Merge pull request #468 from dajiaji/hybridkem-x-wing-refine-import-k…

…ey-support hybridkem-x-wing: refine import key support.
dajiaji · Nov 7, 2024 · e55aada · e55aada
2 parents aba1430 + 58e5abe
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diff --git a/packages/hybridkem-x-wing/README.md b/packages/hybridkem-x-wing/README.md
@@ -16,44 +16,52 @@ Documentation: [jsr.io](https://jsr.io/@hpke/hybridkem-x-wing/doc) |
 
 </div>
 
+An example of use:
+
 ```ts
+import { Aes256Gcm, CipherSuite, HkdfSha256 } from "@hpke/core";
+import { XWing } from "@hpke/hybridkem-x-wing";
+
 async function doHpke() {
   const suite = new CipherSuite({
     kem: new XWing(),
     kdf: new HkdfSha256(),
     aead: new Aes256Gcm(),
   });
 
-  // NOTE: The following support for JWKs with the AKP key type is experimental. Please be aware that the specifications are subject to change without notice.
-  const jwkPkR = {
+  // NOTE: The following support for JWKs with the AKP key type is experimental.
+  // Please be aware that the specifications are subject to change without notice.
+  const jwkPub = {
     kty: "AKP",
     kid: "01",
     alg: "X-Wing",
     pub:
       "4iNrNajCSzmxCqEyOpapGaLO2IQAYzp7BxMXE_wUsrWxnPw9pfoaksSfJVE-D9MNaxYRyauWNdcIZyekt9IdNCROZpac8Vs7KnhTKfYbCWsnfqA3ODR5prVW3nIx_kt_qcmsJMBpmgAYpSU0AbrPqQXKgWVz5WotLgZ-m3KHUzuhOpN97bMfpEus7UB2mSNhADSuMeYZoXAkUZmzxcOYZIWf4bTJcXoHwwSVvfuYoKACzPVsEobO9QQd7ePETPFr9WLHRIUYAms9i5lAaAq9OKFXX9J7WNoGO_rDLDnDCGk3TAXBrrGJi2swPMaL5FU0buCvaZY2IkoUjKKuoQRjERxwn2m2nHDOhTh0ZpjExgqa7wAwx5JM7sQqXTaBb1RerhMpNGCzrLN-oOE9cOSqeGhto5ioOXwI6vloghE_5Pe61NpAsFAeHHU-_nMFPIcBToZhwzCZr-i-3kFKWxqifYOSs-Ex6acMEFWHgkDK0PQNX-PN-FI26tl-KpdEg2OygIyq_VFs0lBSxcNiVDwlF-Ss0OYOwHFjAJtkJfwyJ3rO5xwkurU-2fKedMZqCjVklVmY12uWqai1DRY1pNemfrQt9WRNMwRXKTqAQvU8x6aSiPF-1Vgn6Cso6CZlqGoU-9lmReyoFywET4O8DYwLTIYmmFYxyoevgpBo8TWJY8szNmTKSCdjujs7sghXf5umrGLCX3ZZJ0O2S-UZMXcUy0ECy3svmiWytPBhXeMd7NnKVQJtbaC2URGxb-Uv7tikh-FERiptupNyj1ALb_xJ5RVWnvJf7Rev9SBQc2glNSWGD1i-O-YclkYEpqyBTmk1WWQCpSCkZws9KEMYhmWT0VpLsBw14-WH7gxn0ogNbyQH-3pwcSuDjeuWxde_K0S89gOMy-M_vPUaVKWE_pAIPJHHptQ9T7FfSMYML9ZuCoqtStZOXEK7iHfA6-wrXjh8ipiP3CO-ueFsh1d4HgoUmcYeE4wh8hbCnQdpeYccqmlCuvwJBUS-6ZtUsWy5qaNk1iRtn0LM5TxmtZxFyPmukpmnXRUYDDyVIVGpG3oQdyQp3Ey65vzGIvqAGMY0OfiQYwuZKNtrt_lDiuQGXtNNc9SG8_UvkPCAfciN_djHKOlU8aw1wGwADOQaBYJYDju1e2cpcokKxeeYjnhQZXEW8bV9CAmq7ewL7eGuFIFIMRxvfjFzRuUYn7jNY1uYb4wL3SdkHFhLd4s6kRqAvhyWkquOG7sSg5VzzOGd8YO0WDW7tVBS-fxmoWeO8qNt6nhBHmyNYFAbTmBZLRNpipQ7UJGF25EuLqEL4GFxI2syfHFxYJTJZKaLAzd_UToFvNmcHzRlg7sFKXehChKt_HWANOVhfaTBJ2WF5XdOHzuZeLCdDpxE07yGFRxDqtGFcScXNAIjrDgdIRUKBClOl7sTu9ohtaGCttqWnhmn_QcnN_qOiApTwkKOPQSbfSGXQFKW3bNhkSp7z0gnztYR0Men2hBN3kMiCVM59kph1bsQj_C_TXgMrlCfsiwlaRQZP_c0kEJYEjfVIoKIJO4739B_sD8flC0uoXn-ci8GzAPeW2mFntsG7_OJsn3OWYRFcCFiI1k9S6MtmrrIzQSQQO9lNA",
     key_ops: [],
   };
-  const pkR = await suite.kem.importKey("jwk", jwkPkR, true);
-  const sender = await suite.createSenderContext({
-    recipientPublicKey: pkR,
-  });
+  const pk = await suite.kem.importKey("jwk", jwkPub, true);
+  // In addition to importing keys from external sources, you can also generate keys as follows:
+  //   const rkp = await suite.kem.generateKeyPair();
+  //   const rkp = await suite.kem.deriveKeyPair(random32bytesValue);
 
-  const jwkSkR = {
+  const sender = await suite.createSenderContext({ recipientPublicKey: pk });
+
+  const jwkPriv = {
     kty: "AKP",
     kid: "01",
     alg: "X-Wing",
     priv: "f5wrpOiPgn1hYEVQdgWFPtc7gJP277yI6xpurPpm7yY",
     key_ops: ["deriveBits"],
   };
-  const skR = await suite.kem.importKey("jwk", jwkSkR, false);
+  const sk = await suite.kem.importKey("jwk", jwkPriv, false);
   const recipient = await suite.createRecipientContext({
-    recipientKey: skR,
+    recipientKey: sk,
     enc: sender.enc,
   });
-  const ct = await sender.seal(
+  const encrypted = await sender.seal(
     new TextEncoder().encode("Hellow world!"),
   );
-  const pt = await recipient.open(ct);
+  const pt = await recipient.open(encrypted);
 
   // Hello world!
   console.log(new TextDecoder().decode(pt));

diff --git a/packages/hybridkem-x-wing/src/xWing.ts b/packages/hybridkem-x-wing/src/xWing.ts
@@ -218,13 +218,33 @@ export class XWing implements KemInterface {
   ): Promise<CryptoKey> {
     await this._setup();
     try {
-      if (format === "raw") {
-        return await this._importRawKey(key as ArrayBuffer, isPublic);
+      let ret: Uint8Array;
+      if (format === "jwk") {
+        if (key instanceof ArrayBuffer || key instanceof Uint8Array) {
+          throw new Error("Invalid jwk key format");
+        }
+        ret = await this._importJWK(key as JsonWebKey, isPublic);
+      } else {
+        if (key instanceof ArrayBuffer) {
+          ret = new Uint8Array(key);
+        } else if (key instanceof Uint8Array) {
+          ret = key;
+        } else {
+          throw new Error("Invalid key format");
+        }
+      }
+      if (isPublic && ret.byteLength !== this.publicKeySize) {
+        throw new Error("Invalid length of the key");
       }
-      if (key instanceof ArrayBuffer) {
-        throw new Error("Invalid jwk key format");
+      if (!isPublic && ret.byteLength !== this.privateKeySize) {
+        throw new Error("Invalid length of the key");
       }
-      return await this._importJWK(key as JsonWebKey, isPublic);
+      return new XCryptoKey(
+        ALG_NAME,
+        ret,
+        isPublic ? "public" : "private",
+        isPublic ? [] : KEM_USAGES,
+      );
     } catch (e: unknown) {
       throw new DeserializeError(e);
     }
@@ -406,32 +426,10 @@ export class XWing implements KemInterface {
     });
   }
 
-  private _importRawKey(
-    key: ArrayBuffer,
-    isPublic: boolean,
-  ): Promise<CryptoKey> {
-    return new Promise((resolve, reject) => {
-      if (isPublic && key.byteLength !== this.publicKeySize) {
-        reject(new Error("Invalid length of the key"));
-      }
-      if (!isPublic && key.byteLength !== this.privateKeySize) {
-        reject(new Error("Invalid length of the key"));
-      }
-      resolve(
-        new XCryptoKey(
-          ALG_NAME,
-          new Uint8Array(key),
-          isPublic ? "public" : "private",
-          isPublic ? [] : KEM_USAGES,
-        ),
-      );
-    });
-  }
-
   private _importJWK(
     key: JsonWebKeyExtended,
     isPublic: boolean,
-  ): Promise<CryptoKey> {
+  ): Promise<Uint8Array> {
     return new Promise((resolve, reject) => {
       if (typeof key.kty === "undefined" || key.kty !== "AKP") {
         reject(new Error(`Invalid kty: ${key.kty}`));
@@ -449,15 +447,7 @@ export class XWing implements KemInterface {
         ) {
           reject(new Error("Invalid key: `key_ops` should be ['deriveBits']"));
         }
-        resolve(
-          new XCryptoKey(
-            ALG_NAME,
-            base64UrlToBytes(key.priv as string),
-            "private",
-            KEM_USAGES,
-          ),
-        );
-        return;
+        resolve(base64UrlToBytes(key.priv as string));
       }
       if (typeof key.priv !== "undefined") {
         reject(new Error("Invalid key: `priv` should not be set"));
@@ -468,13 +458,7 @@ export class XWing implements KemInterface {
       if (typeof key.key_ops !== "undefined" && key.key_ops.length > 0) {
         reject(new Error("Invalid key: `key_ops` should not be set"));
       }
-      resolve(
-        new XCryptoKey(
-          ALG_NAME,
-          base64UrlToBytes(key.pub as string),
-          "public",
-        ),
-      );
+      resolve(base64UrlToBytes(key.pub as string));
     });
   }
 }