RSA_check_key(3)

NAME
RSA_check_key - validate private RSA keys

SYNOPSIS
 #include <openssl/rsa.h>

 int RSA_check_key(RSA *rsa);

DESCRIPTION
This function validates RSA keys. It checks that p and q are in fact prime, and that n = p*q.

It also checks that d*e = 1 mod (p-1*q-1), and that dmp1, dmq1 and iqmp are set correctly or are NULL.

As such, this function can not be used with any arbitrary RSA key object, even if it is otherwise fit for regular RSA operation. See NOTES for more information.

RETURN VALUE
RSA_check_key() returns 1 if rsa is a valid RSA key, and 0 otherwise. -1 is returned if an error occurs while checking the key.

If the key is invalid or an error occurred, the reason code can be obtained using ERR_get_error(3).

NOTES
This function does not work on RSA public keys that have only the modulus and public exponent elements populated. It performs integrity checks on all the RSA key material, so the RSA key structure must contain all the private key data too.

SEE ALSO
rsa(3), err(3)

HISTORY
RSA_check() appeared in OpenSSL 0.9.4.