用Java将数字签名添加到PDF
时间: 2024-03-09 14:02:58 浏览: 13
要将数字签名添加到PDF,可以使用Java的iText库。以下是添加数字签名的基本步骤:
1. 导入iText库。
2. 设置密钥库和证书。
```java
KeyStore ks = KeyStore.getInstance(KeyStore.getDefaultType());
ks.load(new FileInputStream("path/to/keystore"), "keystorePassword".toCharArray());
String alias = (String) ks.aliases().nextElement();
PrivateKey privateKey = (PrivateKey) ks.getKey(alias, "keyPassword".toCharArray());
Certificate[] chain = ks.getCertificateChain(alias);
```
3. 创建PdfReader对象并打开文档。
```java
PdfReader reader = new PdfReader("path/to/pdf");
PdfStamper stamper = PdfStamper.createSignature(reader, outputStream, '\0');
PdfSignatureAppearance appearance = stamper.getSignatureAppearance();
```
4. 设置签名外观。
```java
appearance.setReason("Reason for signing");
appearance.setLocation("Location of signing");
appearance.setVisibleSignature(new Rectangle(36, 748, 144, 780), 1, "signature");
```
5. 创建数字签名。
```java
ExternalSignature es = new PrivateKeySignature(privateKey, "SHA-256", "BC");
ExternalDigest digest = new BouncyCastleDigest();
MakeSignature.signDetached(appearance, digest, es, chain, null, null, null, 0, MakeSignature.CryptoStandard.CMS);
```
6. 关闭文档和输出流。
```java
stamper.close();
outputStream.close();
```
以上步骤仅作为示例,具体实现可能因为证书类型、签名算法等不同而有所区别。