Monkeybread Software - DynaPDF Manual

DynaPDF Manual - Page 218

Function Reference

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Password encodings

On Windows, Linux, and Unix operating systems passwords are converted to the code page 1252

(WinAnsi) and then to PDFDoc encoding. On Mac OS X or iOS passwords are converted to

MacRoman and then to PDFDoc encoding. PDFDoc encoding is a superset of WinAnsi and

MacRoman encoding that ensures that a password can be correctly interpreted on these operating

systems.

UTF-8 Passwords

All Ansi functions accept UTF-8 Unicode strings as input if the flag gfAnsiStringIsUTF8 is set (see

SetGStateFlags() for further information). However, only the encryption handlers klAES256 and

klAESRev6 support Unicode passwords.

For every other encryption handler DynaPDF converts the string to the code page 1252 on

Windows, Linux, or Unix operating systems, or to MacRoman on Mac OS X and iOS.

Encryption flags

As mentioned earlier only specific flag combinations are allowed to use depending on the

encryption filter. We want now determine how the 40 bit encryption flags can be used in

comparison to the Acrobat input mask. The encryption mask in Acrobat 9 looks as follows:

The combo box at "Printing Allowed" sets the flag rsPrint if printing should be disabled. The combo

box at "Changes Allowed" sets the following flag combinations:

• None:

rsModify + rsAddObj

• Commenting, Filling in form fields and signing: rsModify

• Page layout, filling in form fields:

No additional flags!

• Any except extracting pages:

No additional flags!

As you can see above the third and forth options set the same flags. The forth value is just a

duplicate of the third with another description.

The check box "Enable copying of text, images, and other…" sets the flag rsCopyObj if it is unchecked!

Multiple flags must be combined with a binary or operator.

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