初始化环境文件

node_modules/@aws-crypto/supports-web-crypto/src/supportsWebCrypto.ts

@@ -0,0 +1,76 @@
+type SubtleCryptoMethod =
+  | "decrypt"
+  | "digest"
+  | "encrypt"
+  | "exportKey"
+  | "generateKey"
+  | "importKey"
+  | "sign"
+  | "verify";
+
+const subtleCryptoMethods: Array<SubtleCryptoMethod> = [
+  "decrypt",
+  "digest",
+  "encrypt",
+  "exportKey",
+  "generateKey",
+  "importKey",
+  "sign",
+  "verify"
+];
+
+export function supportsWebCrypto(window: Window): boolean {
+  if (
+    supportsSecureRandom(window) &&
+    typeof window.crypto.subtle === "object"
+  ) {
+    const { subtle } = window.crypto;
+
+    return supportsSubtleCrypto(subtle);
+  }
+
+  return false;
+}
+
+export function supportsSecureRandom(window: Window): boolean {
+  if (typeof window === "object" && typeof window.crypto === "object") {
+    const { getRandomValues } = window.crypto;
+
+    return typeof getRandomValues === "function";
+  }
+
+  return false;
+}
+
+export function supportsSubtleCrypto(subtle: SubtleCrypto) {
+  return (
+    subtle &&
+    subtleCryptoMethods.every(
+      methodName => typeof subtle[methodName] === "function"
+    )
+  );
+}
+
+export async function supportsZeroByteGCM(subtle: SubtleCrypto) {
+  if (!supportsSubtleCrypto(subtle)) return false;
+  try {
+    const key = await subtle.generateKey(
+      { name: "AES-GCM", length: 128 },
+      false,
+      ["encrypt"]
+    );
+    const zeroByteAuthTag = await subtle.encrypt(
+      {
+        name: "AES-GCM",
+        iv: new Uint8Array(Array(12)),
+        additionalData: new Uint8Array(Array(16)),
+        tagLength: 128
+      },
+      key,
+      new Uint8Array(0)
+    );
+    return zeroByteAuthTag.byteLength === 16;
+  } catch {
+    return false;
+  }
+}