用 JavaScript 通过 C++ 加密和解密 Excel 文件
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Microsoft Excel (97 - 365) 可以让您对电子表格进行加密和密码保护。它使用加密服务提供商（CSP）提供的算法，即一组具有不同属性的加密算法。默认的CSP是’Office 97/2000兼容’或’弱加密（XOR）'。选择适当的加密密钥长度很重要。有些CSP不支持超过40或56位。这被视为弱加密。对于强加密，需要最小128位的密钥长度。而且，Microsoft Windows中还包含提供强加密类型的CSP，例如 ‘Microsoft Strong Cryptographic Provider’。举例来说，128位加密是银行用于与其网上银行系统进行加密连接的加密级别。
Aspose.Cells允许您使用所需的加密类型对Microsoft Excel文件进行加密和密码保护。
使用Microsoft Excel
在Microsoft Excel（例如Microsoft Excel 2003）中设置文件加密设置:
- 从工具菜单中选择选项。会出现一个对话框。
- 选择安全性标签。
- 输入密码并点击高级
- 选择加密类型并确认密码。
用 Aspose.Cells for JavaScript 通过 C++ 加密 Excel 文件
以下示例演示了如何用 Aspose.Cells API 对Excel文件进行加密和密码保护。
<!DOCTYPE html>
<html>
<head>
<title>Aspose.Cells Example</title>
</head>
<body>
<h1>Aspose.Cells Example - Encrypt Workbook</h1>
<input type="file" id="fileInput" accept=".xls,.xlsx" />
<button id="runExample">Run Example</button>
<a id="downloadLink" style="display: none;">Download Result</a>
<div id="result"></div>
</body>
<script src="aspose.cells.js.min.js"></script>
<script type="text/javascript">
const { Workbook, SaveFormat } = AsposeCells;
AsposeCells.onReady({
license: "/lic/aspose.cells.enc",
fontPath: "/fonts/",
fontList: [
"arial.ttf",
"NotoSansSC-Regular.ttf"
]
}).then(() => {
console.log("Aspose.Cells initialized");
});
document.getElementById('runExample').addEventListener('click', async () => {
const fileInput = document.getElementById('fileInput');
if (!fileInput.files.length) {
document.getElementById('result').innerHTML = '<p style="color: red;">Please select an Excel file.</p>';
return;
}
const file = fileInput.files[0];
const arrayBuffer = await file.arrayBuffer();
// Instantiate a Workbook object by opening the uploaded excel file.
const workbook = new Workbook(new Uint8Array(arrayBuffer));
// Specify XOR encryption type.
workbook.encryptionOptions = { type: AsposeCells.EncryptionType.XOR, keyLength: 40 };
// Specify Strong Encryption type (RC4, Microsoft Strong Cryptographic Provider).
workbook.encryptionOptions = { type: AsposeCells.EncryptionType.StrongCryptographicProvider, keyLength: 128 };
// Password protect the file.
workbook.settings.password = "1234";
// Save the excel file.
const outputData = workbook.save(SaveFormat.Excel97To2003);
const blob = new Blob([outputData]);
const downloadLink = document.getElementById('downloadLink');
downloadLink.href = URL.createObjectURL(blob);
downloadLink.download = 'encryptedBook1.out.xls';
downloadLink.style.display = 'block';
downloadLink.textContent = 'Download Encrypted Excel File';
document.getElementById('result').innerHTML = '<p style="color: green;">Workbook encrypted and ready for download.</p>';
});
</script>
</html>
** 指定密码修改选项**
下面的示例显示了如何使用Aspose.Cells API为现有文件设置修改密码 Microsoft Excel选项。
<!DOCTYPE html>
<html>
<head>
<title>Aspose.Cells Example</title>
</head>
<body>
<h1>Specify Password To Modify Example</h1>
<input type="file" id="fileInput" accept=".xls,.xlsx,.csv" />
<button id="runExample">Run Example</button>
<a id="downloadLink" style="display: none;">Download Result</a>
<div id="result"></div>
</body>
<script src="aspose.cells.js.min.js"></script>
<script type="text/javascript">
const { Workbook, SaveFormat, Utils } = AsposeCells;
AsposeCells.onReady({
license: "/lic/aspose.cells.enc",
fontPath: "/fonts/",
fontList: [
"arial.ttf",
"NotoSansSC-Regular.ttf"
]
}).then(() => {
console.log("Aspose.Cells initialized");
});
document.getElementById('runExample').addEventListener('click', async () => {
const fileInput = document.getElementById('fileInput');
if (!fileInput.files.length) {
document.getElementById('result').innerHTML = '<p style="color: red;">Please select an Excel file.</p>';
return;
}
const file = fileInput.files[0];
const arrayBuffer = await file.arrayBuffer();
// Instantiating a Workbook object from the uploaded file
const workbook = new Workbook(new Uint8Array(arrayBuffer));
// Set the password for modification.
workbook.settings.writeProtection.password = "1234";
// Save the excel file.
const outputData = workbook.save(SaveFormat.Excel97To2003);
const blob = new Blob([outputData]);
const downloadLink = document.getElementById('downloadLink');
downloadLink.href = URL.createObjectURL(blob);
downloadLink.download = 'SpecifyPasswordToModifyOption.out.xls';
downloadLink.style.display = 'block';
downloadLink.textContent = 'Download Modified Excel File';
document.getElementById('result').innerHTML = '<p style="color: green;">Password-to-modify set successfully! Click the download link to get the modified file.</p>';
});
</script>
</html>
用 Aspose.Cells for JavaScript 通过 C++ 解密 Excel 文件
很容易用 Aspose.Cells API 打开受密码保护的Excel文件并解密，如以下代码所示：
<!DOCTYPE html>
<html>
<head>
<title>Aspose.Cells Example</title>
</head>
<body>
<h1>Open Encrypted Excel and Remove Password</h1>
<input type="file" id="fileInput" accept=".xls,.xlsx,.csv" />
<button id="runExample">Run Example</button>
<a id="downloadLink" style="display: none;">Download Result</a>
<div id="result"></div>
</body>
<script src="aspose.cells.js.min.js"></script>
<script type="text/javascript">
const { Workbook, LoadOptions, SaveFormat, Utils } = AsposeCells;
AsposeCells.onReady({
license: "/lic/aspose.cells.enc",
fontPath: "/fonts/",
fontList: [
"arial.ttf",
"NotoSansSC-Regular.ttf"
]
}).then(() => {
console.log("Aspose.Cells initialized");
});
document.getElementById('runExample').addEventListener('click', async () => {
const fileInput = document.getElementById('fileInput');
if (!fileInput.files.length) {
document.getElementById('result').innerHTML = '<p style="color: red;">Please select an encrypted Excel file.</p>';
return;
}
const file = fileInput.files[0];
const arrayBuffer = await file.arrayBuffer();
// Prepare load options with password to open encrypted file
const loadOptions = new LoadOptions();
loadOptions.password = "password";
// Instantiate workbook from uploaded file with load options
const workbook = new Workbook(new Uint8Array(arrayBuffer), loadOptions);
// Remove password from workbook settings
workbook.settings.password = null;
// Save the workbook and provide download link
const outputData = workbook.save(SaveFormat.Xlsx);
const blob = new Blob([outputData]);
const downloadLink = document.getElementById('downloadLink');
// Use original filename with suffix to indicate password removed
const originalName = file.name || 'output.xlsx';
const baseName = originalName.replace(/(\.xls[xm]?|\.csv)$/i, '') || 'output';
downloadLink.href = URL.createObjectURL(blob);
downloadLink.download = baseName + '.unlocked.xlsx';
downloadLink.style.display = 'block';
downloadLink.textContent = 'Download Unlocked Excel File';
document.getElementById('result').innerHTML = '<p style="color: green;">Password removed successfully! Click the download link to get the unlocked file.</p>';
});
</script>
</html>