static int rsa_alt_check_pair( const void *pub, const void *prv )
{
unsigned char sig[POLARSSL_MPI_MAX_SIZE];
unsigned char hash[32];
size_t sig_len = 0;
int ret;
if( rsa_alt_get_size( prv ) != rsa_get_size( pub ) )
return( POLARSSL_ERR_RSA_KEY_CHECK_FAILED );
memset( hash, 0x2a, sizeof( hash ) );
if( ( ret = rsa_alt_sign_wrap( (void *) prv, POLARSSL_MD_NONE,
hash, sizeof( hash ),
sig, &sig_len, NULL, NULL ) ) != 0 )
{
return( ret );
}
if( rsa_verify_wrap( (void *) pub, POLARSSL_MD_NONE,
hash, sizeof( hash ), sig, sig_len ) != 0 )
{
return( POLARSSL_ERR_RSA_KEY_CHECK_FAILED );
}
return( 0 );
}
/**
Retrieve the maximum possible size of the salt when creating a PKCS#1 PSS signature.
@param padding Type of padding (LTC_PKCS_1_PSS only)
@param hash_idx The index of the desired hash
@param key The RSA key
@return The maximum salt length in bytes or INT_MAX on error.
*/
int rsa_sign_saltlen_get_max_ex(int padding, int hash_idx, rsa_key *key)
{
int ret = INT_MAX;
LTC_ARGCHK(key != NULL);
if ((hash_is_valid(hash_idx) == CRYPT_OK) &&
(padding == LTC_PKCS_1_PSS))
{
ret = rsa_get_size(key);
if (ret < INT_MAX)
{
ret -= (hash_descriptor[hash_idx].hashsize + 2);
} /* if */
} /* if */
return ret;
}
