import org.spongycastle.cms.CMSEnvelopedDataGenerator; //导入依赖的package包/类
@NonNull
private InputStream getEncryptedInputStream(Context context, File tempFile,  ResourcePathManager.Resource publicKey)
{
    // Creating a CMS encrypted input stream that only recipients can decrypt
    CMSEnvelopedDataGenerator gen = new CMSEnvelopedDataGenerator();

    // Load bridge public key certificate from R.raw and add to recipients list
    try
    {
        CertificateFactory factory = new CertificateFactory();
        InputStream keyInputStream = publicKey.open(context);
        X509Certificate cert = (X509Certificate) factory.engineGenerateCertificate(
                keyInputStream);
        JceKeyTransRecipientInfoGenerator recipientInfoGenerator = new JceKeyTransRecipientInfoGenerator(
                cert).setProvider("SC");
        gen.addRecipientInfoGenerator(recipientInfoGenerator);

        // Generate encrypted input stream in AES-256-CBC format, output is DER, not S/MIME or PEM
        CMSProcessableFile content = new CMSProcessableFile(tempFile);
        OutputEncryptor encryptor = new JceCMSContentEncryptorBuilder(CMSAlgorithm.AES256_CBC).setProvider(
                "SC").build();
        CMSEnvelopedData envelopedData = gen.generate(content, encryptor);
        return new BufferedInputStream(new ByteArrayInputStream(envelopedData.getEncoded()));
    }
    catch(CertificateException | IOException | CMSException e)
    {
        throw new RuntimeException("Error encrypting with CMS", e);
    }
}
 

import org.spongycastle.cms.CMSEnvelopedDataGenerator; //导入依赖的package包/类
@NonNull
private InputStream getEncryptedInputStream(Context context, File tempFile, ResourcePathManager.Resource publicKey)
{
    // Creating a CMS encrypted input stream that only recipients can decrypt
    CMSEnvelopedDataGenerator gen = new CMSEnvelopedDataGenerator();

    // Load bridge public key certificate from R.raw and add to recipients list
    try
    {
        CertificateFactory factory = new CertificateFactory();
        InputStream keyInputStream = publicKey.open(context);
        X509Certificate cert = (X509Certificate) factory.engineGenerateCertificate(
                keyInputStream);
        JceKeyTransRecipientInfoGenerator recipientInfoGenerator = new JceKeyTransRecipientInfoGenerator(
                cert).setProvider("SC");
        gen.addRecipientInfoGenerator(recipientInfoGenerator);

        // Generate encrypted input stream in AES-256-CBC format, output is DER, not S/MIME or PEM
        CMSProcessableFile content = new CMSProcessableFile(tempFile);
        OutputEncryptor encryptor = new JceCMSContentEncryptorBuilder(CMSAlgorithm.AES256_CBC).setProvider(
                "SC").build();
        CMSEnvelopedData envelopedData = gen.generate(content, encryptor);
        return new BufferedInputStream(new ByteArrayInputStream(envelopedData.getEncoded()));
    }
    catch(CertificateException | IOException | CMSException e)
    {
        throw new RuntimeException("Error encrypting with CMS", e);
    }
}