From 6a64e150fd677162dcd62249b8e93242801d5232 Mon Sep 17 00:00:00 2001 From: Jay Berkenbilt Date: Sun, 14 Jan 2018 14:07:56 -0500 Subject: Update manual for 7.1.0 --- manual/qpdf-manual.xml | 91 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 91 insertions(+) (limited to 'manual') diff --git a/manual/qpdf-manual.xml b/manual/qpdf-manual.xml index b006a4ef..8c8f4d5b 100644 --- a/manual/qpdf-manual.xml +++ b/manual/qpdf-manual.xml @@ -378,6 +378,35 @@ make + + + + + Overrides the usual computation/retrieval of the PDF file's + encryption key from user/owner password with an explicit + specification of the encryption key. When this option is + specified, the argument to the + option is interpreted as a hexadecimal-encoded key value. This + only applies to the password used to open the main input file. + It does not apply to other files opened by + or other options or to files being + written. + + + Most users will never have a need for this option, and no + standard viewers support this mode of operation, but it can be + useful for forensic or investigatory purposes. For example, if + a PDF file is encrypted with an unknown password, a + brute-force attack using the key directly is sometimes more + efficient than one using the password. Also, if a file is + heavily damaged, it may be possible to derive the encryption + key and recover parts of the file using it directly. To expose + the encryption key used by an encrypted file that you can open + normally, use the + option. + + + @@ -1284,6 +1313,24 @@ outfile.pdf + + + + + When encryption information is being displayed, as when + or + is given, display the computed or retrieved encryption key as + a hexadecimal string. This value is not ordinarily useful to + users, but it can be used as the argument to + if the + is specified. Note + that, when PDF files are encrypted, passwords and other + metadata are used only to compute an encryption key, and the + encryption key is what is actually used for encryption. This + enables retrieval of that key. + + + @@ -2935,6 +2982,50 @@ print "\n"; ChangeLog in the source distribution. + + 7.1.0: January 14, 2018 + + + + + PDF files contain streams that may be compressed with various + compression algorithms which, in some cases, may be enhanced + by various predictor functions. Previously only the PNG up + predictor was supported. In this version, all the PNG + predictors as well as the TIFF predictor are supported. This + increases the range of files that qpdf is able to handle. + + + + + QPDF now allows a raw encryption key to be specified in place + of a password when opening encrypted files, and will + optionally display the encryption key used by a file. This is + a non-standard operation, but it can be useful in certain + situations. Please see the discussion of + in or the comments around + QPDF::setPasswordIsHexKey in + QPDF.hh for additional details. + + + + + Bug fix: numbers ending with a trailing decimal point are now + properly recognized as numbers. + + + + + Bug fix: when building qpdf from source on some platforms + (especially MacOS), the build could get confused by older + versions of qpdf installed on the system. This has been + corrected. + + + + + 7.0.0: September 15, 2017 -- cgit v1.2.3-54-g00ecf