1 files changed, 123 insertions, 0 deletions
diff --git a/comm/third_party/libotr/src/dh.h b/comm/third_party/libotr/src/dh.h
new file mode 100644
index 0000000000..742c408042
--- /dev/null
+++ b/comm/third_party/libotr/src/dh.h
@@ -0,0 +1,123 @@
+/*
+ *  Off-the-Record Messaging library
+ *  Copyright (C) 2004-2012  Ian Goldberg, Chris Alexander, Willy Lew,
+ *  			     Nikita Borisov
+ *                           <otr@cypherpunks.ca>
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of version 2.1 of the GNU Lesser General
+ *  Public License as published by the Free Software Foundation.
+ *
+ *  This library 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
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with this library; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef __DH_H__
+#define __DH_H__
+
+#define DH1536_GROUP_ID 5
+
+typedef struct {
+    unsigned int groupid;
+    gcry_mpi_t priv, pub;
+} DH_keypair;
+
+/* Which half of the secure session id should be shown in bold? */
+typedef enum {
+    OTRL_SESSIONID_FIRST_HALF_BOLD,
+    OTRL_SESSIONID_SECOND_HALF_BOLD
+} OtrlSessionIdHalf;
+
+#define OTRL_EXTRAKEY_BYTES 32
+
+typedef struct {
+    unsigned char sendctr[16];
+    unsigned char rcvctr[16];
+    gcry_cipher_hd_t sendenc;
+    gcry_cipher_hd_t rcvenc;
+    gcry_md_hd_t sendmac;
+    unsigned char sendmackey[20];
+    int sendmacused;
+    gcry_md_hd_t rcvmac;
+    unsigned char rcvmackey[20];
+    int rcvmacused;
+    unsigned char extrakey[OTRL_EXTRAKEY_BYTES];
+} DH_sesskeys;
+
+/*
+ * Call this once, at plugin load time.  It sets up the modulus and
+ * generator MPIs.
+ */
+void otrl_dh_init(void);
+
+/*
+ * Initialize the fields of a DH keypair.
+ */
+void otrl_dh_keypair_init(DH_keypair *kp);
+
+/*
+ * Copy a DH_keypair.
+ */
+void otrl_dh_keypair_copy(DH_keypair *dst, const DH_keypair *src);
+
+/*
+ * Deallocate the contents of a DH_keypair (but not the DH_keypair
+ * itself)
+ */
+void otrl_dh_keypair_free(DH_keypair *kp);
+
+/*
+ * Generate a DH keypair for a specified group.
+ */
+gcry_error_t otrl_dh_gen_keypair(unsigned int groupid, DH_keypair *kp);
+
+/*
+ * Construct session keys from a DH keypair and someone else's public
+ * key.
+ */
+gcry_error_t otrl_dh_session(DH_sesskeys *sess, const DH_keypair *kp,
+	gcry_mpi_t y);
+
+/*
+ * Compute the secure session id, two encryption keys, and four MAC keys
+ * given our DH key and their DH public key.
+ */
+gcry_error_t otrl_dh_compute_v2_auth_keys(const DH_keypair *our_dh,
+	gcry_mpi_t their_pub, unsigned char *sessionid, size_t *sessionidlenp,
+	gcry_cipher_hd_t *enc_c, gcry_cipher_hd_t *enc_cp,
+	gcry_md_hd_t *mac_m1, gcry_md_hd_t *mac_m1p,
+	gcry_md_hd_t *mac_m2, gcry_md_hd_t *mac_m2p);
+
+/*
+ * Compute the secure session id, given our DH key and their DH public
+ * key.
+ */
+gcry_error_t otrl_dh_compute_v1_session_id(const DH_keypair *our_dh,
+	gcry_mpi_t their_pub, unsigned char *sessionid, size_t *sessionidlenp,
+	OtrlSessionIdHalf *halfp);
+
+/*
+ * Deallocate the contents of a DH_sesskeys (but not the DH_sesskeys
+ * itself)
+ */
+void otrl_dh_session_free(DH_sesskeys *sess);
+
+/*
+ * Blank out the contents of a DH_sesskeys (without releasing it)
+ */
+void otrl_dh_session_blank(DH_sesskeys *sess);
+
+/* Increment the top half of a counter block */
+void otrl_dh_incctr(unsigned char *ctr);
+
+/* Compare two counter values (8 bytes each).  Return 0 if ctr1 == ctr2,
+ * < 0 if ctr1 < ctr2 (as unsigned 64-bit values), > 0 if ctr1 > ctr2. */
+int otrl_dh_cmpctr(const unsigned char *ctr1, const unsigned char *ctr2);
+
+#endif