X-Git-Url: http://andersk.mit.edu/gitweb/openssh.git/blobdiff_plain/2362db19c34ff0d1b04e3b2656523d93089a4a15..HEAD:/auth.c diff --git a/auth.c b/auth.c index 02967287..da87807a 100644 --- a/auth.c +++ b/auth.c @@ -1,3 +1,4 @@ +/* $OpenBSD: auth.c,v 1.83 2010/01/13 23:47:26 djm Exp $ */ /* * Copyright (c) 2000 Markus Friedl. All rights reserved. * @@ -23,38 +24,58 @@ */ #include "includes.h" -RCSID("$OpenBSD: auth.c,v 1.50 2003/09/23 20:17:11 markus Exp $"); +#include +#include +#include + +#include + +#include +#include +#ifdef HAVE_PATHS_H +# include +#endif +#include #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 #endif +#include +#include +#include +#include #include "xmalloc.h" #include "match.h" #include "groupaccess.h" #include "log.h" +#include "buffer.h" #include "servconf.h" +#include "key.h" +#include "hostfile.h" #include "auth.h" #include "auth-options.h" #include "canohost.h" -#include "buffer.h" -#include "bufaux.h" #include "uidswap.h" -#include "tildexpand.h" #include "misc.h" -#include "bufaux.h" #include "packet.h" +#include "loginrec.h" +#ifdef GSSAPI +#include "ssh-gss.h" +#endif +#include "monitor_wrap.h" /* import */ extern ServerOptions options; +extern int use_privsep; extern Buffer loginmsg; +extern struct passwd *privsep_pw; /* Debugging messages */ Buffer auth_debug; @@ -74,9 +95,9 @@ allowed_user(struct passwd * pw) { struct stat st; const char *hostname = NULL, *ipaddr = NULL, *passwd = NULL; - char *shell; - int i; -#if defined(HAVE_SHADOW_H) && !defined(DISABLE_SHADOW) + char *shell, *tmp, *chroot_path; + u_int i; +#ifdef USE_SHADOW struct spwd *spw = NULL; #endif @@ -84,53 +105,27 @@ allowed_user(struct passwd * pw) if (!pw || !pw->pw_name) return 0; -#if defined(HAVE_SHADOW_H) && !defined(DISABLE_SHADOW) +#ifdef USE_SHADOW if (!options.use_pam) spw = getspnam(pw->pw_name); #ifdef HAS_SHADOW_EXPIRE -#define DAY (24L * 60 * 60) /* 1 day in seconds */ - if (!options.use_pam && spw != NULL) { - time_t today; - - today = time(NULL) / DAY; - debug3("allowed_user: today %d sp_expire %d sp_lstchg %d" - " sp_max %d", (int)today, (int)spw->sp_expire, - (int)spw->sp_lstchg, (int)spw->sp_max); - - /* - * We assume account and password expiration occurs the - * day after the day specified. - */ - if (spw->sp_expire != -1 && today > spw->sp_expire) { - logit("Account %.100s has expired", pw->pw_name); - return 0; - } - - if (spw->sp_lstchg == 0) { - logit("User %.100s password has expired (root forced)", - pw->pw_name); - return 0; - } - - if (spw->sp_max != -1 && - today > spw->sp_lstchg + spw->sp_max) { - logit("User %.100s password has expired (password aged)", - pw->pw_name); - return 0; - } - } + if (!options.use_pam && spw != NULL && auth_shadow_acctexpired(spw)) + return 0; #endif /* HAS_SHADOW_EXPIRE */ -#endif /* defined(HAVE_SHADOW_H) && !defined(DISABLE_SHADOW) */ +#endif /* USE_SHADOW */ - /* grab passwd field for locked account check */ -#if defined(HAVE_SHADOW_H) && !defined(DISABLE_SHADOW) + /* grab passwd field for locked account check */ + passwd = pw->pw_passwd; +#ifdef USE_SHADOW if (spw != NULL) - passwd = spw->sp_pwdp; +#ifdef USE_LIBIAF + passwd = get_iaf_password(pw); #else - passwd = pw->pw_passwd; + passwd = spw->sp_pwdp; +#endif /* USE_LIBIAF */ #endif - /* check for locked account */ + /* check for locked account */ if (!options.use_pam && passwd && *passwd) { int locked = 0; @@ -147,6 +142,9 @@ allowed_user(struct passwd * pw) if (strstr(passwd, LOCKED_PASSWD_SUBSTR)) locked = 1; #endif +#ifdef USE_LIBIAF + free(passwd); +#endif /* USE_LIBIAF */ if (locked) { logit("User %.100s not allowed because account is locked", pw->pw_name); @@ -158,22 +156,43 @@ allowed_user(struct passwd * pw) * Get the shell from the password data. An empty shell field is * legal, and means /bin/sh. */ - shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell; + shell = xstrdup((pw->pw_shell[0] == '\0') ? + _PATH_BSHELL : pw->pw_shell); + + /* + * Amend shell if chroot is requested. + */ + if (options.chroot_directory != NULL && + strcasecmp(options.chroot_directory, "none") != 0) { + tmp = tilde_expand_filename(options.chroot_directory, + pw->pw_uid); + chroot_path = percent_expand(tmp, "h", pw->pw_dir, + "u", pw->pw_name, (char *)NULL); + xfree(tmp); + xasprintf(&tmp, "%s/%s", chroot_path, shell); + xfree(shell); + shell = tmp; + free(chroot_path); + } /* deny if shell does not exists or is not executable */ if (stat(shell, &st) != 0) { logit("User %.100s not allowed because shell %.100s does not exist", pw->pw_name, shell); + xfree(shell); return 0; } if (S_ISREG(st.st_mode) == 0 || (st.st_mode & (S_IXOTH|S_IXUSR|S_IXGRP)) == 0) { logit("User %.100s not allowed because shell %.100s is not executable", pw->pw_name, shell); + xfree(shell); return 0; } + xfree(shell); - if (options.num_deny_users > 0 || options.num_allow_users > 0) { + if (options.num_deny_users > 0 || options.num_allow_users > 0 || + options.num_deny_groups > 0 || options.num_allow_groups > 0) { hostname = get_canonical_hostname(options.use_dns); ipaddr = get_remote_ipaddr(); } @@ -183,8 +202,9 @@ allowed_user(struct passwd * pw) for (i = 0; i < options.num_deny_users; i++) if (match_user(pw->pw_name, hostname, ipaddr, options.deny_users[i])) { - logit("User %.100s not allowed because listed in DenyUsers", - pw->pw_name); + logit("User %.100s from %.100s not allowed " + "because listed in DenyUsers", + pw->pw_name, hostname); return 0; } } @@ -196,16 +216,16 @@ allowed_user(struct passwd * pw) break; /* i < options.num_allow_users iff we break for loop */ if (i >= options.num_allow_users) { - logit("User %.100s not allowed because not listed in AllowUsers", - pw->pw_name); + logit("User %.100s from %.100s not allowed because " + "not listed in AllowUsers", pw->pw_name, hostname); return 0; } } 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) { - logit("User %.100s not allowed because not in any group", - pw->pw_name); + logit("User %.100s from %.100s not allowed because " + "not in any group", pw->pw_name, hostname); return 0; } @@ -214,8 +234,9 @@ allowed_user(struct passwd * pw) if (ga_match(options.deny_groups, options.num_deny_groups)) { ga_free(); - logit("User %.100s not allowed because a group is listed in DenyGroups", - pw->pw_name); + logit("User %.100s from %.100s not allowed " + "because a group is listed in DenyGroups", + pw->pw_name, hostname); return 0; } /* @@ -226,38 +247,18 @@ allowed_user(struct passwd * pw) if (!ga_match(options.allow_groups, options.num_allow_groups)) { ga_free(); - logit("User %.100s not allowed because none of user's groups are listed in AllowGroups", - pw->pw_name); + logit("User %.100s from %.100s not allowed " + "because none of user's groups are listed " + "in AllowGroups", pw->pw_name, hostname); return 0; } ga_free(); } -#ifdef WITH_AIXAUTHENTICATE - /* - * 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); - } - /* Don't fail if /etc/nologin set */ - if (!(loginrestrict_errno == EPERM && - stat(_PATH_NOLOGIN, &st) == 0)) - return 0; - } - } -#endif /* WITH_AIXAUTHENTICATE */ +#ifdef CUSTOM_SYS_AUTH_ALLOWED_USER + if (!sys_auth_allowed_user(pw, &loginmsg)) + return 0; +#endif /* We found no reason not to let this user try to log on... */ return 1; @@ -269,10 +270,13 @@ auth_log(Authctxt *authctxt, int authenticated, char *method, char *info) void (*authlog) (const char *fmt,...) = verbose; char *authmsg; + if (use_privsep && !mm_is_monitor() && !authctxt->postponed) + return; + /* Raise logging level */ if (authenticated == 1 || !authctxt->valid || - authctxt->failures >= AUTH_FAIL_LOG || + authctxt->failures >= options.max_authtries / 2 || strcmp(method, "password") == 0) authlog = logit; @@ -284,15 +288,28 @@ auth_log(Authctxt *authctxt, int authenticated, char *method, char *info) authlog("%s %s for %s%.100s from %.200s port %d%s", authmsg, method, - authctxt->valid ? "" : "illegal user ", + authctxt->valid ? "" : "invalid user ", authctxt->user, get_remote_ipaddr(), get_remote_port(), info); #ifdef CUSTOM_FAILED_LOGIN - if (authenticated == 0 && strcmp(method, "password") == 0) - record_failed_login(authctxt->user, "ssh"); + if (authenticated == 0 && !authctxt->postponed && + (strcmp(method, "password") == 0 || + strncmp(method, "keyboard-interactive", 20) == 0 || + strcmp(method, "challenge-response") == 0)) + record_failed_login(authctxt->user, + get_canonical_hostname(options.use_dns), "ssh"); +# ifdef WITH_AIXAUTHENTICATE + if (authenticated) + sys_auth_record_login(authctxt->user, + get_canonical_hostname(options.use_dns), "ssh", &loginmsg); +# endif +#endif +#ifdef SSH_AUDIT_EVENTS + if (authenticated == 0 && !authctxt->postponed) + audit_event(audit_classify_auth(method)); #endif } @@ -305,7 +322,6 @@ auth_root_allowed(char *method) switch (options.permit_root_login) { case PERMIT_YES: return 1; - break; case PERMIT_NO_PASSWD: if (strcmp(method, "password") != 0) return 1; @@ -329,64 +345,39 @@ auth_root_allowed(char *method) * * This returns a buffer allocated by xmalloc. */ -char * -expand_filename(const char *filename, struct passwd *pw) +static char * +expand_authorized_keys(const char *filename, struct passwd *pw) { - Buffer buffer; - char *file; - const char *cp; + char *file, ret[MAXPATHLEN]; + int i; - /* - * Build the filename string in the buffer by making the appropriate - * substitutions to the given file name. - */ - buffer_init(&buffer); - for (cp = filename; *cp; cp++) { - if (cp[0] == '%' && cp[1] == '%') { - buffer_append(&buffer, "%", 1); - cp++; - continue; - } - if (cp[0] == '%' && cp[1] == 'h') { - buffer_append(&buffer, pw->pw_dir, strlen(pw->pw_dir)); - cp++; - continue; - } - if (cp[0] == '%' && cp[1] == 'u') { - buffer_append(&buffer, pw->pw_name, - strlen(pw->pw_name)); - cp++; - continue; - } - buffer_append(&buffer, cp, 1); - } - buffer_append(&buffer, "\0", 1); + file = percent_expand(filename, "h", pw->pw_dir, + "u", pw->pw_name, (char *)NULL); /* * Ensure that filename starts anchored. If not, be backward * compatible and prepend the '%h/' */ - file = xmalloc(MAXPATHLEN); - cp = buffer_ptr(&buffer); - if (*cp != '/') - snprintf(file, MAXPATHLEN, "%s/%s", pw->pw_dir, cp); - else - strlcpy(file, cp, MAXPATHLEN); - - buffer_free(&buffer); - return file; + if (*file == '/') + return (file); + + i = snprintf(ret, sizeof(ret), "%s/%s", pw->pw_dir, file); + if (i < 0 || (size_t)i >= sizeof(ret)) + fatal("expand_authorized_keys: path too long"); + xfree(file); + return (xstrdup(ret)); } char * authorized_keys_file(struct passwd *pw) { - return expand_filename(options.authorized_keys_file, pw); + return expand_authorized_keys(options.authorized_keys_file, pw); } char * authorized_keys_file2(struct passwd *pw) { - return expand_filename(options.authorized_keys_file2, pw); + return expand_authorized_keys(options.authorized_keys_file2, pw); } /* return ok if key exists in sysfile or userfile */ @@ -440,7 +431,7 @@ check_key_in_hostfiles(struct passwd *pw, Key *key, const char *host, * * Returns 0 on success and -1 on failure */ -int +static int secure_filename(FILE *f, const char *file, struct passwd *pw, char *err, size_t errlen) { @@ -484,7 +475,7 @@ secure_filename(FILE *f, const char *file, struct passwd *pw, return -1; } - /* If are passed the homedir then we can stop */ + /* If are past the homedir then we can stop */ if (comparehome && strcmp(homedir, buf) == 0) { debug3("secure_filename: terminating check at '%s'", buf); @@ -500,6 +491,50 @@ secure_filename(FILE *f, const char *file, struct passwd *pw, return 0; } +FILE * +auth_openkeyfile(const char *file, struct passwd *pw, int strict_modes) +{ + char line[1024]; + struct stat st; + int fd; + FILE *f; + + /* + * Open the file containing the authorized keys + * Fail quietly if file does not exist + */ + if ((fd = open(file, O_RDONLY|O_NONBLOCK)) == -1) { + if (errno != ENOENT) + debug("Could not open keyfile '%s': %s", file, + strerror(errno)); + return NULL; + } + + if (fstat(fd, &st) < 0) { + close(fd); + return NULL; + } + if (!S_ISREG(st.st_mode)) { + logit("User %s authorized keys %s is not a regular file", + pw->pw_name, file); + close(fd); + return NULL; + } + unset_nonblock(fd); + if ((f = fdopen(fd, "r")) == NULL) { + close(fd); + return NULL; + } + if (options.strict_modes && + secure_filename(f, file, pw, line, sizeof(line)) != 0) { + fclose(f); + logit("Authentication refused: %s", line); + return NULL; + } + + return f; +} + struct passwd * getpwnamallow(const char *user) { @@ -511,13 +546,20 @@ getpwnamallow(const char *user) #endif struct passwd *pw; + parse_server_match_config(&options, user, + get_canonical_hostname(options.use_dns), get_remote_ipaddr()); + pw = getpwnam(user); if (pw == NULL) { - logit("Illegal user %.100s from %.100s", + logit("Invalid user %.100s from %.100s", user, get_remote_ipaddr()); #ifdef CUSTOM_FAILED_LOGIN - record_failed_login(user, "ssh"); + record_failed_login(user, + get_canonical_hostname(options.use_dns), "ssh"); #endif +#ifdef SSH_AUDIT_EVENTS + audit_event(SSH_INVALID_USER); +#endif /* SSH_AUDIT_EVENTS */ return (NULL); } if (!allowed_user(pw)) @@ -590,10 +632,10 @@ fakepw(void) memset(&fake, 0, sizeof(fake)); fake.pw_name = "NOUSER"; fake.pw_passwd = - "$2a$06$r3.juUaHZDlIbQaO2dS9FuYxL1W9M81R1Tc92PoSNmzvpEqLkLGrK"; + "$2a$06$r3.juUaHZDlIbQaO2dS9FuYxL1W9M81R1Tc92PoSNmzvpEqLkLGrK"; fake.pw_gecos = "NOUSER"; - fake.pw_uid = -1; - fake.pw_gid = -1; + fake.pw_uid = privsep_pw == NULL ? (uid_t)-1 : privsep_pw->pw_uid; + fake.pw_gid = privsep_pw == NULL ? (gid_t)-1 : privsep_pw->pw_gid; #ifdef HAVE_PW_CLASS_IN_PASSWD fake.pw_class = ""; #endif