libressl-RSA_generate_key3
Generate rsa key pair
Usage
Crypto Library (libcrypto, -lcrypto)
#include <openssl/rsa.h>
int
RSA_generate_key_ex(RSA *rsa, int bits, BIGNUM *e, BN_GENCB *cb);
Deprecated:
RSA *
RSA_generate_key(int num, unsigned long e, void (*callback)(int, int, void *), void *cb_arg);
Overview
RSA_generate_key_ex() generates a key pair and stores it in rsa.
The modulus size will be of length 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 cb is not NULL, it will be called as follows using the BN_GENCB_call(3) function:
-
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,
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) for further details.
Return values
RSA_generate_key_ex() returns 1 on success or 0 on error. RSA_generate_key() returns the key on success or NULL on error.
The error codes can be obtained by ERR_get_error(3).