Improvements for LDAP Password Policy support

Display warnings about remaining grace logins and password
expiration to the user, when LDAP Password Policies are used.

Improved detection if LDAP Password policies are supported by
LDAP Server.

6 files changed, 201 insertions, 20 deletions

diff --git a/src/providers/ldap/ldap_auth.c b/src/providers/ldap/ldap_auth.c
index 52287030..8c77e3aa 100644
--- a/src/providers/ldap/ldap_auth.c
+++ b/src/providers/ldap/ldap_auth.c
@@ -7,6 +7,7 @@
         Sumit Bose <sbose@redhat.com>
 
     Copyright (C) 2008 Red Hat
+    Copyright (C) 2010, rhafer@suse.de, Novell Inc.
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -135,6 +136,39 @@ static errno_t check_pwexpire_shadow(struct spwd *spwd, time_t now,
     return EOK;
 }
 
+static errno_t check_pwexpire_ldap(struct pam_data *pd,
+                                   struct sdap_ppolicy_data *ppolicy,
+                                   enum sdap_result *result)
+{
+    if (ppolicy->grace > 0 || ppolicy->expire > 0) {
+        uint32_t *data;
+        uint32_t *ptr;
+
+        data = talloc_size(pd, 2* sizeof(uint32_t));
+        if (data == NULL) {
+            DEBUG(1, ("talloc_size failed.\n"));
+            return ENOMEM;
+        }
+
+        ptr = data;
+        if (ppolicy->grace > 0) {
+            *ptr = SSS_PAM_USER_INFO_GRACE_LOGIN;
+            ptr++;
+            *ptr = ppolicy->grace;
+        } else if (ppolicy->expire > 0) {
+            *ptr = SSS_PAM_USER_INFO_EXPIRE_WARN;
+            ptr++;
+            *ptr = ppolicy->expire;
+        }
+
+        pam_add_response(pd, SSS_PAM_USER_INFO, 2* sizeof(uint32_t),
+                         (uint8_t*)data);
+    }
+
+    *result = SDAP_AUTH_SUCCESS;
+    return EOK;
+}
+
 static errno_t string_to_shadowpw_days(const char *s, long *d)
 {
     long l;
@@ -569,8 +603,15 @@ static void auth_bind_user_done(struct tevent_req *subreq)
     struct auth_state *state = tevent_req_data(req,
                                                     struct auth_state);
     int ret;
-
-    ret = sdap_auth_recv(subreq, &state->result);
+    struct sdap_ppolicy_data *ppolicy;
+
+    ret = sdap_auth_recv(subreq, state, &state->result, &ppolicy);
+    if (ppolicy != NULL) {
+        DEBUG(9,("Found ppolicy data, "
+                 "assuming LDAP password policies are active.\n"));
+        state->pw_expire_type = PWEXPIRE_LDAP_PASSWORD_POLICY;
+        state->pw_expire_data = ppolicy;
+    }
     talloc_zfree(subreq);
     if (ret) {
         tevent_req_error(req, ret);
@@ -960,6 +1001,13 @@ static void sdap_pam_auth_done(struct tevent_req *req)
                 }
                 break;
             case PWEXPIRE_LDAP_PASSWORD_POLICY:
+                ret = check_pwexpire_ldap(state->pd, pw_expire_data, &result);
+                if (ret != EOK) {
+                    DEBUG(1, ("check_pwexpire_ldap failed.\n"));
+                    state->pd->pam_status = PAM_SYSTEM_ERR;
+                    goto done;
+                }
+                break;
             case PWEXPIRE_NONE:
                 break;
             default:
diff --git a/src/providers/ldap/sdap.h b/src/providers/ldap/sdap.h
index 007185fc..f0e345ec 100644
--- a/src/providers/ldap/sdap.h
+++ b/src/providers/ldap/sdap.h
@@ -85,6 +85,11 @@ struct sdap_service {
     char *uri;
 };
 
+struct sdap_ppolicy_data {
+    int grace;
+    int expire;
+};
+
 #define SYSDB_SHADOWPW_LASTCHANGE "shadowLastChange"
 #define SYSDB_SHADOWPW_MIN "shadowMin"
 #define SYSDB_SHADOWPW_MAX "shadowMax"
diff --git a/src/providers/ldap/sdap_async.h b/src/providers/ldap/sdap_async.h
index 3c52d236..888df6b4 100644
--- a/src/providers/ldap/sdap_async.h
+++ b/src/providers/ldap/sdap_async.h
@@ -76,7 +76,11 @@ struct tevent_req *sdap_auth_send(TALLOC_CTX *memctx,
                                   const char *user_dn,
                                   const char *authtok_type,
                                   struct dp_opt_blob authtok);
-int sdap_auth_recv(struct tevent_req *req, enum sdap_result *result);
+
+int sdap_auth_recv(struct tevent_req *req,
+                   TALLOC_CTX *memctx,
+                   enum sdap_result *result,
+                   struct sdap_ppolicy_data **ppolicy);
 
 struct tevent_req *sdap_get_initgr_send(TALLOC_CTX *memctx,
                                         struct tevent_context *ev,
diff --git a/src/providers/ldap/sdap_async_connection.c b/src/providers/ldap/sdap_async_connection.c
index 586733f4..f8c69569 100644
--- a/src/providers/ldap/sdap_async_connection.c
+++ b/src/providers/ldap/sdap_async_connection.c
@@ -4,6 +4,7 @@
     Async LDAP Helper routines
 
     Copyright (C) Simo Sorce <ssorce@redhat.com> - 2009
+    Copyright (C) 2010, rhafer@suse.de, Novell Inc.
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -278,6 +279,7 @@ struct simple_bind_state {
     struct sdap_op *op;
 
     struct sdap_msg *reply;
+    struct sdap_ppolicy_data *ppolicy;
     int result;
 };
 
@@ -401,6 +403,7 @@ static void simple_bind_done(struct sdap_op *op,
 
     if (response_controls == NULL) {
         DEBUG(5, ("Server returned no controls.\n"));
+        state->ppolicy = NULL;
     } else {
         for (c = 0; response_controls[c] != NULL; c++) {
             DEBUG(9, ("Server returned control [%s].\n",
@@ -420,12 +423,30 @@ static void simple_bind_done(struct sdap_op *op,
                 DEBUG(7, ("Password Policy Response: expire [%d] grace [%d] "
                           "error [%s].\n", pp_expire, pp_grace,
                           ldap_passwordpolicy_err2txt(pp_error)));
-
-                if ((state->result == LDAP_SUCCESS &&
-                        (pp_error == PP_changeAfterReset || pp_grace > 0)) ||
-                    (state->result == LDAP_INVALID_CREDENTIALS &&
-                        pp_error == PP_passwordExpired ) ) {
-                    DEBUG(4, ("User must set a new password.\n"));
+                state->ppolicy = talloc(state, struct sdap_ppolicy_data);
+                if (state->ppolicy == NULL) {
+                    DEBUG(1, ("talloc failed.\n"));
+                    ret = ENOMEM;
+                    goto done;
+                }
+                state->ppolicy->grace = pp_grace;
+                state->ppolicy->expire = pp_expire;
+                if (state->result == LDAP_SUCCESS) {
+                    if (pp_error == PP_changeAfterReset) {
+                        DEBUG(4, ("Password was reset. "
+                                  "User must set a new password.\n"));
+                        state->result = LDAP_X_SSSD_PASSWORD_EXPIRED;
+                    } else if (pp_grace > 0) {
+                        DEBUG(4, ("Password expired. "
+                                  "[%d] grace logins remaining.\n", pp_grace));
+                    } else if (pp_expire > 0) {
+                        DEBUG(4, ("Password will expire in [%d] seconds.\n",
+                                  pp_expire));
+                    }
+                } else if (state->result == LDAP_INVALID_CREDENTIALS &&
+                           pp_error == PP_passwordExpired) {
+                    DEBUG(4,
+                          ("Password expired user must set a new password.\n"));
                     state->result = LDAP_X_SSSD_PASSWORD_EXPIRED;
                 }
             }
@@ -446,7 +467,10 @@ done:
     }
 }
 
-static int simple_bind_recv(struct tevent_req *req, int *ldaperr)
+static int simple_bind_recv(struct tevent_req *req,
+                            TALLOC_CTX *memctx,
+                            int *ldaperr,
+                            struct sdap_ppolicy_data **ppolicy)
 {
     struct simple_bind_state *state = tevent_req_data(req,
                                             struct simple_bind_state);
@@ -455,6 +479,7 @@ static int simple_bind_recv(struct tevent_req *req, int *ldaperr)
     TEVENT_REQ_RETURN_ON_ERROR(req);
 
     *ldaperr = state->result;
+    *ppolicy = talloc_steal(memctx, state->ppolicy);
     return EOK;
 }
 
@@ -704,6 +729,7 @@ int sdap_kinit_recv(struct tevent_req *req, enum sdap_result *result)
 struct sdap_auth_state {
     const char *user_dn;
     struct berval pw;
+    struct sdap_ppolicy_data *ppolicy;
 
     int result;
     bool is_sasl;
@@ -766,8 +792,9 @@ static void sdap_auth_done(struct tevent_req *subreq)
 
     if (state->is_sasl) {
         ret = sasl_bind_recv(subreq, &state->result);
+        state->ppolicy = NULL;
     } else {
-        ret = simple_bind_recv(subreq, &state->result);
+        ret = simple_bind_recv(subreq, state, &state->result, &state->ppolicy);
     }
     if (ret != EOK) {
         tevent_req_error(req, ret);
@@ -777,7 +804,10 @@ static void sdap_auth_done(struct tevent_req *subreq)
     tevent_req_done(req);
 }
 
-int sdap_auth_recv(struct tevent_req *req, enum sdap_result *result)
+int sdap_auth_recv(struct tevent_req *req,
+                   TALLOC_CTX *memctx,
+                   enum sdap_result *result,
+                   struct sdap_ppolicy_data **ppolicy)
 {
     struct sdap_auth_state *state = tevent_req_data(req,
                                                  struct sdap_auth_state);
@@ -785,6 +815,9 @@ int sdap_auth_recv(struct tevent_req *req, enum sdap_result *result)
     *result = SDAP_ERROR;
     TEVENT_REQ_RETURN_ON_ERROR(req);
 
+    if (ppolicy != NULL) {
+        *ppolicy = talloc_steal(memctx, state->ppolicy);
+    }
     switch (state->result) {
         case LDAP_SUCCESS:
             *result = SDAP_AUTH_SUCCESS;
@@ -1078,7 +1111,7 @@ static void sdap_cli_auth_done(struct tevent_req *subreq)
     enum sdap_result result;
     int ret;
 
-    ret = sdap_auth_recv(subreq, &result);
+    ret = sdap_auth_recv(subreq, NULL, &result, NULL);
     talloc_zfree(subreq);
     if (ret) {
         tevent_req_error(req, ret);
diff --git a/src/sss_client/pam_sss.c b/src/sss_client/pam_sss.c
index 2ba6f158..07ed4e72 100644
--- a/src/sss_client/pam_sss.c
+++ b/src/sss_client/pam_sss.c
@@ -3,6 +3,7 @@
         Sumit Bose <sbose@redhat.com>
 
     Copyright (C) 2009 Red Hat
+    Copyright (C) 2010, rhafer@suse.de, Novell Inc.
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU Lesser General Public License as published by
@@ -436,6 +437,81 @@ static int user_info_offline_auth(pam_handle_t *pamh, size_t buflen,
     return PAM_SUCCESS;
 }
 
+static int user_info_grace_login(pam_handle_t *pamh,
+                                 size_t buflen,
+                                 uint8_t *buf)
+{
+    int ret;
+    uint32_t grace;
+    char user_msg[256];
+
+    if (buflen != 2* sizeof(uint32_t)) {
+        D(("User info response data has the wrong size"));
+        return PAM_BUF_ERR;
+    }
+    memcpy(&grace, buf + sizeof(uint32_t), sizeof(uint32_t));
+    ret = snprintf(user_msg, sizeof(user_msg),
+                   _("Your password has expired. "
+                     "You have %d grace login(s) remaining."),
+                   grace);
+    if (ret < 0 || ret >= sizeof(user_msg)) {
+        D(("snprintf failed."));
+        return PAM_SYSTEM_ERR;
+    }
+    ret = do_pam_conversation(pamh, PAM_TEXT_INFO, user_msg, NULL, NULL);
+
+    if (ret != PAM_SUCCESS) {
+        D(("do_pam_conversation failed."));
+        return PAM_SYSTEM_ERR;
+    }
+
+    return PAM_SUCCESS;
+}
+
+#define MINSEC 60
+#define HOURSEC (60*MINSEC)
+#define DAYSEC (24*HOURSEC)
+static int user_info_expire_warn(pam_handle_t *pamh,
+                                 size_t buflen,
+                                 uint8_t *buf)
+{
+    int ret;
+    uint32_t expire;
+    char user_msg[256];
+    const char* unit="second(s)";
+
+    if (buflen != 2* sizeof(uint32_t)) {
+        D(("User info response data has the wrong size"));
+        return PAM_BUF_ERR;
+    }
+    memcpy(&expire, buf + sizeof(uint32_t), sizeof(uint32_t));
+    if (expire >= DAYSEC) {
+        expire /= DAYSEC;
+        unit = "day(s)";
+    } else if (expire >= HOURSEC) {
+        expire /= HOURSEC;
+        unit = "hour(s)";
+    } else if (expire >= MINSEC) {
+        expire /= MINSEC;
+        unit = "minute(s)";
+    }
+
+    ret = snprintf(user_msg, sizeof(user_msg),
+                   _("Your password will expire in %d %s."), expire, unit);
+    if (ret < 0 || ret >= sizeof(user_msg)) {
+        D(("snprintf failed."));
+        return PAM_SYSTEM_ERR;
+    }
+    ret = do_pam_conversation(pamh, PAM_TEXT_INFO, user_msg, NULL, NULL);
+
+    if (ret != PAM_SUCCESS) {
+        D(("do_pam_conversation failed."));
+        return PAM_SYSTEM_ERR;
+    }
+
+    return PAM_SUCCESS;
+}
+
 static int user_info_offline_auth_delayed(pam_handle_t *pamh, size_t buflen,
                                   uint8_t *buf)
 {
@@ -563,6 +639,12 @@ static int eval_user_info_response(pam_handle_t *pamh, size_t buflen,
         case SSS_PAM_USER_INFO_OFFLINE_AUTH:
             ret = user_info_offline_auth(pamh, buflen, buf);
             break;
+        case SSS_PAM_USER_INFO_GRACE_LOGIN:
+            ret = user_info_grace_login(pamh, buflen, buf);
+            break;
+        case SSS_PAM_USER_INFO_EXPIRE_WARN:
+            ret = user_info_expire_warn(pamh, buflen, buf);
+            break;
         case SSS_PAM_USER_INFO_OFFLINE_AUTH_DELAYED:
             ret = user_info_offline_auth_delayed(pamh, buflen, buf);
             break;
diff --git a/src/sss_client/sss_cli.h b/src/sss_client/sss_cli.h
index 2edd158d..f3872657 100644
--- a/src/sss_client/sss_cli.h
+++ b/src/sss_client/sss_cli.h
@@ -377,13 +377,22 @@ enum user_info_type {
                                        * possible to change the password while
                                        * the system is offline. This message
                                        * is generated by the PAM responder. */
-    SSS_PAM_USER_INFO_CHPASS_ERROR /**< Tell the user that a password change
-                                    * failed and optionally give a reason.
-                                    * @param Size of the message as unsigned
-                                    * 32-bit integer value. A value of 0
-                                    * indicates that no message is following.
-                                    * @param String with the specified
-                                    * length. */
+    SSS_PAM_USER_INFO_CHPASS_ERROR, /**< Tell the user that a password change
+                                     * failed and optionally give a reason.
+                                     * @param Size of the message as unsigned
+                                     * 32-bit integer value. A value of 0
+                                     * indicates that no message is following.
+                                     * @param String with the specified
+                                     * length. */
+    SSS_PAM_USER_INFO_GRACE_LOGIN, /**< Warn the user that the password is
+                                    * expired and inform about the remaining
+                                    * number of grace logins.
+                                    * @param The number of remaining grace
+                                    * logins as uint32_t */
+    SSS_PAM_USER_INFO_EXPIRE_WARN /**< Warn the user that the password will
+                                   * expire soon.
+                                   * @param Number of seconds before the user's
+                                   * password will expire. */
 };
 /**
  * @}