X-Git-Url: http://andersk.mit.edu/gitweb/openssh.git/blobdiff_plain/c390a3c87f62322aeb018c6a9c2b801e3cd2d4dc..c4f51837081fc00e2c67c70da918a948590cd392:/auth.c diff --git a/auth.c b/auth.c index de004515..6d999221 100644 --- a/auth.c +++ b/auth.c @@ -23,14 +23,14 @@ */ #include "includes.h" -RCSID("$OpenBSD: auth.c,v 1.36 2002/03/15 11:00:38 itojun Exp $"); +RCSID("$OpenBSD: auth.c,v 1.51 2003/11/21 11:57:02 djm Exp $"); #ifdef HAVE_LOGIN_H #include #endif -#if defined(HAVE_SHADOW_H) && !defined(DISABLE_SHADOW) +#ifdef USE_SHADOW #include -#endif /* defined(HAVE_SHADOW_H) && !defined(DISABLE_SHADOW) */ +#endif #ifdef HAVE_LIBGEN_H #include @@ -48,9 +48,17 @@ RCSID("$OpenBSD: auth.c,v 1.36 2002/03/15 11:00:38 itojun Exp $"); #include "bufaux.h" #include "uidswap.h" #include "tildexpand.h" +#include "misc.h" +#include "bufaux.h" +#include "packet.h" /* import */ extern ServerOptions options; +extern Buffer loginmsg; + +/* Debugging messages */ +Buffer auth_debug; +int auth_debug_init; /* * Check if the user is allowed to log in via ssh. If user is listed @@ -65,38 +73,57 @@ int allowed_user(struct passwd * pw) { struct stat st; - const char *hostname = NULL, *ipaddr = NULL; + const char *hostname = NULL, *ipaddr = NULL, *passwd = NULL; char *shell; int i; -#ifdef WITH_AIXAUTHENTICATE - char *loginmsg; -#endif /* WITH_AIXAUTHENTICATE */ -#if !defined(USE_PAM) && defined(HAVE_SHADOW_H) && \ - !defined(DISABLE_SHADOW) && defined(HAS_SHADOW_EXPIRE) - struct spwd *spw; +#ifdef USE_SHADOW + struct spwd *spw = NULL; +#endif /* Shouldn't be called if pw is NULL, but better safe than sorry... */ if (!pw || !pw->pw_name) return 0; - spw = getspnam(pw->pw_name); - if (spw != NULL) { - int days = time(NULL) / 86400; +#ifdef USE_SHADOW + if (!options.use_pam) + spw = getspnam(pw->pw_name); +#ifdef HAS_SHADOW_EXPIRE + if (!options.use_pam && spw != NULL && auth_shadow_acctexpired(spw)) + return 0; +#endif /* HAS_SHADOW_EXPIRE */ +#endif /* USE_SHADOW */ - /* Check account expiry */ - if ((spw->sp_expire >= 0) && (days > spw->sp_expire)) - return 0; + /* grab passwd field for locked account check */ +#ifdef USE_SHADOW + if (spw != NULL) + passwd = spw->sp_pwdp; +#else + passwd = pw->pw_passwd; +#endif + + /* check for locked account */ + if (!options.use_pam && passwd && *passwd) { + int locked = 0; - /* Check password expiry */ - if ((spw->sp_lstchg >= 0) && (spw->sp_max >= 0) && - (days > (spw->sp_lstchg + spw->sp_max))) +#ifdef LOCKED_PASSWD_STRING + if (strcmp(passwd, LOCKED_PASSWD_STRING) == 0) + locked = 1; +#endif +#ifdef LOCKED_PASSWD_PREFIX + if (strncmp(passwd, LOCKED_PASSWD_PREFIX, + strlen(LOCKED_PASSWD_PREFIX)) == 0) + locked = 1; +#endif +#ifdef LOCKED_PASSWD_SUBSTR + if (strstr(passwd, LOCKED_PASSWD_SUBSTR)) + locked = 1; +#endif + if (locked) { + logit("User %.100s not allowed because account is locked", + pw->pw_name); return 0; + } } -#else - /* Shouldn't be called if pw is NULL, but better safe than sorry... */ - if (!pw || !pw->pw_name) - return 0; -#endif /* * Get the shell from the password data. An empty shell field is @@ -106,41 +133,41 @@ allowed_user(struct passwd * pw) /* deny if shell does not exists or is not executable */ if (stat(shell, &st) != 0) { - log("User %.100s not allowed because shell %.100s does not exist", + logit("User %.100s not allowed because shell %.100s does not exist", pw->pw_name, shell); return 0; } if (S_ISREG(st.st_mode) == 0 || (st.st_mode & (S_IXOTH|S_IXUSR|S_IXGRP)) == 0) { - log("User %.100s not allowed because shell %.100s is not executable", + logit("User %.100s not allowed because shell %.100s is not executable", pw->pw_name, shell); return 0; } if (options.num_deny_users > 0 || options.num_allow_users > 0) { - hostname = get_canonical_hostname(options.verify_reverse_mapping); + hostname = get_canonical_hostname(options.use_dns); ipaddr = get_remote_ipaddr(); } /* Return false if user is listed in DenyUsers */ if (options.num_deny_users > 0) { for (i = 0; i < options.num_deny_users; i++) - if (match_user(pw->pw_name, hostname, ipaddr, + if (match_user(pw->pw_name, hostname, ipaddr, options.deny_users[i])) { - log("User %.100s not allowed because listed in DenyUsers", - pw->pw_name); + logit("User %.100s not allowed because listed in DenyUsers", + pw->pw_name); return 0; } } /* Return false if AllowUsers isn't empty and user isn't listed there */ if (options.num_allow_users > 0) { for (i = 0; i < options.num_allow_users; i++) - if (match_user(pw->pw_name, hostname, ipaddr, + if (match_user(pw->pw_name, hostname, ipaddr, options.allow_users[i])) break; /* i < options.num_allow_users iff we break for loop */ if (i >= options.num_allow_users) { - log("User %.100s not allowed because not listed in AllowUsers", + logit("User %.100s not allowed because not listed in AllowUsers", pw->pw_name); return 0; } @@ -148,7 +175,7 @@ allowed_user(struct passwd * pw) if (options.num_deny_groups > 0 || options.num_allow_groups > 0) { /* Get the user's group access list (primary and supplementary) */ if (ga_init(pw->pw_name, pw->pw_gid) == 0) { - log("User %.100s not allowed because not in any group", + logit("User %.100s not allowed because not in any group", pw->pw_name); return 0; } @@ -158,7 +185,7 @@ allowed_user(struct passwd * pw) if (ga_match(options.deny_groups, options.num_deny_groups)) { ga_free(); - log("User %.100s not allowed because a group is listed in DenyGroups", + logit("User %.100s not allowed because a group is listed in DenyGroups", pw->pw_name); return 0; } @@ -170,7 +197,7 @@ allowed_user(struct passwd * pw) if (!ga_match(options.allow_groups, options.num_allow_groups)) { ga_free(); - log("User %.100s not allowed because none of user's groups are listed in AllowGroups", + logit("User %.100s not allowed because none of user's groups are listed in AllowGroups", pw->pw_name); return 0; } @@ -178,19 +205,28 @@ allowed_user(struct passwd * pw) } #ifdef WITH_AIXAUTHENTICATE - if (loginrestrictions(pw->pw_name, S_RLOGIN, NULL, &loginmsg) != 0) { - if (loginmsg && *loginmsg) { - /* Remove embedded newlines (if any) */ - char *p; - for (p = loginmsg; *p; p++) { - if (*p == '\n') - *p = ' '; + /* + * Don't check loginrestrictions() for root account (use + * PermitRootLogin to control logins via ssh), or if running as + * non-root user (since loginrestrictions will always fail). + */ + if ((pw->pw_uid != 0) && (geteuid() == 0)) { + char *msg; + + if (loginrestrictions(pw->pw_name, S_RLOGIN, NULL, &msg) != 0) { + int loginrestrict_errno = errno; + + if (msg && *msg) { + buffer_append(&loginmsg, msg, strlen(msg)); + aix_remove_embedded_newlines(msg); + logit("Login restricted for %s: %.100s", + pw->pw_name, msg); } - /* Remove trailing newline */ - *--p = '\0'; - log("Login restricted for %s: %.100s", pw->pw_name, loginmsg); + /* Don't fail if /etc/nologin set */ + if (!(loginrestrict_errno == EPERM && + stat(_PATH_NOLOGIN, &st) == 0)) + return 0; } - return 0; } #endif /* WITH_AIXAUTHENTICATE */ @@ -198,14 +234,6 @@ allowed_user(struct passwd * pw) return 1; } -Authctxt * -authctxt_new(void) -{ - Authctxt *authctxt = xmalloc(sizeof(*authctxt)); - memset(authctxt, 0, sizeof(*authctxt)); - return authctxt; -} - void auth_log(Authctxt *authctxt, int authenticated, char *method, char *info) { @@ -217,7 +245,7 @@ auth_log(Authctxt *authctxt, int authenticated, char *method, char *info) !authctxt->valid || authctxt->failures >= AUTH_FAIL_LOG || strcmp(method, "password") == 0) - authlog = log; + authlog = logit; if (authctxt->postponed) authmsg = "Postponed"; @@ -232,6 +260,11 @@ auth_log(Authctxt *authctxt, int authenticated, char *method, char *info) get_remote_ipaddr(), get_remote_port(), info); + +#ifdef CUSTOM_FAILED_LOGIN + if (authenticated == 0 && strcmp(method, "password") == 0) + record_failed_login(authctxt->user, "ssh"); +#endif } /* @@ -250,12 +283,12 @@ auth_root_allowed(char *method) break; case PERMIT_FORCED_ONLY: if (forced_command) { - log("Root login accepted for forced command."); + logit("Root login accepted for forced command."); return 1; } break; } - log("ROOT LOGIN REFUSED FROM %.200s", get_remote_ipaddr()); + logit("ROOT LOGIN REFUSED FROM %.200s", get_remote_ipaddr()); return 0; } @@ -347,7 +380,7 @@ check_key_in_hostfiles(struct passwd *pw, Key *key, const char *host, (stat(user_hostfile, &st) == 0) && ((st.st_uid != 0 && st.st_uid != pw->pw_uid) || (st.st_mode & 022) != 0)) { - log("Authentication refused for %.100s: " + logit("Authentication refused for %.100s: " "bad owner or modes for %.200s", pw->pw_name, user_hostfile); } else { @@ -368,7 +401,7 @@ check_key_in_hostfiles(struct passwd *pw, Key *key, const char *host, /* * Check a given file for security. This is defined as all components - * of the path to the file must either be owned by either the owner of + * of the path to the file must be owned by either the owner of * of the file or root and no directories must be group or world writable. * * XXX Should any specific check be done for sym links ? @@ -385,6 +418,7 @@ secure_filename(FILE *f, const char *file, struct passwd *pw, uid_t uid = pw->pw_uid; char buf[MAXPATHLEN], homedir[MAXPATHLEN]; char *cp; + int comparehome = 0; struct stat st; if (realpath(file, buf) == NULL) { @@ -392,11 +426,8 @@ secure_filename(FILE *f, const char *file, struct passwd *pw, strerror(errno)); return -1; } - if (realpath(pw->pw_dir, homedir) == NULL) { - snprintf(err, errlen, "realpath %s failed: %s", pw->pw_dir, - strerror(errno)); - return -1; - } + if (realpath(pw->pw_dir, homedir) != NULL) + comparehome = 1; /* check the open file to avoid races */ if (fstat(fileno(f), &st) < 0 || @@ -425,7 +456,7 @@ secure_filename(FILE *f, const char *file, struct passwd *pw, } /* If are passed the homedir then we can stop */ - if (strcmp(homedir, buf) == 0) { + if (comparehome && strcmp(homedir, buf) == 0) { debug3("secure_filename: terminating check at '%s'", buf); break; @@ -439,3 +470,106 @@ secure_filename(FILE *f, const char *file, struct passwd *pw, } return 0; } + +struct passwd * +getpwnamallow(const char *user) +{ +#ifdef HAVE_LOGIN_CAP + extern login_cap_t *lc; +#ifdef BSD_AUTH + auth_session_t *as; +#endif +#endif + struct passwd *pw; + + pw = getpwnam(user); + if (pw == NULL) { + logit("Illegal user %.100s from %.100s", + user, get_remote_ipaddr()); +#ifdef CUSTOM_FAILED_LOGIN + record_failed_login(user, "ssh"); +#endif + return (NULL); + } + if (!allowed_user(pw)) + return (NULL); +#ifdef HAVE_LOGIN_CAP + if ((lc = login_getclass(pw->pw_class)) == NULL) { + debug("unable to get login class: %s", user); + return (NULL); + } +#ifdef BSD_AUTH + if ((as = auth_open()) == NULL || auth_setpwd(as, pw) != 0 || + auth_approval(as, lc, pw->pw_name, "ssh") <= 0) { + debug("Approval failure for %s", user); + pw = NULL; + } + if (as != NULL) + auth_close(as); +#endif +#endif + if (pw != NULL) + return (pwcopy(pw)); + return (NULL); +} + +void +auth_debug_add(const char *fmt,...) +{ + char buf[1024]; + va_list args; + + if (!auth_debug_init) + return; + + va_start(args, fmt); + vsnprintf(buf, sizeof(buf), fmt, args); + va_end(args); + buffer_put_cstring(&auth_debug, buf); +} + +void +auth_debug_send(void) +{ + char *msg; + + if (!auth_debug_init) + return; + while (buffer_len(&auth_debug)) { + msg = buffer_get_string(&auth_debug, NULL); + packet_send_debug("%s", msg); + xfree(msg); + } +} + +void +auth_debug_reset(void) +{ + if (auth_debug_init) + buffer_clear(&auth_debug); + else { + buffer_init(&auth_debug); + auth_debug_init = 1; + } +} + +struct passwd * +fakepw(void) +{ + static struct passwd fake; + + memset(&fake, 0, sizeof(fake)); + fake.pw_name = "NOUSER"; + fake.pw_passwd = + "$2a$06$r3.juUaHZDlIbQaO2dS9FuYxL1W9M81R1Tc92PoSNmzvpEqLkLGrK"; + fake.pw_gecos = "NOUSER"; + fake.pw_uid = -1; + fake.pw_gid = -1; +#ifdef HAVE_PW_CLASS_IN_PASSWD + fake.pw_class = ""; +#endif + fake.pw_dir = "/nonexist"; + fake.pw_shell = "/nonexist"; + + return (&fake); +}