tls指纹 java

TLS指纹是指TLS证书的指纹，可以用于验证证书的有效性和完整性。在Java中，可以使用javax.net.ssl包中的X509TrustManager接口来获取TLS证书的指纹。具体实现可以参考以下代码：

import java.security.MessageDigest;
import java.security.cert.CertificateEncodingException;
import java.security.cert.X509Certificate;

import javax.net.ssl.X509TrustManager;

public class MyTrustManager implements X509TrustManager {

    @Override
    public void checkClientTrusted(X509Certificate[] chain, String authType) {
        // do nothing
    }

    @Override
    public void checkServerTrusted(X509Certificate[] chain, String authType) throws CertificateException {
        for (X509Certificate cert : chain) {
            byte[] fingerprint = getCertificateSHA1Fingerprint(cert);
            System.out.println("TLS fingerprint: " + bytesToHex(fingerprint));
        }
    }

    @Override
    public X509Certificate[] getAcceptedIssuers() {
        return new X509Certificate[0];
    }

    private byte[] getCertificateSHA1Fingerprint(X509Certificate cert) throws CertificateEncodingException {
        MessageDigest md;
        try {
            md = MessageDigest.getInstance("SHA-1");
        } catch (NoSuchAlgorithmException e) {
            throw new CertificateEncodingException("SHA-1 not supported");
        }
        byte[] der = cert.getEncoded();        md.update(der);
        return md.digest();
    }

    private String bytesToHex(byte[] bytes) {
        StringBuilder sb = new StringBuilder();
        for (byte b : bytes) {
            sb.append(String.format("%02x", b));
        }
        return sb.toString();
    }
}