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1=pod
2
3=head1 NAME
4
4d524e10 5RAND_bytes, RAND_pseudo_bytes - generate random data
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6
7=head1 SYNOPSIS
8
9 #include <openssl/rand.h>
10
11 int RAND_bytes(unsigned char *buf, int num);
12
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13Deprecated:
14
98186eb4 15 #if OPENSSL_API_COMPAT < 0x10100000L
60b52453 16 int RAND_pseudo_bytes(unsigned char *buf, int num);
98186eb4 17 #endif
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18
19=head1 DESCRIPTION
20
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21RAND_bytes() puts B<num> cryptographically strong pseudo-random bytes
22into B<buf>. An error occurs if the PRNG has not been seeded with
23enough randomness to ensure an unpredictable byte sequence.
24
302d38e3 25RAND_pseudo_bytes() has been deprecated. Users should use RAND_bytes() instead.
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26RAND_pseudo_bytes() puts B<num> pseudo-random bytes into B<buf>.
27Pseudo-random byte sequences generated by RAND_pseudo_bytes() will be
28unique if they are of sufficient length, but are not necessarily
29unpredictable. They can be used for non-cryptographic purposes and for
30certain purposes in cryptographic protocols, but usually not for key
31generation etc.
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33The contents of B<buf> is mixed into the entropy pool before retrieving
34the new pseudo-random bytes unless disabled at compile time (see FAQ).
35
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36=head1 RETURN VALUES
37
38RAND_bytes() returns 1 on success, 0 otherwise. The error code can be
9b86974e 39obtained by L<ERR_get_error(3)>. RAND_pseudo_bytes() returns 1 if the
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40bytes generated are cryptographically strong, 0 otherwise. Both
41functions return -1 if they are not supported by the current RAND
42method.
43
44=head1 SEE ALSO
45
b97fdb57 46L<RAND_bytes(3)>, L<ERR_get_error(3)>,
9b86974e 47L<RAND_add(3)>
60b52453 48
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49=head1 COPYRIGHT
50
51Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.
52
53Licensed under the OpenSSL license (the "License"). You may not use
54this file except in compliance with the License. You can obtain a copy
55in the file LICENSE in the source distribution or at
56L<https://www.openssl.org/source/license.html>.
57
58=cut