电子合同订立系统

const { PDFDocument } = require('pdf-lib');
const fs = require('fs');

async function createAndSignContract() {
  // 创建一个新的PDF文档
  const pdfDoc = await PDFDocument.create();
  const page = pdfDoc.addPage();
  page.drawText('这是一个电子合同示例');

  // 保存PDF到文件
  const pdfBytes = await pdfDoc.save();
  fs.writeFileSync('contract.pdf', pdfBytes);

  // 签署PDF合同
  const signedPdfBytes = await signPdf(pdfBytes);
  fs.writeFileSync('signed_contract.pdf', signedPdfBytes);
}

async function signPdf(pdfBytes) {
  const pdfDoc = await PDFDocument.load(pdfBytes);
  const signatureField = pdfDoc.getForm().createSignature('signature');
  signatureField.setText('签署人姓名');

  // 使用私钥签署PDF
  const privateKey = fs.readFileSync('private_key.pem', 'utf8');
  const signature = await pdfDoc.saveSignature({
    type: 'PKCS#7',
    data: Buffer.from(privateKey),
  });

  signatureField.sign(signature);
  return await pdfDoc.save();
}

createAndSignContract();