UM *x, const BIGNUM *a, const BIGNUM *u,
                            OSSL_LIB_CTX *libctx, const char *propq);
BIGNUM *SRP_Calc_client_key(const BIGNUM *N, const BIGNUM *B, const BIGNUM *g,
                            const BIGNUM *x, const BIGNUM *a, const BIGNUM *u);
BIGNUM *SRP_Calc_x_ex(const BIGNUM *s, const char *user, const char *pass,
                      OSSL_LIB_CTX *libctx, const char *propq);
BIGNUM *SRP_Calc_x(const BIGNUM *s, const char *user, const char *pass);
BIGNUM *SRP_Calc_A(const BIGNU