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-rw-r--r--Linux-PAM/modules/pam_access/pam_access.c497
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diff --git a/Linux-PAM/modules/pam_access/pam_access.c b/Linux-PAM/modules/pam_access/pam_access.c
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+/* pam_access module */
+
+/*
+ * Written by Alexei Nogin <alexei@nogin.dnttm.ru> 1997/06/15
+ * (I took login_access from logdaemon-5.6 and converted it to PAM
+ * using parts of pam_time code.)
+ *
+ ************************************************************************
+ * Copyright message from logdaemon-5.6 (original file name DISCLAIMER)
+ ************************************************************************
+ * Copyright 1995 by Wietse Venema. All rights reserved. Individual files
+ * may be covered by other copyrights (as noted in the file itself.)
+ *
+ * This material was originally written and compiled by Wietse Venema at
+ * Eindhoven University of Technology, The Netherlands, in 1990, 1991,
+ * 1992, 1993, 1994 and 1995.
+ *
+ * Redistribution and use in source and binary forms are permitted
+ * provided that this entire copyright notice is duplicated in all such
+ * copies.
+ *
+ * This software is provided "as is" and without any expressed or implied
+ * warranties, including, without limitation, the implied warranties of
+ * merchantibility and fitness for any particular purpose.
+ *************************************************************************
+ */
+
+#include <security/_pam_aconf.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include <stdarg.h>
+#include <syslog.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <pwd.h>
+#include <grp.h>
+#include <errno.h>
+#include <ctype.h>
+#include <sys/utsname.h>
+
+#ifndef BROKEN_NETWORK_MATCH
+# include <netdb.h>
+# include <sys/socket.h>
+#endif
+
+/*
+ * here, we make definitions for the externally accessible functions
+ * in this file (these definitions are required for static modules
+ * but strongly encouraged generally) they are used to instruct the
+ * modules include file to define their prototypes.
+ */
+
+#define PAM_SM_ACCOUNT
+
+#include <security/_pam_macros.h>
+#include <security/pam_modules.h>
+
+int strcasecmp(const char *s1, const char *s2);
+
+/* login_access.c from logdaemon-5.6 with several changes by A.Nogin: */
+
+ /*
+ * This module implements a simple but effective form of login access
+ * control based on login names and on host (or domain) names, internet
+ * addresses (or network numbers), or on terminal line names in case of
+ * non-networked logins. Diagnostics are reported through syslog(3).
+ *
+ * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
+ */
+
+#if !defined(MAXHOSTNAMELEN) || (MAXHOSTNAMELEN < 64)
+#undef MAXHOSTNAMELEN
+#define MAXHOSTNAMELEN 256
+#endif
+
+#ifdef DEFAULT_CONF_FILE
+# define PAM_ACCESS_CONFIG DEFAULT_CONF_FILE
+#else
+# define PAM_ACCESS_CONFIG "/etc/security/access.conf"
+#endif
+
+ /* Delimiters for fields and for lists of users, ttys or hosts. */
+
+static const char *fs = ":"; /* field separator */
+static const char sep[] = ", \t"; /* list-element separator */
+
+ /* Constants to be used in assignments only, not in comparisons... */
+
+#define YES 1
+#define NO 0
+
+ /*
+ * A structure to bundle up all login-related information to keep the
+ * functional interfaces as generic as possible.
+ */
+struct login_info {
+ struct passwd *user;
+ char *from;
+ const char *config_file;
+ const char *service;
+};
+
+/* --- static functions for checking whether the user should be let in --- */
+
+static void _log_err(const char *format, ... )
+{
+ va_list args;
+
+ va_start(args, format);
+ openlog("pam_access", LOG_CONS|LOG_PID, LOG_AUTH);
+ vsyslog(LOG_ERR, format, args);
+ va_end(args);
+ closelog();
+}
+
+/* Parse module config arguments */
+
+static int parse_args(struct login_info *loginfo, int argc, const char **argv)
+{
+ int i;
+
+ for (i=0; i<argc; ++i) {
+ if (!strncmp("fieldsep=", argv[i], 9)) {
+
+ /* the admin wants to override the default field separators */
+ fs = argv[i]+9;
+
+ } else if (!strncmp("accessfile=", argv[i], 11)) {
+ FILE *fp = fopen(11 + argv[i], "r");
+
+ if (fp) {
+ loginfo->config_file = 11 + argv[i];
+ fclose(fp);
+ } else {
+ _log_err("for service [%s] failed to open accessfile=[%s]"
+ , loginfo->service, 11 + argv[i]);
+ return 0;
+ }
+
+ } else {
+ _log_err("unrecognized option [%s]", argv[i]);
+ }
+ }
+
+ return 1; /* OK */
+}
+
+typedef int match_func (char *, struct login_info *);
+
+static int list_match (char *, struct login_info *,
+ match_func *);
+static int user_match (char *, struct login_info *);
+static int from_match (char *, struct login_info *);
+static int string_match (char *, char *);
+
+/* login_access - match username/group and host/tty with access control file */
+
+static int login_access(struct login_info *item)
+{
+ FILE *fp;
+ char line[BUFSIZ];
+ char *perm; /* becomes permission field */
+ char *users; /* becomes list of login names */
+ char *froms; /* becomes list of terminals or hosts */
+ int match = NO;
+ int end;
+ int lineno = 0; /* for diagnostics */
+
+ /*
+ * Process the table one line at a time and stop at the first match.
+ * Blank lines and lines that begin with a '#' character are ignored.
+ * Non-comment lines are broken at the ':' character. All fields are
+ * mandatory. The first field should be a "+" or "-" character. A
+ * non-existing table means no access control.
+ */
+
+ if ((fp = fopen(item->config_file, "r"))!=NULL) {
+ while (!match && fgets(line, sizeof(line), fp)) {
+ lineno++;
+ if (line[end = strlen(line) - 1] != '\n') {
+ _log_err("%s: line %d: missing newline or line too long",
+ item->config_file, lineno);
+ continue;
+ }
+ if (line[0] == '#')
+ continue; /* comment line */
+ while (end > 0 && isspace(line[end - 1]))
+ end--;
+ line[end] = 0; /* strip trailing whitespace */
+ if (line[0] == 0) /* skip blank lines */
+ continue;
+ if (!(perm = strtok(line, fs))
+ || !(users = strtok((char *) 0, fs))
+ || !(froms = strtok((char *) 0, fs))
+ || strtok((char *) 0, fs)) {
+ _log_err("%s: line %d: bad field count",
+ item->config_file, lineno);
+ continue;
+ }
+ if (perm[0] != '+' && perm[0] != '-') {
+ _log_err("%s: line %d: bad first field",
+ item->config_file, lineno);
+ continue;
+ }
+ match = (list_match(froms, item, from_match)
+ && list_match(users, item, user_match));
+ }
+ (void) fclose(fp);
+ } else if (errno != ENOENT) {
+ _log_err("cannot open %s: %m", item->config_file);
+ }
+ return (match == 0 || (line[0] == '+'));
+}
+
+/* list_match - match an item against a list of tokens with exceptions */
+
+static int list_match(char *list, struct login_info *item, match_func *match_fn)
+{
+ char *tok;
+ int match = NO;
+
+ /*
+ * Process tokens one at a time. We have exhausted all possible matches
+ * when we reach an "EXCEPT" token or the end of the list. If we do find
+ * a match, look for an "EXCEPT" list and recurse to determine whether
+ * the match is affected by any exceptions.
+ */
+
+ for (tok = strtok(list, sep); tok != 0; tok = strtok((char *) 0, sep)) {
+ if (strcasecmp(tok, "EXCEPT") == 0) /* EXCEPT: give up */
+ break;
+ if ((match = (*match_fn) (tok, item))) /* YES */
+ break;
+ }
+ /* Process exceptions to matches. */
+
+ if (match != NO) {
+ while ((tok = strtok((char *) 0, sep)) && strcasecmp(tok, "EXCEPT"))
+ /* VOID */ ;
+ if (tok == 0 || list_match((char *) 0, item, match_fn) == NO)
+ return (match);
+ }
+ return (NO);
+}
+
+/* myhostname - figure out local machine name */
+
+static char * myhostname(void)
+{
+ static char name[MAXHOSTNAMELEN + 1];
+
+ gethostname(name, MAXHOSTNAMELEN);
+ name[MAXHOSTNAMELEN] = 0;
+ return (name);
+}
+
+/* netgroup_match - match group against machine or user */
+
+static int netgroup_match(char *group, char *machine, char *user)
+{
+#ifdef NIS
+ static char *mydomain = 0;
+
+ if (mydomain == 0)
+ yp_get_default_domain(&mydomain);
+ return (innetgr(group, machine, user, mydomain));
+#else
+ _log_err("NIS netgroup support not configured");
+ return (NO);
+#endif
+}
+
+/* user_match - match a username against one token */
+
+static int user_match(char *tok, struct login_info *item)
+{
+ char *string = item->user->pw_name;
+ struct login_info fake_item;
+ struct group *group;
+ int i;
+ char *at;
+
+ /*
+ * If a token has the magic value "ALL" the match always succeeds.
+ * Otherwise, return YES if the token fully matches the username, if the
+ * token is a group that contains the username, or if the token is the
+ * name of the user's primary group.
+ */
+
+ if ((at = strchr(tok + 1, '@')) != 0) { /* split user@host pattern */
+ *at = 0;
+ fake_item.from = myhostname();
+ return (user_match(tok, item) && from_match(at + 1, &fake_item));
+ } else if (tok[0] == '@') { /* netgroup */
+ return (netgroup_match(tok + 1, (char *) 0, string));
+ } else if (string_match(tok, string)) { /* ALL or exact match */
+ return (YES);
+ } else if ((group = getgrnam(tok))) { /* try group membership */
+ if (item->user->pw_gid == group->gr_gid)
+ return (YES);
+ for (i = 0; group->gr_mem[i]; i++)
+ if (strcasecmp(string, group->gr_mem[i]) == 0)
+ return (YES);
+ }
+ return (NO);
+}
+
+/* from_match - match a host or tty against a list of tokens */
+
+static int from_match(char *tok, struct login_info *item)
+{
+ char *string = item->from;
+ int tok_len;
+ int str_len;
+
+ /*
+ * If a token has the magic value "ALL" the match always succeeds. Return
+ * YES if the token fully matches the string. If the token is a domain
+ * name, return YES if it matches the last fields of the string. If the
+ * token has the magic value "LOCAL", return YES if the string does not
+ * contain a "." character. If the token is a network number, return YES
+ * if it matches the head of the string.
+ */
+
+ if (tok[0] == '@') { /* netgroup */
+ return (netgroup_match(tok + 1, string, (char *) 0));
+ } else if (string_match(tok, string)) { /* ALL or exact match */
+ return (YES);
+ } else if (tok[0] == '.') { /* domain: match last fields */
+ if ((str_len = strlen(string)) > (tok_len = strlen(tok))
+ && strcasecmp(tok, string + str_len - tok_len) == 0)
+ return (YES);
+ } else if (strcasecmp(tok, "LOCAL") == 0) { /* local: no dots */
+ if (strchr(string, '.') == 0)
+ return (YES);
+#ifdef BROKEN_NETWORK_MATCH
+ } else if (tok[(tok_len = strlen(tok)) - 1] == '.' /* network */
+ && strncmp(tok, string, tok_len) == 0) {
+ return (YES);
+#else /* BROKEN_NETWORK_MATCH */
+ } else if (tok[(tok_len = strlen(tok)) - 1] == '.') {
+ /*
+ The code below does a more correct check if the address specified
+ by "string" starts from "tok".
+ 1998/01/27 Andrey V. Savochkin <saw@msu.ru>
+ */
+
+ struct hostent *h;
+ char hn[3+1+3+1+3+1+3+1+1];
+ int r;
+
+ h = gethostbyname(string);
+ if (h == NULL)
+ return (NO);
+ if (h->h_addrtype != AF_INET)
+ return (NO);
+ if (h->h_length != 4)
+ return (NO); /* only IPv4 addresses (SAW) */
+ r = snprintf(hn, sizeof(hn), "%u.%u.%u.%u.",
+ (unsigned char)h->h_addr[0], (unsigned char)h->h_addr[1],
+ (unsigned char)h->h_addr[2], (unsigned char)h->h_addr[3]);
+ if (r < 0 || r >= sizeof(hn))
+ return (NO);
+ if (!strncmp(tok, hn, tok_len))
+ return (YES);
+#endif /* BROKEN_NETWORK_MATCH */
+ }
+ return (NO);
+}
+
+/* string_match - match a string against one token */
+
+static int string_match(char *tok, char *string)
+{
+
+ /*
+ * If the token has the magic value "ALL" the match always succeeds.
+ * Otherwise, return YES if the token fully matches the string.
+ */
+
+ if (strcasecmp(tok, "ALL") == 0) { /* all: always matches */
+ return (YES);
+ } else if (strcasecmp(tok, string) == 0) { /* try exact match */
+ return (YES);
+ }
+ return (NO);
+}
+
+/* end of login_access.c */
+
+int strcasecmp(const char *s1, const char *s2)
+{
+ while ((toupper(*s1)==toupper(*s2)) && (*s1) && (*s2)) {s1++; s2++;}
+ return(toupper(*s1)-toupper(*s2));
+}
+
+/* --- public account management functions --- */
+
+PAM_EXTERN int pam_sm_acct_mgmt(pam_handle_t *pamh,int flags,int argc
+ ,const char **argv)
+{
+ struct login_info loginfo;
+ const char *user=NULL, *service=NULL;
+ char *from=NULL;
+ struct passwd *user_pw;
+
+ if ((pam_get_item(pamh, PAM_SERVICE, (const void **)&service)
+ != PAM_SUCCESS) || (service == NULL) || (*service == ' ')) {
+ _log_err("cannot find the service name");
+ return PAM_ABORT;
+ }
+
+ /* set username */
+
+ if (pam_get_user(pamh, &user, NULL) != PAM_SUCCESS || user == NULL
+ || *user == '\0') {
+ _log_err("cannot determine the user's name");
+ return PAM_USER_UNKNOWN;
+ }
+
+ /* remote host name */
+
+ if (pam_get_item(pamh, PAM_RHOST, (const void **)&from)
+ != PAM_SUCCESS) {
+ _log_err("cannot find the remote host name");
+ return PAM_ABORT;
+ }
+
+ if ((from==NULL) || (*from=='\0')) {
+
+ /* local login, set tty name */
+
+ if (pam_get_item(pamh, PAM_TTY, (const void **)&from) != PAM_SUCCESS
+ || from == NULL) {
+ D(("PAM_TTY not set, probing stdin"));
+ from = ttyname(STDIN_FILENO);
+ if (from == NULL) {
+ _log_err("couldn't get the tty name");
+ return PAM_ABORT;
+ }
+ if (pam_set_item(pamh, PAM_TTY, from) != PAM_SUCCESS) {
+ _log_err("couldn't set tty name");
+ return PAM_ABORT;
+ }
+ }
+ if (strncmp("/dev/",from,5) == 0) { /* strip leading /dev/ */
+ from += 5;
+ }
+
+ }
+
+ if ((user_pw=getpwnam(user))==NULL) return (PAM_USER_UNKNOWN);
+
+ /*
+ * Bundle up the arguments to avoid unnecessary clumsiness later on.
+ */
+ loginfo.user = user_pw;
+ loginfo.from = from;
+ loginfo.service = service;
+ loginfo.config_file = PAM_ACCESS_CONFIG;
+
+ /* parse the argument list */
+
+ if (!parse_args(&loginfo, argc, argv)) {
+ _log_err("failed to parse the module arguments");
+ return PAM_ABORT;
+ }
+
+ if (login_access(&loginfo)) {
+ return (PAM_SUCCESS);
+ } else {
+ _log_err("access denied for user `%s' from `%s'",user,from);
+ return (PAM_PERM_DENIED);
+ }
+}
+
+/* end of module definition */
+
+#ifdef PAM_STATIC
+
+/* static module data */
+
+struct pam_module _pam_access_modstruct = {
+ "pam_access",
+ NULL,
+ NULL,
+ pam_sm_acct_mgmt,
+ NULL,
+ NULL,
+ NULL
+};
+#endif
+
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