diff options
Diffstat (limited to 'modules/pam_env')
| -rw-r--r-- | modules/pam_env/.cvsignore | 1 | ||||
| -rw-r--r-- | modules/pam_env/Makefile | 111 | ||||
| -rw-r--r-- | modules/pam_env/README | 72 | ||||
| -rwxr-xr-x | modules/pam_env/install_conf | 46 | ||||
| -rw-r--r-- | modules/pam_env/pam_env.c | 839 | ||||
| -rw-r--r-- | modules/pam_env/pam_env.conf-example | 72 |
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 = "e; /* 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 && ("e != var->defval) && + ((retval = _expand_arg(pamh, &(var->defval))) != PAM_SUCCESS)) { + return retval; + } + if (var->override && ("e != var->override) && + ((retval = _expand_arg(pamh, &(var->override))) != PAM_SUCCESS)) { + return retval; + } + + /* Now its easy */ + + if (var->override && *(var->override) && "e != 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 ("e == 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 && ("e != var->defval)) { + free(var->defval); + } + if (var->override && ("e != 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=\@ |