Valid Characters for PDF 1.6 User...

Hi,

What character set is considered as a valid for user password in Pdf 1.6? I know Pdf 1,6 accepts only single byte characters in user password? Is there any set of valid password characters? I searched Pdf 1,6 spec and adobe forums, but couldn't find anything related to this.

Thanks

Venki

Valid Characters for PDF 1.6 User...

Hi Venki,

You can use any use any high or low bit ASCII character and even some Unicode characters, but you have to be careful because the Password fields are OS based, and the MAC will prevent you from adding some characters via the Character Pallet that you can use on Windows. You could end up locking out the Mac users.

Steve

Valid Characters for PDF 1.6 User...

Thanks Steve!

What if I restrict the input user password character set to only ASCII characters? Do you expect any problems while opening the encrypted documents on Mac or Windows?

Thanks

Venki

Hi Venki,

Low-bit ASCII will be problem free, but I think that some of the high-bit ASCII characters get interpreted differently between the two platforms. I'm just not sure which ones. Even in Acrobat 9 where the allowable Unicode set is much more robust there are still some characters that the MAC won't allow. I even filed a bug with my counterparts at Apple that if you try to use a Cyrillic keyboard the OS will automatically switch you to a Latin (Roman) based keyboard. They sent the bug back noting that it works ''as designed''. They are intentionally restricting passwords to Roman characters.

Steve

As defined in the PDF Reference, the allowed characters are those that fall

into ''PDDocEncoding'' - which is basically ISO Latin 1 (aka ISO 8859-1).

Acrobat 9's password scheme is FULLY Unicode compliant and we have tested it

with Unicode values from most/all tables.

If you have a bug number from Adobe on an issue where you were unable to

enter a specific character as part of the password WHEN USING THE ACROBAT 9

PASSWORD SCHEME - please post it.

NOTE: this is not just the use of Acrobat 9, but you have to use the A9

scheme.

Acrobat handles the Unicode canonicalization and normalization just fine, but my point is on the Mac there are characters that cannot be typed into the password edit field. The work-around is to copy and paste in the password (or pass phrase if you prefer) into the password edit field, but the ability to type in some characters is limited.

The fix would be to for Acrobat to wean itself off of the OS based password edit field and replace them with a special use text fields that handle the character masking on input.

Steve