Package org.docx4j.org.apache.poi.poifs.crypt

Class Decryptor

java.lang.Object
org.docx4j.org.apache.poi.poifs.crypt.Decryptor
All Implemented Interfaces:
GenericRecord
Direct Known Subclasses:
AgileDecryptor, BinaryRC4Decryptor, CryptoAPIDecryptor, StandardDecryptor, XORDecryptor
public abstract class Decryptor extends Object implements GenericRecord

  • Field Details

  • Constructor Details

    • Decryptor

      protected Decryptor()

    • Decryptor

      protected Decryptor(Decryptor other)

  • Method Details

    • getDataStream

      public abstract InputStream getDataStream(DirectoryNode dir) throws IOException, GeneralSecurityException
      Return a stream with decrypted data.

      Use getLength() to get the size of that data that can be safely read from the stream. Just reading to the end of the input stream is not sufficient because there are normally padding bytes that must be discarded

      Parameters:
      dir - the node to read from
      Returns:
      decrypted stream
      Throws:
      IOException
      GeneralSecurityException

    • getDataStream

      public InputStream getDataStream(InputStream stream, int size, int initialPos) throws IOException, GeneralSecurityException
      Wraps a stream for decryption

      As we are handling streams and don't know the total length beforehand, it's the callers duty to care for the length of the entries.

      Parameters:
      stream - the stream to be wrapped
      initialPos - initial/current byte position within the stream
      Returns:
      decrypted stream
      Throws:
      IOException
      GeneralSecurityException

    • setChunkSize

      public void setChunkSize(int chunkSize)
      Sets the chunk size of the data stream. Needs to be set before the data stream is requested. When not set, the implementation uses method specific default values
      Parameters:
      chunkSize - the chunk size, i.e. the block size with the same encryption key

    • initCipherForBlock

      public Cipher initCipherForBlock(Cipher cipher, int block) throws GeneralSecurityException
      Initializes a cipher object for a given block index for encryption
      Parameters:
      cipher - may be null, otherwise the given instance is reset to the new block index
      block - the block index, e.g. the persist/slide id (hslf)
      Returns:
      a new cipher object, if cipher was null, otherwise the reinitialized cipher
      Throws:
      GeneralSecurityException - if the cipher can't be initialized

    • verifyPassword

      public abstract boolean verifyPassword(String password) throws GeneralSecurityException
      Throws:
      GeneralSecurityException

    • getLength

      public abstract long getLength()
      Returns the length of the encrypted data that can be safely read with getDataStream(org.apache.poi.poifs.filesystem.DirectoryNode). Just reading to the end of the input stream is not sufficient because there are normally padding bytes that must be discarded

      The length variable is initialized in getDataStream(org.apache.poi.poifs.filesystem.DirectoryNode), an attempt to call getLength() prior to getDataStream() will result in IllegalStateException.

      Returns:
      length of the encrypted data
      Throws:
      IllegalStateException - if getDataStream(org.apache.poi.poifs.filesystem.DirectoryNode) was not called

    • getInstance

      public static Decryptor getInstance(EncryptionInfo info)

    • getDataStream

      public InputStream getDataStream(POIFSFileSystem fs) throws IOException, GeneralSecurityException
      Throws:
      IOException
      GeneralSecurityException

    • getVerifier

      public byte[] getVerifier()

    • getSecretKey

      public SecretKey getSecretKey()

    • getIntegrityHmacKey

      public byte[] getIntegrityHmacKey()

    • getIntegrityHmacValue

      public byte[] getIntegrityHmacValue()

    • setSecretKey

      protected void setSecretKey(SecretKey secretKey)

    • setVerifier

      protected void setVerifier(byte[] verifier)

    • setIntegrityHmacKey

      protected void setIntegrityHmacKey(byte[] integrityHmacKey)

    • setIntegrityHmacValue

      protected void setIntegrityHmacValue(byte[] integrityHmacValue)

    • getBlockSizeInBytes

      protected int getBlockSizeInBytes()

    • getKeySizeInBytes

      protected int getKeySizeInBytes()

    • getEncryptionInfo

      public EncryptionInfo getEncryptionInfo()

    • setEncryptionInfo

      public void setEncryptionInfo(EncryptionInfo encryptionInfo)

    • copy

      public abstract Decryptor copy()

    • getGenericProperties

      public Map<String,Supplier<?>> getGenericProperties()
      Specified by:
      getGenericProperties in interface GenericRecord