]> andersk Git - openssh.git/blobdiff - auth.c
- provos@cvs.openbsd.org 2002/03/18 03:41:08
[openssh.git] / auth.c
diff --git a/auth.c b/auth.c
index 84e0be76152647435eabea5c04a643cb46afe6ad..62c184ddf5aad608fb22f9b2c67c2d509e977cdf 100644 (file)
--- a/auth.c
+++ b/auth.c
@@ -23,7 +23,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: auth.c,v 1.26 2001/06/27 04:48:52 markus Exp $");
+RCSID("$OpenBSD: auth.c,v 1.38 2002/03/18 03:41:08 provos Exp $");
 
 #ifdef HAVE_LOGIN_H
 #include <login.h>
@@ -105,43 +105,61 @@ allowed_user(struct passwd * pw)
        shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
 
        /* deny if shell does not exists or is not executable */
-       if (stat(shell, &st) != 0)
+       if (stat(shell, &st) != 0) {
+               log("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))))
+       }
+       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",
+                   pw->pw_name, shell);
                return 0;
+       }
 
        if (options.num_deny_users > 0 || options.num_allow_users > 0) {
-               hostname = get_canonical_hostname(options.reverse_mapping_check);
+               hostname = get_canonical_hostname(options.verify_reverse_mapping);
                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,
-                           options.deny_users[i]))
+                       if (match_user(pw->pw_name, hostname, ipaddr,
+                           options.deny_users[i])) {
+                               log("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)
+               if (i >= options.num_allow_users) {
+                       log("User %.100s not allowed because not listed in AllowUsers",
+                           pw->pw_name);
                        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)
+               if (ga_init(pw->pw_name, pw->pw_gid) == 0) {
+                       log("User %.100s not allowed because not in any group",
+                           pw->pw_name);
                        return 0;
+               }
 
                /* Return false if one of user's groups is listed in DenyGroups */
                if (options.num_deny_groups > 0)
                        if (ga_match(options.deny_groups,
                            options.num_deny_groups)) {
                                ga_free();
+                               log("User %.100s not allowed because a group is listed in DenyGroups",
+                                   pw->pw_name);
                                return 0;
                        }
                /*
@@ -152,6 +170,8 @@ 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",
+                                   pw->pw_name);
                                return 0;
                        }
                ga_free();
@@ -208,7 +228,7 @@ auth_log(Authctxt *authctxt, int authenticated, char *method, char *info)
            authmsg,
            method,
            authctxt->valid ? "" : "illegal user ",
-           authctxt->valid && authctxt->pw->pw_uid == 0 ? "ROOT" : authctxt->user,
+           authctxt->user,
            get_remote_ipaddr(),
            get_remote_port(),
            info);
@@ -272,7 +292,7 @@ expand_filename(const char *filename, struct passwd *pw)
                }
                if (cp[0] == '%' && cp[1] == 'u') {
                        buffer_append(&buffer, pw->pw_name,
-                            strlen(pw->pw_name));
+                           strlen(pw->pw_name));
                        cp++;
                        continue;
                }
@@ -315,7 +335,7 @@ check_key_in_hostfiles(struct passwd *pw, Key *key, const char *host,
        Key *found;
        char *user_hostfile;
        struct stat st;
-       int host_status;
+       HostStatus host_status;
 
        /* Check if we know the host and its host key. */
        found = key_new(key->type);
@@ -326,7 +346,7 @@ check_key_in_hostfiles(struct passwd *pw, Key *key, const char *host,
                if (options.strict_modes &&
                    (stat(user_hostfile, &st) == 0) &&
                    ((st.st_uid != 0 && st.st_uid != pw->pw_uid) ||
-                    (st.st_mode & 022) != 0)) {
+                   (st.st_mode & 022) != 0)) {
                        log("Authentication refused for %.100s: "
                            "bad owner or modes for %.200s",
                            pw->pw_name, user_hostfile);
@@ -363,18 +383,20 @@ secure_filename(FILE *f, const char *file, struct passwd *pw,
     char *err, size_t errlen)
 {
        uid_t uid = pw->pw_uid;
-       char homedir[MAXPATHLEN];
-       char buf[MAXPATHLEN];
+       char buf[MAXPATHLEN], homedir[MAXPATHLEN];
        char *cp;
        struct stat st;
 
-       strlcpy(homedir, dirname(pw->pw_dir), sizeof(homedir));
-
        if (realpath(file, buf) == NULL) {
                snprintf(err, errlen, "realpath %s failed: %s", file,
                    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;
+       }
 
        /* check the open file to avoid races */
        if (fstat(fileno(f), &st) < 0 ||
@@ -385,8 +407,6 @@ secure_filename(FILE *f, const char *file, struct passwd *pw,
                return -1;
        }
 
-       debug3("secure_filename: terminating check at '%s'", homedir);
-
        /* for each component of the canonical path, walking upwards */
        for (;;) {
                if ((cp = dirname(buf)) == NULL) {
@@ -395,19 +415,21 @@ secure_filename(FILE *f, const char *file, struct passwd *pw,
                }
                strlcpy(buf, cp, sizeof(buf));
 
-               /* If are passed the homedir then we can stop */
-               if (strcmp(buf, homedir) == 0)
-                       break;
-
                debug3("secure_filename: checking '%s'", buf);
                if (stat(buf, &st) < 0 ||
                    (st.st_uid != 0 && st.st_uid != uid) ||
                    (st.st_mode & 022) != 0) {
-                       snprintf(err, errlen, 
+                       snprintf(err, errlen,
                            "bad ownership or modes for directory %s", buf);
                        return -1;
                }
 
+               /* If are passed the homedir then we can stop */
+               if (strcmp(homedir, buf) == 0) {
+                       debug3("secure_filename: terminating check at '%s'",
+                           buf);
+                       break;
+               }
                /*
                 * dirname should always complete with a "/" path,
                 * but we can be paranoid and check for "." too
@@ -417,3 +439,35 @@ 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 || !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(NULL, lc, pw->pw_name, "ssh") <= 0) {
+               debug("Approval failure for %s", user);
+               pw = NULL;
+       }
+       if (as != NULL)
+               auth_close(as);
+#endif
+#endif
+       return (pw);
+}
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