feat & refactor: 支持app端签名的请求，支持右键操作书架书籍，逻辑大幅重构，更改默认的设备逻辑为自动注册，支持载入某些书籍内置的CSS、支持跳转正文注释等等

src/crypto/content.ts

@@ -0,0 +1,65 @@
+import { defaultConfig, type DeviceConfig } from "../config";
+import { b64decode, getSubtle, unhex } from ".";
+
+// 正文算法: AES/CBC/PKCS5Padding
+// 返回 string(xhtml/html) | 章节 JSON 对象 | undefined(解析失败)
+export async function decryptChapter(
+    encrypted: string,
+    config: DeviceConfig = defaultConfig,
+): Promise<string | unknown> {
+    if (!encrypted) {
+        throw new Error("Invalid encrypted chapter");
+    };
+    const buf = b64decode(encrypted);
+    const iv = buf.slice(0, 16);
+    const data = buf.slice(16);
+    const key = config.key_info?.key;
+    if (!key) {
+        throw new Error("Missing decrypt key")
+    }
+    const subtle = getSubtle();
+    const cryptoKey = await subtle.importKey(
+        "raw",
+        key,
+        { name: "AES-CBC" },
+        false,
+        ["decrypt"],
+    );
+    return subtle.decrypt(
+        { name: "AES-CBC", iv },
+        cryptoKey,
+        data,
+    ).then((decrypted) => {
+        const decoder = new TextDecoder();
+        const plain = decoder.decode(decrypted);
+        if (plain.trim().startsWith("<")) { // xhtml || html
+            return plain;
+        }
+        try {
+            return JSON.parse(plain); // mostly JSONObject
+        } catch (e: any) {
+            console.warn('Invalid chapter content: ', plain, e);
+            return undefined;
+        }
+    });
+}
+
+
+export async function decryptComicImage(image: ArrayBuffer, key: string /* hex */): Promise<ArrayBuffer> {
+    const subtle = getSubtle();
+    // AESGCM
+    const cryptoKey = await subtle.importKey(
+        "raw",
+        unhex(key),
+        { name: "AES-GCM" },
+        false,
+        ["decrypt"],
+    );
+    const iv = image.slice(0, 12);
+    const data = image.slice(12);
+    return await subtle.decrypt(
+        { name: "AES-GCM", iv },
+        cryptoKey,
+        data,
+    );
+}