Document upgrading principals to AES

[wiki.git] / doc / root-instance.mdwn

diff --git a/doc/root-instance.mdwn b/doc/root-instance.mdwn
index 777bfed8e8694a786ac690fec4a3e91d103c0e9b..1747d67a7fcf309479812984c22080ca711d7fbc 100644 (file)
--- a/doc/root-instance.mdwn
+++ b/doc/root-instance.mdwn
@@ -68,7 +68,7 @@ have developed shell scripts to make it easy to switch between them.
    use syntax like "krbroot ssh linerva" when you want to use your
    root instance for a command. You can also "krbroot shell".
 
- * quentin has [kdo](http://web.mit.edu/quentin/Public/mac-bashrc),
+ * quentin and broder wrote [kdo](http://web.mit.edu/snippets/kerberos/kdo),
    which is similar in spirit to krbroot, but designed for Mac OS
    X. It takes advantage of the fact that OS X's Kerberos
    implementation is better at handling multiple tickets.
@@ -100,9 +100,25 @@ extra instance's password instead.
 
 ## Getting them
 
-You need to show up in person to IS&T User Accounts in N42 with a
+You need to show up in person to [IS&T User
+Accounts](http://ist.mit.edu/support/accounts) in
+[E17](http://whereis.mit.edu/?go=E17) during business hours with a
 photo ID to obtain new Kerberos identities. For the reasons described
 above, being in control of your null instance and sending a zephyr or
 authenticated e-mail with it does not mean that you can go ahead and
 make changes to your root or extra instance too.  While you're there,
 be sure to ask for a pts id, if you want to use your tickets with AFS.
+
+## Upgrading cryptographic strength
+
+You should change your root instance’s password with a command like this, to upgrade your key from critically weak DES encryption algorithm to strong AES encryption:
+
+    kadmin -p andersk/root -q 'cpw -e aes256-cts:normal andersk/root'
+
+(Note: This might make your password incompatible with a [handful of services](http://debathena.mit.edu/trac/ticket/529) that you should not have been using with your root instance in the first place.)  You can confirm the change with
+
+    kadmin -p andersk/root -q 'getprinc andersk/root'
+
+which should list a line like
+
+    Key: vno 4, aes256-cts-hmac-sha1-96, no salt