Steps towards encryption

- Added certstore and retrieval of the local trust root.
- Major work on keeping the context between calls to the milter.
- Added a context for an email in processing
- Added Husk specific errors

src/types/errors.rs

@@ -0,0 +1,15 @@
+//
+// Husk milter
+//
+// Error typ
+//
+
+use thiserror::Error;
+
+#[derive(Error, Debug)]
+pub enum HuskError {
+    #[error("Cannot find local trust root")]
+    NoLocalTrustRoot,
+    #[error("Cannot access cert store")]
+    NoCertStore
+}

src/types/husk_context.rs

@@ -4,21 +4,41 @@
 // Context
 //
 
-pub struct HuskContext {
-    pub sender: Option<String>,
+use anyhow;
+use std::path::PathBuf;
+use sequoia_openpgp::Cert;
+use sequoia_cert_store::CertStore;
+use sequoia_directories::Home;
+
+use crate::{config::HuskConfig, crypto};
+use crate::types::mail_context::MailContext;
+
+pub struct HuskContext<'hc> {
+    pub cert_store: CertStore<'hc>,
+    pub local_trust_root: Cert,
+    pub mail: MailContext<'hc>,
 }
 
-impl HuskContext {
-    
+impl<'hc> HuskContext<'hc> {
+
     /// Create a new HuskContext instance
-    pub fn new() -> Option<HuskContext> {
-        Some(HuskContext {
-            sender: None
+    pub fn new(config: &HuskConfig) -> anyhow::Result<HuskContext<'hc>> {
+
+        let sequoia_home = Home::new(PathBuf::from(&config.sequoia_home))?;
+        let cert_store_base = sequoia_home.data_dir(sequoia_directories::Component::CertD);
+        let cert_store = CertStore::open(cert_store_base)?;
+
+        let local_trust_root = crypto::get_local_trust_root(&cert_store)?;
+
+        Ok(HuskContext {
+            cert_store,
+            local_trust_root,
+            mail: MailContext::new(),
         })
     }
 
     pub fn set_sender(&mut self, sender: String) {
-        self.sender = Some(sender);
+        self.mail.set_sender(sender);
     }
 
 }

src/types/mail_context.rs

@@ -0,0 +1,37 @@
+//
+// Husk milter
+//
+// Mail Context
+//
+
+use std::ffi::CString;
+
+use sequoia_openpgp::cert::ValidCert;
+
+pub struct Recipient<'r> {
+    pub email: CString,
+    pub cert: Option<ValidCert<'r>>,
+}
+
+pub struct MailContext<'c> {
+    pub sender:     Option<String>,
+    pub recipients: Vec<Recipient<'c>>,
+    // header
+    // body
+    // body size
+}
+
+impl MailContext<'_> {
+
+    pub fn new() -> Self {
+        MailContext {
+            sender: None,
+            recipients: Vec::new(),
+        }
+    }
+
+    pub fn set_sender(&mut self, sender: String) {
+        self.sender = Some(sender);
+    }
+
+}

src/types/mod.rs

@@ -1 +1,3 @@
 pub mod husk_context;
+pub mod mail_context;
+pub mod errors;