticate,
tokens: vec![receiver::Token::Argument(args.mechanism.into_bytes())],
};
self.receiver.state = receiver::State::Argument { last_ch: b' ' };
self.write_bytes(b"+ \"\"\r\n".to_vec()).await
}
}
_ => Err(trc::AuthEvent::Error
.into_err()
.details("Authentication mechanism not supported.")
.id(args.tag)
.code(ResponseCode::Cannot)),
}
}
pub async fn authenticate(
&mut self,
credentials: Credentials<String>,
tag: String,
) -> trc::Result<()> {
// Throttle authentication requests
self.jmap
.is_auth_allowed_soft(&self.remote_addr)
.await
.map_err(|err| err.id(tag.clone()))?;
// Authenticate
let access_token = match credentials {
Credentials::Plain { username, secret } | Credentials::XOauth2 { username, secret } => {
self.jmap
.authenticate_plain(&username, &secret, self.remote_addr, self.session_id)
.await
}
Credentials::OAuthBearer { token } => {
match self
.jmap
.validate_access_token("access_token", &token)
.await
{
Ok((account_id, _, _)) => self.jmap.core.get_access_token(account_id).await,
Err(err) => Err(err),
}
}
}
.map_err(|err| {
if err.matches(trc::EventType::Auth(trc::AuthEvent::Failed)) {
let auth_failures = self.state.auth_failures();
if auth_failures < self.jmap.core.imap.max_auth_failures {
self.state = State::NotAuthenticated {
auth_failures: auth_failures + 1,
};
} else {
return trc::AuthEvent::TooManyAttempts.into_err().caused_by(err);
}
}
err.id(tag.clone())
})?;
// Enforce concurrency limits
let in_flight = match self
.get_concurrency_limiter(access_token.primary_id())
.map(|limiter| limiter.concurrent_requests.is_allowed())
{
Some(Some(limiter)) => Some(limiter),
None => None,
Some(None) => {
return Err(trc::LimitEvent::ConcurrentRequest
.into_err()
.id(tag.clone()));
}
};
// Validate access
access_token.assert_has_permission(Permission::ImapAuthenticate)?;
// Cache access token
let access_token = Arc::new(access_token);
self.jmap.core.cache_access_token(access_token.clone());
// Create session
self.state = State::Authenticated {
data: Arc::new(
SessionData::new(self, access_token, in_flight)
.await
.map_err(|err| err.id(tag.clone()))?,
),
};
self.write_bytes(
StatusResponse::ok("Authentication successful")
.with_code(ResponseCode::Capability {
capabilities: Capability::all_capabilities(
true,
!self.is_tls && self.instance.acceptor.is_tls(),
),
})
.with_tag(tag)
.into_bytes(),
)
.await
}
pub async fn handle_unauthenticate(&mut self, request: Request<Command>) -> trc::Result<()> {
self.state = State::NotAuthenticated { auth_failures: 0 };
self.write_bytes(
StatusResponse::completed(Command::Unauthenticate)
.with_tag(request.tag)
.into_bytes(),
)
.await
}
}
pub fn decode_challenge_plain(challenge: &[u8]) -> Result<Credentials<String>, &'static str> {
let mut username = Vec::new();
let mut secret = Vec::new();
let mut arg_num = 0;
for &ch in challenge {
if ch != 0 {
if arg_num == 1 {
username.push(ch);
} else if arg_num == 2 {
secret.push(ch);
}
} else {
arg_num += 1;
}
}
match (String::from_utf8(username), String::from_utf8(secret)) {
(Ok(username), Ok(secret)) if !username.is_empty() && !secret.is_empty() => {
Ok((username, secret).into())
}
_ => Err("Invalid AUTH=PLAIN challenge."),
}
}
pub fn decode_challenge_oauth(challenge: &[u8]) -> Result<Credentials<String>, &'static str> {
let mut saw_marker = true;
for (pos, &ch) in challenge.iter().enumerate() {
if saw_marker {
if challenge
.get(pos..)
.map_or(false, |b| b.starts_with(b"auth=Bearer "))
{
let pos = pos + 12;
return Ok(Credentials::OAuthBearer {
token: String::from_utf8(
challenge
.get(
pos..pos
+ challenge
.get(pos..)
.and_then(|c| c.iter().position(|&ch| ch == 0x01))
.unwrap_or(challenge.len()),
)
.ok_or("Failed to find end of bearer token")?
.to_vec(),
)
.map_err(|_| "Bearer token is not a valid UTF-8 string.")?,
});
} else {
saw_marker = false;
}
} else if ch == 0x01 {
saw_marker = true;
}
}
Err("Failed to find 'auth=Bearer' in challenge.")
}
|
