[client:client.internal] implemented 'rescue(y1, y2) error' for extracting response data + rescuing key

src/git.xdrm.io/schastsp/client/client.internal.go

@@ -267,3 +267,38 @@ func (c *T) generateRequest(x1 []byte, x2 []byte) error {
 
 	return nil;
 }
+
+
+
+/* (5) Rescue management
+*
+* @Y1<[]byte>						First rescue parameter
+* @Y2<[]byte>						Second rescue parameter
+*
+* @return err<error>				The error or NIL if not
+*
+---------------------------------------------------------*/
+func (c *T) rescue(y1 []byte, y2 []byte) error {
+
+	/* (1) Extract time mod */
+	timeMod := uint32( xor.ByteArray(y1, y2)[0] % 2 )
+
+	/* (2) Try to guess time id from timeM */
+	timeId := timeid.Guess(c.ctx.Window(), timeMod);
+	var timeIdBytes []byte;
+	binary.BigEndian.PutUint32(timeIdBytes, timeId)
+
+	/* (3) Hash timeId */
+	hashedTimeId, err := scha.Hash(timeIdBytes, 1, nil, nil);
+	if err != nil { return err }
+
+	/* (4) Get the received hash */
+	receivedHash := xor.ByteArray(y1, hashedTimeId);
+
+	/* (4) Try to rescue the key */
+	err = c.key.Rescue(receivedHash)
+
+	/* (5) Dispatch error */
+	return err
+
+}