Added change password in pdf snippet

UsesCases/EncryptDecrypt/passwordModify.js

@@ -0,0 +1,57 @@
+import credentials from "../../../Credentials/credentials.json"  with { type: "json" };    // json-file in this format: { "id": "*****", "key": "*******" }
+import fs from 'node:fs/promises';
+import path from 'node:path';
+import { PdfApi } from "../../src/api/api.js";
+
+const configParams = {
+    LOCAL_FOLDER: "C:\\Samples\\",
+    PDF_DOCUMENT_NAME: "sample_encrypted.pdf",
+    LOCAL_RESULT_DOCUMENT_NAME: "change_password_output_sample.pdf",
+    DOCUMENT_PASSWORD: "Owner-Password",
+    NEW_USER_PASSWORD: "NEW-User-Password",
+    NEW_OWNER_PASSWORD: "NEW-Owner-Password",
+};
+
+const pdfApi = new PdfApi(credentials.id, credentials.key);
+
+const pdfEncoder = {
+    async uploadDocument () {
+        const fileNamePath = path.join(configParams.LOCAL_FOLDER, configParams.PDF_DOCUMENT_NAME);
+        const pdfFileData = await fs.readFile(fileNamePath);
+        await pdfApi.uploadFile(configParams.PDF_DOCUMENT_NAME, pdfFileData)
+            .then(() => console.log("File: '" + configParams.PDF_DOCUMENT_NAME +"' successfully uploaded."));
+    },
+
+    async downloadResult() {
+        const changedPdfData = await pdfApi.downloadFile(configParams.PDF_DOCUMENT_NAME);
+        const filePath = path.join(configParams.LOCAL_FOLDER, configParams.LOCAL_RESULT_DOCUMENT_NAME);
+        await fs.writeFile(filePath, changedPdfData.body);
+        console.log("Downloaded: " + filePath);
+    },
+
+    async change_passwords() {
+        const password_encoded = btoa(configParams.DOCUMENT_PASSWORD);
+        const new_user_password_encoded = btoa(configParams.NEW_USER_PASSWORD);
+        const new_owner_password_encoded = btoa(configParams.NEW_OWNER_PASSWORD);
+
+        const response = await pdfApi.postChangePasswordDocumentInStorage(configParams.PDF_DOCUMENT_NAME, password_encoded, new_user_password_encoded, new_owner_password_encoded);
+
+        if (response.body.code == 200)
+            console.log("change_passwords(): Password in document #'" + configParams.PDF_DOCUMENT_NAME + "' successfully changed.")
+        else
+            throw new Error("change_passwords(): Failed to decrypt document #'" + configParams.PDF_DOCUMENT_NAME + "'. Response code: {" + response.code + "}")
+    },
+
+}
+
+async function main() {
+    try {
+        await pdfEncoder.uploadDocument();
+        await pdfEncoder.change_passwords();
+        await pdfEncoder.downloadResult();
+    } catch (error) {
+        console.error("Error:", error.message);
+    }
+}
+
+main();