+#include <openssl/bn.h>
+#include <openssl/crypto.h>
+
+#define DH_FLAG_CACHE_MONT_P 0x01
+
+typedef struct dh_st DH;
+
+typedef struct dh_method {
+ const char *name;
+ /* Methods here */
+ int (*generate_key)(DH *dh);
+ int (*compute_key)(unsigned char *key,BIGNUM *pub_key,DH *dh);
+ int (*bn_mod_exp)(DH *dh, BIGNUM *r, BIGNUM *a, const BIGNUM *p,
+ const BIGNUM *m, BN_CTX *ctx,
+ BN_MONT_CTX *m_ctx); /* Can be null */
+
+ int (*init)(DH *dh);
+ int (*finish)(DH *dh);
+ int flags;
+ char *app_data;
+} DH_METHOD;
+
+struct dh_st