1RAND_SET_RAND_METHOD(3ossl)         OpenSSL        RAND_SET_RAND_METHOD(3ossl)
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NAME

6       RAND_set_rand_method, RAND_get_rand_method, RAND_OpenSSL - select RAND
7       method
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SYNOPSIS

10        #include <openssl/rand.h>
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12       The following functions have been deprecated since OpenSSL 3.0, and can
13       be hidden entirely by defining OPENSSL_API_COMPAT with a suitable
14       version value, see openssl_user_macros(7):
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16        RAND_METHOD *RAND_OpenSSL(void);
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18        int RAND_set_rand_method(const RAND_METHOD *meth);
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20        const RAND_METHOD *RAND_get_rand_method(void);
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DESCRIPTION

23       All of the functions described on this page are deprecated.
24       Applications should instead use RAND_set_DRBG_type(3), EVP_RAND(3) and
25       EVP_RAND(7).
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27       A RAND_METHOD specifies the functions that OpenSSL uses for random
28       number generation.
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30       RAND_OpenSSL() returns the default RAND_METHOD implementation by
31       OpenSSL.  This implementation ensures that the PRNG state is unique for
32       each thread.
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34       If an ENGINE is loaded that provides the RAND API, however, it will be
35       used instead of the method returned by RAND_OpenSSL().  This is
36       deprecated in OpenSSL 3.0.
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38       RAND_set_rand_method() makes meth the method for PRNG use.  If an
39       ENGINE was providing the method, it will be released first.
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41       RAND_get_rand_method() returns a pointer to the current RAND_METHOD.
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THE RAND_METHOD STRUCTURE

44        typedef struct rand_meth_st {
45            int (*seed)(const void *buf, int num);
46            int (*bytes)(unsigned char *buf, int num);
47            void (*cleanup)(void);
48            int (*add)(const void *buf, int num, double entropy);
49            int (*pseudorand)(unsigned char *buf, int num);
50            int (*status)(void);
51        } RAND_METHOD;
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53       The fields point to functions that are used by, in order, RAND_seed(),
54       RAND_bytes(), internal RAND cleanup, RAND_add(), RAND_pseudo_rand() and
55       RAND_status().  Each pointer may be NULL if the function is not
56       implemented.
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RETURN VALUES

59       RAND_set_rand_method() returns 1 on success and 0 on failure.
60       RAND_get_rand_method() and RAND_OpenSSL() return pointers to the
61       respective methods.
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SEE ALSO

64       EVP_RAND(3), RAND_set_DRBG_type(3), RAND_bytes(3), ENGINE_by_id(3),
65       EVP_RAND(7), RAND(7)
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HISTORY

68       All of these functions were deprecated in OpenSSL 3.0.
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71       Copyright 2000-2021 The OpenSSL Project Authors. All Rights Reserved.
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73       Licensed under the Apache License 2.0 (the "License").  You may not use
74       this file except in compliance with the License.  You can obtain a copy
75       in the file LICENSE in the source distribution or at
76       <https://www.openssl.org/source/license.html>.
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803.0.9                             2023-07-27       RAND_SET_RAND_METHOD(3ossl)
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