RSA_check_key 3 2003-07-24 0.9.9-dev OpenSSL
NAME
RSA_check_key - validate private RSA keys
LIBRARY
libcrypto, -lcrypto
SYNOPSIS
#include
int RSA_check_key(RSA *rsa);
DESCRIPTION
This function validates RSA keys. It checks that pp and qq are
in fact prime, and that nn == pp**qq.
It also checks that dd**ee == 11 mmoodd ((pp--11**qq--11)),
and that ddmmpp11, ddmmqq11 and iiqqmmpp are set correctly or are NNUULLLL.
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 NNOOTTEESS for more
information.
RETURN VALUE
_R_S_A___c_h_e_c_k___k_e_y_(_) returns 1 if rrssaa 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 _E_R_R___g_e_t___e_r_r_o_r(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.
Unlike most other RSA functions, this function does nnoott work
transparently with any underlying ENGINE implementation because it uses the
key data in the RSA structure directly. An ENGINE implementation can
override the way key data is stored and handled, and can even provide
support for HSM keys - in which case the RSA structure may contain nnoo
key data at all! If the ENGINE in question is only being used for
acceleration or analysis purposes, then in all likelihood the RSA key data
is complete and untouched, but this can't be assumed in the general case.
BUGS
A method of verifying the RSA key using opaque RSA API functions might need
to be considered. Right now _R_S_A___c_h_e_c_k___k_e_y_(_) simply uses the RSA structure
elements directly, bypassing the RSA_METHOD table altogether (and
completely violating encapsulation and object-orientation in the process).
The best fix will probably be to introduce a "_c_h_e_c_k___k_e_y_(_)" handler to the
RSA_METHOD function table so that alternative implementations can also
provide their own verifiers.
SEE ALSO
_o_p_e_n_s_s_l___r_s_a(3), _E_R_R___g_e_t___e_r_r_o_r(3)
HISTORY
_R_S_A___c_h_e_c_k___k_e_y_(_) appeared in OpenSSL 0.9.4.