diff options
| author | Nicholas Bellinger <nab@linux-iscsi.org> | 2014-06-05 18:08:57 -0700 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2014-07-11 13:33:47 +0100 |
| commit | 9ae0f3c0d18c443a72664577bdb70fe30f796b7d (patch) | |
| tree | 30dabd05d1eba045c2d6c2e72f538bdde7854069 | |
| parent | 4e53b9de24ecec036a8f6c8acae25e426a8bdab1 (diff) | |
| download | lwn-9ae0f3c0d18c443a72664577bdb70fe30f796b7d.tar.gz lwn-9ae0f3c0d18c443a72664577bdb70fe30f796b7d.zip | |
iscsi-target: Reject mutual authentication with reflected CHAP_C
commit 1d2b60a5545942b1376cb48c1d55843d71e3a08f upstream.
This patch adds an explicit check in chap_server_compute_md5() to ensure
the CHAP_C value received from the initiator during mutual authentication
does not match the original CHAP_C provided by the target.
This is in line with RFC-3720, section 8.2.1:
Originators MUST NOT reuse the CHAP challenge sent by the Responder
for the other direction of a bidirectional authentication.
Responders MUST check for this condition and close the iSCSI TCP
connection if it occurs.
Reported-by: Tejas Vaykole <tejas.vaykole@calsoftinc.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | drivers/target/iscsi/iscsi_target_auth.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/target/iscsi/iscsi_target_auth.c b/drivers/target/iscsi/iscsi_target_auth.c index 59e7378f66c6..32eb6b49c713 100644 --- a/drivers/target/iscsi/iscsi_target_auth.c +++ b/drivers/target/iscsi/iscsi_target_auth.c @@ -337,6 +337,16 @@ static int chap_server_compute_md5( goto out; } /* + * During mutual authentication, the CHAP_C generated by the + * initiator must not match the original CHAP_C generated by + * the target. + */ + if (!memcmp(challenge_binhex, chap->challenge, CHAP_CHALLENGE_LENGTH)) { + pr_err("initiator CHAP_C matches target CHAP_C, failing" + " login attempt\n"); + goto out; + } + /* * Generate CHAP_N and CHAP_R for mutual authentication. */ tfm = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC); |