2008-04-30 16:46:09

by Kevin Coffman

[permalink] [raw]
Subject: [enctypes round 2: PATCH 04/26] gss_krb5: Use random value to initialize confounder

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 <[email protected]>
---

net/sunrpc/auth_gss/gss_krb5_wrap.c | 22 ++++++++++++++++++----
1 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/net/sunrpc/auth_gss/gss_krb5_wrap.c b/net/sunrpc/auth_gss/gss_krb5_wrap.c
index e809571..a0660f5 100644
--- a/net/sunrpc/auth_gss/gss_krb5_wrap.c
+++ b/net/sunrpc/auth_gss/gss_krb5_wrap.c
@@ -87,8 +87,8 @@ out:
return 0;
}

-static inline void
-make_confounder(char *p, int blocksize)
+static void
+make_confounder(char *p, u32 conflen)
{
static u64 i = 0;
u64 *q = (u64 *)p;
@@ -102,8 +102,22 @@ 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();
+ }
+
+ switch (conflen) {
+ case 16:
+ *q++ = i++;
+ /* fall through */
+ case 8:
+ *q++ = i++;
+ break;
+ default:
+ BUG();
+ }
}

/* Assumptions: the head and tail of inbuf are ours to play with.