Tor support

- Add support for using Tor via a socks5 proxy.
- Tor usage of the milter and the updater process are configured
  separately.
- Restructure the config file and add some documentation.

Cargo.lock

@@ -1292,6 +1292,7 @@ dependencies = [
  "log",
  "log4rs",
  "rand 0.10.2",
+ "reqwest",
  "sequoia-cert-store",
  "sequoia-directories",
  "sequoia-keystore",

Cargo.toml

@@ -22,6 +22,8 @@ lettre = "0.11.22"
 log = "0.4.30"
 log4rs = "1.3.0"
 rand = "0.10.2"
+# the reqwest version has to be the same sequoia-net reexports!
+reqwest = { version = "0.12", features = ["socks"] }
 sequoia-cert-store = "0.7.3"
 sequoia-directories = "0.1.0"
 sequoia-keystore = "0.7.2"

config/config.toml

@@ -1,17 +1,60 @@
 #
 # Husk config file
 #
-connection = "localhost:3000"
 
+# The directory for anything Sequoia PGP related (keystore, certstore).
+# 
+# default: /var/lib/husk
 sequoia_home = "/tmp/sq_home"
 
-#keyservers = [ "hkps://keys.openpgp.org/", "hkps://mail-api.proton.me", "hkps://keys.mailvelope.com", "hkps://keyserver.ubuntu.com", "hkps://sks.pod01.fleetstreetops.com" ]
+[milter]
+# IP and port the milter will listen on.
+#
+# no default, must be specified.
+connection = "localhost:3000"
+
+# Keyservers to use for key lookup.
+#
+# Example:
+# keyservers = [ "hkps://keys.openpgp.org/", "hkps://mail-api.proton.me", "hkps://keys.mailvelope.com", "hkps://keyserver.ubuntu.com", "hkps://sks.pod01.fleetstreetops.com" ]
+#
+# The default is the empty list, which prevents keyserver lookups.
 keyservers = [ "hkp://example.com" ]
 
+# Location of the pid file of the milter.
+#
+# default: /var/lib/husk/husk.pid
+
+# Subject header lines are protected (exchanged).
+#
+# Specify your replacement string:
+# subject_replacement = "Encrypted message"
+#
+# default: "..."
+
+# Tor usage: If configured, the milter will use Tor via the specified
+# sock5 proxy.
+#
+# use_tor_via = "socks5://localhost:9050/"
+#
+# default: unconfigured, meaning: no usage of Tor.
+
 [updater]
+
+# The interval between two update requests for a certificate are
+# random. 
+#
+# wait_min and wait_max specify the range for that randomness.
+# defaults:
+# min_wait = 5
+# max_wait = 3600
 wait_min = 1
 wait_max = 2
 
+# Tor usage of the updater process. Semantics (and default) are the same 
+# as with the milter.
+use_tor_via = "socks5://localhost:9050/"
+
 [logging.appenders.console]
 kind = "console"
 [logging.appenders.console.encoder]

src/common/crypto.rs

@@ -30,6 +30,7 @@ use sequoia_wot::{self as wot, CertSynopsis};
 use wot::store::Store as _;
 use wot::{Depth, Path};
 
+use crate::config::TorConnectorType;
 use crate::types::errors::HuskError;
 use crate::types::husk_context::HuskContext;
 use crate::types::introducer::Introducer;
@@ -125,11 +126,23 @@ async fn query_online_sources<'hc>(context: &HuskContext<'hc>, query: OnlineQuer
     log::debug!("remote lookup for {:?}", query);
 
     let mut jobs = JoinSet::new();
-    let http_client = sequoia_net::reqwest::Client::builder()
+    let mut http_client_builder = sequoia_net::reqwest::Client::builder()
         .user_agent(USER_AGENT)
         .connect_timeout(CONNECT_TIMEOUT)
-        .timeout(REQUEST_TIMEOUT)
-        .build()?;
+        .timeout(REQUEST_TIMEOUT);
+
+    if let TorConnectorType::SocksProxy(socks_url) = &context.use_tor_via {
+        // Configure the use of a tor proxy.
+        let mut nonce: [u8; 4] = [0; 4];
+        sequoia_openpgp::crypto::random(&mut nonce[..])?;
+        let nonce: String = sequoia_openpgp::fmt::hex::encode(&nonce);
+        let url: String = format!("socks5h://anonymous:{}@{}", nonce, socks_url);
+
+        http_client_builder = http_client_builder
+            .proxy(sequoia_net::reqwest::Proxy::all(url)?);
+    }
+
+    let http_client = http_client_builder.build()?;
 
     // local function to check certificates for usability
     let collect_certs = |certs: Vec<Result<Cert, anyhow::Error>>, query: OnlineQuery, policy: &StandardPolicy| {
@@ -152,8 +165,8 @@ async fn query_online_sources<'hc>(context: &HuskContext<'hc>, query: OnlineQuer
                             }
                         }
                     },
-                    OnlineQuery::Fingerprint(_) => {
-                        found = true;
+                    OnlineQuery::Fingerprint(f) => {
+                        found = cert.fingerprint() == f;
                     }
                 }
 
@@ -193,9 +206,19 @@ async fn query_online_sources<'hc>(context: &HuskContext<'hc>, query: OnlineQuer
                 let q = query.clone();
                 match query {
                     OnlineQuery::Email(e) => {
+                        match ks.search(e.as_str()).await {
+                            Ok(certs) => {
+                                partial_result = collect_certs(certs, q, &p);
+                            }
+                            Err(e) => {
+                                log::debug!("Error: {}", e.to_string());
+                            }
+                        }
+                        /*
                         if let Ok(certs) = ks.search(e.as_str()).await {
                             partial_result = collect_certs(certs, q, &p);
                         }
+                        */
                         partial_result
                     },
                     OnlineQuery::Fingerprint(f) => {
@@ -934,7 +957,8 @@ jk6lh01Ej9QTGQ==
             introducers: Vec::new(),
             keyservers: Vec::new(),
             subject_replacement: "...".into(),
-            mail: MailContext::new()
+            mail: MailContext::new(),
+            use_tor_via: crate::config::TorConnectorType::NotUsed,
         };
 
         // store the local trust root

src/config.rs

@@ -9,6 +9,7 @@ use toml;
 use log4rs;
 
 use crate::types::errors::HuskError;
+use crate::types::defaults::CONNECTION;
 use crate::types::defaults::CONSOLE_LOGGING;
 use crate::types::defaults::UPDATER_PID_FILE_LOCATION;
 use crate::types::defaults::UPDATER_STATE_FILE_LOCATION;
@@ -17,21 +18,55 @@ use crate::types::defaults::UPDATER_WAIT_MAX;
 use crate::types::defaults::PID_FILE_LOCATION;
 use crate::types::defaults::SUBJECT_REPLACEMENT;
 
+#[derive(Deserialize, Debug, Clone)]
+pub enum TorConnectorType {
+    NotUsed,
+    Errornous,
+    SocksProxy(String),
+    Arti,
+}
+
+impl From<Option<String>> for TorConnectorType {
+    fn from(value: Option<String>) -> Self {
+        match value {
+            Some(v) => {
+                if v.to_ascii_lowercase() == "arti" {
+                    TorConnectorType::Arti
+                } else {
+                    if v.starts_with("socks5://") {
+                        TorConnectorType::SocksProxy(v[9..].to_string())
+                    } else {
+                        TorConnectorType::Errornous
+                    }
+                }
+            },
+            None => TorConnectorType::NotUsed,
+        }
+    }
+}
+
+#[derive(Deserialize, Debug, Clone)]
+pub struct MilterConfig {
+    pub connection: String,
+    pub pid_file: Option<String>,
+    pub keyservers: Option<Vec<String>>,
+    pub subject_replacement: Option<String>,
+    use_tor_via: Option<String>,
+}
+
 #[derive(Deserialize, Debug, Clone)]
 pub struct UpdaterConfig {
     pub wait_min: Option<u32>,
     pub wait_max: Option<u32>,
     pub pid_file: Option<String>,
     pub state_file: Option<String>,
+    use_tor_via: Option<String>,
 }
 
 #[derive(Deserialize, Debug, Clone)]
 pub struct HuskConfig {
-    pub connection: String,
     pub sequoia_home: String,
-    pub keyservers: Option<Vec<String>>,
-    pub subject_replacement: Option<String>,
-    pub pid_file: Option<String>,
+    milter: Option<MilterConfig>,
     updater: Option<UpdaterConfig>,
     logging: Option<toml::Value>,
 }
@@ -77,28 +112,47 @@ impl HuskConfig {
         Ok(())
     }
 
-    pub fn get_keyservers(&self) -> Vec<String> {
-        if let Some(kss) = &self.keyservers {
-            kss.clone()
+    pub fn get_connection(&self) -> String {
+        if let Some(milter_config) = &self.milter {
+            milter_config.connection.clone()
         } else {
-            Vec::new()
+            CONNECTION.to_string()
         }
     }
 
+    pub fn get_milter_tor_usage(&self) -> TorConnectorType {
+        if let Some(milter_config) = &self.milter {
+            milter_config.use_tor_via.clone().into()
+        } else {
+            TorConnectorType::NotUsed
+        }
+    }
+
+    pub fn get_keyservers(&self) -> Vec<String> {
+        if let Some(milter_config) = &self.milter {
+            if let Some(kss) = &milter_config.keyservers {
+                return kss.clone();
+            }
+        }
+        Vec::new()
+    }
+
     pub fn get_subject_replacement(&self) -> String {
-        if let Some(replacement) = &self.subject_replacement {
-            replacement.clone()
-        } else {
-            SUBJECT_REPLACEMENT.to_string()
+        if let Some(milter_config) = &self.milter {
+            if let Some(replacement) = &milter_config.subject_replacement {
+                return replacement.clone();
+            }
         }
+        SUBJECT_REPLACEMENT.to_string()
     }
 
     pub fn get_pid_file(&self) -> String {
-        if let Some(pid_file) = &self.pid_file {
-            pid_file.clone()
-        } else {
-            PID_FILE_LOCATION.to_string()
+        if let Some(milter_config) = &self.milter {
+            if let Some(pid_file) = &milter_config.pid_file {
+                return pid_file.clone();
+            }
         }
+        PID_FILE_LOCATION.to_string()
     }
 
     pub fn get_updater_pid_file(&self) -> String {
@@ -147,6 +201,14 @@ impl HuskConfig {
             UPDATER_WAIT_MAX
         }
     }
+
+    pub fn get_updater_tor_usage(&self) -> TorConnectorType {
+        if let Some(updater_config) = &self.updater {
+            updater_config.use_tor_via.clone().into()
+        } else {
+            TorConnectorType::NotUsed
+        }
+    }
 }
 
 pub type HuskConfigContainer = Arc<Mutex<HuskConfig>>;
@@ -168,12 +230,9 @@ mod tests {
     #[test]
     fn subject_line() {
         let config = HuskConfig {
-            connection: "".into(),
             sequoia_home: "".into(),
-            keyservers: None,
-            subject_replacement: None,
             logging: None,
-            pid_file: None,
+            milter: None,
             updater: None,
         };
 

src/daemon/mod.rs

@@ -33,7 +33,7 @@ impl Daemon {
 
         let config: HuskConfig = config_container.clone().into();
 
-        let listener = TcpListener::bind(&config.connection)
+        let listener = TcpListener::bind(&config.get_connection())
             .await
             .expect(" opening milter socket");
 
@@ -116,6 +116,7 @@ impl Daemon {
             // setup Context
             match HuskContext::new(&config) {
                 Ok(mut context) => {
+                    context.for_milter(&config);
                     context.set_sender(sender.unwrap());
                     cx.data = Some(context);
                     Status::Continue

src/types/defaults.rs

@@ -1,5 +1,8 @@
 //! Defaults
 
+/// Default host and port of the milter.
+pub const CONNECTION: &str = "localhost:3000";
+
 pub const CONFIG_FILE_LOCATION: &str = "/etc/husk/config.toml";
 
 /// If encrypting a mail, the subject is moved into the encrypted body

src/types/husk_context.rs

@@ -17,7 +17,7 @@ use sequoia_cert_store::CertStore;
 use sequoia_directories::Home;
 use sequoia_keystore::Key;
 
-use crate::config::HuskConfig;
+use crate::config::{HuskConfig, TorConnectorType};
 use crate::common::crypto;
 use crate::types::mail_context::MailContext;
 
@@ -32,6 +32,7 @@ pub struct HuskContext<'hc> {
     pub keyservers: Vec<String>,
     pub subject_replacement: String,
     pub mail: MailContext<'hc>,
+    pub use_tor_via: TorConnectorType,
 }
 
 impl<'hc> HuskContext<'hc> {
@@ -82,6 +83,7 @@ impl<'hc> HuskContext<'hc> {
             keyservers: config.get_keyservers(),
             subject_replacement: config.get_subject_replacement(),
             mail: MailContext::new(),
+            use_tor_via: TorConnectorType::NotUsed,
         })
     }
 
@@ -109,4 +111,12 @@ impl<'hc> HuskContext<'hc> {
         self.mail.add_recipient(rcpt, certs)
     }
 
+    pub fn for_milter(&mut self, config: &HuskConfig) {
+        self.use_tor_via = config.get_milter_tor_usage();
+    }
+
+    pub fn for_updater(&mut self, config: &HuskConfig) {
+        self.use_tor_via = config.get_updater_tor_usage();
+    }
+
 }

src/updater/mod.rs

@@ -41,15 +41,16 @@ impl Updater {
             let mut updater_state = UpdaterState::thaw(state_path)
                 .await
                 .map_err(|e| { stay = false; e })?;
-            let context = &HuskContext::without_signkey(&c)?;
-            updater_state.refresh(context);
+            let mut context = HuskContext::without_signkey(&c)?;
+            context.for_updater(&c);
+            updater_state.refresh(&context);
 
             if let Some(fpr) = updater_state.next() {
                 log::debug!("try to update {}", fpr.to_hex());
 
                 let stats = MergePublicCollectStats::new();
 
-                let certs = crypto::lookup_fingerprint(context, fpr.to_hex().as_str()).await?;
+                let certs = crypto::lookup_fingerprint(&context, fpr.to_hex().as_str()).await?;
                 if !certs.is_empty() {
                     for cert in certs {
                         let cert = Arc::new(LazyCert::from_cert(cert));