*/
#include "includes.h"
-RCSID("$OpenBSD: auth1.c,v 1.11 2001/01/18 16:59:59 markus Exp $");
-
-#ifdef HAVE_OSF_SIA
-# include <sia.h>
-# include <siad.h>
-#endif
+RCSID("$OpenBSD: auth1.c,v 1.41 2002/06/19 00:27:55 deraadt 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"
+#include "channels.h"
#include "session.h"
+#include "uidswap.h"
+#include "monitor_wrap.h"
/* import */
extern ServerOptions options;
-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
*/
-char *
+static char *
get_authname(int type)
{
static char buf[1024];
case SSH_CMSG_AUTH_TIS:
case SSH_CMSG_AUTH_TIS_RESPONSE:
return "challenge-response";
-#ifdef KRB4
+#if defined(KRB4) || defined(KRB5)
case SSH_CMSG_AUTH_KERBEROS:
return "kerberos";
#endif
* read packets, try to authenticate the user and
* return only if authentication is successful
*/
-void
+static void
do_authloop(Authctxt *authctxt)
{
int authenticated = 0;
u_int bits;
- RSA *client_host_key;
+ Key *client_host_key;
BIGNUM *n;
char *client_user, *password;
char info[1024];
u_int dlen;
- int plen, nlen, elen;
u_int ulen;
int type = 0;
struct passwd *pw = authctxt->pw;
debug("Attempting authentication for %s%.100s.",
- authctxt->valid ? "" : "illegal user ", authctxt->user);
+ authctxt->valid ? "" : "illegal user ", authctxt->user);
/* If the user has no password, accept authentication immediately. */
if (options.password_authentication &&
-#ifdef KRB4
+#if defined(KRB4) || defined(KRB5)
(!options.kerberos_authentication || options.kerberos_or_local_passwd) &&
#endif
-#ifdef USE_PAM /* ISSUE: Right?? */
- auth_pam_password(pw, password)) {
-#else
- auth_password(pw, "")) {
-#endif
+ PRIVSEP(auth_password(authctxt, ""))) {
auth_log(authctxt, 1, "without authentication", "");
return;
}
info[0] = '\0';
/* Get a packet from the client. */
- type = packet_read(&plen);
+ type = packet_read();
/* Process the packet. */
switch (type) {
-#ifdef AFS
- case SSH_CMSG_HAVE_KERBEROS_TGT:
- if (!options.kerberos_tgt_passing) {
- verbose("Kerberos tgt passing disabled.");
- break;
- } else {
- /* Accept Kerberos tgt. */
- 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", authctxt->user);
- xfree(tgt);
- }
- continue;
- case SSH_CMSG_HAVE_AFS_TOKEN:
- if (!options.afs_token_passing || !k_hasafs()) {
- verbose("AFS token passing disabled.");
- break;
- } else {
- /* Accept AFS token. */
- 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", authctxt->user);
- xfree(token_string);
- }
- continue;
-#endif /* AFS */
-#ifdef KRB4
+#if defined(KRB4) || defined(KRB5)
case SSH_CMSG_AUTH_KERBEROS:
if (!options.kerberos_authentication) {
verbose("Kerberos authentication disabled.");
- break;
} else {
- /* Try Kerberos v4 authentication. */
- KTEXT_ST auth;
- char *tkt_user = NULL;
- char *kdata = packet_get_string((u_int *) &auth.length);
- packet_integrity_check(plen, 4 + auth.length, type);
-
- 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(info, sizeof info,
- " tktuser %.100s", tkt_user);
- xfree(tkt_user);
+ char *kdata = packet_get_string(&dlen);
+ packet_check_eom();
+
+ if (kdata[0] == 4) { /* KRB_PROT_VERSION */
+#ifdef KRB4
+ KTEXT_ST tkt;
+
+ tkt.length = dlen;
+ if (tkt.length < MAX_KTXT_LEN)
+ memcpy(tkt.dat, kdata, tkt.length);
+
+ if (auth_krb4(authctxt, &tkt, &client_user)) {
+ authenticated = 1;
+ snprintf(info, sizeof(info),
+ " tktuser %.100s",
+ client_user);
+ }
+#endif /* KRB4 */
+ } else {
+#ifdef KRB5
+ krb5_data tkt;
+ tkt.length = dlen;
+ tkt.data = kdata;
+
+ if (auth_krb5(authctxt, &tkt, &client_user)) {
+ authenticated = 1;
+ snprintf(info, sizeof(info),
+ " tktuser %.100s",
+ client_user);
}
+#endif /* KRB5 */
}
xfree(kdata);
}
break;
-#endif /* KRB4 */
+#endif /* KRB4 || KRB5 */
+
+#if defined(AFS) || defined(KRB5)
+ /* XXX - punt on backward compatibility here. */
+ case SSH_CMSG_HAVE_KERBEROS_TGT:
+ packet_send_debug("Kerberos TGT passing disabled before authentication.");
+ break;
+#ifdef AFS
+ case SSH_CMSG_HAVE_AFS_TOKEN:
+ packet_send_debug("AFS token passing disabled before authentication.");
+ break;
+#endif /* AFS */
+#endif /* AFS || KRB5 */
case SSH_CMSG_AUTH_RHOSTS:
if (!options.rhosts_authentication) {
* IP-spoofing on a local network.)
*/
client_user = packet_get_string(&ulen);
- packet_integrity_check(plen, 4 + ulen, type);
+ packet_check_eom();
/* Try to authenticate using /etc/hosts.equiv and .rhosts. */
authenticated = auth_rhosts(pw, client_user);
client_user = packet_get_string(&ulen);
/* Get the client host key. */
- client_host_key = RSA_new();
- if (client_host_key == NULL)
- fatal("RSA_new failed");
- client_host_key->e = BN_new();
- client_host_key->n = BN_new();
- if (client_host_key->e == NULL || client_host_key->n == NULL)
- fatal("BN_new failed");
+ client_host_key = key_new(KEY_RSA1);
bits = packet_get_int();
- packet_get_bignum(client_host_key->e, &elen);
- packet_get_bignum(client_host_key->n, &nlen);
+ packet_get_bignum(client_host_key->rsa->e);
+ packet_get_bignum(client_host_key->rsa->n);
- if (bits != BN_num_bits(client_host_key->n))
+ if (bits != BN_num_bits(client_host_key->rsa->n))
verbose("Warning: keysize mismatch for client_host_key: "
- "actual %d, announced %d", BN_num_bits(client_host_key->n), bits);
- packet_integrity_check(plen, (4 + ulen) + 4 + elen + nlen, type);
+ "actual %d, announced %d",
+ BN_num_bits(client_host_key->rsa->n), bits);
+ packet_check_eom();
- authenticated = auth_rhosts_rsa(pw, client_user, client_host_key);
- RSA_free(client_host_key);
+ authenticated = auth_rhosts_rsa(pw, client_user,
+ client_host_key);
+ key_free(client_host_key);
snprintf(info, sizeof info, " ruser %.100s", client_user);
break;
break;
}
/* RSA authentication requested. */
- n = BN_new();
- packet_get_bignum(n, &nlen);
- packet_integrity_check(plen, nlen, type);
+ if ((n = BN_new()) == NULL)
+ fatal("do_authloop: BN_new failed");
+ packet_get_bignum(n);
+ packet_check_eom();
authenticated = auth_rsa(pw, n);
BN_clear_free(n);
break;
* not visible to an outside observer.
*/
password = packet_get_string(&dlen);
- packet_integrity_check(plen, 4 + dlen, type);
+ packet_check_eom();
-#ifdef USE_PAM
- /* Do PAM auth with password */
- 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;
- }
-#else /* !USE_PAM && !HAVE_OSF_SIA */
- /* Try authentication with the password. */
- authenticated = auth_password(pw, password);
-#endif /* USE_PAM */
+ /* Try authentication with the password. */
+ authenticated = PRIVSEP(auth_password(authctxt, password));
memset(password, 0, strlen(password));
xfree(password);
break;
-#ifdef SKEY /* ISSUE: Is this right? we don't define
- having skey_authentication in
- servconf.h by default so I assume
- we need to deal with this via #ifdef
- in some reasonable way */
case SSH_CMSG_AUTH_TIS:
debug("rcvd SSH_CMSG_AUTH_TIS");
- if (options.skey_authentication == 1) {
- char *challenge = get_challenge(authctxt, authctxt->style);
+ if (options.challenge_response_authentication == 1) {
+ char *challenge = get_challenge(authctxt);
if (challenge != NULL) {
debug("sending challenge '%s'", challenge);
packet_start(SSH_SMSG_AUTH_TIS_CHALLENGE);
packet_put_cstring(challenge);
+ xfree(challenge);
packet_send();
packet_write_wait();
continue;
break;
case SSH_CMSG_AUTH_TIS_RESPONSE:
debug("rcvd SSH_CMSG_AUTH_TIS_RESPONSE");
- if (options.skey_authentication == 1) {
+ if (options.challenge_response_authentication == 1) {
char *response = packet_get_string(&dlen);
debug("got response '%s'", response);
- packet_integrity_check(plen, 4 + dlen, type);
+ packet_check_eom();
authenticated = verify_response(authctxt, response);
memset(response, 'r', dlen);
xfree(response);
}
break;
-#endif /* ISSUE: End of wrong SKEY defines */
default:
/*
log("Unknown message during authentication: type %d", type);
break;
}
+#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 /* ISSUE: Right place? */
- if (authenticated &&
- !check_nt_auth(type == SSH_CMSG_AUTH_PASSWORD,pw->pw_uid)) {
+#ifdef HAVE_CYGWIN
+ if (authenticated &&
+ !check_nt_auth(type == SSH_CMSG_AUTH_PASSWORD, pw)) {
packet_disconnect("Authentication rejected for uid %d.",
- (int)pw->pw_uid);
+ pw == NULL ? -1 : pw->pw_uid);
authenticated = 0;
}
-#endif
-
+#else
/* Special handling for root */
- if (authenticated && authctxt->pw->pw_uid == 0 && !auth_root_allowed())
+ if (authenticated && authctxt->pw->pw_uid == 0 &&
+ !auth_root_allowed(get_authname(type)))
authenticated = 0;
-
-#ifdef USE_PAM /* ISSUE: Right place? */
- if (authenticated && !do_pam_account(pw->pw_name, client_user))
+#endif
+#ifdef USE_PAM
+ if (!use_privsep && authenticated &&
+ !do_pam_account(pw->pw_name, client_user))
authenticated = 0;
#endif
if (authenticated)
return;
- if (authctxt->failures++ > AUTH_FAIL_MAX) {
-#ifdef WITH_AIXAUTHENTICATE
- loginfailed(user,get_canonical_hostname(),"ssh");
-#endif /* WITH_AIXAUTHENTICATE */
+ if (authctxt->failures++ > AUTH_FAIL_MAX) {
packet_disconnect(AUTH_FAIL_MSG, authctxt->user);
}
* Performs authentication of an incoming connection. Session key has already
* been exchanged and encryption is enabled.
*/
-void
-do_authentication()
+Authctxt *
+do_authentication(void)
{
Authctxt *authctxt;
- struct passwd *pw;
- int plen;
u_int ulen;
char *user, *style = NULL;
/* Get the name of the user that we wish to log in as. */
- packet_read_expect(&plen, SSH_CMSG_USER);
+ packet_read_expect(SSH_CMSG_USER);
/* Get the user name. */
user = packet_get_string(&ulen);
- packet_integrity_check(plen, (4 + ulen), SSH_CMSG_USER);
+ packet_check_eom();
if ((style = strchr(user, ':')) != NULL)
- *style++ = 0;
+ *style++ = '\0';
+
+#ifdef KRB5
+ /* XXX - SSH.com Kerberos v5 braindeath. */
+ if ((datafellows & SSH_BUG_K5USER) &&
+ options.kerberos_authentication) {
+ char *p;
+ if ((p = strchr(user, '@')) != NULL)
+ *p = '\0';
+ }
+#endif
authctxt = authctxt_new();
authctxt->user = user;
authctxt->style = style;
- setproctitle("%s", user);
-
-#ifdef AFS
- /* If machine has AFS, set process authentication group. */
- if (k_hasafs()) {
- k_setpag();
- k_unlog();
- }
-#endif /* AFS */
-
/* Verify that the user is a valid user. */
- pw = getpwnam(user);
- if (pw && allowed_user(pw)) {
+ if ((authctxt->pw = PRIVSEP(getpwnamallow(user))) != NULL)
authctxt->valid = 1;
- pw = pwcopy(pw);
- } else {
+ else
debug("do_authentication: illegal user %s", user);
- pw = NULL;
- }
- authctxt->pw = pw;
+
+ setproctitle("%s%s", authctxt->pw ? user : "unknown",
+ use_privsep ? " [net]" : "");
#ifdef USE_PAM
- if (pw)
- start_pam(pw);
+ PRIVSEP(start_pam(authctxt->pw == NULL ? "NOUSER" : user));
#endif
/*
* the server. (Unless you are running Windows)
*/
#ifndef HAVE_CYGWIN
- if (getuid() != 0 && pw && pw->pw_uid != getuid())
+ if (!use_privsep && getuid() != 0 && authctxt->pw &&
+ authctxt->pw->pw_uid != getuid())
packet_disconnect("Cannot change user when server not running as root.");
#endif
/*
- * Loop until the user has been authenticated or the connection is
- * closed, do_authloop() returns only if authentication is successful
- */
+ * 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_send();
packet_write_wait();
-#ifdef WITH_AIXAUTHENTICATE
- /* We don't have a pty yet, so just label the line as "ssh" */
- if (loginsuccess(authctxt->user,get_canonical_hostname(),"ssh",&aixloginmsg) < 0)
- aixloginmsg = NULL;
-#endif /* WITH_AIXAUTHENTICATE */
-
- xfree(authctxt->user);
- xfree(authctxt);
-
- /* Perform session preparation. */
- do_authenticated(pw);
+ return (authctxt);
}