]> andersk Git - gssapi-openssh.git/blobdiff - openssh/auth.c
authctxt->user should never be null but add a test just to be sure
[gssapi-openssh.git] / openssh / auth.c
index 26dce5b670ab3792e363d779285586a200a6c7ee..e1f4681d3cf5b0c7c71c19dda845b3408f8c1ac3 100644 (file)
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: auth.c,v 1.35 2002/03/01 13:12:10 markus Exp $");
+RCSID("$OpenBSD: auth.c,v 1.51 2003/11/21 11:57:02 djm Exp $");
 
 #ifdef HAVE_LOGIN_H
 #include <login.h>
 #endif
-#if defined(HAVE_SHADOW_H) && !defined(DISABLE_SHADOW)
+#ifdef USE_SHADOW
 #include <shadow.h>
-#endif /* defined(HAVE_SHADOW_H) && !defined(DISABLE_SHADOW) */
+#endif
 
 #ifdef HAVE_LIBGEN_H
 #include <libgen.h>
@@ -48,9 +48,17 @@ RCSID("$OpenBSD: auth.c,v 1.35 2002/03/01 13:12:10 markus 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
@@ -106,40 +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 (!((st.st_mode & S_IFREG) && (st.st_mode & (S_IXOTH|S_IXUSR|S_IXGRP)))) {
-               log("User %.100s not allowed because shell %.100s is not executable",
+       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);
                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;
                }
@@ -147,7 +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;
                }
@@ -157,7 +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;
                        }
@@ -169,7 +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;
                        }
@@ -177,19 +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 */
 
@@ -197,14 +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)
 {
@@ -216,7 +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";
@@ -227,10 +256,15 @@ auth_log(Authctxt *authctxt, int authenticated, char *method, char *info)
            authmsg,
            method,
            authctxt->valid ? "" : "illegal user ",
-           authctxt->user,
+           (authctxt->user && authctxt->user[0]) ? authctxt->user : "<implicit>",
            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
 }
 
 /*
@@ -249,12 +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;
 }
 
@@ -346,7 +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 {
@@ -367,7 +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 ?
@@ -384,6 +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) {
@@ -391,11 +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 ||
@@ -424,7 +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;
@@ -438,3 +470,107 @@ 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 && user[0]) ? user : "<implicit>",
+                     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);
+}
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