mirror of
https://github.com/openssl/openssl.git
synced 2024-12-27 06:21:43 +08:00
1d5099dec6
Documentation fix ups as a result of feedback received. Reviewed-by: Tim Hudson <tjh@openssl.org> Reviewed-by: Richard Levitte <levitte@openssl.org>
78 lines
2.3 KiB
Plaintext
78 lines
2.3 KiB
Plaintext
=pod
|
|
|
|
=head1 NAME
|
|
|
|
rand - pseudo-random number generator
|
|
|
|
=head1 SYNOPSIS
|
|
|
|
#include <openssl/rand.h>
|
|
|
|
int RAND_set_rand_engine(ENGINE *engine);
|
|
|
|
int RAND_bytes(unsigned char *buf, int num);
|
|
int RAND_pseudo_bytes(unsigned char *buf, int num);
|
|
|
|
void RAND_seed(const void *buf, int num);
|
|
void RAND_add(const void *buf, int num, int entropy);
|
|
int RAND_status(void);
|
|
|
|
int RAND_load_file(const char *file, long max_bytes);
|
|
int RAND_write_file(const char *file);
|
|
const char *RAND_file_name(char *file, size_t num);
|
|
|
|
int RAND_egd(const char *path);
|
|
|
|
void RAND_set_rand_method(const RAND_METHOD *meth);
|
|
const RAND_METHOD *RAND_get_rand_method(void);
|
|
RAND_METHOD *RAND_OpenSSL(void);
|
|
|
|
/* For Win32 only */
|
|
void RAND_screen(void);
|
|
int RAND_event(UINT, WPARAM, LPARAM);
|
|
|
|
Deprecated:
|
|
|
|
#if OPENSSL_API_COMPAT < 0x10100000L
|
|
void RAND_cleanup(void)
|
|
#endif
|
|
|
|
=head1 DESCRIPTION
|
|
|
|
Since the introduction of the ENGINE API, the recommended way of controlling
|
|
default implementations is by using the ENGINE API functions. The default
|
|
B<RAND_METHOD>, as set by RAND_set_rand_method() and returned by
|
|
RAND_get_rand_method(), is only used if no ENGINE has been set as the default
|
|
"rand" implementation. Hence, these two functions are no longer the recommended
|
|
way to control defaults.
|
|
|
|
If an alternative B<RAND_METHOD> implementation is being used (either set
|
|
directly or as provided by an ENGINE module), then it is entirely responsible
|
|
for the generation and management of a cryptographically secure PRNG stream. The
|
|
mechanisms described below relate solely to the software PRNG implementation
|
|
built in to OpenSSL and used by default.
|
|
|
|
These functions implement a cryptographically secure pseudo-random
|
|
number generator (PRNG). It is used by other library functions for
|
|
example to generate random keys, and applications can use it when they
|
|
need randomness.
|
|
|
|
A cryptographic PRNG must be seeded with unpredictable data such as
|
|
mouse movements or keys pressed at random by the user. This is
|
|
described in L<RAND_add(3)>. Its state can be saved in a seed file
|
|
(see L<RAND_load_file(3)>) to avoid having to go through the
|
|
seeding process whenever the application is started.
|
|
|
|
L<RAND_bytes(3)> describes how to obtain random data from the
|
|
PRNG.
|
|
|
|
=head1 SEE ALSO
|
|
|
|
L<BN_rand(3)>, L<RAND_add(3)>,
|
|
L<RAND_load_file(3)>, L<RAND_egd(3)>,
|
|
L<RAND_bytes(3)>,
|
|
L<RAND_set_rand_method(3)>,
|
|
L<RAND_cleanup(3)>
|
|
|
|
=cut
|