import org.spongycastle.cms.jcajce.JcaSignerInfoGeneratorBuilder; //导入依赖的package包/类
/**
 * Sign the given content using the private and public keys from the keySet, and return the encoded CMS (PKCS#7) data.
 * Use of direct signature and DER encoding produces a block that is verifiable by Android recovery programs.
 */
public static byte[] generate(KeySet keySet, byte[] content) {
    try {
        List certList = new ArrayList();
        CMSTypedData msg = new CMSProcessableByteArray(content);

        certList.add(keySet.getPublicKey());

        Store certs = new JcaCertStore(certList);

        CMSSignedDataGenerator gen = new CMSSignedDataGenerator();

        JcaContentSignerBuilder jcaContentSignerBuilder = new JcaContentSignerBuilder(keySet.getSignatureAlgorithm()).setProvider("SC");
        ContentSigner sha1Signer = jcaContentSignerBuilder.build(keySet.getPrivateKey());

        JcaDigestCalculatorProviderBuilder jcaDigestCalculatorProviderBuilder = new JcaDigestCalculatorProviderBuilder().setProvider("SC");
        DigestCalculatorProvider digestCalculatorProvider = jcaDigestCalculatorProviderBuilder.build();

        JcaSignerInfoGeneratorBuilder jcaSignerInfoGeneratorBuilder = new JcaSignerInfoGeneratorBuilder( digestCalculatorProvider);
        jcaSignerInfoGeneratorBuilder.setDirectSignature(true);
        SignerInfoGenerator signerInfoGenerator = jcaSignerInfoGeneratorBuilder.build(sha1Signer, keySet.getPublicKey());

        gen.addSignerInfoGenerator( signerInfoGenerator);

        gen.addCertificates(certs);

        CMSSignedData sigData = gen.generate(msg, false);
        return sigData.toASN1Structure().getEncoded("DER");

    } catch (Exception x) {
        throw new RuntimeException(x.getMessage(), x);
    }
}
 

import org.spongycastle.cms.jcajce.JcaSignerInfoGeneratorBuilder; //导入依赖的package包/类
@Override
public byte[] sign(InputStream content) throws IOException 
{
  CMSSignedDataGenerator gen = new CMSSignedDataGenerator();
  SignatureData input = new SignatureData(content);
  List<Certificate> certs = new ArrayList<Certificate>();
  for (int i = 0; i < chain.length; i ++) {
    certs.add(chain[i]);
  }

  try
  {
    Store certStore = new JcaCertStore(certs);

    Certificate cert = chain[0];
    org.spongycastle.asn1.x509.Certificate x509Cert =
      org.spongycastle.asn1.x509.Certificate.getInstance(ASN1Primitive.fromByteArray(cert.getEncoded()));

    ContentSigner sha256Signer = new JcaContentSignerBuilder("SHA256withRSA").build(privKey);
    gen.addSignerInfoGenerator(
             new JcaSignerInfoGeneratorBuilder(
             new JcaDigestCalculatorProviderBuilder().build())
             .build(sha256Signer, new X509CertificateHolder(x509Cert)));

    gen.addCertificates(certStore);
    CMSSignedData signedData = gen.generate(input, false);
    return signedData.getEncoded();
  }
  catch (Exception e)
  {
    e.printStackTrace();
  }
  throw new RuntimeException("Signing error, look at the stack trace");
}