將PEM格式的字符串轉換爲java.security.cert.X509Certificate

如何從PEM格式的字符串創建java.security.cert.X509Certificate實例？ PEM格式的字符串是HTTP請求「SSL_CLIENT_CERT」標頭值。將PEM格式的字符串轉換爲java.security.cert.X509Certificate

答案： 基於mgaert的答案，這是我在斯卡拉寫道：

val cert = factory.generateCertificate(
    new ByteArrayInputStream(
     Base64.decodeBase64(
     cert.stripPrefix("-----BEGIN CERTIFICATE-----").stripSuffix("-----END CERTIFICATE-----") 
    ) 
    ).asInstanceOf[X509Certificate]

來源

2012-03-16 chunjef

沒有必要解碼它。直接支持PEM base64編碼格式，如[本答案]（http://stackoverflow.com/a/9739366/822870）。再次： CertificateFactory cFactory = CertificateFactory.getInstance（「X.509」）; X509Certificate cert =（X509Certificate）cFactory.generateCertificate（getInputStream（of_the_original_unmodified_certificate_file））; – 2015-05-21 15:08:28

似乎沒有必要去除前綴/後綴 – lznt 2017-10-18 22:27:42

解碼的Base64編碼到二進制，讀取某些InputStream它，然後嘗試

CertificateFactory cf = CertificateFactory.getInstance("X.509"); 
Certificate cert = cf.generateCertificate(is);

來源

2012-03-16 14:44:09 mgaert

我有一個類似的問題，我粘貼也在這裏的Java代碼，爲我工作，如果有人掛了它：

import java.util.Base64; 

public static X509Certificate parseCertificate(String _headerName, HttpServletRequest _request) throws CertificateException { 
    String certStr = _request.getHeader("x-clientcert"); 
    //before decoding we need to get rod off the prefix and suffix 
    byte [] decoded = Base64.getDecoder().decode(certStr.replaceAll(X509Factory.BEGIN_CERT, "").replaceAll(X509Factory.END_CERT, "")); 

    return (X509Certificate) CertificateFactory.getInstance("X.509").generateCertificate(new ByteArrayInputStream(decoded)); 
}

來源

2013-11-27 11:10:49 simonC

PEM格式化字符串轉換的步驟與（x509 - >字符串）發生方式相反。

樣品PEM格式的字符串：

-----BEGIN CERTIFICATE----- 
MIIEczCCA1ugAwIBAgIBADANBgkqhkiG9w0BAQQFAD..AkGA1UEBhMCR0Ix 
EzARBgNVBAgTClNvbWUtU3RhdGUxFDASBgNVBAoTC0..0EgTHRkMTcwNQYD 
VQQLEy5DbGFzcyAxIFB1YmxpYyBQcmltYXJ5IENlcn..XRpb24gQXV0aG9y 
aXR5MRQwEgYDVQQDEwtCZXN0IENBIEx0ZDAeFw0wMD..TUwMTZaFw0wMTAy 
MDQxOTUwMTZaMIGHMQswCQYDVQQGEwJHQjETMBEGA1..29tZS1TdGF0ZTEU 
MBIGA1UEChMLQmVzdCBDQSBMdGQxNzA1BgNVBAsTLk..DEgUHVibGljIFBy 
aW1hcnkgQ2VydGlmaWNhdGlvbiBBdXRob3JpdHkxFD..AMTC0Jlc3QgQ0Eg 
THRkMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCg..Tz2mr7SZiAMfQyu 
vBjM9OiJjRazXBZ1BjP5CE/Wm/Rr500PRK+Lh9x5eJ../ANBE0sTK0ZsDGM 
ak2m1g7oruI3dY3VHqIxFTz0Ta1d+NAjwnLe4nOb7/..k05ShhBrJGBKKxb 
8n104o/5p8HAsZPdzbFMIyNjJzBM2o5y5A13wiLitE..fyYkQzaxCw0Awzl 
kVHiIyCuaF4wj571pSzkv6sv+4IDMbT/XpCo8L6wTa..sh+etLD6FtTjYbb 
rvZ8RQM1tlKdoMHg2qxraAV++HNBYmNWs0duEdjUbJ..XI9TtnS4o1Ckj7P 
OfljiQIDAQABo4HnMIHkMB0GA1UdDgQWBBQ8urMCRL..5AkIp9NJHJw5TCB 
tAYDVR0jBIGsMIGpgBQ8urMCRLYYMHUKU5AkIp9NJH..aSBijCBhzELMAkG 
A1UEBhMCR0IxEzARBgNVBAgTClNvbWUtU3RhdGUxFD..AoTC0Jlc3QgQ0Eg 
THRkMTcwNQYDVQQLEy5DbGFzcyAxIFB1YmxpYyBQcm..ENlcnRpZmljYXRp 
b24gQXV0aG9yaXR5MRQwEgYDVQQDEwtCZXN0IENBIE..DAMBgNVHRMEBTAD 
AQH/MA0GCSqGSIb3DQEBBAUAA4IBAQC1uYBcsSncwA..DCsQer772C2ucpX 
xQUE/C0pWWm6gDkwd5D0DSMDJRqV/weoZ4wC6B73f5..bLhGYHaXJeSD6Kr 
XcoOwLdSaGmJYslLKZB3ZIDEp0wYTGhgteb6JFiTtn..sf2xdrYfPCiIB7g 
BMAV7Gzdc4VspS6ljrAhbiiawdBiQlQmsBeFz9JkF4..b3l8BoGN+qMa56Y 
It8una2gY4l2O//on88r5IWJlm1L0oA8e4fR2yrBHX..adsGeFKkyNrwGi/ 
7vQMfXdGsRrXNGRGnX+vWDZ3/zWI0joDtCkNnqEpVn..HoX 
-----END CERTIFICATE-----

步驟如下：

1. Remove headers from PEM formatted String 
Headers are : ---- BEGIN CERTIFICATE ----- and ----- END CERTIFICATE ------ 
2. Decode the rest of the part using Base64 to byte array 
3. Then you can use CertificateFactory to convert byte stream to x509Certificate object

示例代碼以上做（與PEM作家）：

/** 
    * Converts a PEM formatted String to a {@link X509Certificate} instance. 
    * 
    * @param pem PEM formatted String 
    * @return a X509Certificate instance 
    * @throws CertificateException 
    * @throws IOException 
    */ 
    public X509Certificate convertToX509Certificate(String pem) throws CertificateException, IOException { 
     X509Certificate cert = null; 
     StringReader reader = new StringReader(pem); 
     PEMReader pr = new PEMReader(reader); 
     cert = (X509Certificate)pr.readObject(); 
     return cert; 
    }

來源

2015-01-13 19:44:46

請注意，PEMReader是Bouncy Castle Crypto API的一部分，請參閱https://www.bouncycastle.org/。 @mgaert編寫的代碼無需外部庫。 – 2016-11-16 14:46:37

另一個樣品，

public static X509Certificate convertToX509Cert(String certificateString) throws CertificateException { 
    X509Certificate certificate = null; 
    CertificateFactory cf = null; 
    try { 
     if (certificateString != null && !certificateString.trim().isEmpty()) { 
      certificateString = certificateString.replace("-----BEGIN CERTIFICATE-----\n", "") 
        .replace("-----END CERTIFICATE-----", ""); // NEED FOR PEM FORMAT CERT STRING 
      byte[] certificateData = Base64.getDecoder().decode(certificateString); 
      cf = CertificateFactory.getInstance("X509"); 
      certificate = (X509Certificate) cf.generateCertificate(new ByteArrayInputStream(certificateData)); 
     } 
    } catch (CertificateException e) { 
     throw new CertificateException(e); 
    } 
    return certificate; 
}

來源

2017-04-18 06:24:02 Zeigeist

將PEM格式的字符串轉換爲java.security.cert.X509Certificate

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