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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 12:50:00 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 12:50:00 +0000 |
commit | 333f7ecfa3e040191c66b2b92f6c117ca2cbac1d (patch) | |
tree | 178a8f140927896970f47930dae9213161268f10 /src/login_nopam.c | |
parent | Initial commit. (diff) | |
download | shadow-333f7ecfa3e040191c66b2b92f6c117ca2cbac1d.tar.xz shadow-333f7ecfa3e040191c66b2b92f6c117ca2cbac1d.zip |
Adding upstream version 1:4.8.1.upstream/1%4.8.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | src/login_nopam.c | 336 |
1 files changed, 336 insertions, 0 deletions
diff --git a/src/login_nopam.c b/src/login_nopam.c new file mode 100644 index 0000000..68a3775 --- /dev/null +++ b/src/login_nopam.c @@ -0,0 +1,336 @@ +/* Taken from logdaemon-5.0, only minimal changes. --marekm */ + +/************************************************************************ +* 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. +************************************************************************/ + +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif + +#ifndef USE_PAM +#ident "$Id$" + +#include "prototypes.h" + /* + * 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. + */ +#include <sys/types.h> +#include <stdio.h> +#include <syslog.h> +#include <ctype.h> +#ifdef HAVE_NETDB_H +#include <netdb.h> +#endif +#include <grp.h> +#ifdef PRIMARY_GROUP_MATCH +#include <pwd.h> +#endif +#include <errno.h> +#include <string.h> +#include <unistd.h> +#include <stdlib.h> +#include <sys/socket.h> +#include <netinet/in.h> +#include <arpa/inet.h> /* for inet_ntoa() */ + +#if !defined(MAXHOSTNAMELEN) || (MAXHOSTNAMELEN < 64) +#undef MAXHOSTNAMELEN +#define MAXHOSTNAMELEN 256 +#endif + + /* Path name of the access control file. */ +#ifndef TABLE +#define TABLE "/etc/login.access" +#endif + +/* Delimiters for fields and for lists of users, ttys or hosts. */ +static char fs[] = ":"; /* field separator */ +static char sep[] = ", \t"; /* list-element separator */ + +static bool list_match (char *list, const char *item, bool (*match_fn) (const char *, const char *)); +static bool user_match (const char *tok, const char *string); +static bool from_match (const char *tok, const char *string); +static bool string_match (const char *tok, const char *string); +static const char *resolve_hostname (const char *string); + +/* login_access - match username/group and host/tty with access control file */ +int login_access (const char *user, const char *from) +{ + 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 */ + bool match = false; + + /* + * 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. + */ + fp = fopen (TABLE, "r"); + if (NULL != fp) { + int lineno = 0; /* for diagnostics */ + while ( !match + && (fgets (line, (int) sizeof (line), fp) == line)) { + int end; + lineno++; + end = (int) strlen (line) - 1; + if (line[end] != '\n') { + SYSLOG ((LOG_ERR, + "%s: line %d: missing newline or line too long", + TABLE, 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)) == NULL) + || ((users = strtok ((char *) 0, fs)) == NULL) + || ((froms = strtok ((char *) 0, fs)) == NULL) + || (strtok ((char *) 0, fs) != NULL)) { + SYSLOG ((LOG_ERR, + "%s: line %d: bad field count", + TABLE, lineno)); + continue; + } + if (perm[0] != '+' && perm[0] != '-') { + SYSLOG ((LOG_ERR, + "%s: line %d: bad first field", + TABLE, lineno)); + continue; + } + match = ( list_match (froms, from, from_match) + && list_match (users, user, user_match)); + } + (void) fclose (fp); + } else if (errno != ENOENT) { + int err = errno; + SYSLOG ((LOG_ERR, "cannot open %s: %s", TABLE, strerror (err))); + } + return (!match || (line[0] == '+'))?1:0; +} + +/* list_match - match an item against a list of tokens with exceptions */ +static bool list_match (char *list, const char *item, bool (*match_fn) (const char *, const char*)) +{ + char *tok; + bool match = false; + + /* + * 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 != NULL; tok = strtok ((char *) 0, sep)) { + if (strcasecmp (tok, "EXCEPT") == 0) { /* EXCEPT: give up */ + break; + } + match = (*match_fn) (tok, item); + if (match) { + break; + } + } + + /* Process exceptions to matches. */ + if (match) { + while ( ((tok = strtok ((char *) 0, sep)) != NULL) + && (strcasecmp (tok, "EXCEPT") != 0)) + /* VOID */ ; + if (tok == 0 || !list_match ((char *) 0, item, match_fn)) { + return (match); + } + } + return false; +} + +/* myhostname - figure out local machine name */ +static char *myhostname (void) +{ + static char name[MAXHOSTNAMELEN + 1] = ""; + + if (name[0] == '\0') { + gethostname (name, sizeof (name)); + name[MAXHOSTNAMELEN] = '\0'; + } + return (name); +} + +#if HAVE_INNETGR +/* netgroup_match - match group against machine or user */ +static bool +netgroup_match (const char *group, const char *machine, const char *user) +{ + static char *mydomain = (char *)0; + + if (mydomain == (char *)0) { + static char domain[MAXHOSTNAMELEN + 1]; + + getdomainname (domain, MAXHOSTNAMELEN); + mydomain = domain; + } + + return (innetgr (group, machine, user, mydomain) != 0); +} +#endif + +/* user_match - match a username against one token */ +static bool user_match (const char *tok, const char *string) +{ + struct group *group; + +#ifdef PRIMARY_GROUP_MATCH + struct passwd *userinf; +#endif + char *at; + + /* + * If a token has the magic value "ALL" the match always succeeds. + * Otherwise, return true if the token fully matches the username, or if + * the token is a group that contains the username. + */ + at = strchr (tok + 1, '@'); + if (NULL != at) { /* split user@host pattern */ + *at = '\0'; + return ( user_match (tok, string) + && from_match (at + 1, myhostname ())); +#if HAVE_INNETGR + } else if (tok[0] == '@') { /* netgroup */ + return (netgroup_match (tok + 1, (char *) 0, string)); +#endif + } else if (string_match (tok, string)) { /* ALL or exact match */ + return true; + /* local, no need for xgetgrnam */ + } else if ((group = getgrnam (tok)) != NULL) { /* try group membership */ + int i; + for (i = 0; NULL != group->gr_mem[i]; i++) { + if (strcasecmp (string, group->gr_mem[i]) == 0) { + return true; + } + } +#ifdef PRIMARY_GROUP_MATCH + /* + * If the string is an user whose initial GID matches the token, + * accept it. May avoid excessively long lines in /etc/group. + * Radu-Adrian Feurdean <raf@licj.soroscj.ro> + * + * XXX - disabled by default for now. Need to verify that + * getpwnam() doesn't have some nasty side effects. --marekm + */ + /* local, no need for xgetpwnam */ + userinf = getpwnam (string); + if (NULL != userinf) { + if (userinf->pw_gid == group->gr_gid) { + return true; + } + } +#endif + } + return false; +} + +static const char *resolve_hostname (const char *string) +{ + /* + * Resolve hostname to numeric IP address, as suggested + * by Dave Hagewood <admin@arrowweb.com>. --marekm + */ + struct hostent *hp; + + hp = gethostbyname (string); + if (NULL != hp) { + return inet_ntoa (*((struct in_addr *) *(hp->h_addr_list))); + } + + SYSLOG ((LOG_ERR, "%s - unknown host", string)); + return string; +} + +/* from_match - match a host or tty against a list of tokens */ + +static bool from_match (const char *tok, const char *string) +{ + size_t tok_len; + + /* + * If a token has the magic value "ALL" the match always succeeds. Return + * true if the token fully matches the string. If the token is a domain + * name, return true if it matches the last fields of the string. If the + * token has the magic value "LOCAL", return true if the string does not + * contain a "." character. If the token is a network number, return true + * if it matches the head of the string. + */ +#if HAVE_INNETGR + if (tok[0] == '@') { /* netgroup */ + return (netgroup_match (tok + 1, string, (char *) 0)); + } else +#endif + if (string_match (tok, string)) { /* ALL or exact match */ + return true; + } else if (tok[0] == '.') { /* domain: match last fields */ + size_t str_len; + str_len = strlen (string); + tok_len = strlen (tok); + if ( (str_len > tok_len) + && (strcasecmp (tok, string + str_len - tok_len) == 0)) { + return true; + } + } else if (strcasecmp (tok, "LOCAL") == 0) { /* local: no dots */ + if (strchr (string, '.') == NULL) { + return true; + } + } else if ( (tok[(tok_len = strlen (tok)) - 1] == '.') /* network */ + && (strncmp (tok, resolve_hostname (string), tok_len) == 0)) { + return true; + } + return false; +} + +/* string_match - match a string against one token */ +static bool string_match (const char *tok, const char *string) +{ + + /* + * If the token has the magic value "ALL" the match always succeeds. + * Otherwise, return true if the token fully matches the string. + */ + if (strcasecmp (tok, "ALL") == 0) { /* all: always matches */ + return true; + } else if (strcasecmp (tok, string) == 0) { /* try exact match */ + return true; + } + return false; +} + +#else /* !USE_PAM */ +extern int errno; /* warning: ANSI C forbids an empty source file */ +#endif /* !USE_PAM */ |