Remove the support for insecure protocols in RMCP+

The two supported Cipher suites for RMCP+ will be cipher Suite 3
and 17 after this change. The cipher suite 3 is the default choice
for the ipmitool if the cipher suite is not explicitly mentioned.

The supported algorithms are the following:

Authentication: a) RAKP-HMAC-SHA1, b) RAKP-HMAC-SHA256
Integrity: a) HMAC-SHA1-9, b) HMAC-SHA256-128
Confidentiality: a) AES-CBC-128

Change-Id: Ia2fbaae29235e4bd43c42b59a2295a2db28efce3
Signed-off-by: Tom Joseph <tomjoseph@in.ibm.com>
diff --git a/integrity_algo.hpp b/integrity_algo.hpp
index 81f7da7..3d56b82 100644
--- a/integrity_algo.hpp
+++ b/integrity_algo.hpp
@@ -17,15 +17,16 @@
  * contents for the AuthCode “signature” field that accompanies authenticated
  * IPMI v2.0/RMCP+ messages once the session has been established. If the
  * Integrity Algorithm is none the AuthCode value is not calculated and the
- * AuthCode field in the message is not present.
+ * AuthCode field in the message is not present. Based on security
+ * recommendations NONE will not be supported.
  */
 enum class Algorithms : uint8_t
 {
-    NONE,                  // Mandatory
-    HMAC_SHA1_96,          // Mandatory
-    HMAC_MD5_128,          // Optional
-    MD5_128,               // Optional
-    HMAC_SHA256_128,       // Optional
+    NONE,            // Mandatory (implemented, not supported)
+    HMAC_SHA1_96,    // Mandatory (implemented, default choice in ipmitool)
+    HMAC_MD5_128,    // Optional (not implemented)
+    MD5_128,         // Optional (not implemented)
+    HMAC_SHA256_128, // Optional (implemented, best available)
 };
 
 /**
@@ -90,8 +91,7 @@
          */
         static bool isAlgorithmSupported(Algorithms algo)
         {
-            if (algo == Algorithms::NONE ||
-                algo == Algorithms::HMAC_SHA1_96 ||
+            if (algo == Algorithms::HMAC_SHA1_96 ||
                 algo == Algorithms::HMAC_SHA256_128)
             {
                return true;