Merge pull request #185 from dajiaji/refactor-crypto-api-setting

Refactor Kem/Kdf/Aead algorithm constructor.

src/aeadKeys/aesGcmKey.ts

@@ -1,27 +1,29 @@
 import type { AeadKey } from "../interfaces/aeadKey.ts";
 
+import { Algorithm } from "../algorithm.ts";
 import { Aead } from "../identifiers.ts";
 import * as consts from "../consts.ts";
 
-export class AesGcmKey implements AeadKey {
+export class AesGcmKey extends Algorithm implements AeadKey {
   public readonly id: Aead = Aead.Aes128Gcm;
   public readonly keySize: number = 0;
   public readonly nonceSize: number = 0;
   public readonly tagSize: number = 0;
   private _rawKey: ArrayBuffer;
   private _key: CryptoKey | undefined = undefined;
-  private _api: SubtleCrypto;
+  // private _api: SubtleCrypto;
 
-  public constructor(key: ArrayBuffer, api: SubtleCrypto) {
+  public constructor(key: ArrayBuffer) {
+    super();
     this._rawKey = key;
-    this._api = api;
   }
 
   public async seal(
     iv: ArrayBuffer,
     data: ArrayBuffer,
     aad: ArrayBuffer,
   ): Promise<ArrayBuffer> {
+    this.checkInit();
     if (this._key === undefined) {
       this._key = await this.importKey(this._rawKey);
       (new Uint8Array(this._rawKey)).fill(0);
@@ -31,7 +33,11 @@ export class AesGcmKey implements AeadKey {
       iv: iv,
       additionalData: aad,
     };
-    const ct: ArrayBuffer = await this._api.encrypt(alg, this._key, data);
+    const ct: ArrayBuffer = await (this._api as SubtleCrypto).encrypt(
+      alg,
+      this._key,
+      data,
+    );
     return ct;
   }
 
@@ -40,6 +46,7 @@ export class AesGcmKey implements AeadKey {
     data: ArrayBuffer,
     aad: ArrayBuffer,
   ): Promise<ArrayBuffer> {
+    this.checkInit();
     if (this._key === undefined) {
       this._key = await this.importKey(this._rawKey);
       (new Uint8Array(this._rawKey)).fill(0);
@@ -49,12 +56,16 @@ export class AesGcmKey implements AeadKey {
       iv: iv,
       additionalData: aad,
     };
-    const pt: ArrayBuffer = await this._api.decrypt(alg, this._key, data);
+    const pt: ArrayBuffer = await (this._api as SubtleCrypto).decrypt(
+      alg,
+      this._key,
+      data,
+    );
     return pt;
   }
 
   private async importKey(key: ArrayBuffer): Promise<CryptoKey> {
-    return await this._api.importKey(
+    return await (this._api as SubtleCrypto).importKey(
       "raw",
       key,
       { name: "AES-GCM" },

src/aeadKeys/chacha20Poly1305Key.ts

@@ -1,17 +1,18 @@
 import { chacha20_poly1305 } from "npm:@noble/[email protected]/chacha";
 
+import { Algorithm } from "../algorithm.ts";
 import type { AeadKey } from "../interfaces/aeadKey.ts";
-
 import { Aead } from "../identifiers.ts";
 
-export class Chacha20Poly1305Key implements AeadKey {
+export class Chacha20Poly1305Key extends Algorithm implements AeadKey {
   public readonly id: Aead = Aead.Chacha20Poly1305;
   public readonly keySize: number = 32;
   public readonly nonceSize: number = 12;
   public readonly tagSize: number = 16;
   private _key: Uint8Array;
 
   public constructor(key: ArrayBuffer) {
+    super();
     this._key = new Uint8Array(key);
   }
 

src/algorithm.ts

@@ -0,0 +1,36 @@
+import * as consts from "./consts.ts";
+
+export class AlgorithmBase {
+  protected _api: SubtleCrypto | undefined = undefined;
+
+  constructor() {}
+
+  protected checkInit(): void {
+    if (typeof this._api === "undefined") {
+      throw new Error("Not initialized. Call init()");
+    }
+  }
+}
+
+export class Algorithm extends AlgorithmBase {
+  constructor() {
+    super();
+  }
+
+  public init(api: SubtleCrypto): void {
+    this._api = api;
+  }
+}
+
+export class KdfAlgorithm extends AlgorithmBase {
+  protected _suiteId: Uint8Array = consts.EMPTY;
+
+  constructor() {
+    super();
+  }
+
+  public init(api: SubtleCrypto, suiteId: Uint8Array): void {
+    this._api = api;
+    this._suiteId = suiteId;
+  }
+}

src/cipherSuite.ts

@@ -194,7 +194,9 @@ export class CipherSuite {
    */
   public async createAeadKey(key: ArrayBuffer): Promise<AeadKey> {
     await this.setup();
-    return createAeadKey(this.aead, key, this._api as SubtleCrypto);
+    const ret = createAeadKey(this.aead, key);
+    ret.init(this._api as SubtleCrypto);
+    return ret;
   }
 
   /**
@@ -534,31 +536,46 @@ export class CipherSuite {
   }
 
   private createKemContext(): KemInterface {
+    let ret: KemInterface;
     switch (this.kem) {
       case Kem.DhkemP256HkdfSha256:
-        return new DhkemP256HkdfSha256(this._api as SubtleCrypto);
+        ret = new DhkemP256HkdfSha256();
+        break;
       case Kem.DhkemP384HkdfSha384:
-        return new DhkemP384HkdfSha384(this._api as SubtleCrypto);
+        ret = new DhkemP384HkdfSha384();
+        break;
       case Kem.DhkemP521HkdfSha512:
-        return new DhkemP521HkdfSha512(this._api as SubtleCrypto);
+        ret = new DhkemP521HkdfSha512();
+        break;
       case Kem.DhkemX25519HkdfSha256:
-        return new DhkemX25519HkdfSha256(this._api as SubtleCrypto);
+        ret = new DhkemX25519HkdfSha256();
+        break;
       case Kem.DhkemX448HkdfSha512:
-        return new DhkemX448HkdfSha512(this._api as SubtleCrypto);
+        ret = new DhkemX448HkdfSha512();
+        break;
       default:
-        return new DhkemSecp256K1HkdfSha256(this._api as SubtleCrypto);
+        ret = new DhkemSecp256K1HkdfSha256();
+        break;
     }
+    ret.init(this._api as SubtleCrypto);
+    return ret;
   }
 
   private createKdfContext(): KdfInterface {
+    let ret: KdfInterface;
     switch (this.kdf) {
       case Kdf.HkdfSha256:
-        return new HkdfSha256(this._api as SubtleCrypto, this._suiteId);
+        ret = new HkdfSha256();
+        break;
       case Kdf.HkdfSha384:
-        return new HkdfSha384(this._api as SubtleCrypto, this._suiteId);
+        ret = new HkdfSha384();
+        break;
       default:
         // case Kdf.HkdfSha512:
-        return new HkdfSha512(this._api as SubtleCrypto, this._suiteId);
+        ret = new HkdfSha512();
+        break;
     }
+    ret.init(this._api as SubtleCrypto, this._suiteId);
+    return ret;
   }
 }

src/encryptionContext.ts

@@ -60,7 +60,8 @@ export class EncryptionContext extends ExporterContext {
         break;
     }
 
-    const key = createAeadKey(this._aead, params.key, this._api);
+    const key = createAeadKey(this._aead, params.key);
+    key.init(this._api);
 
     this._f = {
       key: key,
@@ -97,7 +98,8 @@ export class EncryptionContext extends ExporterContext {
         await this.export(nonceSeed, this._nN),
       );
       const key = await this.export(keySeed, this._nK);
-      this._r.key = createAeadKey(this._aead, key, this._api);
+      this._r.key = createAeadKey(this._aead, key);
+      this._r.key.init(this._api);
       this._r.seq = 0;
     } catch (e: unknown) {
       this._r.baseNonce = consts.EMPTY;
@@ -109,13 +111,12 @@ export class EncryptionContext extends ExporterContext {
 export function createAeadKey(
   aead: Aead,
   key: ArrayBuffer,
-  api: SubtleCrypto,
 ): AeadKey {
   switch (aead) {
     case Aead.Aes128Gcm:
-      return new Aes128GcmKey(key, api);
+      return new Aes128GcmKey(key);
     case Aead.Aes256Gcm:
-      return new Aes256GcmKey(key, api);
+      return new Aes256GcmKey(key);
     case Aead.Chacha20Poly1305:
       return new Chacha20Poly1305Key(key);
     default:

src/exporterContext.ts

@@ -2,13 +2,11 @@ import type { Encapsulator } from "./interfaces/encapsulator.ts";
 import type { EncryptionContextInterface } from "./interfaces/encryptionContextInterface.ts";
 import type { KdfInterface } from "./interfaces/kdfInterface.ts";
 
-import { WebCrypto } from "./webCrypto.ts";
-
 import * as consts from "./consts.ts";
 import * as errors from "./errors.ts";
 
-export class ExporterContext extends WebCrypto
-  implements EncryptionContextInterface {
+export class ExporterContext implements EncryptionContextInterface {
+  protected _api: SubtleCrypto;
   protected readonly exporterSecret: ArrayBuffer;
   private _kdf: KdfInterface;
 
@@ -17,7 +15,7 @@ export class ExporterContext extends WebCrypto
     kdf: KdfInterface,
     exporterSecret: ArrayBuffer,
   ) {
-    super(api);
+    this._api = api;
     this._kdf = kdf;
     this.exporterSecret = exporterSecret;
   }

src/interfaces/aeadKey.ts

@@ -13,6 +13,11 @@ export interface AeadKey {
   /** The length in bytes of an AEAD authentication tag (Nt). */
   readonly tagSize: number;
 
+  /**
+   * Initializes the key by setting the SubtleCrypto.
+   */
+  init(api: SubtleCrypto): void;
+
   /**
    * Encrypts data with initial vector and additional authenticated data.
    */

src/interfaces/kdfInterface.ts

@@ -16,6 +16,8 @@ export interface KdfInterface {
     len: number,
   ): Uint8Array;
 
+  init(api: SubtleCrypto, suiteId: Uint8Array): void;
+
   extract(
     salt: ArrayBuffer,
     ikm: ArrayBuffer,

src/interfaces/kemInterface.ts

@@ -18,6 +18,8 @@ export interface KemInterface {
   /** The length in bytes of an encoded private key for this KEM (Nsk). */
   readonly privateKeySize: number;
 
+  init(api: SubtleCrypto): void;
+
   /**
    * Generates a key pair.
    */

src/interfaces/kemPrimitives.ts

@@ -1,4 +1,6 @@
 export interface KemPrimitives {
+  init(api: SubtleCrypto): void;
+
   serializePublicKey(key: CryptoKey): Promise<ArrayBuffer>;
 
   deserializePublicKey(key: ArrayBuffer): Promise<CryptoKey>;