Pull out pbkdf2Sha512Subtle

packages/crypto/src/pbkdf2.spec.ts

@@ -1,6 +1,7 @@
 import { fromHex, toAscii, toUtf8 } from "@cosmjs/encoding";
+import { assert } from "@cosmjs/utils";
 
-import { pbkdf2Sha512 } from "./pbkdf2";
+import { getSubtle, pbkdf2Sha512, pbkdf2Sha512Subtle } from "./pbkdf2";
 
 interface TestVector {
   secret: Uint8Array;
@@ -115,7 +116,26 @@ describe("pbkdf2", () => {
       for (const [index, test] of brycxTests.entries()) {
         const { secret, salt, iterations, keylen, expected } = test;
         const hash = await pbkdf2Sha512(secret, salt, iterations, keylen);
-        expect(hash).withContext(`Index ${index}`).toEqual(expected);
+        expect(hash).withContext(`brycx tests index ${index}`).toEqual(expected);
+      }
+    });
+  });
+
+  describe("pbkdf2Sha512Subtle", () => {
+    it("works", async () => {
+      const subtle = await getSubtle();
+      assert(subtle);
+
+      {
+        const { secret, salt, iterations, keylen, expected } = botanTest;
+        const hash = await pbkdf2Sha512Subtle(subtle, secret, salt, iterations, keylen);
+        expect(hash).toEqual(expected);
+      }
+
+      for (const [index, test] of brycxTests.entries()) {
+        const { secret, salt, iterations, keylen, expected } = test;
+        const hash = await pbkdf2Sha512Subtle(subtle, secret, salt, iterations, keylen);
+        expect(hash).withContext(`brycx tests index ${index}`).toEqual(expected);
       }
     });
   });

packages/crypto/src/pbkdf2.ts

@@ -1,4 +1,6 @@
-async function getSubtle(): Promise<any | undefined> {
+import { assert } from "@cosmjs/utils";
+
+export async function getSubtle(): Promise<any | undefined> {
   const g: any = globalThis;
   let subtle = g.crypto && g.crypto.subtle;
   if (!subtle) {
@@ -10,6 +12,35 @@ async function getSubtle(): Promise<any | undefined> {
   return subtle;
 }
 
+export async function pbkdf2Sha512Subtle(
+  // eslint-disable-next-line @typescript-eslint/explicit-module-boundary-types
+  subtle: any,
+  secret: Uint8Array,
+  salt: Uint8Array,
+  iterations: number,
+  keylen: number,
+): Promise<Uint8Array> {
+  assert(subtle, "Argument subtle is falsy");
+  assert(typeof subtle === "object", "Argument subtle is not of type object");
+  assert(typeof subtle.importKey === "function", "subtle.importKey is not a function");
+  assert(typeof subtle.deriveBits === "function", "subtle.deriveBits is not a function");
+
+  return subtle.importKey("raw", secret, { name: "PBKDF2" }, false, ["deriveBits"]).then((key: Uint8Array) =>
+    subtle
+      .deriveBits(
+        {
+          name: "PBKDF2",
+          salt: salt,
+          iterations: iterations,
+          hash: { name: "SHA-512" },
+        },
+        key,
+        keylen * 8,
+      )
+      .then((buffer: ArrayBuffer) => new Uint8Array(buffer)),
+  );
+}
+
 /**
  * A pbkdf2 implementation for BIP39. This is not exported at package level and thus a private API.
  */
@@ -21,22 +52,7 @@ export async function pbkdf2Sha512(
 ): Promise<Uint8Array> {
   const subtle = await getSubtle();
   if (subtle) {
-    return subtle
-      .importKey("raw", secret, { name: "PBKDF2" }, false, ["deriveBits"])
-      .then((key: Uint8Array) =>
-        subtle
-          .deriveBits(
-            {
-              name: "PBKDF2",
-              salt: salt,
-              iterations: iterations,
-              hash: { name: "SHA-512" },
-            },
-            key,
-            keylen * 8,
-          )
-          .then((buffer: ArrayBuffer) => new Uint8Array(buffer)),
-      );
+    return pbkdf2Sha512Subtle(subtle, secret, salt, iterations, keylen);
   } else {
     const module = await import("crypto");
     return new Promise((resolve, reject) => {