java 解析國密SM2算法證書

首先說明用Java自帶的解析x509證書類，是不能解析sm2算法的證書，執行會拋出異常。

用開源庫bouncycastle能夠解析、詳細代碼

private byte[] getCSPK(byte[] csCert)

    {

        InputStream inStream = new ByteArrayInputStream(csCert);

        ASN1Sequence seq = null;

        ASN1InputStream aIn;

        try

        {

            aIn = new ASN1InputStream(inStream);

            seq = (ASN1Sequence)aIn.readObject();

            X509CertificateStructure cert = new X509CertificateStructure(seq);

            cert.getVersion();

            ASN1Primitive publicKey = cert.getSubjectPublicKeyInfo().getPublicKey();

            byte[] encodedPublicKey = publicKey.getEncoded();

            byte[] eP = new byte[64];

            System.arraycopy(encodedPublicKey, 5, eP, 0, eP.length);

            return eP;

        }

        catch (Exception e)

        {

            // TODO Auto-generated catch block

            e.printStackTrace();

        }

        return null;

}

所須要的jar包： http://download.csdn.net/detail/a956959099/7631425