1 files changed, 461 insertions, 164 deletions

diff --git a/sshconnect2.c b/sshconnect2.c
index 642b34b9e..933c223ec 100644
--- a/sshconnect2.c
+++ b/sshconnect2.c
@@ -23,7 +23,9 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: sshconnect2.c,v 1.114 2003/04/01 10:22:21 markus Exp $");
+RCSID("$OpenBSD: sshconnect2.c,v 1.124 2003/08/25 10:33:33 djm Exp $");
+
+#include "openbsd-compat/sys-queue.h"
 
 #include "ssh.h"
 #include "ssh2.h"
@@ -48,6 +50,10 @@ RCSID("$OpenBSD: sshconnect2.c,v 1.114 2003/04/01 10:22:21 markus Exp $");
 #include "msg.h"
 #include "pathnames.h"
 
+#ifdef GSSAPI
+#include "ssh-gss.h"
+#endif
+
 /* import */
 extern char *client_version_string;
 extern char *server_version_string;
@@ -58,7 +64,7 @@ extern Options options;
  */
 
 u_char *session_id2 = NULL;
-int session_id2_len = 0;
+u_int session_id2_len = 0;
 
 char *xxx_host;
 struct sockaddr *xxx_hostaddr;
@@ -82,7 +88,7 @@ ssh_kex2(char *host, struct sockaddr *hostaddr)
         xxx_hostaddr = hostaddr;
 
         if (options.ciphers == (char *)-1) {
-                log("No valid ciphers for protocol version 2 given, using defaults.");
+                logit("No valid ciphers for protocol version 2 given, using defaults.");
                 options.ciphers = NULL;
         }
         if (options.ciphers != NULL) {
@@ -108,6 +114,9 @@ ssh_kex2(char *host, struct sockaddr *hostaddr)
                 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
                     options.hostkeyalgorithms;
 
+        if (options.rekey_limit)
+                packet_set_rekey_limit(options.rekey_limit);
+
         /* start key exchange */
         kex = kex_setup(myproposal);
         kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
@@ -138,10 +147,18 @@ ssh_kex2(char *host, struct sockaddr *hostaddr)
 
 typedef struct Authctxt Authctxt;
 typedef struct Authmethod Authmethod;
-
-typedef int sign_cb_fn(
-    Authctxt *authctxt, Key *key,
-    u_char **sigp, u_int *lenp, u_char *data, u_int datalen);
+typedef struct identity Identity;
+typedef struct idlist Idlist;
+
+struct identity {
+        TAILQ_ENTRY(identity) next;
+        AuthenticationConnection *ac;   /* set if agent supports key */
+        Key     *key;                   /* public/private key */
+        char    *filename;              /* comment for agent-only keys */
+        int     tried;
+        int     isprivate;              /* key points to the private key */
+};
+TAILQ_HEAD(idlist, identity);
 
 struct Authctxt {
         const char *server_user;
@@ -152,14 +169,14 @@ struct Authctxt {
         int success;
         char *authlist;
         /* pubkey */
-        Key *last_key;
-        sign_cb_fn *last_key_sign;
-        int last_key_hint;
+        Idlist keys;
         AuthenticationConnection *agent;
         /* hostbased */
         Sensitive *sensitive;
         /* kbd-interactive */
         int info_req_seen;
+        /* generic */
+        void *methoddata;
 };
 struct Authmethod {
         char    *name;          /* string to compare against server's list */
@@ -181,17 +198,35 @@ int	userauth_pubkey(Authctxt *);
 int     userauth_passwd(Authctxt *);
 int     userauth_kbdint(Authctxt *);
 int     userauth_hostbased(Authctxt *);
+int     userauth_kerberos(Authctxt *);
+
+#ifdef GSSAPI
+int     userauth_gssapi(Authctxt *authctxt);
+void    input_gssapi_response(int type, u_int32_t, void *);
+void    input_gssapi_token(int type, u_int32_t, void *);
+void    input_gssapi_hash(int type, u_int32_t, void *);
+void    input_gssapi_error(int, u_int32_t, void *);
+void    input_gssapi_errtok(int, u_int32_t, void *);
+#endif
 
 void    userauth(Authctxt *, char *);
 
-static int sign_and_send_pubkey(Authctxt *, Key *, sign_cb_fn *);
-static void clear_auth_state(Authctxt *);
+static int sign_and_send_pubkey(Authctxt *, Identity *);
+static void pubkey_prepare(Authctxt *);
+static void pubkey_cleanup(Authctxt *);
+static Key *load_identity_file(char *);
 
 static Authmethod *authmethod_get(char *authlist);
 static Authmethod *authmethod_lookup(const char *name);
 static char *authmethods_get(void);
 
 Authmethod authmethods[] = {
+#ifdef GSSAPI
+        {"gssapi",
+                userauth_gssapi,
+                &options.gss_authentication,
+                NULL},
+#endif
         {"hostbased",
                 userauth_hostbased,
                 &options.hostbased_authentication,
@@ -248,7 +283,7 @@ ssh_userauth2(const char *local_user, const char *server_user, char *host,
 
         /* setup authentication context */
         memset(&authctxt, 0, sizeof(authctxt));
-        authctxt.agent = ssh_get_authentication_connection();
+        pubkey_prepare(&authctxt);
         authctxt.server_user = server_user;
         authctxt.local_user = local_user;
         authctxt.host = host;
@@ -256,6 +291,7 @@ ssh_userauth2(const char *local_user, const char *server_user, char *host,
         authctxt.success = 0;
         authctxt.method = authmethod_lookup("none");
         authctxt.authlist = NULL;
+        authctxt.methoddata = NULL;
         authctxt.sensitive = sensitive;
         authctxt.info_req_seen = 0;
         if (authctxt.method == NULL)
@@ -270,14 +306,19 @@ ssh_userauth2(const char *local_user, const char *server_user, char *host,
         dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
         dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt);     /* loop until success */
 
-        if (authctxt.agent != NULL)
-                ssh_close_authentication_connection(authctxt.agent);
+        pubkey_cleanup(&authctxt);
+        dispatch_range(SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
 
         debug("Authentication succeeded (%s).", authctxt.method->name);
 }
+
 void
 userauth(Authctxt *authctxt, char *authlist)
 {
+        if (authctxt->methoddata) {
+                xfree(authctxt->methoddata);
+                authctxt->methoddata = NULL;
+        }
         if (authlist == NULL) {
                 authlist = authctxt->authlist;
         } else {
@@ -290,6 +331,12 @@ userauth(Authctxt *authctxt, char *authlist)
                 if (method == NULL)
                         fatal("Permission denied (%s).", authlist);
                 authctxt->method = method;
+
+                /* reset the per method handler */
+                dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN,
+                    SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
+
+                /* and try new method */
                 if (method->userauth(authctxt) != 0) {
                         debug2("we sent a %s packet, wait for reply", method->name);
                         break;
@@ -314,7 +361,7 @@ input_userauth_banner(int type, u_int32_t seq, void *ctxt)
         debug3("input_userauth_banner");
         msg = packet_get_string(NULL);
         lang = packet_get_string(NULL);
-        fprintf(stderr, "%s", msg);
+        logit("%s", msg);
         xfree(msg);
         xfree(lang);
 }
@@ -327,7 +374,8 @@ input_userauth_success(int type, u_int32_t seq, void *ctxt)
                 fatal("input_userauth_success: no authentication context");
         if (authctxt->authlist)
                 xfree(authctxt->authlist);
-        clear_auth_state(authctxt);
+        if (authctxt->methoddata)
+                xfree(authctxt->methoddata);
         authctxt->success = 1;                  /* break out */
 }
 
@@ -346,10 +394,9 @@ input_userauth_failure(int type, u_int32_t seq, void *ctxt)
         packet_check_eom();
 
         if (partial != 0)
-                log("Authenticated with partial success.");
+                logit("Authenticated with partial success.");
         debug("Authentications that can continue: %s", authlist);
 
-        clear_auth_state(authctxt);
         userauth(authctxt, authlist);
 }
 void
@@ -357,6 +404,7 @@ input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt)
 {
         Authctxt *authctxt = ctxt;
         Key *key = NULL;
+        Identity *id = NULL;
         Buffer b;
         int pktype, sent = 0;
         u_int alen, blen;
@@ -379,55 +427,267 @@ input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt)
         }
         packet_check_eom();
 
-        debug("Server accepts key: pkalg %s blen %u lastkey %p hint %d",
-            pkalg, blen, authctxt->last_key, authctxt->last_key_hint);
+        debug("Server accepts key: pkalg %s blen %u", pkalg, blen);
 
-        do {
-                if (authctxt->last_key == NULL ||
-                    authctxt->last_key_sign == NULL) {
-                        debug("no last key or no sign cb");
-                        break;
-                }
-                if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) {
-                        debug("unknown pkalg %s", pkalg);
-                        break;
-                }
-                if ((key = key_from_blob(pkblob, blen)) == NULL) {
-                        debug("no key from blob. pkalg %s", pkalg);
-                        break;
-                }
-                if (key->type != pktype) {
-                        error("input_userauth_pk_ok: type mismatch "
-                            "for decoded key (received %d, expected %d)",
-                            key->type, pktype);
-                        break;
-                }
-                fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX);
-                debug2("input_userauth_pk_ok: fp %s", fp);
-                xfree(fp);
-                if (!key_equal(key, authctxt->last_key)) {
-                        debug("key != last_key");
+        if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) {
+                debug("unknown pkalg %s", pkalg);
+                goto done;
+        }
+        if ((key = key_from_blob(pkblob, blen)) == NULL) {
+                debug("no key from blob. pkalg %s", pkalg);
+                goto done;
+        }
+        if (key->type != pktype) {
+                error("input_userauth_pk_ok: type mismatch "
+                    "for decoded key (received %d, expected %d)",
+                    key->type, pktype);
+                goto done;
+        }
+        fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX);
+        debug2("input_userauth_pk_ok: fp %s", fp);
+        xfree(fp);
+
+        TAILQ_FOREACH(id, &authctxt->keys, next) {
+                if (key_equal(key, id->key)) {
+                        sent = sign_and_send_pubkey(authctxt, id);
                         break;
                 }
-                sent = sign_and_send_pubkey(authctxt, key,
-                   authctxt->last_key_sign);
-        } while (0);
-
+        }
+done:
         if (key != NULL)
                 key_free(key);
         xfree(pkalg);
         xfree(pkblob);
 
-        /* unregister */
-        clear_auth_state(authctxt);
-        dispatch_set(SSH2_MSG_USERAUTH_PK_OK, NULL);
-
         /* try another method if we did not send a packet */
         if (sent == 0)
                 userauth(authctxt, NULL);
+}
+
+#ifdef GSSAPI
+int 
+userauth_gssapi(Authctxt *authctxt)
+{
+        Gssctxt *gssctxt = NULL;
+        static gss_OID_set supported = NULL;
+        static int mech = 0;
+        OM_uint32 min;
+        int ok = 0;
+
+        /* Try one GSSAPI method at a time, rather than sending them all at
+         * once. */
+
+        if (supported == NULL)
+                gss_indicate_mechs(&min, &supported);
+
+        /* Check to see if the mechanism is usable before we offer it */
+        while (mech<supported->count && !ok) {
+                if (gssctxt)
+                        ssh_gssapi_delete_ctx(&gssctxt);
+                ssh_gssapi_build_ctx(&gssctxt);
+                ssh_gssapi_set_oid(gssctxt, &supported->elements[mech]);
+
+                /* My DER encoding requires length<128 */
+                if (supported->elements[mech].length < 128 &&
+                    !GSS_ERROR(ssh_gssapi_import_name(gssctxt,
+                    authctxt->host))) {
+                        ok = 1; /* Mechanism works */
+                } else {
+                        mech++;
+                }
+        }
+
+        if (!ok) return 0;
+
+        authctxt->methoddata=(void *)gssctxt;
+
+        packet_start(SSH2_MSG_USERAUTH_REQUEST);
+        packet_put_cstring(authctxt->server_user);
+        packet_put_cstring(authctxt->service);
+        packet_put_cstring(authctxt->method->name);
 
+        packet_put_int(1);
+
+        /* Some servers encode the OID incorrectly (as we used to) */
+        if (datafellows & SSH_BUG_GSSAPI_BER) {
+                packet_put_string(supported->elements[mech].elements,
+                    supported->elements[mech].length);
+        } else {
+                packet_put_int((supported->elements[mech].length)+2);
+                packet_put_char(SSH_GSS_OIDTYPE);
+                packet_put_char(supported->elements[mech].length);
+                packet_put_raw(supported->elements[mech].elements,
+                    supported->elements[mech].length);
+        }
+
+        packet_send();
+
+        dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
+        dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
+        dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
+        dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
+
+        mech++; /* Move along to next candidate */
+
+        return 1;
+}
+
+void
+input_gssapi_response(int type, u_int32_t plen, void *ctxt)
+{
+        Authctxt *authctxt = ctxt;
+        Gssctxt *gssctxt;
+        OM_uint32 status, ms;
+        int oidlen;
+        char *oidv;
+        gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
+
+        if (authctxt == NULL)
+                fatal("input_gssapi_response: no authentication context");
+        gssctxt = authctxt->methoddata;
+
+        /* Setup our OID */
+        oidv = packet_get_string(&oidlen);
+
+        if (datafellows & SSH_BUG_GSSAPI_BER) {
+                if (!ssh_gssapi_check_oid(gssctxt, oidv, oidlen))
+                        fatal("Server returned different OID than expected");
+        } else {
+                if(oidv[0] != SSH_GSS_OIDTYPE || oidv[1] != oidlen-2) {
+                        debug("Badly encoded mechanism OID received");
+                        userauth(authctxt, NULL);
+                        xfree(oidv);
+                        return;
+                }
+                if (!ssh_gssapi_check_oid(gssctxt, oidv+2, oidlen-2))
+                        fatal("Server returned different OID than expected");
+        }
+
+        packet_check_eom();
+
+        xfree(oidv);
+
+        status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
+            GSS_C_NO_BUFFER, &send_tok, NULL);
+        if (GSS_ERROR(status)) {
+                if (send_tok.length > 0) {
+                        packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
+                        packet_put_string(send_tok.value, send_tok.length);
+                        packet_send();
+                        gss_release_buffer(&ms, &send_tok);
+                }
+                /* Start again with next method on list */
+                debug("Trying to start again");
+                userauth(authctxt, NULL);
+                return;
+        }
+
+        /* We must have data to send */
+        packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
+        packet_put_string(send_tok.value, send_tok.length);
+        packet_send();
+        gss_release_buffer(&ms, &send_tok);
 }
 
+void
+input_gssapi_token(int type, u_int32_t plen, void *ctxt)
+{
+        Authctxt *authctxt = ctxt;
+        Gssctxt *gssctxt;
+        gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
+        gss_buffer_desc recv_tok;
+        OM_uint32 status, ms;
+        u_int slen;
+
+        if (authctxt == NULL)
+                fatal("input_gssapi_response: no authentication context");
+        gssctxt = authctxt->methoddata;
+
+        recv_tok.value = packet_get_string(&slen);
+        recv_tok.length = slen; /* safe typecast */
+
+        packet_check_eom();
+
+        status=ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
+            &recv_tok, &send_tok, NULL);
+
+        xfree(recv_tok.value);
+
+        if (GSS_ERROR(status)) {
+                if (send_tok.length > 0) {
+                        packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
+                        packet_put_string(send_tok.value, send_tok.length);
+                        packet_send();
+                        gss_release_buffer(&ms, &send_tok);
+                }
+                /* Start again with the next method in the list */
+                userauth(authctxt, NULL);
+                return;
+        }
+
+        if (send_tok.length > 0) {
+                packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
+                packet_put_string(send_tok.value, send_tok.length);
+                packet_send();
+                gss_release_buffer(&ms, &send_tok);
+        }
+
+        if (status == GSS_S_COMPLETE) {
+                /* If that succeeded, send a exchange complete message */
+                packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE);
+                packet_send();
+        }
+}
+
+void
+input_gssapi_errtok(int type, u_int32_t plen, void *ctxt)
+{
+        Authctxt *authctxt = ctxt;
+        Gssctxt *gssctxt;
+        gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
+        gss_buffer_desc recv_tok;
+        OM_uint32 status, ms;
+        u_int len;
+
+        if (authctxt == NULL)
+                fatal("input_gssapi_response: no authentication context");
+        gssctxt = authctxt->methoddata;
+
+        recv_tok.value = packet_get_string(&len);
+        recv_tok.length = len;
+
+        packet_check_eom();
+
+        /* Stick it into GSSAPI and see what it says */
+        status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
+                                     &recv_tok, &send_tok, NULL);
+
+        xfree(recv_tok.value);
+        gss_release_buffer(&ms, &send_tok);
+
+        /* Server will be returning a failed packet after this one */
+}
+
+void
+input_gssapi_error(int type, u_int32_t plen, void *ctxt)
+{
+        OM_uint32 maj, min;
+        char *msg;
+        char *lang;
+
+        maj=packet_get_int();
+        min=packet_get_int();
+        msg=packet_get_string(NULL);
+        lang=packet_get_string(NULL);
+
+        packet_check_eom();
+
+        debug("Server GSSAPI Error:\n%s\n", msg);
+        xfree(msg);
+        xfree(lang);
+}
+#endif /* GSSAPI */
+
 int
 userauth_none(Authctxt *authctxt)
 {
@@ -491,7 +751,7 @@ input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt)
         info = packet_get_string(NULL);
         lang = packet_get_string(NULL);
         if (strlen(info) > 0)
-                log("%s", info);
+                logit("%s", info);
         xfree(info);
         xfree(lang);
         packet_start(SSH2_MSG_USERAUTH_REQUEST);
@@ -523,7 +783,7 @@ input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt)
                 if (strcmp(password, retype) != 0) {
                         memset(password, 0, strlen(password));
                         xfree(password);
-                        log("Mismatch; try again, EOF to quit.");
+                        logit("Mismatch; try again, EOF to quit.");
                         password = NULL;
                 }
                 memset(retype, 0, strlen(retype));
@@ -539,34 +799,44 @@ input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt)
             &input_userauth_passwd_changereq);
 }
 
-static void
-clear_auth_state(Authctxt *authctxt)
+static int
+identity_sign(Identity *id, u_char **sigp, u_int *lenp,
+    u_char *data, u_int datalen)
 {
-        /* XXX clear authentication state */
-        dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, NULL);
+        Key *prv;
+        int ret;
 
-        if (authctxt->last_key != NULL && authctxt->last_key_hint == -1) {
-                debug3("clear_auth_state: key_free %p", authctxt->last_key);
-                key_free(authctxt->last_key);
-        }
-        authctxt->last_key = NULL;
-        authctxt->last_key_hint = -2;
-        authctxt->last_key_sign = NULL;
+        /* the agent supports this key */
+        if (id->ac)
+                return (ssh_agent_sign(id->ac, id->key, sigp, lenp,
+                    data, datalen));
+        /*
+         * we have already loaded the private key or
+         * the private key is stored in external hardware
+         */
+        if (id->isprivate || (id->key->flags & KEY_FLAG_EXT))
+                return (key_sign(id->key, sigp, lenp, data, datalen));
+        /* load the private key from the file */
+        if ((prv = load_identity_file(id->filename)) == NULL)
+                return (-1);
+        ret = key_sign(prv, sigp, lenp, data, datalen);
+        key_free(prv);
+        return (ret);
 }
 
 static int
-sign_and_send_pubkey(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback)
+sign_and_send_pubkey(Authctxt *authctxt, Identity *id)
 {
         Buffer b;
         u_char *blob, *signature;
         u_int bloblen, slen;
-        int skip = 0;
+        u_int skip = 0;
         int ret = -1;
         int have_sig = 1;
 
         debug3("sign_and_send_pubkey");
 
-        if (key_to_blob(k, &blob, &bloblen) == 0) {
+        if (key_to_blob(id->key, &blob, &bloblen) == 0) {
                 /* we cannot handle this key */
                 debug3("sign_and_send_pubkey: cannot handle key");
                 return 0;
@@ -591,12 +861,12 @@ sign_and_send_pubkey(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback)
         } else {
                 buffer_put_cstring(&b, authctxt->method->name);
                 buffer_put_char(&b, have_sig);
-                buffer_put_cstring(&b, key_ssh_name(k));
+                buffer_put_cstring(&b, key_ssh_name(id->key));
         }
         buffer_put_string(&b, blob, bloblen);
 
         /* generate signature */
-        ret = (*sign_callback)(authctxt, k, &signature, &slen,
+        ret = identity_sign(id, &signature, &slen,
             buffer_ptr(&b), buffer_len(&b));
         if (ret == -1) {
                 xfree(blob);
@@ -616,7 +886,7 @@ sign_and_send_pubkey(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback)
                 buffer_put_cstring(&b, authctxt->method->name);
                 buffer_put_char(&b, have_sig);
                 if (!(datafellows & SSH_BUG_PKAUTH))
-                        buffer_put_cstring(&b, key_ssh_name(k));
+                        buffer_put_cstring(&b, key_ssh_name(id->key));
                 buffer_put_string(&b, blob, bloblen);
         }
         xfree(blob);
@@ -640,23 +910,19 @@ sign_and_send_pubkey(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback)
 }
 
 static int
-send_pubkey_test(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback,
-    int hint)
+send_pubkey_test(Authctxt *authctxt, Identity *id)
 {
         u_char *blob;
         u_int bloblen, have_sig = 0;
 
         debug3("send_pubkey_test");
 
-        if (key_to_blob(k, &blob, &bloblen) == 0) {
+        if (key_to_blob(id->key, &blob, &bloblen) == 0) {
                 /* we cannot handle this key */
                 debug3("send_pubkey_test: cannot handle key");
                 return 0;
         }
         /* register callback for USERAUTH_PK_OK message */
-        authctxt->last_key_sign = sign_callback;
-        authctxt->last_key_hint = hint;
-        authctxt->last_key = k;
         dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
 
         packet_start(SSH2_MSG_USERAUTH_REQUEST);
@@ -665,7 +931,7 @@ send_pubkey_test(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback,
         packet_put_cstring(authctxt->method->name);
         packet_put_char(have_sig);
         if (!(datafellows & SSH_BUG_PKAUTH))
-                packet_put_cstring(key_ssh_name(k));
+                packet_put_cstring(key_ssh_name(id->key));
         packet_put_string(blob, bloblen);
         xfree(blob);
         packet_send();
@@ -710,103 +976,134 @@ load_identity_file(char *filename)
         return private;
 }
 
-static int
-identity_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, u_int *lenp,
-    u_char *data, u_int datalen)
-{
-        Key *private;
-        int idx, ret;
-
-        idx = authctxt->last_key_hint;
-        if (idx < 0)
-                return -1;
-
-        /* private key is stored in external hardware */
-        if (options.identity_keys[idx]->flags & KEY_FLAG_EXT)
-                return key_sign(options.identity_keys[idx], sigp, lenp, data, datalen);
-
-        private = load_identity_file(options.identity_files[idx]);
-        if (private == NULL)
-                return -1;
-        ret = key_sign(private, sigp, lenp, data, datalen);
-        key_free(private);
-        return ret;
-}
-
-static int
-agent_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, u_int *lenp,
-    u_char *data, u_int datalen)
-{
-        return ssh_agent_sign(authctxt->agent, key, sigp, lenp, data, datalen);
-}
-
-static int
-key_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, u_int *lenp,
-    u_char *data, u_int datalen)
+/*
+ * try keys in the following order:
+ *      1. agent keys that are found in the config file
+ *      2. other agent keys
+ *      3. keys that are only listed in the config file
+ */
+static void
+pubkey_prepare(Authctxt *authctxt)
 {
-        return key_sign(key, sigp, lenp, data, datalen);
+        Identity *id;
+        Idlist agent, files, *preferred;
+        Key *key;
+        AuthenticationConnection *ac;
+        char *comment;
+        int i, found;
+
+        TAILQ_INIT(&agent);     /* keys from the agent */
+        TAILQ_INIT(&files);     /* keys from the config file */
+        preferred = &authctxt->keys;
+        TAILQ_INIT(preferred);  /* preferred order of keys */
+
+        /* list of keys stored in the filesystem */
+        for (i = 0; i < options.num_identity_files; i++) {
+                key = options.identity_keys[i];
+                if (key && key->type == KEY_RSA1)
+                        continue;
+                options.identity_keys[i] = NULL;
+                id = xmalloc(sizeof(*id));
+                memset(id, 0, sizeof(*id));
+                id->key = key;
+                id->filename = xstrdup(options.identity_files[i]);
+                TAILQ_INSERT_TAIL(&files, id, next);
+        }
+        /* list of keys supported by the agent */
+        if ((ac = ssh_get_authentication_connection())) {
+                for (key = ssh_get_first_identity(ac, &comment, 2);
+                    key != NULL;
+                    key = ssh_get_next_identity(ac, &comment, 2)) {
+                        found = 0;
+                        TAILQ_FOREACH(id, &files, next) {
+                                /* agent keys from the config file are preferred */ 
+                                if (key_equal(key, id->key)) {
+                                        key_free(key);
+                                        xfree(comment);
+                                        TAILQ_REMOVE(&files, id, next);
+                                        TAILQ_INSERT_TAIL(preferred, id, next);
+                                        id->ac = ac;
+                                        found = 1;
+                                        break;
+                                }
+                        }
+                        if (!found) {
+                                id = xmalloc(sizeof(*id));
+                                memset(id, 0, sizeof(*id));
+                                id->key = key;
+                                id->filename = comment;
+                                id->ac = ac;
+                                TAILQ_INSERT_TAIL(&agent, id, next);
+                        }
+                }
+                /* append remaining agent keys */
+                for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) {
+                        TAILQ_REMOVE(&agent, id, next);
+                        TAILQ_INSERT_TAIL(preferred, id, next);
+                }
+                authctxt->agent = ac;
+        }
+        /* append remaining keys from the config file */
+        for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) {
+                TAILQ_REMOVE(&files, id, next);
+                TAILQ_INSERT_TAIL(preferred, id, next);
+        }
+        TAILQ_FOREACH(id, preferred, next) {
+                debug2("key: %s (%p)", id->filename, id->key);
+        }
 }
 
-static int
-userauth_pubkey_agent(Authctxt *authctxt)
+static void
+pubkey_cleanup(Authctxt *authctxt)
 {
-        static int called = 0;
-        int ret = 0;
-        char *comment;
-        Key *k;
-
-        if (called == 0) {
-                if (ssh_get_num_identities(authctxt->agent, 2) == 0)
-                        debug2("userauth_pubkey_agent: no keys at all");
-                called = 1;
-        }
-        k = ssh_get_next_identity(authctxt->agent, &comment, 2);
-        if (k == NULL) {
-                debug2("userauth_pubkey_agent: no more keys");
-        } else {
-                debug("Offering agent key: %s", comment);
-                xfree(comment);
-                ret = send_pubkey_test(authctxt, k, agent_sign_cb, -1);
-                if (ret == 0)
-                        key_free(k);
+        Identity *id;
+
+        if (authctxt->agent != NULL)
+                ssh_close_authentication_connection(authctxt->agent);
+        for (id = TAILQ_FIRST(&authctxt->keys); id;
+            id = TAILQ_FIRST(&authctxt->keys)) {
+                TAILQ_REMOVE(&authctxt->keys, id, next);
+                if (id->key)
+                        key_free(id->key);
+                if (id->filename)
+                        xfree(id->filename);
+                xfree(id);
         }
-        if (ret == 0)
-                debug2("userauth_pubkey_agent: no message sent");
-        return ret;
 }
 
 int
 userauth_pubkey(Authctxt *authctxt)
 {
-        static int idx = 0;
+        Identity *id;
         int sent = 0;
-        Key *key;
-        char *filename;
 
-        if (authctxt->agent != NULL) {
-                do {
-                        sent = userauth_pubkey_agent(authctxt);
-                } while (!sent && authctxt->agent->howmany > 0);
-        }
-        while (!sent && idx < options.num_identity_files) {
-                key = options.identity_keys[idx];
-                filename = options.identity_files[idx];
-                if (key == NULL) {
-                        debug("Trying private key: %s", filename);
-                        key = load_identity_file(filename);
-                        if (key != NULL) {
-                                sent = sign_and_send_pubkey(authctxt, key,
-                                    key_sign_cb);
-                                key_free(key);
+        while ((id = TAILQ_FIRST(&authctxt->keys))) {
+                if (id->tried++)
+                        return (0);
+                TAILQ_REMOVE(&authctxt->keys, id, next);
+                TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
+                /*
+                 * send a test message if we have the public key. for
+                 * encrypted keys we cannot do this and have to load the
+                 * private key instead
+                 */
+                if (id->key && id->key->type != KEY_RSA1) {
+                        debug("Offering public key: %s", id->filename);
+                        sent = send_pubkey_test(authctxt, id);
+                } else if (id->key == NULL) {
+                        debug("Trying private key: %s", id->filename);
+                        id->key = load_identity_file(id->filename);
+                        if (id->key != NULL) {
+                                id->isprivate = 1;
+                                sent = sign_and_send_pubkey(authctxt, id);
+                                key_free(id->key);
+                                id->key = NULL;
                         }
-                } else if (key->type != KEY_RSA1) {
-                        debug("Offering public key: %s", filename);
-                        sent = send_pubkey_test(authctxt, key,
-                            identity_sign_cb, idx);
                 }
-                idx++;
+                if (sent)
+                        return (sent);
         }
-        return sent;
+        return (0);
 }
 
 /*
@@ -862,9 +1159,9 @@ input_userauth_info_req(int type, u_int32_t seq, void *ctxt)
         inst = packet_get_string(NULL);
         lang = packet_get_string(NULL);
         if (strlen(name) > 0)
-                log("%s", name);
+                logit("%s", name);
         if (strlen(inst) > 0)
-                log("%s", inst);
+                logit("%s", inst);
         xfree(name);
         xfree(inst);
         xfree(lang);