mirror of https://github.com/openssl/openssl.git
79 lines
2.0 KiB
Plaintext
79 lines
2.0 KiB
Plaintext
=pod
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=head1 NAME
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RAND_bytes, RAND_priv_bytes, RAND_pseudo_bytes - generate random data
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=head1 SYNOPSIS
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#include <openssl/rand.h>
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int RAND_bytes(unsigned char *buf, int num);
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int RAND_priv_bytes(unsigned char *buf, int num);
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Deprecated since OpenSSL 1.1.0, can be hidden entirely by defining
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B<OPENSSL_API_COMPAT> with a suitable version value, see
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L<openssl_user_macros(7)>:
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int RAND_pseudo_bytes(unsigned char *buf, int num);
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=head1 DESCRIPTION
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RAND_bytes() puts B<num> cryptographically strong pseudo-random bytes
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into B<buf>.
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RAND_priv_bytes() has the same semantics as RAND_bytes(). It is intended to
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be used for generating values that should remain private. If using the
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default RAND_METHOD, this function uses a separate "private" PRNG
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instance so that a compromise of the "public" PRNG instance will not
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affect the secrecy of these private values, as described in L<RAND(7)>
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and L<RAND_DRBG(7)>.
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=head1 NOTES
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Always check the error return value of RAND_bytes() and
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RAND_priv_bytes() and do not take randomness for granted: an error occurs
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if the CSPRNG has not been seeded with enough randomness to ensure an
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unpredictable byte sequence.
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=head1 RETURN VALUES
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RAND_bytes() and RAND_priv_bytes()
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return 1 on success, -1 if not supported by the current
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RAND method, or 0 on other failure. The error code can be
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obtained by L<ERR_get_error(3)>.
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=head1 SEE ALSO
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L<RAND_add(3)>,
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L<RAND_bytes(3)>,
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L<RAND_priv_bytes(3)>,
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L<ERR_get_error(3)>,
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L<RAND(7)>,
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L<RAND_DRBG(7)>
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=head1 HISTORY
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=over 2
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=item *
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RAND_pseudo_bytes() was deprecated in OpenSSL 1.1.0; use RAND_bytes() instead.
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=item *
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The RAND_priv_bytes() function was added in OpenSSL 1.1.1.
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=back
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=head1 COPYRIGHT
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Copyright 2000-2019 The OpenSSL Project Authors. All Rights Reserved.
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Licensed under the Apache License 2.0 (the "License"). You may not use
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this file except in compliance with the License. You can obtain a copy
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in the file LICENSE in the source distribution or at
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L<https://www.openssl.org/source/license.html>.
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=cut
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