Prepare for adding RMCP+ cipher suite 17
In many places, there are baked-in assumptions about algorithms that tie
the session initiation to cipher suite 3. This commit teases out those
assumptions and prepares for the next patch that actually adds in the
new authentication and integrity algorithms to support cipher suite 17.
Change-Id: I2ee3672a7c503b89c5ff0aba30cf7a4601e24d04
Signed-off-by: Vernon Mauery <vernon.mauery@linux.intel.com>
diff --git a/rmcp.hpp b/rmcp.hpp
new file mode 100644
index 0000000..fd536cb
--- /dev/null
+++ b/rmcp.hpp
@@ -0,0 +1,39 @@
+#pragma once
+
+#include <array>
+#include <cstdint>
+
+namespace rmcp
+{
+
+/*
+ * RSP needs more keying material than can be provided by session
+ * integrity key alone. As a result all keying material for the RSP
+ * confidentiality algorithms will be generated by processing a
+ * pre-defined set of constants using HMAC per [RFC2104], keyed by SIK.
+ * These constants are constructed using a hexadecimal octet value
+ * repeated up to the HMAC block size in length starting with the
+ * constant 01h. This mechanism can be used to derive up to 255
+ * HMAC-block-length pieces of keying material from a single SIK.For the
+ * mandatory confidentiality algorithm AES-CBC-128, processing the
+ * following constant will generate the required amount of keying
+ * material.
+ */
+constexpr size_t CONST_N_SIZE = 20;
+using Const_n = std::array<uint8_t, CONST_N_SIZE>;
+
+static constexpr Const_n const_1 = {
+ 0x01, 0x01, 0x01, 0x01, 0x01,
+ 0x01, 0x01, 0x01, 0x01, 0x01,
+ 0x01, 0x01, 0x01, 0x01, 0x01,
+ 0x01, 0x01, 0x01, 0x01, 0x01
+};
+
+static constexpr Const_n const_2 = {
+ 0x02, 0x02, 0x02, 0x02, 0x02,
+ 0x02, 0x02, 0x02, 0x02, 0x02,
+ 0x02, 0x02, 0x02, 0x02, 0x02,
+ 0x02, 0x02, 0x02, 0x02, 0x02
+};
+
+} // namespace rmcp