Initial revision

6 files changed, 1141 insertions, 0 deletions

diff --git a/modules/pam_env/.cvsignore b/modules/pam_env/.cvsignore
new file mode 100644
index 00000000..380a834a
--- /dev/null
+++ b/modules/pam_env/.cvsignore
@@ -0,0 +1 @@
+dynamic
diff --git a/modules/pam_env/Makefile b/modules/pam_env/Makefile
new file mode 100644
index 00000000..e872d1ee
--- /dev/null
+++ b/modules/pam_env/Makefile
@@ -0,0 +1,111 @@
+#
+# $Id$
+#
+# This Makefile controls a build process of $(TITLE) module for
+# Linux-PAM. You should not modify this Makefile (unless you know
+# what you are doing!).
+#
+# $Log$
+# Revision 1.1  2000/06/20 22:11:33  agmorgan
+# Initial revision
+#
+# Revision 1.2  1999/10/09 05:08:28  morgan
+# removed libpwdb dependencies (libpwdb support is depreciated)
+#
+# Revision 1.1.1.1  1998/07/12 05:17:16  morgan
+# Linux PAM sources pre-0.66
+#
+# Revision 1.1  1997/04/05 06:42:35  morgan
+# Initial revision
+#
+# Revision 1.1  1997/01/04 20:32:52  morgan
+# Initial revision
+#
+# Created by Andrew Morgan <morgan@parc.power.net> 1996/12/8
+# Adaptations by Dave Kinclea and Cristian Gafton
+#
+
+TITLE=pam_env
+
+CONFD=$(CONFIGED)/security
+export CONFD
+CONFILE=$(CONFD)/pam_env.conf
+export CONFILE
+
+#
+
+LIBSRC = $(TITLE).c
+LIBOBJ = $(TITLE).o
+LIBOBJD = $(addprefix dynamic/,$(LIBOBJ))
+LIBOBJS = $(addprefix static/,$(LIBOBJ))
+
+ifdef DYNAMIC
+LIBSHARED = $(TITLE).so
+endif
+
+dynamic/%.o : %.c
+	$(CC) $(CFLAGS) $(DYNAMIC) $(CPPFLAGS) $(TARGET_ARCH) -c $< -o $@
+
+ifdef STATIC
+LIBSTATIC = lib$(TITLE).o
+endif
+
+static/%.o : %.c
+	$(CC) $(CFLAGS) $(STATIC) $(CPPFLAGS) $(TARGET_ARCH) -c $< -o $@
+
+####################### don't edit below #######################
+
+dummy:
+
+	@echo "**** This is not a top-level Makefile "
+	exit
+
+all: dirs $(LIBSHARED) $(LIBSTATIC) register
+
+dirs:
+ifdef DYNAMIC
+	$(MKDIR) ./dynamic
+endif
+ifdef STATIC
+	$(MKDIR) ./static
+endif
+
+register:
+ifdef STATIC
+	( cd .. ; ./register_static $(TITLE) $(TITLE)/$(LIBSTATIC) )
+endif
+
+ifdef DYNAMIC
+$(LIBOBJD): $(LIBSRC)
+
+$(LIBSHARED):	$(LIBOBJD)
+	$(LD_D) -o $@ $(LIBOBJD) $(EXTRALIB)
+endif
+
+ifdef STATIC
+$(LIBOBJS): $(LIBSRC)
+
+$(LIBSTATIC): $(LIBOBJS)
+	$(LD) -r -o $@ $(LIBOBJS) $(EXTRALIB)
+endif
+
+install: all
+ifdef DYNAMIC
+	$(MKDIR) $(FAKEROOT)$(SECUREDIR)
+	$(INSTALL) -m $(SHLIBMODE) $(LIBSHARED) $(FAKEROOT)$(SECUREDIR)
+endif
+	$(MKDIR) $(FAKEROOT)$(SCONFIGED)
+	bash -f ./install_conf
+
+remove:
+	rm -f $(FAKEROOT)$(SECUREDIR)/$(TITLE).so
+
+clean:
+	rm -f $(LIBOBJD) $(LIBOBJS) core *~
+
+extraclean: clean
+	rm -f *.a *.o *.so *.bak dynamic/* static/*
+
+.c.o:	
+	$(CC) $(CFLAGS) -c $<
+
diff --git a/modules/pam_env/README b/modules/pam_env/README
new file mode 100644
index 00000000..04df323b
--- /dev/null
+++ b/modules/pam_env/README
@@ -0,0 +1,72 @@
+# $Date$
+# $Author$
+# $Id$
+#
+# This is the configuration file for pam_env, a PAM module to load in 
+# a configurable list of environment variables for a 
+# 
+# The original idea for this came from Andrew G. Morgan ...
+#<quote>
+#   Mmm. Perhaps you might like to write a pam_env module that reads a
+#   default environment from a file? I can see that as REALLY
+#   useful... Note it would be an "auth" module that returns PAM_IGNORE
+#   for the auth part and sets the environment returning PAM_SUCCESS in
+#   the setcred function...
+#</quote>
+#
+# What I wanted was the REMOTEHOST variable set, purely for selfish
+# reasons, and AGM didn't want it added to the SimpleApps login
+# program (which is where I added the patch). So, my first concern is
+# that variable, from there there are numerous others that might/would
+# be useful to be set: NNTPSERVER, LESS, PATH, PAGER, MANPAGER .....
+#
+# Of course, these are a different kind of variable than REMOTEHOST in
+# that they are things that are likely to be configured by
+# administrators rather than set by logging in, how to treat them both
+# in the same config file?
+#
+# Here is my idea: 
+#
+# Each line starts with the variable name, there are then two possible
+# options for each variable DEFAULT and OVERRIDE. 
+# DEFAULT allows and administrator to set the value of the
+# variable  to some default value, if none is supplied then the empty
+# string is assumed. The OVERRIDE option tells pam_env that it should
+# enter in its value (overriding the default value) if there is one
+# to use. OVERRIDE is not used, "" is assumed and no override will be
+# done. 
+#
+# VARIABLE   [DEFAULT=[value]]  [OVERRIDE=[value]]
+#
+# (Possibly non-existent) environment variables may be used in values
+# using the ${string} syntax and (possibly non-existent) PAM_ITEMs may
+# be used in values using the @{string} syntax. Both the $ and @
+# characters can be backslash escaped to be used as literal values
+# values can be delimited with "", escaped " not supported.
+#
+#
+# First, some special variables
+#
+# Set the REMOTEHOST variable for any hosts that are remote, default
+# to "localhost" rather than not being set at all
+REMOTEHOST	DEFAULT=localhost OVERRIDE=@{PAM_RHOST}
+#
+# Set the DISPLAY variable if it seems reasonable 
+DISPLAY		DEFAULT=${REMOTEHOST}:0.0 OVERRIDE=${DISPLAY}
+#
+#
+#  Now some simple variables
+#
+PAGER		DEFAULT=less
+MANPAGER	DEFAULT=less
+LESS		DEFAULT="M q e h15 z23 b80"
+NNTPSERVER	DEFAULT=localhost
+PATH		DEFAULT=${HOME}/bin:/usr/local/bin:/bin\
+:/usr/bin:/usr/local/bin/X11:/usr/bin/X11
+#
+# silly examples of escaped variables, just to show how they work.
+#
+DOLLAR		DEFAULT=\$
+DOLLARDOLLAR	DEFAULT=	OVERRIDE=\$${DOLLAR}
+DOLLARPLUS	DEFAULT=\${REMOTEHOST}${REMOTEHOST}
+ATSIGN		DEFAULT=""	OVERRIDE=\@
diff --git a/modules/pam_env/install_conf b/modules/pam_env/install_conf
new file mode 100755
index 00000000..4c608400
--- /dev/null
+++ b/modules/pam_env/install_conf
@@ -0,0 +1,46 @@
+#!/bin/bash
+
+CONFILE=$FAKEROOT"$CONFILE"
+IGNORE_AGE=./.ignore_age
+QUIET_INSTALL=../../.quiet_install
+CONF=./pam_env.conf-example
+MODULE=pam_env
+
+echo
+
+if [ -f "$QUIET_INSTALL" ]; then
+    if [ ! -f "$CONFILE" ]; then
+        yes="y"
+    else
+        yes="skip"
+    fi
+elif [ -f "$IGNORE_AGE" ]; then
+    echo "you don't want to be bothered with the age of your $CONFILE file"
+    yes="n"
+elif [ ! -f "$CONFILE" ] || [ "$CONF" -nt "$CONFILE" ]; then
+    if [ -f "$CONFILE" ]; then
+	echo "An older $MODULE configuration file already exists ($CONFILE)"
+	echo "Do you wish to copy the $CONF file in this distribution"
+	echo "to $CONFILE ? (y/n) [skip] "
+        read yes
+    else
+	yes="y"
+    fi
+else
+    yes="skip"
+fi
+
+if [ "$yes" = "y" ]; then
+    mkdir -p $FAKEROOT$CONFD
+    echo "  copying $CONF to $CONFILE"
+    cp $CONF $CONFILE
+else
+    echo "  Skipping $CONF installation"
+    if [ "$yes" = "n" ]; then
+	touch "$IGNORE_AGE"
+    fi
+fi
+
+echo
+
+exit 0
diff --git a/modules/pam_env/pam_env.c b/modules/pam_env/pam_env.c
new file mode 100644
index 00000000..5ba89268
--- /dev/null
+++ b/modules/pam_env/pam_env.c
@@ -0,0 +1,839 @@
+/* pam_mail module */
+
+/*
+ * $Id$
+ *
+ * Written by Dave Kinchlea <kinch@kinch.ark.com> 1997/01/31
+ * Inspired by Andrew Morgan <morgan@parc.power.net, who also supplied the 
+ * template for this file (via pam_mail)
+ */
+
+#ifndef DEFAULT_CONF_FILE
+#define DEFAULT_CONF_FILE       "/etc/security/pam_env.conf"
+#endif
+
+#define DEFAULT_ETC_ENVFILE     "/etc/environment"
+#define DEFAULT_READ_ENVFILE    1
+
+#define _GNU_SOURCE
+#define _BSD_SOURCE
+
+#include <features.h>
+#include <ctype.h>
+#include <errno.h>
+#include <pwd.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <syslog.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+/*
+ * here, we make a definition for the externally accessible function
+ * in this file (this definition is required for static a module
+ * but strongly encouraged generally) it is used to instruct the
+ * modules include file to define the function prototypes.
+ */
+
+#define PAM_SM_AUTH         /* This is primarily a AUTH_SETCRED module */
+#define PAM_SM_SESSION      /* But I like to be friendly */
+#define PAM_SM_PASSWORD     /*        ""                 */
+#define PAM_SM_ACCOUNT      /*        ""                 */
+
+#include <security/pam_modules.h>
+#include <security/_pam_macros.h>
+
+/* This little structure makes it easier to keep variables together */
+
+typedef struct var {
+  char *name;
+  char *value;
+  char *defval;
+  char *override;
+} VAR;
+
+#define BUF_SIZE 1024
+#define MAX_ENV  8192
+
+#define GOOD_LINE    0
+#define BAD_LINE     100       /* This must be > the largest PAM_* error code */
+
+#define DEFINE_VAR   101     
+#define UNDEFINE_VAR 102
+#define ILLEGAL_VAR  103
+
+static int  _assemble_line(FILE *, char *, int);
+static int  _parse_line(char *, VAR *);
+static int  _check_var(pam_handle_t *, VAR *);           /* This is the real meat */
+static void _clean_var(VAR *);        
+static int  _expand_arg(pam_handle_t *, char **);
+static const char * _pam_get_item_byname(pam_handle_t *, const char *);
+static int  _define_var(pam_handle_t *, VAR *);
+static int  _undefine_var(pam_handle_t *, VAR *);
+
+/* This is a flag used to designate an empty string */
+static char quote='Z';         
+
+/* some syslogging */
+
+static void _log_err(int err, const char *format, ...)
+{
+    va_list args;
+
+    va_start(args, format);
+    openlog("PAM-env", LOG_CONS|LOG_PID, LOG_AUTH);
+    vsyslog(err, format, args);
+    va_end(args);
+    closelog();
+}
+
+/* argument parsing */
+
+#define PAM_DEBUG_ARG       0x01
+#define PAM_NEW_CONF_FILE   0x02
+#define PAM_ENV_SILENT      0x04
+#define PAM_NEW_ENV_FILE    0x10
+
+static int _pam_parse(int flags, int argc, const char **argv, char **conffile,
+	char **envfile, int *readenv)
+{
+    int ctrl=0;
+
+
+    /* step through arguments */
+    for (; argc-- > 0; ++argv) {
+
+	/* generic options */
+
+	if (!strcmp(*argv,"debug"))
+	    ctrl |= PAM_DEBUG_ARG;
+	else if (!strncmp(*argv,"conffile=",9)) {
+	    *conffile = x_strdup(9+*argv);
+	    if (*conffile != NULL) {
+		D(("new Configuration File: %s", *conffile));
+		ctrl |= PAM_NEW_CONF_FILE;
+	    } else {
+		_log_err(LOG_CRIT,
+			 "Configuration file specification missing argument - ignored");
+	    }
+	} else if (!strncmp(*argv,"envfile=",8)) {
+	    *envfile = x_strdup(8+*argv);
+	    if (*envfile != NULL) {
+		D(("new Env File: %s", *envfile));
+		ctrl |= PAM_NEW_ENV_FILE;
+	    } else {
+		_log_err(LOG_CRIT,
+			 "Env file specification missing argument - ignored");
+	    }
+	} else if (!strncmp(*argv,"readenv=",8))
+	    *readenv = atoi(8+*argv);
+	else
+	    _log_err(LOG_ERR,"pam_parse: unknown option; %s",*argv);
+    }
+
+    return ctrl;
+}
+
+static int _parse_config_file(pam_handle_t *pamh, int ctrl, char **conffile)
+{
+    int retval;
+    const char *file;
+    char buffer[BUF_SIZE];
+    FILE *conf;
+    VAR Var, *var=&Var;   
+
+    var->name=NULL; var->defval=NULL; var->override=NULL;
+    D(("Called."));
+
+    if (ctrl & PAM_NEW_CONF_FILE) {
+	file = *conffile;
+    } else {
+	file = DEFAULT_CONF_FILE;
+    }
+
+    D(("Config file name is: %s", file));
+
+    /* 
+     * Lets try to open the config file, parse it and process 
+     * any variables found.
+     */
+
+    if ((conf = fopen(file,"r")) == NULL) {
+      _log_err(LOG_ERR, "Unable to open config file: %s", 
+	       strerror(errno));
+      return PAM_IGNORE;
+    }
+
+    /* _pam_assemble_line will provide a complete line from the config file, with all 
+     * comments removed and any escaped newlines fixed up
+     */
+
+    while (( retval = _assemble_line(conf, buffer, BUF_SIZE)) > 0) {
+      D(("Read line: %s", buffer));
+
+      if ((retval = _parse_line(buffer, var)) == GOOD_LINE) {
+	retval = _check_var(pamh, var);
+
+	if (DEFINE_VAR == retval) {
+	  retval = _define_var(pamh, var);     
+
+	} else if (UNDEFINE_VAR == retval) {
+	  retval = _undefine_var(pamh, var);   
+	} 
+      } 
+      if (PAM_SUCCESS != retval && ILLEGAL_VAR != retval 
+	  && BAD_LINE != retval && PAM_BAD_ITEM != retval) break;
+      
+      _clean_var(var);    
+
+    }  /* while */
+    
+    (void) fclose(conf);
+
+    /* tidy up */
+    _clean_var(var);        /* We could have got here prematurely, this is safe though */
+    _pam_overwrite(*conffile);
+    _pam_drop(*conffile);
+    file = NULL;
+    D(("Exit."));
+    return (retval<0?PAM_ABORT:PAM_SUCCESS);
+}
+
+static int _parse_env_file(pam_handle_t *pamh, int ctrl, char **env_file)
+{
+    int retval=PAM_SUCCESS, i, t;
+    const char *file;
+    char buffer[BUF_SIZE], *key, *mark;
+    FILE *conf;
+
+    if (ctrl & PAM_NEW_ENV_FILE)
+	file = *env_file;
+    else
+	file = DEFAULT_ETC_ENVFILE;
+
+    D(("Env file name is: %s", file));
+
+    if ((conf = fopen(file,"r")) == NULL) {
+      D(("Unable to open env file: %s", strerror(errno)));
+      return PAM_ABORT;
+    }
+
+    while (_assemble_line(conf, buffer, BUF_SIZE) > 0) {
+	D(("Read line: %s", buffer));
+	key = buffer;
+
+	/* skip leading white space */
+	key += strspn(key, " \n\t");
+
+	/* skip blanks lines and comments */
+	if (!key || key[0] == '#')
+	    continue;
+
+	/* skip over "export " if present so we can be compat with
+	   bash type declerations */
+	if (strncmp(key, "export ", (size_t) 7) == 0)
+	    key += 7;
+
+	/* now find the end of value */
+	mark = key;
+	while(mark[0] != '\n' && mark[0] != '#' && mark[0] != '\0')
+	    mark++;
+	if (mark[0] != '\0')
+	    mark[0] = '\0';
+
+       /*
+	* sanity check, the key must be alpha-numeric
+	*/
+
+	for ( i = 0 ; key[i] != '=' && key[i] != '\0' ; i++ )
+	    if (!isalnum(key[i]) && key[i] != '_') {
+		D(("key is not alpha numeric - '%s', ignoring", key));
+		continue;
+	    }
+
+	/* now we try to be smart about quotes around the value,
+	   but not too smart, we can't get all fancy with escaped
+	   values like bash */
+	if (key[i] == '=' && (key[++i] == '\"' || key[i] == '\'')) {
+	    for ( t = i+1 ; key[t] != '\0' ; t++)
+		if (key[t] != '\"' && key[t] != '\'')
+		    key[i++] = key[t];
+		else if (key[t+1] != '\0')
+		    key[i++] = key[t];
+	    key[i] = '\0';
+	}
+
+	/* set the env var, if it fails, we break out of the loop */
+	retval = pam_putenv(pamh, key);
+	if (retval != PAM_SUCCESS) {
+	    D(("error setting env \"%s\"", key));
+	    break;
+	}
+    }
+    
+    (void) fclose(conf);
+
+    /* tidy up */
+    _pam_overwrite(*env_file);
+    _pam_drop(*env_file);
+    file = NULL;
+    D(("Exit."));
+    return (retval<0?PAM_IGNORE:PAM_SUCCESS);
+}
+
+/*
+ * This is where we read a line of the PAM config file. The line may be
+ * preceeded by lines of comments and also extended with "\\\n"
+ */
+
+static int _assemble_line(FILE *f, char *buffer, int buf_len)
+{
+    char *p = buffer;
+    char *s, *os;
+    int used = 0;
+
+    /* loop broken with a 'break' when a non-'\\n' ended line is read */
+
+    D(("called."));
+    for (;;) {
+	if (used >= buf_len) {
+	    /* Overflow */
+	    D(("_assemble_line: overflow"));
+	    return -1;
+	}
+	if (fgets(p, buf_len - used, f) == NULL) {
+	    if (used) {
+		/* Incomplete read */
+		return -1;
+	    } else {
+		/* EOF */
+		return 0;
+	    }
+	}
+
+	/* skip leading spaces --- line may be blank */
+
+	s = p + strspn(p, " \n\t");
+	if (*s && (*s != '#')) {
+	    os = s;
+
+	    /*
+	     * we are only interested in characters before the first '#'
+	     * character
+	     */
+
+	    while (*s && *s != '#')
+		 ++s;
+	    if (*s == '#') {
+		 *s = '\0';
+		 used += strlen(os);
+		 break;                /* the line has been read */
+	    }
+
+	    s = os;
+
+	    /*
+	     * Check for backslash by scanning back from the end of
+	     * the entered line, the '\n' has been included since
+	     * normally a line is terminated with this
+	     * character. fgets() should only return one though!
+	     */
+
+	    s += strlen(s);
+	    while (s > os && ((*--s == ' ') || (*s == '\t')
+			      || (*s == '\n')));
+
+	    /* check if it ends with a backslash */
+	    if (*s == '\\') {
+		*s = '\0';              /* truncate the line here */
+		used += strlen(os);
+		p = s;                  /* there is more ... */
+	    } else {
+		/* End of the line! */
+		used += strlen(os);
+		break;                  /* this is the complete line */
+	    }
+
+	} else {
+	    /* Nothing in this line */
+	    /* Don't move p         */
+	}
+    }
+
+    return used;
+}
+
+static int _parse_line(char *buffer, VAR *var)
+{
+  /* 
+   * parse buffer into var, legal syntax is 
+   * VARIABLE [DEFAULT=[[string]] [OVERRIDE=[value]]
+   *
+   * Any other options defined make this a bad line, 
+   * error logged and no var set
+   */
+  
+  int length, quoteflg=0;
+  char *ptr, **valptr, *tmpptr; 
+  
+  D(("Called buffer = <%s>", buffer));
+
+  length = strcspn(buffer," \t\n");
+  
+  if ((var->name = malloc(length + 1)) == NULL) {
+    _log_err(LOG_ERR, "Couldn't malloc %d bytes", length+1);
+    return PAM_BUF_ERR;
+  }
+  
+  /* 
+   * The first thing on the line HAS to be the variable name, 
+   * it may be the only thing though.
+   */
+  strncpy(var->name, buffer, length);
+  var->name[length] = '\0';
+  D(("var->name = <%s>, length = %d", var->name, length));
+
+  /* 
+   * Now we check for arguments, we only support two kinds and ('cause I am lazy)
+   * each one can actually be listed any number of times
+   */
+  
+  ptr = buffer+length;
+  while ((length = strspn(ptr, " \t")) > 0) { 
+    ptr += length;                              /* remove leading whitespace */
+    D((ptr));
+    if (strncmp(ptr,"DEFAULT=",8) == 0) {
+      ptr+=8;
+      D(("Default arg found: <%s>", ptr));
+      valptr=&(var->defval);
+    } else if (strncmp(ptr, "OVERRIDE=", 9) == 0) {
+      ptr+=9;
+      D(("Override arg found: <%s>", ptr));
+      valptr=&(var->override);
+    } else {
+      D(("Unrecognized options: <%s> - ignoring line", ptr));
+      _log_err(LOG_ERR, "Unrecognized Option: %s - ignoring line", ptr);
+      return BAD_LINE;
+    }
+    
+    if ('"' != *ptr) {       /* Escaped quotes not supported */
+      length = strcspn(ptr, " \t\n");
+      tmpptr = ptr+length;
+    } else {
+      tmpptr = strchr(++ptr, '"');   
+      if (!tmpptr) {
+	D(("Unterminated quoted string: %s", ptr-1));
+	_log_err(LOG_ERR, "Unterminated quoted string: %s", ptr-1);
+	return BAD_LINE;
+      }
+      length = tmpptr - ptr;        
+      if (*++tmpptr && ' ' != *tmpptr && '\t' != *tmpptr && '\n' != *tmpptr) {
+	D(("Quotes must cover the entire string: <%s>", ptr));
+	_log_err(LOG_ERR, "Quotes must cover the entire string: <%s>", ptr);
+	return BAD_LINE;
+      }
+      quoteflg++;
+    }
+    if (length) {
+      if ((*valptr = malloc(length + 1)) == NULL) {
+	D(("Couldn't malloc %d bytes", length+1));
+	_log_err(LOG_ERR, "Couldn't malloc %d bytes", length+1);
+	return PAM_BUF_ERR;
+      }
+      (void)strncpy(*valptr,ptr,length);
+      (*valptr)[length]='\0';
+    } else if (quoteflg--) {
+      *valptr = &quote;      /* a quick hack to handle the empty string */
+    }
+    ptr = tmpptr;         /* Start the search where we stopped */
+  } /* while */
+  
+  /* 
+   * The line is parsed, all is well.
+   */
+  
+  D(("Exit."));
+  ptr = NULL; tmpptr = NULL; valptr = NULL;
+  return GOOD_LINE;
+}
+
+static int _check_var(pam_handle_t *pamh, VAR *var)
+{
+  /* 
+   * Examine the variable and determine what action to take. 
+   * Returns DEFINE_VAR, UNDEFINE_VAR depending on action to take
+   * or a PAM_* error code if passed back from other routines
+   *
+   * if no DEFAULT provided, the empty string is assumed
+   * if no OVERRIDE provided, the empty string is assumed
+   * if DEFAULT=  and OVERRIDE evaluates to the empty string, 
+   *    this variable should be undefined
+   * if DEFAULT=""  and OVERRIDE evaluates to the empty string, 
+   *    this variable should be defined with no value
+   * if OVERRIDE=value   and value turns into the empty string, DEFAULT is used
+   *
+   * If DEFINE_VAR is to be returned, the correct value to define will
+   * be pointed to by var->value
+   */
+
+  int retval;
+
+  D(("Called."));
+
+  /*
+   * First thing to do is to expand any arguments, but only
+   * if they are not the special quote values (cause expand_arg
+   * changes memory).
+   */
+
+  if (var->defval && (&quote != var->defval) &&
+      ((retval = _expand_arg(pamh, &(var->defval))) != PAM_SUCCESS)) {
+      return retval;
+  }
+  if (var->override && (&quote != var->override) &&
+      ((retval = _expand_arg(pamh, &(var->override))) != PAM_SUCCESS)) {
+    return retval;
+  }
+
+  /* Now its easy */
+  
+  if (var->override && *(var->override) && &quote != var->override) { 
+    /* if there is a non-empty string in var->override, we use it */
+    D(("OVERRIDE variable <%s> being used: <%s>", var->name, var->override));
+    var->value = var->override;
+    retval = DEFINE_VAR;
+  } else {
+    
+    var->value = var->defval;
+    if (&quote == var->defval) {
+      /* 
+       * This means that the empty string was given for defval value 
+       * which indicates that a variable should be defined with no value
+       */
+      *var->defval = '\0';
+      D(("An empty variable: <%s>", var->name));
+      retval = DEFINE_VAR;
+    } else if (var->defval) {
+      D(("DEFAULT variable <%s> being used: <%s>", var->name, var->defval));
+      retval = DEFINE_VAR;
+    } else {
+      D(("UNDEFINE variable <%s>", var->name));
+      retval = UNDEFINE_VAR;
+    }
+  }
+
+  D(("Exit."));
+  return retval;
+}
+
+static int _expand_arg(pam_handle_t *pamh, char **value)
+{
+  const char *orig=*value, *tmpptr=NULL;
+  char *ptr;       /* 
+		    * Sure would be nice to use tmpptr but it needs to be 
+		    * a constant so that the compiler will shut up when I
+		    * call pam_getenv and _pam_get_item_byname -- sigh
+		    */
+		      
+  char type, tmpval[BUF_SIZE]; /* No unexpanded variable can be bigger than BUF_SIZE */
+  char tmp[MAX_ENV];   /* I know this shouldn't be hard-coded but it's so 
+			* much easier this way */
+
+  D(("Remember to initialize tmp!"));
+  tmp[0] = '\0';
+
+  /* 
+   * (possibly non-existent) environment variables can be used as values
+   * by prepending a "$" and wrapping in {} (ie: ${HOST}), can escape with "\"
+   * (possibly non-existent) PAM items can be used as values 
+   * by prepending a "@" and wrapping in {} (ie: @{PAM_RHOST}, can escape 
+   *
+   */
+  D(("Expanding <%s>",orig));
+  while (*orig) {     /* while there is some input to deal with */
+    if ('\\' == *orig) {
+      ++orig;
+      if ('$' != *orig && '@' != *orig) {
+	D(("Unrecognized escaped character: <%c> - ignoring", *orig));
+	_log_err(LOG_ERR, "Unrecognized escaped character: <%c> - ignoring", 
+		 *orig);
+      } else if ((strlen(tmp) + 1) < MAX_ENV) {
+	tmp[strlen(tmp)] = *orig++;        /* Note the increment */
+      } else {
+	/* is it really a good idea to try to log this? */
+	D(("Variable buffer overflow: <%s> + <%s>", tmp, tmpptr));
+	_log_err(LOG_ERR, "Variable buffer overflow: <%s> + <%s>", tmp, tmpptr);
+      }
+      continue;
+    } 
+    if ('$' == *orig || '@' == *orig) {
+      if ('{' != *(orig+1)) {
+	D(("Expandable variables must be wrapped in {} <%s> - ignoring", orig));
+	_log_err(LOG_ERR, "Expandable variables must be wrapped in {} <%s> - ignoring", 
+		 orig);
+	if ((strlen(tmp) + 1) < MAX_ENV) {
+	  tmp[strlen(tmp)] = *orig++;        /* Note the increment */
+	}
+	continue;
+      } else {
+	D(("Expandable argument: <%s>", orig));
+	type = *orig;
+	orig+=2;     /* skip the ${ or @{ characters */
+	ptr = strchr(orig, '}');
+	if (ptr) { 
+	  *ptr++ = '\0';
+	} else {
+	  D(("Unterminated expandable variable: <%s>", orig-2));
+	  _log_err(LOG_ERR, "Unterminated expandable variable: <%s>", orig-2);
+	  return PAM_ABORT;
+	}
+	strncpy(tmpval, orig, (size_t) BUF_SIZE);
+	orig=ptr;
+	/* 
+	 * so, we know we need to expand tmpval, it is either 
+	 * an environment variable or a PAM_ITEM. type will tell us which
+	 */
+	switch (type) {
+	  
+	case '$':
+	  D(("Expanding env var: <%s>",tmpval));
+	  tmpptr = pam_getenv(pamh, tmpval);
+	  D(("Expanded to <%s>", tmpptr));
+	  break;
+	  
+	case '@':
+	  D(("Expanding pam item: <%s>",tmpval));
+	  tmpptr = _pam_get_item_byname(pamh, tmpval);
+	  D(("Expanded to <%s>", tmpptr));
+	  break;
+
+	default:
+	  D(("Impossible error, type == <%c>", type));
+	  _log_err(LOG_CRIT, "Impossible error, type == <%c>", type);
+	  return PAM_ABORT;
+	}         /* switch */
+	
+	if (tmpptr) {
+	  if ((strlen(tmp) + strlen(tmpptr)) < MAX_ENV) {
+	    strcat(tmp, tmpptr);
+	  } else {
+	    /* is it really a good idea to try to log this? */
+	    D(("Variable buffer overflow: <%s> + <%s>", tmp, tmpptr));
+	    _log_err(LOG_ERR, "Variable buffer overflow: <%s> + <%s>", tmp, tmpptr);
+	  }
+	}
+      }           /* if ('{' != *orig++) */
+    } else {      /* if ( '$' == *orig || '@' == *orig) */
+      if ((strlen(tmp) + 1) < MAX_ENV) {
+	tmp[strlen(tmp)] = *orig++;        /* Note the increment */
+      } else {
+	/* is it really a good idea to try to log this? */
+	D(("Variable buffer overflow: <%s> + <%s>", tmp, tmpptr));
+	_log_err(LOG_ERR, "Variable buffer overflow: <%s> + <%s>", tmp, tmpptr);
+      }
+    }
+  }              /* for (;*orig;) */
+
+  if (strlen(tmp) > strlen(*value)) {
+    free(*value);
+    if ((*value = malloc(strlen(tmp) +1)) == NULL) {
+      D(("Couldn't malloc %d bytes for expanded var", strlen(tmp)+1));
+      _log_err(LOG_ERR,"Couldn't malloc %d bytes for expanded var",
+	       strlen(tmp)+1);
+      return PAM_BUF_ERR;
+    }
+  }
+  strcpy(*value, tmp);
+  memset(tmp,'\0',sizeof(tmp));
+  D(("Exit."));
+
+  return PAM_SUCCESS;
+}
+
+static const char * _pam_get_item_byname(pam_handle_t *pamh, const char *name)
+{
+  /* 
+   * This function just allows me to use names as given in the config
+   * file and translate them into the appropriate PAM_ITEM macro
+   */
+
+  int item;
+  const char *itemval;
+
+  D(("Called."));
+  if (strcmp(name, "PAM_USER") == 0) {
+    item = PAM_USER;
+  } else if (strcmp(name, "PAM_USER_PROMPT") == 0) {
+    item = PAM_USER_PROMPT;
+  } else if (strcmp(name, "PAM_TTY") == 0) {
+    item = PAM_TTY;
+  } else if (strcmp(name, "PAM_RUSER") == 0) {
+    item = PAM_RUSER;
+  } else if (strcmp(name, "PAM_RHOST") == 0) {
+    item = PAM_RHOST;
+  } else {
+    D(("Unknown PAM_ITEM: <%s>", name));
+    _log_err(LOG_ERR, "Unknown PAM_ITEM: <%s>", name);
+    return NULL;
+  }
+  
+  if (pam_get_item(pamh, item, (const void **)&itemval) != PAM_SUCCESS) {
+    D(("pam_get_item failed"));
+    return NULL;     /* let pam_get_item() log the error */
+  }
+  D(("Exit."));
+  return itemval;
+}
+
+static int _define_var(pam_handle_t *pamh, VAR *var)
+{
+  /* We have a variable to define, this is a simple function */
+  
+  char *envvar;
+  int size, retval=PAM_SUCCESS;
+  
+  D(("Called."));
+  size = strlen(var->name)+strlen(var->value)+2;
+  if ((envvar = malloc(size)) == NULL) {
+    D(("Malloc fail, size = %d", size));
+    _log_err(LOG_ERR, "Malloc fail, size = %d", size);
+    return PAM_BUF_ERR;
+  }
+  (void) sprintf(envvar,"%s=%s",var->name,var->value);
+  retval = pam_putenv(pamh, envvar);
+  free(envvar); envvar=NULL;
+  D(("Exit."));
+  return retval;
+}
+
+static int _undefine_var(pam_handle_t *pamh, VAR *var)
+{
+  /* We have a variable to undefine, this is a simple function */
+  
+  D(("Called and exit."));
+  return pam_putenv(pamh, var->name);
+}
+
+static void   _clean_var(VAR *var)
+{
+    if (var->name) {
+      free(var->name); 
+    }
+    if (var->defval && (&quote != var->defval)) {
+      free(var->defval); 
+    }
+    if (var->override && (&quote != var->override)) {
+      free(var->override); 
+    }
+    var->name = NULL;
+    var->value = NULL;    /* never has memory specific to it */
+    var->defval = NULL;
+    var->override = NULL;
+    return;
+}
+
+
+
+/* --- authentication management functions (only) --- */
+
+PAM_EXTERN
+int pam_sm_authenticate(pam_handle_t *pamh, int flags, int argc,
+			const char **argv)
+{ 
+  return PAM_IGNORE;
+}
+
+PAM_EXTERN 
+int pam_sm_setcred(pam_handle_t *pamh, int flags, int argc, 
+		   const char **argv)
+{
+  int retval, ctrl, readenv=DEFAULT_READ_ENVFILE;
+  char *conf_file=NULL, *env_file=NULL;
+
+  /*
+   * this module sets environment variables read in from a file
+   */
+  
+  D(("Called."));
+  ctrl = _pam_parse(flags, argc, argv, &conf_file, &env_file, &readenv);
+
+  retval = _parse_config_file(pamh, ctrl, &conf_file);
+
+  if(readenv)
+    _parse_env_file(pamh, ctrl, &env_file);
+
+  /* indicate success or failure */
+  
+  D(("Exit."));
+  return retval;
+}
+
+PAM_EXTERN 
+int pam_sm_acct_mgmt(pam_handle_t *pamh, int flags, int argc, 
+		     const char **argv)
+{
+  _log_err(LOG_NOTICE, "pam_sm_acct_mgmt called inappropriatly");
+  return PAM_SERVICE_ERR;
+}
+ 
+PAM_EXTERN
+int pam_sm_open_session(pam_handle_t *pamh,int flags,int argc
+			,const char **argv)
+{
+  int retval, ctrl, readenv=DEFAULT_READ_ENVFILE;
+  char *conf_file=NULL, *env_file=NULL;
+  
+  /*
+   * this module sets environment variables read in from a file
+   */
+  
+  D(("Called."));
+  ctrl = _pam_parse(flags, argc, argv, &conf_file, &env_file, &readenv);
+  
+  retval = _parse_config_file(pamh, ctrl, &conf_file);
+  
+  if(readenv)
+    _parse_env_file(pamh, ctrl, &env_file);
+
+  /* indicate success or failure */
+  
+  D(("Exit."));
+  return retval;
+}
+
+PAM_EXTERN
+int pam_sm_close_session(pam_handle_t *pamh,int flags,int argc,
+			 const char **argv)
+{
+  D(("Called and Exit"));
+  return PAM_SUCCESS;
+}
+
+PAM_EXTERN 
+int pam_sm_chauthtok(pam_handle_t *pamh, int flags, int argc, 
+		     const char **argv)
+{
+  _log_err(LOG_NOTICE, "pam_sm_chauthtok called inappropriatly");
+  return PAM_SERVICE_ERR;
+}
+
+#ifdef PAM_STATIC
+
+/* static module data */
+
+struct pam_module _pam_env_modstruct = {
+     "pam_env",
+     pam_sm_authenticate,
+     pam_sm_setcred,
+     pam_sm_acct_mgmt,
+     pam_sm_open_session,
+     pam_sm_close_session,
+     pam_sm_chauthtok,
+};
+
+#endif
+
+/* end of module definition */
diff --git a/modules/pam_env/pam_env.conf-example b/modules/pam_env/pam_env.conf-example
new file mode 100644
index 00000000..c2c4333f
--- /dev/null
+++ b/modules/pam_env/pam_env.conf-example
@@ -0,0 +1,72 @@
+# $Date$
+# $Author$
+# $Id$
+#
+# This is the configuration file for pam_env, a PAM module to load in 
+# a configurable list of environment variables for a 
+# 
+# The original idea for this came from Andrew G. Morgan ...
+#<quote>
+#   Mmm. Perhaps you might like to write a pam_env module that reads a
+#   default environment from a file? I can see that as REALLY
+#   useful... Note it would be an "auth" module that returns PAM_IGNORE
+#   for the auth part and sets the environment returning PAM_SUCCESS in
+#   the setcred function...
+#</quote>
+#
+# What I wanted was the REMOTEHOST variable set, purely for selfish
+# reasons, and AGM didn't want it added to the SimpleApps login
+# program (which is where I added the patch). So, my first concern is
+# that variable, from there there are numerous others that might/would
+# be useful to be set: NNTPSERVER, LESS, PATH, PAGER, MANPAGER .....
+#
+# Of course, these are a different kind of variable than REMOTEHOST in
+# that they are things that are likely to be configured by
+# administrators rather than set by logging in, how to treat them both
+# in the same config file?
+#
+# Here is my idea: 
+#
+# Each line starts with the variable name, there are then two possible
+# options for each variable DEFAULT and OVERRIDE. 
+# DEFAULT allows and administrator to set the value of the
+# variable  to some default value, if none is supplied then the empty
+# string is assumed. The OVERRIDE option tells pam_env that it should
+# enter in its value (overriding the default value) if there is one
+# to use. OVERRIDE is not used, "" is assumed and no override will be
+# done. 
+#
+# VARIABLE   [DEFAULT=[value]]  [OVERRIDE=[value]]
+#
+# (Possibly non-existent) environment variables may be used in values
+# using the ${string} syntax and (possibly non-existent) PAM_ITEMs may
+# be used in values using the @{string} syntax. Both the $ and @
+# characters can be backslash escaped to be used as literal values
+# values can be delimited with "", escaped " not supported.
+#
+#
+# First, some special variables
+#
+# Set the REMOTEHOST variable for any hosts that are remote, default
+# to "localhost" rather than not being set at all
+#REMOTEHOST	DEFAULT=localhost OVERRIDE=@{PAM_RHOST}
+#
+# Set the DISPLAY variable if it seems reasonable 
+#DISPLAY		DEFAULT=${REMOTEHOST}:0.0 OVERRIDE=${DISPLAY}
+#
+#
+#  Now some simple variables
+#
+#PAGER		DEFAULT=less
+#MANPAGER	DEFAULT=less
+#LESS		DEFAULT="M q e h15 z23 b80"
+#NNTPSERVER	DEFAULT=localhost
+#PATH		DEFAULT=${HOME}/bin:/usr/local/bin:/bin\
+#:/usr/bin:/usr/local/bin/X11:/usr/bin/X11
+#
+# silly examples of escaped variables, just to show how they work.
+#
+#DOLLAR		DEFAULT=\$
+#DOLLARDOLLAR	DEFAULT=	OVERRIDE=\$${DOLLAR}
+#DOLLARPLUS	DEFAULT=\${REMOTEHOST}${REMOTEHOST}
+#ATSIGN		DEFAULT=""	OVERRIDE=\@