从密钥库中的文件读取公钥

嗨，我想使用Java代码从KeyStore中提取公钥

我正在创建一个密钥库

keytool -genkey -alias mykeystore -keyalg RSA -keystore mykeystore.jks -keysize 2048 

并将公众导出到另一个文件中

 keytool -export -alias mykeystore -keystore mykeystore.jks -rfc -file publickey.cert 

如何使用Java代码从keystore或publickey.cert文件获取公钥字符串？

谢谢。

UPDATE

 public static void main(String[] args) { try { FileInputStream is = new FileInputStream("/home/myuser/my-keystore/mykeystore.jks"); KeyStore keystore = KeyStore.getInstance(KeyStore.getDefaultType()); String password = "myuserpass"; char[] passwd = password.toCharArray(); keystore.load(is, passwd); String alias = "mykeystore"; Key key = keystore.getKey(alias, passwd); if (key instanceof PrivateKey) { // Get certificate of public key Certificate cert = keystore.getCertificate(alias); // Get public key PublicKey publicKey = cert.getPublicKey(); String publicKeyString = Base64.encodeBase64String(publicKey .getEncoded()); System.out.println(publicKeyString); } } catch (Exception e) { e.printStackTrace(); } } 

那就是给予喜欢

 MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAiG2FjSuXrraYuh0TyRNiUvVCyaFlb7VY9AFIMSDdcY0JgNF0c4YVQxYxUCbYzmkLZD/rrYMe/8nxkWV0TMz2Y7GnvichjtWHL1ui58uC0+RtFMkYJ+ftwt9qBy9hvb/rVFTsvT5/b6CQXD8a6bFveMUluQZISLCV7i11XYzp81+w6M7+2fJAwezIJnIrgwv1K9YDjWaToaNXe7hnzzy0s8AdkjTk197+hg8dRfbvkr8XAddNsEMPeUA5iY+5VEpRNI925ZT/dxnaABA0z6i4JbVjeLl8r7ySG9R/2w/j2G+/YSRQc9BmRHPa0tBgH7wvQM+WRwD9WmST+5qeBIfH3QIDAQAB 

当我做cat publickey.cert ，它显示了这一点

 -----BEGIN CERTIFICATE----- MIIDgTCCAmmgAwIBAgIEf7XoMDANBgkqhkiG9w0BAQsFADBxMQswCQYDVQQGEwJJTjESMBAGA1UE CBMJS2FybmF0YWthMRIwEAYDVQQHEwlCYW5nYWxvcmUxEjAQBgNVBAoTCU5ldHNjaXR1czESMBAG A1UECxMJTmV0c2NpdHVzMRIwEAYDVQQDEwlOZXRzY2l0dXMwHhcNMTQxMTAzMDkyNTM3WhcNMTUw MjAxMDkyNTM3WjBxMQswCQYDVQQGEwJJTjESMBAGA1UECBMJS2FybmF0YWthMRIwEAYDVQQHEwlC YW5nYWxvcmUxEjAQBgNVBAoTCU5ldHNjaXR1czESMBAGA1UECxMJTmV0c2NpdHVzMRIwEAYDVQQD EwlOZXRzY2l0dXMwggEiMA0GCSqGSIb3DQEBAQUAA4IBDwAwggEKAoIBAQCIbYWNK5eutpi6HRPJ E2JS9ULJoWVvtVj0AUgxIN1xjQmA0XRzhhVDFjFQJtjOaQtkP+utgx7/yfGRZXRMzPZjsae+JyGO 1YcvW6Lny4LT5G0UyRgn5+3C32oHL2G9v+tUVOy9Pn9voJBcPxrpsW94xSW5BkhIsJXuLXVdjOnz X7Dozv7Z8kDB7MgmciuDC/Ur1gONZpOho1d7uGfPPLSzwB2SNOTX3v6GDx1F9u+SvxcB102wQw95 QDmJj7lUSlE0j3bllP93GdoAEDTPqLgltWN4uXyvvJIb1H/bD+PYb79hJFBz0GZEc9rS0GAfvC9A z5ZHAP1aZJP7mp4Eh8fdAgMBAAGjITAfMB0GA1UdDgQWBBSvgDYtI/NGP8Y0EvsCHASjmr/PmzAN BgkqhkiG9w0BAQsFAAOCAQEACefje/dhmzEkBoA6OV934WtGXcBQNcb+9/qBGevUBG1cNJIyJddi dea2gFUB1rx/WffTrJyiOCApV8wXG+zmGm6YJenKnGG9sIQtOTibhs3ll7UN4S0n9xsD+1y7YD1c DNm9lI/3aFn1WUwPc3T4+RXE6XqkDB3geIvLUXaFUi+Y59XiLPHvk61kcopCGeoweX5yWVZ2Njp/ UUJIxQ6Ni3GvfPlxCxWtRe1MDAkhfT6/aAUr37lxtupHibzm9EAJdUEmAFHMhxkNCJiRDsasAiQ8 7V5uBI3ucdSwh+gPaW8KoWlJpv5SGlAkwzq0lSrxyq2ukkC6ciPeKhUvWtHaPg== -----END CERTIFICATE----- 

它们的键是不同的，即使长度也不同。 为什么？

Answer 1

只需谷歌搜索您的问题就可以找到解决方案。

java2s.com的示例：

 import java.io.FileInputStream; import java.security.Key; import java.security.KeyPair; import java.security.KeyStore; import java.security.PrivateKey; import java.security.PublicKey; import java.security.cert.Certificate; public class Main { public static void main(String[] argv) throws Exception { FileInputStream is = new FileInputStream("your.keystore"); KeyStore keystore = KeyStore.getInstance(KeyStore.getDefaultType()); keystore.load(is, "my-keystore-password".toCharArray()); String alias = "myalias"; Key key = keystore.getKey(alias, "password".toCharArray()); if (key instanceof PrivateKey) { // Get certificate of public key Certificate cert = keystore.getCertificate(alias); // Get public key PublicKey publicKey = cert.getPublicKey(); // Return a key pair new KeyPair(publicKey, (PrivateKey) key); } } } 

也可以看看：

• http://www.java2s.com/Code/Java/Security/RetrievingaKeyPairfromaKeyStore.htm
• 如何从我们创建的密钥库中检索我的公钥和私钥

更新：

有关该问题的其他信息，请参阅注释。

Answer 2

如果它只是您想要的公钥字符串， publickey.cert容易获取publickey.cert文件，因为它是纯文本文件。 假设您拥有该文件的完整路径（例如“/home/users/iprogrammer/publickey.cert”或“D：\ MyDocuments \ publickey.cert”），您可以执行以下操作：

 public String getPublicKeyString( Path path ) throws IOException { byte[] fileBytes = Files.readAllBytes(Paths.get(path)); return new String( fileBytes, "US-ASCII" ); } 

这将为您提供整个文件，包括-----BEGIN CERTIFICATE-----和-----END CERTIFICATE----- 。

获得完整个文件后，可以使用BouncyCastle库打开它：

  PEMParser pemParser = new PEMParser(new StringReader(certPEMData)); Object parsedObj = pemParser.readObject(); System.out.println("PemParser returned: " + parsedObj); if (parsedObj instanceof X509CertificateHolder) { X509CertificateHolder x509CertificateHolder = (X509CertificateHolder) parsedObj; return x509CertificateHolder.getSubjectPublicKeyInfo().getPublicKeyData().getString(); } else { throw new RuntimeException("The parsed object was not an X509CertificateHolder."); } 

Answer 3

尝试这个：

 import java.security.KeyStore; import java.security.KeyStoreException; import java.security.NoSuchAlgorithmException; import java.security.cert.Certificate; import java.security.cert.CertificateException; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.IOException; import java.util.Enumeration; import java.security.PublicKey; import java.util.Base64; //===================== try { File file = new File("C:\\Program Files (x86)\\keyStoreFilehere.kstr"); FileInputStream is = new FileInputStream(file); KeyStore keystore = KeyStore.getInstance(KeyStore.getDefaultType()); String password = "password"; keystore.load(is, password.toCharArray()); Enumeration enumeration = keystore.aliases(); while(enumeration.hasMoreElements()) { String alias = (String)enumeration.nextElement(); Certificate certificate = keystore.getCertificate(alias); PublicKey publicKey = keystore.getCertificate(alias).getPublicKey(); byte[] encodedCertKey = certificate.getEncoded(); byte[] encodedPublicKey = publicKey.getEncoded(); String b64PublicKey = Base64.getMimeEncoder().encodeToString(encodedPublicKey); String b64CertKey = Base64.getMimeEncoder().encodeToString(encodedCertKey); String publicKeyString = "-----BEGIN CERTIFICATE-----\n" + b64PublicKey + "\n-----END CERTIFICATE-----"; String certKeyString = "-----BEGIN CERTIFICATE-----\n" + b64CertKey + "\n-----END CERTIFICATE-----"; System.out.println(publicKeyString); System.out.println(certKeyString); } } catch (CertificateException | NoSuchAlgorithmException | KeyStoreException | IOException e) { e.printStackTrace(); } 

Answer 4

成功导出后，您可以从密钥库中获取，

通过KeyPair(publicKey, (PrivateKey) key)

一个例子 ，

  FileInputStream is = new FileInputStream("publickey.cert"); KeyStore keystore = KeyStore.getInstance(KeyStore.getDefaultType()); keystore.load(is, "my-keystore-password".toCharArray()); String alias = "myalias"; Key key = keystore.getKey(alias, "password".toCharArray()); if (key instanceof PrivateKey) { // Get certificate of public key Certificate cert = keystore.getCertificate(alias); // Get public key PublicKey publicKey = cert.getPublicKey(); // Return a key pair new KeyPair(publicKey, (PrivateKey) key); } } 

将返回新的键值对。

还可以在此处阅读类似的post从Keystore获取私钥

Answer 5

如果您想要PublicKey的字符串版本：

String publicKeyString value = "-----BEGIN PUBLIC KEY-----\n" + new String(Base64.encode(publicKey.getEncoded())) + "\n-----END PUBLIC KEY-----";

Answer 6

第一个基础64仅包含密钥

 Base64.encodeBase64String(publicKey.getEncoded()) 

第二个基础64包含整个公共证书

 Base64.encodeBase64String(cert.getEncoded())