From feb6f7be519aeb7689b470eee7fdeabf213cb80e Mon Sep 17 00:00:00 2001
From: Heiko Schaefer <heiko@schaefer.name>
Date: Sat, 7 Aug 2021 00:18:13 +0200
Subject: [PATCH] Implement get_pub_key()

---
 card-functionality/src/main.rs    | 46 +++++++++++++++++++++++++++++++
 openpgp-card/src/apdu/commands.rs |  5 ++++
 openpgp-card/src/card_app.rs      |  7 +++++
 openpgp-card/src/keys.rs          | 24 +++++++++++++++-
 4 files changed, 81 insertions(+), 1 deletion(-)

diff --git a/card-functionality/src/main.rs b/card-functionality/src/main.rs
index ccec2d2..219b98c 100644
--- a/card-functionality/src/main.rs
+++ b/card-functionality/src/main.rs
@@ -31,6 +31,7 @@ use std::time::SystemTime;
 use thiserror::Error;
 
 use sequoia_openpgp::parse::Parse;
+use sequoia_openpgp::types::Timestamp;
 use sequoia_openpgp::Cert;
 
 use openpgp_card::card_app::CardApp;
@@ -233,6 +234,46 @@ fn test_keygen(
     Ok(vec![])
 }
 
+/// Construct public key based on data from the card
+fn test_get_pub(
+    ca: &mut CardApp,
+    _param: &[&str],
+) -> Result<TestOutput, TestError> {
+    let ard = ca.get_app_data()?;
+    let key_gen = CardApp::get_key_generation_times(&ard)?;
+
+    // --
+
+    let sig = ca.get_pub_key(KeyType::Signing)?;
+    let ts = Timestamp::from(key_gen.signature().unwrap().get()).into();
+    let key = openpgp_card_sequoia::public_key_material_to_key(&sig, ts)?;
+
+    println!(" sig key data from card -> {:x?}", key);
+
+    // --
+
+    let dec = ca.get_pub_key(KeyType::Decryption)?;
+    let ts = Timestamp::from(key_gen.decryption().unwrap().get()).into();
+    let key = openpgp_card_sequoia::public_key_material_to_key(&dec, ts)?;
+
+    println!(" dec key data from card -> {:x?}", key);
+
+    // --
+
+    let auth = ca.get_pub_key(KeyType::Authentication)?;
+    let ts = Timestamp::from(key_gen.authentication().unwrap().get()).into();
+    let key = openpgp_card_sequoia::public_key_material_to_key(&auth, ts)?;
+
+    println!(" auth key data from card -> {:x?}", key);
+
+    // FIXME: assert that key FP is equal to FP from card
+
+    // ca.generate_key(fp, KeyType::Decryption)?;
+    // ca.generate_key(fp, KeyType::Authentication)?;
+
+    Ok(vec![])
+}
+
 fn test_reset(
     ca: &mut CardApp,
     _param: &[&str],
@@ -358,6 +399,11 @@ fn main() -> Result<()> {
     for mut card in cards {
         println!("** Run tests on card {:?} **", card);
 
+        println!("Get pubkey");
+        let _ = run_test(&mut card, test_get_pub, &[])?;
+
+        panic!();
+
         // println!("Caps");
         // let _ = run_test(&mut card, test_print_caps, &[])?;
         //
diff --git a/openpgp-card/src/apdu/commands.rs b/openpgp-card/src/apdu/commands.rs
index 4621906..c43ff6b 100644
--- a/openpgp-card/src/apdu/commands.rs
+++ b/openpgp-card/src/apdu/commands.rs
@@ -131,3 +131,8 @@ pub fn signature(data: Vec<u8>) -> Command {
 pub fn gen_key(data: Vec<u8>) -> Command {
     Command::new(0x00, 0x47, 0x80, 0x00, data)
 }
+
+/// Creates new APDU for "Reading of public key template"
+pub fn get_pub_key(data: Vec<u8>) -> Command {
+    Command::new(0x00, 0x47, 0x81, 0x00, data)
+}
diff --git a/openpgp-card/src/card_app.rs b/openpgp-card/src/card_app.rs
index e54bdb1..f68505a 100644
--- a/openpgp-card/src/card_app.rs
+++ b/openpgp-card/src/card_app.rs
@@ -572,4 +572,11 @@ impl CardApp {
         // FIXME: specify algo; pass in algo list?
         keys::gen_key_with_metadata(self, fp_from_pub, key_type)
     }
+
+    pub fn get_pub_key(
+        &mut self,
+        key_type: KeyType,
+    ) -> Result<PublicKeyMaterial, OpenpgpCardError> {
+        keys::get_pub_key(self, key_type)
+    }
 }
diff --git a/openpgp-card/src/keys.rs b/openpgp-card/src/keys.rs
index 294e91c..c7997e1 100644
--- a/openpgp-card/src/keys.rs
+++ b/openpgp-card/src/keys.rs
@@ -19,7 +19,8 @@ use crate::{
     RSAKey,
 };
 
-/// `fp_from_pub` calculates the fingerprint for a public key data object
+/// `gen_key_with_metadata` calculates the fingerprint for a public key
+/// data object
 pub(crate) fn gen_key_with_metadata(
     card_app: &mut CardApp,
     fp_from_pub: fn(&PublicKeyMaterial, SystemTime) -> Result<[u8; 20]>,
@@ -116,6 +117,27 @@ pub(crate) fn gen_key(
     Ok(pubkey)
 }
 
+pub(crate) fn get_pub_key(
+    card_app: &mut CardApp,
+    key_type: KeyType,
+) -> Result<PublicKeyMaterial, OpenpgpCardError> {
+    println!("get pub key for {:?}", key_type);
+
+    let card_client = card_app.card();
+
+    // get public key
+    let crt = get_crt(key_type)?;
+    let get_pub_key_cmd = commands::get_pub_key(crt.serialize().to_vec());
+
+    let resp = apdu::send_command(card_client, get_pub_key_cmd, true)?;
+    resp.check_ok()?;
+
+    let tlv = Tlv::try_from(resp.data()?)?;
+    let pubkey = tlv_to_pubkey(&tlv)?;
+
+    Ok(pubkey)
+}
+
 /// Upload an explicitly selected Key to the card as a specific KeyType.
 ///
 /// The client needs to make sure that the key is suitable for `key_type`.