1466 lines
38 KiB
C
1466 lines
38 KiB
C
/*
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* Copyright (c) 2000 Markus Friedl. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "includes.h"
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RCSID("$OpenBSD: sshconnect2.c,v 1.124 2003/08/25 10:33:33 djm Exp $");
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#include "openbsd-compat/sys-queue.h"
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#include "ssh.h"
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#include "ssh2.h"
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#include "xmalloc.h"
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#include "buffer.h"
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#include "packet.h"
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#include "compat.h"
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#include "bufaux.h"
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#include "cipher.h"
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#include "kex.h"
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#include "myproposal.h"
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#include "sshconnect.h"
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#include "authfile.h"
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#include "dh.h"
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#include "authfd.h"
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#include "log.h"
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#include "readconf.h"
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#include "readpass.h"
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#include "match.h"
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#include "dispatch.h"
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#include "canohost.h"
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#include "msg.h"
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#include "pathnames.h"
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#ifdef GSSAPI
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#include "ssh-gss.h"
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#endif
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/* import */
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extern char *client_version_string;
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extern char *server_version_string;
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extern Options options;
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/*
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* SSH2 key exchange
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*/
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u_char *session_id2 = NULL;
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u_int session_id2_len = 0;
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char *xxx_host;
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struct sockaddr *xxx_hostaddr;
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Kex *xxx_kex = NULL;
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static int
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verify_host_key_callback(Key *hostkey)
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{
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if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1)
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fatal("Host key verification failed.");
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return 0;
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}
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void
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ssh_kex2(char *host, struct sockaddr *hostaddr)
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{
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Kex *kex;
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xxx_host = host;
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xxx_hostaddr = hostaddr;
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if (options.ciphers == (char *)-1) {
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logit("No valid ciphers for protocol version 2 given, using defaults.");
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options.ciphers = NULL;
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}
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if (options.ciphers != NULL) {
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myproposal[PROPOSAL_ENC_ALGS_CTOS] =
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myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
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}
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myproposal[PROPOSAL_ENC_ALGS_CTOS] =
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compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]);
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myproposal[PROPOSAL_ENC_ALGS_STOC] =
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compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]);
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if (options.compression) {
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myproposal[PROPOSAL_COMP_ALGS_CTOS] =
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myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib,none";
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} else {
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myproposal[PROPOSAL_COMP_ALGS_CTOS] =
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myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib";
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}
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if (options.macs != NULL) {
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myproposal[PROPOSAL_MAC_ALGS_CTOS] =
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myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
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}
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if (options.hostkeyalgorithms != NULL)
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myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
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options.hostkeyalgorithms;
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if (options.rekey_limit)
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packet_set_rekey_limit(options.rekey_limit);
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/* start key exchange */
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kex = kex_setup(myproposal);
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kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
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kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
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kex->client_version_string=client_version_string;
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kex->server_version_string=server_version_string;
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kex->verify_host_key=&verify_host_key_callback;
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xxx_kex = kex;
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dispatch_run(DISPATCH_BLOCK, &kex->done, kex);
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session_id2 = kex->session_id;
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session_id2_len = kex->session_id_len;
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#ifdef DEBUG_KEXDH
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/* send 1st encrypted/maced/compressed message */
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packet_start(SSH2_MSG_IGNORE);
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packet_put_cstring("markus");
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packet_send();
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packet_write_wait();
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#endif
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}
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/*
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* Authenticate user
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*/
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typedef struct Authctxt Authctxt;
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typedef struct Authmethod Authmethod;
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typedef struct identity Identity;
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typedef struct idlist Idlist;
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struct identity {
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TAILQ_ENTRY(identity) next;
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AuthenticationConnection *ac; /* set if agent supports key */
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Key *key; /* public/private key */
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char *filename; /* comment for agent-only keys */
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int tried;
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int isprivate; /* key points to the private key */
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};
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TAILQ_HEAD(idlist, identity);
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struct Authctxt {
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const char *server_user;
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const char *local_user;
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const char *host;
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const char *service;
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Authmethod *method;
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int success;
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char *authlist;
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/* pubkey */
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Idlist keys;
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AuthenticationConnection *agent;
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/* hostbased */
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Sensitive *sensitive;
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/* kbd-interactive */
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int info_req_seen;
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/* generic */
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void *methoddata;
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};
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struct Authmethod {
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char *name; /* string to compare against server's list */
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int (*userauth)(Authctxt *authctxt);
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int *enabled; /* flag in option struct that enables method */
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int *batch_flag; /* flag in option struct that disables method */
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};
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void input_userauth_success(int, u_int32_t, void *);
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void input_userauth_failure(int, u_int32_t, void *);
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void input_userauth_banner(int, u_int32_t, void *);
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void input_userauth_error(int, u_int32_t, void *);
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void input_userauth_info_req(int, u_int32_t, void *);
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void input_userauth_pk_ok(int, u_int32_t, void *);
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void input_userauth_passwd_changereq(int, u_int32_t, void *);
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int userauth_none(Authctxt *);
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int userauth_pubkey(Authctxt *);
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int userauth_passwd(Authctxt *);
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int userauth_kbdint(Authctxt *);
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int userauth_hostbased(Authctxt *);
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int userauth_kerberos(Authctxt *);
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#ifdef GSSAPI
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int userauth_gssapi(Authctxt *authctxt);
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void input_gssapi_response(int type, u_int32_t, void *);
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void input_gssapi_token(int type, u_int32_t, void *);
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void input_gssapi_hash(int type, u_int32_t, void *);
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void input_gssapi_error(int, u_int32_t, void *);
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void input_gssapi_errtok(int, u_int32_t, void *);
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#endif
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void userauth(Authctxt *, char *);
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static int sign_and_send_pubkey(Authctxt *, Identity *);
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static void pubkey_prepare(Authctxt *);
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static void pubkey_cleanup(Authctxt *);
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static Key *load_identity_file(char *);
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static Authmethod *authmethod_get(char *authlist);
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static Authmethod *authmethod_lookup(const char *name);
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static char *authmethods_get(void);
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Authmethod authmethods[] = {
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#ifdef GSSAPI
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{"gssapi",
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userauth_gssapi,
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&options.gss_authentication,
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NULL},
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#endif
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{"hostbased",
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userauth_hostbased,
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&options.hostbased_authentication,
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NULL},
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{"publickey",
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userauth_pubkey,
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&options.pubkey_authentication,
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NULL},
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{"keyboard-interactive",
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userauth_kbdint,
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&options.kbd_interactive_authentication,
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&options.batch_mode},
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{"password",
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userauth_passwd,
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&options.password_authentication,
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&options.batch_mode},
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{"none",
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userauth_none,
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NULL,
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NULL},
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{NULL, NULL, NULL, NULL}
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};
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void
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ssh_userauth2(const char *local_user, const char *server_user, char *host,
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Sensitive *sensitive)
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{
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Authctxt authctxt;
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int type;
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if (options.challenge_response_authentication)
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options.kbd_interactive_authentication = 1;
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packet_start(SSH2_MSG_SERVICE_REQUEST);
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packet_put_cstring("ssh-userauth");
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packet_send();
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debug("SSH2_MSG_SERVICE_REQUEST sent");
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packet_write_wait();
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type = packet_read();
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if (type != SSH2_MSG_SERVICE_ACCEPT)
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fatal("Server denied authentication request: %d", type);
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if (packet_remaining() > 0) {
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char *reply = packet_get_string(NULL);
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debug2("service_accept: %s", reply);
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xfree(reply);
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} else {
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debug2("buggy server: service_accept w/o service");
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}
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packet_check_eom();
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debug("SSH2_MSG_SERVICE_ACCEPT received");
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if (options.preferred_authentications == NULL)
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options.preferred_authentications = authmethods_get();
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/* setup authentication context */
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memset(&authctxt, 0, sizeof(authctxt));
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pubkey_prepare(&authctxt);
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authctxt.server_user = server_user;
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authctxt.local_user = local_user;
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authctxt.host = host;
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authctxt.service = "ssh-connection"; /* service name */
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authctxt.success = 0;
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authctxt.method = authmethod_lookup("none");
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authctxt.authlist = NULL;
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authctxt.methoddata = NULL;
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authctxt.sensitive = sensitive;
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authctxt.info_req_seen = 0;
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if (authctxt.method == NULL)
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fatal("ssh_userauth2: internal error: cannot send userauth none request");
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/* initial userauth request */
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userauth_none(&authctxt);
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dispatch_init(&input_userauth_error);
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dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
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dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
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dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
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dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */
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pubkey_cleanup(&authctxt);
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dispatch_range(SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
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debug("Authentication succeeded (%s).", authctxt.method->name);
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}
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void
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userauth(Authctxt *authctxt, char *authlist)
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{
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if (authctxt->methoddata) {
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xfree(authctxt->methoddata);
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authctxt->methoddata = NULL;
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}
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if (authlist == NULL) {
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authlist = authctxt->authlist;
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} else {
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if (authctxt->authlist)
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xfree(authctxt->authlist);
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authctxt->authlist = authlist;
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}
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for (;;) {
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Authmethod *method = authmethod_get(authlist);
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if (method == NULL)
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fatal("Permission denied (%s).", authlist);
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authctxt->method = method;
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/* reset the per method handler */
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dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN,
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SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
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/* and try new method */
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if (method->userauth(authctxt) != 0) {
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debug2("we sent a %s packet, wait for reply", method->name);
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break;
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} else {
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debug2("we did not send a packet, disable method");
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method->enabled = NULL;
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}
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}
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}
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void
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input_userauth_error(int type, u_int32_t seq, void *ctxt)
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{
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fatal("input_userauth_error: bad message during authentication: "
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"type %d", type);
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}
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void
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input_userauth_banner(int type, u_int32_t seq, void *ctxt)
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{
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char *msg, *lang;
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debug3("input_userauth_banner");
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msg = packet_get_string(NULL);
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lang = packet_get_string(NULL);
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logit("%s", msg);
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xfree(msg);
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xfree(lang);
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}
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void
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input_userauth_success(int type, u_int32_t seq, void *ctxt)
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{
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Authctxt *authctxt = ctxt;
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if (authctxt == NULL)
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fatal("input_userauth_success: no authentication context");
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if (authctxt->authlist)
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xfree(authctxt->authlist);
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if (authctxt->methoddata)
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xfree(authctxt->methoddata);
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authctxt->success = 1; /* break out */
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}
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void
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input_userauth_failure(int type, u_int32_t seq, void *ctxt)
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{
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Authctxt *authctxt = ctxt;
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char *authlist = NULL;
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int partial;
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if (authctxt == NULL)
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fatal("input_userauth_failure: no authentication context");
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authlist = packet_get_string(NULL);
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partial = packet_get_char();
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packet_check_eom();
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if (partial != 0)
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logit("Authenticated with partial success.");
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debug("Authentications that can continue: %s", authlist);
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userauth(authctxt, authlist);
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}
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void
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input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt)
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{
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Authctxt *authctxt = ctxt;
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Key *key = NULL;
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Identity *id = NULL;
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Buffer b;
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int pktype, sent = 0;
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u_int alen, blen;
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char *pkalg, *fp;
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u_char *pkblob;
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if (authctxt == NULL)
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fatal("input_userauth_pk_ok: no authentication context");
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if (datafellows & SSH_BUG_PKOK) {
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/* this is similar to SSH_BUG_PKAUTH */
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debug2("input_userauth_pk_ok: SSH_BUG_PKOK");
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pkblob = packet_get_string(&blen);
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buffer_init(&b);
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buffer_append(&b, pkblob, blen);
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pkalg = buffer_get_string(&b, &alen);
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buffer_free(&b);
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} else {
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pkalg = packet_get_string(&alen);
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pkblob = packet_get_string(&blen);
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}
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packet_check_eom();
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debug("Server accepts key: pkalg %s blen %u", pkalg, blen);
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if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) {
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debug("unknown pkalg %s", pkalg);
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goto done;
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}
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if ((key = key_from_blob(pkblob, blen)) == NULL) {
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debug("no key from blob. pkalg %s", pkalg);
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goto done;
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}
|
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if (key->type != pktype) {
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error("input_userauth_pk_ok: type mismatch "
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"for decoded key (received %d, expected %d)",
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key->type, pktype);
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goto done;
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}
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fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX);
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debug2("input_userauth_pk_ok: fp %s", fp);
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xfree(fp);
|
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|
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TAILQ_FOREACH(id, &authctxt->keys, next) {
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if (key_equal(key, id->key)) {
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sent = sign_and_send_pubkey(authctxt, id);
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break;
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}
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}
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done:
|
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if (key != NULL)
|
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key_free(key);
|
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xfree(pkalg);
|
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xfree(pkblob);
|
|
|
|
/* try another method if we did not send a packet */
|
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if (sent == 0)
|
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userauth(authctxt, NULL);
|
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}
|
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|
|
#ifdef GSSAPI
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int
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userauth_gssapi(Authctxt *authctxt)
|
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{
|
|
Gssctxt *gssctxt = NULL;
|
|
static gss_OID_set supported = NULL;
|
|
static int mech = 0;
|
|
OM_uint32 min;
|
|
int ok = 0;
|
|
|
|
/* Try one GSSAPI method at a time, rather than sending them all at
|
|
* once. */
|
|
|
|
if (supported == NULL)
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gss_indicate_mechs(&min, &supported);
|
|
|
|
/* Check to see if the mechanism is usable before we offer it */
|
|
while (mech<supported->count && !ok) {
|
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if (gssctxt)
|
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ssh_gssapi_delete_ctx(&gssctxt);
|
|
ssh_gssapi_build_ctx(&gssctxt);
|
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ssh_gssapi_set_oid(gssctxt, &supported->elements[mech]);
|
|
|
|
/* My DER encoding requires length<128 */
|
|
if (supported->elements[mech].length < 128 &&
|
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!GSS_ERROR(ssh_gssapi_import_name(gssctxt,
|
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authctxt->host))) {
|
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ok = 1; /* Mechanism works */
|
|
} else {
|
|
mech++;
|
|
}
|
|
}
|
|
|
|
if (!ok) return 0;
|
|
|
|
authctxt->methoddata=(void *)gssctxt;
|
|
|
|
packet_start(SSH2_MSG_USERAUTH_REQUEST);
|
|
packet_put_cstring(authctxt->server_user);
|
|
packet_put_cstring(authctxt->service);
|
|
packet_put_cstring(authctxt->method->name);
|
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|
|
packet_put_int(1);
|
|
|
|
/* Some servers encode the OID incorrectly (as we used to) */
|
|
if (datafellows & SSH_BUG_GSSAPI_BER) {
|
|
packet_put_string(supported->elements[mech].elements,
|
|
supported->elements[mech].length);
|
|
} else {
|
|
packet_put_int((supported->elements[mech].length)+2);
|
|
packet_put_char(SSH_GSS_OIDTYPE);
|
|
packet_put_char(supported->elements[mech].length);
|
|
packet_put_raw(supported->elements[mech].elements,
|
|
supported->elements[mech].length);
|
|
}
|
|
|
|
packet_send();
|
|
|
|
dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
|
|
dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
|
|
dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
|
|
dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
|
|
|
|
mech++; /* Move along to next candidate */
|
|
|
|
return 1;
|
|
}
|
|
|
|
void
|
|
input_gssapi_response(int type, u_int32_t plen, void *ctxt)
|
|
{
|
|
Authctxt *authctxt = ctxt;
|
|
Gssctxt *gssctxt;
|
|
OM_uint32 status, ms;
|
|
int oidlen;
|
|
char *oidv;
|
|
gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
|
|
|
|
if (authctxt == NULL)
|
|
fatal("input_gssapi_response: no authentication context");
|
|
gssctxt = authctxt->methoddata;
|
|
|
|
/* Setup our OID */
|
|
oidv = packet_get_string(&oidlen);
|
|
|
|
if (datafellows & SSH_BUG_GSSAPI_BER) {
|
|
if (!ssh_gssapi_check_oid(gssctxt, oidv, oidlen))
|
|
fatal("Server returned different OID than expected");
|
|
} else {
|
|
if(oidv[0] != SSH_GSS_OIDTYPE || oidv[1] != oidlen-2) {
|
|
debug("Badly encoded mechanism OID received");
|
|
userauth(authctxt, NULL);
|
|
xfree(oidv);
|
|
return;
|
|
}
|
|
if (!ssh_gssapi_check_oid(gssctxt, oidv+2, oidlen-2))
|
|
fatal("Server returned different OID than expected");
|
|
}
|
|
|
|
packet_check_eom();
|
|
|
|
xfree(oidv);
|
|
|
|
status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
|
|
GSS_C_NO_BUFFER, &send_tok, NULL);
|
|
if (GSS_ERROR(status)) {
|
|
if (send_tok.length > 0) {
|
|
packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
|
|
packet_put_string(send_tok.value, send_tok.length);
|
|
packet_send();
|
|
gss_release_buffer(&ms, &send_tok);
|
|
}
|
|
/* Start again with next method on list */
|
|
debug("Trying to start again");
|
|
userauth(authctxt, NULL);
|
|
return;
|
|
}
|
|
|
|
/* We must have data to send */
|
|
packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
|
|
packet_put_string(send_tok.value, send_tok.length);
|
|
packet_send();
|
|
gss_release_buffer(&ms, &send_tok);
|
|
}
|
|
|
|
void
|
|
input_gssapi_token(int type, u_int32_t plen, void *ctxt)
|
|
{
|
|
Authctxt *authctxt = ctxt;
|
|
Gssctxt *gssctxt;
|
|
gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
|
|
gss_buffer_desc recv_tok;
|
|
OM_uint32 status, ms;
|
|
u_int slen;
|
|
|
|
if (authctxt == NULL)
|
|
fatal("input_gssapi_response: no authentication context");
|
|
gssctxt = authctxt->methoddata;
|
|
|
|
recv_tok.value = packet_get_string(&slen);
|
|
recv_tok.length = slen; /* safe typecast */
|
|
|
|
packet_check_eom();
|
|
|
|
status=ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
|
|
&recv_tok, &send_tok, NULL);
|
|
|
|
xfree(recv_tok.value);
|
|
|
|
if (GSS_ERROR(status)) {
|
|
if (send_tok.length > 0) {
|
|
packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
|
|
packet_put_string(send_tok.value, send_tok.length);
|
|
packet_send();
|
|
gss_release_buffer(&ms, &send_tok);
|
|
}
|
|
/* Start again with the next method in the list */
|
|
userauth(authctxt, NULL);
|
|
return;
|
|
}
|
|
|
|
if (send_tok.length > 0) {
|
|
packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
|
|
packet_put_string(send_tok.value, send_tok.length);
|
|
packet_send();
|
|
gss_release_buffer(&ms, &send_tok);
|
|
}
|
|
|
|
if (status == GSS_S_COMPLETE) {
|
|
/* If that succeeded, send a exchange complete message */
|
|
packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE);
|
|
packet_send();
|
|
}
|
|
}
|
|
|
|
void
|
|
input_gssapi_errtok(int type, u_int32_t plen, void *ctxt)
|
|
{
|
|
Authctxt *authctxt = ctxt;
|
|
Gssctxt *gssctxt;
|
|
gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
|
|
gss_buffer_desc recv_tok;
|
|
OM_uint32 status, ms;
|
|
u_int len;
|
|
|
|
if (authctxt == NULL)
|
|
fatal("input_gssapi_response: no authentication context");
|
|
gssctxt = authctxt->methoddata;
|
|
|
|
recv_tok.value = packet_get_string(&len);
|
|
recv_tok.length = len;
|
|
|
|
packet_check_eom();
|
|
|
|
/* Stick it into GSSAPI and see what it says */
|
|
status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
|
|
&recv_tok, &send_tok, NULL);
|
|
|
|
xfree(recv_tok.value);
|
|
gss_release_buffer(&ms, &send_tok);
|
|
|
|
/* Server will be returning a failed packet after this one */
|
|
}
|
|
|
|
void
|
|
input_gssapi_error(int type, u_int32_t plen, void *ctxt)
|
|
{
|
|
OM_uint32 maj, min;
|
|
char *msg;
|
|
char *lang;
|
|
|
|
maj=packet_get_int();
|
|
min=packet_get_int();
|
|
msg=packet_get_string(NULL);
|
|
lang=packet_get_string(NULL);
|
|
|
|
packet_check_eom();
|
|
|
|
debug("Server GSSAPI Error:\n%s\n", msg);
|
|
xfree(msg);
|
|
xfree(lang);
|
|
}
|
|
#endif /* GSSAPI */
|
|
|
|
int
|
|
userauth_none(Authctxt *authctxt)
|
|
{
|
|
/* initial userauth request */
|
|
packet_start(SSH2_MSG_USERAUTH_REQUEST);
|
|
packet_put_cstring(authctxt->server_user);
|
|
packet_put_cstring(authctxt->service);
|
|
packet_put_cstring(authctxt->method->name);
|
|
packet_send();
|
|
return 1;
|
|
}
|
|
|
|
int
|
|
userauth_passwd(Authctxt *authctxt)
|
|
{
|
|
static int attempt = 0;
|
|
char prompt[150];
|
|
char *password;
|
|
|
|
if (attempt++ >= options.number_of_password_prompts)
|
|
return 0;
|
|
|
|
if (attempt != 1)
|
|
error("Permission denied, please try again.");
|
|
|
|
snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
|
|
authctxt->server_user, authctxt->host);
|
|
password = read_passphrase(prompt, 0);
|
|
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_char(0);
|
|
packet_put_cstring(password);
|
|
memset(password, 0, strlen(password));
|
|
xfree(password);
|
|
packet_add_padding(64);
|
|
packet_send();
|
|
|
|
dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
|
|
&input_userauth_passwd_changereq);
|
|
|
|
return 1;
|
|
}
|
|
/*
|
|
* parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
|
|
*/
|
|
void
|
|
input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt)
|
|
{
|
|
Authctxt *authctxt = ctxt;
|
|
char *info, *lang, *password = NULL, *retype = NULL;
|
|
char prompt[150];
|
|
|
|
debug2("input_userauth_passwd_changereq");
|
|
|
|
if (authctxt == NULL)
|
|
fatal("input_userauth_passwd_changereq: "
|
|
"no authentication context");
|
|
|
|
info = packet_get_string(NULL);
|
|
lang = packet_get_string(NULL);
|
|
if (strlen(info) > 0)
|
|
logit("%s", info);
|
|
xfree(info);
|
|
xfree(lang);
|
|
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_char(1); /* additional info */
|
|
snprintf(prompt, sizeof(prompt),
|
|
"Enter %.30s@%.128s's old password: ",
|
|
authctxt->server_user, authctxt->host);
|
|
password = read_passphrase(prompt, 0);
|
|
packet_put_cstring(password);
|
|
memset(password, 0, strlen(password));
|
|
xfree(password);
|
|
password = NULL;
|
|
while (password == NULL) {
|
|
snprintf(prompt, sizeof(prompt),
|
|
"Enter %.30s@%.128s's new password: ",
|
|
authctxt->server_user, authctxt->host);
|
|
password = read_passphrase(prompt, RP_ALLOW_EOF);
|
|
if (password == NULL) {
|
|
/* bail out */
|
|
return;
|
|
}
|
|
snprintf(prompt, sizeof(prompt),
|
|
"Retype %.30s@%.128s's new password: ",
|
|
authctxt->server_user, authctxt->host);
|
|
retype = read_passphrase(prompt, 0);
|
|
if (strcmp(password, retype) != 0) {
|
|
memset(password, 0, strlen(password));
|
|
xfree(password);
|
|
logit("Mismatch; try again, EOF to quit.");
|
|
password = NULL;
|
|
}
|
|
memset(retype, 0, strlen(retype));
|
|
xfree(retype);
|
|
}
|
|
packet_put_cstring(password);
|
|
memset(password, 0, strlen(password));
|
|
xfree(password);
|
|
packet_add_padding(64);
|
|
packet_send();
|
|
|
|
dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
|
|
&input_userauth_passwd_changereq);
|
|
}
|
|
|
|
static int
|
|
identity_sign(Identity *id, u_char **sigp, u_int *lenp,
|
|
u_char *data, u_int datalen)
|
|
{
|
|
Key *prv;
|
|
int ret;
|
|
|
|
/* the agent supports this key */
|
|
if (id->ac)
|
|
return (ssh_agent_sign(id->ac, id->key, sigp, lenp,
|
|
data, datalen));
|
|
/*
|
|
* we have already loaded the private key or
|
|
* the private key is stored in external hardware
|
|
*/
|
|
if (id->isprivate || (id->key->flags & KEY_FLAG_EXT))
|
|
return (key_sign(id->key, sigp, lenp, data, datalen));
|
|
/* load the private key from the file */
|
|
if ((prv = load_identity_file(id->filename)) == NULL)
|
|
return (-1);
|
|
ret = key_sign(prv, sigp, lenp, data, datalen);
|
|
key_free(prv);
|
|
return (ret);
|
|
}
|
|
|
|
static int
|
|
sign_and_send_pubkey(Authctxt *authctxt, Identity *id)
|
|
{
|
|
Buffer b;
|
|
u_char *blob, *signature;
|
|
u_int bloblen, slen;
|
|
u_int skip = 0;
|
|
int ret = -1;
|
|
int have_sig = 1;
|
|
|
|
debug3("sign_and_send_pubkey");
|
|
|
|
if (key_to_blob(id->key, &blob, &bloblen) == 0) {
|
|
/* we cannot handle this key */
|
|
debug3("sign_and_send_pubkey: cannot handle key");
|
|
return 0;
|
|
}
|
|
/* data to be signed */
|
|
buffer_init(&b);
|
|
if (datafellows & SSH_OLD_SESSIONID) {
|
|
buffer_append(&b, session_id2, session_id2_len);
|
|
skip = session_id2_len;
|
|
} else {
|
|
buffer_put_string(&b, session_id2, session_id2_len);
|
|
skip = buffer_len(&b);
|
|
}
|
|
buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
|
|
buffer_put_cstring(&b, authctxt->server_user);
|
|
buffer_put_cstring(&b,
|
|
datafellows & SSH_BUG_PKSERVICE ?
|
|
"ssh-userauth" :
|
|
authctxt->service);
|
|
if (datafellows & SSH_BUG_PKAUTH) {
|
|
buffer_put_char(&b, have_sig);
|
|
} else {
|
|
buffer_put_cstring(&b, authctxt->method->name);
|
|
buffer_put_char(&b, have_sig);
|
|
buffer_put_cstring(&b, key_ssh_name(id->key));
|
|
}
|
|
buffer_put_string(&b, blob, bloblen);
|
|
|
|
/* generate signature */
|
|
ret = identity_sign(id, &signature, &slen,
|
|
buffer_ptr(&b), buffer_len(&b));
|
|
if (ret == -1) {
|
|
xfree(blob);
|
|
buffer_free(&b);
|
|
return 0;
|
|
}
|
|
#ifdef DEBUG_PK
|
|
buffer_dump(&b);
|
|
#endif
|
|
if (datafellows & SSH_BUG_PKSERVICE) {
|
|
buffer_clear(&b);
|
|
buffer_append(&b, session_id2, session_id2_len);
|
|
skip = session_id2_len;
|
|
buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
|
|
buffer_put_cstring(&b, authctxt->server_user);
|
|
buffer_put_cstring(&b, authctxt->service);
|
|
buffer_put_cstring(&b, authctxt->method->name);
|
|
buffer_put_char(&b, have_sig);
|
|
if (!(datafellows & SSH_BUG_PKAUTH))
|
|
buffer_put_cstring(&b, key_ssh_name(id->key));
|
|
buffer_put_string(&b, blob, bloblen);
|
|
}
|
|
xfree(blob);
|
|
|
|
/* append signature */
|
|
buffer_put_string(&b, signature, slen);
|
|
xfree(signature);
|
|
|
|
/* skip session id and packet type */
|
|
if (buffer_len(&b) < skip + 1)
|
|
fatal("userauth_pubkey: internal error");
|
|
buffer_consume(&b, skip + 1);
|
|
|
|
/* put remaining data from buffer into packet */
|
|
packet_start(SSH2_MSG_USERAUTH_REQUEST);
|
|
packet_put_raw(buffer_ptr(&b), buffer_len(&b));
|
|
buffer_free(&b);
|
|
packet_send();
|
|
|
|
return 1;
|
|
}
|
|
|
|
static int
|
|
send_pubkey_test(Authctxt *authctxt, Identity *id)
|
|
{
|
|
u_char *blob;
|
|
u_int bloblen, have_sig = 0;
|
|
|
|
debug3("send_pubkey_test");
|
|
|
|
if (key_to_blob(id->key, &blob, &bloblen) == 0) {
|
|
/* we cannot handle this key */
|
|
debug3("send_pubkey_test: cannot handle key");
|
|
return 0;
|
|
}
|
|
/* register callback for USERAUTH_PK_OK message */
|
|
dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
|
|
|
|
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_char(have_sig);
|
|
if (!(datafellows & SSH_BUG_PKAUTH))
|
|
packet_put_cstring(key_ssh_name(id->key));
|
|
packet_put_string(blob, bloblen);
|
|
xfree(blob);
|
|
packet_send();
|
|
return 1;
|
|
}
|
|
|
|
static Key *
|
|
load_identity_file(char *filename)
|
|
{
|
|
Key *private;
|
|
char prompt[300], *passphrase;
|
|
int quit, i;
|
|
struct stat st;
|
|
|
|
if (stat(filename, &st) < 0) {
|
|
debug3("no such identity: %s", filename);
|
|
return NULL;
|
|
}
|
|
private = key_load_private_type(KEY_UNSPEC, filename, "", 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++) {
|
|
passphrase = read_passphrase(prompt, 0);
|
|
if (strcmp(passphrase, "") != 0) {
|
|
private = key_load_private_type(KEY_UNSPEC, filename,
|
|
passphrase, NULL);
|
|
quit = 0;
|
|
} else {
|
|
debug2("no passphrase given, try next key");
|
|
quit = 1;
|
|
}
|
|
memset(passphrase, 0, strlen(passphrase));
|
|
xfree(passphrase);
|
|
if (private != NULL || quit)
|
|
break;
|
|
debug2("bad passphrase given, try again...");
|
|
}
|
|
}
|
|
return private;
|
|
}
|
|
|
|
/*
|
|
* try keys in the following order:
|
|
* 1. agent keys that are found in the config file
|
|
* 2. other agent keys
|
|
* 3. keys that are only listed in the config file
|
|
*/
|
|
static void
|
|
pubkey_prepare(Authctxt *authctxt)
|
|
{
|
|
Identity *id;
|
|
Idlist agent, files, *preferred;
|
|
Key *key;
|
|
AuthenticationConnection *ac;
|
|
char *comment;
|
|
int i, found;
|
|
|
|
TAILQ_INIT(&agent); /* keys from the agent */
|
|
TAILQ_INIT(&files); /* keys from the config file */
|
|
preferred = &authctxt->keys;
|
|
TAILQ_INIT(preferred); /* preferred order of keys */
|
|
|
|
/* list of keys stored in the filesystem */
|
|
for (i = 0; i < options.num_identity_files; i++) {
|
|
key = options.identity_keys[i];
|
|
if (key && key->type == KEY_RSA1)
|
|
continue;
|
|
options.identity_keys[i] = NULL;
|
|
id = xmalloc(sizeof(*id));
|
|
memset(id, 0, sizeof(*id));
|
|
id->key = key;
|
|
id->filename = xstrdup(options.identity_files[i]);
|
|
TAILQ_INSERT_TAIL(&files, id, next);
|
|
}
|
|
/* list of keys supported by the agent */
|
|
if ((ac = ssh_get_authentication_connection())) {
|
|
for (key = ssh_get_first_identity(ac, &comment, 2);
|
|
key != NULL;
|
|
key = ssh_get_next_identity(ac, &comment, 2)) {
|
|
found = 0;
|
|
TAILQ_FOREACH(id, &files, next) {
|
|
/* agent keys from the config file are preferred */
|
|
if (key_equal(key, id->key)) {
|
|
key_free(key);
|
|
xfree(comment);
|
|
TAILQ_REMOVE(&files, id, next);
|
|
TAILQ_INSERT_TAIL(preferred, id, next);
|
|
id->ac = ac;
|
|
found = 1;
|
|
break;
|
|
}
|
|
}
|
|
if (!found) {
|
|
id = xmalloc(sizeof(*id));
|
|
memset(id, 0, sizeof(*id));
|
|
id->key = key;
|
|
id->filename = comment;
|
|
id->ac = ac;
|
|
TAILQ_INSERT_TAIL(&agent, id, next);
|
|
}
|
|
}
|
|
/* append remaining agent keys */
|
|
for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) {
|
|
TAILQ_REMOVE(&agent, id, next);
|
|
TAILQ_INSERT_TAIL(preferred, id, next);
|
|
}
|
|
authctxt->agent = ac;
|
|
}
|
|
/* append remaining keys from the config file */
|
|
for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) {
|
|
TAILQ_REMOVE(&files, id, next);
|
|
TAILQ_INSERT_TAIL(preferred, id, next);
|
|
}
|
|
TAILQ_FOREACH(id, preferred, next) {
|
|
debug2("key: %s (%p)", id->filename, id->key);
|
|
}
|
|
}
|
|
|
|
static void
|
|
pubkey_cleanup(Authctxt *authctxt)
|
|
{
|
|
Identity *id;
|
|
|
|
if (authctxt->agent != NULL)
|
|
ssh_close_authentication_connection(authctxt->agent);
|
|
for (id = TAILQ_FIRST(&authctxt->keys); id;
|
|
id = TAILQ_FIRST(&authctxt->keys)) {
|
|
TAILQ_REMOVE(&authctxt->keys, id, next);
|
|
if (id->key)
|
|
key_free(id->key);
|
|
if (id->filename)
|
|
xfree(id->filename);
|
|
xfree(id);
|
|
}
|
|
}
|
|
|
|
int
|
|
userauth_pubkey(Authctxt *authctxt)
|
|
{
|
|
Identity *id;
|
|
int sent = 0;
|
|
|
|
while ((id = TAILQ_FIRST(&authctxt->keys))) {
|
|
if (id->tried++)
|
|
return (0);
|
|
TAILQ_REMOVE(&authctxt->keys, id, next);
|
|
TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
|
|
/*
|
|
* send a test message if we have the public key. for
|
|
* encrypted keys we cannot do this and have to load the
|
|
* private key instead
|
|
*/
|
|
if (id->key && id->key->type != KEY_RSA1) {
|
|
debug("Offering public key: %s", id->filename);
|
|
sent = send_pubkey_test(authctxt, id);
|
|
} else if (id->key == NULL) {
|
|
debug("Trying private key: %s", id->filename);
|
|
id->key = load_identity_file(id->filename);
|
|
if (id->key != NULL) {
|
|
id->isprivate = 1;
|
|
sent = sign_and_send_pubkey(authctxt, id);
|
|
key_free(id->key);
|
|
id->key = NULL;
|
|
}
|
|
}
|
|
if (sent)
|
|
return (sent);
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Send userauth request message specifying keyboard-interactive method.
|
|
*/
|
|
int
|
|
userauth_kbdint(Authctxt *authctxt)
|
|
{
|
|
static int attempt = 0;
|
|
|
|
if (attempt++ >= options.number_of_password_prompts)
|
|
return 0;
|
|
/* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
|
|
if (attempt > 1 && !authctxt->info_req_seen) {
|
|
debug3("userauth_kbdint: disable: no info_req_seen");
|
|
dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
|
|
return 0;
|
|
}
|
|
|
|
debug2("userauth_kbdint");
|
|
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(""); /* lang */
|
|
packet_put_cstring(options.kbd_interactive_devices ?
|
|
options.kbd_interactive_devices : "");
|
|
packet_send();
|
|
|
|
dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* parse INFO_REQUEST, prompt user and send INFO_RESPONSE
|
|
*/
|
|
void
|
|
input_userauth_info_req(int type, u_int32_t seq, void *ctxt)
|
|
{
|
|
Authctxt *authctxt = ctxt;
|
|
char *name, *inst, *lang, *prompt, *response;
|
|
u_int num_prompts, i;
|
|
int echo = 0;
|
|
|
|
debug2("input_userauth_info_req");
|
|
|
|
if (authctxt == NULL)
|
|
fatal("input_userauth_info_req: no authentication context");
|
|
|
|
authctxt->info_req_seen = 1;
|
|
|
|
name = packet_get_string(NULL);
|
|
inst = packet_get_string(NULL);
|
|
lang = packet_get_string(NULL);
|
|
if (strlen(name) > 0)
|
|
logit("%s", name);
|
|
if (strlen(inst) > 0)
|
|
logit("%s", inst);
|
|
xfree(name);
|
|
xfree(inst);
|
|
xfree(lang);
|
|
|
|
num_prompts = packet_get_int();
|
|
/*
|
|
* 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.
|
|
*/
|
|
packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE);
|
|
packet_put_int(num_prompts);
|
|
|
|
debug2("input_userauth_info_req: num_prompts %d", num_prompts);
|
|
for (i = 0; i < num_prompts; i++) {
|
|
prompt = packet_get_string(NULL);
|
|
echo = packet_get_char();
|
|
|
|
response = read_passphrase(prompt, echo ? RP_ECHO : 0);
|
|
|
|
packet_put_cstring(response);
|
|
memset(response, 0, strlen(response));
|
|
xfree(response);
|
|
xfree(prompt);
|
|
}
|
|
packet_check_eom(); /* done with parsing incoming message. */
|
|
|
|
packet_add_padding(64);
|
|
packet_send();
|
|
}
|
|
|
|
static int
|
|
ssh_keysign(Key *key, u_char **sigp, u_int *lenp,
|
|
u_char *data, u_int datalen)
|
|
{
|
|
Buffer b;
|
|
struct stat st;
|
|
pid_t pid;
|
|
int to[2], from[2], status, version = 2;
|
|
|
|
debug2("ssh_keysign called");
|
|
|
|
if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) {
|
|
error("ssh_keysign: no installed: %s", 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));
|
|
return -1;
|
|
}
|
|
if (pipe(from) < 0) {
|
|
error("ssh_keysign: pipe: %s", strerror(errno));
|
|
return -1;
|
|
}
|
|
if ((pid = fork()) < 0) {
|
|
error("ssh_keysign: fork: %s", strerror(errno));
|
|
return -1;
|
|
}
|
|
if (pid == 0) {
|
|
seteuid(getuid());
|
|
setuid(getuid());
|
|
close(from[0]);
|
|
if (dup2(from[1], STDOUT_FILENO) < 0)
|
|
fatal("ssh_keysign: dup2: %s", strerror(errno));
|
|
close(to[1]);
|
|
if (dup2(to[0], STDIN_FILENO) < 0)
|
|
fatal("ssh_keysign: dup2: %s", strerror(errno));
|
|
close(from[1]);
|
|
close(to[0]);
|
|
execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *) 0);
|
|
fatal("ssh_keysign: exec(%s): %s", _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);
|
|
ssh_msg_send(to[1], version, &b);
|
|
|
|
if (ssh_msg_recv(from[0], &b) < 0) {
|
|
error("ssh_keysign: no reply");
|
|
buffer_clear(&b);
|
|
return -1;
|
|
}
|
|
close(from[0]);
|
|
close(to[1]);
|
|
|
|
while (waitpid(pid, &status, 0) < 0)
|
|
if (errno != EINTR)
|
|
break;
|
|
|
|
if (buffer_get_char(&b) != version) {
|
|
error("ssh_keysign: bad version");
|
|
buffer_clear(&b);
|
|
return -1;
|
|
}
|
|
*sigp = buffer_get_string(&b, lenp);
|
|
buffer_clear(&b);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
userauth_hostbased(Authctxt *authctxt)
|
|
{
|
|
Key *private = NULL;
|
|
Sensitive *sensitive = authctxt->sensitive;
|
|
Buffer b;
|
|
u_char *signature, *blob;
|
|
char *chost, *pkalg, *p;
|
|
const char *service;
|
|
u_int blen, slen;
|
|
int ok, i, len, 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;
|
|
/* we take and free the key */
|
|
sensitive->keys[i] = NULL;
|
|
break;
|
|
}
|
|
}
|
|
if (!found) {
|
|
debug("No more client hostkeys for hostbased authentication.");
|
|
return 0;
|
|
}
|
|
if (key_to_blob(private, &blob, &blen) == 0) {
|
|
key_free(private);
|
|
return 0;
|
|
}
|
|
/* 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);
|
|
return 0;
|
|
}
|
|
len = strlen(p) + 2;
|
|
chost = xmalloc(len);
|
|
strlcpy(chost, p, len);
|
|
strlcat(chost, ".", len);
|
|
debug2("userauth_hostbased: chost %s", chost);
|
|
xfree(p);
|
|
|
|
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);
|
|
#ifdef DEBUG_PK
|
|
buffer_dump(&b);
|
|
#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");
|
|
xfree(chost);
|
|
xfree(pkalg);
|
|
return 0;
|
|
}
|
|
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);
|
|
memset(signature, 's', slen);
|
|
xfree(signature);
|
|
xfree(chost);
|
|
xfree(pkalg);
|
|
|
|
packet_send();
|
|
return 1;
|
|
}
|
|
|
|
/* 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);
|
|
if (supported != NULL)
|
|
xfree(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);
|
|
return current;
|
|
}
|
|
}
|
|
}
|
|
|
|
static char *
|
|
authmethods_get(void)
|
|
{
|
|
Authmethod *method = NULL;
|
|
Buffer b;
|
|
char *list;
|
|
|
|
buffer_init(&b);
|
|
for (method = authmethods; method->name != NULL; method++) {
|
|
if (authmethod_is_enabled(method)) {
|
|
if (buffer_len(&b) > 0)
|
|
buffer_append(&b, ",", 1);
|
|
buffer_append(&b, method->name, strlen(method->name));
|
|
}
|
|
}
|
|
buffer_append(&b, "\0", 1);
|
|
list = xstrdup(buffer_ptr(&b));
|
|
buffer_free(&b);
|
|
return list;
|
|
}
|