key: add show-master-pubkey command

and print public key when generating/importing..

Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>

src/api2/types/mod.rs

@@ -1360,3 +1360,35 @@ pub struct KeyInfo {
     #[serde(skip_serializing_if="Option::is_none")]
     pub hint: Option<String>,
 }
+
+#[api]
+#[derive(Deserialize, Serialize)]
+/// RSA public key information
+pub struct RsaPubKeyInfo {
+    /// Path to key (if stored in a file)
+    #[serde(skip_serializing_if="Option::is_none")]
+    pub path: Option<String>,
+    /// RSA exponent
+    pub exponent: String,
+    /// Hex-encoded RSA modulus
+    pub modulus: String,
+    /// Key (modulus) length in bits
+    pub length: usize,
+}
+
+impl std::convert::TryFrom<openssl::rsa::Rsa<openssl::pkey::Public>> for RsaPubKeyInfo {
+    type Error = anyhow::Error;
+
+    fn try_from(value: openssl::rsa::Rsa<openssl::pkey::Public>) -> Result<Self, Self::Error> {
+        let modulus = value.n().to_hex_str()?.to_string();
+        let exponent = value.e().to_dec_str()?.to_string();
+        let length = value.size() as usize * 8;
+
+        Ok(Self {
+            path: None,
+            exponent,
+            modulus,
+            length,
+        })
+    }
+}