Add certificates

- Refactor `Recipient` out of `MailContext`.
- Add lookup of authenticated certificates for recipients.

src/crypto.rs

@@ -4,12 +4,18 @@
 // cryptographic functions
 //
 
+use std::sync::Arc;
+
 use anyhow;
 use sequoia_openpgp::parse::Parse;
 use sequoia_openpgp::{Fingerprint, Cert};
 use sequoia_openpgp::cert::raw::RawCertParser;
-use sequoia_cert_store::CertStore;
+use sequoia_cert_store::{Store, CertStore, LazyCert};
+use sequoia_wot::{self as wot};
+use wot::store::Store as _;
+
 use crate::types::errors::HuskError;
+use crate::types::husk_context::HuskContext;
 
 pub fn get_local_trust_root(cert_store: &CertStore) -> anyhow::Result<Cert> {
 
@@ -45,3 +51,34 @@ pub fn get_local_trust_root(cert_store: &CertStore) -> anyhow::Result<Cert> {
     }
 
 }
+
+pub fn get_certificates<'hc>(context: &HuskContext<'hc>, email: &str) 
+    -> Vec<Arc<LazyCert<'hc>>> {
+
+    let cert_store = &context.cert_store;
+    let trust_roots = vec![(context.local_trust_root.fingerprint(), wot::FULLY_TRUSTED)];
+    let wot_store = wot::store::CertStore::from_store(cert_store, &context.policy, None);
+    let nb = wot::NetworkBuilder::rooted(&wot_store, &*trust_roots);
+    let n = nb.build();
+
+    let bindings: Vec<_> = n.lookup_synopses_by_email(email)
+        .into_iter()
+        .map(|(fp, userid)| (fp, Some(userid)))
+        .collect();
+
+    let mut result = vec![];
+    for (fpr, some_userid) in bindings {
+        if let Some(userid) = some_userid {
+            let paths = n.authenticate(userid, &fpr, wot::FULLY_TRUSTED);
+            if paths.len() > 0 {
+                log::debug!("authenticated!!!");
+                for (path, _) in paths.iter() {
+                    if let Ok(cert) = cert_store.lookup_by_cert_fpr(&path.target().fingerprint()) {
+                        result.push(cert);
+                    }
+                }
+            }
+        }
+    }
+    result
+}