Refactoring loading of config file

- let `HuskConfig::load` return a `Result` instead of an `Option`.
- added comments

src/config.rs

@@ -2,10 +2,13 @@
 // Parsing the config file
 //
 
+use anyhow;
 use std::fs;
 use std::sync::{Arc, Mutex};
 use serde_derive::Deserialize;
 
+use crate::types::errors::HuskError;
+
 #[derive(Deserialize, Debug, Clone)]
 pub struct HuskConfig {
     pub connection: String,
@@ -15,20 +18,18 @@ pub struct HuskConfig {
 
 impl HuskConfig {
 
-    pub fn load(path: &String) -> Option<Self> {
+    pub fn load(path: &String) -> anyhow::Result<Self> {
         match fs::read_to_string(path) {
             Ok(data) => {
                 match toml::from_str(data.as_str()) {
-                    Ok(configuration) => Some(configuration),
+                    Ok(configuration) => Ok(configuration),
                     Err(e) => {
-                        eprintln!("Error while parsing config file: {:?}", e);
-                        None
+                        Err(HuskError::ConfigFileParseError(e.to_string()).into())
                     }
                 }
             },
             Err(e) => {
-                eprintln!("Error while reading config file: {:?}", e);
-                None
+                Err(HuskError::ConfigFileOpenError(e.to_string()).into())
             }
         }
     }

src/crypto.rs

@@ -24,6 +24,8 @@ use crate::types::husk_context::HuskContext;
 use crate::types::introducer::Introducer;
 use crate::types::recipient::Recipient;
 
+/// Returns the local trust root from the cert_store. If the trust root
+/// cannot be found, it returns an error.
 pub fn get_local_trust_root(cert_store: &CertStore) -> anyhow::Result<Cert> {
 
     let root = cert_store.certd()
@@ -59,6 +61,9 @@ pub fn get_local_trust_root(cert_store: &CertStore) -> anyhow::Result<Cert> {
 
 }
 
+/// Returns all certificates with an authenticated binding to user id 'email'.
+/// The certificates are not checked for usefulness (for instance, they might
+/// miss an encryption subkey).
 pub fn get_certificates<'hc>(context: &HuskContext<'hc>, email: &str)
     -> Vec<Arc<LazyCert<'hc>>> {
 
@@ -90,6 +95,7 @@ pub fn get_certificates<'hc>(context: &HuskContext<'hc>, email: &str)
     result
 }
 
+/// Returns all introducers available in cert_store.
 pub fn get_introducers<'c>(cert_store: &CertStore<'c>, policy: &StandardPolicy, local_trust_root: Fingerprint) -> Vec<Introducer> {
 
     let mut result = Vec::new();
@@ -130,6 +136,7 @@ pub fn get_introducers<'c>(cert_store: &CertStore<'c>, policy: &StandardPolicy,
     result
 }
 
+/// Checks if a message contains the OpenPGP artifacts of an encrypted message.
 pub fn is_encrypted(body: &Bytes) -> bool {
 
     let mut ppr = match PacketParser::from_bytes(body) {
@@ -158,6 +165,7 @@ pub fn is_encrypted(body: &Bytes) -> bool {
     false
 }
 
+/// Encrypt a message for `recipients`.
 pub fn encrypt(context: &HuskContext<'_>, body: &Bytes, recipients: &Vec<Recipient>)
     -> anyhow::Result<Bytes> {
 

src/main.rs

@@ -17,13 +17,13 @@ use daemon::Daemon;
 async fn main() {
 
     let config_file = env::args().nth(1).expect("config file missing");
-    let husk_config = HuskConfig::load(&config_file);
-
-    if husk_config.is_none() {
-        eprintln!("Cannot load configuration");
-        process::exit(1);
-    }
-    let husk_config = husk_config.unwrap();
+    let husk_config = match HuskConfig::load(&config_file) {
+        Ok(config) => config,
+        Err(e) => {
+            eprintln!("{:?}", e);
+            process::exit(1);
+        }
+    };
 
     log4rs::init_file(husk_config.logfile_config(), Default::default()).unwrap();
 

src/types/errors.rs

@@ -8,6 +8,10 @@ use thiserror::Error;
 
 #[derive(Error, Debug)]
 pub enum HuskError {
+    #[error("Cannot open config file: {0}")]
+    ConfigFileOpenError(String),
+    #[error("Error while parsing config file: {0}")]
+    ConfigFileParseError(String),
     #[error("Cannot find local trust root")]
     NoLocalTrustRoot,
     #[error("Cannot access cert store")]

src/types/introducer.rs

@@ -19,7 +19,7 @@ impl Introducer {
     pub fn can_introduce(&self, email: &str) -> bool {
         if let Some(regexset) = self.certification.regular_expressions() {
             if regexset.matches_everything() {
-                // return false, because unlimited certifications are 
+                // return false, because unlimited certifications are
                 // ignored.
                 false
             } else {

src/types/mail_context.rs

@@ -12,8 +12,11 @@ use crate::types::recipient::Recipient;
 
 #[derive(PartialEq)]
 pub enum ProtectionPossibility {
+    // no recipient has a cert
     NoProtection,
+    // some recipients have a cert (but not all)
     Partial,
+    // all recipients have a cert
     Full
 }
 
@@ -82,7 +85,8 @@ impl From<&MailContext<'_>> for ProtectionPossibility {
             (true, false) => ProtectionPossibility::Full,
             (true, true) => ProtectionPossibility::Partial,
             (false, true) => ProtectionPossibility::NoProtection,
-            (false, false) => ProtectionPossibility::NoProtection, // this should not occure
+            // (false, false) occurs if there are no recipients
+            (false, false) => ProtectionPossibility::NoProtection,
         }
     }
 }

src/types/recipient.rs

@@ -37,10 +37,14 @@ impl TryFrom<CString> for Recipient<'_> {
 }
 
 impl Recipient<'_> {
+    /// check if this Recipient can encrypt.
+    // XXX: currently this check is naive
     pub fn can_encrypt(&self) -> bool {
         if self.certs.len() == 0 { 
             return false;
         }
+
+        // XXX: add check to see if a cert has encryption capable subkeys
         true
     }
 }