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 0.36
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
34

DIAGNOSTICS

36       "No secure alternative for random number generation for Win32 versions
37       older than W2K"
38           The module cannot run on versions of Windows earlier than Windows
39           2000 as there is no cryptographic functions provided by the
40           operating system.
41
42       "Could not import CryptAcquireContext"
43           The module was unable to load the CryptAcquireContextA function
44           from the advapi32 dynamic library.  The advapi32 library cannot
45           probably be loaded.
46
47       "CryptAcquireContext failed"
48           The module was unable to call the CryptAcquireContextA function
49           from the advapi32 dynamic library.
50
51       "Could not import CryptGenRandom"
52           The module was unable to load the CryptGenRandom function from the
53           advapi32 dynamic library.
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55       "Could not import SystemFunction036"
56           The module was unable to load the SystemFunction036 function from
57           the advapi32 dynamic library.
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59       "The length argument must be supplied and must be an integer"
60           The get method must be called with an integer argument to describe
61           how many random bytes are required.
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63       "CryptGenRandom failed"
64           The Windows 2000 CryptGenRandom method call failed to generate the
65           required amount of randomness
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67       "RtlGenRand failed"
68           The post Windows 2000 RtlGenRand method call failed to generate the
69           required amount of randomness
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71       "Only read n bytes from path"
72           The /dev/urandom device did not return the desired amount of random
73           bytes
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75       "Failed to read from path"
76           The /dev/urandom device returned an error when being read from
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78       "Failed to open path"
79           The /dev/urandom device returned an error when being opened
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CONFIGURATION AND ENVIRONMENT

82       Crypt::URandom requires no configuration files or environment
83       variables.
84

DEPENDENCIES

86           If the platform is Win32, the Win32::API module will be required.
87           Otherwise no other modules other than those provided by perl will
88           be required
89

INCOMPATIBILITIES

91       None reported.
92

BUGS AND LIMITATIONS

94       No bugs have been reported.
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96       Please report any bugs or feature requests to
97       "bug-crypt-urandom@rt.cpan.org", or through the web interface at
98       <http://rt.cpan.org>.
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AUTHOR

101       David Dick  "<ddick@cpan.org>"
102

ACKNOWLEDGEMENTS

104       The Win32::API code for interacting with Microsoft's CryptoAPI was
105       stolen with extreme gratitude from Crypt::Random::Source::Strong::Win32
106       by Max Kanat-Alexander
107

109       Copyright (c) 2011, David Dick "<ddick@cpan.org>". All rights reserved.
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111       This module is free software; you can redistribute it and/or modify it
112       under the same terms as Perl itself.
113

DISCLAIMER OF WARRANTY

115       BECAUSE THIS SOFTWARE IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
116       FOR THE SOFTWARE, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT
117       WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER
118       PARTIES PROVIDE THE SOFTWARE "AS IS" WITHOUT WARRANTY OF ANY KIND,
119       EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
120       WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE
121       ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE SOFTWARE IS WITH
122       YOU. SHOULD THE SOFTWARE PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL
123       NECESSARY SERVICING, REPAIR, OR CORRECTION.
124
125       IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
126       WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
127       REDISTRIBUTE THE SOFTWARE AS PERMITTED BY THE ABOVE LICENCE, BE LIABLE
128       TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL, OR
129       CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE
130       SOFTWARE (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING
131       RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A
132       FAILURE OF THE SOFTWARE TO OPERATE WITH ANY OTHER SOFTWARE), EVEN IF
133       SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
134       DAMAGES.
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138perl v5.34.0                      2021-07-22                 Crypt::URandom(3)
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