Java AlgorithmId.derEncode方法代码示例

import sun.security.x509.AlgorithmId; //导入方法依赖的package包/类
/**
 * Encode the contents of the outer-most ASN.1 SEQUENCE:
 *
 * <PRE>
 *  Certificate  ::=  SEQUENCE  {
 *      tbsCertificate       TBSCertificate,
 *      signatureAlgorithm   AlgorithmIdentifier,
 *      signatureValue       BIT STRING  }
 * </PRE>
 *
 * @param issuerCert The certificate of the issuing authority, or
 * {@code null} if the resulting certificate is self-signed.
 * @param issuerKey The private key of the issuing authority
 * @param signAlg The signature algorithm object
 *
 * @return The DER-encoded X.509 certificate
 *
 * @throws CertificateException If an error occurs during the
 * signing process.
 * @throws IOException if an encoding error occurs.
 */
private byte[] encodeTopLevel(X509Certificate issuerCert,
        PrivateKey issuerKey, AlgorithmId signAlg)
        throws CertificateException, IOException {
    DerOutputStream outerSeq = new DerOutputStream();
    DerOutputStream topLevelItems = new DerOutputStream();

    tbsCertBytes = encodeTbsCert(issuerCert, signAlg);
    topLevelItems.write(tbsCertBytes);
    try {
        signatureBytes = signCert(issuerKey, signAlg);
    } catch (GeneralSecurityException ge) {
        throw new CertificateException(ge);
    }
    signAlg.derEncode(topLevelItems);
    topLevelItems.putBitString(signatureBytes);
    outerSeq.write(DerValue.tag_Sequence, topLevelItems);

    return outerSeq.toByteArray();
}
 

import sun.security.x509.AlgorithmId; //导入方法依赖的package包/类
/**
 * Encode the bytes for the TBSCertificate structure:
 * <PRE>
 *  TBSCertificate  ::=  SEQUENCE  {
 *      version         [0]  EXPLICIT Version DEFAULT v1,
 *      serialNumber         CertificateSerialNumber,
 *      signature            AlgorithmIdentifier,
 *      issuer               Name,
 *      validity             Validity,
 *      subject              Name,
 *      subjectPublicKeyInfo SubjectPublicKeyInfo,
 *      issuerUniqueID  [1]  IMPLICIT UniqueIdentifier OPTIONAL,
 *                        -- If present, version MUST be v2 or v3
 *      subjectUniqueID [2]  IMPLICIT UniqueIdentifier OPTIONAL,
 *                        -- If present, version MUST be v2 or v3
 *      extensions      [3]  EXPLICIT Extensions OPTIONAL
 *                        -- If present, version MUST be v3
 *      }
 *
 * @param issuerCert The certificate of the issuing authority, or
 * {@code null} if the resulting certificate is self-signed.
 * @param signAlg The signature algorithm object
 *
 * @return The DER-encoded bytes for the TBSCertificate structure
 *
 * @throws IOException if an encoding error occurs.
 */
private byte[] encodeTbsCert(X509Certificate issuerCert,
        AlgorithmId signAlg) throws IOException {
    DerOutputStream tbsCertSeq = new DerOutputStream();
    DerOutputStream tbsCertItems = new DerOutputStream();

    // Hardcode to V3
    byte[] v3int = {0x02, 0x01, 0x02};
    tbsCertItems.write(DerValue.createTag(DerValue.TAG_CONTEXT, true,
            (byte)0), v3int);

    // Serial Number
    SerialNumber sn = new SerialNumber(serialNumber);
    sn.encode(tbsCertItems);

    // Algorithm ID
    signAlg.derEncode(tbsCertItems);

    // Issuer Name
    if (issuerCert != null) {
        tbsCertItems.write(
                issuerCert.getSubjectX500Principal().getEncoded());
    } else {
        // Self-signed
        tbsCertItems.write(subjectName.getEncoded());
    }

    // Validity period (set as UTCTime)
    DerOutputStream valSeq = new DerOutputStream();
    valSeq.putUTCTime(notBefore);
    valSeq.putUTCTime(notAfter);
    tbsCertItems.write(DerValue.tag_Sequence, valSeq);

    // Subject Name
    tbsCertItems.write(subjectName.getEncoded());

    // SubjectPublicKeyInfo
    tbsCertItems.write(publicKey.getEncoded());

    // TODO: Extensions!
    encodeExtensions(tbsCertItems);

    // Wrap it all up in a SEQUENCE and return the bytes
    tbsCertSeq.write(DerValue.tag_Sequence, tbsCertItems);
    return tbsCertSeq.toByteArray();
}