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-rw-r--r--sshconnect2.c2396
1 files changed, 2396 insertions, 0 deletions
diff --git a/sshconnect2.c b/sshconnect2.c
new file mode 100644
index 0000000..58fe98d
--- /dev/null
+++ b/sshconnect2.c
@@ -0,0 +1,2396 @@
+/* $OpenBSD: sshconnect2.c,v 1.361 2022/09/17 10:33:18 djm Exp $ */
+/*
+ * Copyright (c) 2000 Markus Friedl. All rights reserved.
+ * Copyright (c) 2008 Damien Miller. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "includes.h"
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/wait.h>
+#include <sys/stat.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <netdb.h>
+#include <pwd.h>
+#include <signal.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdarg.h>
+#include <unistd.h>
+#if defined(HAVE_STRNVIS) && defined(HAVE_VIS_H) && !defined(BROKEN_STRNVIS)
+#include <vis.h>
+#endif
+
+#include "openbsd-compat/sys-queue.h"
+
+#include "xmalloc.h"
+#include "ssh.h"
+#include "ssh2.h"
+#include "sshbuf.h"
+#include "packet.h"
+#include "compat.h"
+#include "cipher.h"
+#include "sshkey.h"
+#include "kex.h"
+#include "myproposal.h"
+#include "sshconnect.h"
+#include "authfile.h"
+#include "dh.h"
+#include "authfd.h"
+#include "log.h"
+#include "misc.h"
+#include "readconf.h"
+#include "match.h"
+#include "dispatch.h"
+#include "canohost.h"
+#include "msg.h"
+#include "pathnames.h"
+#include "uidswap.h"
+#include "hostfile.h"
+#include "ssherr.h"
+#include "utf8.h"
+#include "ssh-sk.h"
+#include "sk-api.h"
+
+#ifdef GSSAPI
+#include "ssh-gss.h"
+#endif
+
+/* import */
+extern char *client_version_string;
+extern char *server_version_string;
+extern Options options;
+
+/*
+ * SSH2 key exchange
+ */
+
+static char *xxx_host;
+static struct sockaddr *xxx_hostaddr;
+static const struct ssh_conn_info *xxx_conn_info;
+
+static int
+verify_host_key_callback(struct sshkey *hostkey, struct ssh *ssh)
+{
+ int r;
+
+ if ((r = sshkey_check_rsa_length(hostkey,
+ options.required_rsa_size)) != 0)
+ fatal_r(r, "Bad server host key");
+ if (verify_host_key(xxx_host, xxx_hostaddr, hostkey,
+ xxx_conn_info) == -1)
+ fatal("Host key verification failed.");
+ return 0;
+}
+
+/* Returns the first item from a comma-separated algorithm list */
+static char *
+first_alg(const char *algs)
+{
+ char *ret, *cp;
+
+ ret = xstrdup(algs);
+ if ((cp = strchr(ret, ',')) != NULL)
+ *cp = '\0';
+ return ret;
+}
+
+static char *
+order_hostkeyalgs(char *host, struct sockaddr *hostaddr, u_short port,
+ const struct ssh_conn_info *cinfo)
+{
+ char *oavail = NULL, *avail = NULL, *first = NULL, *last = NULL;
+ char *alg = NULL, *hostname = NULL, *ret = NULL, *best = NULL;
+ size_t maxlen;
+ struct hostkeys *hostkeys = NULL;
+ int ktype;
+ u_int i;
+
+ /* Find all hostkeys for this hostname */
+ get_hostfile_hostname_ipaddr(host, hostaddr, port, &hostname, NULL);
+ hostkeys = init_hostkeys();
+ for (i = 0; i < options.num_user_hostfiles; i++)
+ load_hostkeys(hostkeys, hostname, options.user_hostfiles[i], 0);
+ for (i = 0; i < options.num_system_hostfiles; i++) {
+ load_hostkeys(hostkeys, hostname,
+ options.system_hostfiles[i], 0);
+ }
+ if (options.known_hosts_command != NULL) {
+ load_hostkeys_command(hostkeys, options.known_hosts_command,
+ "ORDER", cinfo, NULL, host);
+ }
+ /*
+ * If a plain public key exists that matches the type of the best
+ * preference HostkeyAlgorithms, then use the whole list as is.
+ * Note that we ignore whether the best preference algorithm is a
+ * certificate type, as sshconnect.c will downgrade certs to
+ * plain keys if necessary.
+ */
+ best = first_alg(options.hostkeyalgorithms);
+ if (lookup_key_in_hostkeys_by_type(hostkeys,
+ sshkey_type_plain(sshkey_type_from_name(best)),
+ sshkey_ecdsa_nid_from_name(best), NULL)) {
+ debug3_f("have matching best-preference key type %s, "
+ "using HostkeyAlgorithms verbatim", best);
+ ret = xstrdup(options.hostkeyalgorithms);
+ goto out;
+ }
+
+ /*
+ * Otherwise, prefer the host key algorithms that match known keys
+ * while keeping the ordering of HostkeyAlgorithms as much as possible.
+ */
+ oavail = avail = xstrdup(options.hostkeyalgorithms);
+ maxlen = strlen(avail) + 1;
+ first = xmalloc(maxlen);
+ last = xmalloc(maxlen);
+ *first = *last = '\0';
+
+#define ALG_APPEND(to, from) \
+ do { \
+ if (*to != '\0') \
+ strlcat(to, ",", maxlen); \
+ strlcat(to, from, maxlen); \
+ } while (0)
+
+ while ((alg = strsep(&avail, ",")) && *alg != '\0') {
+ if ((ktype = sshkey_type_from_name(alg)) == KEY_UNSPEC)
+ fatal_f("unknown alg %s", alg);
+ /*
+ * If we have a @cert-authority marker in known_hosts then
+ * prefer all certificate algorithms.
+ */
+ if (sshkey_type_is_cert(ktype) &&
+ lookup_marker_in_hostkeys(hostkeys, MRK_CA)) {
+ ALG_APPEND(first, alg);
+ continue;
+ }
+ /* If the key appears in known_hosts then prefer it */
+ if (lookup_key_in_hostkeys_by_type(hostkeys,
+ sshkey_type_plain(ktype),
+ sshkey_ecdsa_nid_from_name(alg), NULL)) {
+ ALG_APPEND(first, alg);
+ continue;
+ }
+ /* Otherwise, put it last */
+ ALG_APPEND(last, alg);
+ }
+#undef ALG_APPEND
+ xasprintf(&ret, "%s%s%s", first,
+ (*first == '\0' || *last == '\0') ? "" : ",", last);
+ if (*first != '\0')
+ debug3_f("prefer hostkeyalgs: %s", first);
+ else
+ debug3_f("no algorithms matched; accept original");
+ out:
+ free(best);
+ free(first);
+ free(last);
+ free(hostname);
+ free(oavail);
+ free_hostkeys(hostkeys);
+
+ return ret;
+}
+
+void
+ssh_kex2(struct ssh *ssh, char *host, struct sockaddr *hostaddr, u_short port,
+ const struct ssh_conn_info *cinfo)
+{
+ char *myproposal[PROPOSAL_MAX] = { KEX_CLIENT };
+ char *s, *all_key;
+ char *prop_kex = NULL, *prop_enc = NULL, *prop_hostkey = NULL;
+ int r, use_known_hosts_order = 0;
+
+ xxx_host = host;
+ xxx_hostaddr = hostaddr;
+ xxx_conn_info = cinfo;
+
+ /*
+ * If the user has not specified HostkeyAlgorithms, or has only
+ * appended or removed algorithms from that list then prefer algorithms
+ * that are in the list that are supported by known_hosts keys.
+ */
+ if (options.hostkeyalgorithms == NULL ||
+ options.hostkeyalgorithms[0] == '-' ||
+ options.hostkeyalgorithms[0] == '+')
+ use_known_hosts_order = 1;
+
+ /* Expand or fill in HostkeyAlgorithms */
+ all_key = sshkey_alg_list(0, 0, 1, ',');
+ if ((r = kex_assemble_names(&options.hostkeyalgorithms,
+ kex_default_pk_alg(), all_key)) != 0)
+ fatal_fr(r, "kex_assemble_namelist");
+ free(all_key);
+
+ if ((s = kex_names_cat(options.kex_algorithms, "ext-info-c")) == NULL)
+ fatal_f("kex_names_cat");
+ myproposal[PROPOSAL_KEX_ALGS] = prop_kex = compat_kex_proposal(ssh, s);
+ myproposal[PROPOSAL_ENC_ALGS_CTOS] =
+ myproposal[PROPOSAL_ENC_ALGS_STOC] = prop_enc =
+ compat_cipher_proposal(ssh, options.ciphers);
+ myproposal[PROPOSAL_COMP_ALGS_CTOS] =
+ myproposal[PROPOSAL_COMP_ALGS_STOC] =
+ (char *)compression_alg_list(options.compression);
+ myproposal[PROPOSAL_MAC_ALGS_CTOS] =
+ myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
+ if (use_known_hosts_order) {
+ /* Query known_hosts and prefer algorithms that appear there */
+ myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = prop_hostkey =
+ compat_pkalg_proposal(ssh,
+ order_hostkeyalgs(host, hostaddr, port, cinfo));
+ } else {
+ /* Use specified HostkeyAlgorithms exactly */
+ myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = prop_hostkey =
+ compat_pkalg_proposal(ssh, options.hostkeyalgorithms);
+ }
+
+ if (options.rekey_limit || options.rekey_interval)
+ ssh_packet_set_rekey_limits(ssh, options.rekey_limit,
+ options.rekey_interval);
+
+ /* start key exchange */
+ if ((r = kex_setup(ssh, myproposal)) != 0)
+ fatal_r(r, "kex_setup");
+#ifdef WITH_OPENSSL
+ ssh->kex->kex[KEX_DH_GRP1_SHA1] = kex_gen_client;
+ ssh->kex->kex[KEX_DH_GRP14_SHA1] = kex_gen_client;
+ ssh->kex->kex[KEX_DH_GRP14_SHA256] = kex_gen_client;
+ ssh->kex->kex[KEX_DH_GRP16_SHA512] = kex_gen_client;
+ ssh->kex->kex[KEX_DH_GRP18_SHA512] = kex_gen_client;
+ ssh->kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
+ ssh->kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
+# ifdef OPENSSL_HAS_ECC
+ ssh->kex->kex[KEX_ECDH_SHA2] = kex_gen_client;
+# endif
+#endif
+ ssh->kex->kex[KEX_C25519_SHA256] = kex_gen_client;
+ ssh->kex->kex[KEX_KEM_SNTRUP761X25519_SHA512] = kex_gen_client;
+ ssh->kex->verify_host_key=&verify_host_key_callback;
+
+ ssh_dispatch_run_fatal(ssh, DISPATCH_BLOCK, &ssh->kex->done);
+
+ /* remove ext-info from the KEX proposals for rekeying */
+ myproposal[PROPOSAL_KEX_ALGS] =
+ compat_kex_proposal(ssh, options.kex_algorithms);
+ if ((r = kex_prop2buf(ssh->kex->my, myproposal)) != 0)
+ fatal_r(r, "kex_prop2buf");
+
+#ifdef DEBUG_KEXDH
+ /* send 1st encrypted/maced/compressed message */
+ if ((r = sshpkt_start(ssh, SSH2_MSG_IGNORE)) != 0 ||
+ (r = sshpkt_put_cstring(ssh, "markus")) != 0 ||
+ (r = sshpkt_send(ssh)) != 0 ||
+ (r = ssh_packet_write_wait(ssh)) != 0)
+ fatal_fr(r, "send packet");
+#endif
+ /* Free only parts of proposal that were dynamically allocated here. */
+ free(prop_kex);
+ free(prop_enc);
+ free(prop_hostkey);
+}
+
+/*
+ * Authenticate user
+ */
+
+typedef struct cauthctxt Authctxt;
+typedef struct cauthmethod Authmethod;
+typedef struct identity Identity;
+typedef struct idlist Idlist;
+
+struct identity {
+ TAILQ_ENTRY(identity) next;
+ 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 */
+ int userprovided;
+};
+TAILQ_HEAD(idlist, identity);
+
+struct cauthctxt {
+ const char *server_user;
+ const char *local_user;
+ const char *host;
+ const char *service;
+ struct cauthmethod *method;
+ sig_atomic_t success;
+ char *authlist;
+#ifdef GSSAPI
+ /* gssapi */
+ gss_OID_set gss_supported_mechs;
+ u_int mech_tried;
+#endif
+ /* pubkey */
+ struct idlist keys;
+ int agent_fd;
+ /* hostbased */
+ Sensitive *sensitive;
+ char *oktypes, *ktypes;
+ const char *active_ktype;
+ /* kbd-interactive */
+ int info_req_seen;
+ int attempt_kbdint;
+ /* password */
+ int attempt_passwd;
+ /* generic */
+ void *methoddata;
+};
+
+struct cauthmethod {
+ char *name; /* string to compare against server's list */
+ int (*userauth)(struct ssh *ssh);
+ void (*cleanup)(struct ssh *ssh);
+ int *enabled; /* flag in option struct that enables method */
+ int *batch_flag; /* flag in option struct that disables method */
+};
+
+static int input_userauth_service_accept(int, u_int32_t, struct ssh *);
+static int input_userauth_ext_info(int, u_int32_t, struct ssh *);
+static int input_userauth_success(int, u_int32_t, struct ssh *);
+static int input_userauth_failure(int, u_int32_t, struct ssh *);
+static int input_userauth_banner(int, u_int32_t, struct ssh *);
+static int input_userauth_error(int, u_int32_t, struct ssh *);
+static int input_userauth_info_req(int, u_int32_t, struct ssh *);
+static int input_userauth_pk_ok(int, u_int32_t, struct ssh *);
+static int input_userauth_passwd_changereq(int, u_int32_t, struct ssh *);
+
+static int userauth_none(struct ssh *);
+static int userauth_pubkey(struct ssh *);
+static int userauth_passwd(struct ssh *);
+static int userauth_kbdint(struct ssh *);
+static int userauth_hostbased(struct ssh *);
+
+#ifdef GSSAPI
+static int userauth_gssapi(struct ssh *);
+static void userauth_gssapi_cleanup(struct ssh *);
+static int input_gssapi_response(int type, u_int32_t, struct ssh *);
+static int input_gssapi_token(int type, u_int32_t, struct ssh *);
+static int input_gssapi_error(int, u_int32_t, struct ssh *);
+static int input_gssapi_errtok(int, u_int32_t, struct ssh *);
+#endif
+
+void userauth(struct ssh *, char *);
+
+static void pubkey_cleanup(struct ssh *);
+static int sign_and_send_pubkey(struct ssh *ssh, Identity *);
+static void pubkey_prepare(struct ssh *, Authctxt *);
+static void pubkey_reset(Authctxt *);
+static struct sshkey *load_identity_file(Identity *);
+
+static Authmethod *authmethod_get(char *authlist);
+static Authmethod *authmethod_lookup(const char *name);
+static char *authmethods_get(void);
+
+Authmethod authmethods[] = {
+#ifdef GSSAPI
+ {"gssapi-with-mic",
+ userauth_gssapi,
+ userauth_gssapi_cleanup,
+ &options.gss_authentication,
+ NULL},
+#endif
+ {"hostbased",
+ userauth_hostbased,
+ NULL,
+ &options.hostbased_authentication,
+ NULL},
+ {"publickey",
+ userauth_pubkey,
+ NULL,
+ &options.pubkey_authentication,
+ NULL},
+ {"keyboard-interactive",
+ userauth_kbdint,
+ NULL,
+ &options.kbd_interactive_authentication,
+ &options.batch_mode},
+ {"password",
+ userauth_passwd,
+ NULL,
+ &options.password_authentication,
+ &options.batch_mode},
+ {"none",
+ userauth_none,
+ NULL,
+ NULL,
+ NULL},
+ {NULL, NULL, NULL, NULL, NULL}
+};
+
+void
+ssh_userauth2(struct ssh *ssh, const char *local_user,
+ const char *server_user, char *host, Sensitive *sensitive)
+{
+ Authctxt authctxt;
+ int r;
+
+ if (options.preferred_authentications == NULL)
+ options.preferred_authentications = authmethods_get();
+
+ /* setup authentication context */
+ memset(&authctxt, 0, sizeof(authctxt));
+ authctxt.server_user = server_user;
+ authctxt.local_user = local_user;
+ authctxt.host = host;
+ authctxt.service = "ssh-connection"; /* service name */
+ authctxt.success = 0;
+ authctxt.method = authmethod_lookup("none");
+ authctxt.authlist = NULL;
+ authctxt.methoddata = NULL;
+ authctxt.sensitive = sensitive;
+ authctxt.active_ktype = authctxt.oktypes = authctxt.ktypes = NULL;
+ authctxt.info_req_seen = 0;
+ authctxt.attempt_kbdint = 0;
+ authctxt.attempt_passwd = 0;
+#if GSSAPI
+ authctxt.gss_supported_mechs = NULL;
+ authctxt.mech_tried = 0;
+#endif
+ authctxt.agent_fd = -1;
+ pubkey_prepare(ssh, &authctxt);
+ if (authctxt.method == NULL) {
+ fatal_f("internal error: cannot send userauth none request");
+ }
+
+ if ((r = sshpkt_start(ssh, SSH2_MSG_SERVICE_REQUEST)) != 0 ||
+ (r = sshpkt_put_cstring(ssh, "ssh-userauth")) != 0 ||
+ (r = sshpkt_send(ssh)) != 0)
+ fatal_fr(r, "send packet");
+
+ ssh->authctxt = &authctxt;
+ ssh_dispatch_init(ssh, &input_userauth_error);
+ ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &input_userauth_ext_info);
+ ssh_dispatch_set(ssh, SSH2_MSG_SERVICE_ACCEPT, &input_userauth_service_accept);
+ ssh_dispatch_run_fatal(ssh, DISPATCH_BLOCK, &authctxt.success); /* loop until success */
+ pubkey_cleanup(ssh);
+ ssh->authctxt = NULL;
+
+ ssh_dispatch_range(ssh, SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
+
+ if (!authctxt.success)
+ fatal("Authentication failed.");
+ if (ssh_packet_connection_is_on_socket(ssh)) {
+ verbose("Authenticated to %s ([%s]:%d) using \"%s\".", host,
+ ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
+ authctxt.method->name);
+ } else {
+ verbose("Authenticated to %s (via proxy) using \"%s\".", host,
+ authctxt.method->name);
+ }
+}
+
+/* ARGSUSED */
+static int
+input_userauth_service_accept(int type, u_int32_t seq, struct ssh *ssh)
+{
+ int r;
+
+ if (ssh_packet_remaining(ssh) > 0) {
+ char *reply;
+
+ if ((r = sshpkt_get_cstring(ssh, &reply, NULL)) != 0)
+ goto out;
+ debug2("service_accept: %s", reply);
+ free(reply);
+ } else {
+ debug2("buggy server: service_accept w/o service");
+ }
+ if ((r = sshpkt_get_end(ssh)) != 0)
+ goto out;
+ debug("SSH2_MSG_SERVICE_ACCEPT received");
+
+ /* initial userauth request */
+ userauth_none(ssh);
+
+ ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &input_userauth_error);
+ ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
+ ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
+ ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
+ r = 0;
+ out:
+ return r;
+}
+
+/* ARGSUSED */
+static int
+input_userauth_ext_info(int type, u_int32_t seqnr, struct ssh *ssh)
+{
+ return kex_input_ext_info(type, seqnr, ssh);
+}
+
+void
+userauth(struct ssh *ssh, char *authlist)
+{
+ Authctxt *authctxt = (Authctxt *)ssh->authctxt;
+
+ if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
+ authctxt->method->cleanup(ssh);
+
+ free(authctxt->methoddata);
+ authctxt->methoddata = NULL;
+ if (authlist == NULL) {
+ authlist = authctxt->authlist;
+ } else {
+ free(authctxt->authlist);
+ authctxt->authlist = authlist;
+ }
+ for (;;) {
+ Authmethod *method = authmethod_get(authlist);
+ if (method == NULL)
+ fatal("%s@%s: Permission denied (%s).",
+ authctxt->server_user, authctxt->host, authlist);
+ authctxt->method = method;
+
+ /* reset the per method handler */
+ ssh_dispatch_range(ssh, SSH2_MSG_USERAUTH_PER_METHOD_MIN,
+ SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
+
+ /* and try new method */
+ if (method->userauth(ssh) != 0) {
+ debug2("we sent a %s packet, wait for reply", method->name);
+ break;
+ } else {
+ debug2("we did not send a packet, disable method");
+ method->enabled = NULL;
+ }
+ }
+}
+
+/* ARGSUSED */
+static int
+input_userauth_error(int type, u_int32_t seq, struct ssh *ssh)
+{
+ fatal_f("bad message during authentication: type %d", type);
+ return 0;
+}
+
+/* ARGSUSED */
+static int
+input_userauth_banner(int type, u_int32_t seq, struct ssh *ssh)
+{
+ char *msg = NULL;
+ size_t len;
+ int r;
+
+ debug3_f("entering");
+ if ((r = sshpkt_get_cstring(ssh, &msg, &len)) != 0 ||
+ (r = sshpkt_get_cstring(ssh, NULL, NULL)) != 0)
+ goto out;
+ if (len > 0 && options.log_level >= SYSLOG_LEVEL_INFO)
+ fmprintf(stderr, "%s", msg);
+ r = 0;
+ out:
+ free(msg);
+ return r;
+}
+
+/* ARGSUSED */
+static int
+input_userauth_success(int type, u_int32_t seq, struct ssh *ssh)
+{
+ Authctxt *authctxt = ssh->authctxt;
+
+ if (authctxt == NULL)
+ fatal_f("no authentication context");
+ free(authctxt->authlist);
+ authctxt->authlist = NULL;
+ if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
+ authctxt->method->cleanup(ssh);
+ free(authctxt->methoddata);
+ authctxt->methoddata = NULL;
+ authctxt->success = 1; /* break out */
+ return 0;
+}
+
+#if 0
+static int
+input_userauth_success_unexpected(int type, u_int32_t seq, struct ssh *ssh)
+{
+ Authctxt *authctxt = ssh->authctxt;
+
+ if (authctxt == NULL)
+ fatal_f("no authentication context");
+
+ fatal("Unexpected authentication success during %s.",
+ authctxt->method->name);
+ return 0;
+}
+#endif
+
+/* ARGSUSED */
+static int
+input_userauth_failure(int type, u_int32_t seq, struct ssh *ssh)
+{
+ Authctxt *authctxt = ssh->authctxt;
+ char *authlist = NULL;
+ u_char partial;
+
+ if (authctxt == NULL)
+ fatal("input_userauth_failure: no authentication context");
+
+ if (sshpkt_get_cstring(ssh, &authlist, NULL) != 0 ||
+ sshpkt_get_u8(ssh, &partial) != 0 ||
+ sshpkt_get_end(ssh) != 0)
+ goto out;
+
+ if (partial != 0) {
+ verbose("Authenticated using \"%s\" with partial success.",
+ authctxt->method->name);
+ /* reset state */
+ pubkey_reset(authctxt);
+ }
+ debug("Authentications that can continue: %s", authlist);
+
+ userauth(ssh, authlist);
+ authlist = NULL;
+ out:
+ free(authlist);
+ return 0;
+}
+
+/*
+ * Format an identity for logging including filename, key type, fingerprint
+ * and location (agent, etc.). Caller must free.
+ */
+static char *
+format_identity(Identity *id)
+{
+ char *fp = NULL, *ret = NULL;
+ const char *note = "";
+
+ if (id->key != NULL) {
+ fp = sshkey_fingerprint(id->key, options.fingerprint_hash,
+ SSH_FP_DEFAULT);
+ }
+ if (id->key) {
+ if ((id->key->flags & SSHKEY_FLAG_EXT) != 0)
+ note = " token";
+ else if (sshkey_is_sk(id->key))
+ note = " authenticator";
+ }
+ xasprintf(&ret, "%s %s%s%s%s%s%s",
+ id->filename,
+ id->key ? sshkey_type(id->key) : "", id->key ? " " : "",
+ fp ? fp : "",
+ id->userprovided ? " explicit" : "", note,
+ id->agent_fd != -1 ? " agent" : "");
+ free(fp);
+ return ret;
+}
+
+/* ARGSUSED */
+static int
+input_userauth_pk_ok(int type, u_int32_t seq, struct ssh *ssh)
+{
+ Authctxt *authctxt = ssh->authctxt;
+ struct sshkey *key = NULL;
+ Identity *id = NULL;
+ int pktype, found = 0, sent = 0;
+ size_t blen;
+ char *pkalg = NULL, *fp = NULL, *ident = NULL;
+ u_char *pkblob = NULL;
+ int r;
+
+ if (authctxt == NULL)
+ fatal("input_userauth_pk_ok: no authentication context");
+
+ if ((r = sshpkt_get_cstring(ssh, &pkalg, NULL)) != 0 ||
+ (r = sshpkt_get_string(ssh, &pkblob, &blen)) != 0 ||
+ (r = sshpkt_get_end(ssh)) != 0)
+ goto done;
+
+ if ((pktype = sshkey_type_from_name(pkalg)) == KEY_UNSPEC) {
+ debug_f("server sent unknown pkalg %s", pkalg);
+ goto done;
+ }
+ if ((r = sshkey_from_blob(pkblob, blen, &key)) != 0) {
+ debug_r(r, "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;
+ }
+
+ /*
+ * search keys in the reverse order, because last candidate has been
+ * moved to the end of the queue. this also avoids confusion by
+ * duplicate keys
+ */
+ TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) {
+ if (sshkey_equal(key, id->key)) {
+ found = 1;
+ break;
+ }
+ }
+ if (!found || id == NULL) {
+ fp = sshkey_fingerprint(key, options.fingerprint_hash,
+ SSH_FP_DEFAULT);
+ error_f("server replied with unknown key: %s %s",
+ sshkey_type(key), fp == NULL ? "<ERROR>" : fp);
+ goto done;
+ }
+ ident = format_identity(id);
+ debug("Server accepts key: %s", ident);
+ sent = sign_and_send_pubkey(ssh, id);
+ r = 0;
+ done:
+ sshkey_free(key);
+ free(ident);
+ free(fp);
+ free(pkalg);
+ free(pkblob);
+
+ /* try another method if we did not send a packet */
+ if (r == 0 && sent == 0)
+ userauth(ssh, NULL);
+ return r;
+}
+
+#ifdef GSSAPI
+static int
+userauth_gssapi(struct ssh *ssh)
+{
+ Authctxt *authctxt = (Authctxt *)ssh->authctxt;
+ Gssctxt *gssctxt = NULL;
+ OM_uint32 min;
+ int r, ok = 0;
+ gss_OID mech = NULL;
+
+ /* Try one GSSAPI method at a time, rather than sending them all at
+ * once. */
+
+ if (authctxt->gss_supported_mechs == NULL)
+ gss_indicate_mechs(&min, &authctxt->gss_supported_mechs);
+
+ /* Check to see whether the mechanism is usable before we offer it */
+ while (authctxt->mech_tried < authctxt->gss_supported_mechs->count &&
+ !ok) {
+ mech = &authctxt->gss_supported_mechs->
+ elements[authctxt->mech_tried];
+ /* My DER encoding requires length<128 */
+ if (mech->length < 128 && ssh_gssapi_check_mechanism(&gssctxt,
+ mech, authctxt->host)) {
+ ok = 1; /* Mechanism works */
+ } else {
+ authctxt->mech_tried++;
+ }
+ }
+
+ if (!ok || mech == NULL)
+ return 0;
+
+ authctxt->methoddata=(void *)gssctxt;
+
+ 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_u32(ssh, 1)) != 0 ||
+ (r = sshpkt_put_u32(ssh, (mech->length) + 2)) != 0 ||
+ (r = sshpkt_put_u8(ssh, SSH_GSS_OIDTYPE)) != 0 ||
+ (r = sshpkt_put_u8(ssh, mech->length)) != 0 ||
+ (r = sshpkt_put(ssh, mech->elements, mech->length)) != 0 ||
+ (r = sshpkt_send(ssh)) != 0)
+ fatal_fr(r, "send packet");
+
+ ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
+ ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
+ ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
+ ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
+
+ authctxt->mech_tried++; /* Move along to next candidate */
+
+ return 1;
+}
+
+static void
+userauth_gssapi_cleanup(struct ssh *ssh)
+{
+ Authctxt *authctxt = (Authctxt *)ssh->authctxt;
+ Gssctxt *gssctxt = (Gssctxt *)authctxt->methoddata;
+
+ ssh_gssapi_delete_ctx(&gssctxt);
+ authctxt->methoddata = NULL;
+
+ free(authctxt->gss_supported_mechs);
+ authctxt->gss_supported_mechs = NULL;
+}
+
+static OM_uint32
+process_gssapi_token(struct ssh *ssh, gss_buffer_t recv_tok)
+{
+ Authctxt *authctxt = ssh->authctxt;
+ Gssctxt *gssctxt = authctxt->methoddata;
+ gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
+ gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
+ gss_buffer_desc gssbuf;
+ OM_uint32 status, ms, flags;
+ int r;
+
+ status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
+ recv_tok, &send_tok, &flags);
+
+ if (send_tok.length > 0) {
+ u_char type = GSS_ERROR(status) ?
+ SSH2_MSG_USERAUTH_GSSAPI_ERRTOK :
+ SSH2_MSG_USERAUTH_GSSAPI_TOKEN;
+
+ if ((r = sshpkt_start(ssh, type)) != 0 ||
+ (r = sshpkt_put_string(ssh, send_tok.value,
+ send_tok.length)) != 0 ||
+ (r = sshpkt_send(ssh)) != 0)
+ fatal_fr(r, "send %u packet", type);
+
+ gss_release_buffer(&ms, &send_tok);
+ }
+
+ if (status == GSS_S_COMPLETE) {
+ /* send either complete or MIC, depending on mechanism */
+ if (!(flags & GSS_C_INTEG_FLAG)) {
+ if ((r = sshpkt_start(ssh,
+ SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE)) != 0 ||
+ (r = sshpkt_send(ssh)) != 0)
+ fatal_fr(r, "send completion");
+ } else {
+ struct sshbuf *b;
+
+ if ((b = sshbuf_new()) == NULL)
+ fatal_f("sshbuf_new failed");
+ ssh_gssapi_buildmic(b, authctxt->server_user,
+ authctxt->service, "gssapi-with-mic",
+ ssh->kex->session_id);
+
+ if ((gssbuf.value = sshbuf_mutable_ptr(b)) == NULL)
+ fatal_f("sshbuf_mutable_ptr failed");
+ gssbuf.length = sshbuf_len(b);
+
+ status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
+
+ if (!GSS_ERROR(status)) {
+ if ((r = sshpkt_start(ssh,
+ SSH2_MSG_USERAUTH_GSSAPI_MIC)) != 0 ||
+ (r = sshpkt_put_string(ssh, mic.value,
+ mic.length)) != 0 ||
+ (r = sshpkt_send(ssh)) != 0)
+ fatal_fr(r, "send MIC");
+ }
+
+ sshbuf_free(b);
+ gss_release_buffer(&ms, &mic);
+ }
+ }
+
+ return status;
+}
+
+/* ARGSUSED */
+static int
+input_gssapi_response(int type, u_int32_t plen, struct ssh *ssh)
+{
+ Authctxt *authctxt = ssh->authctxt;
+ Gssctxt *gssctxt;
+ size_t oidlen;
+ u_char *oidv = NULL;
+ int r;
+
+ if (authctxt == NULL)
+ fatal("input_gssapi_response: no authentication context");
+ gssctxt = authctxt->methoddata;
+
+ /* Setup our OID */
+ if ((r = sshpkt_get_string(ssh, &oidv, &oidlen)) != 0)
+ goto done;
+
+ if (oidlen <= 2 ||
+ oidv[0] != SSH_GSS_OIDTYPE ||
+ oidv[1] != oidlen - 2) {
+ debug("Badly encoded mechanism OID received");
+ userauth(ssh, NULL);
+ goto ok;
+ }
+
+ if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
+ fatal("Server returned different OID than expected");
+
+ if ((r = sshpkt_get_end(ssh)) != 0)
+ goto done;
+
+ if (GSS_ERROR(process_gssapi_token(ssh, GSS_C_NO_BUFFER))) {
+ /* Start again with next method on list */
+ debug("Trying to start again");
+ userauth(ssh, NULL);
+ goto ok;
+ }
+ ok:
+ r = 0;
+ done:
+ free(oidv);
+ return r;
+}
+
+/* ARGSUSED */
+static int
+input_gssapi_token(int type, u_int32_t plen, struct ssh *ssh)
+{
+ Authctxt *authctxt = ssh->authctxt;
+ gss_buffer_desc recv_tok;
+ u_char *p = NULL;
+ size_t len;
+ OM_uint32 status;
+ int r;
+
+ if (authctxt == NULL)
+ fatal("input_gssapi_response: no authentication context");
+
+ if ((r = sshpkt_get_string(ssh, &p, &len)) != 0 ||
+ (r = sshpkt_get_end(ssh)) != 0)
+ goto out;
+
+ recv_tok.value = p;
+ recv_tok.length = len;
+ status = process_gssapi_token(ssh, &recv_tok);
+
+ /* Start again with the next method in the list */
+ if (GSS_ERROR(status)) {
+ userauth(ssh, NULL);
+ /* ok */
+ }
+ r = 0;
+ out:
+ free(p);
+ return r;
+}
+
+/* ARGSUSED */
+static int
+input_gssapi_errtok(int type, u_int32_t plen, struct ssh *ssh)
+{
+ Authctxt *authctxt = ssh->authctxt;
+ Gssctxt *gssctxt;
+ gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
+ gss_buffer_desc recv_tok;
+ OM_uint32 ms;
+ u_char *p = NULL;
+ size_t len;
+ int r;
+
+ if (authctxt == NULL)
+ fatal("input_gssapi_response: no authentication context");
+ gssctxt = authctxt->methoddata;
+
+ if ((r = sshpkt_get_string(ssh, &p, &len)) != 0 ||
+ (r = sshpkt_get_end(ssh)) != 0) {
+ free(p);
+ return r;
+ }
+
+ /* Stick it into GSSAPI and see what it says */
+ recv_tok.value = p;
+ recv_tok.length = len;
+ (void)ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
+ &recv_tok, &send_tok, NULL);
+ free(p);
+ gss_release_buffer(&ms, &send_tok);
+
+ /* Server will be returning a failed packet after this one */
+ return 0;
+}
+
+/* ARGSUSED */
+static int
+input_gssapi_error(int type, u_int32_t plen, struct ssh *ssh)
+{
+ char *msg = NULL;
+ char *lang = NULL;
+ int r;
+
+ if ((r = sshpkt_get_u32(ssh, NULL)) != 0 || /* maj */
+ (r = sshpkt_get_u32(ssh, NULL)) != 0 || /* min */
+ (r = sshpkt_get_cstring(ssh, &msg, NULL)) != 0 ||
+ (r = sshpkt_get_cstring(ssh, &lang, NULL)) != 0)
+ goto out;
+ r = sshpkt_get_end(ssh);
+ debug("Server GSSAPI Error:\n%s", msg);
+ out:
+ free(msg);
+ free(lang);
+ return r;
+}
+#endif /* GSSAPI */
+
+static int
+userauth_none(struct ssh *ssh)
+{
+ Authctxt *authctxt = (Authctxt *)ssh->authctxt;
+ int r;
+
+ /* initial userauth request */
+ 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_send(ssh)) != 0)
+ fatal_fr(r, "send packet");
+ return 1;
+}
+
+static int
+userauth_passwd(struct ssh *ssh)
+{
+ Authctxt *authctxt = (Authctxt *)ssh->authctxt;
+ char *password, *prompt = NULL;
+ const char *host = options.host_key_alias ? options.host_key_alias :
+ authctxt->host;
+ int r;
+
+ if (authctxt->attempt_passwd++ >= options.number_of_password_prompts)
+ return 0;
+
+ if (authctxt->attempt_passwd != 1)
+ error("Permission denied, please try again.");
+
+ xasprintf(&prompt, "%s@%s's password: ", authctxt->server_user, host);
+ password = read_passphrase(prompt, 0);
+ 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_u8(ssh, 0)) != 0 ||
+ (r = sshpkt_put_cstring(ssh, password)) != 0 ||
+ (r = sshpkt_add_padding(ssh, 64)) != 0 ||
+ (r = sshpkt_send(ssh)) != 0)
+ fatal_fr(r, "send packet");
+
+ free(prompt);
+ if (password != NULL)
+ freezero(password, strlen(password));
+
+ ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
+ &input_userauth_passwd_changereq);
+
+ return 1;
+}
+
+/*
+ * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
+ */
+/* ARGSUSED */
+static int
+input_userauth_passwd_changereq(int type, u_int32_t seqnr, struct ssh *ssh)
+{
+ Authctxt *authctxt = ssh->authctxt;
+ char *info = NULL, *lang = NULL, *password = NULL, *retype = NULL;
+ char prompt[256];
+ const char *host;
+ int r;
+
+ debug2("input_userauth_passwd_changereq");
+
+ if (authctxt == NULL)
+ fatal("input_userauth_passwd_changereq: "
+ "no authentication context");
+ host = options.host_key_alias ? options.host_key_alias : authctxt->host;
+
+ if ((r = sshpkt_get_cstring(ssh, &info, NULL)) != 0 ||
+ (r = sshpkt_get_cstring(ssh, &lang, NULL)) != 0)
+ goto out;
+ if (strlen(info) > 0)
+ logit("%s", info);
+ 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_u8(ssh, 1)) != 0) /* additional info */
+ goto out;
+
+ snprintf(prompt, sizeof(prompt),
+ "Enter %.30s@%.128s's old password: ",
+ authctxt->server_user, host);
+ password = read_passphrase(prompt, 0);
+ if ((r = sshpkt_put_cstring(ssh, password)) != 0)
+ goto out;
+
+ freezero(password, strlen(password));
+ password = NULL;
+ while (password == NULL) {
+ snprintf(prompt, sizeof(prompt),
+ "Enter %.30s@%.128s's new password: ",
+ authctxt->server_user, host);
+ password = read_passphrase(prompt, RP_ALLOW_EOF);
+ if (password == NULL) {
+ /* bail out */
+ r = 0;
+ goto out;
+ }
+ snprintf(prompt, sizeof(prompt),
+ "Retype %.30s@%.128s's new password: ",
+ authctxt->server_user, host);
+ retype = read_passphrase(prompt, 0);
+ if (strcmp(password, retype) != 0) {
+ freezero(password, strlen(password));
+ logit("Mismatch; try again, EOF to quit.");
+ password = NULL;
+ }
+ freezero(retype, strlen(retype));
+ }
+ if ((r = sshpkt_put_cstring(ssh, password)) != 0 ||
+ (r = sshpkt_add_padding(ssh, 64)) != 0 ||
+ (r = sshpkt_send(ssh)) != 0)
+ goto out;
+
+ ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
+ &input_userauth_passwd_changereq);
+ r = 0;
+ out:
+ if (password)
+ freezero(password, strlen(password));
+ free(info);
+ free(lang);
+ return r;
+}
+
+/*
+ * Select an algorithm for publickey signatures.
+ * Returns algorithm (caller must free) or NULL if no mutual algorithm found.
+ *
+ * Call with ssh==NULL to ignore server-sig-algs extension list and
+ * only attempt with the key's base signature type.
+ */
+static char *
+key_sig_algorithm(struct ssh *ssh, const struct sshkey *key)
+{
+ char *allowed, *oallowed, *cp, *tmp, *alg = NULL;
+ const char *server_sig_algs;
+
+ /*
+ * The signature algorithm will only differ from the key algorithm
+ * for RSA keys/certs and when the server advertises support for
+ * newer (SHA2) algorithms.
+ */
+ if (ssh == NULL || ssh->kex->server_sig_algs == NULL ||
+ (key->type != KEY_RSA && key->type != KEY_RSA_CERT) ||
+ (key->type == KEY_RSA_CERT && (ssh->compat & SSH_BUG_SIGTYPE))) {
+ /* Filter base key signature alg against our configuration */
+ return match_list(sshkey_ssh_name(key),
+ options.pubkey_accepted_algos, NULL);
+ }
+
+ /*
+ * Workaround OpenSSH 7.4 bug: this version supports RSA/SHA-2 but
+ * fails to advertise it via SSH2_MSG_EXT_INFO.
+ */
+ server_sig_algs = ssh->kex->server_sig_algs;
+ if (key->type == KEY_RSA && (ssh->compat & SSH_BUG_SIGTYPE74))
+ server_sig_algs = "rsa-sha2-256,rsa-sha2-512";
+
+ /*
+ * For RSA keys/certs, since these might have a different sig type:
+ * find the first entry in PubkeyAcceptedAlgorithms of the right type
+ * that also appears in the supported signature algorithms list from
+ * the server.
+ */
+ oallowed = allowed = xstrdup(options.pubkey_accepted_algos);
+ while ((cp = strsep(&allowed, ",")) != NULL) {
+ if (sshkey_type_from_name(cp) != key->type)
+ continue;
+ tmp = match_list(sshkey_sigalg_by_name(cp),
+ server_sig_algs, NULL);
+ if (tmp != NULL)
+ alg = xstrdup(cp);
+ free(tmp);
+ if (alg != NULL)
+ break;
+ }
+ free(oallowed);
+ return alg;
+}
+
+static int
+identity_sign(struct identity *id, u_char **sigp, size_t *lenp,
+ const u_char *data, size_t datalen, u_int compat, const char *alg)
+{
+ struct sshkey *sign_key = NULL, *prv = NULL;
+ int is_agent = 0, retried = 0, r = SSH_ERR_INTERNAL_ERROR;
+ struct notifier_ctx *notifier = NULL;
+ char *fp = NULL, *pin = NULL, *prompt = NULL;
+
+ *sigp = NULL;
+ *lenp = 0;
+
+ /* The agent supports this key. */
+ if (id->key != NULL && id->agent_fd != -1) {
+ return ssh_agent_sign(id->agent_fd, id->key, sigp, lenp,
+ data, datalen, alg, compat);
+ }
+
+ /*
+ * We have already loaded the private key or the private key is
+ * stored in external hardware.
+ */
+ if (id->key != NULL &&
+ (id->isprivate || (id->key->flags & SSHKEY_FLAG_EXT))) {
+ sign_key = id->key;
+ is_agent = 1;
+ } else {
+ /* Load the private key from the file. */
+ if ((prv = load_identity_file(id)) == NULL)
+ return SSH_ERR_KEY_NOT_FOUND;
+ if (id->key != NULL && !sshkey_equal_public(prv, id->key)) {
+ error_f("private key %s contents do not match public",
+ id->filename);
+ r = SSH_ERR_KEY_NOT_FOUND;
+ goto out;
+ }
+ sign_key = prv;
+ }
+ retry_pin:
+ /* Prompt for touch for non-agent FIDO keys that request UP */
+ if (!is_agent && sshkey_is_sk(sign_key) &&
+ (sign_key->sk_flags & SSH_SK_USER_PRESENCE_REQD)) {
+ /* XXX should batch mode just skip these? */
+ if ((fp = sshkey_fingerprint(sign_key,
+ options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL)
+ fatal_f("fingerprint failed");
+ notifier = notify_start(options.batch_mode,
+ "Confirm user presence for key %s %s",
+ sshkey_type(sign_key), fp);
+ free(fp);
+ }
+ if ((r = sshkey_sign(sign_key, sigp, lenp, data, datalen,
+ alg, options.sk_provider, pin, compat)) != 0) {
+ debug_fr(r, "sshkey_sign");
+ if (!retried && pin == NULL && !is_agent &&
+ sshkey_is_sk(sign_key) &&
+ r == SSH_ERR_KEY_WRONG_PASSPHRASE) {
+ notify_complete(notifier, NULL);
+ notifier = NULL;
+ xasprintf(&prompt, "Enter PIN for %s key %s: ",
+ sshkey_type(sign_key), id->filename);
+ pin = read_passphrase(prompt, 0);
+ retried = 1;
+ goto retry_pin;
+ }
+ goto out;
+ }
+
+ /*
+ * PKCS#11 tokens may not support all signature algorithms,
+ * so check what we get back.
+ */
+ if ((r = sshkey_check_sigtype(*sigp, *lenp, alg)) != 0) {
+ debug_fr(r, "sshkey_check_sigtype");
+ goto out;
+ }
+ /* success */
+ r = 0;
+ out:
+ free(prompt);
+ if (pin != NULL)
+ freezero(pin, strlen(pin));
+ notify_complete(notifier, r == 0 ? "User presence confirmed" : NULL);
+ sshkey_free(prv);
+ return r;
+}
+
+static int
+id_filename_matches(Identity *id, Identity *private_id)
+{
+ static const char * const suffixes[] = { ".pub", "-cert.pub", NULL };
+ size_t len = strlen(id->filename), plen = strlen(private_id->filename);
+ size_t i, slen;
+
+ if (strcmp(id->filename, private_id->filename) == 0)
+ return 1;
+ for (i = 0; suffixes[i]; i++) {
+ slen = strlen(suffixes[i]);
+ if (len > slen && plen == len - slen &&
+ strcmp(id->filename + (len - slen), suffixes[i]) == 0 &&
+ memcmp(id->filename, private_id->filename, plen) == 0)
+ return 1;
+ }
+ return 0;
+}
+
+static int
+sign_and_send_pubkey(struct ssh *ssh, Identity *id)
+{
+ Authctxt *authctxt = (Authctxt *)ssh->authctxt;
+ struct sshbuf *b = NULL;
+ Identity *private_id, *sign_id = NULL;
+ u_char *signature = NULL;
+ size_t slen = 0, skip = 0;
+ int r, fallback_sigtype, sent = 0;
+ char *alg = NULL, *fp = NULL;
+ const char *loc = "", *method = "publickey";
+ int hostbound = 0;
+
+ /* prefer host-bound pubkey signatures if supported by server */
+ if ((ssh->kex->flags & KEX_HAS_PUBKEY_HOSTBOUND) != 0 &&
+ (options.pubkey_authentication & SSH_PUBKEY_AUTH_HBOUND) != 0) {
+ hostbound = 1;
+ method = "publickey-hostbound-v00@openssh.com";
+ }
+
+ if ((fp = sshkey_fingerprint(id->key, options.fingerprint_hash,
+ SSH_FP_DEFAULT)) == NULL)
+ return 0;
+
+ debug3_f("using %s with %s %s", method, sshkey_type(id->key), fp);
+
+ /*
+ * If the key is an certificate, try to find a matching private key
+ * and use it to complete the signature.
+ * If no such private key exists, fall back to trying the certificate
+ * key itself in case it has a private half already loaded.
+ * This will try to set sign_id to the private key that will perform
+ * the signature.
+ */
+ if (sshkey_is_cert(id->key)) {
+ TAILQ_FOREACH(private_id, &authctxt->keys, next) {
+ if (sshkey_equal_public(id->key, private_id->key) &&
+ id->key->type != private_id->key->type) {
+ sign_id = private_id;
+ break;
+ }
+ }
+ /*
+ * Exact key matches are preferred, but also allow
+ * filename matches for non-PKCS#11/agent keys that
+ * didn't load public keys. This supports the case
+ * of keeping just a private key file and public
+ * certificate on disk.
+ */
+ if (sign_id == NULL &&
+ !id->isprivate && id->agent_fd == -1 &&
+ (id->key->flags & SSHKEY_FLAG_EXT) == 0) {
+ TAILQ_FOREACH(private_id, &authctxt->keys, next) {
+ if (private_id->key == NULL &&
+ id_filename_matches(id, private_id)) {
+ sign_id = private_id;
+ break;
+ }
+ }
+ }
+ if (sign_id != NULL) {
+ debug2_f("using private key \"%s\"%s for "
+ "certificate", sign_id->filename,
+ sign_id->agent_fd != -1 ? " from agent" : "");
+ } else {
+ debug_f("no separate private key for certificate "
+ "\"%s\"", id->filename);
+ }
+ }
+
+ /*
+ * If the above didn't select another identity to do the signing
+ * then default to the one we started with.
+ */
+ if (sign_id == NULL)
+ sign_id = id;
+
+ /* assemble and sign data */
+ for (fallback_sigtype = 0; fallback_sigtype <= 1; fallback_sigtype++) {
+ free(alg);
+ slen = 0;
+ signature = NULL;
+ if ((alg = key_sig_algorithm(fallback_sigtype ? NULL : ssh,
+ id->key)) == NULL) {
+ error_f("no mutual signature supported");
+ goto out;
+ }
+ debug3_f("signing using %s %s", alg, fp);
+
+ sshbuf_free(b);
+ if ((b = sshbuf_new()) == NULL)
+ fatal_f("sshbuf_new failed");
+ if (ssh->compat & SSH_OLD_SESSIONID) {
+ if ((r = sshbuf_putb(b, ssh->kex->session_id)) != 0)
+ fatal_fr(r, "sshbuf_putb");
+ } else {
+ if ((r = sshbuf_put_stringb(b,
+ ssh->kex->session_id)) != 0)
+ fatal_fr(r, "sshbuf_put_stringb");
+ }
+ skip = sshbuf_len(b);
+ if ((r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
+ (r = sshbuf_put_cstring(b, authctxt->server_user)) != 0 ||
+ (r = sshbuf_put_cstring(b, authctxt->service)) != 0 ||
+ (r = sshbuf_put_cstring(b, method)) != 0 ||
+ (r = sshbuf_put_u8(b, 1)) != 0 ||
+ (r = sshbuf_put_cstring(b, alg)) != 0 ||
+ (r = sshkey_puts(id->key, b)) != 0) {
+ fatal_fr(r, "assemble signed data");
+ }
+ if (hostbound) {
+ if (ssh->kex->initial_hostkey == NULL) {
+ fatal_f("internal error: initial hostkey "
+ "not recorded");
+ }
+ if ((r = sshkey_puts(ssh->kex->initial_hostkey, b)) != 0)
+ fatal_fr(r, "assemble %s hostkey", method);
+ }
+ /* generate signature */
+ r = identity_sign(sign_id, &signature, &slen,
+ sshbuf_ptr(b), sshbuf_len(b), ssh->compat, alg);
+ if (r == 0)
+ break;
+ else if (r == SSH_ERR_KEY_NOT_FOUND)
+ goto out; /* soft failure */
+ else if (r == SSH_ERR_SIGN_ALG_UNSUPPORTED &&
+ !fallback_sigtype) {
+ if (sign_id->agent_fd != -1)
+ loc = "agent ";
+ else if ((sign_id->key->flags & SSHKEY_FLAG_EXT) != 0)
+ loc = "token ";
+ logit("%skey %s %s returned incorrect signature type",
+ loc, sshkey_type(id->key), fp);
+ continue;
+ }
+ error_fr(r, "signing failed for %s \"%s\"%s",
+ sshkey_type(sign_id->key), sign_id->filename,
+ id->agent_fd != -1 ? " from agent" : "");
+ goto out;
+ }
+ if (slen == 0 || signature == NULL) /* shouldn't happen */
+ fatal_f("no signature");
+
+ /* append signature */
+ if ((r = sshbuf_put_string(b, signature, slen)) != 0)
+ fatal_fr(r, "append signature");
+
+#ifdef DEBUG_PK
+ sshbuf_dump(b, stderr);
+#endif
+ /* skip session id and packet type */
+ if ((r = sshbuf_consume(b, skip + 1)) != 0)
+ fatal_fr(r, "consume");
+
+ /* put remaining data from buffer into packet */
+ if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
+ (r = sshpkt_putb(ssh, b)) != 0 ||
+ (r = sshpkt_send(ssh)) != 0)
+ fatal_fr(r, "enqueue request");
+
+ /* success */
+ sent = 1;
+
+ out:
+ free(fp);
+ free(alg);
+ sshbuf_free(b);
+ freezero(signature, slen);
+ return sent;
+}
+
+static int
+send_pubkey_test(struct ssh *ssh, Identity *id)
+{
+ Authctxt *authctxt = (Authctxt *)ssh->authctxt;
+ u_char *blob = NULL;
+ char *alg = NULL;
+ size_t bloblen;
+ u_int have_sig = 0;
+ int sent = 0, r;
+
+ if ((alg = key_sig_algorithm(ssh, id->key)) == NULL) {
+ debug_f("no mutual signature algorithm");
+ goto out;
+ }
+
+ if ((r = sshkey_to_blob(id->key, &blob, &bloblen)) != 0) {
+ /* we cannot handle this key */
+ debug3_f("cannot handle key");
+ goto out;
+ }
+ /* register callback for USERAUTH_PK_OK message */
+ ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
+
+ 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_u8(ssh, have_sig)) != 0 ||
+ (r = sshpkt_put_cstring(ssh, alg)) != 0 ||
+ (r = sshpkt_put_string(ssh, blob, bloblen)) != 0 ||
+ (r = sshpkt_send(ssh)) != 0)
+ fatal_fr(r, "send packet");
+ sent = 1;
+
+ out:
+ free(alg);
+ free(blob);
+ return sent;
+}
+
+static struct sshkey *
+load_identity_file(Identity *id)
+{
+ struct sshkey *private = NULL;
+ char prompt[300], *passphrase, *comment;
+ int r, quit = 0, i;
+ struct stat st;
+
+ if (stat(id->filename, &st) == -1) {
+ do_log2(id->userprovided ?
+ SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_DEBUG3,
+ "no such identity: %s: %s", id->filename, strerror(errno));
+ return NULL;
+ }
+ snprintf(prompt, sizeof prompt,
+ "Enter passphrase for key '%.100s': ", id->filename);
+ for (i = 0; i <= options.number_of_password_prompts; i++) {
+ if (i == 0)
+ passphrase = "";
+ else {
+ passphrase = read_passphrase(prompt, 0);
+ if (*passphrase == '\0') {
+ debug2("no passphrase given, try next key");
+ free(passphrase);
+ break;
+ }
+ }
+ switch ((r = sshkey_load_private_type(KEY_UNSPEC, id->filename,
+ passphrase, &private, &comment))) {
+ 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_r(r, "Load key \"%s\"", id->filename);
+ quit = 1;
+ break;
+ }
+ /* FALLTHROUGH */
+ default:
+ error_r(r, "Load key \"%s\"", id->filename);
+ quit = 1;
+ break;
+ }
+ if (private != NULL && sshkey_is_sk(private) &&
+ options.sk_provider == NULL) {
+ debug("key \"%s\" is an authenticator-hosted key, "
+ "but no provider specified", id->filename);
+ sshkey_free(private);
+ private = NULL;
+ quit = 1;
+ }
+ if (!quit && (r = sshkey_check_rsa_length(private,
+ options.required_rsa_size)) != 0) {
+ debug_fr(r, "Skipping key %s", id->filename);
+ sshkey_free(private);
+ private = NULL;
+ quit = 1;
+ }
+ if (!quit && private != NULL && id->agent_fd == -1 &&
+ !(id->key && id->isprivate))
+ maybe_add_key_to_agent(id->filename, private, comment,
+ passphrase);
+ if (i > 0)
+ freezero(passphrase, strlen(passphrase));
+ free(comment);
+ if (private != NULL || quit)
+ break;
+ }
+ return private;
+}
+
+static int
+key_type_allowed_by_config(struct sshkey *key)
+{
+ if (match_pattern_list(sshkey_ssh_name(key),
+ options.pubkey_accepted_algos, 0) == 1)
+ return 1;
+
+ /* RSA keys/certs might be allowed by alternate signature types */
+ switch (key->type) {
+ case KEY_RSA:
+ if (match_pattern_list("rsa-sha2-512",
+ options.pubkey_accepted_algos, 0) == 1)
+ return 1;
+ if (match_pattern_list("rsa-sha2-256",
+ options.pubkey_accepted_algos, 0) == 1)
+ return 1;
+ break;
+ case KEY_RSA_CERT:
+ if (match_pattern_list("rsa-sha2-512-cert-v01@openssh.com",
+ options.pubkey_accepted_algos, 0) == 1)
+ return 1;
+ if (match_pattern_list("rsa-sha2-256-cert-v01@openssh.com",
+ options.pubkey_accepted_algos, 0) == 1)
+ return 1;
+ break;
+ }
+ return 0;
+}
+
+/* obtain a list of keys from the agent */
+static int
+get_agent_identities(struct ssh *ssh, int *agent_fdp,
+ struct ssh_identitylist **idlistp)
+{
+ int r, agent_fd;
+ struct ssh_identitylist *idlist;
+
+ if ((r = ssh_get_authentication_socket(&agent_fd)) != 0) {
+ if (r != SSH_ERR_AGENT_NOT_PRESENT)
+ debug_fr(r, "ssh_get_authentication_socket");
+ return r;
+ }
+ if ((r = ssh_agent_bind_hostkey(agent_fd, ssh->kex->initial_hostkey,
+ ssh->kex->session_id, ssh->kex->initial_sig, 0)) == 0)
+ debug_f("bound agent to hostkey");
+ else
+ debug2_fr(r, "ssh_agent_bind_hostkey");
+
+ if ((r = ssh_fetch_identitylist(agent_fd, &idlist)) != 0) {
+ debug_fr(r, "ssh_fetch_identitylist");
+ close(agent_fd);
+ return r;
+ }
+ /* success */
+ *agent_fdp = agent_fd;
+ *idlistp = idlist;
+ debug_f("agent returned %zu keys", idlist->nkeys);
+ return 0;
+}
+
+/*
+ * try keys in the following order:
+ * 1. certificates listed in the config file
+ * 2. other input certificates
+ * 3. agent keys that are found in the config file
+ * 4. other agent keys
+ * 5. keys that are only listed in the config file
+ */
+static void
+pubkey_prepare(struct ssh *ssh, Authctxt *authctxt)
+{
+ struct identity *id, *id2, *tmp;
+ struct idlist agent, files, *preferred;
+ struct sshkey *key;
+ int agent_fd = -1, i, r, found;
+ size_t j;
+ struct ssh_identitylist *idlist;
+ char *ident;
+
+ 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 and PKCS#11 */
+ for (i = 0; i < options.num_identity_files; i++) {
+ key = options.identity_keys[i];
+ if (key && key->cert &&
+ key->cert->type != SSH2_CERT_TYPE_USER) {
+ debug_f("ignoring certificate %s: not a user "
+ "certificate", options.identity_files[i]);
+ continue;
+ }
+ if (key && sshkey_is_sk(key) && options.sk_provider == NULL) {
+ debug_f("ignoring authenticator-hosted key %s as no "
+ "SecurityKeyProvider has been specified",
+ options.identity_files[i]);
+ continue;
+ }
+ options.identity_keys[i] = NULL;
+ id = xcalloc(1, sizeof(*id));
+ id->agent_fd = -1;
+ id->key = key;
+ id->filename = xstrdup(options.identity_files[i]);
+ id->userprovided = options.identity_file_userprovided[i];
+ TAILQ_INSERT_TAIL(&files, id, next);
+ }
+ /* list of certificates specified by user */
+ for (i = 0; i < options.num_certificate_files; i++) {
+ key = options.certificates[i];
+ if (!sshkey_is_cert(key) || key->cert == NULL ||
+ key->cert->type != SSH2_CERT_TYPE_USER) {
+ debug_f("ignoring certificate %s: not a user "
+ "certificate", options.identity_files[i]);
+ continue;
+ }
+ if (key && sshkey_is_sk(key) && options.sk_provider == NULL) {
+ debug_f("ignoring authenticator-hosted key "
+ "certificate %s as no "
+ "SecurityKeyProvider has been specified",
+ options.identity_files[i]);
+ continue;
+ }
+ id = xcalloc(1, sizeof(*id));
+ id->agent_fd = -1;
+ id->key = key;
+ id->filename = xstrdup(options.certificate_files[i]);
+ id->userprovided = options.certificate_file_userprovided[i];
+ TAILQ_INSERT_TAIL(preferred, id, next);
+ }
+ /* list of keys supported by the agent */
+ if ((r = get_agent_identities(ssh, &agent_fd, &idlist)) == 0) {
+ for (j = 0; j < idlist->nkeys; j++) {
+ if ((r = sshkey_check_rsa_length(idlist->keys[j],
+ options.required_rsa_size)) != 0) {
+ debug_fr(r, "ignoring %s agent key",
+ sshkey_ssh_name(idlist->keys[j]));
+ continue;
+ }
+ found = 0;
+ TAILQ_FOREACH(id, &files, next) {
+ /*
+ * 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->agent_fd = agent_fd;
+ found = 1;
+ break;
+ }
+ }
+ if (!found && !options.identities_only) {
+ id = xcalloc(1, sizeof(*id));
+ /* 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 */
+ TAILQ_CONCAT(preferred, &agent, next);
+ authctxt->agent_fd = agent_fd;
+ }
+ /* Prefer PKCS11 keys that are explicitly listed */
+ TAILQ_FOREACH_SAFE(id, &files, next, tmp) {
+ if (id->key == NULL || (id->key->flags & SSHKEY_FLAG_EXT) == 0)
+ continue;
+ found = 0;
+ TAILQ_FOREACH(id2, &files, next) {
+ if (id2->key == NULL ||
+ (id2->key->flags & SSHKEY_FLAG_EXT) != 0)
+ continue;
+ if (sshkey_equal(id->key, id2->key)) {
+ TAILQ_REMOVE(&files, id, next);
+ TAILQ_INSERT_TAIL(preferred, id, next);
+ found = 1;
+ break;
+ }
+ }
+ /* If IdentitiesOnly set and key not found then don't use it */
+ if (!found && options.identities_only) {
+ TAILQ_REMOVE(&files, id, next);
+ freezero(id, sizeof(*id));
+ }
+ }
+ /* append remaining keys from the config file */
+ TAILQ_CONCAT(preferred, &files, next);
+ /* finally, filter by PubkeyAcceptedAlgorithms */
+ TAILQ_FOREACH_SAFE(id, preferred, next, id2) {
+ if (id->key != NULL && !key_type_allowed_by_config(id->key)) {
+ debug("Skipping %s key %s - "
+ "corresponding algo not in PubkeyAcceptedAlgorithms",
+ sshkey_ssh_name(id->key), id->filename);
+ TAILQ_REMOVE(preferred, id, next);
+ sshkey_free(id->key);
+ free(id->filename);
+ memset(id, 0, sizeof(*id));
+ continue;
+ }
+ }
+ /* List the keys we plan on using */
+ TAILQ_FOREACH_SAFE(id, preferred, next, id2) {
+ ident = format_identity(id);
+ debug("Will attempt key: %s", ident);
+ free(ident);
+ }
+ debug2_f("done");
+}
+
+static void
+pubkey_cleanup(struct ssh *ssh)
+{
+ Authctxt *authctxt = (Authctxt *)ssh->authctxt;
+ Identity *id;
+
+ if (authctxt->agent_fd != -1) {
+ ssh_close_authentication_socket(authctxt->agent_fd);
+ authctxt->agent_fd = -1;
+ }
+ for (id = TAILQ_FIRST(&authctxt->keys); id;
+ id = TAILQ_FIRST(&authctxt->keys)) {
+ TAILQ_REMOVE(&authctxt->keys, id, next);
+ sshkey_free(id->key);
+ free(id->filename);
+ free(id);
+ }
+}
+
+static void
+pubkey_reset(Authctxt *authctxt)
+{
+ Identity *id;
+
+ TAILQ_FOREACH(id, &authctxt->keys, next)
+ id->tried = 0;
+}
+
+static int
+try_identity(struct ssh *ssh, Identity *id)
+{
+ if (!id->key)
+ return (0);
+ if (sshkey_type_plain(id->key->type) == KEY_RSA &&
+ (ssh->compat & SSH_BUG_RSASIGMD5) != 0) {
+ debug("Skipped %s key %s for RSA/MD5 server",
+ sshkey_type(id->key), id->filename);
+ return (0);
+ }
+ return 1;
+}
+
+static int
+userauth_pubkey(struct ssh *ssh)
+{
+ Authctxt *authctxt = (Authctxt *)ssh->authctxt;
+ Identity *id;
+ int sent = 0;
+ char *ident;
+
+ while ((id = TAILQ_FIRST(&authctxt->keys))) {
+ if (id->tried++)
+ return (0);
+ /* move key to the end of the queue */
+ 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 != NULL) {
+ if (try_identity(ssh, id)) {
+ ident = format_identity(id);
+ debug("Offering public key: %s", ident);
+ free(ident);
+ sent = send_pubkey_test(ssh, id);
+ }
+ } else {
+ debug("Trying private key: %s", id->filename);
+ id->key = load_identity_file(id);
+ if (id->key != NULL) {
+ if (try_identity(ssh, id)) {
+ id->isprivate = 1;
+ sent = sign_and_send_pubkey(ssh, id);
+ }
+ sshkey_free(id->key);
+ id->key = NULL;
+ id->isprivate = 0;
+ }
+ }
+ if (sent)
+ return (sent);
+ }
+ return (0);
+}
+
+/*
+ * Send userauth request message specifying keyboard-interactive method.
+ */
+static int
+userauth_kbdint(struct ssh *ssh)
+{
+ Authctxt *authctxt = (Authctxt *)ssh->authctxt;
+ int r;
+
+ if (authctxt->attempt_kbdint++ >= options.number_of_password_prompts)
+ return 0;
+ /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
+ if (authctxt->attempt_kbdint > 1 && !authctxt->info_req_seen) {
+ debug3("userauth_kbdint: disable: no info_req_seen");
+ ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
+ return 0;
+ }
+
+ debug2("userauth_kbdint");
+ 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, "")) != 0 || /* lang */
+ (r = sshpkt_put_cstring(ssh, options.kbd_interactive_devices ?
+ options.kbd_interactive_devices : "")) != 0 ||
+ (r = sshpkt_send(ssh)) != 0)
+ fatal_fr(r, "send packet");
+
+ ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
+ return 1;
+}
+
+/*
+ * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
+ */
+static int
+input_userauth_info_req(int type, u_int32_t seq, struct ssh *ssh)
+{
+ Authctxt *authctxt = ssh->authctxt;
+ char *name = NULL, *inst = NULL, *lang = NULL, *prompt = NULL;
+ char *display_prompt = NULL, *response = NULL;
+ u_char echo = 0;
+ u_int num_prompts, i;
+ int r;
+
+ debug2_f("entering");
+
+ if (authctxt == NULL)
+ fatal_f("no authentication context");
+
+ authctxt->info_req_seen = 1;
+
+ if ((r = sshpkt_get_cstring(ssh, &name, NULL)) != 0 ||
+ (r = sshpkt_get_cstring(ssh, &inst, NULL)) != 0 ||
+ (r = sshpkt_get_cstring(ssh, &lang, NULL)) != 0)
+ goto out;
+ if (strlen(name) > 0)
+ logit("%s", name);
+ if (strlen(inst) > 0)
+ logit("%s", inst);
+
+ if ((r = sshpkt_get_u32(ssh, &num_prompts)) != 0)
+ goto out;
+ /*
+ * Begin to build info response packet based on prompts requested.
+ * We commit to providing the correct number of responses, so if
+ * further on we run into a problem that prevents this, we have to
+ * be sure and clean this up and send a correct error response.
+ */
+ if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE)) != 0 ||
+ (r = sshpkt_put_u32(ssh, num_prompts)) != 0)
+ goto out;
+
+ debug2_f("num_prompts %d", num_prompts);
+ for (i = 0; i < num_prompts; i++) {
+ if ((r = sshpkt_get_cstring(ssh, &prompt, NULL)) != 0 ||
+ (r = sshpkt_get_u8(ssh, &echo)) != 0)
+ goto out;
+ if (asmprintf(&display_prompt, INT_MAX, NULL, "(%s@%s) %s",
+ authctxt->server_user, options.host_key_alias ?
+ options.host_key_alias : authctxt->host, prompt) == -1)
+ fatal_f("asmprintf failed");
+ response = read_passphrase(display_prompt, echo ? RP_ECHO : 0);
+ if ((r = sshpkt_put_cstring(ssh, response)) != 0)
+ goto out;
+ freezero(response, strlen(response));
+ free(prompt);
+ free(display_prompt);
+ display_prompt = response = prompt = NULL;
+ }
+ /* done with parsing incoming message. */
+ if ((r = sshpkt_get_end(ssh)) != 0 ||
+ (r = sshpkt_add_padding(ssh, 64)) != 0)
+ goto out;
+ r = sshpkt_send(ssh);
+ out:
+ if (response)
+ freezero(response, strlen(response));
+ free(prompt);
+ free(display_prompt);
+ free(name);
+ free(inst);
+ free(lang);
+ return r;
+}
+
+static int
+ssh_keysign(struct ssh *ssh, struct sshkey *key, u_char **sigp, size_t *lenp,
+ const u_char *data, size_t datalen)
+{
+ struct sshbuf *b;
+ struct stat st;
+ pid_t pid;
+ int r, to[2], from[2], status;
+ int sock = ssh_packet_get_connection_in(ssh);
+ u_char rversion = 0, version = 2;
+ void (*osigchld)(int);
+
+ *sigp = NULL;
+ *lenp = 0;
+
+ if (stat(_PATH_SSH_KEY_SIGN, &st) == -1) {
+ error_f("not installed: %s", strerror(errno));
+ return -1;
+ }
+ if (fflush(stdout) != 0) {
+ error_f("fflush: %s", strerror(errno));
+ return -1;
+ }
+ if (pipe(to) == -1) {
+ error_f("pipe: %s", strerror(errno));
+ return -1;
+ }
+ if (pipe(from) == -1) {
+ error_f("pipe: %s", strerror(errno));
+ return -1;
+ }
+ if ((pid = fork()) == -1) {
+ error_f("fork: %s", strerror(errno));
+ return -1;
+ }
+ osigchld = ssh_signal(SIGCHLD, SIG_DFL);
+ if (pid == 0) {
+ close(from[0]);
+ if (dup2(from[1], STDOUT_FILENO) == -1)
+ fatal_f("dup2: %s", strerror(errno));
+ close(to[1]);
+ if (dup2(to[0], STDIN_FILENO) == -1)
+ fatal_f("dup2: %s", strerror(errno));
+ close(from[1]);
+ close(to[0]);
+
+ if (dup2(sock, STDERR_FILENO + 1) == -1)
+ fatal_f("dup2: %s", strerror(errno));
+ sock = STDERR_FILENO + 1;
+ fcntl(sock, F_SETFD, 0); /* keep the socket on exec */
+ closefrom(sock + 1);
+
+ debug3_f("[child] pid=%ld, exec %s",
+ (long)getpid(), _PATH_SSH_KEY_SIGN);
+ execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *)NULL);
+ fatal_f("exec(%s): %s", _PATH_SSH_KEY_SIGN,
+ strerror(errno));
+ }
+ close(from[1]);
+ close(to[0]);
+ sock = STDERR_FILENO + 1;
+
+ if ((b = sshbuf_new()) == NULL)
+ fatal_f("sshbuf_new failed");
+ /* send # of sock, data to be signed */
+ if ((r = sshbuf_put_u32(b, sock)) != 0 ||
+ (r = sshbuf_put_string(b, data, datalen)) != 0)
+ fatal_fr(r, "buffer error");
+ if (ssh_msg_send(to[1], version, b) == -1)
+ fatal_f("couldn't send request");
+ sshbuf_reset(b);
+ r = ssh_msg_recv(from[0], b);
+ close(from[0]);
+ close(to[1]);
+ if (r < 0) {
+ error_f("no reply");
+ goto fail;
+ }
+
+ errno = 0;
+ while (waitpid(pid, &status, 0) == -1) {
+ if (errno != EINTR) {
+ error_f("waitpid %ld: %s", (long)pid, strerror(errno));
+ goto fail;
+ }
+ }
+ if (!WIFEXITED(status)) {
+ error_f("exited abnormally");
+ goto fail;
+ }
+ if (WEXITSTATUS(status) != 0) {
+ error_f("exited with status %d", WEXITSTATUS(status));
+ goto fail;
+ }
+ if ((r = sshbuf_get_u8(b, &rversion)) != 0) {
+ error_fr(r, "buffer error");
+ goto fail;
+ }
+ if (rversion != version) {
+ error_f("bad version");
+ goto fail;
+ }
+ if ((r = sshbuf_get_string(b, sigp, lenp)) != 0) {
+ error_fr(r, "buffer error");
+ fail:
+ ssh_signal(SIGCHLD, osigchld);
+ sshbuf_free(b);
+ return -1;
+ }
+ ssh_signal(SIGCHLD, osigchld);
+ sshbuf_free(b);
+
+ return 0;
+}
+
+static int
+userauth_hostbased(struct ssh *ssh)
+{
+ Authctxt *authctxt = (Authctxt *)ssh->authctxt;
+ struct sshkey *private = NULL;
+ struct sshbuf *b = NULL;
+ 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_accepted_algos);
+ authctxt->ktypes = authctxt->oktypes;
+ }
+
+ /*
+ * Work through each listed type pattern in HostbasedAcceptedAlgorithms,
+ * 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_f("trying key type %s", 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_UNSPEC)
+ continue;
+ if (!sshkey_match_keyname_to_sigalgs(
+ sshkey_ssh_name(authctxt->sensitive->keys[i]),
+ authctxt->active_ktype))
+ continue;
+ /* we take and free the key */
+ 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 (private == NULL) {
+ free(authctxt->oktypes);
+ authctxt->oktypes = authctxt->ktypes = NULL;
+ authctxt->active_ktype = NULL;
+ debug("No more client hostkeys for hostbased authentication.");
+ goto out;
+ }
+
+ if ((fp = sshkey_fingerprint(private, options.fingerprint_hash,
+ SSH_FP_DEFAULT)) == NULL) {
+ error_f("sshkey_fingerprint failed");
+ goto out;
+ }
+ debug_f("trying hostkey %s %s using sigalg %s",
+ sshkey_ssh_name(private), fp, authctxt->active_ktype);
+
+ /* figure out a name for the client host */
+ lname = get_local_name(ssh_packet_get_connection_in(ssh));
+ if (lname == NULL) {
+ error_f("cannot get local ipaddr/name");
+ goto out;
+ }
+
+ /* XXX sshbuf_put_stringf? */
+ xasprintf(&chost, "%s.", lname);
+ debug2_f("chost %s", chost);
+
+ /* construct data */
+ if ((b = sshbuf_new()) == NULL) {
+ error_f("sshbuf_new failed");
+ goto out;
+ }
+ if ((r = sshkey_to_blob(private, &keyblob, &keylen)) != 0) {
+ error_fr(r, "sshkey_to_blob");
+ goto out;
+ }
+ if ((r = sshbuf_put_stringb(b, ssh->kex->session_id)) != 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, authctxt->service)) != 0 ||
+ (r = sshbuf_put_cstring(b, authctxt->method->name)) != 0 ||
+ (r = sshbuf_put_cstring(b, authctxt->active_ktype)) != 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_fr(r, "buffer error");
+ goto out;
+ }
+
+#ifdef DEBUG_PK
+ sshbuf_dump(b, stderr);
+#endif
+ if ((r = ssh_keysign(ssh, private, &sig, &siglen,
+ sshbuf_ptr(b), sshbuf_len(b))) != 0) {
+ error("sign using hostkey %s %s failed",
+ sshkey_ssh_name(private), fp);
+ goto out;
+ }
+ 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, authctxt->active_ktype)) != 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_fr(r, "packet error");
+ goto out;
+ }
+ success = 1;
+
+ out:
+ if (sig != NULL)
+ freezero(sig, siglen);
+ free(keyblob);
+ free(lname);
+ free(fp);
+ free(chost);
+ sshkey_free(private);
+ sshbuf_free(b);
+
+ return success;
+}
+
+/* find auth method */
+
+/*
+ * given auth method name, if configurable options permit this method fill
+ * in auth_ident field and return true, otherwise return false.
+ */
+static int
+authmethod_is_enabled(Authmethod *method)
+{
+ if (method == NULL)
+ return 0;
+ /* return false if options indicate this method is disabled */
+ if (method->enabled == NULL || *method->enabled == 0)
+ return 0;
+ /* return false if batch mode is enabled but method needs interactive mode */
+ if (method->batch_flag != NULL && *method->batch_flag != 0)
+ return 0;
+ return 1;
+}
+
+static Authmethod *
+authmethod_lookup(const char *name)
+{
+ Authmethod *method = NULL;
+ if (name != NULL)
+ for (method = authmethods; method->name != NULL; method++)
+ if (strcmp(name, method->name) == 0)
+ return method;
+ debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
+ return NULL;
+}
+
+/* XXX internal state */
+static Authmethod *current = NULL;
+static char *supported = NULL;
+static char *preferred = NULL;
+
+/*
+ * Given the authentication method list sent by the server, return the
+ * next method we should try. If the server initially sends a nil list,
+ * use a built-in default list.
+ */
+static Authmethod *
+authmethod_get(char *authlist)
+{
+ char *name = NULL;
+ u_int next;
+
+ /* Use a suitable default if we're passed a nil list. */
+ if (authlist == NULL || strlen(authlist) == 0)
+ authlist = options.preferred_authentications;
+
+ if (supported == NULL || strcmp(authlist, supported) != 0) {
+ debug3("start over, passed a different list %s", authlist);
+ free(supported);
+ supported = xstrdup(authlist);
+ preferred = options.preferred_authentications;
+ debug3("preferred %s", preferred);
+ current = NULL;
+ } else if (current != NULL && authmethod_is_enabled(current))
+ return current;
+
+ for (;;) {
+ if ((name = match_list(preferred, supported, &next)) == NULL) {
+ debug("No more authentication methods to try.");
+ current = NULL;
+ return NULL;
+ }
+ preferred += next;
+ debug3("authmethod_lookup %s", name);
+ debug3("remaining preferred: %s", preferred);
+ if ((current = authmethod_lookup(name)) != NULL &&
+ authmethod_is_enabled(current)) {
+ debug3("authmethod_is_enabled %s", name);
+ debug("Next authentication method: %s", name);
+ free(name);
+ return current;
+ }
+ free(name);
+ }
+}
+
+static char *
+authmethods_get(void)
+{
+ Authmethod *method = NULL;
+ struct sshbuf *b;
+ char *list;
+ int r;
+
+ if ((b = sshbuf_new()) == NULL)
+ fatal_f("sshbuf_new failed");
+ for (method = authmethods; method->name != NULL; method++) {
+ if (authmethod_is_enabled(method)) {
+ if ((r = sshbuf_putf(b, "%s%s",
+ sshbuf_len(b) ? "," : "", method->name)) != 0)
+ fatal_fr(r, "buffer error");
+ }
+ }
+ if ((list = sshbuf_dup_string(b)) == NULL)
+ fatal_f("sshbuf_dup_string failed");
+ sshbuf_free(b);
+ return list;
+}