js base64加密文件

// 编码文件为 Base64
function encodeFileToBase64(file) {
    return new Promise((resolve, reject) => {
        const reader = new FileReader();
        reader.readAsDataURL(file);
        reader.onload = () => resolve(reader.result);
        reader.onerror = error => reject(error);
    });
}

// 解码 Base64 数据为文件
function decodeBase64ToFile(base64Data, fileName) {
    const byteCharacters = atob(base64Data.split(',')[1]);
    const byteNumbers = new Array(byteCharacters.length);
    for (let i = 0; i < byteCharacters.length; i++) {
        byteNumbers[i] = byteCharacters.charCodeAt(i);
    }
    const byteArray = new Uint8Array(byteNumbers);
    const blob = new Blob([byteArray], {type: 'application/octet-stream'});
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = fileName;
    document.body.appendChild(a);
    a.click();
    document.body.removeChild(a);
    URL.revokeObjectURL(url);
}

// 使用示例
const fileInput = document.querySelector('input[type="file"]');
fileInput.addEventListener('change', async (event) => {
    const file = event.target.files[0];
    try {
        const base64Data = await encodeFileToBase64(file);
        console.log('Base64 Data:', base64Data);
        decodeBase64ToFile(base64Data, 'decoded_file');
    } catch (error) {
        console.error('Error:', error);
    }
});