protocol: add connector

Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>

proxmox-protocol/Cargo.toml

@@ -16,3 +16,5 @@ endian_trait = "0.6"
 failure = "0.1"
 libc = "0.2"
 openssl = "0.10"
+serde_json = "1.0"
+url = "1.7"

proxmox-protocol/src/connect.rs

@@ -0,0 +1,225 @@
+//! This module provides a `Connector` used to log into a Proxmox Backup API server and connect to
+//! the proxmox protocol via an HTTP Upgrade request.
+
+use std::io::{Read, Write};
+use std::net::TcpStream;
+
+use failure::{bail, format_err, Error};
+use openssl::ssl::{self, SslStream};
+use url::form_urlencoded;
+
+use crate::Client;
+
+enum Authentication {
+    Password(String),
+    Ticket(String, String),
+}
+
+/// Connector used to log into a Proxmox Backup API server and open a backup protocol connection.
+/// If successful, this will create a `Client` used to communicate over the Proxmox Backup
+/// Protocol.
+pub struct Connector {
+    user: String,
+    server: String,
+    store: String,
+    auth: Option<Authentication>,
+    certificate_validation: bool,
+}
+
+fn build_login(host: &str, user: &str, pass: &str) -> Vec<u8> {
+    let formdata = form_urlencoded::Serializer::new(String::new())
+        .append_pair("username", user)
+        .append_pair("password", pass)
+        .finish();
+
+    format!("\
+        POST /api2/json/access/ticket HTTP/1.1\r\n\
+        host: {}\r\n\
+        content-length: {}\r\n\
+        content-type: application/x-www-form-urlencoded\r\n\
+        \r\n\
+        {}",
+        host,
+        formdata.as_bytes().len(),
+        formdata,
+    )
+    .into_bytes()
+}
+
+fn build_protocol_connect(host: &str, store: &str, ticket: &str, token: &str) -> Vec<u8> {
+    format!("\
+        GET /api2/json/admin/datastore/{}/test-upload HTTP/1.1\r\n\
+        host: {}\r\n\
+        connection: upgrade\r\n\
+        upgrade: proxmox-backup-protocol-1\r\n\
+        cookie: PBSAuthCookie={}\r\n\
+        CSRFPreventionToken: {}\r\n\
+        \r\n",
+        store,
+        host,
+        ticket,
+        token,
+    )
+    .into_bytes()
+}
+
+// Minimalistic http response reader. The only things we care about here are the status code and
+// the payload...
+fn read_http_response<T: Read>(sock: T) -> Result<(u16, Vec<u8>), Error> {
+    use std::io::BufRead;
+    let mut reader = std::io::BufReader::new(sock);
+
+    let mut status = String::new();
+    reader.read_line(&mut status)?;
+
+    let status = status.trim_end();
+    let mut parts = status.splitn(3, ' ');
+    let _version = parts
+        .next()
+        .ok_or_else(|| format_err!("bad http response (missing version)"))?;
+    let code = parts
+        .next()
+        .ok_or_else(|| format_err!("bad http response (missing status code)"))?;
+    let _reason = parts.next();
+
+    let code: u16 = code.parse()?;
+
+    // We need the payload's length if there is one:
+    let mut length: Option<u32> = None;
+    let mut line = String::new();
+    loop {
+        line.clear();
+        reader.read_line(&mut line)?;
+        let line = line.trim_end();
+
+        if line.len() == 0 {
+            break;
+        }
+
+        let parts: Vec<&str> = line.splitn(2, ':').collect();
+        if parts.len() != 2 {
+            bail!("invalid header in http response");
+        }
+
+        let name = parts[0].trim().to_lowercase().to_string();
+        let value = parts[1].trim();
+
+        // The only important header (important to know how much we need to read!)
+        if name == "content-length" {
+            length = Some(value.parse()?);
+        }
+
+        // Don't care about any other header contents currently...
+    }
+
+    match length {
+        None => Ok((code, Vec::new())),
+        Some(length) => {
+            let length = length as usize;
+
+            let mut out = Vec::with_capacity(length);
+            unsafe {
+                out.set_len(length);
+            }
+
+            reader.read_exact(&mut out)?;
+            Ok((code, out))
+        },
+    }
+}
+
+fn parse_login_response(data: &[u8]) -> Result<(String, String), Error> {
+    let value: serde_json::Value = serde_json::from_slice(data)?;
+    let ticket = value["data"]["ticket"]
+        .as_str()
+        .ok_or_else(|| format_err!("no ticket found in login response"))?
+        .to_string();
+    let token = value["data"]["CSRFPreventionToken"]
+        .as_str()
+        .ok_or_else(|| format_err!("no token found in login response"))?
+        .to_string();
+    Ok((ticket, token))
+}
+
+impl Connector {
+    /// Create a new connector for a specified user, server and remote backup store.
+    pub fn new(user: String, server: String, store: String) -> Self {
+        Self {
+            user,
+            server,
+            store,
+            auth: None,
+            certificate_validation: true,
+        }
+    }
+
+    /// Use a password to authenticate with the remote server.
+    pub fn password(mut self, pass: String) -> Self {
+        self.auth = Some(Authentication::Password(pass));
+        self
+    }
+
+    /// Use an already existing ticket to connect to the server.
+    pub fn ticket(mut self, ticket: String, token: String) -> Self {
+        self.auth = Some(Authentication::Ticket(ticket, token));
+        self
+    }
+
+    /// Disable TLS certificate validation.
+    pub fn certificate_validation(mut self, on: bool) -> Self {
+        self.certificate_validation = on;
+        self
+    }
+
+    pub(crate) fn do_connect(self) -> Result<SslStream<TcpStream>, Error> {
+        if self.auth.is_none() {
+            bail!("missing authentication");
+        }
+
+        let stream = TcpStream::connect(&self.server)?;
+
+        let mut connector = ssl::SslConnector::builder(ssl::SslMethod::tls())?;
+        if !self.certificate_validation {
+            connector.set_verify(ssl::SslVerifyMode::NONE);
+        }
+        let connector = connector.build();
+
+        let mut stream = connector.connect(&self.server, stream)?;
+        let (ticket, token) = match self.auth {
+            None => unreachable!(), // checked above
+            Some(Authentication::Password(password)) => {
+                let login_request = build_login(&self.server, &self.user, &password);
+                stream.write_all(&login_request)?;
+
+                let (code, ticket) = read_http_response(&mut stream)?;
+                if code != 200 {
+                    bail!("login failed");
+                }
+
+                parse_login_response(&ticket)?
+            }
+            Some(Authentication::Ticket(ticket, token)) => (ticket, token),
+        };
+
+        let protocol_request = build_protocol_connect(&self.server, &self.store, &ticket, &token);
+        stream.write_all(&protocol_request)?;
+        let (code, _empty_body) = read_http_response(&mut stream)?;
+        if code != 101 {
+            bail!("expected 101 Switching Protocol, received code: {}", code);
+        }
+
+        Ok(stream)
+    }
+
+    /// This creates creates a synchronous client (via blocking I/O), tries to authenticate with
+    /// the server and connect to the protocol endpoint. On success, a `Client` is returned.
+    pub fn connect(self) -> Result<Client<SslStream<TcpStream>>, Error> {
+        let stream = self.do_connect()?;
+
+        let mut client = Client::new(stream);
+        if !client.wait_for_handshake()? {
+            bail!("handshake failed");
+        }
+        Ok(client)
+    }
+}

proxmox-protocol/src/lib.rs

@@ -13,6 +13,9 @@ pub use chunker::*;
 mod client;
 pub use client::*;
 
+mod connect;
+pub use connect::*;
+
 mod types;
 pub use types::*;