1RAND_BYTES(3)                       OpenSSL                      RAND_BYTES(3)
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NAME

6       RAND_bytes, RAND_priv_bytes, RAND_pseudo_bytes - generate random data
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SYNOPSIS

9        #include <openssl/rand.h>
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11        int RAND_bytes(unsigned char *buf, int num);
12        int RAND_priv_bytes(unsigned char *buf, int num);
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14       Deprecated:
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16        #if OPENSSL_API_COMPAT < 0x10100000L
17        int RAND_pseudo_bytes(unsigned char *buf, int num);
18        #endif
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DESCRIPTION

21       RAND_bytes() puts num cryptographically strong pseudo-random bytes into
22       buf.
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24       RAND_priv_bytes() has the same semantics as RAND_bytes().  It is
25       intended to be used for generating values that should remain private.
26       If using the default RAND_METHOD, this function uses a separate
27       "private" PRNG instance so that a compromise of the "public" PRNG
28       instance will not affect the secrecy of these private values, as
29       described in RAND(7) and RAND_DRBG(7).
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NOTES

32       Always check the error return value of RAND_bytes() and
33       RAND_priv_bytes() and do not take randomness for granted: an error
34       occurs if the CSPRNG has not been seeded with enough randomness to
35       ensure an unpredictable byte sequence.
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RETURN VALUES

38       RAND_bytes() and RAND_priv_bytes() return 1 on success, -1 if not
39       supported by the current RAND method, or 0 on other failure. The error
40       code can be obtained by ERR_get_error(3).
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HISTORY

43       · RAND_pseudo_bytes() was deprecated in OpenSSL 1.1.0; use RAND_bytes()
44         instead.
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46       · RAND_priv_bytes() was added in OpenSSL 1.1.1.
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SEE ALSO

49       RAND_add(3), RAND_bytes(3), RAND_priv_bytes(3), ERR_get_error(3),
50       RAND(7), RAND_DRBG(7)
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53       Copyright 2000-2018 The OpenSSL Project Authors. All Rights Reserved.
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55       Licensed under the OpenSSL license (the "License").  You may not use
56       this file except in compliance with the License.  You can obtain a copy
57       in the file LICENSE in the source distribution or at
58       <https://www.openssl.org/source/license.html>.
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621.1.1                             2018-09-11                     RAND_BYTES(3)
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