- Merge big update to OpenSSH-2.0 from OpenBSD CVS
[README.openssh2]
- interop w/ F-secure windows client
- sync documentation
- ssh_host_dsa_key not ssh_dsa_key
[auth-rsa.c]
- missing fclose
[auth.c authfile.c compat.c dsa.c dsa.h hostfile.c key.c key.h radix.c]
[readconf.c readconf.h ssh-add.c ssh-keygen.c ssh.c ssh.h sshconnect.c]
[sshd.c uuencode.c uuencode.h authfile.h]
- add DSA pubkey auth and other SSH2 fixes. use ssh-keygen -[xX]
for trading keys with the real and the original SSH, directly from the
people who invented the SSH protocol.
[auth.c auth.h authfile.c sshconnect.c auth1.c auth2.c sshconnect.h]
[sshconnect1.c sshconnect2.c]
- split auth/sshconnect in one file per protocol version
[sshconnect2.c]
- remove debug
[uuencode.c]
- add trailing =
[version.h]
- OpenSSH-2.0
[ssh-keygen.1 ssh-keygen.c]
- add -R flag: exit code indicates if RSA is alive
[sshd.c]
- remove unused
silent if -Q is specified
[ssh.h]
- host key becomes /etc/ssh_host_dsa_key
[readconf.c servconf.c ]
- ssh/sshd default to proto 1 and 2
[uuencode.c]
- remove debug
[auth2.c ssh-keygen.c sshconnect2.c sshd.c]
- xfree DSA blobs
[auth2.c serverloop.c session.c]
- cleanup logging for sshd/2, respect PasswordAuth no
[sshconnect2.c]
- less debug, respect .ssh/config
[README.openssh2 channels.c channels.h]
- clientloop.c session.c ssh.c
- support for x11-fwding, client+server
diff --git a/auth.c b/auth.c
index 4c6f32b..3bfcfd8 100644
--- a/auth.c
+++ b/auth.c
@@ -5,7 +5,7 @@
*/
#include "includes.h"
-RCSID("$OpenBSD: auth.c,v 1.4 2000/04/14 10:30:29 markus Exp $");
+RCSID("$OpenBSD: auth.c,v 1.6 2000/04/26 21:28:31 markus Exp $");
#include "xmalloc.h"
#include "rsa.h"
@@ -40,7 +40,7 @@
* If the user's shell is not executable, false will be returned.
* Otherwise true is returned.
*/
-static int
+int
allowed_user(struct passwd * pw)
{
struct stat st;
@@ -118,685 +118,3 @@
/* We found no reason not to let this user try to log on... */
return 1;
}
-
-/*
- * convert ssh auth msg type into description
- */
-char *
-get_authname(int type)
-{
- static char buf[1024];
- switch (type) {
- case SSH_CMSG_AUTH_PASSWORD:
- return "password";
- case SSH_CMSG_AUTH_RSA:
- return "rsa";
- case SSH_CMSG_AUTH_RHOSTS_RSA:
- return "rhosts-rsa";
- case SSH_CMSG_AUTH_RHOSTS:
- return "rhosts";
-#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);
- return buf;
-}
-
-#define AUTH_FAIL_MAX 6
-#define AUTH_FAIL_LOG (AUTH_FAIL_MAX/2)
-#define AUTH_FAIL_MSG "Too many authentication failures for %.100s"
-
-/*
- * The user does not exist or access is denied,
- * but fake indication that authentication is needed.
- */
-void
-do_fake_authloop1(char *user)
-{
- int attempt = 0;
-
- log("Faking authloop for illegal user %.200s from %.200s port %d",
- user,
- get_remote_ipaddr(),
- get_remote_port());
-
-#ifdef WITH_AIXAUTHENTICATE
- if (strncmp(get_authname(type),"password",
- strlen(get_authname(type))) == 0)
- loginfailed(pw->pw_name,get_canonical_hostname(),"ssh");
-#endif /* WITH_AIXAUTHENTICATE */
-
- /* Indicate that authentication is needed. */
- packet_start(SSH_SMSG_FAILURE);
- packet_send();
- packet_write_wait();
-
- /*
- * Keep reading packets, and always respond with a failure. This is
- * to avoid disclosing whether such a user really exists.
- */
- for (attempt = 1;; attempt++) {
- /* Read a packet. This will not return if the client disconnects. */
- int plen;
-#ifndef SKEY
- (void)packet_read(&plen);
-#else /* SKEY */
- int type = packet_read(&plen);
- unsigned int dlen;
- char *password, *skeyinfo;
- /* Try to send a fake s/key challenge. */
- if (options.skey_authentication == 1 &&
- (skeyinfo = skey_fake_keyinfo(user)) != NULL) {
- password = NULL;
- if (type == SSH_CMSG_AUTH_TIS) {
- packet_start(SSH_SMSG_AUTH_TIS_CHALLENGE);
- packet_put_string(skeyinfo, strlen(skeyinfo));
- packet_send();
- packet_write_wait();
- continue;
- } else if (type == SSH_CMSG_AUTH_PASSWORD &&
- options.password_authentication &&
- (password = packet_get_string(&dlen)) != NULL &&
- dlen == 5 &&
- strncasecmp(password, "s/key", 5) == 0 ) {
- packet_send_debug(skeyinfo);
- }
- if (password != NULL)
- xfree(password);
- }
-#endif
- if (attempt > AUTH_FAIL_MAX)
- packet_disconnect(AUTH_FAIL_MSG, user);
-
- /*
- * Send failure. This should be indistinguishable from a
- * failed authentication.
- */
- packet_start(SSH_SMSG_FAILURE);
- packet_send();
- packet_write_wait();
- }
- /* NOTREACHED */
- abort();
-}
-
-/*
- * read packets and try to authenticate local user *pw.
- * return if authentication is successfull
- */
-void
-do_authloop(struct passwd * pw)
-{
- int attempt = 0;
- unsigned int bits;
- RSA *client_host_key;
- BIGNUM *n;
- char *client_user = NULL, *password = NULL;
- char user[1024];
- unsigned int dlen;
- int plen, nlen, elen;
- unsigned int ulen;
- int type = 0;
- void (*authlog) (const char *fmt,...) = verbose;
-
- /* Indicate that authentication is needed. */
- packet_start(SSH_SMSG_FAILURE);
- packet_send();
- packet_write_wait();
-
- for (attempt = 1;; attempt++) {
- int authenticated = 0;
- strlcpy(user, "", sizeof user);
-
- /* Get a packet from the client. */
- type = packet_read(&plen);
-
- /* Process the packet. */
- switch (type) {
-#ifdef AFS
- case SSH_CMSG_HAVE_KERBEROS_TGT:
- if (!options.kerberos_tgt_passing) {
- /* packet_get_all(); */
- 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 %s", pw->pw_name);
- xfree(tgt);
- }
- continue;
-
- case SSH_CMSG_HAVE_AFS_TOKEN:
- if (!options.afs_token_passing || !k_hasafs()) {
- /* packet_get_all(); */
- 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 %s", pw->pw_name);
- xfree(token_string);
- }
- continue;
-#endif /* AFS */
-#ifdef KRB4
- case SSH_CMSG_AUTH_KERBEROS:
- if (!options.kerberos_authentication) {
- /* packet_get_all(); */
- verbose("Kerberos authentication disabled.");
- break;
- } else {
- /* Try Kerberos v4 authentication. */
- KTEXT_ST auth;
- char *tkt_user = NULL;
- char *kdata = packet_get_string((unsigned 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);
-
- authenticated = auth_krb4(pw->pw_name, &auth, &tkt_user);
-
- if (authenticated) {
- snprintf(user, sizeof user, " tktuser %s", tkt_user);
- xfree(tkt_user);
- }
- }
- break;
-#endif /* KRB4 */
-
- case SSH_CMSG_AUTH_RHOSTS:
- if (!options.rhosts_authentication) {
- verbose("Rhosts authentication disabled.");
- break;
- }
- /*
- * Get client user name. Note that we just have to
- * trust the client; this is one reason why rhosts
- * authentication is insecure. (Another is
- * IP-spoofing on a local network.)
- */
- client_user = packet_get_string(&ulen);
- packet_integrity_check(plen, 4 + ulen, type);
-
- /* Try to authenticate using /etc/hosts.equiv and
- .rhosts. */
- authenticated = auth_rhosts(pw, client_user);
-
- snprintf(user, sizeof user, " ruser %s", client_user);
- break;
-
- case SSH_CMSG_AUTH_RHOSTS_RSA:
- if (!options.rhosts_rsa_authentication) {
- verbose("Rhosts with RSA authentication disabled.");
- break;
- }
- /*
- * Get client user name. Note that we just have to
- * trust the client; root on the client machine can
- * claim to be any 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");
- bits = packet_get_int();
- packet_get_bignum(client_host_key->e, &elen);
- packet_get_bignum(client_host_key->n, &nlen);
-
- if (bits != BN_num_bits(client_host_key->n))
- error("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);
-
- authenticated = auth_rhosts_rsa(pw, client_user, client_host_key);
- RSA_free(client_host_key);
-
- snprintf(user, sizeof user, " ruser %s", client_user);
- break;
-
- case SSH_CMSG_AUTH_RSA:
- if (!options.rsa_authentication) {
- verbose("RSA authentication disabled.");
- break;
- }
- /* RSA authentication requested. */
- n = BN_new();
- packet_get_bignum(n, &nlen);
- packet_integrity_check(plen, nlen, type);
- authenticated = auth_rsa(pw, n);
- BN_clear_free(n);
- break;
-
- case SSH_CMSG_AUTH_PASSWORD:
- if (!options.password_authentication) {
- verbose("Password authentication disabled.");
- break;
- }
- /*
- * Read user password. It is in plain text, but was
- * transmitted over the encrypted channel so it is
- * not visible to an outside observer.
- */
- password = packet_get_string(&dlen);
- packet_integrity_check(plen, 4 + dlen, type);
-
-#ifdef USE_PAM
- /* Do PAM auth with password */
- authenticated = auth_pam_password(pw, password);
-#else /* USE_PAM */
- /* Try authentication with the password. */
- authenticated = auth_password(pw, 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 = skey_keyinfo(pw->pw_name);
- if (skeyinfo == NULL) {
- debug("generating fake skeyinfo for %.100s.", pw->pw_name);
- skeyinfo = skey_fake_keyinfo(pw->pw_name);
- }
- if (skeyinfo != NULL) {
- /* we send our s/key- in tis-challenge messages */
- debug("sending challenge '%s'", skeyinfo);
- packet_start(SSH_SMSG_AUTH_TIS_CHALLENGE);
- packet_put_string(skeyinfo, strlen(skeyinfo));
- 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) {
- char *response = packet_get_string(&dlen);
- debug("skey response == '%s'", response);
- packet_integrity_check(plen, 4 + dlen, type);
- authenticated = (skey_haskey(pw->pw_name) == 0 &&
- skey_passcheck(pw->pw_name, response) != -1);
- xfree(response);
- }
- break;
-#else
- case SSH_CMSG_AUTH_TIS:
- /* TIS Authentication is unsupported */
- log("TIS authentication unsupported.");
- break;
-#endif
-
- default:
- /*
- * Any unknown messages will be ignored (and failure
- * returned) during authentication.
- */
- log("Unknown message during authentication: type %d", type);
- break;
- }
-
- /*
- * 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_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 %.200s from %.200s port %d%s",
- authenticated ? "Accepted" : "Failed",
- get_authname(type),
- pw->pw_uid == 0 ? "ROOT" : pw->pw_name,
- get_remote_ipaddr(),
- get_remote_port(),
- user);
-
-#ifdef USE_PAM
- if (authenticated) {
- if (!do_pam_account(pw->pw_name, client_user)) {
- if (client_user != NULL) {
- xfree(client_user);
- client_user = NULL;
- }
- do_fake_authloop1(pw->pw_name);
- }
- return;
- }
-#else /* USE_PAM */
- if (authenticated) {
- return;
- }
-#endif /* USE_PAM */
-
- if (client_user != NULL) {
- xfree(client_user);
- client_user = NULL;
- }
-
- if (attempt > AUTH_FAIL_MAX)
- packet_disconnect(AUTH_FAIL_MSG, pw->pw_name);
-
- /* Send a message indicating that the authentication attempt failed. */
- packet_start(SSH_SMSG_FAILURE);
- packet_send();
- packet_write_wait();
- }
-}
-
-/*
- * Performs authentication of an incoming connection. Session key has already
- * been exchanged and encryption is enabled.
- */
-void
-do_authentication()
-{
- struct passwd *pw, pwcopy;
- int plen;
- unsigned int ulen;
- char *user;
-#ifdef WITH_AIXAUTHENTICATE
- char *loginmsg;
-#endif /* WITH_AIXAUTHENTICATE */
-
- /* Get the name of the user that we wish to log in as. */
- packet_read_expect(&plen, SSH_CMSG_USER);
-
- /* Get the user name. */
- user = packet_get_string(&ulen);
- packet_integrity_check(plen, (4 + ulen), SSH_CMSG_USER);
-
- 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))
- do_fake_authloop1(user);
- xfree(user);
-
- /* 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;
- pwcopy.pw_dir = xstrdup(pw->pw_dir);
- pwcopy.pw_shell = xstrdup(pw->pw_shell);
- pw = &pwcopy;
-
-#ifdef USE_PAM
- start_pam(pw);
-#endif
-
- /*
- * If we are not running as root, the user must have the same uid as
- * the server.
- */
- if (getuid() != 0 && pw->pw_uid != getuid())
- packet_disconnect("Cannot change user when server not running as root.");
-
- debug("Attempting authentication for %.100s.", pw->pw_name);
-
- /* 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, "")) {
-#else /* USE_PAM */
- auth_password(pw, "")) {
-#endif /* USE_PAM */
- /* Authentication with empty password succeeded. */
- log("Login for user %s from %.100s, accepted without authentication.",
- pw->pw_name, get_remote_ipaddr());
- } else {
- /* Loop until the user has been authenticated or the
- connection is closed, do_authloop() returns only if
- authentication is successfull */
- do_authloop(pw);
- }
-
- /* The user has been authenticated and accepted. */
-#ifdef WITH_AIXAUTHENTICATE
- loginsuccess(user,get_canonical_hostname(),"ssh",&loginmsg);
-#endif /* WITH_AIXAUTHENTICATE */
- packet_start(SSH_SMSG_SUCCESS);
- packet_send();
- packet_write_wait();
-
- /* Perform session preparation. */
- do_authenticated(pw);
-}
-
-
-void input_service_request(int type, int plen);
-void input_userauth_request(int type, int plen);
-void ssh2_pty_cleanup(void);
-
-typedef struct Authctxt Authctxt;
-struct Authctxt {
- char *user;
- char *service;
- struct passwd pw;
- int valid;
-};
-static Authctxt *authctxt = NULL;
-static int userauth_success = 0;
-
-struct passwd*
-auth_get_user(void)
-{
- return (authctxt != NULL && authctxt->valid) ? &authctxt->pw : NULL;
-}
-struct passwd*
-auth_set_user(char *u, char *s)
-{
- struct passwd *pw, *copy;
-
- if (authctxt == NULL) {
- authctxt = xmalloc(sizeof(*authctxt));
- authctxt->valid = 0;
- authctxt->user = xstrdup(u);
- authctxt->service = xstrdup(s);
- setproctitle("%s", u);
- pw = getpwnam(u);
- if (!pw || !allowed_user(pw)) {
- log("auth_set_user: bad user %s", u);
- return NULL;
- }
-#ifdef USE_PAM
- start_pam(pw);
-#endif
- copy = &authctxt->pw;
- 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;
- copy->pw_dir = xstrdup(pw->pw_dir);
- copy->pw_shell = xstrdup(pw->pw_shell);
- authctxt->valid = 1;
- } else {
- if (strcmp(u, authctxt->user) != 0 ||
- strcmp(s, authctxt->service) != 0) {
- log("auth_set_user: missmatch: (%s,%s)!=(%s,%s)",
- u, s, authctxt->user, authctxt->service);
- return NULL;
- }
- }
- return auth_get_user();
-}
-
-static void
-protocol_error(int type, int plen)
-{
- log("auth: protocol error: type %d plen %d", type, plen);
- packet_start(SSH2_MSG_UNIMPLEMENTED);
- packet_put_int(0);
- packet_send();
- packet_write_wait();
-}
-void
-input_service_request(int type, int plen)
-{
- unsigned int len;
- int accept = 0;
- char *service = packet_get_string(&len);
- packet_done();
-
- if (strcmp(service, "ssh-userauth") == 0) {
- if (!userauth_success) {
- accept = 1;
- /* now we can handle user-auth requests */
- dispatch_set(SSH2_MSG_USERAUTH_REQUEST, &input_userauth_request);
- }
- }
- /* XXX all other service requests are denied */
-
- if (accept) {
- packet_start(SSH2_MSG_SERVICE_ACCEPT);
- packet_put_cstring(service);
- packet_send();
- packet_write_wait();
- } else {
- debug("bad service request %s", service);
- packet_disconnect("bad service request %s", service);
- }
- xfree(service);
-}
-void
-input_userauth_request(int type, int plen)
-{
- static int try = 0;
- unsigned int len;
- int c, authenticated = 0;
- char *user, *service, *method;
- struct passwd *pw;
-
- if (++try == AUTH_FAIL_MAX)
- packet_disconnect("too many failed userauth_requests");
-
- user = packet_get_string(&len);
- service = packet_get_string(&len);
- method = packet_get_string(&len);
- debug("userauth-request for user %s service %s method %s", user, service, method);
-
- /* XXX we only allow the ssh-connection service */
- pw = auth_set_user(user, service);
- if (pw && strcmp(service, "ssh-connection")==0) {
- if (strcmp(method, "none") == 0 && try == 1) {
- packet_done();
-#ifdef USE_PAM
- /* Do PAM auth with password */
- authenticated = auth_pam_password(pw, "");
-#else /* USE_PAM */
- /* Try authentication with the password. */
- authenticated = auth_password(pw, "");
-#endif /* USE_PAM */
- } else if (strcmp(method, "password") == 0) {
- char *password;
- c = packet_get_char();
- if (c)
- debug("password change not supported");
- password = packet_get_string(&len);
- packet_done();
-#ifdef USE_PAM
- /* Do PAM auth with password */
- authenticated = auth_pam_password(pw, password);
-#else /* USE_PAM */
- /* Try authentication with the password. */
- authenticated = auth_password(pw, password);
-#endif /* USE_PAM */
- memset(password, 0, len);
- xfree(password);
- } else if (strcmp(method, "publickey") == 0) {
- /* XXX TODO */
- char *pkalg, *pkblob, *sig;
- int have_sig = packet_get_char();
- pkalg = packet_get_string(&len);
- pkblob = packet_get_string(&len);
- if (have_sig) {
- sig = packet_get_string(&len);
- /* test for correct signature */
- packet_done();
- xfree(sig);
- } else {
- packet_done();
- /* test whether pkalg/pkblob are acceptable */
- }
- xfree(pkalg);
- xfree(pkblob);
- }
- }
- /* XXX check if other auth methods are needed */
- if (authenticated) {
- /* turn off userauth */
- dispatch_set(SSH2_MSG_USERAUTH_REQUEST, &protocol_error);
- packet_start(SSH2_MSG_USERAUTH_SUCCESS);
- packet_send();
- packet_write_wait();
- log("userauth success for %s", user);
- /* now we can break out */
- userauth_success = 1;
- } else {
- packet_start(SSH2_MSG_USERAUTH_FAILURE);
- packet_put_cstring("password");
- packet_put_char(0); /* partial success */
- packet_send();
- packet_write_wait();
- }
- xfree(service);
- xfree(user);
- xfree(method);
-}
-void
-do_authentication2()
-{
- dispatch_init(&protocol_error);
- dispatch_set(SSH2_MSG_SERVICE_REQUEST, &input_service_request);
- dispatch_run(DISPATCH_BLOCK, &userauth_success);
- do_authenticated2();
-}