*/
#include "includes.h"
-RCSID("$OpenBSD: auth2.c,v 1.21 2000/11/12 19:50:37 markus Exp $");
+RCSID("$OpenBSD: auth2.c,v 1.57 2001/05/18 14:13:28 markus Exp $");
-#ifdef HAVE_OSF_SIA
-# include <sia.h>
-# include <siad.h>
-#endif
-
-#include <openssl/dsa.h>
-#include <openssl/rsa.h>
#include <openssl/evp.h>
+#include "ssh2.h"
#include "xmalloc.h"
#include "rsa.h"
-#include "ssh.h"
-#include "pty.h"
+#include "sshpty.h"
#include "packet.h"
#include "buffer.h"
+#include "log.h"
#include "servconf.h"
#include "compat.h"
#include "channels.h"
#include "bufaux.h"
-#include "ssh2.h"
#include "auth.h"
#include "session.h"
#include "dispatch.h"
-#include "auth.h"
#include "key.h"
+#include "cipher.h"
#include "kex.h"
-
+#include "pathnames.h"
#include "uidswap.h"
#include "auth-options.h"
+#include "misc.h"
+#include "hostfile.h"
+#include "canohost.h"
+#include "tildexpand.h"
+#include "match.h"
/* import */
extern ServerOptions options;
-extern unsigned char *session_id2;
+extern u_char *session_id2;
extern int session_id2_len;
#ifdef WITH_AIXAUTHENTICATE
extern char *aixloginmsg;
#endif
-#ifdef HAVE_OSF_SIA
-extern int saved_argc;
-extern char **saved_argv;
-#endif
static Authctxt *x_authctxt = NULL;
static int one = 1;
void input_userauth_request(int type, int plen, void *ctxt);
void protocol_error(int type, int plen, void *ctxt);
-
/* helper */
Authmethod *authmethod_lookup(const char *name);
-struct passwd *pwcopy(struct passwd *pw);
-int user_key_allowed(struct passwd *pw, Key *key);
char *authmethods_get(void);
+int user_key_allowed(struct passwd *pw, Key *key);
+int
+hostbased_key_allowed(struct passwd *pw, const char *cuser, char *chost,
+ Key *key);
/* auth */
+void userauth_banner(void);
+void userauth_reply(Authctxt *authctxt, int authenticated);
int userauth_none(Authctxt *authctxt);
int userauth_passwd(Authctxt *authctxt);
int userauth_pubkey(Authctxt *authctxt);
+int userauth_hostbased(Authctxt *authctxt);
int userauth_kbdint(Authctxt *authctxt);
Authmethod authmethods[] = {
{"publickey",
userauth_pubkey,
&options.pubkey_authentication},
- {"keyboard-interactive",
- userauth_kbdint,
- &options.kbd_interactive_authentication},
{"password",
userauth_passwd,
&options.password_authentication},
+ {"keyboard-interactive",
+ userauth_kbdint,
+ &options.kbd_interactive_authentication},
+ {"hostbased",
+ userauth_hostbased,
+ &options.hostbased_authentication},
{NULL, NULL, NULL}
};
void
do_authentication2()
{
- Authctxt *authctxt = xmalloc(sizeof(*authctxt));
- memset(authctxt, 'a', sizeof(*authctxt));
- authctxt->valid = 0;
- authctxt->attempt = 0;
- authctxt->success = 0;
+ Authctxt *authctxt = authctxt_new();
+
x_authctxt = authctxt; /*XXX*/
-#ifdef KRB4
- /* turn off kerberos, not supported by SSH2 */
- options.kerberos_authentication = 0;
-#endif
+ /* challenge-reponse is implemented via keyboard interactive */
+ if (options.challenge_response_authentication)
+ options.kbd_interactive_authentication = 1;
+ if (options.pam_authentication_via_kbd_int)
+ options.kbd_interactive_authentication = 1;
+
dispatch_init(&protocol_error);
dispatch_set(SSH2_MSG_SERVICE_REQUEST, &input_service_request);
dispatch_run(DISPATCH_BLOCK, &authctxt->success, authctxt);
- do_authenticated2();
+ do_authenticated(authctxt);
}
void
input_service_request(int type, int plen, void *ctxt)
{
Authctxt *authctxt = ctxt;
- unsigned int len;
+ u_int len;
int accept = 0;
char *service = packet_get_string(&len);
packet_done();
{
Authctxt *authctxt = ctxt;
Authmethod *m = NULL;
- char *user, *service, *method;
+ char *user, *service, *method, *style = NULL;
int authenticated = 0;
if (authctxt == NULL)
fatal("input_userauth_request: no authctxt");
- if (authctxt->attempt++ >= AUTH_FAIL_MAX) {
-#ifdef WITH_AIXAUTHENTICATE
- loginfailed(authctxt->user?authctxt->user:"NOUSER",
- get_canonical_hostname(), "ssh");
-#endif /* WITH_AIXAUTHENTICATE */
- packet_disconnect("too many failed userauth_requests");
- }
user = packet_get_string(NULL);
service = packet_get_string(NULL);
method = packet_get_string(NULL);
debug("userauth-request for user %s service %s method %s", user, service, method);
- debug("attempt #%d", authctxt->attempt);
+ debug("attempt %d failures %d", authctxt->attempt, authctxt->failures);
+
+ if ((style = strchr(user, ':')) != NULL)
+ *style++ = 0;
- if (authctxt->attempt == 1) {
+ if (authctxt->attempt++ == 0) {
/* setup auth context */
struct passwd *pw = NULL;
- setproctitle("%s", user);
pw = getpwnam(user);
if (pw && allowed_user(pw) && strcmp(service, "ssh-connection")==0) {
authctxt->pw = pwcopy(pw);
authctxt->valid = 1;
debug2("input_userauth_request: setting up authctxt for %s", user);
#ifdef USE_PAM
- start_pam(pw);
+ start_pam(pw->pw_name);
#endif
} else {
log("input_userauth_request: illegal user %s", user);
+#ifdef USE_PAM
+ start_pam("NOUSER");
+#endif
}
+ setproctitle("%s", pw ? user : "unknown");
authctxt->user = xstrdup(user);
authctxt->service = xstrdup(service);
+ authctxt->style = style ? xstrdup(style) : NULL; /* currently unused */
} else if (authctxt->valid) {
if (strcmp(user, authctxt->user) != 0 ||
strcmp(service, authctxt->service) != 0) {
- log("input_userauth_request: missmatch: (%s,%s)!=(%s,%s)",
+ log("input_userauth_request: mismatch: (%s,%s)!=(%s,%s)",
user, service, authctxt->user, authctxt->service);
authctxt->valid = 0;
}
}
+ /* reset state */
+ dispatch_set(SSH2_MSG_USERAUTH_INFO_RESPONSE, &protocol_error);
+ authctxt->postponed = 0;
+#ifdef BSD_AUTH
+ if (authctxt->as) {
+ auth_close(authctxt->as);
+ authctxt->as = NULL;
+ }
+#endif
+ /* try to authenticate user */
m = authmethod_lookup(method);
if (m != NULL) {
debug2("input_userauth_request: try method %s", method);
authenticated = m->userauth(authctxt);
- } else {
- debug2("input_userauth_request: unsupported method %s", method);
- }
- if (!authctxt->valid && authenticated == 1) {
- log("input_userauth_request: INTERNAL ERROR: authenticated invalid user %s service %s", user, method);
- authenticated = 0;
}
+ userauth_finish(authctxt, authenticated, method);
+
+ xfree(service);
+ xfree(user);
+ xfree(method);
+}
+
+void
+userauth_finish(Authctxt *authctxt, int authenticated, char *method)
+{
+ if (!authctxt->valid && authenticated)
+ fatal("INTERNAL ERROR: authenticated invalid user %s",
+ authctxt->user);
/* Special handling for root */
- if (authenticated == 1 &&
- authctxt->valid && authctxt->pw->pw_uid == 0 && !options.permit_root_login) {
+ if (authenticated && authctxt->pw->pw_uid == 0 &&
+ !auth_root_allowed(method))
authenticated = 0;
- log("ROOT LOGIN REFUSED FROM %.200s", get_canonical_hostname());
- }
#ifdef USE_PAM
- if (authenticated && authctxt->user && !do_pam_account(authctxt->user, NULL))
+ if (authenticated && authctxt->user && !do_pam_account(authctxt->user,
+ NULL))
authenticated = 0;
#endif /* USE_PAM */
/* Log before sending the reply */
- userauth_log(authctxt, authenticated, method);
- userauth_reply(authctxt, authenticated);
+ auth_log(authctxt, authenticated, method, " ssh2");
- xfree(service);
- xfree(user);
- xfree(method);
+ if (!authctxt->postponed)
+ userauth_reply(authctxt, authenticated);
}
-
void
-userauth_log(Authctxt *authctxt, int authenticated, char *method)
+userauth_banner(void)
{
- void (*authlog) (const char *fmt,...) = verbose;
- char *user = NULL, *authmsg = NULL;
-
- /* Raise logging level */
- if (authenticated == 1 ||
- !authctxt->valid ||
- authctxt->attempt >= AUTH_FAIL_LOG ||
- strcmp(method, "password") == 0)
- authlog = log;
-
- if (authenticated == 1) {
- authmsg = "Accepted";
- } else if (authenticated == 0) {
- authmsg = "Failed";
- } else {
- authmsg = "Postponed";
- }
-
- if (authctxt->valid) {
- user = authctxt->pw->pw_uid == 0 ? "ROOT" : authctxt->user;
- } else {
- user = "NOUSER";
- }
-
- authlog("%s %s for %.200s from %.200s port %d ssh2",
- authmsg,
- method,
- user,
- get_remote_ipaddr(),
- get_remote_port());
+ struct stat st;
+ char *banner = NULL;
+ off_t len, n;
+ int fd;
+
+ if (options.banner == NULL || (datafellows & SSH_BUG_BANNER))
+ return;
+ if ((fd = open(options.banner, O_RDONLY)) < 0)
+ return;
+ if (fstat(fd, &st) < 0)
+ goto done;
+ len = st.st_size;
+ banner = xmalloc(len + 1);
+ if ((n = read(fd, banner, len)) < 0)
+ goto done;
+ banner[n] = '\0';
+ packet_start(SSH2_MSG_USERAUTH_BANNER);
+ packet_put_cstring(banner);
+ packet_put_cstring(""); /* language, unused */
+ packet_send();
+ debug("userauth_banner: sent");
+done:
+ if (banner)
+ xfree(banner);
+ close(fd);
+ return;
}
-void
+void
userauth_reply(Authctxt *authctxt, int authenticated)
{
+ char *methods;
+
/* XXX todo: check if multiple auth methods are needed */
if (authenticated == 1) {
#ifdef WITH_AIXAUTHENTICATE
/* We don't have a pty yet, so just label the line as "ssh" */
- if (loginsuccess(authctxt->user?authctxt->user:"NOUSER",
- get_canonical_hostname(), "ssh", &aixloginmsg) < 0)
+ if (loginsuccess(authctxt->user?authctxt->user:"NOUSER",
+ get_canonical_hostname(options.reverse_mapping_check),
+ "ssh", &aixloginmsg) < 0)
aixloginmsg = NULL;
#endif /* WITH_AIXAUTHENTICATE */
/* turn off userauth */
packet_write_wait();
/* now we can break out */
authctxt->success = 1;
- } else if (authenticated == 0) {
- char *methods = authmethods_get();
+ } else {
+ if (authctxt->failures++ > AUTH_FAIL_MAX)
+ packet_disconnect(AUTH_FAIL_MSG, authctxt->user);
+ methods = authmethods_get();
packet_start(SSH2_MSG_USERAUTH_FAILURE);
packet_put_cstring(methods);
packet_put_char(0); /* XXX partial success, unused */
packet_send();
packet_write_wait();
xfree(methods);
- } else {
- /* do nothing, we did already send a reply */
}
}
if (m != NULL)
m->enabled = NULL;
packet_done();
+ userauth_banner();
if (authctxt->valid == 0)
return(0);
-
+
#ifdef HAVE_CYGWIN
if (check_nt_auth(1, authctxt->pw->pw_uid) == 0)
return(0);
#ifdef USE_PAM
return auth_pam_password(authctxt->pw, "");
#elif defined(HAVE_OSF_SIA)
- return (sia_validate_user(NULL, saved_argc, saved_argv,
- get_canonical_hostname(), authctxt->user?authctxt->user:"NOUSER",
- NULL, 0, NULL, "") == SIASUCCESS);
+ return 0;
#else /* !HAVE_OSF_SIA && !USE_PAM */
- return auth_password(authctxt->pw, "");
+ return auth_password(authctxt, "");
#endif /* USE_PAM */
}
char *password;
int authenticated = 0;
int change;
- unsigned int len;
+ u_int len;
change = packet_get_char();
if (change)
log("password change not supported");
#ifdef USE_PAM
auth_pam_password(authctxt->pw, password) == 1)
#elif defined(HAVE_OSF_SIA)
- sia_validate_user(NULL, saved_argc, saved_argv,
- get_canonical_hostname(), authctxt->user?authctxt->user:"NOUSER",
- NULL, 0, NULL, password) == SIASUCCESS)
+ auth_sia_password(authctxt->user, password) == 1)
#else /* !USE_PAM && !HAVE_OSF_SIA */
- auth_password(authctxt->pw, password) == 1)
+ auth_password(authctxt, password) == 1)
#endif /* USE_PAM */
authenticated = 1;
memset(password, 0, len);
userauth_kbdint(Authctxt *authctxt)
{
int authenticated = 0;
- char *lang = NULL;
- char *devs = NULL;
+ char *lang, *devs;
lang = packet_get_string(NULL);
devs = packet_get_string(NULL);
packet_done();
- debug("keyboard-interactive language %s devs %s", lang, devs);
+ debug("keyboard-interactive devs %s", devs);
+
+ if (options.challenge_response_authentication)
+ authenticated = auth2_challenge(authctxt, devs);
+
#ifdef USE_PAM
- if (authenticated == 0)
+ if (authenticated == 0 && options.pam_authentication_via_kbd_int)
authenticated = auth2_pam(authctxt);
#endif
-#ifdef SKEY
- /* XXX hardcoded, we should look at devs */
- if (authenticated == 0)
- if (options.skey_authentication != 0)
- authenticated = auth2_skey(authctxt);
-#endif
- xfree(lang);
xfree(devs);
+ xfree(lang);
#ifdef HAVE_CYGWIN
if (check_nt_auth(0, authctxt->pw->pw_uid) == 0)
return(0);
Buffer b;
Key *key;
char *pkalg, *pkblob, *sig;
- unsigned int alen, blen, slen;
+ u_int alen, blen, slen;
int have_sig, pktype;
int authenticated = 0;
return 0;
}
have_sig = packet_get_char();
- pkalg = packet_get_string(&alen);
+ if (datafellows & SSH_BUG_PKAUTH) {
+ debug2("userauth_pubkey: SSH_BUG_PKAUTH");
+ /* no explicit pkalg given */
+ pkblob = packet_get_string(&blen);
+ buffer_init(&b);
+ buffer_append(&b, pkblob, blen);
+ /* so we have to extract the pkalg from the pkblob */
+ pkalg = buffer_get_string(&b, &alen);
+ buffer_free(&b);
+ } else {
+ pkalg = packet_get_string(&alen);
+ pkblob = packet_get_string(&blen);
+ }
pktype = key_type_from_name(pkalg);
if (pktype == KEY_UNSPEC) {
- log("bad pkalg %s", pkalg);
+ /* this is perfectly legal */
+ log("userauth_pubkey: unsupported public key algorithm: %s", pkalg);
xfree(pkalg);
+ xfree(pkblob);
return 0;
}
- pkblob = packet_get_string(&blen);
key = key_from_blob(pkblob, blen);
if (key != NULL) {
if (have_sig) {
buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
buffer_put_cstring(&b, authctxt->user);
buffer_put_cstring(&b,
- datafellows & SSH_BUG_PUBKEYAUTH ?
+ datafellows & SSH_BUG_PKSERVICE ?
"ssh-userauth" :
authctxt->service);
- buffer_put_cstring(&b, "publickey");
- buffer_put_char(&b, have_sig);
- buffer_put_cstring(&b, key_ssh_name(key));
+ if (datafellows & SSH_BUG_PKAUTH) {
+ buffer_put_char(&b, have_sig);
+ } else {
+ buffer_put_cstring(&b, "publickey");
+ buffer_put_char(&b, have_sig);
+ buffer_put_cstring(&b, pkalg);
+ }
buffer_put_string(&b, pkblob, blen);
#ifdef DEBUG_PK
buffer_dump(&b);
packet_put_string(pkblob, blen);
packet_send();
packet_write_wait();
- authenticated = -1;
+ authctxt->postponed = 1;
}
}
if (authenticated != 1)
return authenticated;
}
+int
+userauth_hostbased(Authctxt *authctxt)
+{
+ Buffer b;
+ Key *key;
+ char *pkalg, *pkblob, *sig, *cuser, *chost, *service;
+ u_int alen, blen, slen;
+ int pktype;
+ int authenticated = 0;
+
+ if (!authctxt->valid) {
+ debug2("userauth_hostbased: disabled because of invalid user");
+ return 0;
+ }
+ pkalg = packet_get_string(&alen);
+ pkblob = packet_get_string(&blen);
+ chost = packet_get_string(NULL);
+ cuser = packet_get_string(NULL);
+ sig = packet_get_string(&slen);
+
+ debug("userauth_hostbased: cuser %s chost %s pkalg %s slen %d",
+ cuser, chost, pkalg, slen);
+#ifdef DEBUG_PK
+ debug("signature:");
+ buffer_init(&b);
+ buffer_append(&b, sig, slen);
+ buffer_dump(&b);
+ buffer_free(&b);
+#endif
+ pktype = key_type_from_name(pkalg);
+ if (pktype == KEY_UNSPEC) {
+ /* this is perfectly legal */
+ log("userauth_hostbased: unsupported "
+ "public key algorithm: %s", pkalg);
+ goto done;
+ }
+ key = key_from_blob(pkblob, blen);
+ if (key == NULL) {
+ debug("userauth_hostbased: cannot decode key: %s", pkalg);
+ goto done;
+ }
+ service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
+ authctxt->service;
+ buffer_init(&b);
+ buffer_put_string(&b, session_id2, session_id2_len);
+ /* reconstruct packet */
+ buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
+ buffer_put_cstring(&b, authctxt->user);
+ buffer_put_cstring(&b, service);
+ buffer_put_cstring(&b, "hostbased");
+ buffer_put_string(&b, pkalg, alen);
+ buffer_put_string(&b, pkblob, blen);
+ buffer_put_cstring(&b, chost);
+ buffer_put_cstring(&b, cuser);
+#ifdef DEBUG_PK
+ buffer_dump(&b);
+#endif
+ /* test for allowed key and correct signature */
+ if (hostbased_key_allowed(authctxt->pw, cuser, chost, key) &&
+ key_verify(key, sig, slen, buffer_ptr(&b), buffer_len(&b)) == 1)
+ authenticated = 1;
+
+ buffer_clear(&b);
+ key_free(key);
+
+done:
+ debug2("userauth_hostbased: authenticated %d", authenticated);
+ xfree(pkalg);
+ xfree(pkblob);
+ xfree(cuser);
+ xfree(chost);
+ xfree(sig);
+ return authenticated;
+}
+
/* get current user */
struct passwd*
authmethods_get(void)
{
Authmethod *method = NULL;
- unsigned int size = 0;
+ u_int size = 0;
char *list;
for (method = authmethods; method->name != NULL; method++) {
int
user_key_allowed(struct passwd *pw, Key *key)
{
- char line[8192], file[1024];
+ char line[8192], file[MAXPATHLEN];
int found_key = 0;
FILE *f;
- unsigned long linenum = 0;
+ u_long linenum = 0;
struct stat st;
Key *found;
return 0;
/* Temporarily use the user's uid. */
- temporarily_use_uid(pw->pw_uid);
+ temporarily_use_uid(pw);
/* The authorized keys. */
snprintf(file, sizeof file, "%.500s/%.100s", pw->pw_dir,
- SSH_USER_PERMITTED_KEYS2);
+ _PATH_SSH_USER_PERMITTED_KEYS2);
/* Fail quietly if file does not exist */
if (stat(file, &st) < 0) {
key_type(key), pw->pw_name, file);
fail = 1;
} else {
- /* Check path to SSH_USER_PERMITTED_KEYS */
+ /* Check path to _PATH_SSH_USER_PERMITTED_KEYS */
int i;
static const char *check[] = {
- "", SSH_USER_DIR, NULL
+ "", _PATH_SSH_USER_DIR, NULL
};
for (i = 0; check[i]; i++) {
snprintf(line, sizeof line, "%.500s/%.100s",
}
if (fail) {
fclose(f);
- log("%s",buf);
+ log("%s", buf);
restore_uid();
return 0;
}
}
}
if (key_equal(found, key) &&
- auth_parse_options(pw, options, linenum) == 1) {
+ auth_parse_options(pw, options, file, linenum) == 1) {
found_key = 1;
debug("matching key found: file %s, line %ld",
file, linenum);
restore_uid();
fclose(f);
key_free(found);
+ if (!found_key)
+ debug2("key not found");
return found_key;
}
-struct passwd *
-pwcopy(struct passwd *pw)
+/* return 1 if given hostkey is allowed */
+int
+hostbased_key_allowed(struct passwd *pw, const char *cuser, char *chost,
+ Key *key)
{
- struct passwd *copy = xmalloc(sizeof(*copy));
- memset(copy, 0, sizeof(*copy));
- copy->pw_name = xstrdup(pw->pw_name);
- copy->pw_passwd = xstrdup(pw->pw_passwd);
- copy->pw_uid = pw->pw_uid;
- copy->pw_gid = pw->pw_gid;
-#ifdef HAVE_PW_CLASS_IN_PASSWD
- copy->pw_class = xstrdup(pw->pw_class);
-#endif
- copy->pw_dir = xstrdup(pw->pw_dir);
- copy->pw_shell = xstrdup(pw->pw_shell);
- return copy;
+ Key *found;
+ const char *resolvedname, *ipaddr, *lookup;
+ struct stat st;
+ char *user_hostfile;
+ int host_status, len;
+
+ resolvedname = get_canonical_hostname(options.reverse_mapping_check);
+ ipaddr = get_remote_ipaddr();
+
+ debug2("userauth_hostbased: chost %s resolvedname %s ipaddr %s",
+ chost, resolvedname, ipaddr);
+
+ if (options.hostbased_uses_name_from_packet_only) {
+ if (auth_rhosts2(pw, cuser, chost, chost) == 0)
+ return 0;
+ lookup = chost;
+ } else {
+ if (((len = strlen(chost)) > 0) && chost[len - 1] == '.') {
+ debug2("stripping trailing dot from chost %s", chost);
+ chost[len - 1] = '\0';
+ }
+ if (strcasecmp(resolvedname, chost) != 0)
+ log("userauth_hostbased mismatch: "
+ "client sends %s, but we resolve %s to %s",
+ chost, ipaddr, resolvedname);
+ if (auth_rhosts2(pw, cuser, resolvedname, ipaddr) == 0)
+ return 0;
+ lookup = resolvedname;
+ }
+ debug2("userauth_hostbased: access allowed by auth_rhosts2");
+
+ /* XXX this is copied from auth-rh-rsa.c and should be shared */
+ found = key_new(key->type);
+ host_status = check_host_in_hostfile(_PATH_SSH_SYSTEM_HOSTFILE2, lookup,
+ key, found, NULL);
+
+ if (host_status != HOST_OK && !options.ignore_user_known_hosts) {
+ user_hostfile = tilde_expand_filename(_PATH_SSH_USER_HOSTFILE2,
+ pw->pw_uid);
+ if (options.strict_modes &&
+ (stat(user_hostfile, &st) == 0) &&
+ ((st.st_uid != 0 && st.st_uid != pw->pw_uid) ||
+ (st.st_mode & 022) != 0)) {
+ log("Hostbased authentication refused for %.100s: "
+ "bad owner or modes for %.200s",
+ pw->pw_name, user_hostfile);
+ } else {
+ temporarily_use_uid(pw);
+ host_status = check_host_in_hostfile(user_hostfile,
+ lookup, key, found, NULL);
+ restore_uid();
+ }
+ xfree(user_hostfile);
+ }
+ key_free(found);
+
+ debug2("userauth_hostbased: key %s for %s", host_status == HOST_OK ?
+ "ok" : "not found", lookup);
+ return (host_status == HOST_OK);
}
andersk / openssh.git / blobdiff