Initial Commit

packages/security-stack/crypto/crypto-rsa/src/keys/serialize-spki.ts

@@ -0,0 +1,22 @@
+import {
+    encodeBitString,
+    encodeNull,
+    encodeObjectIdentifier,
+    encodeSequence,
+} from "../asn1/writer.js";
+import type { RsaPublicKey } from "./keys.types.js";
+import { OID_RSA_ENCRYPTION } from "./oid.js";
+import { serializeRsaPublicKeyPkcs1 } from "./serialize-pkcs1-public.js";
+
+/**
+ * Serialise an `RsaPublicKey` to a DER-encoded `SubjectPublicKeyInfo`
+ * (RFC 5280 §4.1) wrapping a PKCS#1 `RSAPublicKey`.
+ */
+export function serializeRsaPublicKeySpki(key: RsaPublicKey): Uint8Array {
+    const algorithm = encodeSequence(
+        encodeObjectIdentifier(OID_RSA_ENCRYPTION),
+        encodeNull()
+    );
+    const subjectPublicKey = encodeBitString(serializeRsaPublicKeyPkcs1(key));
+    return encodeSequence(algorithm, subjectPublicKey);
+}