Deduplicate Issuer construction

Author: djc

rcgen/src/certificate.rs

@@ -143,13 +143,7 @@ impl CertificateParams {
 		issuer: &CertificateParams,
 		issuer_key: &impl SigningKey,
 	) -> Result<Certificate, Error> {
-		let issuer = Issuer {
-			distinguished_name: &issuer.distinguished_name,
-			key_identifier_method: &issuer.key_identifier_method,
-			key_usages: &issuer.key_usages,
-			key_pair: issuer_key,
-		};
-
+		let issuer = Issuer::new(&issuer, issuer_key);
 		Ok(Certificate {
 			der: self.serialize_der_with_signer(public_key, issuer)?,
 		})
@@ -160,13 +154,7 @@ impl CertificateParams {
 	/// The returned [`Certificate`] may be serialized using [`Certificate::der`] and
 	/// [`Certificate::pem`].
 	pub fn self_signed(&self, key_pair: &impl SigningKey) -> Result<Certificate, Error> {
-		let issuer = Issuer {
-			distinguished_name: &self.distinguished_name,
-			key_identifier_method: &self.key_identifier_method,
-			key_usages: &self.key_usages,
-			key_pair,
-		};
-
+		let issuer = Issuer::new(self, key_pair);
 		Ok(Certificate {
 			der: self.serialize_der_with_signer(key_pair, issuer)?,
 		})

rcgen/src/crl.rs

@@ -193,13 +193,7 @@ impl CertificateRevocationListParams {
 			return Err(Error::InvalidCrlNextUpdate);
 		}
 
-		let issuer = Issuer {
-			distinguished_name: &issuer.distinguished_name,
-			key_identifier_method: &issuer.key_identifier_method,
-			key_usages: &issuer.key_usages,
-			key_pair: issuer_key,
-		};
-
+		let issuer = Issuer::new(issuer, issuer_key);
 		if !issuer.key_usages.is_empty() && !issuer.key_usages.contains(&KeyUsagePurpose::CrlSign) {
 			return Err(Error::IssuerNotCrlSigner);
 		}

rcgen/src/csr.rs

@@ -205,13 +205,7 @@ impl CertificateSigningRequestParams {
 		issuer: &CertificateParams,
 		issuer_key: &impl SigningKey,
 	) -> Result<Certificate, Error> {
-		let issuer = Issuer {
-			distinguished_name: &issuer.distinguished_name,
-			key_identifier_method: &issuer.key_identifier_method,
-			key_usages: &issuer.key_usages,
-			key_pair: issuer_key,
-		};
-
+		let issuer = Issuer::new(issuer, issuer_key);
 		Ok(Certificate {
 			der: self
 				.params

rcgen/src/lib.rs

@@ -139,6 +139,17 @@ struct Issuer<'a, S> {
 	key_pair: &'a S,
 }
 
+impl<'a, S: SigningKey> Issuer<'a, S> {
+	fn new(params: &'a CertificateParams, key_pair: &'a S) -> Self {
+		Self {
+			distinguished_name: &params.distinguished_name,
+			key_identifier_method: &params.key_identifier_method,
+			key_usages: &params.key_usages,
+			key_pair,
+		}
+	}
+}
+
 // https://tools.ietf.org/html/rfc5280#section-4.1.1
 
 // Example certs usable as reference: