Allocate new keys at server startup.

This avoids a potential race condition if the first 2 request come in at the
same time. It also avoids issues with forked apapche processes which may end
up with different keys per fork.

Signed-off-by: Simo Sorce <simo@redhat.com>

4 files changed, 44 insertions, 39 deletions

diff --git a/src/mod_auth_gssapi.c b/src/mod_auth_gssapi.c
index d4e2682..6f185f9 100644
--- a/src/mod_auth_gssapi.c
+++ b/src/mod_auth_gssapi.c
@@ -621,21 +621,30 @@ done:
 
 struct mag_req_cfg *mag_init_cfg(request_rec *req)
 {
+    struct mag_server_config *scfg;
     struct mag_req_cfg *req_cfg = apr_pcalloc(req->pool,
                                               sizeof(struct mag_req_cfg));
+    req_cfg->req = req;
     req_cfg->cfg = ap_get_module_config(req->per_dir_config,
                                         &auth_gssapi_module);
 
+    scfg = ap_get_module_config(req->server->module_config,
+                                &auth_gssapi_module);
+
     if (req_cfg->cfg->allowed_mechs) {
         req_cfg->desired_mechs = req_cfg->cfg->allowed_mechs;
     } else {
-        struct mag_server_config *scfg;
-        /* Try to fetch the default set if not explicitly configured */
-        scfg = ap_get_module_config(req->server->module_config,
-                                    &auth_gssapi_module);
+        /* Use the default set if not explicitly configured */
         req_cfg->desired_mechs = scfg->default_mechs;
     }
 
+    if (!req_cfg->cfg->mag_skey) {
+        req_cfg->mag_skey = req_cfg->cfg->mag_skey;
+    } else {
+        /* Use server random key if not explicitly configured */
+        req_cfg->mag_skey = scfg->mag_skey;
+    }
+
     if (req->proxyreq == PROXYREQ_PROXY) {
         req_cfg->req_proto = "Proxy-Authorization";
         req_cfg->rep_proto = "Proxy-Authenticate";
@@ -743,7 +752,7 @@ static int mag_auth(request_rec *req)
 
     /* if available, session always supersedes connection bound data */
     if (req_cfg->use_sessions) {
-        mag_check_session(req, cfg, &mc);
+        mag_check_session(req_cfg, &mc);
     }
 
     auth_header = apr_table_get(req->headers_in, req_cfg->req_proto);
@@ -802,7 +811,7 @@ static int mag_auth(request_rec *req)
         ba_pwd.length = strlen(ba_pwd.value);
 
         if (mc && mc->established &&
-            mag_basic_check(cfg, mc, ba_user, ba_pwd)) {
+            mag_basic_check(req_cfg, mc, ba_user, ba_pwd)) {
             ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, req,
                           "Already established BASIC AUTH context found!");
             mag_set_req_data(req, cfg, mc);
@@ -947,10 +956,10 @@ complete:
         mc->expiration = expiration;
         mc->auth_type = auth_type;
         if (auth_type == AUTH_TYPE_BASIC) {
-            mag_basic_cache(cfg, mc, ba_user, ba_pwd);
+            mag_basic_cache(req_cfg, mc, ba_user, ba_pwd);
         }
         if (req_cfg->use_sessions) {
-            mag_attempt_session(req, cfg, mc);
+            mag_attempt_session(req_cfg, mc);
         }
     }
 
@@ -1265,6 +1274,7 @@ static void *mag_create_server_config(apr_pool_t *p, server_rec *s)
 {
     struct mag_server_config *scfg;
     uint32_t maj, min;
+    apr_status_t rc;
 
     scfg = apr_pcalloc(p, sizeof(struct mag_server_config));
 
@@ -1278,6 +1288,12 @@ static void *mag_create_server_config(apr_pool_t *p, server_rec *s)
                                   mag_oid_set_destroy, apr_pool_cleanup_null);
     }
 
+    rc = SEAL_KEY_CREATE(p, &scfg->mag_skey, NULL);
+    if (rc != OK) {
+        ap_log_error(APLOG_MARK, APLOG_ERR, 0, s,
+                     "Failed to generate random sealing key!");
+    }
+
     return scfg;
 }
 
diff --git a/src/mod_auth_gssapi.h b/src/mod_auth_gssapi.h
index 46e5c6a..b08c38a 100644
--- a/src/mod_auth_gssapi.h
+++ b/src/mod_auth_gssapi.h
@@ -63,15 +63,18 @@ struct mag_config {
 
 struct mag_server_config {
     gss_OID_set default_mechs;
+    struct seal_key *mag_skey;
 };
 
 struct mag_req_cfg {
+    request_rec *req;
     struct mag_config *cfg;
     gss_OID_set desired_mechs;
     bool use_sessions;
     bool send_persist;
     const char *req_proto;
     const char *rep_proto;
+    struct seal_key *mag_skey;
 };
 
 struct mag_conn {
diff --git a/src/sessions.c b/src/sessions.c
index 73d600c..70f39a2 100644
--- a/src/sessions.c
+++ b/src/sessions.c
@@ -86,9 +86,9 @@ static GSSSessionData_t *decode_GSSSessionData(void *buf, size_t len)
 
 #define MAG_BEARER_KEY "MagBearerToken"
 
-void mag_check_session(request_rec *req,
-                       struct mag_config *cfg, struct mag_conn **conn)
+void mag_check_session(struct mag_req_cfg *cfg, struct mag_conn **conn)
 {
+    request_rec *req = cfg->req;
     struct mag_conn *mc;
     apr_status_t rc;
     session_rec *sess = NULL;
@@ -184,9 +184,9 @@ done:
     ASN_STRUCT_FREE(asn_DEF_GSSSessionData, gsessdata);
 }
 
-void mag_attempt_session(request_rec *req,
-                         struct mag_config *cfg, struct mag_conn *mc)
+void mag_attempt_session(struct mag_req_cfg *cfg, struct mag_conn *mc)
 {
+    request_rec *req = cfg->req;
     session_rec *sess = NULL;
     struct databuf plainbuf = { 0 };
     struct databuf cipherbuf = { 0 };
@@ -207,13 +207,8 @@ void mag_attempt_session(request_rec *req,
 
     if (!cfg->mag_skey) {
         ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, req,
-                      "Session key not available, generating new one.");
-        rc = SEAL_KEY_CREATE(cfg->pool, &cfg->mag_skey, NULL);
-        if (rc != OK) {
-            ap_log_rerror(APLOG_MARK, APLOG_ERR|APLOG_NOERRNO, 0, req,
-                          "Failed to create sealing key!");
-            return;
-        }
+                      "Session key not available, aborting.");
+        return;
     }
 
     gsessdata.established = mc->established?1:0;
@@ -275,25 +270,18 @@ static int mag_basic_hmac(struct seal_key *key, unsigned char *mac,
     return HMAC_BUFFER(key, &databuf, &hmacbuf);
 }
 
-static int mag_get_mac_size(struct mag_config *cfg)
+static int mag_get_mac_size(struct mag_req_cfg *cfg)
 {
-    apr_status_t rc;
-
     if (!cfg->mag_skey) {
-        ap_log_perror(APLOG_MARK, APLOG_INFO, 0, cfg->pool,
-                      "Session key not available, generating new one.");
-        rc = SEAL_KEY_CREATE(cfg->pool, &cfg->mag_skey, NULL);
-        if (rc != OK) {
-            ap_log_perror(APLOG_MARK, APLOG_ERR|APLOG_NOERRNO, 0, cfg->pool,
-                          "Failed to create sealing key!");
-            return 0;
-        }
+        ap_log_perror(APLOG_MARK, APLOG_INFO, 0, cfg->cfg->pool,
+                      "Session key not available, aborting!");
+        return 0;
     }
 
     return get_mac_size(cfg->mag_skey);
 }
 
-bool mag_basic_check(struct mag_config *cfg, struct mag_conn *mc,
+bool mag_basic_check(struct mag_req_cfg *cfg, struct mag_conn *mc,
                      gss_buffer_desc user, gss_buffer_desc pwd)
 {
     int mac_size = mag_get_mac_size(cfg);
@@ -320,7 +308,7 @@ done:
     return res;
 }
 
-void mag_basic_cache(struct mag_config *cfg, struct mag_conn *mc,
+void mag_basic_cache(struct mag_req_cfg *cfg, struct mag_conn *mc,
                      gss_buffer_desc user, gss_buffer_desc pwd)
 {
     int mac_size = mag_get_mac_size(cfg);
diff --git a/src/sessions.h b/src/sessions.h
index 840dbe9..be6ff16 100644
--- a/src/sessions.h
+++ b/src/sessions.h
@@ -1,14 +1,12 @@
 /* Copyright (C) 2014 mod_auth_gssapi authors - See COPYING for (C) terms */
 
-struct mag_config;
+struct mag_req_cfg;
 struct mag_conn;
 
 void mag_post_config_session(void);
-void mag_check_session(request_rec *req,
-                       struct mag_config *cfg, struct mag_conn **conn);
-void mag_attempt_session(request_rec *req,
-                         struct mag_config *cfg, struct mag_conn *mc);
-bool mag_basic_check(struct mag_config *cfg, struct mag_conn *mc,
+void mag_check_session(struct mag_req_cfg *cfg, struct mag_conn **conn);
+void mag_attempt_session(struct mag_req_cfg *cfg, struct mag_conn *mc);
+bool mag_basic_check(struct mag_req_cfg *cfg, struct mag_conn *mc,
                      gss_buffer_desc user, gss_buffer_desc pwd);
-void mag_basic_cache(struct mag_config *cfg, struct mag_conn *mc,
+void mag_basic_cache(struct mag_req_cfg *cfg, struct mag_conn *mc,
                      gss_buffer_desc user, gss_buffer_desc pwd);