使用ECDSA密钥时获取已签名的X509

我正在尝试签署一些X509证书。我的根私钥是ecdsa secp384r1。我在使用弹跳城堡。似乎在生成证书签名时,使用的签名类无法理解我的ECDSA密钥。

生成的代码如下:

    X509V3CertificateGenerator v3CertGen = new X509V3CertificateGenerator();
    v3CertGen.setSerialNumber(BigInteger.valueOf(serialNumber));
    v3CertGen.setIssuerDN(issuerPrincipal);
    v3CertGen.setNotBefore(notBefore);
    v3CertGen.setNotAfter(notAfter);
    v3CertGen.setSubjectDN(subjectDN);
    v3CertGen.setPublicKey(publicKey);
    v3CertGen.setSignatureAlgorithm(CERT_SIGNATURE_ALGORITHM); // this is ECDSAWITHSHA1
    X509Certificate cert = v3CertGen.generate(privateKey, BOUNCY_CASTLE_PROVIDER); // "BC"

其输出为:

java.security.InvalidKeyException: can't identify DSA private key.
    at org.bouncycastle.jce.provider.DSAUtil.generatePrivateKeyParameter(Unknown Source)
    at org.bouncycastle.jce.provider.JDKDSASigner.engineInitSign(Unknown Source)
    at java.security.Signature.initSign(Signature.java:480)
    at org.bouncycastle.x509.X509Util.calculateSignature(Unknown Source)
    at org.bouncycastle.x509.X509V3CertificateGenerator.generate(Unknown Source)
    at org.bouncycastle.x509.X509V3CertificateGenerator.generate(Unknown Source)
    at com.snip.utils.CertificateUtility.generateAndSignCertificate(CertificateUtility.java:147)

通过阅读bouncycastle源代码,我跟踪了这个问题,并用以下代码片段进行了重现:

Signature sig = Signature.getInstance(CERT_SIGNATURE_ALGORITHM, BOUNCY_CASTLE_PROVIDER);
System.out.println(sig.getAlgorithm());
System.out.println(sig.toString());
System.out.println(sig.getClass().getName());
try
{
    sig.initSign(privateKey);
    System.out.println(sig.toString());
} catch (Exception e) {
    e.printStackTrace();
}

产生输出:

SHA1withECDSA
Signature object: SHA1withECDSA<not initialized>
org.bouncycastle.jce.provider.JDKDSASigner$ecDSA
java.security.InvalidKeyException: can't identify DSA private key.
        at org.bouncycastle.jce.provider.DSAUtil.generatePrivateKeyParameter(Unknown Source)
        at org.bouncycastle.jce.provider.JDKDSASigner.engineInitSign(Unknown Source)
        at java.security.Signature.initSign(Signature.java:480)
        at com.snip.utils.CertificateUtility.<init>(CertificateUtility.java:99)

问题是我在这一点上完全迷路了。我不知道如何让证书生成器给我一个签名的证书。有人知道我做错了什么吗?