RSA_generate_key(3)         OpenSSL         RSA_generate_key(3)





NAME
       RSA_generate_key - generate RSA key pair

SYNOPSIS
        #include <openssl/rsa.h>

        RSA *RSA_generate_key(int num, unsigned long e,
           void (*callback)(int,int,void *), void *cb_arg);

DESCRIPTION
       RSA_generate_key() generates a key pair and returns it
       in a newly allocated RSA structure. The pseudo-random
       number generator must be seeded prior to calling
       RSA_generate_key().

       The modulus size will be num bits, and the public expo-
       nent will be e. Key sizes with num < 1024 should be con-
       sidered insecure.  The exponent is an odd number, typi-
       cally 3, 17 or 65537.

       A callback function may be used to provide feedback
       about the progress of the key generation. If callback is
       not NULL, it will be called as follows:

       o   While a random prime number is generated, it is
           called as described in BN_generate_prime(3).

       o   When the n-th randomly generated prime is rejected
           as not suitable for the key, callback(2, n, cb_arg)
           is called.

       o   When a random p has been found with p-1 relatively
           prime to e, it is called as callback(3, 0, cb_arg).

       The process is then repeated for prime q with call-
       back(3, 1, cb_arg).

RETURN VALUE
       If key generation fails, RSA_generate_key() returns
       NULL; the error codes can be obtained by
       ERR_get_error(3).

BUGS
       callback(2, x, cb_arg) is used with two different mean-
       ings.

       RSA_generate_key() goes into an infinite loop for ille-
       gal input values.

SEE ALSO
       ERR_get_error(3), rand(3), rsa(3), RSA_free(3)

HISTORY
       The cb_arg argument was added in SSLeay 0.9.0.



0.9.7c                     2002-09-25       RSA_generate_key(3)
