ISO 32000-2:2020 Clause 7: Syntax

7. Syntax

7.3.8.2 Stream extent

Table 5 - Entries common to all stream dictionaries
Key Type Value
F file specification (Optional; PDF 1.2) The file containing the stream data. If this entry is present, the bytes between stream and endstream
shall be ignored. However, the Length entry shouldIssue #10shallIssue #10 still specify the number of those bytes (usually, there are no bytes and Length is 0). The filters that are applied to the file data shall be specified by FFilter and the filter parameters shall be specified by FDecodeParms.

7.4.9 JPXDecode filter

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Data used in PDF image XObjects shall be limited to the JPX baseline set of features, except for
Issue #29

excludingIssue #29 enumerated colour space 19 (CIEJab).
In addition, enumerated colour space 12 (CMYK), which is part of JPX but not JPX baseline, shall be supported in a PDF file. JPX file
structures used in PDF files shall conform to the JPEG 2000 specification.

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7.6.4 Standard security handler

7.6.4.3.3 Algorithm 2.A: Retrieving the file encryption key from an encrypted document in order to decrypt it (revision 6 and later)
  1. Decrypt the 16-byte Perms string using AES-256 in ECB mode with an initialization vector of zero
    Issue #24
    and the file encryption key as the key. ...
7.6.4.4.9 Algorithm 10: Computing the encryption dictionary's Perms (permissions) value (Security handlers of revision 6)
  1. Encrypt the 16-byte block using AES-256 in ECB mode with an initialization vector of zero
    Issue #24
    , using the file encryption key as the key.
    The result (16 bytes) is stored as the Perms string, and checked for validity when the file is opened.
7.6.4.4.12 Algorithm 13: Validating the permissions (Security handlers of revision 6)
  1. Decrypt the 16 byte Perms string using AES-256 in ECB mode with an initialization vector of zero
    Issue #24
    and the file encryption key as the key. ...

7.6.6 Crypt filters

Table 27 - Additional crypt filter dictionary entries for public-key security handlers
Key Type Value
Recipients byteIssue #16 string or array (Required) If the crypt filter is referenced from StmF or StrF in the encryption dictionary, this entry shall be an array of byte strings,
where each byteIssue #16 string shall be a binary-encoded CMS object that shall ...

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If the crypt filter is referenced from a Crypt filter decode parameter dictionary (see "Table 14 - Optional parameters for Crypt filters"),
this entry shall be a byteIssue #16 string that shall be a binary-encoded CMS object that shall ...

7.8.3 Resource dictionaries

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  • For a content stream that is the value of a page's Contents entry (or is an element of an
    array that is the value of that entry)Issue #9
    , the resource dictionary shall
    be designated by the page dictionary's Resources entry or is inherited, as described under 7.7.3.4, "Inheritance of page
    attributes" from some ancestor node of the page object. ...

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Last modified: 16 February 2021