X-Git-Url: https://git.distorted.org.uk/~mdw/secnet/blobdiff_plain/1ce2f8bc69bc1bef98b48f450081d96e2c29cc00..5b5f297f9a9d47ee7e9804d5bdaa552f1953c6b6:/magic.h

diff --git a/magic.h b/magic.h
index 3ae7af4..e98f681 100644
--- a/magic.h
+++ b/magic.h
@@ -3,20 +3,46 @@
 #ifndef magic_h
 #define magic_h
 
-#define LABEL_NAK  0x00000000
-#define LABEL_MSG0 0x00020200
-#define LABEL_MSG1 0x01010101
-#define LABEL_MSG2 0x02020202
-#define LABEL_MSG3 0x03030303
-#define LABEL_MSG4 0x04040404
-#define LABEL_MSG5 0x05050505
-#define LABEL_MSG6 0x06060606
-#define LABEL_MSG7 0x07070707
-#define LABEL_MSG8 0x08080808
-#define LABEL_MSG9 0x09090909
+#define LABEL_NAK     0x00000000
+#define LABEL_MSG0    0x00020200
+#define LABEL_MSG1    0x01010101
+#define LABEL_MSG2    0x02020202
+#define LABEL_MSG3    0x03030303
+#define LABEL_MSG3BIS 0x13030313
+#define LABEL_MSG4    0x04040404
+#define LABEL_MSG5    0x05050505
+#define LABEL_MSG6    0x06060606
+#define LABEL_MSG7    0x07070707
+#define LABEL_MSG8    0x08080808
+#define LABEL_MSG9    0x09090909
 
 /* uses of the 32-bit capability bitmap */
-/* no flags currently defined */
-#define CAPAB_EARLY 0x00000000 /* no Early flags defined (see NOTES) */
+#define CAPAB_EARLY           0x00000000 /* no Early flags yet (see NOTES) */
+#define CAPAB_TRANSFORM_MASK  0x0000ffff
+/* remaining 16 bits are unused */
+
+/*
+ * The transform capability mask is a set of bits, one for each
+ * transform supported.  The transform capability numbers are set in
+ * the configuration (and should correspond between the two sites),
+ * although there are sensible defaults.
+ *
+ * Advertising a nonzero transform capability mask promises that
+ * the receiver understands LABEL_MSG3BIS messages, which
+ * contain an additional byte specifying the transform capability
+ * number actually chosen by the MSG3 sender.
+ *
+ * Aside from that, an empty bitmask is treated the same as
+ *  1u<<CAPAB_TRANSFORMNUM_ANCIENT
+ */
+
+/* bit indices, 0 is ls bit */
+#define CAPAB_TRANSFORMNUM_USER_MIN              0
+#define CAPAB_TRANSFORMNUM_USER_MAX              7
+#define CAPAB_TRANSFORMNUM_SERPENT256CBC         8
+#define CAPAB_TRANSFORMNUM_EAXSERPENT            9
+#define CAPAB_TRANSFORMNUM_MAX                  15
+
+#define CAPAB_TRANSFORMNUM_ANCIENT CAPAB_TRANSFORMNUM_SERPENT256CBC
 
 #endif /* magic_h */