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I've included my code with comments ... note this is written in Progress (a
4-GL) and it's bit/byte manipulation tools are weak.
- assumg vrc4-orig memory allocation size is 5 bytes (first 5 bytes of
original key)
- assume L_KeyPtr memory allocation size is 10 bytes
- assume Object Number is 20
- assume Generation Number is 0
Anyway ....
/* Take first 5-bytes of original Rc4-Key ... */
DO L_Loop = 1 TO GET-SIZE(vrc4-orig):
PUT-BYTE(L_KeyPtr,L_Loop) = GET-BYTE(vrc4-orig,l_Loop).
END.
/* and then add the object number plus the generation number */
PUT-BYTE( L_KeyPtr, 6) = 0.
PUT-BYTE( L_KeyPtr, 7) = 0.
PUT-BYTE( L_KeyPtr, 8) = ASC(CHR(14)).
PUT-BYTE( L_KeyPtr, 9) = 0.
PUT-BYTE( L_KeyPtr, 10) = 0.
/* Now run the md5 hash against that 10 byte key - orig + obj + gen */
L_Key = EncryptString(L_KeyPtr).
/* Now take the first 10 bytes of the resulting md5 hash as the new key */
SET-SIZE(L_NewKey) = 0.
SET-SIZE(L_NewKey) = 10.
L_Byte = 1.
DO vmd5-loop = 1 TO 20 BY 2:
/* Since Progress returns a -1 when assigning ASC(CHR(0)) we need to
manually assign the null byte */
IF SUBSTR(L_Key,vmd5-loop,2) = "00" THEN
PUT-BYTE(L_NewKey,L_Byte) = 0.
ELSE DO:
FIND FIRST HexArray WHERE HexArray.Hex-Val = SUBSTR(L_Key,vmd5-loop,2).
PUT-BYTE(L_NewKey,L_Byte) = ASC(CHR(HexArray.chr-val)).
END.
L_Byte = L_Byte + 1.
END.
/* Now run ARC4 encryption with the 10 byte key */
L_Encrypted = EnDeCrypt(L_Content, L_NewKey).
TIA,
Gordon
-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] Behalf Of Mark Storer
Sent: Friday, October 17, 2003 3:14 PM
To: '[EMAIL PROTECTED]'
Subject: RE: [PDFdev] Encryption (again)
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_____________________________________________________________
Step 2:
The 5 byte key from algorithm 3.2 has the three byte object number "00 00
14" and gen number "00 00" appended to it. Run this through MD5
Step 3:
Only use the first five bytes of the MD5 hash from step 2.
Can you pst your code? I did, and someone else managed to point out a
rather subtle difference that I had overlooked a couple dozen times.
--Mark Storer
Software Engineer
Cardiff Software
#include <disclaimer>
typdef std::disclaimer<Cardiff> Discard;
> -----Original Message-----
> From: Gordon Campbell [mailto:[EMAIL PROTECTED]
> Sent: Thursday, October 16, 2003 2:56 PM
> To: [EMAIL PROTECTED]
> Subject: RE: [PDFdev] Encryption (again)
>
>
>
> PDFdev is a service provided by PDFzone.com | http://www.pdfzone.com
> _____________________________________________________________
>
> I've done some more checking and if I remove everything from
> my page I don't
> get an error. But as soon as I add "BT ET" into my page I
> get the errors
> described. From this, I'm guessing that I'm probably (must
> be) generating
> the original key incorrectly .... but then, my passwords are working
> correctly. So that just leaves me with the definition of how
> to encrypt
> string data.
>
> Step 1:
> -------
> Obtain Object Number (20) and Generation Number (0)
>
> Step 2:
> -------
> Convert Obj/Gen to "00 00 00 00 14" and extend to original
> n-byte key (I'm
> assuming that this original key is determined in Algorithm
> 3.2 Step 7 -- can
> someone verify this)
>
> Step 3:
> -------
> Run rc4 passing in "BT ET" as the text and the key from Step 2 (above)
>
>
> Does this look correct?
>
> TIA,
> Gordon
>
> -----Original Message-----
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED] Behalf Of Mark Storer
> Sent: Thursday, October 16, 2003 10:29 AM
> To: '[EMAIL PROTECTED]'
> Subject: RE: [PDFdev] Encryption (again)
>
>
>
> PDFdev is a service provided by PDFzone.com | http://www.pdfzone.com
> _____________________________________________________________
>
> The "in document" part of that message leads me to believe that it's a
> structural problem with the document itself rather than
> something wrong with
> the page contents.
>
> When Acrobat runs into a structural problem it often won't
> open the doc (but
> not always). When there's something wrong with the page, the
> document will
> be openend, but the page will be blank. Which are you getting?
>
> If you hold down the 'control' key while clicking the okay
> button on that
> error message, you'll get another, more meaningful error
> message. This
> message is the string associated with the exception that was
> thrown. It may
> or may not be helpful to you.
>
> --Mark Storer
> Software Engineer
> Cardiff Software
> #include <disclaimer>
> typdef std::disclaimer<Cardiff> Discard;
>
>
> > -----Original Message-----
> > From: Gordon Campbell [mailto:[EMAIL PROTECTED]
> > Sent: Thursday, October 16, 2003 7:37 AM
> > To: [EMAIL PROTECTED]
> > Subject: [PDFdev] Encryption (again)
> >
> >
> >
> > PDFdev is a service provided by PDFzone.com | http://www.pdfzone.com
> > _____________________________________________________________
> >
> > Hello,
> >
> > I've gotten to the point in my project where I can verify
> > that I am creating
> > correct User and Master passwords ... and these are accepted
> > by Reader.
> >
> > But, I'm getting the error message 'unrecognized token' plus
> > a bunch of
> > binary data 'in document'.
> >
> > So I'm assuming that I'm not converting my text stream
> > correctly. I'll
> > outline what I'm doing and hopefully someone can point me
> in the right
> > direction.
> >
> > Assume the following:
> > Using Rev 2 of Standard Security Handler (40 Byte encryption)
> > Object ID = 20
> > Generation Number = 0
> > Original Key = 8E 8F 68 E7 C7
> > My 10 digit encryption key would be: 8E 8F 68 E7 C7 00 00 14 00 00
> > My page stream is:
> >
> > "BT" + CHR(13)
> > + "/F1 10 Tf" + CHR(13)
> > + "1 0 0 1 10 742 Tm" + CHR(13)
> > + "10 TL" + CHR(13)
> > + "(Hello World!) Tj" + CHR(13)
> > + "ET" + CHR(13)
> >
> > Questions:
> > - Is my 10 digit key correct?
> > - Should I be encrypted the entire string or each line individually?
> > - Should I be encrypting CHR(13)?
> > - other than Page Streams what other items would I need to
> > encrypt? Assume
> > no images or embedded fonts etc ... a very basic PDF document.
> >
> > If you need more info, please let me know. I'm really
> > pulling my hair out
> > here.
> >
> > Thanks,
> > Gordon
> >
> >
> >
> > To change your subscription:
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> >
>
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>
>
>
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