diff -up mod_auth_mellon-0.14.0/auth_mellon_cache.c.env_prefix mod_auth_mellon-0.14.0/auth_mellon_cache.c

--- mod_auth_mellon-0.14.0/auth_mellon_cache.c.env_prefix	2017-10-02 11:44:08.000000000 +0200

+++ mod_auth_mellon-0.14.0/auth_mellon_cache.c	2019-06-10 09:46:36.806014513 +0200

@@ -589,7 +589,7 @@ void am_cache_env_populate(request_rec *

      */

     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(

diff -up mod_auth_mellon-0.14.0/auth_mellon_config.c.env_prefix mod_auth_mellon-0.14.0/auth_mellon_config.c

--- mod_auth_mellon-0.14.0/auth_mellon_config.c.env_prefix	2018-03-16 08:14:54.000000000 +0100

+++ mod_auth_mellon-0.14.0/auth_mellon_config.c	2019-06-10 09:46:36.807014516 +0200

@@ -36,6 +36,11 @@ static const char *default_endpoint_path

  */

 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

     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 *

                                      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);

diff -up mod_auth_mellon-0.14.0/auth_mellon_diagnostics.c.env_prefix mod_auth_mellon-0.14.0/auth_mellon_diagnostics.c

--- mod_auth_mellon-0.14.0/auth_mellon_diagnostics.c.env_prefix	2018-03-16 08:14:54.000000000 +0100

+++ mod_auth_mellon-0.14.0/auth_mellon_diagnostics.c	2019-06-10 09:46:36.808014518 +0200

@@ -442,6 +442,9 @@ am_diag_log_dir_cfg(request_rec *r, int

                     "%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

         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;

diff -up mod_auth_mellon-0.14.0/auth_mellon.h.env_prefix mod_auth_mellon-0.14.0/auth_mellon.h

--- mod_auth_mellon-0.14.0/auth_mellon.h.env_prefix	2018-03-16 08:14:54.000000000 +0100

+++ mod_auth_mellon-0.14.0/auth_mellon.h	2019-06-10 09:46:36.805014510 +0200

@@ -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;

diff -up mod_auth_mellon-0.14.0/doc/user_guide/mellon_user_guide.adoc.env_prefix mod_auth_mellon-0.14.0/doc/user_guide/mellon_user_guide.adoc

--- mod_auth_mellon-0.14.0/doc/user_guide/mellon_user_guide.adoc.env_prefix	2018-03-16 08:14:54.000000000 +0100

+++ mod_auth_mellon-0.14.0/doc/user_guide/mellon_user_guide.adoc	2019-06-10 09:48:08.422237471 +0200

@@ -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. T

 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_LASTNAM

 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_

+----

+

 === Using Mellon to apply constraints [[assertion_constraints]]

 SAML attributes can be used for more than exporting those values to a

diff -up mod_auth_mellon-0.14.0/README.md.env_prefix mod_auth_mellon-0.14.0/README.md

--- mod_auth_mellon-0.14.0/README.md.env_prefix	2018-03-16 08:14:54.000000000 +0100

+++ mod_auth_mellon-0.14.0/README.md	2019-06-10 09:46:36.805014510 +0200

@@ -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: