De-duplicate parsing recipients from SubjectPublicKeyInfo

src/builder.rs

@@ -1,7 +1,7 @@
 use rand::{rngs::OsRng, RngCore};
 use x509::RelativeDistinguishedName;
 use yubikey::{
-    certificate::{Certificate, PublicKeyInfo},
+    certificate::Certificate,
     piv::{generate as yubikey_generate, AlgorithmId, RetiredSlotId, SlotId},
     Key, PinPolicy, TouchPolicy, YubiKey,
 };
@@ -106,12 +106,7 @@ impl IdentityBuilder {
             touch_policy,
         )?;
 
-        let recipient = match &generated {
-            PublicKeyInfo::EcP256(pubkey) => {
-                Recipient::from_encoded(pubkey).expect("YubiKey generates a valid pubkey")
-            }
-            _ => unreachable!(),
-        };
+        let recipient = Recipient::from_spki(&generated).expect("YubiKey generates a valid pubkey");
         let stub = Stub::new(yubikey.serial(), slot, &recipient);
 
         // Pick a random serial for the new self-signed certificate.

src/key.rs

@@ -15,7 +15,7 @@ use std::iter;
 use std::thread::sleep;
 use std::time::{Duration, Instant, SystemTime};
 use yubikey::{
-    certificate::{Certificate, PublicKeyInfo},
+    certificate::Certificate,
     piv::{decrypt_data, AlgorithmId, RetiredSlotId, SlotId},
     reader::{Context, Reader},
     MgmKey, PinPolicy, Serial, TouchPolicy, YubiKey,
@@ -459,11 +459,10 @@ impl Stub {
         // Read the pubkey from the YubiKey slot and check it still matches.
         let (cert, pk) = match Certificate::read(&mut yubikey, SlotId::Retired(self.slot))
             .ok()
-            .and_then(|cert| match cert.subject_pki() {
-                PublicKeyInfo::EcP256(pubkey) => Recipient::from_encoded(pubkey)
+            .and_then(|cert| {
+                Recipient::from_certificate(&cert)
                     .filter(|pk| pk.tag() == self.tag)
-                    .map(|pk| (cert, pk)),
-                _ => None,
+                    .map(|pk| (cert, pk))
             }) {
             Some(pk) => pk,
             None => {

src/main.rs

@@ -13,7 +13,6 @@ use i18n_embed::{
 use lazy_static::lazy_static;
 use rust_embed::RustEmbed;
 use yubikey::{
-    certificate::PublicKeyInfo,
     piv::{RetiredSlotId, SlotId},
     reader::Context,
     Key, PinPolicy, Serial, TouchPolicy,
@@ -196,9 +195,9 @@ fn print_single(
     let mut keys = Key::list(&mut yubikey)?.into_iter().filter_map(|key| {
         // - We only use the retired slots.
         // - Only P-256 keys are compatible with us.
-        match (key.slot(), key.certificate().subject_pki()) {
-            (SlotId::Retired(slot), PublicKeyInfo::EcP256(pubkey)) => {
-                p256::Recipient::from_encoded(pubkey).map(|r| (key, slot, r))
+        match key.slot() {
+            SlotId::Retired(slot) => {
+                p256::Recipient::from_certificate(key.certificate()).map(|r| (key, slot, r))
             }
             _ => None,
         }
@@ -244,12 +243,9 @@ fn print_multiple(
             };
 
             // Only P-256 keys are compatible with us.
-            let recipient = match key.certificate().subject_pki() {
-                PublicKeyInfo::EcP256(pubkey) => match p256::Recipient::from_encoded(pubkey) {
-                    Some(recipient) => recipient,
-                    None => continue,
-                },
-                _ => continue,
+            let recipient = match p256::Recipient::from_certificate(key.certificate()) {
+                Some(recipient) => recipient,
+                None => continue,
             };
 
             let stub = key::Stub::new(yubikey.serial(), slot, &recipient);
@@ -429,20 +425,17 @@ fn main() -> Result<(), Error> {
             .map(|&slot| {
                 keys.iter()
                     .find(|key| key.slot() == SlotId::Retired(slot))
-                    .map(|key| match key.certificate().subject_pki() {
-                        PublicKeyInfo::EcP256(pubkey) => {
-                            p256::Recipient::from_encoded(pubkey).map(|_| {
-                                // Cache the details we need to display to the user.
-                                let (_, cert) =
-                                    x509_parser::parse_x509_certificate(key.certificate().as_ref())
-                                        .unwrap();
-                                let (name, _) = util::extract_name(&cert, true).unwrap();
-                                let created = cert.validity().not_before.to_rfc2822();
+                    .map(|key| {
+                        p256::Recipient::from_certificate(key.certificate()).map(|_| {
+                            // Cache the details we need to display to the user.
+                            let (_, cert) =
+                                x509_parser::parse_x509_certificate(key.certificate().as_ref())
+                                    .unwrap();
+                            let (name, _) = util::extract_name(&cert, true).unwrap();
+                            let created = cert.validity().not_before.to_rfc2822();
 
-                                format!("{}, created: {}", name, created)
-                            })
-                        }
-                        _ => None,
+                            format!("{}, created: {}", name, created)
+                        })
                     })
             })
             .collect();
@@ -492,12 +485,8 @@ fn main() -> Result<(), Error> {
             };
 
             if let Some(key) = keys.iter().find(|key| key.slot() == SlotId::Retired(slot)) {
-                let recipient = match key.certificate().subject_pki() {
-                    PublicKeyInfo::EcP256(pubkey) => {
-                        p256::Recipient::from_encoded(pubkey).expect("We checked this above")
-                    }
-                    _ => unreachable!(),
-                };
+                let recipient = p256::Recipient::from_certificate(key.certificate())
+                    .expect("We checked this above");
 
                 if Confirm::new()
                     .with_prompt(i18n_embed_fl::fl!(

src/p256.rs

@@ -1,6 +1,8 @@
 use bech32::{ToBase32, Variant};
 use p256::elliptic_curve::sec1::{FromEncodedPoint, ToEncodedPoint};
 use sha2::{Digest, Sha256};
+use yubikey::{certificate::PublicKeyInfo, Certificate};
+
 use std::fmt;
 
 use crate::RECIPIENT_PREFIX;
@@ -42,11 +44,22 @@ impl Recipient {
         }
     }
 
+    pub(crate) fn from_certificate(cert: &Certificate) -> Option<Self> {
+        Self::from_spki(cert.subject_pki())
+    }
+
+    pub(crate) fn from_spki(spki: &PublicKeyInfo) -> Option<Self> {
+        match spki {
+            PublicKeyInfo::EcP256(pubkey) => Self::from_encoded(pubkey),
+            _ => None,
+        }
+    }
+
     /// Attempts to parse a valid YubiKey recipient from its SEC-1 encoding.
     ///
     /// This accepts both compressed (as used by the plugin) and uncompressed (as used in
     /// the YubiKey certificate) encodings.
-    pub(crate) fn from_encoded(encoded: &p256::EncodedPoint) -> Option<Self> {
+    fn from_encoded(encoded: &p256::EncodedPoint) -> Option<Self> {
         p256::PublicKey::from_encoded_point(encoded).map(Recipient)
     }