From e695e8171a57ffd82c09f9719a99eb10463eb8f7 Mon Sep 17 00:00:00 2001
From: Heiko Schaefer <heiko@schaefer.name>
Date: Tue, 16 Nov 2021 19:18:34 +0100
Subject: [PATCH] Implement 'Display' for PublicKeyMaterial

---
 openpgp-card/Cargo.toml         |  1 +
 openpgp-card/src/crypto_data.rs | 20 ++++++++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/openpgp-card/Cargo.toml b/openpgp-card/Cargo.toml
index ce0cf9e..9dd5929 100644
--- a/openpgp-card/Cargo.toml
+++ b/openpgp-card/Cargo.toml
@@ -14,6 +14,7 @@ documentation = "https://docs.rs/crate/openpgp-card"
 [dependencies]
 nom = "6"
 hex-literal = "0.3"
+hex-slice = "0.1"
 anyhow = "1"
 thiserror = "1"
 env_logger = "0.8"
diff --git a/openpgp-card/src/crypto_data.rs b/openpgp-card/src/crypto_data.rs
index 98ac9bd..15be615 100644
--- a/openpgp-card/src/crypto_data.rs
+++ b/openpgp-card/src/crypto_data.rs
@@ -120,6 +120,26 @@ pub enum PublicKeyMaterial {
     E(EccPub),
 }
 
+impl std::fmt::Display for PublicKeyMaterial {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        use hex_slice::AsHex;
+
+        match self {
+            Self::R(rsa) => {
+                write!(
+                    f,
+                    "RSA, n: {:02X}, e: {:02X}",
+                    rsa.n.plain_hex(false),
+                    rsa.v.plain_hex(false)
+                )
+            }
+            Self::E(ecc) => {
+                write!(f, "ECC, data: {:02X}", ecc.data.plain_hex(false))
+            }
+        }
+    }
+}
+
 /// RSA-specific container for public key material from an OpenPGP card.
 #[derive(Debug)]
 #[non_exhaustive]