Package org.pgpainless.signature.cleartext_signatures

Interface MultiPassStrategy

  • All Known Implementing Classes:
    InMemoryMultiPassStrategy, WriteToFileMultiPassStrategy
    public interface MultiPassStrategy
    Since the CleartextSignatureProcessor needs to read the whole data twice in order to verify signatures, a strategy for how to cache the read data is required. Otherwise large data kept in memory could cause OutOfMemoryErrors or other issues. This is an Interface that describes a strategy to deal with the fact that detached signatures require multiple passes to do verification. This interface can be used to write the signed data stream out via getMessageOutputStream() and later get access to the data again via getMessageInputStream(). Thereby the detail where the data is being stored (memory, file, etc.) can be abstracted away.

    • Method Detail

      • getMessageOutputStream

        java.io.OutputStream getMessageOutputStream()
                                     throws java.io.IOException
        Provide an OutputStream into which the signed data can be read into.
        Returns:
        output stream
        Throws:
        java.io.IOException - io error

      • getMessageInputStream

        java.io.InputStream getMessageInputStream()
                                   throws java.io.IOException
        Provide an InputStream which contains the data that was previously written away in getMessageOutputStream(). As there may be multiple signatures that need to be processed, each call of this method MUST return a new InputStream.
        Returns:
        input stream
        Throws:
        java.io.IOException - io error

      • writeMessageToFile

        static MultiPassStrategy writeMessageToFile​(java.io.File file)
        Write the message content out to a file and re-read it to verify signatures. This strategy is best suited for larger messages (eg. plaintext signed files) which might not fit into memory. After the message has been processed completely, the messages content are available at the provided file.
        Parameters:
        file - target file
        Returns:
        strategy

      • keepMessageInMemory

        static InMemoryMultiPassStrategy keepMessageInMemory()
        Read the message content into memory. This strategy is best suited for small messages which fit into memory. After the message has been processed completely, the message content can be accessed by calling ByteArrayOutputStream.toByteArray() on getMessageOutputStream().
        Returns:
        strategy