Adobe 12020596 User Guide - Page 17

The value of, is 4 or less, The value for, TABLE 3.19 Additional encryption dictionary entries

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Adobe Acrobat SDK Adobe® Supplement to the ISO 32000 Syntax (Chapter 3 in PDF Reference) 3.5.2 Standard Security Handler 17 TABLE 3.19 Additional encryption dictionary entries for the standard security handler KEY TYPE VALUE O string (Required) A string used in computing the encryption key. The value of the string depends on the value of the revision number, the R entry described above. The value of R is 4 or less: A 32-byte string, based on both the owner and user passwords, that is used in computing the encryption key and in determining whether a valid owner password was entered. The value for R is 5: (ExtensionLevel 3) A 48-byte string, based on the owner and user passwords, that is used in computing the encryption key and in determining whether a valid owner password was entered. For more information, see "Encryption Key Algorithm" on page 124 and "Password Algorithms" on page 126. U string (Required) A string based on the user password. The value of the string depends on the value of the revision number, the R entry described above. The value of R is 4 or less: A 32-byte string, based on the user password, that is used in determining whether to prompt the user for a password and, if so, whether a valid user or owner password was entered. The value for R is 5: (ExtensionLevel 3) A 48-byte string, based on the user password, that is used in determining whether to prompt the user for a password and, if so, whether a valid user password was entered. For more information, see "Password Algorithms" on page 126. OE string (ExtensionLevel 3; required if R is 5) A 32-byte string, based on the owner and user passwords, that is used in computing the encryption key. For more information, see "Password Algorithms" on page 126. UE string (ExtensionLevel 3; required if R is 5) A 32-byte string, based on the user password, that is used in computing the encryption key. For more information, see "Password Algorithms" on page 126. P integer (Required) A set of flags specifying which operations are permitted when the document is opened with user access (see Table 3.20).

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Adobe Acrobat SDK
Syntax (Chapter 3 in PDF Reference)
Adobe® Supplement to the ISO 32000
3.5.2 Standard Security Handler
17
O
string
(
Required
) A string used in computing the encryption key.
The value of the string depends on the value of the
revision number, the
R
entry described above.
The value of
R
is 4 or less:
A 32-byte string, based on
both the owner and user passwords, that is used in
computing the encryption key and in determining
whether a valid owner password was entered.
The value for
R
is 5:
(
ExtensionLevel 3
) A 48-byte string,
based on the owner and user passwords, that is used in
computing the encryption key and in determining
whether a valid owner password was entered.
For more information, see “Encryption Key Algorithm” on
page 124 and “Password Algorithms” on page 126.
U
string
(
Required
) A string based on the user password. The value
of the string depends on the value of the revision number,
the
R
entry described above.
The value of
R
is 4 or less:
A 32-byte string, based on
the user password, that is used in determining
whether to prompt the user for a password and, if so,
whether a valid user or owner password was entered.
The value for
R
is 5:
(
ExtensionLevel 3
) A 48-byte string,
based on the user password, that is used in
determining whether to prompt the user for a
password and, if so, whether a valid user password was
entered.
For more information, see “Password Algorithms” on page
126.
OE
string
(
ExtensionLevel 3; required if
R
is
5
) A 32-byte string, based
on the owner and user passwords, that is used in
computing the encryption key.
For more information, see “Password Algorithms” on page
126.
UE
string
(
ExtensionLevel 3; required if
R
is
5
) A 32-byte string, based
on the
user password, that is used in computing the
encryption key.
For more information, see “Password Algorithms” on page
126.
P
integer
(
Required
) A set of flags specifying which operations are
permitted when the document is opened with user access
(see Table 3.20).
TABLE 3.19 Additional encryption dictionary entries for the standard security handler
KEY
TYPE
VALUE