Merge pull request #183 from dajiaji/add-support-for-import-jwk

Add support for importKey('jwk').
dajiaji · Jul 17, 2023 · 04ffeaa · 04ffeaa
2 parents a50325b + 82aaa4d
commit 04ffeaa
Show file tree

Hide file tree

Showing 11 changed files with 1,058 additions and 58 deletions.
diff --git a/src/cipherSuite.ts b/src/cipherSuite.ts
@@ -242,8 +242,8 @@ export class CipherSuite {
    * @throws {@link DeserializeError}
    */
   public async importKey(
-    format: "raw",
-    key: ArrayBuffer,
+    format: "raw" | "jwk",
+    key: ArrayBuffer | JsonWebKey,
     isPublic = true,
   ): Promise<CryptoKey> {
     await this.setup();

diff --git a/src/interfaces/kemInterface.ts b/src/interfaces/kemInterface.ts
@@ -42,8 +42,8 @@ export interface KemInterface {
    * Imports a key for the KEM.
    */
   importKey(
-    format: "raw",
-    key: ArrayBuffer,
+    format: "raw" | "jwk",
+    key: ArrayBuffer | JsonWebKey,
     isPublic: boolean,
   ): Promise<CryptoKey>;
 

diff --git a/src/interfaces/kemPrimitives.ts b/src/interfaces/kemPrimitives.ts
@@ -4,8 +4,8 @@ export interface KemPrimitives {
   deserializePublicKey(key: ArrayBuffer): Promise<CryptoKey>;
 
   importKey(
-    format: "raw",
-    key: ArrayBuffer,
+    format: "raw" | "jwk",
+    key: ArrayBuffer | JsonWebKey,
     isPublic: boolean,
   ): Promise<CryptoKey>;
 

diff --git a/src/kems/dhkem.ts b/src/kems/dhkem.ts
@@ -64,8 +64,8 @@ export class Dhkem extends WebCrypto implements KemInterface {
   }
 
   public async importKey(
-    format: "raw",
-    key: ArrayBuffer,
+    format: "raw" | "jwk",
+    key: ArrayBuffer | JsonWebKey,
     isPublic: boolean,
   ): Promise<CryptoKey> {
     try {

diff --git a/src/kems/dhkemPrimitives/ec.ts b/src/kems/dhkemPrimitives/ec.ts
@@ -185,13 +185,24 @@ export class Ec implements KemPrimitives {
   }
 
   public async importKey(
-    format: "raw",
-    key: ArrayBuffer,
+    format: "raw" | "jwk",
+    key: ArrayBuffer | JsonWebKey,
     isPublic: boolean,
   ): Promise<CryptoKey> {
-    if (format !== "raw") {
-      throw new Error("Unsupported format");
+    if (format === "raw") {
+      return await this._importRawKey(key as ArrayBuffer, isPublic);
+    }
+    // jwk
+    if (key instanceof ArrayBuffer) {
+      throw new Error("Invalid jwk key format");
     }
+    return await this._importJWK(key as JsonWebKey, isPublic);
+  }
+
+  private async _importRawKey(
+    key: ArrayBuffer,
+    isPublic: boolean,
+  ): Promise<CryptoKey> {
     if (isPublic && key.byteLength !== this._nPk) {
       throw new Error("Invalid public key for the ciphersuite");
     }
@@ -201,7 +212,7 @@ export class Ec implements KemPrimitives {
     try {
       if (isPublic) {
         // return await this._api.importKey(format, key, this._alg, true, consts.KEM_USAGES);
-        return await this._api.importKey(format, key, this._alg, true, []);
+        return await this._api.importKey("raw", key, this._alg, true, []);
       }
       const k = new Uint8Array(key);
       const pkcs8Key = new Uint8Array(this._pkcs8AlgId.length + k.length);
@@ -219,6 +230,31 @@ export class Ec implements KemPrimitives {
     }
   }
 
+  private async _importJWK(
+    key: JsonWebKey,
+    isPublic: boolean,
+  ): Promise<CryptoKey> {
+    if (typeof key.crv === "undefined" || key.crv !== this._alg.namedCurve) {
+      throw new Error(`Invalid crv: ${key.crv}`);
+    }
+    if (isPublic) {
+      if (typeof key.d !== "undefined") {
+        throw new Error("Invalid key: `d` should not be set");
+      }
+      return await this._api.importKey("jwk", key, this._alg, true, []);
+    }
+    if (typeof key.d === "undefined") {
+      throw new Error("Invalid key: `d` not found");
+    }
+    return await this._api.importKey(
+      "jwk",
+      key,
+      this._alg,
+      true,
+      consts.KEM_USAGES,
+    );
+  }
+
   public async derivePublicKey(key: CryptoKey): Promise<CryptoKey> {
     const jwk = await this._api.exportKey("jwk", key);
     delete jwk["d"];

diff --git a/src/kems/dhkemPrimitives/x25519.ts b/src/kems/dhkemPrimitives/x25519.ts
@@ -6,6 +6,7 @@ import type { KdfInterface } from "../../interfaces/kdfInterface.ts";
 import { XCryptoKey } from "../../xCryptoKey.ts";
 
 import * as consts from "../../consts.ts";
+import { base64UrlToBytes } from "../../utils/misc.ts";
 
 const ALG_NAME = "X25519";
 
@@ -29,14 +30,18 @@ export class X25519 implements KemPrimitives {
   }
 
   public async importKey(
-    format: "raw",
-    key: ArrayBuffer,
+    format: "raw" | "jwk",
+    key: ArrayBuffer | JsonWebKey,
     isPublic: boolean,
   ): Promise<CryptoKey> {
-    if (format !== "raw") {
-      throw new Error("Unsupported format");
+    if (format === "raw") {
+      return await this._importRawKey(key as ArrayBuffer, isPublic);
+    }
+    // jwk
+    if (key instanceof ArrayBuffer) {
+      throw new Error("Invalid jwk key format");
     }
-    return await this._importKey(key, isPublic);
+    return await this._importJWK(key as JsonWebKey, isPublic);
   }
 
   public async derivePublicKey(key: CryptoKey): Promise<CryptoKey> {
@@ -89,7 +94,10 @@ export class X25519 implements KemPrimitives {
     });
   }
 
-  private _importKey(key: ArrayBuffer, isPublic: boolean): Promise<CryptoKey> {
+  private _importRawKey(
+    key: ArrayBuffer,
+    isPublic: boolean,
+  ): Promise<CryptoKey> {
     return new Promise((resolve, reject) => {
       if (isPublic && key.byteLength !== this._nPk) {
         reject(new Error("Invalid public key for the ciphersuite"));
@@ -107,6 +115,43 @@ export class X25519 implements KemPrimitives {
     });
   }
 
+  private _importJWK(key: JsonWebKey, isPublic: boolean): Promise<CryptoKey> {
+    return new Promise((resolve, reject) => {
+      if (typeof key.kty === "undefined" || key.kty !== "OKP") {
+        reject(new Error(`Invalid kty: ${key.kty}`));
+      }
+      if (typeof key.crv === "undefined" || key.crv !== "X25519") {
+        reject(new Error(`Invalid crv: ${key.crv}`));
+      }
+      if (isPublic) {
+        if (typeof key.d !== "undefined") {
+          reject(new Error("Invalid key: `d` should not be set"));
+        }
+        if (typeof key.x === "undefined") {
+          reject(new Error("Invalid key: `x` not found"));
+        }
+        resolve(
+          new XCryptoKey(
+            ALG_NAME,
+            base64UrlToBytes(key.x as string),
+            "public",
+          ),
+        );
+      } else {
+        if (typeof key.d !== "string") {
+          reject(new Error("Invalid key: `d` not found"));
+        }
+        resolve(
+          new XCryptoKey(
+            ALG_NAME,
+            base64UrlToBytes(key.d as string),
+            "private",
+          ),
+        );
+      }
+    });
+  }
+
   private _derivePublicKey(k: XCryptoKey): Promise<CryptoKey> {
     return new Promise((resolve) => {
       const pk = x25519.getPublicKey(k.key);

diff --git a/src/kems/dhkemPrimitives/x448.ts b/src/kems/dhkemPrimitives/x448.ts
@@ -6,6 +6,7 @@ import type { KdfInterface } from "../../interfaces/kdfInterface.ts";
 import { XCryptoKey } from "../../xCryptoKey.ts";
 
 import * as consts from "../../consts.ts";
+import { base64UrlToBytes } from "../../utils/misc.ts";
 
 const ALG_NAME = "X448";
 
@@ -29,14 +30,18 @@ export class X448 implements KemPrimitives {
   }
 
   public async importKey(
-    format: "raw",
-    key: ArrayBuffer,
+    format: "raw" | "jwk",
+    key: ArrayBuffer | JsonWebKey,
     isPublic: boolean,
   ): Promise<CryptoKey> {
-    if (format !== "raw") {
-      throw new Error("Unsupported format");
+    if (format === "raw") {
+      return await this._importRawKey(key as ArrayBuffer, isPublic);
+    }
+    // jwk
+    if (key instanceof ArrayBuffer) {
+      throw new Error("Invalid jwk key format");
     }
-    return await this._importKey(key, isPublic);
+    return await this._importJWK(key as JsonWebKey, isPublic);
   }
 
   public async derivePublicKey(key: CryptoKey): Promise<CryptoKey> {
@@ -89,7 +94,10 @@ export class X448 implements KemPrimitives {
     });
   }
 
-  private _importKey(key: ArrayBuffer, isPublic: boolean): Promise<CryptoKey> {
+  private _importRawKey(
+    key: ArrayBuffer,
+    isPublic: boolean,
+  ): Promise<CryptoKey> {
     return new Promise((resolve, reject) => {
       if (isPublic && key.byteLength !== this._nPk) {
         reject(new Error("Invalid public key for the ciphersuite"));
@@ -107,6 +115,43 @@ export class X448 implements KemPrimitives {
     });
   }
 
+  private _importJWK(key: JsonWebKey, isPublic: boolean): Promise<CryptoKey> {
+    return new Promise((resolve, reject) => {
+      if (key.kty !== "OKP") {
+        reject(new Error(`Invalid kty: ${key.kty}`));
+      }
+      if (key.crv !== "X448") {
+        reject(new Error(`Invalid crv: ${key.crv}`));
+      }
+      if (isPublic) {
+        if (typeof key.d !== "undefined") {
+          reject(new Error("Invalid key: `d` should not be set"));
+        }
+        if (typeof key.x !== "string") {
+          reject(new Error("Invalid key: `x` not found"));
+        }
+        resolve(
+          new XCryptoKey(
+            ALG_NAME,
+            base64UrlToBytes(key.x as string),
+            "public",
+          ),
+        );
+      } else {
+        if (typeof key.d !== "string") {
+          reject(new Error("Invalid key: `d` not found"));
+        }
+        resolve(
+          new XCryptoKey(
+            ALG_NAME,
+            base64UrlToBytes(key.d as string),
+            "private",
+          ),
+        );
+      }
+    });
+  }
+
   private _derivePublicKey(k: XCryptoKey): Promise<CryptoKey> {
     return new Promise((resolve) => {
       const pk = x448.getPublicKey(k.key);

diff --git a/src/utils/misc.ts b/src/utils/misc.ts
@@ -101,6 +101,19 @@ export function hexToBytes(v: string): Uint8Array {
 /**
  * Converts bytes to hex string.
  */
-export function bytesToHex(v: Uint8Array) {
+export function bytesToHex(v: Uint8Array): string {
   return [...v].map((x) => x.toString(16).padStart(2, "0")).join("");
 }
+
+/**
+ * Decodes Base64Url-encoded data.
+ */
+export function base64UrlToBytes(v: string): Uint8Array {
+  const base64 = v.replace(/-/g, "+").replace(/_/g, "/");
+  const byteString = atob(base64);
+  const ret = new Uint8Array(byteString.length);
+  for (let i = 0; i < byteString.length; i++) {
+    ret[i] = byteString.charCodeAt(i);
+  }
+  return ret;
+}
diff --git a/src/xCryptoKey.ts b/src/xCryptoKey.ts
@@ -11,5 +11,8 @@ export class XCryptoKey implements CryptoKey {
     this.key = key;
     this.type = type;
     this.algorithm = { name: name };
+    if (type === "public") {
+      this.usages = [];
+    }
   }
 }