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-rw-r--r--pam_pwdfile.c392
1 files changed, 108 insertions, 284 deletions
diff --git a/pam_pwdfile.c b/pam_pwdfile.c
index ec2bd96..9b96fe3 100644
--- a/pam_pwdfile.c
+++ b/pam_pwdfile.c
@@ -1,13 +1,9 @@
/* pam_pwdfile.c copyright 1999-2003 by Charl P. Botha <cpbotha@ieee.org>
*
- * $Id: pam_pwdfile.c,v 1.18 2003/12/20 19:21:19 cpbotha Exp $
- *
* pam authentication module that can be pointed at any username/crypted
* text file so that pam using application can use an alternate set of
* passwords than specified in system password database
*
- * version 0.99
- *
* Copyright (c) Charl P. Botha, 1999-2003. All rights reserved
*
* Redistribution and use in source and binary forms, with or without
@@ -42,9 +38,20 @@
* OF THE POSSIBILITY OF SUCH DAMAGE.
*/
+#ifdef USE_CRYPT_R
+#define _GNU_SOURCE
+#include <crypt.h>
+#else
+#ifndef _XOPEN_SOURCE
+#define _XOPEN_SOURCE 700
+#endif
+#ifndef _BSD_SOURCE
+#define _BSD_SOURCE
+#endif
+#endif
+
#include <features.h>
#include <syslog.h>
-#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
@@ -54,44 +61,16 @@
#include <sys/wait.h>
#include <sys/file.h>
#include <unistd.h>
+#include <syslog.h>
#include <security/pam_appl.h>
#define PAM_SM_AUTH
#include <security/pam_modules.h>
+#include <security/pam_ext.h>
#include "md5.h"
-extern char *crypt(const char *key, const char *salt);
-extern char *bigcrypt(const char *key, const char *salt);
-
-#define PWDF_PARAM "pwdfile"
-#define FLOCK_PARAM "flock"
-#define NODELAY_PARAM "nodelay"
-#define PWDFN_LEN 256
-#define CRYPTED_DESPWD_LEN 13
-#define CRYPTED_MD5PWD_LEN 34
-#define CRYPTED_BCPWD_LEN 178
-
-#ifdef DEBUG
-# define D(a) a;
-#else
-# define D(a) {}
-#endif
-
-/* prototypes */
-int converse(pam_handle_t *, int, struct pam_message **, struct pam_response **);
-int _set_auth_tok(pam_handle_t *, int, int, const char **);
-
-/* logging function ripped from pam_listfile.c */
-static void _pam_log(int err, const char *format, ...) {
- va_list args;
-
- va_start(args, format);
- openlog("pam_pwdfile", LOG_CONS|LOG_PID, LOG_AUTH);
- vsyslog(err, format, args);
- va_end(args);
- closelog();
-}
+#include "bigcrypt.h"
static int lock_fd(int fd) {
int delay;
@@ -110,304 +89,148 @@ static int lock_fd(int fd) {
return -1;
}
-/* this function ripped from pam_unix/support.c */
-int converse( pam_handle_t *pamh,
- int nargs,
- struct pam_message **message,
- struct pam_response **response ) {
- int retval;
- struct pam_conv *conv;
-
- retval = pam_get_item( pamh, PAM_CONV, (const void **) &conv ) ;
- if ( retval == PAM_SUCCESS ) {
- retval = conv->conv( nargs,
- ( const struct pam_message ** ) message,
- response,
- conv->appdata_ptr );
- }
- return retval;
-}
-
-/* this function ripped from pam_unix/support.c */
-int _set_auth_tok( pam_handle_t *pamh,
- int flags, int argc,
- const char **argv ) {
- int retval;
- char *p;
-
- struct pam_message msg[1],*pmsg[1];
- struct pam_response *resp;
-
- /* set up conversation call */
-
- pmsg[0] = &msg[0];
- msg[0].msg_style = PAM_PROMPT_ECHO_OFF;
- msg[0].msg = "Password: ";
- resp = NULL;
-
- if ( ( retval = converse( pamh, 1 , pmsg, &resp ) ) != PAM_SUCCESS )
- return retval;
-
- if ( resp )
- {
- if ( ( flags & PAM_DISALLOW_NULL_AUTHTOK ) &&
- resp[0].resp == NULL )
- {
- free( resp );
- return PAM_AUTH_ERR;
- }
-
- p = resp[ 0 ].resp;
-
- /* This could be a memory leak. If resp[0].resp
- is malloc()ed, then it has to be free()ed!
- -- alex
- */
-
- resp[ 0 ].resp = NULL;
-
- }
- else
- return PAM_CONV_ERR;
-
- free( resp );
- pam_set_item( pamh, PAM_AUTHTOK, p );
- return PAM_SUCCESS;
-}
-
-
-/* puts the crypted password corresponding to user "name" in password,
- * from a file with lines consisting of: name:crypted_password
- * if unsucessful, returns 0
- */
-static int fgetpwnam(FILE *stream, const char *name, char *password) {
- char tempLine[256], *tpointer, *curname, *curpass, *fgr;
- int loopdone, pwdfound;
- int len;
-
- /* go to beginning of file */
- rewind(stream);
- /* some control variables */
- loopdone = pwdfound = 0;
- /* fgets should do this, but we make sure */
- tempLine[255] = '\0';
- /* iterate through lines in file, until end of file */
- do {
- /* get the current line */
- fgr = fgets(tempLine,255,stream);
- /* if it's valid, go on */
- if ( fgr != NULL) {
- /* first get the username out */
- tpointer = tempLine;
- curname = strsep(&tpointer,":");
- /* check to see if it's the right one */
- if (strcmp(curname,name)==0) {
- /* at least we know our loop is done */
- loopdone = 1;
- /* remove possible trailing newline */
- len = strlen(tpointer);
- if (tpointer[len - 1] == '\n')
- tpointer[len - 1] = '\0';
- /* get the password and put it in its place */
- curpass = strsep(&tpointer,":");
- if (curpass != NULL) {
- /* we use bigcrypt pwd len, as this is just a safe maximum */
- strncpy(password,curpass,CRYPTED_BCPWD_LEN+1);
- pwdfound = 1;
- } /* if (curpass... */
- } /* if (strcmp(curname... */
- } /* if (tempLine... */
- } while (fgr != NULL);
- return pwdfound;
-}
-
/* expected hook for auth service */
+__attribute__((visibility("default")))
PAM_EXTERN int pam_sm_authenticate(pam_handle_t *pamh, int flags,
int argc, const char **argv) {
- int retval, pcnt, pwdfilename_found;
+ int i;
const char *name;
- char *password;
- char pwdfilename[PWDFN_LEN];
- char salt[12], stored_crypted_password[CRYPTED_BCPWD_LEN+1];
- char *crypted_password;
+ char const * password;
+ char const * pwdfilename = NULL;
+ char const * stored_crypted_password = NULL;
+ char const * crypted_password;
FILE *pwdfile;
int use_flock = 0;
int use_delay = 1;
- int temp_result = 0;
+ int legacy_crypt = 0;
+ int debug = 0;
+ char * linebuf = NULL;
+ size_t linebuflen;
+#ifdef USE_CRYPT_R
+ struct crypt_data crypt_buf;
+#endif
/* we require the pwdfile switch and argument to be present, else we don't work */
- /* pcnt is the parameter counter variable for iterating through argv */
- pcnt = pwdfilename_found = 0;
- do {
- /* see if the current parameter looks like "pwdfile" */
- if (strcmp(argv[pcnt],PWDF_PARAM)==0) {
- /* if argv is long enough, grab the subsequent parameter */
- if (pcnt+1 < argc) {
- /* make sure we can't overflow */
- strncpy(pwdfilename,argv[++pcnt],PWDFN_LEN);
- /* indicate that we've found it */
- pwdfilename_found = 1;
- }
- /* also check for "pwdfile=blah" */
- } else if (strncmp(argv[pcnt],PWDF_PARAM "=",sizeof(PWDF_PARAM "=")-1)==0) {
- /* make sure we can't overflow */
- strncpy(pwdfilename,argv[pcnt]+sizeof(PWDF_PARAM),PWDFN_LEN);
- /* indicate that we've found it */
- pwdfilename_found = 1;
- } else if (strcmp(argv[pcnt],FLOCK_PARAM)==0) {
- /* we have a "flock" parameter */
+ for (i = 0; i < argc; ++i) {
+ if (!strcmp(argv[i], "pwdfile") && i + 1 < argc)
+ pwdfilename = argv[++i];
+ else if (!strncmp(argv[i], "pwdfile=", strlen("pwdfile=")))
+ pwdfilename = argv[i] + strlen("pwdfile=");
+ else if (!strcmp(argv[i], "flock"))
use_flock = 1;
- } else if (strcmp(argv[pcnt],"no" FLOCK_PARAM)==0) {
- /* or a "noflock" parameter */
+ else if (!strcmp(argv[i], "noflock"))
use_flock = 0;
- } else if (strcmp(argv[pcnt],NODELAY_PARAM)==0) {
- /* no delay on authentication failure */
+ else if (!strcmp(argv[i], "nodelay"))
use_delay = 0;
- }
-
- } while (++pcnt < argc);
+ else if (!strcmp(argv[i], "debug"))
+ debug = 1;
+ else if (!strcmp(argv[i], "legacy_crypt"))
+ legacy_crypt = 1;
+ }
#ifdef HAVE_PAM_FAIL_DELAY
if (use_delay) {
- D(("setting delay"));
- (void) pam_fail_delay(pamh, 2000000); /* 2 sec delay for on failure */
+ if (debug) pam_syslog(pamh, LOG_DEBUG, "setting fail delay");
+ (void) pam_fail_delay(pamh, 2000000); /* 2 sec */
}
#endif
- /* for some or other reason, the password file wasn't specified */
- if (!pwdfilename_found) {
- _pam_log(LOG_ERR,"password file name not specified");
+ if (!pwdfilename) {
+ pam_syslog(pamh, LOG_ERR, "password file name not specified");
return PAM_AUTHINFO_UNAVAIL;
}
- /* DEBUG */
- D(_pam_log(LOG_ERR, "password filename extracted"));
-
- /* now try to open the password file */
- if ((pwdfile=fopen(pwdfilename,"r"))==NULL) {
- _pam_log(LOG_ERR,"couldn't open password file %s",pwdfilename);
- return PAM_AUTHINFO_UNAVAIL;
+ if (pam_get_user(pamh, &name, NULL) != PAM_SUCCESS) {
+ pam_syslog(pamh, LOG_ERR, "couldn't get username from PAM stack");
+ return PAM_AUTH_ERR;
}
+ if (debug) pam_syslog(pamh, LOG_DEBUG, "username is %s", name);
- /* set a lock on the password file */
- if (use_flock && lock_fd(fileno(pwdfile)) == -1) {
- _pam_log(LOG_ERR,"couldn't lock password file %s",pwdfilename);
+ if (!(pwdfile = fopen(pwdfilename, "r"))) {
+ pam_syslog(pamh, LOG_ALERT, "couldn't open password file %s", pwdfilename);
return PAM_AUTHINFO_UNAVAIL;
}
- /* get user name */
- if ((retval = pam_get_user(pamh,&name,"login: ")) != PAM_SUCCESS) {
- _pam_log(LOG_ERR, "username not found");
+ if (use_flock && lock_fd(fileno(pwdfile)) == -1) {
+ pam_syslog(pamh, LOG_ALERT, "couldn't lock password file %s", pwdfilename);
fclose(pwdfile);
- return retval;
+ return PAM_AUTHINFO_UNAVAIL;
}
-
- /* DEBUG */
- D(_pam_log(LOG_ERR,"username is %s", name));
-
- /* get password - code from pam_unix_auth.c */
- pam_get_item(pamh, PAM_AUTHTOK, (void *)&password);
- if (!password) {
- retval = _set_auth_tok(pamh, flags, argc, argv);
- if (retval!=PAM_SUCCESS) {
- fclose(pwdfile);
- return retval;
+ /* get the crypted password corresponding to this user out of pwdfile */
+ while (getline(&linebuf, &linebuflen, pwdfile) > 0) {
+ /* strsep changes its argument, make a copy */
+ char * nexttok = linebuf;
+
+ /* first field: username */
+ char * curtok = strsep(&nexttok, ":");
+
+ /* skip non-matching usernames */
+ if (strcmp(curtok, name))
+ continue;
+
+ /* second field: password (until next colon or newline) */
+ if ((curtok = strsep(&nexttok, ":\n"))) {
+ stored_crypted_password = curtok;
+ break;
}
}
- pam_get_item(pamh, PAM_AUTHTOK, (void *)&password);
+ fclose(pwdfile);
+ /* we keep linebuf (allocated by getline), stored_crypted_password is pointing into it */
+
+ if (!stored_crypted_password)
+ if (debug) pam_syslog(pamh, LOG_ERR, "user not found in password database");
- if ((retval = pam_get_item(pamh, PAM_AUTHTOK, (void *)&password)) != PAM_SUCCESS) {
- _pam_log(LOG_ERR, "auth token not found");
- fclose(pwdfile);
- return retval;
+ if (stored_crypted_password && !strlen(stored_crypted_password)) {
+ if (debug) pam_syslog(pamh, LOG_DEBUG, "user has empty password field");
+ free(linebuf);
+ return flags & PAM_DISALLOW_NULL_AUTHTOK ? PAM_AUTH_ERR : PAM_SUCCESS;
}
- /* DEBUG */
- D(_pam_log(LOG_ERR,"got password from user", password));
-
- /* now crypt password and compare to the user entry in the password file */
- /* first make sure password is long enough -- may I do this? */
- if (strlen(password)<2 || password==NULL) {
- _pam_log(LOG_ERR,"password too short or NULL");
- fclose(pwdfile);
+ if (pam_get_authtok(pamh, PAM_AUTHTOK, &password, NULL) != PAM_SUCCESS) {
+ pam_syslog(pamh, LOG_ERR, "couldn't get password from PAM stack");
+ free(linebuf);
return PAM_AUTH_ERR;
}
- /* get the crypted password corresponding to this user */
- if (!fgetpwnam(pwdfile, name, stored_crypted_password)) {
- _pam_log(LOG_ERR,"user not found in password database");
- fclose(pwdfile);
- return PAM_AUTHINFO_UNAVAIL;
+ if (!stored_crypted_password) {
+ free(linebuf);
+ return PAM_USER_UNKNOWN;
}
- /* DEBUG */
- D(_pam_log(LOG_ERR,"got crypted password == '%s'", stored_crypted_password));
-
+ if (debug) pam_syslog(pamh, LOG_DEBUG, "got crypted password == '%s'", stored_crypted_password);
- temp_result = 0;
+#ifdef USE_CRYPT_R
+ crypt_buf.initialized = 0;
+ if (!(crypted_password = crypt_r(password, stored_crypted_password, &crypt_buf))) {
+#else
+ if (!(crypted_password = crypt(password, stored_crypted_password))) {
+#endif
+ pam_syslog(pamh, LOG_ERR, "crypt() failed");
+ free(linebuf);
+ return PAM_AUTH_ERR;
+ }
- /* Extract the salt and set the passwd length, depending on MD5 or DES */
- if (strncmp(stored_crypted_password, "$1$", 3) == 0) {
- D(_pam_log(LOG_ERR,"password hash type is 'md5'"));
- /* get out the salt into "salt" */
- strncpy(salt, stored_crypted_password, 11);
- salt[11] = '\0';
- stored_crypted_password[CRYPTED_MD5PWD_LEN] = '\0';
- /* try both md5 crypts */
- crypted_password = Goodcrypt_md5(password, salt);
- if (strcmp(crypted_password, stored_crypted_password) == 0)
- {
- temp_result = 1;
- }
+ if (legacy_crypt && strcmp(crypted_password, stored_crypted_password)) {
+ if (!strncmp(stored_crypted_password, "$1$", 3))
+ crypted_password = Brokencrypt_md5(password, stored_crypted_password);
else
- {
- crypted_password = Brokencrypt_md5(password, salt);
- if (strcmp(crypted_password, stored_crypted_password) == 0)
- {
- temp_result = 1;
- }
- }
- } else {
- /* get the salt out into "salt" */
- strncpy(salt, stored_crypted_password, 2);
- salt[2] = '\0';
- stored_crypted_password[CRYPTED_BCPWD_LEN] = '\0';
-
- if (strlen(stored_crypted_password) <= CRYPTED_DESPWD_LEN) {
- D(_pam_log(LOG_ERR,"password hash type is 'crypt'"));
- crypted_password = crypt(password, salt);
- } else {
- D(_pam_log(LOG_ERR,"password hash type is 'bigcrypt'"));
- crypted_password = bigcrypt(password, salt);
- }
-
- if (strcmp(crypted_password, stored_crypted_password) == 0)
- {
- temp_result = 1;
- }
+ crypted_password = bigcrypt(password, stored_crypted_password);
}
-
- /* DEBUG */
- D(_pam_log(LOG_ERR,"user password crypted is '%s'", crypted_password));
-
- /* if things don't match up, complain */
- if (!temp_result)
- {
- _pam_log(LOG_ERR,"wrong password for user %s",name);
- fclose(pwdfile);
+
+ if (strcmp(crypted_password, stored_crypted_password)) {
+ pam_syslog(pamh, LOG_NOTICE, "wrong password for user %s", name);
+ free(linebuf);
return PAM_AUTH_ERR;
}
- /* DEBUG */
- D(_pam_log(LOG_ERR,"passwords match"));
-
- /* we've gotten here, i.e. authentication was sucessful! */
- fclose(pwdfile);
+ if (debug) pam_syslog(pamh, LOG_DEBUG, "passwords match");
+ free(linebuf);
return PAM_SUCCESS;
}
/* another expected hook */
+__attribute__((visibility("default")))
PAM_EXTERN int pam_sm_setcred(pam_handle_t *pamh, int flags,
int argc, const char **argv)
{
@@ -425,3 +248,4 @@ struct pam_module _pam_listfile_modstruct = {
NULL,
};
#endif
+/* vim:set ts=8 sw=4: */
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-17 04:11:38 +0000