PEM:Privacy Enhanced Mail is a Base64 encoded DER certificate
PEM files are used to represent Certificate/PrivateKey in an understandable format. They have a distinct header and footer for every key, where the body is composed of Base64 encoded Key.
They are represented as shown below for (Certificate/PrivateKey/Certificate Signing Request/PublicKey)
Java Program to generate PEM files.
PEM files are used to represent Certificate/PrivateKey in an understandable format. They have a distinct header and footer for every key, where the body is composed of Base64 encoded Key.
They are represented as shown below for (Certificate/PrivateKey/Certificate Signing Request/PublicKey)
-----BEGIN RSA PRIVATE KEY----- MIICWwIBAAKBgQCpF26VoB9/Au3Ct/dBFW5kfXFU8IkK+G3CG4slkVX2mwBtvLyb mFAuQ3RXvmX6tZxeUgwN7m+pZH+Y94lgAIpvcnzBEh8FFxwu0jy17uw+4ler5Soy YRGV8TYOeQHqoHS44clTG28T2RYy9lkRqTIkkCyo5ViyD7GVQVUgjR31LQIDAQAB AoGAFmkioPYd9ol+1aXoQVoDzZHKqYVPxIJ0mZto78u5ZvvYLLMtFDo1tkv+aXq0 rWvQk7ewHVCSwBKvzqhQLscjkbZqBdhnkBsyDQTcTQ+0sf8RGDHhBz2A1gGrBFhB rWc9wGuk7CFHUCrUL0ZXBquMM1KCd/+Fdg2+OQzcoJd9/AECQQDkLdyiaG4Y/lFM i4wtIf9rNVP4a1jHcYk1Ll7wvymY+v0e9zNVqKbkHaZ4/tyvD3MzVXZCByJZoFu4 sCWRK9WBAkEAvbVF3E7jxrQNTNRqLyQW6v0cmNSCSUfDkYANRuO+d6xvvT2HgrYs SiL8h4qDLkbM/LTvf9lxb8vSlUSt/3ctrQJAP70767YmQx8PkMVOg/ECS21bJoK+ CwCBJnTsmm2b7hr2iCbflScGb6SEsznmZZR4Rrex0CH0C3tLA91YsSPAgQJAa1Wc 6UFZbpuAyu+EBJgOv3XmMDJMZNnNtQ0Wdf11TpCpyBCAE1yvQmL5LlcYUZ6NbI2S 1Gta2z4fL4VkTR5JIQJAQE6QBPguRRYLFyDa6db+QyeJ1iBHy3I8XvK9bem+Dsby Km2l2KzLk3IpIEniqjLcoCQzFd5jp8m5VfjMx1doQQ== -----END RSA PRIVATE KEY----- -----BEGIN PUBLIC KEY----- MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCpF26VoB9/Au3Ct/dBFW5kfXFU 8IkK+G3CG4slkVX2mwBtvLybmFAuQ3RXvmX6tZxeUgwN7m+pZH+Y94lgAIpvcnzB Eh8FFxwu0jy17uw+4ler5SoyYRGV8TYOeQHqoHS44clTG28T2RYy9lkRqTIkkCyo 5ViyD7GVQVUgjR31LQIDAQAB -----END PUBLIC KEY----- -----BEGIN CERTIFICATE----- MIIBmjCCAQMCBgFOkeZMojANBgkqhkiG9w0BAQsFADATMREwDwYDVQQDEwhSYXZp VGVqYTAeFw0xNTA3MTQxMzI3NDVaFw0xNTA2MjkyMTQ1NTZaMBMxETAPBgNVBAMT CFJhdmlUZWphMIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCpF26VoB9/Au3C t/dBFW5kfXFU8IkK+G3CG4slkVX2mwBtvLybmFAuQ3RXvmX6tZxeUgwN7m+pZH+Y 94lgAIpvcnzBEh8FFxwu0jy17uw+4ler5SoyYRGV8TYOeQHqoHS44clTG28T2RYy 9lkRqTIkkCyo5ViyD7GVQVUgjR31LQIDAQABMA0GCSqGSIb3DQEBCwUAA4GBAIh6 cNhWToRwhaJBykHXPqiaqPDA8n0xtq65dBiUQWOKeoXw0I7+LKUUzfHfb4wGZoLK W2rBnNCY1BtpasqtAkdZ/Q+keJQd9xBcPqnKGUEqxxX7omB7cKYuhw9C+rGn/K1J Ci1xlYBWuRsMd3A064fSHV0Adu+ru9YaWyS5+aLU -----END CERTIFICATE-----
Java Program to generate PEM files.
package bc;
import java.io.File;
import java.io.FileWriter;
import java.io.PrintWriter;
import java.math.BigInteger;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.SecureRandom;
import java.security.Security;
import java.security.cert.X509Certificate;
import java.util.Date;
import javax.security.auth.x500.X500Principal;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.bouncycastle.openssl.PEMWriter;
import org.bouncycastle.x509.X509V1CertificateGenerator;
public class PEMWrite {
public static void main(String[] args) throws Exception {
generateSelfSignedX509Certificate();
}
static {
// adds the Bouncy castle provider to java security
Security.addProvider(new BouncyCastleProvider());
}
/**
* Generate a self signed X509 certificate with Bouncy Castle.
*/
static void generateSelfSignedX509Certificate() throws Exception {
// yesterday
Date validityBeginDate = new Date(System.currentTimeMillis() - 24 * 60 * 60 * 1000);
// in 2 years
Date validityEndDate = new Date(System.currentTimeMillis() + 2 * 365 * 24 * 60 * 60 * 1000);
// GENERATE THE PUBLIC/PRIVATE RSA KEY PAIR
KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA", "BC");
keyPairGenerator.initialize(1024, new SecureRandom());
KeyPair keyPair = keyPairGenerator.generateKeyPair();
// GENERATE THE X509 CERTIFICATE
X509V1CertificateGenerator certGen = new X509V1CertificateGenerator();
X500Principal dnName = new X500Principal("CN=RaviTeja");
certGen.setSerialNumber(BigInteger.valueOf(System.currentTimeMillis()));
certGen.setSubjectDN(dnName);
certGen.setIssuerDN(dnName); // use the same
certGen.setNotBefore(validityBeginDate);
certGen.setNotAfter(validityEndDate);
certGen.setPublicKey(keyPair.getPublic());
certGen.setSignatureAlgorithm("SHA256WithRSAEncryption");
X509Certificate cert = certGen.generate(keyPair.getPrivate(), "BC");
System.out.println(cert);
// PEM format representing Certificate
PEMWriter pemWriter = new PEMWriter(new PrintWriter(System.out));
pemWriter.writeObject(cert);
pemWriter.flush();
//Loads Private Key as PEM format into private_key.pem file
File file = new File("private_key.pem");
PEMWriter pw1 = new PEMWriter(new FileWriter(file));
pw1.writeObject(keyPair.getPrivate());
pw1.flush();
pw1.close();
//PEM format representing PrivateKey
pemWriter.writeObject(keyPair.getPrivate());
pemWriter.flush();
//PEM format representing PublicKey
pemWriter.writeObject(keyPair.getPublic());
pemWriter.flush();
pemWriter.close();
}
}
