public interface PDFDecrypter
decryptBuffer(String, PDFObject, ByteBuffer)
} should be used for decoding
streams, and decryptString(int, int, String)
for string values in
the PDF. It is possible for strings and streams to be encrypted with
different mechanisms, so the appropriate method must alwayus be used.Modifier and Type | Method and Description |
---|---|
java.nio.ByteBuffer |
decryptBuffer(java.lang.String cryptFilterName,
PDFObject streamObj,
java.nio.ByteBuffer streamBuf)
Decrypt a buffer of data
|
java.lang.String |
decryptString(int objNum,
int objGen,
java.lang.String inputBasicString)
Decrypt a
basic string . |
boolean |
isEncryptionPresent()
Determine whether this actually applies a decryption other than
identity decryption.
|
boolean |
isEncryptionPresent(java.lang.String cryptFilterName)
Determines whether decryption applies for a given crypt filter name
|
boolean |
isOwnerAuthorised()
Determine whether the password known by the decrypter indicates that
the user is the owner of the document.
|
java.nio.ByteBuffer decryptBuffer(java.lang.String cryptFilterName, PDFObject streamObj, java.nio.ByteBuffer streamBuf) throws PDFParseException
cryptFilterName
- the name of the crypt filter, if V4
encryption is being used, where individual crypt filters may
be specified for individual streams. If encryption is not using
V4 encryption (indicated by V=4 in the Encrypt dictionary) then
this must be null. Null may also be specified with V4 encryption
to indicate that the default filter should be used.streamObj
- the object whose stream is being decrypted. The
containing object's number and generation contribute to the key used for
stream encrypted with the document's default encryption, so this is
typically required. Should be null only if a cryptFilterName is
specified, as objects with specific stream filters use the general
document key, rather than a stream-specific key.streamBuf
- the buffer to decryptPDFParseException
- if the named crypt filter does not exist, or
if a crypt filter is named when named crypt filters are not supported.
Problems due to incorrect passwords are revealed prior to this point.java.lang.String decryptString(int objNum, int objGen, java.lang.String inputBasicString) throws PDFParseException
basic string
.objNum
- the object number of the containing objectobjGen
- the generation number of the containing objectinputBasicString
- the string to be decryptedPDFParseException
- if the named crypt filter does not exist, or
if a crypt filter is named when named crypt filters are not supported.
Problems due to incorrect passwords are revealed prior to this point.boolean isOwnerAuthorised()
isEncryptionPresent()
to determine whether any
permissions apply.boolean isEncryptionPresent()
boolean isEncryptionPresent(java.lang.String cryptFilterName)
cryptFilterName
- the crypt filter name