From 5af7fea571868eed16655adffcc9314911e12417 Mon Sep 17 00:00:00 2001
From: Lukas Slebodnik <lslebodn@redhat.com>
Date: Mon, 20 Oct 2014 22:21:25 +0200
Subject: [PATCH 75/87] PAM: Remove authtok from PAM stack with OTP

We remove the password from the PAM stack when OTP is used to make sure
that other pam modules (pam-gnome-keyring, pam_mount) cannot use it anymore
and have to request a password on their own.

Resolves:
    https://fedorahosted.org/sssd/ticket/2287

Reviewed-by: Nathaniel McCallum <npmccallum@redhat.com>
---
 src/providers/krb5/krb5_auth.c | 14 ++++++++++++++
 src/sss_client/pam_sss.c       | 16 +++++++++++++++-
 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/src/providers/krb5/krb5_auth.c b/src/providers/krb5/krb5_auth.c
index f539d5068ec29f7b06f734a3417864b43122b1b7..c96b7aee99da8c3d43a67a04bb1f67ee048d4705 100644
--- a/src/providers/krb5/krb5_auth.c
+++ b/src/providers/krb5/krb5_auth.c
@@ -1161,6 +1161,20 @@ static void krb5_auth_done(struct tevent_req *subreq)
         krb5_auth_store_creds(state->domain, pd);
     }
 
+    if (res->otp == true && pd->cmd == SSS_PAM_AUTHENTICATE) {
+        uint32_t otp_flag = 1;
+        ret = pam_add_response(pd, SSS_OTP, sizeof(uint32_t),
+                               (const uint8_t *) &otp_flag);
+        if (ret != EOK) {
+            DEBUG(SSSDBG_CRIT_FAILURE,
+                  "pam_add_response failed: %d (%s).\n",
+                  ret, sss_strerror(ret));
+            state->pam_status = PAM_SYSTEM_ERR;
+            state->dp_err = DP_ERR_OK;
+            goto done;
+        }
+    }
+
     state->pam_status = PAM_SUCCESS;
     state->dp_err = DP_ERR_OK;
     ret = EOK;
diff --git a/src/sss_client/pam_sss.c b/src/sss_client/pam_sss.c
index abe9b05478cbf480b3430dccd1951e9bfb0e29c1..d64e826daeb80be8998ef3b410047e3a44051b07 100644
--- a/src/sss_client/pam_sss.c
+++ b/src/sss_client/pam_sss.c
@@ -206,7 +206,7 @@ static size_t add_string_item(enum pam_item_type type, const char *str,
     return rp;
 }
 
-static void overwrite_and_free_pam_items(struct pam_items *pi)
+static void overwrite_and_free_authtoks(struct pam_items *pi)
 {
     if (pi->pam_authtok != NULL) {
         _pam_overwrite_n((void *)pi->pam_authtok, pi->pam_authtok_size);
@@ -222,6 +222,11 @@ static void overwrite_and_free_pam_items(struct pam_items *pi)
 
     pi->pamstack_authtok = NULL;
     pi->pamstack_oldauthtok = NULL;
+}
+
+static void overwrite_and_free_pam_items(struct pam_items *pi)
+{
+    overwrite_and_free_authtoks(pi);
 
     free(pi->domain_name);
     pi->domain_name = NULL;
@@ -998,6 +1003,15 @@ static int eval_response(pam_handle_t *pamh, size_t buflen, uint8_t *buf,
                     D(("do_pam_conversation failed."));
                 }
                 break;
+            case SSS_OTP:
+                D(("OTP was used, removing authtokens."));
+                overwrite_and_free_authtoks(pi);
+                ret = pam_set_item(pamh, PAM_AUTHTOK, NULL);
+                if (ret != PAM_SUCCESS) {
+                    D(("Failed to remove PAM_AUTHTOK after using otp [%s]",
+                       pam_strerror(pamh,ret)));
+                }
+                break;
             default:
                 D(("Unknown response type [%d]", type));
         }
-- 
1.9.3