]> andersk Git - openssh.git/blobdiff - auth2.c
- provos@cvs.openbsd.org 2002/03/18 01:12:14
[openssh.git] / auth2.c
diff --git a/auth2.c b/auth2.c
index eb04ae75be1a6115a97bfe79a150af223c4ce947..b57fda216de8068b4f7b970f407fdb43c3e9b5bd 100644 (file)
--- a/auth2.c
+++ b/auth2.c
@@ -23,7 +23,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: auth2.c,v 1.72 2001/11/07 22:41:51 markus Exp $");
+RCSID("$OpenBSD: auth2.c,v 1.87 2002/03/18 01:12:14 provos Exp $");
 
 #include <openssl/evp.h>
 
@@ -57,10 +57,6 @@ extern ServerOptions options;
 extern u_char *session_id2;
 extern int session_id2_len;
 
-#ifdef WITH_AIXAUTHENTICATE
-extern char *aixloginmsg;
-#endif
-
 static Authctxt        *x_authctxt = NULL;
 static int one = 1;
 
@@ -73,9 +69,8 @@ struct Authmethod {
 
 /* protocol */
 
-static void input_service_request(int, int, void *);
-static void input_userauth_request(int, int, void *);
-static void protocol_error(int, int, void *);
+static void input_service_request(int, u_int32_t, void *);
+static void input_userauth_request(int, u_int32_t, void *);
 
 /* helper */
 static Authmethod *authmethod_lookup(const char *);
@@ -114,8 +109,8 @@ Authmethod authmethods[] = {
  * loop until authctxt->success == TRUE
  */
 
-void
-do_authentication2()
+Authctxt *
+do_authentication2(void)
 {
        Authctxt *authctxt = authctxt_new();
 
@@ -127,30 +122,21 @@ do_authentication2()
        if (options.pam_authentication_via_kbd_int)
                options.kbd_interactive_authentication = 1;
 
-       dispatch_init(&protocol_error);
+       dispatch_init(&dispatch_protocol_error);
        dispatch_set(SSH2_MSG_SERVICE_REQUEST, &input_service_request);
        dispatch_run(DISPATCH_BLOCK, &authctxt->success, authctxt);
-       do_authenticated(authctxt);
-}
 
-static void
-protocol_error(int type, int plen, void *ctxt)
-{
-       log("auth: protocol error: type %d plen %d", type, plen);
-       packet_start(SSH2_MSG_UNIMPLEMENTED);
-       packet_put_int(0);
-       packet_send();
-       packet_write_wait();
+       return (authctxt);
 }
 
 static void
-input_service_request(int type, int plen, void *ctxt)
+input_service_request(int type, u_int32_t seq, void *ctxt)
 {
        Authctxt *authctxt = ctxt;
        u_int len;
        int accept = 0;
        char *service = packet_get_string(&len);
-       packet_done();
+       packet_check_eom();
 
        if (authctxt == NULL)
                fatal("input_service_request: no authctxt");
@@ -177,7 +163,7 @@ input_service_request(int type, int plen, void *ctxt)
 }
 
 static void
-input_userauth_request(int type, int plen, void *ctxt)
+input_userauth_request(int type, u_int32_t seq, void *ctxt)
 {
        Authctxt *authctxt = ctxt;
        Authmethod *m = NULL;
@@ -199,8 +185,8 @@ input_userauth_request(int type, int plen, void *ctxt)
        if (authctxt->attempt++ == 0) {
                /* setup auth context */
                struct passwd *pw = NULL;
-               pw = getpwnam(user);
-               if (pw && allowed_user(pw) && strcmp(service, "ssh-connection")==0) {
+               pw = getpwnamallow(user);
+               if (pw && strcmp(service, "ssh-connection")==0) {
                        authctxt->pw = pwcopy(pw);
                        authctxt->valid = 1;
                        debug2("input_userauth_request: setting up authctxt for %s", user);
@@ -224,14 +210,8 @@ input_userauth_request(int type, int plen, void *ctxt)
                    authctxt->user, authctxt->service, user, service);
        }
        /* reset state */
-       dispatch_set(SSH2_MSG_USERAUTH_INFO_RESPONSE, &protocol_error);
+       auth2_challenge_stop(authctxt);
        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);
@@ -275,15 +255,21 @@ userauth_finish(Authctxt *authctxt, int authenticated, char *method)
        /* XXX todo: check if multiple auth methods are needed */
        if (authenticated == 1) {
                /* turn off userauth */
-               dispatch_set(SSH2_MSG_USERAUTH_REQUEST, &protocol_error);
+               dispatch_set(SSH2_MSG_USERAUTH_REQUEST, &dispatch_protocol_ignore);
                packet_start(SSH2_MSG_USERAUTH_SUCCESS);
                packet_send();
                packet_write_wait();
                /* now we can break out */
                authctxt->success = 1;
        } else {
-               if (authctxt->failures++ > AUTH_FAIL_MAX)
+               if (authctxt->failures++ > AUTH_FAIL_MAX) {
+#ifdef WITH_AIXAUTHENTICATE
+                       loginfailed(authctxt->user,
+                           get_canonical_hostname(options.verify_reverse_mapping),
+                           "ssh");
+#endif /* WITH_AIXAUTHENTICATE */
                        packet_disconnect(AUTH_FAIL_MSG, authctxt->user);
+               }
                methods = authmethods_get();
                packet_start(SSH2_MSG_USERAUTH_FAILURE);
                packet_put_cstring(methods);
@@ -332,14 +318,14 @@ userauth_none(Authctxt *authctxt)
        Authmethod *m = authmethod_lookup("none");
        if (m != NULL)
                m->enabled = NULL;
-       packet_done();
+       packet_check_eom();
        userauth_banner();
 
        if (authctxt->valid == 0)
                return(0);
 
 #ifdef HAVE_CYGWIN
-       if (check_nt_auth(1, authctxt->pw->pw_uid) == 0)
+       if (check_nt_auth(1, authctxt->pw) == 0)
                return(0);
 #endif
 #ifdef USE_PAM
@@ -362,10 +348,10 @@ userauth_passwd(Authctxt *authctxt)
        if (change)
                log("password change not supported");
        password = packet_get_string(&len);
-       packet_done();
+       packet_check_eom();
        if (authctxt->valid &&
 #ifdef HAVE_CYGWIN
-               check_nt_auth(1, authctxt->pw->pw_uid) &&
+           check_nt_auth(1, authctxt->pw) &&
 #endif
 #ifdef USE_PAM
            auth_pam_password(authctxt->pw, password) == 1)
@@ -388,7 +374,7 @@ userauth_kbdint(Authctxt *authctxt)
 
        lang = packet_get_string(NULL);
        devs = packet_get_string(NULL);
-       packet_done();
+       packet_check_eom();
 
        debug("keyboard-interactive devs %s", devs);
 
@@ -402,7 +388,7 @@ userauth_kbdint(Authctxt *authctxt)
        xfree(devs);
        xfree(lang);
 #ifdef HAVE_CYGWIN
-       if (check_nt_auth(0, authctxt->pw->pw_uid) == 0)
+       if (check_nt_auth(0, authctxt->pw) == 0)
                return(0);
 #endif
        return authenticated;
@@ -412,8 +398,9 @@ static int
 userauth_pubkey(Authctxt *authctxt)
 {
        Buffer b;
-       Key *key;
-       char *pkalg, *pkblob, *sig;
+       Key *key = NULL;
+       char *pkalg;
+       u_char *pkblob, *sig;
        u_int alen, blen, slen;
        int have_sig, pktype;
        int authenticated = 0;
@@ -439,76 +426,84 @@ userauth_pubkey(Authctxt *authctxt)
        pktype = key_type_from_name(pkalg);
        if (pktype == KEY_UNSPEC) {
                /* this is perfectly legal */
-               log("userauth_pubkey: unsupported public key algorithm: %s", pkalg);
-               xfree(pkalg);
-               xfree(pkblob);
-               return 0;
+               log("userauth_pubkey: unsupported public key algorithm: %s",
+                   pkalg);
+               goto done;
        }
        key = key_from_blob(pkblob, blen);
-       if (key != NULL) {
-               if (have_sig) {
-                       sig = packet_get_string(&slen);
-                       packet_done();
-                       buffer_init(&b);
-                       if (datafellows & SSH_OLD_SESSIONID) {
-                               buffer_append(&b, session_id2, session_id2_len);
-                       } else {
-                               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,
-                           datafellows & SSH_BUG_PKSERVICE ?
-                           "ssh-userauth" :
-                           authctxt->service);
-                       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);
+       if (key == NULL) {
+               error("userauth_pubkey: cannot decode key: %s", pkalg);
+               goto done;
+       }
+       if (key->type != pktype) {
+               error("userauth_pubkey: type mismatch for decoded key "
+                   "(received %d, expected %d)", key->type, pktype);
+               goto done;
+       }
+       if (have_sig) {
+               sig = packet_get_string(&slen);
+               packet_check_eom();
+               buffer_init(&b);
+               if (datafellows & SSH_OLD_SESSIONID) {
+                       buffer_append(&b, session_id2, session_id2_len);
+               } else {
+                       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,
+                   datafellows & SSH_BUG_PKSERVICE ?
+                   "ssh-userauth" :
+                   authctxt->service);
+               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);
+               buffer_dump(&b);
 #endif
-                       /* test for correct signature */
-                       if (user_key_allowed(authctxt->pw, key) &&
-                           key_verify(key, sig, slen, buffer_ptr(&b), buffer_len(&b)) == 1)
-                               authenticated = 1;
-                       buffer_clear(&b);
-                       xfree(sig);
-               } else {
-                       debug("test whether pkalg/pkblob are acceptable");
-                       packet_done();
-
-                       /* XXX fake reply and always send PK_OK ? */
-                       /*
-                        * XXX this allows testing whether a user is allowed
-                        * to login: if you happen to have a valid pubkey this
-                        * message is sent. the message is NEVER sent at all
-                        * if a user is not allowed to login. is this an
-                        * issue? -markus
-                        */
-                       if (user_key_allowed(authctxt->pw, key)) {
-                               packet_start(SSH2_MSG_USERAUTH_PK_OK);
-                               packet_put_string(pkalg, alen);
-                               packet_put_string(pkblob, blen);
-                               packet_send();
-                               packet_write_wait();
-                               authctxt->postponed = 1;
-                       }
+               /* test for correct signature */
+               if (user_key_allowed(authctxt->pw, key) &&
+                   key_verify(key, sig, slen, buffer_ptr(&b), buffer_len(&b)) == 1)
+                       authenticated = 1;
+               buffer_clear(&b);
+               xfree(sig);
+       } else {
+               debug("test whether pkalg/pkblob are acceptable");
+               packet_check_eom();
+
+               /* XXX fake reply and always send PK_OK ? */
+               /*
+                * XXX this allows testing whether a user is allowed
+                * to login: if you happen to have a valid pubkey this
+                * message is sent. the message is NEVER sent at all
+                * if a user is not allowed to login. is this an
+                * issue? -markus
+                */
+               if (user_key_allowed(authctxt->pw, key)) {
+                       packet_start(SSH2_MSG_USERAUTH_PK_OK);
+                       packet_put_string(pkalg, alen);
+                       packet_put_string(pkblob, blen);
+                       packet_send();
+                       packet_write_wait();
+                       authctxt->postponed = 1;
                }
-               if (authenticated != 1)
-                       auth_clear_options();
-               key_free(key);
        }
+       if (authenticated != 1)
+               auth_clear_options();
+done:
        debug2("userauth_pubkey: authenticated %d pkalg %s", authenticated, pkalg);
+       if (key != NULL)
+               key_free(key);
        xfree(pkalg);
        xfree(pkblob);
 #ifdef HAVE_CYGWIN
-       if (check_nt_auth(0, authctxt->pw->pw_uid) == 0)
+       if (check_nt_auth(0, authctxt->pw) == 0)
                return(0);
 #endif
        return authenticated;
@@ -518,8 +513,9 @@ static int
 userauth_hostbased(Authctxt *authctxt)
 {
        Buffer b;
-       Key *key;
-       char *pkalg, *pkblob, *sig, *cuser, *chost, *service;
+       Key *key = NULL;
+       char *pkalg, *cuser, *chost, *service;
+       u_char *pkblob, *sig;
        u_int alen, blen, slen;
        int pktype;
        int authenticated = 0;
@@ -552,7 +548,12 @@ userauth_hostbased(Authctxt *authctxt)
        }
        key = key_from_blob(pkblob, blen);
        if (key == NULL) {
-               debug("userauth_hostbased: cannot decode key: %s", pkalg);
+               error("userauth_hostbased: cannot decode key: %s", pkalg);
+               goto done;
+       }
+       if (key->type != pktype) {
+               error("userauth_hostbased: type mismatch for decoded key "
+                   "(received %d, expected %d)", key->type, pktype);
                goto done;
        }
        service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
@@ -577,10 +578,10 @@ userauth_hostbased(Authctxt *authctxt)
                authenticated = 1;
 
        buffer_clear(&b);
-       key_free(key);
-
 done:
        debug2("userauth_hostbased: authenticated %d", authenticated);
+       if (key != NULL)
+               key_free(key);
        xfree(pkalg);
        xfree(pkblob);
        xfree(cuser);
@@ -603,31 +604,22 @@ static char *
 authmethods_get(void)
 {
        Authmethod *method = NULL;
-       u_int size = 0;
+       Buffer b;
        char *list;
 
+       buffer_init(&b);
        for (method = authmethods; method->name != NULL; method++) {
                if (strcmp(method->name, "none") == 0)
                        continue;
                if (method->enabled != NULL && *(method->enabled) != 0) {
-                       if (size != 0)
-                               size += strlen(DELIM);
-                       size += strlen(method->name);
-               }
-       }
-       size++;                 /* trailing '\0' */
-       list = xmalloc(size);
-       list[0] = '\0';
-
-       for (method = authmethods; method->name != NULL; method++) {
-               if (strcmp(method->name, "none") == 0)
-                       continue;
-               if (method->enabled != NULL && *(method->enabled) != 0) {
-                       if (list[0] != '\0')
-                               strlcat(list, DELIM, size);
-                       strlcat(list, method->name, size);
+                       if (buffer_len(&b) > 0)
+                               buffer_append(&b, ",", 1);
+                       buffer_append(&b, method->name, strlen(method->name));
                }
        }
+       buffer_append(&b, "\0", 1);
+       list = xstrdup(buffer_ptr(&b));
+       buffer_free(&b);
        return list;
 }
 
@@ -655,6 +647,7 @@ user_key_allowed2(struct passwd *pw, Key *key, char *file)
        u_long linenum = 0;
        struct stat st;
        Key *found;
+       char *fp;
 
        if (pw == NULL)
                return 0;
@@ -722,6 +715,10 @@ user_key_allowed2(struct passwd *pw, Key *key, char *file)
                        found_key = 1;
                        debug("matching key found: file %s, line %lu",
                            file, linenum);
+                       fp = key_fingerprint(found, SSH_FP_MD5, SSH_FP_HEX);
+                       verbose("Found matching %s key: %s",
+                           key_type(found), fp);
+                       xfree(fp);
                        break;
                }
        }
@@ -759,9 +756,10 @@ hostbased_key_allowed(struct passwd *pw, const char *cuser, char *chost,
     Key *key)
 {
        const char *resolvedname, *ipaddr, *lookup;
-       int host_status, len;
+       HostStatus host_status;
+       int len;
 
-       resolvedname = get_canonical_hostname(options.reverse_mapping_check);
+       resolvedname = get_canonical_hostname(options.verify_reverse_mapping);
        ipaddr = get_remote_ipaddr();
 
        debug2("userauth_hostbased: chost %s resolvedname %s ipaddr %s",
@@ -799,4 +797,3 @@ hostbased_key_allowed(struct passwd *pw, const char *cuser, char *chost,
 
        return (host_status == HOST_OK);
 }
-
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