[ https://issues.apache.org/jira/browse/HADOOP-15235?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16370833#comment-16370833 ]
Hudson commented on HADOOP-15235: --------------------------------- SUCCESS: Integrated in Jenkins build Hadoop-trunk-Commit #13690 (See [https://builds.apache.org/job/Hadoop-trunk-Commit/13690/]) HADOOP-15235. Authentication Tokens should use HMAC instead of MAC (rkanter: rev 324e5a7cf2bdb6f93e7c6fd9023817528f243dcf) * (edit) hadoop-common-project/hadoop-auth/src/main/java/org/apache/hadoop/security/authentication/util/Signer.java > Authentication Tokens should use HMAC instead of MAC > ---------------------------------------------------- > > Key: HADOOP-15235 > URL: https://issues.apache.org/jira/browse/HADOOP-15235 > Project: Hadoop Common > Issue Type: Improvement > Components: security > Affects Versions: 2.10.0, 3.2.0 > Reporter: Robert Kanter > Assignee: Robert Kanter > Priority: Major > Fix For: 2.10.0, 3.2.0 > > Attachments: HADOOP-15235.001.patch, HADOOP-15235.002.patch > > > We currently use {{MessageDigest}} to compute a "SHA" MAC for signing > Authentication Tokens. Firstly, what "SHA" maps to is dependent on the JVM > and Cryptography Provider. While they _should_ do something reasonable, it's > probably a safer idea to pick a specific algorithm. It looks like the Oracle > JVM picks SHA-1; though something like SHA-256 would be better. > In any case, it would also be better to use an HMAC algorithm instead. > Changing from SHA-1 to SHA-256 or MAC to HMAC won't generate equivalent > signatures, so this would normally be an incompatible change because the > server wouldn't accept previous tokens it issued with the older algorithm. > However, Authentication Tokens are used as a cheaper shortcut for Kerberos, > so it's expected for users to also have Kerberos credentials; in this case, > the Authentication Token will be rejected, but it will silently retry using > Kerberos, and get an updated token. So this should all be transparent to the > user. > And finally, the code where we verify a signature uses a non-constant-time > comparison, which could be subject to timing attacks. I believe it would be > quite difficult in this case to do so, but we're probably better off using a > constant-time comparison. -- This message was sent by Atlassian JIRA (v7.6.3#76005) --------------------------------------------------------------------- To unsubscribe, e-mail: common-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: common-issues-h...@hadoop.apache.org