start with brandt.c

brandt.c

@@ -22,8 +22,62 @@
 #include <gcrypt.h>
 
 #include "crypto.h"
+#include "internals.h"
 #include "util.h"
 
+
+typedef int
+(*msg_recv)(struct BRANDT_Auction *ad,
+            const unsigned char   *buf,
+            size_t                buflen,
+            uint16_t              sender);
+
+
+/**
+ * stores the function pointers to receive functions for each state.
+ *
+ * The first index denotes if a first price auction or a M+1st price auction is
+ * used. If it is 0, it is a first price auction, if it is 1, it is a M+1st
+ * price auction.
+ *
+ * The second index denotes if the outcome should be public or private. A value
+ * of 0 means a private outcome, while a value of 1 means public outcome.
+ */
+static msg_recv handler_in[2][2][msg_last] =
+{
+	[0] =
+	{
+		[0] =
+		{
+			[msg_init] = smc_recv_keyshare,
+			[msg_bid] = smc_recv_encrypted_bid,
+			[msg_outcome] = fp_priv_recv_outcome,
+			[msg_decrypt] = fp_priv_recv_decryption,
+		},
+		[1] =
+		{
+			[msg_init] = smc_recv_keyshare,
+			[msg_bid] = smc_recv_encrypted_bid,
+			[msg_outcome] = fp_pub_recv_outcome,
+			[msg_decrypt] = fp_pub_recv_decryption,
+		}
+	},
+	[1] =
+	{
+		[0] =
+		{
+			[msg_init] = smc_recv_keyshare,
+			[msg_bid] = smc_recv_encrypted_bid,
+		},
+		[1] =
+		{
+			[msg_init] = smc_recv_keyshare,
+			[msg_bid] = smc_recv_encrypted_bid,
+		}
+	}
+};
+
+
 void
 BRANDT_init ()
 {
@@ -37,7 +91,7 @@ BRANDT_init ()
 		weprintf ("failed to set libgcrypt option DISABLE_SECMEM: %s",
 		          gcry_strerror (err));
 
-	/* ecc is slow otherwise. */
+	/* ecc is slow otherwise and we don't create long term keys anyway. */
 	if ((err = gcry_control (GCRYCTL_ENABLE_QUICK_RANDOM, 0)))
 		weprintf ("failed to set libgcrypt option ENABLE_QUICK_RANDOM: %s",
 		          gcry_strerror (err));
@@ -45,3 +99,29 @@ BRANDT_init ()
 	gcry_control (GCRYCTL_INITIALIZATION_FINISHED, 0);
 	brandt_crypto_init ();
 }
+
+
+void
+BRANDT_got_message (struct BRANDT_Auction *auction,
+                    uint16_t              sender,
+                    const unsigned char   *msg,
+                    size_t                msg_len)
+{
+	uint16_t    type = *(uint16_t *)msg;
+	int         m = !!auction->desc->m;
+	int         pub = !!auction->desc->outcome_public;
+	enum rounds round = auction->cur_round;
+
+	/** todo: cache out of order messages */
+
+	if (!handler_in[m][pub][round] ||
+	    !handler_in[m][pub][round](auction,
+	                               msg + sizeof (type),
+	                               msg_len - sizeof (type),
+	                               sender))
+	{
+		/** \todo */
+		weprintf ("wow fail");
+	}
+	msg + sizeof (type);
+}

brandt.h

@@ -23,19 +23,16 @@
 #ifndef _BRANDT_BRANDT_H
 #define _BRANDT_BRANDT_H
 
-#include <unistd.h>
 #include <stdint.h>
+#include <unistd.h>
 
-/**
+/** defined in internals.h */
- * \todo.
- */
 struct BRANDT_Auction;
 
 /**
  * Functions of this type are called by libbrandt to broadcast messages to the
- * blackboard of a specific auction.
+ * blackboard of a specific auction. They have to be sent using authenticated
- *
+ * encryption.
- * \todo: how must the message be handled? (encryption, auth, reliability, …)
  *
  * @param[in] auction_closure Closure pointer representing the respective
  * auction. This is the Pointer given to BRANDT_join().
@@ -45,16 +42,15 @@ struct BRANDT_Auction;
  * @return 0 on success, -1 on failure.
  */
 typedef int
-(*BRANDT_BroadcastCallback)(void *      auction_closure,
+(*BRANDT_CbBroadcast)(void       *auction_closure,
                       const void *msg,
                       size_t     msg_len);
 
 
 /**
  * Functions of this type are called by libbrandt to unicast messages to the
- * seller of a specific auction.
+ * seller of a specific auction. They have to be sent using authenticated
- *
+ * encryption.
- * \todo: how must the message be handled? (encryption, auth, reliability, …)
  *
  * @param[in] auction_closure Closure pointer representing the respective
  * auction. This is the Pointer given to BRANDT_join().
@@ -63,7 +59,7 @@ typedef int
  * @return 0 on success, -1 on failure.
  */
 typedef int
-(*BRANDT_UnicastSellerCallback)(void *      auction_closure,
+(*BRANDT_CbUnicast)(void       *auction_closure,
                     const void *msg,
                     size_t     msg_len);
 
@@ -72,7 +68,6 @@ typedef int
  * Functions of this type are called by libbrandt to report the auction outcome
  * or malicious/erroneous participants.
  *
- * \todo: update price type.
  * \todo: export proof of erroneous behaviour.
  *
  * @param[in] auction_closure Closure pointer representing the respective
@@ -84,7 +79,7 @@ typedef int
  * is private and the user did not win.
  */
 typedef void
-(*BRANDT_ReportResultCallback)(void *       auction_closure,
+(*BRANDT_CbResult)(void         *auction_closure,
                    unsigned int bidder_id,
                    int          status,
                    uint16_t     price);
@@ -98,7 +93,7 @@ BRANDT_init ();
  *
  * @param[in] broadcast Pointer to the broadcast callback function
  * @param[in] unicast Pointer to the unicast callback function
- * @param[in] report Pointer to the report callback function
+ * @param[in] result Pointer to the result callback function
  * @param[in] auction_closure Closure pointer representing the auction. This
  * will not be touched by libbrandt. It is only passed to the callbacks.
  * @param[in] auction_data The auction information data a an opaque data
@@ -110,9 +105,9 @@ BRANDT_init ();
  * black-box pointer, do NOT access/change it or the data it points to!
  */
 struct BRANDT_Auction *
-BRANDT_join (BRANDT_BroadcastCallback     broadcast,
+BRANDT_join (BRANDT_CbBroadcast broadcast,
-             BRANDT_UnicastSellerCallback unicast,
+             BRANDT_CbUnicast   unicast,
-             BRANDT_ReportResultCallback  report,
+             BRANDT_CbResult    result,
              const void         *auction_closure,
              const void         *auction_data,
              size_t             auction_data_len);
@@ -132,7 +127,7 @@ BRANDT_join (BRANDT_BroadcastCallback     broadcast,
  * Create a new auction described by the @a auction_data parameter.
  *
  * @param[in] broadcast Pointer to the broadcast callback function
- * @param[in] report Pointer to the report callback function
+ * @param[in] result Pointer to the result callback function
  * @param[in] auction_closure Closure pointer representing the auction. This
  * will not be touched by libbrandt. It is only passed to the callbacks.
  * @param[out] auction_data The auction information data a an opaque data
@@ -155,44 +150,34 @@ BRANDT_join (BRANDT_BroadcastCallback     broadcast,
  * black-box pointer, do NOT access/change it or the data it points to!
  */
 struct BRANDT_Auction *
-BRANDT_new (BRANDT_BroadcastCallback    broadcast,
+BRANDT_new (BRANDT_CbBroadcast broadcast,
-            BRANDT_ReportResultCallback report,
+            BRANDT_CbResult    result,
-            const void *                auction_closure,
+            void               *auction_closure,
-            const void **               auction_data,
+            void               **auction_data,
             size_t             *auction_data_len,
             uint16_t           num_prices,
             uint16_t           m,
             int                outcome_public);
 
 
+/** \todo */
+void
+BRANDT_free ();
+
+
 /**
- * Receive a broadcast message related to a specific auction.
+ * Receive a message related to a specific auction.
  *
  * @param[in] auction The pointer returned by BRANDT_join() or BRANDT_new() from
  * which message @a msg was received.
+ * @param[in] sender The id of the sender.
  * @param[in] msg The message that was received.
  * @param[in] msg_len The length in bytes of @a msg.
  */
 void
-BRANDT_got_broadcast (struct BRANDT_Auction *auction,
+BRANDT_got_message (struct BRANDT_Auction *auction,
-                      void *                 msg,
+                    uint16_t              sender,
-                      size_t                 msg_len);
+                    const unsigned char   *msg,
-
-
-/**
- * Receive a unicast message from a bidder related to a specific auction.
- *
- * @param[in] auction The pointer returned by BRANDT_new() from which message
- * @a msg was received.
- * @param[in] msg The message that was received.
- * @param[in] msg_len The length in bytes of @a msg.
- * \todo: how to link message to sender id within auction?
- * ANSWER: on start, know that we have 'n' participants, here give
- *         participant number (1..n)
- */
-void
-BRANDT_got_unicast (struct BRANDT_Auction *auction,
-                    void *                 msg,
                     size_t                msg_len);
 
 

internals.h

@@ -25,7 +25,50 @@
 
 #include <gcrypt.h>
 
-struct AuctionData {
+#include "brandt.h"
+
+
+enum rounds {
+	msg_init,
+	msg_bid,
+	msg_outcome,
+	msg_decrypt,
+	msg_last
+};
+
+
+/**
+ * This struct describes an auction and has to be followed by #description_len
+ * bytes of arbitrary data where the description of the item to be sold is
+ * stored. */
+struct AuctionDescr {
+	/** The length of the description in bytes directly following this struct */
+	uint32_t description_len;
+
+	/** Auction type. 0 means first price Auction, >= 0 means M+1st price
+	 * auction with an amount of m items being sold. */
+	uint16_t m;
+
+	/** Outcome type. 0 means private outcome, everything else means public
+	 * outcome. */
+	uint16_t outcome_public;
+
+	/** The amount of possible prices */
+	uint16_t price_range;
+};
+
+
+struct BRANDT_Auction {
+	struct AuctionDescr *desc;  /** pointer to the auction information */
+
+	BRANDT_CbBroadcast bcast;   /** broadcast callback */
+	BRANDT_CbUnicast   ucast;   /** unicast callback */
+	BRANDT_CbResult    result;  /** result reporting callback */
+
+	int         seller_mode;    /** If 0 we are bidding, selling otherwise */
+	enum rounds cur_round;      /** The round we expect messages from */
+	gcry_mpi_t  round_progress; /** Stores which round messages were received */
+
 	uint16_t n;                 /** The amount of bidders/agents */
 	uint16_t k;                 /** The amount of possible prices */
 	uint16_t i;                 /** Own agents index, only used when bidding */
@@ -38,9 +81,15 @@ struct AuctionData {
 	gcry_mpi_point_t **alpha;   /** alphas, size: n*k */
 	gcry_mpi_point_t **beta;    /** betas, size: n*k */
 
-	gcry_mpi_point_t ***gamma; /** gamma, size: n*n*k */
+	gcry_mpi_point_t **gamma2;  /** gamma2, for public outcome, size: n*k */
-	gcry_mpi_point_t ***delta; /** delta, size: n*n*k */
+	gcry_mpi_point_t ***gamma3; /** gamma3, for private outcome, size: n*n*k */
-	gcry_mpi_point_t ***phi;   /** phi, size: n*n*k */
+	gcry_mpi_point_t **delta2;  /** delta2, for public outcome, size: n*k */
+	gcry_mpi_point_t ***delta3; /** delta3, for private outcome, size: n*n*k */
+	gcry_mpi_point_t **phi2;    /** phi2, for public outcome, size: n*k */
+	gcry_mpi_point_t ***phi3;   /** phi3, for private outcome, size: n*n*k */
+
+	gcry_mpi_point_t *tmpa1;    /** used for temporary storage, size: k */
+	gcry_mpi_point_t *tmpb1;    /** used for temporary storage, size: k */
 };
 
 #endif /* ifndef _BRANDT_INTERNALS_H */