Java tutorial
package org.bouncycastle.openssl; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.OutputStream; import org.bouncycastle.asn1.ASN1ObjectIdentifier; import org.bouncycastle.asn1.DERNull; import org.bouncycastle.asn1.cryptopro.CryptoProObjectIdentifiers; import org.bouncycastle.asn1.nist.NISTObjectIdentifiers; import org.bouncycastle.asn1.pkcs.EncryptedPrivateKeyInfo; import org.bouncycastle.asn1.pkcs.PKCSObjectIdentifiers; import org.bouncycastle.asn1.pkcs.PrivateKeyInfo; import org.bouncycastle.asn1.x509.AlgorithmIdentifier; import org.bouncycastle.operator.OutputEncryptor; import org.bouncycastle.util.io.pem.PemGenerationException; import org.bouncycastle.util.io.pem.PemObject; import org.bouncycastle.util.io.pem.PemObjectGenerator; public class PKCS8Generator implements PemObjectGenerator { public static final ASN1ObjectIdentifier AES_128_CBC = NISTObjectIdentifiers.id_aes128_CBC; public static final ASN1ObjectIdentifier AES_192_CBC = NISTObjectIdentifiers.id_aes192_CBC; public static final ASN1ObjectIdentifier AES_256_CBC = NISTObjectIdentifiers.id_aes256_CBC; public static final ASN1ObjectIdentifier DES3_CBC = PKCSObjectIdentifiers.des_EDE3_CBC; public static final ASN1ObjectIdentifier PBE_SHA1_RC4_128 = PKCSObjectIdentifiers.pbeWithSHAAnd128BitRC4; public static final ASN1ObjectIdentifier PBE_SHA1_RC4_40 = PKCSObjectIdentifiers.pbeWithSHAAnd40BitRC4; public static final ASN1ObjectIdentifier PBE_SHA1_3DES = PKCSObjectIdentifiers.pbeWithSHAAnd3_KeyTripleDES_CBC; public static final ASN1ObjectIdentifier PBE_SHA1_2DES = PKCSObjectIdentifiers.pbeWithSHAAnd2_KeyTripleDES_CBC; public static final ASN1ObjectIdentifier PBE_SHA1_RC2_128 = PKCSObjectIdentifiers.pbeWithSHAAnd128BitRC2_CBC; public static final ASN1ObjectIdentifier PBE_SHA1_RC2_40 = PKCSObjectIdentifiers.pbeWithSHAAnd40BitRC2_CBC; public static final AlgorithmIdentifier PRF_HMACSHA1 = new AlgorithmIdentifier( PKCSObjectIdentifiers.id_hmacWithSHA1, DERNull.INSTANCE); public static final AlgorithmIdentifier PRF_HMACSHA224 = new AlgorithmIdentifier( PKCSObjectIdentifiers.id_hmacWithSHA224, DERNull.INSTANCE); public static final AlgorithmIdentifier PRF_HMACSHA256 = new AlgorithmIdentifier( PKCSObjectIdentifiers.id_hmacWithSHA256, DERNull.INSTANCE); public static final AlgorithmIdentifier PRF_HMACSHA384 = new AlgorithmIdentifier( PKCSObjectIdentifiers.id_hmacWithSHA384, DERNull.INSTANCE); public static final AlgorithmIdentifier PRF_HMACSHA512 = new AlgorithmIdentifier( PKCSObjectIdentifiers.id_hmacWithSHA512, DERNull.INSTANCE); public static final AlgorithmIdentifier PRF_HMACGOST3411 = new AlgorithmIdentifier( CryptoProObjectIdentifiers.gostR3411Hmac, DERNull.INSTANCE); public static final AlgorithmIdentifier PRF_HMACSHA3_224 = new AlgorithmIdentifier( NISTObjectIdentifiers.id_hmacWithSHA3_224, DERNull.INSTANCE); public static final AlgorithmIdentifier PRF_HMACSHA3_256 = new AlgorithmIdentifier( NISTObjectIdentifiers.id_hmacWithSHA3_256, DERNull.INSTANCE); public static final AlgorithmIdentifier PRF_HMACSHA3_384 = new AlgorithmIdentifier( NISTObjectIdentifiers.id_hmacWithSHA3_384, DERNull.INSTANCE); public static final AlgorithmIdentifier PRF_HMACSHA3_512 = new AlgorithmIdentifier( NISTObjectIdentifiers.id_hmacWithSHA3_512, DERNull.INSTANCE); private PrivateKeyInfo key; private OutputEncryptor outputEncryptor; /** * Base constructor. */ public PKCS8Generator(PrivateKeyInfo key, OutputEncryptor outputEncryptor) { this.key = key; this.outputEncryptor = outputEncryptor; } public PemObject generate() throws PemGenerationException { if (outputEncryptor != null) { return generate(key, outputEncryptor); } else { return generate(key, null); } } private PemObject generate(PrivateKeyInfo key, OutputEncryptor encryptor) throws PemGenerationException { try { byte[] keyData = key.getEncoded(); if (encryptor == null) { return new PemObject("PRIVATE KEY", keyData); } ByteArrayOutputStream bOut = new ByteArrayOutputStream(); OutputStream cOut = encryptor.getOutputStream(bOut); cOut.write(key.getEncoded()); cOut.close(); EncryptedPrivateKeyInfo info = new EncryptedPrivateKeyInfo(encryptor.getAlgorithmIdentifier(), bOut.toByteArray()); return new PemObject("ENCRYPTED PRIVATE KEY", info.getEncoded()); } catch (IOException e) { throw new PemGenerationException("unable to process encoded key data: " + e.getMessage(), e); } } }