RSA_generate_key_ex, RSA_generate_key - generate RSA key pair
int RSA_generate_key_ex(RSA *rsa, int bits, BIGNUM *e, BN_GENCB *cb);
RSA *RSA_generate_key(int num, unsigned long e,
void (*callback)(int,int,void *), void *cb_arg);
generates a key pair and stores it in the
structure provided in rsa
. The pseudo-random number
generator must be seeded prior to calling RSA_generate_key_ex()
The modulus size will be of length bits
, and the public exponent will be
. 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 cb
is not NULL
, it will be called as follows
using the BN_GENCB_call()
function described on the
- While a random prime number is generated, it is called as described in
- When the n-th randomly generated prime is rejected as not suitable for the
key, BN_GENCB_call(cb, 2, n) is called.
- When a random p has been found with p-1 relatively prime to e, it
is called as BN_GENCB_call(cb, 3, 0).
The process is then repeated for prime q with BN_GENCB_call(cb, 3, 1)
RSA_generate_key is deprecated (new applications should use RSA_generate_key_ex
instead). RSA_generate_key works in the same way as RSA_generate_key_ex except
it uses "old style" call backs. See BN_generate_prime(3)
If key generation fails, RSA_generate_key()
The error codes can be obtained by ERR_get_error(3)
BN_GENCB_call(cb, 2, x)
is used with two different meanings.
goes into an infinite loop for illegal input values.
argument was added in SSLeay 0.9.0.