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 exponent will be e. Key sizes with num < 1024
should be considered insecure. The exponent is an odd number, typically
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:
While a random prime number is generated,
it is called as described in BN_generate_prime(3).
When the n-th randomly generated prime is rejected
as not suitable for the key, callback(2, n, cb_arg) is called.
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 callback(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).
Restrictions
callback(2, x, cb_arg) is used with two
different meanings.
RSA_generate_key() goes into an infinite loop for illegal
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.
