Implement the axlotl ratchet

3 files changed, 29 insertions, 5 deletions

diff --git a/include/axolotl/axolotl.hh b/include/axolotl/axolotl.hh
index 34280d4..ead52fc 100644
--- a/include/axolotl/axolotl.hh
+++ b/include/axolotl/axolotl.hh
@@ -1,6 +1,6 @@
 
-#include "axololt/crypto.hh"
-#include "axololt/list.hh"
+#include "axolotl/crypto.hh"
+#include "axolotl/list.hh"
 
 namespace axolotl {
 
@@ -52,7 +52,10 @@ enum struct ErrorCode {
 static std::size_t const MAX_RECEIVER_CHAINS = 5;
 static std::size_t const MAX_SKIPPED_MESSAGE_KEYS = 40;
 
+
 struct KdfInfo {
+    std::uint8_t const * root_info;
+    std::size_t root_info_length;
     std::uint8_t const * ratchet_info;
     std::size_t ratchet_info_length;
     std::uint8_t const * message_info;
@@ -61,15 +64,30 @@ struct KdfInfo {
 
 
 struct Session {
+
+    Session(
+        KdfInfo const & kdf_info
+    );
+
     /** A pair of string to feed into the KDF identifing the application */
     KdfInfo kdf_info;
     /** The last error that happened encypting or decrypting a message */
     ErrorCode last_error;
     SharedKey root_key;
     List<SenderChain, 1> sender_chain;
-    List<ReceiverChain, MAX_RECEIVER_CHAINS> reciever_chains;
+    List<ReceiverChain, MAX_RECEIVER_CHAINS> receiver_chains;
     List<SkippedMessageKey, MAX_SKIPPED_MESSAGE_KEYS> skipped_message_keys;
 
+    void initialise_as_bob(
+        std::uint8_t const * shared_secret, std::size_t shared_secret_length,
+        Curve25519PublicKey const & their_ratchet_key
+    );
+
+    void initialise_as_alice(
+        std::uint8_t const * shared_secret, std::size_t shared_secret_length,
+        Curve25519KeyPair const & our_ratchet_key
+    );
+
     std::size_t encrypt_max_output_length(
         std::size_t plaintext_length
     );
diff --git a/include/axolotl/crypto.hh b/include/axolotl/crypto.hh
index 42c154b..f1e81ac 100644
--- a/include/axolotl/crypto.hh
+++ b/include/axolotl/crypto.hh
@@ -15,8 +15,9 @@ struct Curve25519KeyPair : public Curve25519PublicKey {
 };
 
 
-Curve25519KeyPair generate_key(
-    std::uint8_t const * random_32_bytes
+void generate_key(
+    std::uint8_t const * random_32_bytes,
+    Curve25519KeyPair & key_pair
 );
 
 
diff --git a/include/axolotl/list.hh b/include/axolotl/list.hh
index a3c3d01..4c87630 100644
--- a/include/axolotl/list.hh
+++ b/include/axolotl/list.hh
@@ -61,6 +61,11 @@ public:
     }
 
     /**
+     * Make space for an item in the list at the start of the list
+     */
+    T * insert() { return insert(begin()); }
+
+    /**
      * Insert an item into the list at a given position.
      * If inserting the item makes the list longer than max_size then
      * the end of the list is discarded.