1Crypt::URandom(3)     User Contributed Perl Documentation    Crypt::URandom(3)
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NAME

6       Crypt::URandom - Provide non blocking randomness
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VERSION

9       This document describes Crypt::URandom version 0.39
10

SYNOPSIS

12           use Crypt::URandom();
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14           my $random_string_50_bytes_long = Crypt::URandom::urandom(50);
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16       OR
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18           use Crypt::URandom qw( urandom );
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20           my $random_string_50_bytes_long = urandom(50);
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DESCRIPTION

23       This Module is intended to provide an interface to the strongest
24       available source of non-blocking randomness on the current platform.
25       Platforms currently supported are anything supporting /dev/urandom and
26       versions of Windows greater than or equal to Windows 2000.
27

SUBROUTINES/METHODS

29       "urandom"
30           This function accepts an integer and returns a string of the same
31           size filled with random data.  The first call will initialize the
32           native cryptographic libraries (if necessary) and load all the
33           required Perl libraries.  This call is a buffered read on non Win32
34           platforms.
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36       "urandom_ub"
37           This function accepts an integer and returns a string of the same
38           size filled with random data.  The first call will initialize the
39           native cryptographic libraries (if necessary) and load all the
40           required Perl libraries.  This call is a unbuffered sysread on non
41           Win32 platforms.
42

DIAGNOSTICS

44       "No secure alternative for random number generation for Win32 versions
45       older than W2K"
46           The module cannot run on versions of Windows earlier than Windows
47           2000 as there is no cryptographic functions provided by the
48           operating system.
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50       "Could not import CryptAcquireContext"
51           The module was unable to load the CryptAcquireContextA function
52           from the advapi32 dynamic library.  The advapi32 library cannot
53           probably be loaded.
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55       "CryptAcquireContext failed"
56           The module was unable to call the CryptAcquireContextA function
57           from the advapi32 dynamic library.
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59       "Could not import CryptGenRandom"
60           The module was unable to load the CryptGenRandom function from the
61           advapi32 dynamic library.
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63       "Could not import SystemFunction036"
64           The module was unable to load the SystemFunction036 function from
65           the advapi32 dynamic library.
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67       "The length argument must be supplied and must be an integer"
68           The get method must be called with an integer argument to describe
69           how many random bytes are required.
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71       "CryptGenRandom failed"
72           The Windows 2000 CryptGenRandom method call failed to generate the
73           required amount of randomness
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75       "RtlGenRand failed"
76           The post Windows 2000 RtlGenRand method call failed to generate the
77           required amount of randomness
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79       "Only read n bytes from path"
80           The /dev/urandom device did not return the desired amount of random
81           bytes
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83       "Failed to read from path"
84           The /dev/urandom device returned an error when being read from
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86       "Failed to open path"
87           The /dev/urandom device returned an error when being opened
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CONFIGURATION AND ENVIRONMENT

90       Crypt::URandom requires no configuration files or environment
91       variables.
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DEPENDENCIES

94           If the platform is Win32, the Win32::API module will be required.
95           Otherwise no other modules other than those provided by perl will
96           be required
97

INCOMPATIBILITIES

99       None reported.
100

BUGS AND LIMITATIONS

102       No bugs have been reported.
103
104       Please report any bugs or feature requests to
105       "bug-crypt-urandom@rt.cpan.org", or through the web interface at
106       <http://rt.cpan.org>.
107

AUTHOR

109       David Dick  "<ddick@cpan.org>"
110

ACKNOWLEDGEMENTS

112       The Win32::API code for interacting with Microsoft's CryptoAPI was
113       stolen with extreme gratitude from Crypt::Random::Source::Strong::Win32
114       by Max Kanat-Alexander
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117       Copyright (c) 2023, David Dick "<ddick@cpan.org>". All rights reserved.
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119       This module is free software; you can redistribute it and/or modify it
120       under the same terms as Perl itself.
121

DISCLAIMER OF WARRANTY

123       BECAUSE THIS SOFTWARE IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
124       FOR THE SOFTWARE, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT
125       WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER
126       PARTIES PROVIDE THE SOFTWARE "AS IS" WITHOUT WARRANTY OF ANY KIND,
127       EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
128       WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE
129       ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE SOFTWARE IS WITH
130       YOU. SHOULD THE SOFTWARE PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL
131       NECESSARY SERVICING, REPAIR, OR CORRECTION.
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133       IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
134       WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
135       REDISTRIBUTE THE SOFTWARE AS PERMITTED BY THE ABOVE LICENCE, BE LIABLE
136       TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL, OR
137       CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE
138       SOFTWARE (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING
139       RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A
140       FAILURE OF THE SOFTWARE TO OPERATE WITH ANY OTHER SOFTWARE), EVEN IF
141       SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
142       DAMAGES.
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146perl v5.38.0                      2023-07-20                 Crypt::URandom(3)
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