--- /dev/null
+/*
+
+ silcdh.h
+
+ Author: Pekka Riikonen <priikone@poseidon.pspt.fi>
+
+ Copyright (C) 2001 Pekka Riikonen
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+*/
+/* PKCS #3 compliant Diffie Hellman key agreement protocol implementation.
+ This is used as part of SKE (SILC Key Exchange) protocol. */
+
+#ifndef SILCDH_H
+#define SILCDH_H
+
+#include "silcmp.h"
+#include "silcrng.h"
+
+/* Forward declaration of Diffie Hellman context */
+typedef struct SilcDHStruct *SilcDH;
+
+/* XXX Move to source file */
+/* Diffie Hellman context. This includes the DH parameters including the
+ negotiated key material. */
+struct SilcDHStruct {
+ SilcInt *g; /* Global base (generator) */
+ SilcInt *p; /* Global prime (modulus) */
+ SilcInt *my_x; /* x, My private value (random) */
+ SilcInt *my_y; /* y, My public value (y = g ^ x mod p) */
+ SilcInt *your_y; /* y', Your public value (y' = g ^ x' mod p) */
+ SilcInt *z; /* The computed secret key (z = y' ^ x mod p) */
+
+ SilcRng rng; /* RNG */
+};
+
+/* Allocate DH context. The `rng' must be initialized random number generator
+ context, the `g' is the public base generator used in the negotiation and
+ the `p' is the public prime used in the negotiation. Returns NULL on error
+ or allocated DH context on success. */
+SilcDH silc_dh_alloc(SilcRng rng, SilcInt *g, SilcInt *p);
+
+/* Frees the DH context. Does not free the RNG context given in the
+ allocation. Frees all the allocated data inside the DH context. */
+void silc_dh_free(SilcDH dh);
+
+/* Generates random private value `x' such that 1 < x < n. The rnd sent
+ as argument must be initialized. Returns FALSE if the random number
+ could not be generated. Returns the generated value into `x' pointer
+ sent as argument, unless the `x' is NULL. The returned `x' must no be
+ freed by the caller. */
+int silc_dh_generate_private(SilcDH dh, SilcInt **x);
+
+/* Computes the public key y = g ^ x mod p, and returns it to the `y'
+ pointer sent as argument, unless the `y' is NULL. Returns FALSE if
+ the computation could not be performed. The returned `y' must not be
+ freed by the caller. */
+int silc_dh_compute_public(SilcDH dh, SilcInt **y);
+
+/* Sets the remote end's public value y' into the DH context. This must be
+ done before computing the secret key. Returns FALSE on error. */
+int silc_dh_set_remote_public(SilcDH dh, SilcInt **y);
+
+/* Computes the secret key z = y' ^ x mod p, and returns the key to the
+ `z' pointer sent as argument, unless the `z' is NULL. Returns FALSE if
+ the computation could not be performed. The returned `z' must not be
+ freed by the caller. */
+int silc_dh_compute_key(SilcDH dh, SilcInt **z);
+
+/* Same as above but returns the computed secret key as octet binary
+ string. */
+int silc_dh_compute_key_data(SilcDH dh, unsigned char **z,
+ unsigned int *z_len);
+
+#endif