+int BN_X931_generate_Xpq(BIGNUM *Xp, BIGNUM *Xq, int nbits, BN_CTX *ctx);
+
+int BN_X931_derive_prime_ex(BIGNUM *p, BIGNUM *p1, BIGNUM *p2,
+ const BIGNUM *Xp, const BIGNUM *Xp1, const BIGNUM *Xp2,
+ const BIGNUM *e, BN_CTX *ctx, BN_GENCB *cb);
+int BN_X931_generate_prime_ex(BIGNUM *p, BIGNUM *p1, BIGNUM *p2,
+ BIGNUM *Xp1, BIGNUM *Xp2,
+ const BIGNUM *Xp,
+ const BIGNUM *e, BN_CTX *ctx,
+ BN_GENCB *cb);
+