[PATCH 07/28] gss_krb5: Use random value to initialize confounder

[Kevin Coffman]

Initialize the value used for the confounder to a random value
rather than starting from zero.
Allow for confounders of length 8 or 16 (which will be needed for AES).

Signed-off-by: Kevin Coffman <kwc at citi.umich.edu>
---

 net/sunrpc/auth_gss/gss_krb5_wrap.c |   17 ++++++++++++++---
 1 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/net/sunrpc/auth_gss/gss_krb5_wrap.c b/net/sunrpc/auth_gss/gss_krb5_wrap.c
index 3cd99a7..89338a4 100644
--- a/net/sunrpc/auth_gss/gss_krb5_wrap.c
+++ b/net/sunrpc/auth_gss/gss_krb5_wrap.c
@@ -88,7 +88,7 @@ out:
 }
 
 static inline void
-make_confounder(char *p, int blocksize)
+make_confounder(char *p, int conflen)
 {
 	static u64 i = 0;
 	u64 *q = (u64 *)p;
@@ -102,8 +102,19 @@ make_confounder(char *p, int blocksize)
 	 * uniqueness would mean worrying about atomicity and rollover, and I
 	 * don't care enough. */
 
-	BUG_ON(blocksize != 8);
-	*q = i++;
+	/* initialize to random value */
+	if (i == 0) {
+		i = random32();
+		i = (i << 32) | random32();
+	}
+
+	if (conflen == 8)
+		*q = i++;
+	else if (conflen == 16) {
+		*q++ = i++;
+		*q++ = i++;
+	} else
+		BUG();
 }
 
 /* Assumptions: the head and tail of inbuf are ours to play with.