]> andersk Git - openssh.git/blobdiff - auth1.c
- (djm) Merge BSD_AUTH support from Markus Friedl and David J. MacKenzie
[openssh.git] / auth1.c
diff --git a/auth1.c b/auth1.c
index 5e9b3aa5b4155baadf9b4ec74dd34ba38ae5bb46..beccf2b45a33ed7f6450bc42d4c31c9b7483c1c3 100644 (file)
--- a/auth1.c
+++ b/auth1.c
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: auth1.c,v 1.10 2001/01/07 19:06:25 markus Exp $");
-
-#ifdef HAVE_OSF_SIA
-# include <sia.h>
-# include <siad.h>
-#endif
+RCSID("$OpenBSD: auth1.c,v 1.17 2001/02/13 22:49:40 markus Exp $");
 
 #include "xmalloc.h"
 #include "rsa.h"
-#include "ssh.h"
+#include "ssh1.h"
 #include "packet.h"
 #include "buffer.h"
 #include "mpaux.h"
+#include "log.h"
 #include "servconf.h"
 #include "compat.h"
 #include "auth.h"
@@ -35,10 +31,6 @@ extern char *forced_command;
 #ifdef WITH_AIXAUTHENTICATE
 extern char *aixloginmsg;
 #endif /* WITH_AIXAUTHENTICATE */
-#ifdef HAVE_OSF_SIA
-extern int saved_argc;
-extern char **saved_argv;
-#endif /* HAVE_OSF_SIA */
 
 /*
  * convert ssh auth msg type into description
@@ -56,13 +48,12 @@ get_authname(int type)
                return "rhosts-rsa";
        case SSH_CMSG_AUTH_RHOSTS:
                return "rhosts";
+       case SSH_CMSG_AUTH_TIS:
+       case SSH_CMSG_AUTH_TIS_RESPONSE:
+               return "challenge-response";
 #ifdef KRB4
        case SSH_CMSG_AUTH_KERBEROS:
                return "kerberos";
-#endif
-#ifdef SKEY
-       case SSH_CMSG_AUTH_TIS_RESPONSE:
-               return "s/key";
 #endif
        }
        snprintf(buf, sizeof buf, "bad-auth-msg-%d", type);
@@ -70,27 +61,42 @@ get_authname(int type)
 }
 
 /*
- * read packets and try to authenticate local user 'luser'.
- * return if authentication is successful. not that pw == NULL
- * if the user does not exists or is not allowed to login.
- * each auth method has to 'fake' authentication for nonexisting
- * users.
+ * read packets, try to authenticate the user and
+ * return only if authentication is successful
  */
 void
-do_authloop(struct passwd * pw, char *luser)
+do_authloop(Authctxt *authctxt)
 {
        int authenticated = 0;
-       int attempt = 0;
        u_int bits;
        RSA *client_host_key;
        BIGNUM *n;
        char *client_user, *password;
-       char user[1024];
+       char info[1024];
        u_int dlen;
        int plen, nlen, elen;
        u_int ulen;
        int type = 0;
-       void (*authlog) (const char *fmt,...) = verbose;
+       struct passwd *pw = authctxt->pw;
+
+       debug("Attempting authentication for %s%.100s.",
+            authctxt->valid ? "" : "illegal user ", authctxt->user);
+
+       /* If the user has no password, accept authentication immediately. */
+       if (options.password_authentication &&
+#ifdef KRB4
+           (!options.kerberos_authentication || options.kerberos_or_local_passwd) &&
+#endif
+#ifdef USE_PAM
+           auth_pam_password(pw, "")) {
+#elif defined(HAVE_OSF_SIA)
+           0) {
+#else
+           auth_password(authctxt, "")) {
+#endif
+               auth_log(authctxt, 1, "without authentication", "");
+               return;
+       }
 
        /* Indicate that authentication is needed. */
        packet_start(SSH_SMSG_FAILURE);
@@ -99,11 +105,11 @@ do_authloop(struct passwd * pw, char *luser)
 
        client_user = NULL;
 
-       for (attempt = 1;; attempt++) {
+       for (;;) {
                /* default to fail */
                authenticated = 0;
 
-               strlcpy(user, "", sizeof user);
+               info[0] = '\0';
 
                /* Get a packet from the client. */
                type = packet_read(&plen);
@@ -120,7 +126,7 @@ do_authloop(struct passwd * pw, char *luser)
                                char *tgt = packet_get_string(&dlen);
                                packet_integrity_check(plen, 4 + dlen, type);
                                if (!auth_kerberos_tgt(pw, tgt))
-                                       verbose("Kerberos tgt REFUSED for %.100s", luser);
+                                       verbose("Kerberos tgt REFUSED for %.100s", authctxt->user);
                                xfree(tgt);
                        }
                        continue;
@@ -134,7 +140,7 @@ do_authloop(struct passwd * pw, char *luser)
                                char *token_string = packet_get_string(&dlen);
                                packet_integrity_check(plen, 4 + dlen, type);
                                if (!auth_afs_token(pw, token_string))
-                                       verbose("AFS token REFUSED for %.100s", luser);
+                                       verbose("AFS token REFUSED for %.100s", authctxt->user);
                                xfree(token_string);
                        }
                        continue;
@@ -142,7 +148,6 @@ do_authloop(struct passwd * pw, char *luser)
 #ifdef KRB4
                case SSH_CMSG_AUTH_KERBEROS:
                        if (!options.kerberos_authentication) {
-                               /* packet_get_all(); */
                                verbose("Kerberos authentication disabled.");
                                break;
                        } else {
@@ -152,17 +157,17 @@ do_authloop(struct passwd * pw, char *luser)
                                char *kdata = packet_get_string((u_int *) &auth.length);
                                packet_integrity_check(plen, 4 + auth.length, type);
 
-                               if (auth.length < MAX_KTXT_LEN)
-                                       memcpy(auth.dat, kdata, auth.length);
-                               xfree(kdata);
-
-                               if (pw != NULL) {
+                               if (authctxt->valid) {
+                                       if (auth.length < MAX_KTXT_LEN)
+                                               memcpy(auth.dat, kdata, auth.length);
                                        authenticated = auth_krb4(pw->pw_name, &auth, &tkt_user);
                                        if (authenticated) {
-                                               snprintf(user, sizeof user, " tktuser %s", tkt_user);
+                                               snprintf(info, sizeof info,
+                                                   " tktuser %.100s", tkt_user);
                                                xfree(tkt_user);
                                        }
                                }
+                               xfree(kdata);
                        }
                        break;
 #endif /* KRB4 */
@@ -184,7 +189,7 @@ do_authloop(struct passwd * pw, char *luser)
                        /* Try to authenticate using /etc/hosts.equiv and .rhosts. */
                        authenticated = auth_rhosts(pw, client_user);
 
-                       snprintf(user, sizeof user, " ruser %s", client_user);
+                       snprintf(info, sizeof info, " ruser %.100s", client_user);
                        break;
 
                case SSH_CMSG_AUTH_RHOSTS_RSA:
@@ -219,7 +224,7 @@ do_authloop(struct passwd * pw, char *luser)
                        authenticated = auth_rhosts_rsa(pw, client_user, client_host_key);
                        RSA_free(client_host_key);
 
-                       snprintf(user, sizeof user, " ruser %s", client_user);
+                       snprintf(info, sizeof info, " ruser %.100s", client_user);
                        break;
 
                case SSH_CMSG_AUTH_RSA:
@@ -253,36 +258,25 @@ do_authloop(struct passwd * pw, char *luser)
                        authenticated = auth_pam_password(pw, password);
 #elif defined(HAVE_OSF_SIA)
                        /* Do SIA auth with password */
-                       if (sia_validate_user(NULL, saved_argc, saved_argv, 
-                               get_canonical_hostname(), pw->pw_name, NULL, 0, 
-                               NULL, password) == SIASUCCESS) {
-                               authenticated = 1;
-                       }
+                       authenticated = auth_sia_password(authctxt->user, 
+                           password);
 #else /* !USE_PAM && !HAVE_OSF_SIA */
-                       /* Try authentication with the password. */
-                       authenticated = auth_password(pw, password);
+                       /* Try authentication with the password. */
+                       authenticated = auth_password(authctxt, password);
 #endif /* USE_PAM */
 
                        memset(password, 0, strlen(password));
                        xfree(password);
                        break;
 
-#ifdef SKEY
                case SSH_CMSG_AUTH_TIS:
                        debug("rcvd SSH_CMSG_AUTH_TIS");
-                       if (options.skey_authentication == 1) {
-                               char *skeyinfo = NULL;
-                               if (pw != NULL)
-                                       skeyinfo = skey_keyinfo(pw->pw_name);
-                               if (skeyinfo == NULL) {
-                                       debug("generating fake skeyinfo for %.100s.", luser);
-                                       skeyinfo = skey_fake_keyinfo(luser);
-                               }
-                               if (skeyinfo != NULL) {
-                                       /* we send our s/key- in tis-challenge messages */
-                                       debug("sending challenge '%s'", skeyinfo);
+                       if (options.challenge_reponse_authentication == 1) {
+                               char *challenge = get_challenge(authctxt, authctxt->style);
+                               if (challenge != NULL) {
+                                       debug("sending challenge '%s'", challenge);
                                        packet_start(SSH_SMSG_AUTH_TIS_CHALLENGE);
-                                       packet_put_cstring(skeyinfo);
+                                       packet_put_cstring(challenge);
                                        packet_send();
                                        packet_write_wait();
                                        continue;
@@ -291,22 +285,15 @@ do_authloop(struct passwd * pw, char *luser)
                        break;
                case SSH_CMSG_AUTH_TIS_RESPONSE:
                        debug("rcvd SSH_CMSG_AUTH_TIS_RESPONSE");
-                       if (options.skey_authentication == 1) {
+                       if (options.challenge_reponse_authentication == 1) {
                                char *response = packet_get_string(&dlen);
-                               debug("skey response == '%s'", response);
+                               debug("got response '%s'", response);
                                packet_integrity_check(plen, 4 + dlen, type);
-                               authenticated = (pw != NULL &&
-                                   skey_haskey(pw->pw_name) == 0 &&
-                                   skey_passcheck(pw->pw_name, response) != -1);
+                               authenticated = verify_response(authctxt, response);
+                               memset(response, 'r', dlen);
                                xfree(response);
                        }
                        break;
-#else
-               case SSH_CMSG_AUTH_TIS:
-                       /* TIS Authentication is unsupported */
-                       log("TIS authentication unsupported.");
-                       break;
-#endif
 
                default:
                        /*
@@ -316,53 +303,37 @@ do_authloop(struct passwd * pw, char *luser)
                        log("Unknown message during authentication: type %d", type);
                        break;
                }
-               if (authenticated && pw == NULL)
-                       fatal("internal error: authenticated for pw == NULL");
+#ifdef BSD_AUTH
+               if (authctxt->as) {
+                       auth_close(authctxt->as);
+                       authctxt->as = NULL;
+               }
+#endif
+               if (!authctxt->valid && authenticated)
+                       fatal("INTERNAL ERROR: authenticated invalid user %s",
+                           authctxt->user);
 
 #ifdef HAVE_CYGWIN
-               if (authenticated && 
+               if (authenticated &&
                    !check_nt_auth(type == SSH_CMSG_AUTH_PASSWORD,pw->pw_uid)) {
                        packet_disconnect("Authentication rejected for uid %d.",
                        (int)pw->pw_uid);
                        authenticated = 0;
                }
+#else
+               /* Special handling for root */
+               if (authenticated && authctxt->pw->pw_uid == 0 &&
+                   !auth_root_allowed(get_authname(type)))
+                       authenticated = 0;
 #endif
-
-               /*
-                * Check if the user is logging in as root and root logins
-                * are disallowed.
-                * Note that root login is allowed for forced commands.
-                */
-               if (authenticated && pw && pw->pw_uid == 0 && !options.permit_root_login) {
-                       if (forced_command) {
-                               log("Root login accepted for forced command.");
-                       } else {
-                               authenticated = 0;
-                               log("ROOT LOGIN REFUSED FROM %.200s",
-                                   get_canonical_hostname());
-                       }
-               }
-
-               /* Raise logging level */
-               if (authenticated ||
-                   attempt == AUTH_FAIL_LOG ||
-                   type == SSH_CMSG_AUTH_PASSWORD)
-                       authlog = log;
-
-               authlog("%s %s for %s%.100s from %.200s port %d%s",
-                       authenticated ? "Accepted" : "Failed",
-                       get_authname(type),
-                       pw ? "" : "illegal user ",
-                       pw && pw->pw_uid == 0 ? "ROOT" : luser,
-                       get_remote_ipaddr(),
-                       get_remote_port(),
-                       user);
-
 #ifdef USE_PAM
                if (authenticated && !do_pam_account(pw->pw_name, client_user))
                        authenticated = 0;
 #endif
 
+               /* Log before sending the reply */
+               auth_log(authctxt, authenticated, get_authname(type), info);
+
                if (client_user != NULL) {
                        xfree(client_user);
                        client_user = NULL;
@@ -371,14 +342,15 @@ do_authloop(struct passwd * pw, char *luser)
                if (authenticated)
                        return;
 
-               if (attempt > AUTH_FAIL_MAX) {
-#ifdef WITH_AIXAUTHENTICATE 
-                       loginfailed(user,get_canonical_hostname(),"ssh");
+               if (authctxt->failures++ > AUTH_FAIL_MAX) {
+#ifdef WITH_AIXAUTHENTICATE
+                       loginfailed(authctxt->user,
+                           get_canonical_hostname(options.reverse_mapping_check),
+                           "ssh");
 #endif /* WITH_AIXAUTHENTICATE */
-                       packet_disconnect(AUTH_FAIL_MSG, luser);
+                       packet_disconnect(AUTH_FAIL_MSG, authctxt->user);
                }
 
-               /* Send a message indicating that the authentication attempt failed. */
                packet_start(SSH_SMSG_FAILURE);
                packet_send();
                packet_write_wait();
@@ -392,10 +364,11 @@ do_authloop(struct passwd * pw, char *luser)
 void
 do_authentication()
 {
-       struct passwd *pw, pwcopy;
+       Authctxt *authctxt;
+       struct passwd *pw;
        int plen;
        u_int ulen;
-       char *user;
+       char *user, *style = NULL;
 
        /* Get the name of the user that we wish to log in as. */
        packet_read_expect(&plen, SSH_CMSG_USER);
@@ -404,38 +377,29 @@ do_authentication()
        user = packet_get_string(&ulen);
        packet_integrity_check(plen, (4 + ulen), SSH_CMSG_USER);
 
-       setproctitle("%s", user);
+       if ((style = strchr(user, ':')) != NULL)
+               *style++ = 0;
 
-#ifdef AFS
-       /* If machine has AFS, set process authentication group. */
-       if (k_hasafs()) {
-               k_setpag();
-               k_unlog();
-       }
-#endif /* AFS */
+       authctxt = authctxt_new();
+       authctxt->user = user;
+       authctxt->style = style;
 
        /* Verify that the user is a valid user. */
        pw = getpwnam(user);
        if (pw && allowed_user(pw)) {
-               /* Take a copy of the returned structure. */
-               memset(&pwcopy, 0, sizeof(pwcopy));
-               pwcopy.pw_name = xstrdup(pw->pw_name);
-               pwcopy.pw_passwd = xstrdup(pw->pw_passwd);
-               pwcopy.pw_uid = pw->pw_uid;
-               pwcopy.pw_gid = pw->pw_gid;
-#ifdef HAVE_PW_CLASS_IN_PASSWD
-               pwcopy.pw_class = xstrdup(pw->pw_class);
-#endif
-               pwcopy.pw_dir = xstrdup(pw->pw_dir);
-               pwcopy.pw_shell = xstrdup(pw->pw_shell);
-               pw = &pwcopy;
+               authctxt->valid = 1;
+               pw = pwcopy(pw);
        } else {
+               debug("do_authentication: illegal user %s", user);
                pw = NULL;
        }
+       authctxt->pw = pw;
+
+       setproctitle("%s", pw ? user : "unknown");
 
 #ifdef USE_PAM
        if (pw)
-               start_pam(pw);
+               start_pam(user);
 #endif
 
        /*
@@ -447,46 +411,28 @@ do_authentication()
                packet_disconnect("Cannot change user when server not running as root.");
 #endif
 
-       debug("Attempting authentication for %s%.100s.", pw ? "" : "illegal user ", user);
-
-       /* If the user has no password, accept authentication immediately. */
-       if (options.password_authentication &&
-#ifdef KRB4
-           (!options.kerberos_authentication || options.kerberos_or_local_passwd) &&
-#endif /* KRB4 */
-#ifdef USE_PAM
-           auth_pam_password(pw, "")) {
-#elif defined(HAVE_OSF_SIA)
-           (sia_validate_user(NULL, saved_argc, saved_argv, 
-           get_canonical_hostname(), pw->pw_name, NULL, 0, 
-                NULL, "") == SIASUCCESS)) {
-#else /* !HAVE_OSF_SIA && !USE_PAM */
-           auth_password(pw, "")) {
-#endif /* USE_PAM */
-               /* Authentication with empty password succeeded. */
-               log("Login for user %s from %.100s, accepted without authentication.",
-                   user, get_remote_ipaddr());
-       } else {
-               /* Loop until the user has been authenticated or the
-                  connection is closed, do_authloop() returns only if
-                  authentication is successful */
-               do_authloop(pw, user);
-       }
-       if (pw == NULL)
-               fatal("internal error, authentication successful for user '%.100s'", user);
+       /*
+        * Loop until the user has been authenticated or the connection is
+        * closed, do_authloop() returns only if authentication is successful
+        */
+       do_authloop(authctxt);
 
        /* The user has been authenticated and accepted. */
        packet_start(SSH_SMSG_SUCCESS);
        packet_send();
        packet_write_wait();
-       xfree(user);
 
 #ifdef WITH_AIXAUTHENTICATE
        /* We don't have a pty yet, so just label the line as "ssh" */
-       if (loginsuccess(user,get_canonical_hostname(),"ssh",&aixloginmsg) < 0)
+       if (loginsuccess(authctxt->user,
+           get_canonical_hostname(options.reverse_mapping_check),
+           "ssh", &aixloginmsg) < 0)
                aixloginmsg = NULL;
 #endif /* WITH_AIXAUTHENTICATE */
 
+       xfree(authctxt->user);
+       xfree(authctxt);
+
        /* Perform session preparation. */
        do_authenticated(pw);
 }
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