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Diffstat (limited to 'manual/qpdf-manual.xml')
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diff --git a/manual/qpdf-manual.xml b/manual/qpdf-manual.xml index 8d68db9d..2cb6be5d 100644 --- a/manual/qpdf-manual.xml +++ b/manual/qpdf-manual.xml @@ -1851,6 +1851,31 @@ outfile.pdf</option> preserved as clear-text if it is that way in the original file. </para> </sect1> + <sect1 id="ref.random-numbers"> + <title>Random Number Generation</title> + <para> + QPDF generates random numbers to support generation of encrypted + data. Versions prior to 5.0.1 used <function>random</function> or + <function>rand</function> from <filename>stdlib</filename> to + generate random numbers. Version 5.0.1, if available, used + operating system-provided secure random number generation instead, + enabling use of <filename>stdlib</filename> random number + generation only if enabled by a compile-time option. Starting in + version 5.1.0, use of insecure random numbers was disabled unless + enabled at compile time. Starting in version 5.1.0, it is also + possible for you to disable use of OS-provided secure random + numbers. This is especially useful on Windows if you want to + avoid a dependency on Microsoft's cryptography API. In this case, + you must provide your own random data provider. Regardless of how + you compile qpdf, starting in version 5.1.0, it is possible for + you to provide your own random data provider at runtime. This + would enable you to use some software-based secure pseudorandom + number generator and to avoid use of whatever the operating system + provides. For details on how to do this, please refer to the + top-level README file in the source distribution and to comments + in <filename>QUtil.hh</filename>. + </para> + </sect1> <sect1 id="ref.adding-and-remove-pages"> <title>Adding and Removing Pages</title> <para> |