Merge pull request #200 from jhrozek/conf_prefix

Make the environment variable prefix configurable

README.md

@@ -253,6 +253,11 @@ MellonDiagnosticsEnable Off
         # Default. None set.
         MellonSetEnvNoPrefix "DISPLAY_NAME" "displayName"
 
+        # MellonEnvPrefix changes the string the variables passed from the
+        # IdP are prefixed with.
+        # Default: MELLON_
+        MellonEnvPrefix "NOLLEM_"
+
         # MellonMergeEnvVars merges multiple values of environment variables
         # set using MellonSetEnv into single variable:
         # ie: MYENV_VAR => val1;val2;val3 instead of default behaviour of:

auth_mellon.h

@@ -237,6 +237,7 @@ typedef struct am_dir_cfg_rec {
     am_samesite_t cookie_samesite;
     apr_array_header_t *cond;
     apr_hash_t *envattr;
+    const char *env_prefix;
     const char *userattr;
     const char *idpattr;
     LassoSignatureMethod signature_method;

auth_mellon_cache.c

@@ -589,7 +589,7 @@ void am_cache_env_populate(request_rec *r, am_cache_entry_t *t)
      */
     for(i = 0; i < t->size; ++i) {
         varname = am_cache_entry_get_string(t, &t->env[i].varname);
-        varname_prefix = "MELLON_";
+        varname_prefix = d->env_prefix;
 
         /* Check if we should map this name into another name. */
         env_varname_conf = (am_envattr_conf_t *)apr_hash_get(

auth_mellon_config.c

@@ -36,6 +36,11 @@ static const char *default_endpoint_path = "/mellon/";
  */
 static const char *default_user_attribute = "NAME_ID";
 
+/* This is the default prefix to use for attributes received from the
+ * server. Customizable using the MellonEnvPrefix option
+ */
+static const char *default_env_prefix = "MELLON_";
+
 /* This is the default name of the cookie which mod_auth_mellon will set.
  * If you change this, then you should also update the description of the
  * MellonVar configuration directive.
@@ -1372,8 +1377,10 @@ const command_rec auth_mellon_commands[] = {
         am_set_setenv_slot,
         NULL,
         OR_AUTHCFG,
-        "Renames attributes received from the server while retaining prefix MELLON_. The format is"
-        " MellonSetEnv <old name> <new name>."
+        "Renames attributes received from the server while retaining the"
+        " prefix. The prefix defaults to MELLON_ but can be changed with"
+        " MellonEnvPrefix."
+        " The format is MellonSetEnv <old name> <new name>."
         ),
      AP_INIT_TAKE2(
         "MellonSetEnvNoPrefix",
@@ -1383,6 +1390,13 @@ const command_rec auth_mellon_commands[] = {
         "Renames attributes received from the server without adding prefix. The format is"
         " MellonSetEnvNoPrefix <old name> <new name>."
         ),
+    AP_INIT_TAKE1(
+        "MellonEnvPrefix",
+        ap_set_string_slot,
+        (void *)APR_OFFSETOF(am_dir_cfg_rec, env_prefix),
+        OR_AUTHCFG,
+        "The prefix to use for attributes received from the server."
+        ),
     AP_INIT_FLAG(
         "MellonSessionDump",
         ap_set_flag_slot,
@@ -1714,6 +1728,7 @@ void *auth_mellon_dir_config(apr_pool_t *p, char *d)
     dir->cookie_path = NULL;
     dir->cookie_samesite = am_samesite_default;
     dir->envattr   = apr_hash_make(p);
+    dir->env_prefix = default_env_prefix;
     dir->userattr  = default_user_attribute;
     dir->idpattr  = NULL;
     dir->signature_method = inherit_signature_method;
@@ -1868,6 +1883,10 @@ void *auth_mellon_dir_merge(apr_pool_t *p, void *base, void *add)
                                      add_cfg->envattr :
                                      base_cfg->envattr);
 
+    new_cfg->env_prefix = (add_cfg->env_prefix != default_env_prefix ?
+                           add_cfg->env_prefix :
+                           base_cfg->env_prefix);
+
     new_cfg->userattr = (add_cfg->userattr != default_user_attribute ?
                          add_cfg->userattr :
                          base_cfg->userattr);

auth_mellon_diagnostics.c

@@ -442,6 +442,9 @@ am_diag_log_dir_cfg(request_rec *r, int level, am_dir_cfg_rec *cfg,
                     "%sMellonCookieSameSite (cookie_samesite): %s\n",
                     indent(level+1),
                     am_diag_samesite_str(r, cfg->cookie_samesite));
+    apr_file_printf(diag_cfg->fd,
+                    "%sMellonEnvPrefix (env_prefix): %s\n",
+                    indent(level+1), cfg->env_prefix);
 
     apr_file_printf(diag_cfg->fd,
                     "%sMellonCond (cond): %d items\n",
@@ -466,7 +469,7 @@ am_diag_log_dir_cfg(request_rec *r, int level, am_dir_cfg_rec *cfg,
         apr_hash_this(hash_item, (void *)&key, NULL, (void *)&envattr_conf);
 
         if (envattr_conf->prefixed) {
-            name = apr_pstrcat(r->pool, "MELLON_",
+            name = apr_pstrcat(r->pool, cfg->env_prefix,
                                envattr_conf->name, NULL);
         } else {
             name = envattr_conf->name;

doc/user_guide/mellon_user_guide.adoc

@@ -2007,11 +2007,13 @@ attributes.
   assertion to a name of your choosing when it is placed in the Apache
   environment. This is controlled by `MellonSetEnv` and
   `MellonSetEnvNoPrefix` directives.  The distinction
-  is `MellonSetEnv` always prepends the `MELLON_` prefix to the
+  is `MellonSetEnv` always prepends a prefix to the
   environment variable name to help to prevent name collisions. The
+  prefix defaults to `MELLON_` and can be configured using the
+  `MellonEnvPrefix` configuration option. The
   `MellonSetEnvNoPrefix` directive also remaps the assertion name to a
   name of your choosing but it omits prepending the environment
-  variable name with `MELLON_`. See <<map_assertion_attr_name>>
+  variable name with the prefix. See <<map_assertion_attr_name>>
 
 Using the <<assertion_response,assertion example>> Mellon places these
 environment variables in the Apache environment. See
@@ -2096,10 +2098,12 @@ and `MellonSetEnvNoPrefix` directives. These allow you to rename an
 assertion attribute to a name of your choosing. The `MellonSetEnv`
 directive follows the same convention as all other assertion
 attributes added by Mellon in that it always prefixes the environment
-variable name with `MELLON_` to help avoid name collisions in the
+variable name with a configurable prefix, which defaults to `MELLON_` to help avoid name collisions in the
 Apache environment. However sometimes you do not want the `MELLON_`
-prefix added and instead you want to use exactly the environment
-variable name as specified., `MellonSetEnvNoPrefix` serves this role.
+prefix added. In case you simply want the variables prefixed with
+a different string, use the `MellonEnvPrefix` configuration option. If,
+instead you want to use exactly the environment variable name as specified.,
+`MellonSetEnvNoPrefix` serves this role.
 
 To illustrate let's look at an example. Suppose your web app is
 expecting an attribute which is the user's last name, specifically it
@@ -2117,6 +2121,15 @@ MellonSetEnvNoPrefix REMOTE_USER_LASTNAME sn
 Also see <<set_remote_user>> for an example of setting the `REMOTE_USER`
 environment variable using `MellonSetEnvNoPrefix`.
 
+The `MellonEnvPrefix` variable might be useful e.g. if you
+are migrating from a different SP which used its own prefix
+for the variables passed by the IdP. For example, to prefix
+all variables with `NOLLEM_` you would use:
+
+----
+MellonEnvPrefix NOLLEM_
+----
+
 If you recieved an attribute-map.xml from your IDP that uses the
 `urn:mace:shibboleth:2.0:attribute-map` namespace, it can be converted
 to `MellonSetEnvNoPrefix` entries with `docs/mellon-attribute-map.xsl`