NAME    [Toc]    [Back]

       RAND_set_rand_method, RAND_get_rand_method, RAND_SSLeay -
       select RAND method

LIBRARY    [Toc]    [Back]

       libcrypto, -lcrypto

SYNOPSIS    [Toc]    [Back]

        #include <openssl/rand.h>

        void RAND_set_rand_method(RAND_METHOD *meth);

        RAND_METHOD *RAND_get_rand_method(void);

        RAND_METHOD *RAND_SSLeay(void);

DESCRIPTION    [Toc]    [Back]

       A RAND_METHOD specifies the functions that OpenSSL uses
       for random number generation. By modifying the method,
       alternative implementations such as hardware RNGs may be
       used.  Initially, the default is to use the OpenSSL internal
 implementation. RAND_SSLeay() returns a pointer to
       that method.

       RAND_set_rand_method() sets the RAND method to meth.
       RAND_get_rand_method() returns a pointer to the current
       method.

THE RAND_METHOD STRUCTURE    [Toc]    [Back]

        typedef struct rand_meth_st
        {
               void (*seed)(const void *buf, int num);
               int (*bytes)(unsigned char *buf, int num);
               void (*cleanup)(void);
               void (*add)(const void *buf, int num, int entropy);
               int (*pseudorand)(unsigned char *buf, int num);
               int (*status)(void);
        } RAND_METHOD;

       The components point to the implementation of RAND_seed(),
       RAND_bytes(), RAND_cleanup(), RAND_add(),
       RAND_pseudo_rand() and RAND_status().  Each component may
       be NULL if the function is not implemented.

RETURN VALUES    [Toc]    [Back]

       RAND_set_rand_method() returns no value.
       RAND_get_rand_method() and RAND_SSLeay() return pointers
       to the respective methods.

SEE ALSO    [Toc]    [Back]

       openssl_rand(3)

HISTORY    [Toc]    [Back]

       RAND_set_rand_method(), RAND_get_rand_method() and
       RAND_SSLeay() are available in all versions of OpenSSL.



2000-07-22                    0.9.6g      RAND_set_rand_method(3)