RSAcheckkey(3) OpenSSL RSAcheckkey(3)

NAME
       RSAcheckkey - validate private RSA keys

SYNOPSIS
        #include 

        int RSAcheckkey(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.

RREETTUURRNN VVAALLUUEE
       RSAcheckkey() 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 ERRgeterror(3).

NNOOTTEESS
       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 RSAcheckkey() simply uses the RSA
       structure elements directly, bypassing the RSAMETHOD table altogether
       (and completely violating encapsulation and object-orientation in the
       process).  The best fix will probably be to introduce a "checkkey()"
       handler to the RSAMETHOD function table so that alternative
       implementations can also provide their own verifiers.

SEE ALSO
       rsa(3), ERRgeterror(3)

HISTORY       RSAcheckkey() appeared in OpenSSL 0.9.4.



0.9.7l                            2002-09-25                  RSAcheckkey(3)