java - 如何从 Java 调用 CMD 创建 GnuPG-Keypair

Question

我正在尝试在 Java 中执行 gpg 命令来创建新的 key 对，但我没有从控制台得到答案。如果我尝试执行版本 gpg --version 的 gpg 命令或使用 gpg --list-key 检索 key 列表，我的代码可以正常工作。

我正在使用另一个 Stackoverflow-Question 的代码:

public void getKeyList(){
    try {

        Process gpgProcess = Runtime.getRuntime().exec("gpg --gen-key");

        BufferedReader gpgOutput = new BufferedReader(new InputStreamReader(gpgProcess.getInputStream()));
        BufferedWriter gpgInput = new BufferedWriter(new OutputStreamWriter(gpgProcess.getOutputStream()));
        BufferedReader gpgErrorOutput = new BufferedReader(new InputStreamReader(gpgProcess.getErrorStream()));

        boolean executing = true;

        while(executing){
              try {
                int exitValue = gpgProcess.exitValue();

                if (gpgErrorOutput.ready()){
                    String error = getStreamText(gpgErrorOutput);
                    System.err.println(error);
                }else if (gpgOutput.ready()){
                    System.out.println(getStreamText(gpgOutput));

                }
            } catch (Exception e){
              //The process is not yet ready to exit.  Take a break and try again.
                try {
                    Thread.sleep(100);
                } catch (InterruptedException e1) {
                    System.err.println("This thread has insomnia: " + e1.getMessage());
                }
            }
        }


    } catch (IOException e){
        e.printStackTrace();
    }

}

private String getStreamText(BufferedReader reader) throws IOException{
    StringBuilder result = new StringBuilder();
    try{
        while(reader.ready()){
            result.append(reader.readLine());
            if(reader.ready()){
                result.append("\n");
            }
        }
    }catch(IOException ioe){
        System.err.println("Error while reading the stream: " + ioe.getMessage());
        throw ioe;
    }
    return result.toString();
}

我还尝试过使用 ProcessBuilder 而不是 Runtime，但这不是解决方案。您是否知道如何解决这个问题，或者在 key 生成过程中完全无法与控制台交互？

Answer 1

gpg --genkey 是一个交互式调用，它等待输入，而您永远不会提供输入。两种可能的解决方案:

1. 请改用 bouncycaSTLe，它是 OpenPGP 的原生 Java 库。

2. 由于实现交互式 GnuPG session 将相当复杂且容易出错，因此您最好使用“实验功能”来批量生成 key 。来自man gpg:

   --gen-key
         Generate a new key pair. This command is normally only used
         interactively.
   
         There is an experimental feature which allows you to create
         keys  in  batch  mode.  See  the  file `doc/DETAILS' in the
         source distribution on how to use this.
   

   文件doc/DETAILS is also available online 。您要查找的部分称为“无人值守 key 生成”。它相当冗长，所以我没有在这里引用它，但这是文档中有关如何执行此操作的示例:

   $ cat >foo <<EOF
        %echo Generating a basic OpenPGP key
        Key-Type: DSA
        Key-Length: 1024
        Subkey-Type: ELG-E
        Subkey-Length: 1024
        Name-Real: Joe Tester
        Name-Comment: with stupid passphrase
        Name-Email: joe@foo.bar
        Expire-Date: 0
        Passphrase: abc
        %pubring foo.pub
        %secring foo.sec
        # Do a commit here, so that we can later print "done" :-)
        %commit
        %echo done
   EOF
   $ gpg --batch --gen-key foo