Adding the toyclient implementation

toyclient.cc

@@ -0,0 +1,72 @@
+#include "pirclient.h"
+
+// This is a toy "private" (not really private) lookup protocol.
+// It is only here to show you how to implement a subclass of PIRClient.
+// Do not use this code for anything requiring actual privacy.
+//
+// The params are a random 32-byte string.  Lookups are done by
+// "encrypting" the lookup key by XORing it with the param string.
+// The reply is XORed with repeated copies of the same string.
+
+class ToyClient : public PIRClient {
+public:
+    ToyClient();
+
+    // Create a PIR query.  The plainquery must be exactly 32 bytes
+    // long.
+    virtual void create(const string &plainquery, const string &params,
+        void *&queryid, string &pirquery);
+
+    // Extract the plaintext response from a PIR response.  Returns
+    // true if successful, false if unsuccessful.
+    virtual bool extract(void *&queryid, const string &pirresponse,
+        string &plainresponse);
+};
+
+ToyClient::ToyClient()
+{
+}
+
+// Put anything you'll need to decrypt the response in here
+struct Decryptstate {
+    string decryptkey;
+};
+
+void
+ToyClient::create(const string &plainquery, const string &params,
+        void *&queryid, string &pirquery)
+{
+    if (plainquery.length() == 32 && params.length() == 32) {
+        pirquery.assign(plainquery);
+        for (size_t i=0;i<32;++i) {
+            pirquery[i] ^= params[i];
+        }
+        Decryptstate *ds = new Decryptstate();
+        ds->decryptkey.assign(params);
+        queryid = ds;
+    }
+}
+
+bool
+ToyClient::extract(void *&queryid, const string &pirresponse,
+        string &plainresponse)
+{
+    Decryptstate *ds = (Decryptstate *)queryid;
+    size_t response_size = pirresponse.length();
+    plainresponse.assign(pirresponse);
+    for(size_t i=0;i<response_size;++i) {
+        plainresponse[i] ^= ds->decryptkey[i % 32];
+    }
+    delete ds;
+    queryid = NULL;
+
+    return true;
+}
+
+int main(int argc, char **argv) {
+    ToyClient client;
+
+    client.mainloop();
+
+    return 0;
+}