libressl-RSA_check_key3
Validate private rsa keys
Usage
Crypto Library (libcrypto, -lcrypto)
#include <openssl/rsa.h>
int
RSA_check_key(RSA *rsa);
Overview
This function validates RSA keys. It checks that rsa->p and rsa->q are in fact prime, and that rsa->n satisfies n = p*q.
It also checks that rsa->d and rsa->e satisfy d*e = 1 mod ((p-1)*(q-1)), and that rsa->dmp1, rsa->dmq1, and resa->iqmp are set correctly or are NULL.
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. Therefore, it cannot be used with any arbitrary RSA key object, even if it is otherwise fit for regular RSA operation.
Return values
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).