1 files changed, 361 insertions, 212 deletions

diff --git a/sshconnect2.c b/sshconnect2.c
index 7b478f16d..faa8ec589 100644
--- a/sshconnect2.c
+++ b/sshconnect2.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshconnect2.c,v 1.210 2014/07/15 15:54:14 millert Exp $ */
+/* $OpenBSD: sshconnect2.c,v 1.223 2015/01/30 11:43:14 djm Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  * Copyright (c) 2008 Damien Miller.  All rights reserved.
@@ -70,6 +70,7 @@
 #include "pathnames.h"
 #include "uidswap.h"
 #include "hostfile.h"
+#include "ssherr.h"
 
 #ifdef GSSAPI
 #include "ssh-gss.h"
@@ -90,10 +91,8 @@ u_int session_id2_len = 0;
 char *xxx_host;
 struct sockaddr *xxx_hostaddr;
 
-Kex *xxx_kex = NULL;
-
 static int
-verify_host_key_callback(Key *hostkey)
+verify_host_key_callback(Key *hostkey, struct ssh *ssh)
 {
         if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1)
                 fatal("Host key verification failed.");
@@ -131,16 +130,17 @@ order_hostkeyalgs(char *host, struct sockaddr *hostaddr, u_short port)
         } while (0)
 
         while ((alg = strsep(&avail, ",")) && *alg != '\0') {
-                if ((ktype = key_type_from_name(alg)) == KEY_UNSPEC)
+                if ((ktype = sshkey_type_from_name(alg)) == KEY_UNSPEC)
                         fatal("%s: unknown alg %s", __func__, alg);
                 if (lookup_key_in_hostkeys_by_type(hostkeys,
-                    key_type_plain(ktype), NULL))
+                    sshkey_type_plain(ktype), NULL))
                         ALG_APPEND(first, alg);
                 else
                         ALG_APPEND(last, alg);
         }
 #undef ALG_APPEND
-        xasprintf(&ret, "%s%s%s", first, *first == '\0' ? "" : ",", last);
+        xasprintf(&ret, "%s%s%s", first,
+            (*first == '\0' || *last == '\0') ? "" : ",", last);
         if (*first != '\0')
                 debug3("%s: prefer hostkeyalgs: %s", __func__, first);
 
@@ -157,7 +157,8 @@ void
 ssh_kex2(char *host, struct sockaddr *hostaddr, u_short port)
 {
         char *myproposal[PROPOSAL_MAX] = { KEX_CLIENT };
-        Kex *kex;
+        struct kex *kex;
+        int r;
 
 #ifdef GSSAPI
         char *orig = NULL, *gss = NULL;
@@ -240,13 +241,17 @@ ssh_kex2(char *host, struct sockaddr *hostaddr, u_short port)
                     (time_t)options.rekey_interval);
 
         /* start key exchange */
-        kex = kex_setup(myproposal);
+        if ((r = kex_setup(active_state, myproposal)) != 0)
+                fatal("kex_setup: %s", ssh_err(r));
+        kex = active_state->kex;
 #ifdef WITH_OPENSSL
         kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
         kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
         kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
         kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
+# ifdef OPENSSL_HAS_ECC
         kex->kex[KEX_ECDH_SHA2] = kexecdh_client;
+# endif
 #endif
         kex->kex[KEX_C25519_SHA256] = kexc25519_client;
 #ifdef GSSAPI
@@ -273,9 +278,7 @@ ssh_kex2(char *host, struct sockaddr *hostaddr, u_short port)
         }
 #endif
 
-        xxx_kex = kex;
-
-        dispatch_run(DISPATCH_BLOCK, &kex->done, kex);
+        dispatch_run(DISPATCH_BLOCK, &kex->done, active_state);
 
         if (options.use_roaming && !kex->roaming) {
                 debug("Roaming not allowed by server");
@@ -298,15 +301,15 @@ ssh_kex2(char *host, struct sockaddr *hostaddr, u_short port)
  * Authenticate user
  */
 
-typedef struct Authctxt Authctxt;
-typedef struct Authmethod Authmethod;
+typedef struct cauthctxt Authctxt;
+typedef struct cauthmethod Authmethod;
 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 */
+        int     agent_fd;               /* >=0 if agent supports key */
+        struct sshkey   *key;           /* public/private key */
         char    *filename;              /* comment for agent-only keys */
         int     tried;
         int     isprivate;              /* key points to the private key */
@@ -314,25 +317,29 @@ struct identity {
 };
 TAILQ_HEAD(idlist, identity);
 
-struct Authctxt {
+struct cauthctxt {
         const char *server_user;
         const char *local_user;
         const char *host;
         const char *service;
-        Authmethod *method;
+        struct cauthmethod *method;
         sig_atomic_t success;
         char *authlist;
+        int attempt;
         /* pubkey */
-        Idlist keys;
-        AuthenticationConnection *agent;
+        struct idlist keys;
+        int agent_fd;
         /* hostbased */
         Sensitive *sensitive;
+        char *oktypes, *ktypes;
+        const char *active_ktype;
         /* kbd-interactive */
         int info_req_seen;
         /* generic */
         void *methoddata;
 };
-struct Authmethod {
+
+struct cauthmethod {
         char    *name;          /* string to compare against server's list */
         int     (*userauth)(Authctxt *authctxt);
         void    (*cleanup)(Authctxt *authctxt);
@@ -340,14 +347,14 @@ struct Authmethod {
         int     *batch_flag;    /* flag in option struct that disables method */
 };
 
-void    input_userauth_success(int, u_int32_t, void *);
-void    input_userauth_success_unexpected(int, u_int32_t, void *);
-void    input_userauth_failure(int, u_int32_t, void *);
-void    input_userauth_banner(int, u_int32_t, void *);
-void    input_userauth_error(int, u_int32_t, void *);
-void    input_userauth_info_req(int, u_int32_t, void *);
-void    input_userauth_pk_ok(int, u_int32_t, void *);
-void    input_userauth_passwd_changereq(int, u_int32_t, void *);
+int     input_userauth_success(int, u_int32_t, void *);
+int     input_userauth_success_unexpected(int, u_int32_t, void *);
+int     input_userauth_failure(int, u_int32_t, void *);
+int     input_userauth_banner(int, u_int32_t, void *);
+int     input_userauth_error(int, u_int32_t, void *);
+int     input_userauth_info_req(int, u_int32_t, void *);
+int     input_userauth_pk_ok(int, u_int32_t, void *);
+int     input_userauth_passwd_changereq(int, u_int32_t, void *);
 
 int     userauth_none(Authctxt *);
 int     userauth_pubkey(Authctxt *);
@@ -357,11 +364,11 @@ int	userauth_hostbased(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 *);
+int     input_gssapi_response(int type, u_int32_t, void *);
+int     input_gssapi_token(int type, u_int32_t, void *);
+int     input_gssapi_hash(int type, u_int32_t, void *);
+int     input_gssapi_error(int, u_int32_t, void *);
+int     input_gssapi_errtok(int, u_int32_t, void *);
 int     userauth_gsskeyex(Authctxt *authctxt);
 #endif
 
@@ -460,7 +467,9 @@ ssh_userauth2(const char *local_user, const char *server_user, char *host,
         authctxt.authlist = NULL;
         authctxt.methoddata = NULL;
         authctxt.sensitive = sensitive;
+        authctxt.active_ktype = authctxt.oktypes = authctxt.ktypes = NULL;
         authctxt.info_req_seen = 0;
+        authctxt.agent_fd = -1;
         if (authctxt.method == NULL)
                 fatal("ssh_userauth2: internal error: cannot send userauth none request");
 
@@ -515,15 +524,16 @@ userauth(Authctxt *authctxt, char *authlist)
 }
 
 /* ARGSUSED */
-void
+int
 input_userauth_error(int type, u_int32_t seq, void *ctxt)
 {
         fatal("input_userauth_error: bad message during authentication: "
             "type %d", type);
+        return 0;
 }
 
 /* ARGSUSED */
-void
+int
 input_userauth_banner(int type, u_int32_t seq, void *ctxt)
 {
         char *msg, *raw, *lang;
@@ -542,10 +552,11 @@ input_userauth_banner(int type, u_int32_t seq, void *ctxt)
         }
         free(raw);
         free(lang);
+        return 0;
 }
 
 /* ARGSUSED */
-void
+int
 input_userauth_success(int type, u_int32_t seq, void *ctxt)
 {
         Authctxt *authctxt = ctxt;
@@ -559,9 +570,10 @@ input_userauth_success(int type, u_int32_t seq, void *ctxt)
         free(authctxt->methoddata);
         authctxt->methoddata = NULL;
         authctxt->success = 1;                  /* break out */
+        return 0;
 }
 
-void
+int
 input_userauth_success_unexpected(int type, u_int32_t seq, void *ctxt)
 {
         Authctxt *authctxt = ctxt;
@@ -571,10 +583,11 @@ input_userauth_success_unexpected(int type, u_int32_t seq, void *ctxt)
 
         fatal("Unexpected authentication success during %s.",
             authctxt->method->name);
+        return 0;
 }
 
 /* ARGSUSED */
-void
+int
 input_userauth_failure(int type, u_int32_t seq, void *ctxt)
 {
         Authctxt *authctxt = ctxt;
@@ -597,10 +610,11 @@ input_userauth_failure(int type, u_int32_t seq, void *ctxt)
         debug("Authentications that can continue: %s", authlist);
 
         userauth(authctxt, authlist);
+        return 0;
 }
 
 /* ARGSUSED */
-void
+int
 input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt)
 {
         Authctxt *authctxt = ctxt;
@@ -644,7 +658,9 @@ input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt)
                     key->type, pktype);
                 goto done;
         }
-        fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX);
+        if ((fp = sshkey_fingerprint(key, options.fingerprint_hash,
+            SSH_FP_DEFAULT)) == NULL)
+                goto done;
         debug2("input_userauth_pk_ok: fp %s", fp);
         free(fp);
 
@@ -668,6 +684,7 @@ done:
         /* try another method if we did not send a packet */
         if (sent == 0)
                 userauth(authctxt, NULL);
+        return 0;
 }
 
 #ifdef GSSAPI
@@ -795,7 +812,7 @@ process_gssapi_token(void *ctxt, gss_buffer_t recv_tok)
 }
 
 /* ARGSUSED */
-void
+int
 input_gssapi_response(int type, u_int32_t plen, void *ctxt)
 {
         Authctxt *authctxt = ctxt;
@@ -816,7 +833,7 @@ input_gssapi_response(int type, u_int32_t plen, void *ctxt)
                 free(oidv);
                 debug("Badly encoded mechanism OID received");
                 userauth(authctxt, NULL);
-                return;
+                return 0;
         }
 
         if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
@@ -830,12 +847,13 @@ input_gssapi_response(int type, u_int32_t plen, void *ctxt)
                 /* Start again with next method on list */
                 debug("Trying to start again");
                 userauth(authctxt, NULL);
-                return;
+                return 0;
         }
+        return 0;
 }
 
 /* ARGSUSED */
-void
+int
 input_gssapi_token(int type, u_int32_t plen, void *ctxt)
 {
         Authctxt *authctxt = ctxt;
@@ -858,12 +876,13 @@ input_gssapi_token(int type, u_int32_t plen, void *ctxt)
         if (GSS_ERROR(status)) {
                 /* Start again with the next method in the list */
                 userauth(authctxt, NULL);
-                return;
+                return 0;
         }
+        return 0;
 }
 
 /* ARGSUSED */
-void
+int
 input_gssapi_errtok(int type, u_int32_t plen, void *ctxt)
 {
         Authctxt *authctxt = ctxt;
@@ -890,10 +909,11 @@ input_gssapi_errtok(int type, u_int32_t plen, void *ctxt)
         gss_release_buffer(&ms, &send_tok);
 
         /* Server will be returning a failed packet after this one */
+        return 0;
 }
 
 /* ARGSUSED */
-void
+int
 input_gssapi_error(int type, u_int32_t plen, void *ctxt)
 {
         char *msg;
@@ -909,6 +929,7 @@ input_gssapi_error(int type, u_int32_t plen, void *ctxt)
         debug("Server GSSAPI Error:\n%s", msg);
         free(msg);
         free(lang);
+        return 0;
 }
 
 int
@@ -1005,7 +1026,7 @@ userauth_passwd(Authctxt *authctxt)
  * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
  */
 /* ARGSUSED */
-void
+int
 input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt)
 {
         Authctxt *authctxt = ctxt;
@@ -1046,7 +1067,7 @@ input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt)
                 password = read_passphrase(prompt, RP_ALLOW_EOF);
                 if (password == NULL) {
                         /* bail out */
-                        return;
+                        return 0;
                 }
                 snprintf(prompt, sizeof(prompt),
                     "Retype %.30s@%.128s's new password: ",
@@ -1069,30 +1090,33 @@ input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt)
 
         dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
             &input_userauth_passwd_changereq);
+        return 0;
 }
 
 static int
-identity_sign(Identity *id, u_char **sigp, u_int *lenp,
-    u_char *data, u_int datalen)
+identity_sign(struct identity *id, u_char **sigp, size_t *lenp,
+    const u_char *data, size_t datalen, u_int compat)
 {
         Key *prv;
         int ret;
 
         /* the agent supports this key */
-        if (id->ac)
-                return (ssh_agent_sign(id->ac, id->key, sigp, lenp,
-                    data, datalen));
+        if (id->agent_fd)
+                return ssh_agent_sign(id->agent_fd, id->key, sigp, lenp,
+                    data, datalen, compat);
+
         /*
          * we have already loaded the private key or
          * the private key is stored in external hardware
          */
         if (id->isprivate || (id->key->flags & SSHKEY_FLAG_EXT))
-                return (key_sign(id->key, sigp, lenp, data, datalen));
+                return (sshkey_sign(id->key, sigp, lenp, data, datalen,
+                    compat));
         /* load the private key from the file */
         if ((prv = load_identity_file(id->filename, id->userprovided)) == NULL)
-                return (-1);
-        ret = key_sign(prv, sigp, lenp, data, datalen);
-        key_free(prv);
+                return (-1); /* XXX return decent error code */
+        ret = sshkey_sign(prv, sigp, lenp, data, datalen, compat);
+        sshkey_free(prv);
         return (ret);
 }
 
@@ -1101,13 +1125,16 @@ sign_and_send_pubkey(Authctxt *authctxt, Identity *id)
 {
         Buffer b;
         u_char *blob, *signature;
-        u_int bloblen, slen;
+        u_int bloblen;
+        size_t slen;
         u_int skip = 0;
         int ret = -1;
         int have_sig = 1;
         char *fp;
 
-        fp = key_fingerprint(id->key, SSH_FP_MD5, SSH_FP_HEX);
+        if ((fp = sshkey_fingerprint(id->key, options.fingerprint_hash,
+            SSH_FP_DEFAULT)) == NULL)
+                return 0;
         debug3("sign_and_send_pubkey: %s %s", key_type(id->key), fp);
         free(fp);
 
@@ -1142,8 +1169,8 @@ sign_and_send_pubkey(Authctxt *authctxt, Identity *id)
 
         /* generate signature */
         ret = identity_sign(id, &signature, &slen,
-            buffer_ptr(&b), buffer_len(&b));
-        if (ret == -1) {
+            buffer_ptr(&b), buffer_len(&b), datafellows);
+        if (ret != 0) {
                 free(blob);
                 buffer_free(&b);
                 return 0;
@@ -1218,7 +1245,7 @@ load_identity_file(char *filename, int userprovided)
 {
         Key *private;
         char prompt[300], *passphrase;
-        int perm_ok = 0, quit, i;
+        int r, perm_ok = 0, quit = 0, i;
         struct stat st;
 
         if (stat(filename, &st) < 0) {
@@ -1226,33 +1253,50 @@ load_identity_file(char *filename, int userprovided)
                     filename, strerror(errno));
                 return NULL;
         }
-        private = key_load_private_type(KEY_UNSPEC, filename, "", NULL, &perm_ok);
-        if (!perm_ok) {
-                if (private != NULL)
-                        key_free(private);
-                return NULL;
-        }
-        if (private == NULL) {
-                if (options.batch_mode)
-                        return NULL;
-                snprintf(prompt, sizeof prompt,
-                    "Enter passphrase for key '%.100s': ", filename);
-                for (i = 0; i < options.number_of_password_prompts; i++) {
+        snprintf(prompt, sizeof prompt,
+            "Enter passphrase for key '%.100s': ", filename);
+        for (i = 0; i <= options.number_of_password_prompts; i++) {
+                if (i == 0)
+                        passphrase = "";
+                else {
                         passphrase = read_passphrase(prompt, 0);
-                        if (strcmp(passphrase, "") != 0) {
-                                private = key_load_private_type(KEY_UNSPEC,
-                                    filename, passphrase, NULL, NULL);
-                                quit = 0;
-                        } else {
+                        if (*passphrase == '\0') {
                                 debug2("no passphrase given, try next key");
+                                free(passphrase);
+                                break;
+                        }
+                }
+                switch ((r = sshkey_load_private_type(KEY_UNSPEC, filename,
+                    passphrase, &private, NULL, &perm_ok))) {
+                case 0:
+                        break;
+                case SSH_ERR_KEY_WRONG_PASSPHRASE:
+                        if (options.batch_mode) {
+                                quit = 1;
+                                break;
+                        }
+                        if (i != 0)
+                                debug2("bad passphrase given, try again...");
+                        break;
+                case SSH_ERR_SYSTEM_ERROR:
+                        if (errno == ENOENT) {
+                                debug2("Load key \"%s\": %s",
+                                    filename, ssh_err(r));
                                 quit = 1;
+                                break;
                         }
+                        /* FALLTHROUGH */
+                default:
+                        error("Load key \"%s\": %s", filename, ssh_err(r));
+                        quit = 1;
+                        break;
+                }
+                if (i > 0) {
                         explicit_bzero(passphrase, strlen(passphrase));
                         free(passphrase);
-                        if (private != NULL || quit)
-                                break;
-                        debug2("bad passphrase given, try again...");
                 }
+                if (private != NULL || quit)
+                        break;
         }
         return private;
 }
@@ -1266,12 +1310,12 @@ load_identity_file(char *filename, int userprovided)
 static void
 pubkey_prepare(Authctxt *authctxt)
 {
-        Identity *id, *id2, *tmp;
-        Idlist agent, files, *preferred;
-        Key *key;
-        AuthenticationConnection *ac;
-        char *comment;
-        int i, found;
+        struct identity *id, *id2, *tmp;
+        struct idlist agent, files, *preferred;
+        struct sshkey *key;
+        int agent_fd, i, r, found;
+        size_t j;
+        struct ssh_identitylist *idlist;
 
         TAILQ_INIT(&agent);     /* keys from the agent */
         TAILQ_INIT(&files);     /* keys from the config file */
@@ -1301,7 +1345,7 @@ pubkey_prepare(Authctxt *authctxt)
                         if (id2->key == NULL ||
                             (id2->key->flags & SSHKEY_FLAG_EXT) == 0)
                                 continue;
-                        if (key_equal(id->key, id2->key)) {
+                        if (sshkey_equal(id->key, id2->key)) {
                                 TAILQ_REMOVE(&files, id, next);
                                 TAILQ_INSERT_TAIL(preferred, id, next);
                                 found = 1;
@@ -1316,37 +1360,48 @@ pubkey_prepare(Authctxt *authctxt)
                 }
         }
         /* 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)) {
+        if ((r = ssh_get_authentication_socket(&agent_fd)) != 0) {
+                if (r != SSH_ERR_AGENT_NOT_PRESENT)
+                        debug("%s: ssh_get_authentication_socket: %s",
+                            __func__, ssh_err(r));
+        } else if ((r = ssh_fetch_identitylist(agent_fd, 2, &idlist)) != 0) {
+                if (r != SSH_ERR_AGENT_NO_IDENTITIES)
+                        debug("%s: ssh_fetch_identitylist: %s",
+                            __func__, ssh_err(r));
+        } else {
+                for (j = 0; j < idlist->nkeys; j++) {
                         found = 0;
                         TAILQ_FOREACH(id, &files, next) {
-                                /* agent keys from the config file are preferred */
-                                if (key_equal(key, id->key)) {
-                                        key_free(key);
-                                        free(comment);
+                                /*
+                                 * agent keys from the config file are
+                                 * preferred
+                                 */
+                                if (sshkey_equal(idlist->keys[j], id->key)) {
                                         TAILQ_REMOVE(&files, id, next);
                                         TAILQ_INSERT_TAIL(preferred, id, next);
-                                        id->ac = ac;
+                                        id->agent_fd = agent_fd;
                                         found = 1;
                                         break;
                                 }
                         }
                         if (!found && !options.identities_only) {
                                 id = xcalloc(1, sizeof(*id));
-                                id->key = key;
-                                id->filename = comment;
-                                id->ac = ac;
+                                /* XXX "steals" key/comment from idlist */
+                                id->key = idlist->keys[j];
+                                id->filename = idlist->comments[j];
+                                idlist->keys[j] = NULL;
+                                idlist->comments[j] = NULL;
+                                id->agent_fd = agent_fd;
                                 TAILQ_INSERT_TAIL(&agent, id, next);
                         }
                 }
+                ssh_free_identitylist(idlist);
                 /* 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;
+                authctxt->agent_fd = agent_fd;
         }
         /* append remaining keys from the config file */
         for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) {
@@ -1364,13 +1419,13 @@ pubkey_cleanup(Authctxt *authctxt)
 {
         Identity *id;
 
-        if (authctxt->agent != NULL)
-                ssh_close_authentication_connection(authctxt->agent);
+        if (authctxt->agent_fd != -1)
+                ssh_close_authentication_socket(authctxt->agent_fd);
         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);
+                        sshkey_free(id->key);
                 free(id->filename);
                 free(id);
         }
@@ -1462,7 +1517,7 @@ userauth_kbdint(Authctxt *authctxt)
 /*
  * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
  */
-void
+int
 input_userauth_info_req(int type, u_int32_t seq, void *ctxt)
 {
         Authctxt *authctxt = ctxt;
@@ -1514,81 +1569,120 @@ input_userauth_info_req(int type, u_int32_t seq, void *ctxt)
 
         packet_add_padding(64);
         packet_send();
+        return 0;
 }
 
 static int
-ssh_keysign(Key *key, u_char **sigp, u_int *lenp,
-    u_char *data, u_int datalen)
+ssh_keysign(struct sshkey *key, u_char **sigp, size_t *lenp,
+    const u_char *data, size_t datalen)
 {
-        Buffer b;
+        struct sshbuf *b;
         struct stat st;
         pid_t pid;
-        int to[2], from[2], status, version = 2;
+        int i, r, to[2], from[2], status, sock = packet_get_connection_in();
+        u_char rversion = 0, version = 2;
+        void (*osigchld)(int);
 
-        debug2("ssh_keysign called");
+        *sigp = NULL;
+        *lenp = 0;
 
         if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) {
-                error("ssh_keysign: not installed: %s", strerror(errno));
+                error("%s: not installed: %s", __func__, strerror(errno));
+                return -1;
+        }
+        if (fflush(stdout) != 0) {
+                error("%s: fflush: %s", __func__, strerror(errno));
                 return -1;
         }
-        if (fflush(stdout) != 0)
-                error("ssh_keysign: fflush: %s", strerror(errno));
         if (pipe(to) < 0) {
-                error("ssh_keysign: pipe: %s", strerror(errno));
+                error("%s: pipe: %s", __func__, strerror(errno));
                 return -1;
         }
         if (pipe(from) < 0) {
-                error("ssh_keysign: pipe: %s", strerror(errno));
+                error("%s: pipe: %s", __func__, strerror(errno));
                 return -1;
         }
         if ((pid = fork()) < 0) {
-                error("ssh_keysign: fork: %s", strerror(errno));
+                error("%s: fork: %s", __func__, strerror(errno));
                 return -1;
         }
+        osigchld = signal(SIGCHLD, SIG_DFL);
         if (pid == 0) {
                 /* keep the socket on exec */
-                fcntl(packet_get_connection_in(), F_SETFD, 0);
+                fcntl(sock, F_SETFD, 0);
                 permanently_drop_suid(getuid());
                 close(from[0]);
                 if (dup2(from[1], STDOUT_FILENO) < 0)
-                        fatal("ssh_keysign: dup2: %s", strerror(errno));
+                        fatal("%s: dup2: %s", __func__, strerror(errno));
                 close(to[1]);
                 if (dup2(to[0], STDIN_FILENO) < 0)
-                        fatal("ssh_keysign: dup2: %s", strerror(errno));
+                        fatal("%s: dup2: %s", __func__, strerror(errno));
                 close(from[1]);
                 close(to[0]);
+                /* Close everything but stdio and the socket */
+                for (i = STDERR_FILENO + 1; i < sock; i++)
+                        close(i);
+                closefrom(sock + 1);
+                debug3("%s: [child] pid=%ld, exec %s",
+                    __func__, (long)getpid(), _PATH_SSH_KEY_SIGN);
                 execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *) 0);
-                fatal("ssh_keysign: exec(%s): %s", _PATH_SSH_KEY_SIGN,
+                fatal("%s: exec(%s): %s", __func__, _PATH_SSH_KEY_SIGN,
                     strerror(errno));
         }
         close(from[1]);
         close(to[0]);
 
-        buffer_init(&b);
-        buffer_put_int(&b, packet_get_connection_in()); /* send # of socket */
-        buffer_put_string(&b, data, datalen);
-        if (ssh_msg_send(to[1], version, &b) == -1)
-                fatal("ssh_keysign: couldn't send request");
-
-        if (ssh_msg_recv(from[0], &b) < 0) {
-                error("ssh_keysign: no reply");
-                buffer_free(&b);
-                return -1;
-        }
+        if ((b = sshbuf_new()) == NULL)
+                fatal("%s: sshbuf_new failed", __func__);
+        /* send # of sock, data to be signed */
+        if ((r = sshbuf_put_u32(b, sock) != 0) ||
+            (r = sshbuf_put_string(b, data, datalen)) != 0)
+                fatal("%s: buffer error: %s", __func__, ssh_err(r));
+        if (ssh_msg_send(to[1], version, b) == -1)
+                fatal("%s: couldn't send request", __func__);
+        sshbuf_reset(b);
+        r = ssh_msg_recv(from[0], b);
         close(from[0]);
         close(to[1]);
+        if (r < 0) {
+                error("%s: no reply", __func__);
+                goto fail;
+        }
 
-        while (waitpid(pid, &status, 0) < 0)
-                if (errno != EINTR)
-                        break;
-
-        if (buffer_get_char(&b) != version) {
-                error("ssh_keysign: bad version");
-                buffer_free(&b);
+        errno = 0;
+        while (waitpid(pid, &status, 0) < 0) {
+                if (errno != EINTR) {
+                        error("%s: waitpid %ld: %s",
+                            __func__, (long)pid, strerror(errno));
+                        goto fail;
+                }
+        }
+        if (!WIFEXITED(status)) {
+                error("%s: exited abnormally", __func__);
+                goto fail;
+        }
+        if (WEXITSTATUS(status) != 0) {
+                error("%s: exited with status %d",
+                    __func__, WEXITSTATUS(status));
+                goto fail;
+        }
+        if ((r = sshbuf_get_u8(b, &rversion)) != 0) {
+                error("%s: buffer error: %s", __func__, ssh_err(r));
+                goto fail;
+        }
+        if (rversion != version) {
+                error("%s: bad version", __func__);
+                goto fail;
+        }
+        if ((r = sshbuf_get_string(b, sigp, lenp)) != 0) {
+                error("%s: buffer error: %s", __func__, ssh_err(r));
+ fail:
+                signal(SIGCHLD, osigchld);
+                sshbuf_free(b);
                 return -1;
         }
-        *sigp = buffer_get_string(&b, lenp);
-        buffer_free(&b);
+        signal(SIGCHLD, osigchld);
+        sshbuf_free(b);
 
         return 0;
 }
@@ -1596,94 +1690,149 @@ ssh_keysign(Key *key, u_char **sigp, u_int *lenp,
 int
 userauth_hostbased(Authctxt *authctxt)
 {
-        Key *private = NULL;
-        Sensitive *sensitive = authctxt->sensitive;
-        Buffer b;
-        u_char *signature, *blob;
-        char *chost, *pkalg, *p;
+        struct ssh *ssh = active_state;
+        struct sshkey *private = NULL;
+        struct sshbuf *b = NULL;
         const char *service;
-        u_int blen, slen;
-        int ok, i, found = 0;
-
-        /* check for a useful key */
-        for (i = 0; i < sensitive->nkeys; i++) {
-                private = sensitive->keys[i];
-                if (private && private->type != KEY_RSA1) {
-                        found = 1;
+        u_char *sig = NULL, *keyblob = NULL;
+        char *fp = NULL, *chost = NULL, *lname = NULL;
+        size_t siglen = 0, keylen = 0;
+        int i, r, success = 0;
+
+        if (authctxt->ktypes == NULL) {
+                authctxt->oktypes = xstrdup(options.hostbased_key_types);
+                authctxt->ktypes = authctxt->oktypes;
+        }
+
+        /*
+         * Work through each listed type pattern in HostbasedKeyTypes,
+         * trying each hostkey that matches the type in turn.
+         */
+        for (;;) {
+                if (authctxt->active_ktype == NULL)
+                        authctxt->active_ktype = strsep(&authctxt->ktypes, ",");
+                if (authctxt->active_ktype == NULL ||
+                    *authctxt->active_ktype == '\0')
+                        break;
+                debug3("%s: trying key type %s", __func__,
+                    authctxt->active_ktype);
+
+                /* check for a useful key */
+                private = NULL;
+                for (i = 0; i < authctxt->sensitive->nkeys; i++) {
+                        if (authctxt->sensitive->keys[i] == NULL ||
+                            authctxt->sensitive->keys[i]->type == KEY_RSA1 ||
+                            authctxt->sensitive->keys[i]->type == KEY_UNSPEC)
+                                continue;
+                        if (match_pattern_list(
+                            sshkey_ssh_name(authctxt->sensitive->keys[i]),
+                            authctxt->active_ktype,
+                            strlen(authctxt->active_ktype), 0) != 1)
+                                continue;
                         /* we take and free the key */
-                        sensitive->keys[i] = NULL;
+                        private = authctxt->sensitive->keys[i];
+                        authctxt->sensitive->keys[i] = NULL;
                         break;
                 }
+                /* Found one */
+                if (private != NULL)
+                        break;
+                /* No more keys of this type; advance */
+                authctxt->active_ktype = NULL;
         }
-        if (!found) {
+        if (private == NULL) {
+                free(authctxt->oktypes);
+                authctxt->oktypes = authctxt->ktypes = NULL;
+                authctxt->active_ktype = NULL;
                 debug("No more client hostkeys for hostbased authentication.");
-                return 0;
+                goto out;
         }
-        if (key_to_blob(private, &blob, &blen) == 0) {
-                key_free(private);
-                return 0;
+
+        if ((fp = sshkey_fingerprint(private, options.fingerprint_hash,
+            SSH_FP_DEFAULT)) == NULL) {
+                error("%s: sshkey_fingerprint failed", __func__);
+                goto out;
         }
+        debug("%s: trying hostkey %s %s",
+            __func__, sshkey_ssh_name(private), fp);
+
         /* figure out a name for the client host */
-        p = get_local_name(packet_get_connection_in());
-        if (p == NULL) {
-                error("userauth_hostbased: cannot get local ipaddr/name");
-                key_free(private);
-                free(blob);
-                return 0;
+        if ((lname = get_local_name(packet_get_connection_in())) == NULL) {
+                error("%s: cannot get local ipaddr/name", __func__);
+                goto out;
         }
-        xasprintf(&chost, "%s.", p);
-        debug2("userauth_hostbased: chost %s", chost);
-        free(p);
+
+        /* XXX sshbuf_put_stringf? */
+        xasprintf(&chost, "%s.", lname);
+        debug2("%s: chost %s", __func__, chost);
 
         service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
             authctxt->service;
-        pkalg = xstrdup(key_ssh_name(private));
-        buffer_init(&b);
+
         /* construct data */
-        buffer_put_string(&b, session_id2, session_id2_len);
-        buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
-        buffer_put_cstring(&b, authctxt->server_user);
-        buffer_put_cstring(&b, service);
-        buffer_put_cstring(&b, authctxt->method->name);
-        buffer_put_cstring(&b, pkalg);
-        buffer_put_string(&b, blob, blen);
-        buffer_put_cstring(&b, chost);
-        buffer_put_cstring(&b, authctxt->local_user);
+        if ((b = sshbuf_new()) == NULL) {
+                error("%s: sshbuf_new failed", __func__);
+                goto out;
+        }
+        if ((r = sshkey_to_blob(private, &keyblob, &keylen)) != 0) {
+                error("%s: sshkey_to_blob: %s", __func__, ssh_err(r));
+                goto out;
+        }
+        if ((r = sshbuf_put_string(b, session_id2, session_id2_len)) != 0 ||
+            (r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
+            (r = sshbuf_put_cstring(b, authctxt->server_user)) != 0 ||
+            (r = sshbuf_put_cstring(b, service)) != 0 ||
+            (r = sshbuf_put_cstring(b, authctxt->method->name)) != 0 ||
+            (r = sshbuf_put_cstring(b, key_ssh_name(private))) != 0 ||
+            (r = sshbuf_put_string(b, keyblob, keylen)) != 0 ||
+            (r = sshbuf_put_cstring(b, chost)) != 0 ||
+            (r = sshbuf_put_cstring(b, authctxt->local_user)) != 0) {
+                error("%s: buffer error: %s", __func__, ssh_err(r));
+                goto out;
+        }
+
 #ifdef DEBUG_PK
-        buffer_dump(&b);
+        sshbuf_dump(b, stderr);
 #endif
-        if (sensitive->external_keysign)
-                ok = ssh_keysign(private, &signature, &slen,
-                    buffer_ptr(&b), buffer_len(&b));
-        else
-                ok = key_sign(private, &signature, &slen,
-                    buffer_ptr(&b), buffer_len(&b));
-        key_free(private);
-        buffer_free(&b);
-        if (ok != 0) {
-                error("key_sign failed");
-                free(chost);
-                free(pkalg);
-                free(blob);
-                return 0;
+        if (authctxt->sensitive->external_keysign)
+                r = ssh_keysign(private, &sig, &siglen,
+                    sshbuf_ptr(b), sshbuf_len(b));
+        else if ((r = sshkey_sign(private, &sig, &siglen,
+            sshbuf_ptr(b), sshbuf_len(b), datafellows)) != 0)
+                debug("%s: sshkey_sign: %s", __func__, ssh_err(r));
+        if (r != 0) {
+                error("sign using hostkey %s %s failed",
+                    sshkey_ssh_name(private), fp);
+                goto out;
         }
-        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_cstring(pkalg);
-        packet_put_string(blob, blen);
-        packet_put_cstring(chost);
-        packet_put_cstring(authctxt->local_user);
-        packet_put_string(signature, slen);
-        explicit_bzero(signature, slen);
-        free(signature);
+        if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
+            (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
+            (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
+            (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
+            (r = sshpkt_put_cstring(ssh, key_ssh_name(private))) != 0 ||
+            (r = sshpkt_put_string(ssh, keyblob, keylen)) != 0 ||
+            (r = sshpkt_put_cstring(ssh, chost)) != 0 ||
+            (r = sshpkt_put_cstring(ssh, authctxt->local_user)) != 0 ||
+            (r = sshpkt_put_string(ssh, sig, siglen)) != 0 ||
+            (r = sshpkt_send(ssh)) != 0) {
+                error("%s: packet error: %s", __func__, ssh_err(r));
+                goto out;
+        }
+        success = 1;
+
+ out:
+        if (sig != NULL) {
+                explicit_bzero(sig, siglen);
+                free(sig);
+        }
+        free(keyblob);
+        free(lname);
+        free(fp);
         free(chost);
-        free(pkalg);
-        free(blob);
+        sshkey_free(private);
+        sshbuf_free(b);
 
-        packet_send();
-        return 1;
+        return success;
 }
 
 /* find auth method */