+/* $OpenBSD: sshconnect2.c,v 1.177 2010/01/04 01:45:30 dtucker 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
*/
#include "includes.h"
-RCSID("$OpenBSD: sshconnect2.c,v 1.31 2000/12/15 17:30:14 provos Exp $");
-#include <openssl/bn.h>
-#include <openssl/rsa.h>
-#include <openssl/dsa.h>
-#include <openssl/md5.h>
-#include <openssl/dh.h>
-#include <openssl/hmac.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/wait.h>
+#include <sys/stat.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <netdb.h>
+#include <pwd.h>
+#include <signal.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#if defined(HAVE_STRNVIS) && defined(HAVE_VIS_H)
+#include <vis.h>
+#endif
+
+#include "openbsd-compat/sys-queue.h"
-#include "ssh.h"
#include "xmalloc.h"
-#include "rsa.h"
+#include "ssh.h"
+#include "ssh2.h"
#include "buffer.h"
#include "packet.h"
-#include "uidswap.h"
#include "compat.h"
-#include "readconf.h"
-#include "bufaux.h"
-#include "ssh2.h"
+#include "cipher.h"
+#include "key.h"
#include "kex.h"
#include "myproposal.h"
-#include "key.h"
#include "sshconnect.h"
#include "authfile.h"
-#include "cli.h"
-#include "dispatch.h"
+#include "dh.h"
#include "authfd.h"
+#include "log.h"
+#include "readconf.h"
+#include "misc.h"
+#include "match.h"
+#include "dispatch.h"
+#include "canohost.h"
+#include "msg.h"
+#include "pathnames.h"
+#include "uidswap.h"
+#include "schnorr.h"
+#include "jpake.h"
-void ssh_dh1_client(Kex *, char *, struct sockaddr *, Buffer *, Buffer *);
-void ssh_dhgex_client(Kex *, char *, struct sockaddr *, Buffer *, Buffer *);
+#ifdef GSSAPI
+#include "ssh-gss.h"
+#endif
/* import */
extern char *client_version_string;
* SSH2 key exchange
*/
-unsigned char *session_id2 = NULL;
-int session_id2_len = 0;
+u_char *session_id2 = NULL;
+u_int session_id2_len = 0;
+
+char *xxx_host;
+struct sockaddr *xxx_hostaddr;
+
+Kex *xxx_kex = NULL;
+
+static int
+verify_host_key_callback(Key *hostkey)
+{
+ if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1)
+ fatal("Host key verification failed.");
+ return 0;
+}
void
ssh_kex2(char *host, struct sockaddr *hostaddr)
{
- int i, plen;
Kex *kex;
- Buffer *client_kexinit, *server_kexinit;
- char *sprop[PROPOSAL_MAX];
+
+ xxx_host = host;
+ xxx_hostaddr = hostaddr;
if (options.ciphers == (char *)-1) {
- log("No valid ciphers for protocol version 2 given, using defaults.");
+ logit("No valid ciphers for protocol version 2 given, using defaults.");
options.ciphers = NULL;
}
if (options.ciphers != NULL) {
myproposal[PROPOSAL_ENC_ALGS_CTOS] =
myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
}
+ myproposal[PROPOSAL_ENC_ALGS_CTOS] =
+ compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]);
+ myproposal[PROPOSAL_ENC_ALGS_STOC] =
+ compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]);
if (options.compression) {
- myproposal[PROPOSAL_COMP_ALGS_CTOS] = "zlib";
- myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib";
+ myproposal[PROPOSAL_COMP_ALGS_CTOS] =
+ myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib@openssh.com,zlib,none";
} else {
- myproposal[PROPOSAL_COMP_ALGS_CTOS] = "none";
- myproposal[PROPOSAL_COMP_ALGS_STOC] = "none";
+ myproposal[PROPOSAL_COMP_ALGS_CTOS] =
+ myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib@openssh.com,zlib";
}
-
- /* buffers with raw kexinit messages */
- server_kexinit = xmalloc(sizeof(*server_kexinit));
- buffer_init(server_kexinit);
- client_kexinit = kex_init(myproposal);
-
- /* algorithm negotiation */
- kex_exchange_kexinit(client_kexinit, server_kexinit, sprop);
- kex = kex_choose_conf(myproposal, sprop, 0);
- for (i = 0; i < PROPOSAL_MAX; i++)
- xfree(sprop[i]);
-
- /* server authentication and session key agreement */
- switch(kex->kex_type) {
- case DH_GRP1_SHA1:
- ssh_dh1_client(kex, host, hostaddr,
- client_kexinit, server_kexinit);
- break;
- case DH_GEX_SHA1:
- ssh_dhgex_client(kex, host, hostaddr, client_kexinit,
- server_kexinit);
- break;
- default:
- fatal("Unsupported key exchange %d", kex->kex_type);
+ if (options.macs != NULL) {
+ myproposal[PROPOSAL_MAC_ALGS_CTOS] =
+ myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
+ }
+ if (options.hostkeyalgorithms != NULL)
+ myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
+ options.hostkeyalgorithms;
+
+ if (options.rekey_limit)
+ packet_set_rekey_limit((u_int32_t)options.rekey_limit);
+
+ /* start key exchange */
+ kex = kex_setup(myproposal);
+ kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
+ kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
+ kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
+ kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
+ kex->client_version_string=client_version_string;
+ kex->server_version_string=server_version_string;
+ kex->verify_host_key=&verify_host_key_callback;
+
+ xxx_kex = kex;
+
+ dispatch_run(DISPATCH_BLOCK, &kex->done, kex);
+
+ if (options.use_roaming && !kex->roaming) {
+ debug("Roaming not allowed by server");
+ options.use_roaming = 0;
}
- buffer_free(client_kexinit);
- buffer_free(server_kexinit);
- xfree(client_kexinit);
- xfree(server_kexinit);
-
- debug("Wait SSH2_MSG_NEWKEYS.");
- packet_read_expect(&plen, SSH2_MSG_NEWKEYS);
- packet_done();
- debug("GOT SSH2_MSG_NEWKEYS.");
-
- debug("send SSH2_MSG_NEWKEYS.");
- packet_start(SSH2_MSG_NEWKEYS);
- packet_send();
- packet_write_wait();
- debug("done: send SSH2_MSG_NEWKEYS.");
+ session_id2 = kex->session_id;
+ session_id2_len = kex->session_id_len;
#ifdef DEBUG_KEXDH
/* send 1st encrypted/maced/compressed message */
packet_send();
packet_write_wait();
#endif
- debug("done: KEX2.");
}
-/* diffie-hellman-group1-sha1 */
+/*
+ * Authenticate user
+ */
+
+typedef struct Authctxt Authctxt;
+typedef struct Authmethod Authmethod;
+typedef struct identity Identity;
+typedef struct idlist Idlist;
+
+struct identity {
+ TAILQ_ENTRY(identity) next;
+ AuthenticationConnection *ac; /* set if agent supports key */
+ Key *key; /* public/private key */
+ char *filename; /* comment for agent-only keys */
+ int tried;
+ int isprivate; /* key points to the private key */
+};
+TAILQ_HEAD(idlist, identity);
+
+struct Authctxt {
+ const char *server_user;
+ const char *local_user;
+ const char *host;
+ const char *service;
+ Authmethod *method;
+ int success;
+ char *authlist;
+ /* pubkey */
+ Idlist keys;
+ AuthenticationConnection *agent;
+ /* hostbased */
+ Sensitive *sensitive;
+ /* kbd-interactive */
+ int info_req_seen;
+ /* generic */
+ void *methoddata;
+};
+struct Authmethod {
+ char *name; /* string to compare against server's list */
+ int (*userauth)(Authctxt *authctxt);
+ void (*cleanup)(Authctxt *authctxt);
+ int *enabled; /* flag in option struct that enables method */
+ int *batch_flag; /* flag in option struct that disables method */
+};
+
+void input_userauth_success(int, u_int32_t, void *);
+void input_userauth_success_unexpected(int, u_int32_t, void *);
+void input_userauth_failure(int, u_int32_t, void *);
+void input_userauth_banner(int, u_int32_t, void *);
+void input_userauth_error(int, u_int32_t, void *);
+void input_userauth_info_req(int, u_int32_t, void *);
+void input_userauth_pk_ok(int, u_int32_t, void *);
+void input_userauth_passwd_changereq(int, u_int32_t, void *);
+void input_userauth_jpake_server_step1(int, u_int32_t, void *);
+void input_userauth_jpake_server_step2(int, u_int32_t, void *);
+void input_userauth_jpake_server_confirm(int, u_int32_t, void *);
+
+int userauth_none(Authctxt *);
+int userauth_pubkey(Authctxt *);
+int userauth_passwd(Authctxt *);
+int userauth_kbdint(Authctxt *);
+int userauth_hostbased(Authctxt *);
+int userauth_jpake(Authctxt *);
+
+void userauth_jpake_cleanup(Authctxt *);
+
+#ifdef GSSAPI
+int userauth_gssapi(Authctxt *authctxt);
+void input_gssapi_response(int type, u_int32_t, void *);
+void input_gssapi_token(int type, u_int32_t, void *);
+void input_gssapi_hash(int type, u_int32_t, void *);
+void input_gssapi_error(int, u_int32_t, void *);
+void input_gssapi_errtok(int, u_int32_t, void *);
+#endif
+
+void userauth(Authctxt *, char *);
+
+static int sign_and_send_pubkey(Authctxt *, Identity *);
+static void pubkey_prepare(Authctxt *);
+static void pubkey_cleanup(Authctxt *);
+static Key *load_identity_file(char *);
+
+static Authmethod *authmethod_get(char *authlist);
+static Authmethod *authmethod_lookup(const char *name);
+static char *authmethods_get(void);
+
+Authmethod authmethods[] = {
+#ifdef GSSAPI
+ {"gssapi-with-mic",
+ userauth_gssapi,
+ NULL,
+ &options.gss_authentication,
+ NULL},
+#endif
+ {"hostbased",
+ userauth_hostbased,
+ NULL,
+ &options.hostbased_authentication,
+ NULL},
+ {"publickey",
+ userauth_pubkey,
+ NULL,
+ &options.pubkey_authentication,
+ NULL},
+#ifdef JPAKE
+ {"jpake-01@openssh.com",
+ userauth_jpake,
+ userauth_jpake_cleanup,
+ &options.zero_knowledge_password_authentication,
+ &options.batch_mode},
+#endif
+ {"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_dh1_client(Kex *kex, char *host, struct sockaddr *hostaddr,
- Buffer *client_kexinit, Buffer *server_kexinit)
+ssh_userauth2(const char *local_user, const char *server_user, char *host,
+ Sensitive *sensitive)
{
-#ifdef DEBUG_KEXDH
- int i;
-#endif
- int plen, dlen;
- unsigned int klen, kout;
- char *signature = NULL;
- unsigned int slen;
- char *server_host_key_blob = NULL;
- Key *server_host_key;
- unsigned int sbloblen;
- DH *dh;
- BIGNUM *dh_server_pub = 0;
- BIGNUM *shared_secret = 0;
- unsigned char *kbuf;
- unsigned char *hash;
-
- debug("Sending SSH2_MSG_KEXDH_INIT.");
- /* generate and send 'e', client DH public key */
- dh = dh_new_group1();
- dh_gen_key(dh);
- packet_start(SSH2_MSG_KEXDH_INIT);
- packet_put_bignum2(dh->pub_key);
+ Authctxt authctxt;
+ int type;
+
+ if (options.challenge_response_authentication)
+ options.kbd_interactive_authentication = 1;
+
+ packet_start(SSH2_MSG_SERVICE_REQUEST);
+ packet_put_cstring("ssh-userauth");
packet_send();
+ debug("SSH2_MSG_SERVICE_REQUEST sent");
packet_write_wait();
+ type = packet_read();
+ if (type != SSH2_MSG_SERVICE_ACCEPT)
+ fatal("Server denied authentication request: %d", type);
+ if (packet_remaining() > 0) {
+ char *reply = packet_get_string(NULL);
+ debug2("service_accept: %s", reply);
+ xfree(reply);
+ } else {
+ debug2("buggy server: service_accept w/o service");
+ }
+ packet_check_eom();
+ debug("SSH2_MSG_SERVICE_ACCEPT received");
-#ifdef DEBUG_KEXDH
- fprintf(stderr, "\np= ");
- BN_print_fp(stderr, dh->p);
- fprintf(stderr, "\ng= ");
- BN_print_fp(stderr, dh->g);
- fprintf(stderr, "\npub= ");
- BN_print_fp(stderr, dh->pub_key);
- fprintf(stderr, "\n");
- DHparams_print_fp(stderr, dh);
-#endif
+ if (options.preferred_authentications == NULL)
+ options.preferred_authentications = authmethods_get();
- debug("Wait SSH2_MSG_KEXDH_REPLY.");
+ /* setup authentication context */
+ memset(&authctxt, 0, sizeof(authctxt));
+ pubkey_prepare(&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.info_req_seen = 0;
+ if (authctxt.method == NULL)
+ fatal("ssh_userauth2: internal error: cannot send userauth none request");
- packet_read_expect(&plen, SSH2_MSG_KEXDH_REPLY);
+ /* initial userauth request */
+ userauth_none(&authctxt);
- debug("Got SSH2_MSG_KEXDH_REPLY.");
+ dispatch_init(&input_userauth_error);
+ dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
+ dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
+ dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
+ dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */
- /* key, cert */
- server_host_key_blob = packet_get_string(&sbloblen);
- server_host_key = key_from_blob(server_host_key_blob, sbloblen);
- if (server_host_key == NULL)
- fatal("cannot decode server_host_key_blob");
+ pubkey_cleanup(&authctxt);
+ dispatch_range(SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
- check_host_key(host, hostaddr, server_host_key,
- options.user_hostfile2, options.system_hostfile2);
+ debug("Authentication succeeded (%s).", authctxt.method->name);
+}
- /* DH paramter f, server public DH key */
- dh_server_pub = BN_new();
- if (dh_server_pub == NULL)
- fatal("dh_server_pub == NULL");
- packet_get_bignum2(dh_server_pub, &dlen);
+void
+userauth(Authctxt *authctxt, char *authlist)
+{
+ if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
+ authctxt->method->cleanup(authctxt);
-#ifdef DEBUG_KEXDH
- fprintf(stderr, "\ndh_server_pub= ");
- BN_print_fp(stderr, dh_server_pub);
- fprintf(stderr, "\n");
- debug("bits %d", BN_num_bits(dh_server_pub));
-#endif
+ if (authctxt->methoddata) {
+ xfree(authctxt->methoddata);
+ authctxt->methoddata = NULL;
+ }
+ if (authlist == NULL) {
+ authlist = authctxt->authlist;
+ } else {
+ if (authctxt->authlist)
+ xfree(authctxt->authlist);
+ authctxt->authlist = authlist;
+ }
+ for (;;) {
+ Authmethod *method = authmethod_get(authlist);
+ if (method == NULL)
+ fatal("Permission denied (%s).", authlist);
+ authctxt->method = method;
- /* signed H */
- signature = packet_get_string(&slen);
- packet_done();
+ /* reset the per method handler */
+ dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN,
+ SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
- if (!dh_pub_is_valid(dh, dh_server_pub))
- packet_disconnect("bad server public DH value");
+ /* and try new method */
+ if (method->userauth(authctxt) != 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;
+ }
+ }
+}
- klen = DH_size(dh);
- kbuf = xmalloc(klen);
- kout = DH_compute_key(kbuf, dh_server_pub, dh);
-#ifdef DEBUG_KEXDH
- debug("shared secret: len %d/%d", klen, kout);
- fprintf(stderr, "shared secret == ");
- for (i = 0; i< kout; i++)
- fprintf(stderr, "%02x", (kbuf[i])&0xff);
- fprintf(stderr, "\n");
-#endif
- shared_secret = BN_new();
-
- BN_bin2bn(kbuf, kout, shared_secret);
- memset(kbuf, 0, klen);
- xfree(kbuf);
-
- /* calc and verify H */
- hash = kex_hash(
- client_version_string,
- server_version_string,
- buffer_ptr(client_kexinit), buffer_len(client_kexinit),
- buffer_ptr(server_kexinit), buffer_len(server_kexinit),
- server_host_key_blob, sbloblen,
- dh->pub_key,
- dh_server_pub,
- shared_secret
- );
- xfree(server_host_key_blob);
- DH_free(dh);
-#ifdef DEBUG_KEXDH
- fprintf(stderr, "hash == ");
- for (i = 0; i< 20; i++)
- fprintf(stderr, "%02x", (hash[i])&0xff);
- fprintf(stderr, "\n");
-#endif
- if (key_verify(server_host_key, (unsigned char *)signature, slen, hash, 20) != 1)
- fatal("key_verify failed for server_host_key");
- key_free(server_host_key);
+/* ARGSUSED */
+void
+input_userauth_error(int type, u_int32_t seq, void *ctxt)
+{
+ fatal("input_userauth_error: bad message during authentication: "
+ "type %d", type);
+}
- kex_derive_keys(kex, hash, shared_secret);
- packet_set_kex(kex);
+/* ARGSUSED */
+void
+input_userauth_banner(int type, u_int32_t seq, void *ctxt)
+{
+ char *msg, *raw, *lang;
+ u_int len;
- /* save session id */
- session_id2_len = 20;
- session_id2 = xmalloc(session_id2_len);
- memcpy(session_id2, hash, session_id2_len);
+ debug3("input_userauth_banner");
+ raw = packet_get_string(&len);
+ lang = packet_get_string(NULL);
+ if (len > 0 && options.log_level >= SYSLOG_LEVEL_INFO) {
+ if (len > 65536)
+ len = 65536;
+ msg = xmalloc(len * 4 + 1); /* max expansion from strnvis() */
+ strnvis(msg, raw, len * 4 + 1, VIS_SAFE|VIS_OCTAL|VIS_NOSLASH);
+ fprintf(stderr, "%s", msg);
+ xfree(msg);
+ }
+ xfree(raw);
+ xfree(lang);
}
-/* diffie-hellman-group-exchange-sha1 */
+/* ARGSUSED */
+void
+input_userauth_success(int type, u_int32_t seq, void *ctxt)
+{
+ Authctxt *authctxt = ctxt;
-/*
- * Estimates the group order for a Diffie-Hellman group that has an
- * attack complexity approximately the same as O(2**bits). Estimate
- * with: O(exp(1.9223 * (ln q)^(1/3) (ln ln q)^(2/3)))
- */
+ if (authctxt == NULL)
+ fatal("input_userauth_success: no authentication context");
+ if (authctxt->authlist) {
+ xfree(authctxt->authlist);
+ authctxt->authlist = NULL;
+ }
+ if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
+ authctxt->method->cleanup(authctxt);
+ if (authctxt->methoddata) {
+ xfree(authctxt->methoddata);
+ authctxt->methoddata = NULL;
+ }
+ authctxt->success = 1; /* break out */
+}
-int
-dh_estimate(int bits)
+void
+input_userauth_success_unexpected(int type, u_int32_t seq, void *ctxt)
{
-
- if (bits < 64)
- return (512); /* O(2**63) */
- if (bits < 128)
- return (1024); /* O(2**86) */
- if (bits < 192)
- return (2048); /* O(2**116) */
- return (4096); /* O(2**156) */
+ Authctxt *authctxt = ctxt;
+
+ if (authctxt == NULL)
+ fatal("%s: no authentication context", __func__);
+
+ fatal("Unexpected authentication success during %s.",
+ authctxt->method->name);
}
+/* ARGSUSED */
void
-ssh_dhgex_client(Kex *kex, char *host, struct sockaddr *hostaddr,
- Buffer *client_kexinit, Buffer *server_kexinit)
+input_userauth_failure(int type, u_int32_t seq, void *ctxt)
{
-#ifdef DEBUG_KEXDH
- int i;
-#endif
- int plen, dlen;
- unsigned int klen, kout;
- char *signature = NULL;
- unsigned int slen, nbits;
- char *server_host_key_blob = NULL;
- Key *server_host_key;
- unsigned int sbloblen;
- DH *dh;
- BIGNUM *dh_server_pub = 0;
- BIGNUM *shared_secret = 0;
- BIGNUM *p = 0, *g = 0;
- unsigned char *kbuf;
- unsigned char *hash;
-
- nbits = dh_estimate(kex->enc[MODE_OUT].cipher->key_len * 8);
-
- debug("Sending SSH2_MSG_KEX_DH_GEX_REQUEST.");
- packet_start(SSH2_MSG_KEX_DH_GEX_REQUEST);
- packet_put_int(nbits);
- packet_send();
- packet_write_wait();
+ Authctxt *authctxt = ctxt;
+ char *authlist = NULL;
+ int partial;
-#ifdef DEBUG_KEXDH
- fprintf(stderr, "\nnbits = %d", nbits);
-#endif
+ if (authctxt == NULL)
+ fatal("input_userauth_failure: no authentication context");
- debug("Wait SSH2_MSG_KEX_DH_GEX_GROUP.");
+ authlist = packet_get_string(NULL);
+ partial = packet_get_char();
+ packet_check_eom();
- packet_read_expect(&plen, SSH2_MSG_KEX_DH_GEX_GROUP);
+ if (partial != 0)
+ logit("Authenticated with partial success.");
+ debug("Authentications that can continue: %s", authlist);
- debug("Got SSH2_MSG_KEX_DH_GEX_GROUP.");
+ userauth(authctxt, authlist);
+}
- if ((p = BN_new()) == NULL)
- fatal("BN_new");
- packet_get_bignum2(p, &dlen);
- if ((g = BN_new()) == NULL)
- fatal("BN_new");
- packet_get_bignum2(g, &dlen);
- if ((dh = dh_new_group(g, p)) == NULL)
- fatal("dh_new_group");
+/* ARGSUSED */
+void
+input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt)
+{
+ Authctxt *authctxt = ctxt;
+ Key *key = NULL;
+ Identity *id = NULL;
+ Buffer b;
+ int pktype, sent = 0;
+ u_int alen, blen;
+ char *pkalg, *fp;
+ u_char *pkblob;
- dh_gen_key(dh);
+ if (authctxt == NULL)
+ fatal("input_userauth_pk_ok: no authentication context");
+ if (datafellows & SSH_BUG_PKOK) {
+ /* this is similar to SSH_BUG_PKAUTH */
+ debug2("input_userauth_pk_ok: SSH_BUG_PKOK");
+ pkblob = packet_get_string(&blen);
+ buffer_init(&b);
+ buffer_append(&b, pkblob, blen);
+ pkalg = buffer_get_string(&b, &alen);
+ buffer_free(&b);
+ } else {
+ pkalg = packet_get_string(&alen);
+ pkblob = packet_get_string(&blen);
+ }
+ packet_check_eom();
-#ifdef DEBUG_KEXDH
- fprintf(stderr, "\np= ");
- BN_print_fp(stderr, dh->p);
- fprintf(stderr, "\ng= ");
- BN_print_fp(stderr, dh->g);
- fprintf(stderr, "\npub= ");
- BN_print_fp(stderr, dh->pub_key);
- fprintf(stderr, "\n");
- DHparams_print_fp(stderr, dh);
-#endif
+ debug("Server accepts key: pkalg %s blen %u", pkalg, blen);
+
+ if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) {
+ debug("unknown pkalg %s", pkalg);
+ goto done;
+ }
+ if ((key = key_from_blob(pkblob, blen)) == NULL) {
+ debug("no key from blob. pkalg %s", pkalg);
+ goto done;
+ }
+ if (key->type != pktype) {
+ error("input_userauth_pk_ok: type mismatch "
+ "for decoded key (received %d, expected %d)",
+ key->type, pktype);
+ goto done;
+ }
+ fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX);
+ debug2("input_userauth_pk_ok: fp %s", fp);
+ xfree(fp);
+
+ /*
+ * 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 (key_equal(key, id->key)) {
+ sent = sign_and_send_pubkey(authctxt, id);
+ break;
+ }
+ }
+done:
+ if (key != NULL)
+ key_free(key);
+ xfree(pkalg);
+ xfree(pkblob);
+
+ /* try another method if we did not send a packet */
+ if (sent == 0)
+ userauth(authctxt, NULL);
+}
+
+#ifdef GSSAPI
+int
+userauth_gssapi(Authctxt *authctxt)
+{
+ Gssctxt *gssctxt = NULL;
+ static gss_OID_set gss_supported = NULL;
+ static u_int mech = 0;
+ OM_uint32 min;
+ int ok = 0;
+
+ /* Try one GSSAPI method at a time, rather than sending them all at
+ * once. */
+
+ if (gss_supported == NULL)
+ gss_indicate_mechs(&min, &gss_supported);
+
+ /* Check to see if the mechanism is usable before we offer it */
+ while (mech < gss_supported->count && !ok) {
+ /* My DER encoding requires length<128 */
+ if (gss_supported->elements[mech].length < 128 &&
+ ssh_gssapi_check_mechanism(&gssctxt,
+ &gss_supported->elements[mech], authctxt->host)) {
+ ok = 1; /* Mechanism works */
+ } else {
+ mech++;
+ }
+ }
+
+ if (!ok)
+ return 0;
+
+ authctxt->methoddata=(void *)gssctxt;
+
+ packet_start(SSH2_MSG_USERAUTH_REQUEST);
+ packet_put_cstring(authctxt->server_user);
+ packet_put_cstring(authctxt->service);
+ packet_put_cstring(authctxt->method->name);
+
+ packet_put_int(1);
+
+ packet_put_int((gss_supported->elements[mech].length) + 2);
+ packet_put_char(SSH_GSS_OIDTYPE);
+ packet_put_char(gss_supported->elements[mech].length);
+ packet_put_raw(gss_supported->elements[mech].elements,
+ gss_supported->elements[mech].length);
- debug("Sending SSH2_MSG_KEX_DH_GEX_INIT.");
- /* generate and send 'e', client DH public key */
- packet_start(SSH2_MSG_KEX_DH_GEX_INIT);
- packet_put_bignum2(dh->pub_key);
packet_send();
- packet_write_wait();
- debug("Wait SSH2_MSG_KEX_DH_GEX_REPLY.");
+ 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);
- packet_read_expect(&plen, SSH2_MSG_KEX_DH_GEX_REPLY);
+ mech++; /* Move along to next candidate */
- debug("Got SSH2_MSG_KEXDH_REPLY.");
+ return 1;
+}
- /* key, cert */
- server_host_key_blob = packet_get_string(&sbloblen);
- server_host_key = key_from_blob(server_host_key_blob, sbloblen);
- if (server_host_key == NULL)
- fatal("cannot decode server_host_key_blob");
+static OM_uint32
+process_gssapi_token(void *ctxt, gss_buffer_t recv_tok)
+{
+ Authctxt *authctxt = ctxt;
+ 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;
+ Buffer b;
- check_host_key(host, hostaddr, server_host_key,
- options.user_hostfile2, options.system_hostfile2);
+ status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
+ recv_tok, &send_tok, &flags);
- /* DH paramter f, server public DH key */
- dh_server_pub = BN_new();
- if (dh_server_pub == NULL)
- fatal("dh_server_pub == NULL");
- packet_get_bignum2(dh_server_pub, &dlen);
+ if (send_tok.length > 0) {
+ if (GSS_ERROR(status))
+ packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
+ else
+ packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
-#ifdef DEBUG_KEXDH
- fprintf(stderr, "\ndh_server_pub= ");
- BN_print_fp(stderr, dh_server_pub);
- fprintf(stderr, "\n");
- debug("bits %d", BN_num_bits(dh_server_pub));
-#endif
+ packet_put_string(send_tok.value, send_tok.length);
+ packet_send();
+ gss_release_buffer(&ms, &send_tok);
+ }
- /* signed H */
- signature = packet_get_string(&slen);
- packet_done();
+ if (status == GSS_S_COMPLETE) {
+ /* send either complete or MIC, depending on mechanism */
+ if (!(flags & GSS_C_INTEG_FLAG)) {
+ packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE);
+ packet_send();
+ } else {
+ ssh_gssapi_buildmic(&b, authctxt->server_user,
+ authctxt->service, "gssapi-with-mic");
- if (!dh_pub_is_valid(dh, dh_server_pub))
- packet_disconnect("bad server public DH value");
+ gssbuf.value = buffer_ptr(&b);
+ gssbuf.length = buffer_len(&b);
- klen = DH_size(dh);
- kbuf = xmalloc(klen);
- kout = DH_compute_key(kbuf, dh_server_pub, dh);
-#ifdef DEBUG_KEXDH
- debug("shared secret: len %d/%d", klen, kout);
- fprintf(stderr, "shared secret == ");
- for (i = 0; i< kout; i++)
- fprintf(stderr, "%02x", (kbuf[i])&0xff);
- fprintf(stderr, "\n");
-#endif
- shared_secret = BN_new();
-
- BN_bin2bn(kbuf, kout, shared_secret);
- memset(kbuf, 0, klen);
- xfree(kbuf);
-
- /* calc and verify H */
- hash = kex_hash_gex(
- client_version_string,
- server_version_string,
- buffer_ptr(client_kexinit), buffer_len(client_kexinit),
- buffer_ptr(server_kexinit), buffer_len(server_kexinit),
- server_host_key_blob, sbloblen,
- nbits, dh->p, dh->g,
- dh->pub_key,
- dh_server_pub,
- shared_secret
- );
- xfree(server_host_key_blob);
- DH_free(dh);
-#ifdef DEBUG_KEXDH
- fprintf(stderr, "hash == ");
- for (i = 0; i< 20; i++)
- fprintf(stderr, "%02x", (hash[i])&0xff);
- fprintf(stderr, "\n");
-#endif
- if (key_verify(server_host_key, (unsigned char *)signature, slen, hash, 20) != 1)
- fatal("key_verify failed for server_host_key");
- key_free(server_host_key);
+ status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
+
+ if (!GSS_ERROR(status)) {
+ packet_start(SSH2_MSG_USERAUTH_GSSAPI_MIC);
+ packet_put_string(mic.value, mic.length);
- kex_derive_keys(kex, hash, shared_secret);
- packet_set_kex(kex);
+ packet_send();
+ }
+
+ buffer_free(&b);
+ gss_release_buffer(&ms, &mic);
+ }
+ }
- /* save session id */
- session_id2_len = 20;
- session_id2 = xmalloc(session_id2_len);
- memcpy(session_id2, hash, session_id2_len);
+ return status;
}
-/*
- * Authenticate user
- */
+/* ARGSUSED */
+void
+input_gssapi_response(int type, u_int32_t plen, void *ctxt)
+{
+ Authctxt *authctxt = ctxt;
+ Gssctxt *gssctxt;
+ int oidlen;
+ char *oidv;
-typedef struct Authctxt Authctxt;
-typedef struct Authmethod Authmethod;
+ if (authctxt == NULL)
+ fatal("input_gssapi_response: no authentication context");
+ gssctxt = authctxt->methoddata;
+
+ /* Setup our OID */
+ oidv = packet_get_string(&oidlen);
+
+ if (oidlen <= 2 ||
+ oidv[0] != SSH_GSS_OIDTYPE ||
+ oidv[1] != oidlen - 2) {
+ xfree(oidv);
+ debug("Badly encoded mechanism OID received");
+ userauth(authctxt, NULL);
+ return;
+ }
-typedef int sign_cb_fn(
- Authctxt *authctxt, Key *key,
- unsigned char **sigp, int *lenp, unsigned char *data, int datalen);
+ if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
+ fatal("Server returned different OID than expected");
-struct Authctxt {
- const char *server_user;
- const char *host;
- const char *service;
- AuthenticationConnection *agent;
- Authmethod *method;
- int success;
-};
-struct Authmethod {
- char *name; /* string to compare against server's list */
- int (*userauth)(Authctxt *authctxt);
- int *enabled; /* flag in option struct that enables method */
- int *batch_flag; /* flag in option struct that disables method */
-};
+ packet_check_eom();
-void input_userauth_success(int type, int plen, void *ctxt);
-void input_userauth_failure(int type, int plen, void *ctxt);
-void input_userauth_error(int type, int plen, void *ctxt);
-void input_userauth_info_req(int type, int plen, void *ctxt);
+ xfree(oidv);
-int userauth_none(Authctxt *authctxt);
-int userauth_pubkey(Authctxt *authctxt);
-int userauth_passwd(Authctxt *authctxt);
-int userauth_kbdint(Authctxt *authctxt);
+ if (GSS_ERROR(process_gssapi_token(ctxt, GSS_C_NO_BUFFER))) {
+ /* Start again with next method on list */
+ debug("Trying to start again");
+ userauth(authctxt, NULL);
+ return;
+ }
+}
-void authmethod_clear();
-Authmethod *authmethod_get(char *authlist);
-Authmethod *authmethod_lookup(const char *name);
+/* ARGSUSED */
+void
+input_gssapi_token(int type, u_int32_t plen, void *ctxt)
+{
+ Authctxt *authctxt = ctxt;
+ gss_buffer_desc recv_tok;
+ OM_uint32 status;
+ u_int slen;
-Authmethod authmethods[] = {
- {"publickey",
- userauth_pubkey,
- &options.pubkey_authentication,
- NULL},
- {"password",
- userauth_passwd,
- &options.password_authentication,
- &options.batch_mode},
- {"keyboard-interactive",
- userauth_kbdint,
- &options.kbd_interactive_authentication,
- &options.batch_mode},
- {"none",
- userauth_none,
- NULL,
- NULL},
- {NULL, NULL, NULL, NULL}
-};
+ if (authctxt == NULL)
+ fatal("input_gssapi_response: no authentication context");
+
+ recv_tok.value = packet_get_string(&slen);
+ recv_tok.length = slen; /* safe typecast */
+
+ packet_check_eom();
+
+ status = process_gssapi_token(ctxt, &recv_tok);
+ xfree(recv_tok.value);
+
+ if (GSS_ERROR(status)) {
+ /* Start again with the next method in the list */
+ userauth(authctxt, NULL);
+ return;
+ }
+}
+
+/* ARGSUSED */
void
-ssh_userauth2(const char *server_user, char *host)
+input_gssapi_errtok(int type, u_int32_t plen, void *ctxt)
{
- Authctxt authctxt;
- int type;
- int plen;
+ 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;
- debug("send SSH2_MSG_SERVICE_REQUEST");
- packet_start(SSH2_MSG_SERVICE_REQUEST);
- packet_put_cstring("ssh-userauth");
+ 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 */
+}
+
+/* ARGSUSED */
+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", 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();
- packet_write_wait();
- type = packet_read(&plen);
- if (type != SSH2_MSG_SERVICE_ACCEPT) {
- fatal("denied SSH2_MSG_SERVICE_ACCEPT: %d", type);
+ return 1;
+}
+
+int
+userauth_passwd(Authctxt *authctxt)
+{
+ static int attempt = 0;
+ char prompt[150];
+ char *password;
+ const char *host = options.host_key_alias ? options.host_key_alias :
+ authctxt->host;
+
+ 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, 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
+ */
+/* ARGSUSED */
+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];
+ const char *host = options.host_key_alias ? options.host_key_alias :
+ authctxt->host;
+
+ 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, 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, 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, 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);
}
- if (packet_remaining() > 0) {
- char *reply = packet_get_string(&plen);
- debug("service_accept: %s", reply);
- xfree(reply);
- packet_done();
- } else {
- debug("buggy server: service_accept w/o service");
+ 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);
+}
+
+#ifdef JPAKE
+static char *
+pw_encrypt(const char *password, const char *crypt_scheme, const char *salt)
+{
+ /* OpenBSD crypt(3) handles all of these */
+ if (strcmp(crypt_scheme, "crypt") == 0 ||
+ strcmp(crypt_scheme, "bcrypt") == 0 ||
+ strcmp(crypt_scheme, "md5crypt") == 0 ||
+ strcmp(crypt_scheme, "crypt-extended") == 0)
+ return xstrdup(crypt(password, salt));
+ error("%s: unsupported password encryption scheme \"%.100s\"",
+ __func__, crypt_scheme);
+ return NULL;
+}
+
+static BIGNUM *
+jpake_password_to_secret(Authctxt *authctxt, const char *crypt_scheme,
+ const char *salt)
+{
+ char prompt[256], *password, *crypted;
+ u_char *secret;
+ u_int secret_len;
+ BIGNUM *ret;
+
+ snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password (JPAKE): ",
+ authctxt->server_user, authctxt->host);
+ password = read_passphrase(prompt, 0);
+
+ if ((crypted = pw_encrypt(password, crypt_scheme, salt)) == NULL) {
+ logit("Disabling %s authentication", authctxt->method->name);
+ authctxt->method->enabled = NULL;
+ /* Continue with an empty password to fail gracefully */
+ crypted = xstrdup("");
}
- packet_done();
- debug("got SSH2_MSG_SERVICE_ACCEPT");
- /* setup authentication context */
- authctxt.agent = ssh_get_authentication_connection();
- authctxt.server_user = server_user;
- authctxt.host = host;
- authctxt.service = "ssh-connection"; /* service name */
- authctxt.success = 0;
- authctxt.method = authmethod_lookup("none");
- if (authctxt.method == NULL)
- fatal("ssh_userauth2: internal error: cannot send userauth none request");
- authmethod_clear();
+#ifdef JPAKE_DEBUG
+ debug3("%s: salt = %s", __func__, salt);
+ debug3("%s: scheme = %s", __func__, crypt_scheme);
+ debug3("%s: crypted = %s", __func__, crypted);
+#endif
- /* initial userauth request */
- userauth_none(&authctxt);
+ if (hash_buffer(crypted, strlen(crypted), EVP_sha256(),
+ &secret, &secret_len) != 0)
+ fatal("%s: hash_buffer", __func__);
- dispatch_init(&input_userauth_error);
- dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
- dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
- dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */
+ bzero(password, strlen(password));
+ bzero(crypted, strlen(crypted));
+ xfree(password);
+ xfree(crypted);
- if (authctxt.agent != NULL)
- ssh_close_authentication_connection(authctxt.agent);
+ if ((ret = BN_bin2bn(secret, secret_len, NULL)) == NULL)
+ fatal("%s: BN_bin2bn (secret)", __func__);
+ bzero(secret, secret_len);
+ xfree(secret);
- debug("ssh-userauth2 successfull: method %s", authctxt.method->name);
-}
-void
-input_userauth_error(int type, int plen, void *ctxt)
-{
- fatal("input_userauth_error: bad message during authentication");
+ return ret;
}
+
+/* ARGSUSED */
void
-input_userauth_success(int type, int plen, void *ctxt)
+input_userauth_jpake_server_step1(int type, u_int32_t seq, void *ctxt)
{
Authctxt *authctxt = ctxt;
- if (authctxt == NULL)
- fatal("input_userauth_success: no authentication context");
- authctxt->success = 1; /* break out */
+ struct jpake_ctx *pctx = authctxt->methoddata;
+ u_char *x3_proof, *x4_proof, *x2_s_proof;
+ u_int x3_proof_len, x4_proof_len, x2_s_proof_len;
+ char *crypt_scheme, *salt;
+
+ /* Disable this message */
+ dispatch_set(SSH2_MSG_USERAUTH_JPAKE_SERVER_STEP1, NULL);
+
+ if ((pctx->g_x3 = BN_new()) == NULL ||
+ (pctx->g_x4 = BN_new()) == NULL)
+ fatal("%s: BN_new", __func__);
+
+ /* Fetch step 1 values */
+ crypt_scheme = packet_get_string(NULL);
+ salt = packet_get_string(NULL);
+ pctx->server_id = packet_get_string(&pctx->server_id_len);
+ packet_get_bignum2(pctx->g_x3);
+ packet_get_bignum2(pctx->g_x4);
+ x3_proof = packet_get_string(&x3_proof_len);
+ x4_proof = packet_get_string(&x4_proof_len);
+ packet_check_eom();
+
+ JPAKE_DEBUG_CTX((pctx, "step 1 received in %s", __func__));
+
+ /* Obtain password and derive secret */
+ pctx->s = jpake_password_to_secret(authctxt, crypt_scheme, salt);
+ bzero(crypt_scheme, strlen(crypt_scheme));
+ bzero(salt, strlen(salt));
+ xfree(crypt_scheme);
+ xfree(salt);
+ JPAKE_DEBUG_BN((pctx->s, "%s: s = ", __func__));
+
+ /* Calculate step 2 values */
+ jpake_step2(pctx->grp, pctx->s, pctx->g_x1,
+ pctx->g_x3, pctx->g_x4, pctx->x2,
+ pctx->server_id, pctx->server_id_len,
+ pctx->client_id, pctx->client_id_len,
+ x3_proof, x3_proof_len,
+ x4_proof, x4_proof_len,
+ &pctx->a,
+ &x2_s_proof, &x2_s_proof_len);
+
+ bzero(x3_proof, x3_proof_len);
+ bzero(x4_proof, x4_proof_len);
+ xfree(x3_proof);
+ xfree(x4_proof);
+
+ JPAKE_DEBUG_CTX((pctx, "step 2 sending in %s", __func__));
+
+ /* Send values for step 2 */
+ packet_start(SSH2_MSG_USERAUTH_JPAKE_CLIENT_STEP2);
+ packet_put_bignum2(pctx->a);
+ packet_put_string(x2_s_proof, x2_s_proof_len);
+ packet_send();
+
+ bzero(x2_s_proof, x2_s_proof_len);
+ xfree(x2_s_proof);
+
+ /* Expect step 2 packet from peer */
+ dispatch_set(SSH2_MSG_USERAUTH_JPAKE_SERVER_STEP2,
+ input_userauth_jpake_server_step2);
}
+
+/* ARGSUSED */
void
-input_userauth_failure(int type, int plen, void *ctxt)
+input_userauth_jpake_server_step2(int type, u_int32_t seq, void *ctxt)
{
- Authmethod *method = NULL;
Authctxt *authctxt = ctxt;
- char *authlist = NULL;
- int partial;
+ struct jpake_ctx *pctx = authctxt->methoddata;
+ u_char *x4_s_proof;
+ u_int x4_s_proof_len;
- if (authctxt == NULL)
- fatal("input_userauth_failure: no authentication context");
+ /* Disable this message */
+ dispatch_set(SSH2_MSG_USERAUTH_JPAKE_SERVER_STEP2, NULL);
- authlist = packet_get_string(NULL);
- partial = packet_get_char();
- packet_done();
+ if ((pctx->b = BN_new()) == NULL)
+ fatal("%s: BN_new", __func__);
- if (partial != 0)
- debug("partial success");
- debug("authentications that can continue: %s", authlist);
+ /* Fetch step 2 values */
+ packet_get_bignum2(pctx->b);
+ x4_s_proof = packet_get_string(&x4_s_proof_len);
+ packet_check_eom();
- for (;;) {
- method = authmethod_get(authlist);
- if (method == NULL)
- fatal("Unable to find an authentication method");
- authctxt->method = method;
- if (method->userauth(authctxt) != 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;
- }
- }
- xfree(authlist);
-}
+ JPAKE_DEBUG_CTX((pctx, "step 2 received in %s", __func__));
-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);
+ /* Derive shared key and calculate confirmation hash */
+ jpake_key_confirm(pctx->grp, pctx->s, pctx->b,
+ pctx->x2, pctx->g_x1, pctx->g_x2, pctx->g_x3, pctx->g_x4,
+ pctx->client_id, pctx->client_id_len,
+ pctx->server_id, pctx->server_id_len,
+ session_id2, session_id2_len,
+ x4_s_proof, x4_s_proof_len,
+ &pctx->k,
+ &pctx->h_k_cid_sessid, &pctx->h_k_cid_sessid_len);
+
+ bzero(x4_s_proof, x4_s_proof_len);
+ xfree(x4_s_proof);
+
+ JPAKE_DEBUG_CTX((pctx, "confirm sending in %s", __func__));
+
+ /* Send key confirmation proof */
+ packet_start(SSH2_MSG_USERAUTH_JPAKE_CLIENT_CONFIRM);
+ packet_put_string(pctx->h_k_cid_sessid, pctx->h_k_cid_sessid_len);
packet_send();
- packet_write_wait();
- return 1;
+
+ /* Expect confirmation from peer */
+ dispatch_set(SSH2_MSG_USERAUTH_JPAKE_SERVER_CONFIRM,
+ input_userauth_jpake_server_confirm);
}
-int
-userauth_passwd(Authctxt *authctxt)
+/* ARGSUSED */
+void
+input_userauth_jpake_server_confirm(int type, u_int32_t seq, void *ctxt)
{
- static int attempt = 0;
- char prompt[80];
- char *password;
+ Authctxt *authctxt = ctxt;
+ struct jpake_ctx *pctx = authctxt->methoddata;
- if (attempt++ >= options.number_of_password_prompts)
- return 0;
+ /* Disable this message */
+ dispatch_set(SSH2_MSG_USERAUTH_JPAKE_SERVER_CONFIRM, NULL);
- if(attempt != 1)
- error("Permission denied, please try again.");
+ pctx->h_k_sid_sessid = packet_get_string(&pctx->h_k_sid_sessid_len);
+ packet_check_eom();
- snprintf(prompt, sizeof(prompt), "%.30s@%.40s'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_send();
- packet_write_wait();
- return 1;
+ JPAKE_DEBUG_CTX((pctx, "confirm received in %s", __func__));
+
+ /* Verify expected confirmation hash */
+ if (jpake_check_confirm(pctx->k,
+ pctx->server_id, pctx->server_id_len,
+ session_id2, session_id2_len,
+ pctx->h_k_sid_sessid, pctx->h_k_sid_sessid_len) == 1)
+ debug("%s: %s success", __func__, authctxt->method->name);
+ else {
+ debug("%s: confirmation mismatch", __func__);
+ /* XXX stash this so if auth succeeds then we can warn/kill */
+ }
+
+ userauth_jpake_cleanup(authctxt);
}
+#endif /* JPAKE */
-int
-sign_and_send_pubkey(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback)
+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;
- unsigned char *blob, *signature;
- int bloblen, slen;
- int skip = 0;
+ 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(k, &blob, &bloblen) == 0) {
+
+ if (key_to_blob(id->key, &blob, &bloblen) == 0) {
/* we cannot handle this key */
debug3("sign_and_send_pubkey: cannot handle key");
return 0;
buffer_init(&b);
if (datafellows & SSH_OLD_SESSIONID) {
buffer_append(&b, session_id2, session_id2_len);
- skip = session_id2_len;
+ skip = session_id2_len;
} else {
buffer_put_string(&b, session_id2, session_id2_len);
skip = buffer_len(&b);
} else {
buffer_put_cstring(&b, authctxt->method->name);
buffer_put_char(&b, have_sig);
- buffer_put_cstring(&b, key_ssh_name(k));
+ buffer_put_cstring(&b, key_ssh_name(id->key));
}
buffer_put_string(&b, blob, bloblen);
/* generate signature */
- ret = (*sign_callback)(authctxt, k, &signature, &slen, buffer_ptr(&b), buffer_len(&b));
+ ret = identity_sign(id, &signature, &slen,
+ buffer_ptr(&b), buffer_len(&b));
if (ret == -1) {
xfree(blob);
buffer_free(&b);
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(k));
+ 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);
packet_start(SSH2_MSG_USERAUTH_REQUEST);
packet_put_raw(buffer_ptr(&b), buffer_len(&b));
buffer_free(&b);
-
- /* send */
packet_send();
- packet_write_wait();
return 1;
}
-/* sign callback */
-int key_sign_cb(Authctxt *authctxt, Key *key, unsigned char **sigp, int *lenp,
- unsigned char *data, int datalen)
+static int
+send_pubkey_test(Authctxt *authctxt, Identity *id)
{
- return key_sign(key, sigp, lenp, data, datalen);
+ 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;
}
-int
-userauth_pubkey_identity(Authctxt *authctxt, char *filename)
+static Key *
+load_identity_file(char *filename)
{
- Key *k;
- int i, ret, try_next;
+ Key *private;
+ char prompt[300], *passphrase;
+ int perm_ok, quit, i;
struct stat st;
- if (stat(filename, &st) != 0) {
- debug("key does not exist: %s", filename);
- return 0;
+ if (stat(filename, &st) < 0) {
+ debug3("no such identity: %s", filename);
+ return NULL;
}
- debug("try pubkey: %s", filename);
-
- k = key_new(KEY_UNSPEC);
- if (!load_private_key(filename, "", k, NULL)) {
- int success = 0;
- char *passphrase;
- char prompt[300];
+ private = key_load_private_type(KEY_UNSPEC, filename, "", NULL, &perm_ok);
+ if (!perm_ok)
+ return NULL;
+ if (private == NULL) {
+ if (options.batch_mode)
+ return NULL;
snprintf(prompt, sizeof prompt,
- "Enter passphrase for key '%.100s': ", filename);
+ "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) {
- success = load_private_key(filename, passphrase, k, NULL);
- try_next = 0;
+ private = key_load_private_type(KEY_UNSPEC,
+ filename, passphrase, NULL, NULL);
+ quit = 0;
} else {
debug2("no passphrase given, try next key");
- try_next = 1;
+ quit = 1;
}
memset(passphrase, 0, strlen(passphrase));
xfree(passphrase);
- if (success || try_next)
+ if (private != NULL || quit)
break;
debug2("bad passphrase given, try again...");
}
- if (!success) {
- key_free(k);
- return 0;
- }
}
- ret = sign_and_send_pubkey(authctxt, k, key_sign_cb);
- key_free(k);
- return ret;
+ return private;
}
-/* sign callback */
-int agent_sign_cb(Authctxt *authctxt, Key *key, unsigned char **sigp, int *lenp,
- unsigned char *data, int datalen)
+/*
+ * try keys in the following order:
+ * 1. agent keys that are found in the config file
+ * 2. other agent keys
+ * 3. keys that are only listed in the config file
+ */
+static void
+pubkey_prepare(Authctxt *authctxt)
{
- return ssh_agent_sign(authctxt->agent, key, sigp, lenp, data, datalen);
+ Identity *id;
+ Idlist agent, files, *preferred;
+ Key *key;
+ AuthenticationConnection *ac;
+ char *comment;
+ int i, found;
+
+ TAILQ_INIT(&agent); /* keys from the agent */
+ TAILQ_INIT(&files); /* keys from the config file */
+ preferred = &authctxt->keys;
+ TAILQ_INIT(preferred); /* preferred order of keys */
+
+ /* list of keys stored in the filesystem */
+ for (i = 0; i < options.num_identity_files; i++) {
+ key = options.identity_keys[i];
+ if (key && key->type == KEY_RSA1)
+ continue;
+ options.identity_keys[i] = NULL;
+ id = xcalloc(1, 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 && !options.identities_only) {
+ id = xcalloc(1, 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);
+ }
}
-int
-userauth_pubkey_agent(Authctxt *authctxt)
+static void
+pubkey_cleanup(Authctxt *authctxt)
{
- static int called = 0;
- int ret = 0;
- char *comment;
- Key *k;
-
- if (called == 0) {
- if (ssh_get_num_identities(authctxt->agent, 2) == 0)
- debug2("userauth_pubkey_agent: no keys at all");
- called = 1;
- }
- k = ssh_get_next_identity(authctxt->agent, &comment, 2);
- if (k == NULL) {
- debug2("userauth_pubkey_agent: no more keys");
- } else {
- debug("userauth_pubkey_agent: trying agent key %s", comment);
- xfree(comment);
- ret = sign_and_send_pubkey(authctxt, k, agent_sign_cb);
- key_free(k);
+ Identity *id;
+
+ if (authctxt->agent != NULL)
+ ssh_close_authentication_connection(authctxt->agent);
+ for (id = TAILQ_FIRST(&authctxt->keys); id;
+ id = TAILQ_FIRST(&authctxt->keys)) {
+ TAILQ_REMOVE(&authctxt->keys, id, next);
+ if (id->key)
+ key_free(id->key);
+ if (id->filename)
+ xfree(id->filename);
+ xfree(id);
}
- if (ret == 0)
- debug2("userauth_pubkey_agent: no message sent");
- return ret;
}
int
userauth_pubkey(Authctxt *authctxt)
{
- static int idx = 0;
+ Identity *id;
int sent = 0;
- if (authctxt->agent != NULL) {
- do {
- sent = userauth_pubkey_agent(authctxt);
- } while(!sent && authctxt->agent->howmany > 0);
- }
- while (!sent && idx < options.num_identity_files) {
- if (options.identity_files_type[idx] != KEY_RSA1)
- sent = userauth_pubkey_identity(authctxt,
- options.identity_files[idx]);
- idx++;
+ 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 && 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 sent;
+ return (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(options.kbd_interactive_devices ?
options.kbd_interactive_devices : "");
packet_send();
- packet_write_wait();
dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
return 1;
}
/*
- * parse SSH2_MSG_USERAUTH_INFO_REQUEST, prompt user and send
- * SSH2_MSG_USERAUTH_INFO_RESPONSE
+ * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
*/
void
-input_userauth_info_req(int type, int plen, void *ctxt)
+input_userauth_info_req(int type, u_int32_t seq, void *ctxt)
{
Authctxt *authctxt = ctxt;
- char *name = NULL;
- char *inst = NULL;
- char *lang = NULL;
- char *prompt = NULL;
- char *response = NULL;
- unsigned int num_prompts, i;
+ 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)
- cli_mesg(name);
- xfree(name);
-
+ logit("%s", name);
if (strlen(inst) > 0)
- cli_mesg(inst);
+ logit("%s", inst);
+ xfree(name);
xfree(inst);
- xfree(lang); /* unused */
+ xfree(lang);
num_prompts = packet_get_int();
/*
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 = cli_prompt(prompt, echo);
+ response = read_passphrase(prompt, echo ? RP_ECHO : 0);
packet_put_cstring(response);
memset(response, 0, strlen(response));
xfree(response);
xfree(prompt);
}
- packet_done(); /* done with parsing incoming message. */
+ packet_check_eom(); /* done with parsing incoming message. */
+ packet_add_padding(64);
packet_send();
- packet_write_wait();
}
-/* find auth method */
+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");
-#define DELIM ","
+ 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) {
+ /* keep the socket on exec */
+ fcntl(packet_get_connection_in(), F_SETFD, 0);
+ permanently_drop_suid(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]);
-static char *def_authlist = "publickey,password";
-static char *authlist_current = NULL; /* clean copy used for comparison */
-static char *authname_current = NULL; /* last used auth method */
-static char *authlist_working = NULL; /* copy that gets modified by strtok_r() */
-static char *authlist_state = NULL; /* state variable for strtok_r() */
+ buffer_init(&b);
+ buffer_put_int(&b, packet_get_connection_in()); /* send # of socket */
+ buffer_put_string(&b, data, datalen);
+ if (ssh_msg_send(to[1], version, &b) == -1)
+ fatal("ssh_keysign: couldn't send request");
-/*
- * Before starting to use a new authentication method list sent by the
- * server, reset internal variables. This should also be called when
- * finished processing server list to free resources.
- */
-void
-authmethod_clear()
+ if (ssh_msg_recv(from[0], &b) < 0) {
+ error("ssh_keysign: no reply");
+ buffer_free(&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_free(&b);
+ return -1;
+ }
+ *sigp = buffer_get_string(&b, lenp);
+ buffer_free(&b);
+
+ return 0;
+}
+
+int
+userauth_hostbased(Authctxt *authctxt)
{
- if (authlist_current != NULL) {
- xfree(authlist_current);
- authlist_current = NULL;
+ Key *private = NULL;
+ Sensitive *sensitive = authctxt->sensitive;
+ Buffer b;
+ u_char *signature, *blob;
+ char *chost, *pkalg, *p, myname[NI_MAXHOST];
+ const char *service;
+ u_int blen, slen;
+ int ok, i, found = 0;
+
+ /* check for a useful key */
+ for (i = 0; i < sensitive->nkeys; i++) {
+ private = sensitive->keys[i];
+ if (private && private->type != KEY_RSA1) {
+ found = 1;
+ /* 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 = NULL;
+ if (packet_connection_is_on_socket())
+ p = get_local_name(packet_get_connection_in());
+ if (p == NULL) {
+ if (gethostname(myname, sizeof(myname)) == -1) {
+ verbose("userauth_hostbased: gethostname: %s",
+ strerror(errno));
+ } else
+ p = xstrdup(myname);
+ }
+ if (p == NULL) {
+ error("userauth_hostbased: cannot get local ipaddr/name");
+ key_free(private);
+ xfree(blob);
+ return 0;
}
- if (authlist_working != NULL) {
- xfree(authlist_working);
- authlist_working = NULL;
+ xasprintf(&chost, "%s.", p);
+ 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);
+ xfree(blob);
+ return 0;
}
- if (authname_current != NULL) {
- xfree(authname_current);
- authlist_state = NULL;
+ 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);
+ xfree(blob);
+
+ packet_send();
+ return 1;
+}
+
+#ifdef JPAKE
+int
+userauth_jpake(Authctxt *authctxt)
+{
+ struct jpake_ctx *pctx;
+ u_char *x1_proof, *x2_proof;
+ u_int x1_proof_len, x2_proof_len;
+ static int attempt = 0; /* XXX share with userauth_password's? */
+
+ if (attempt++ >= options.number_of_password_prompts)
+ return 0;
+ if (attempt != 1)
+ error("Permission denied, please try again.");
+
+ if (authctxt->methoddata != NULL)
+ fatal("%s: authctxt->methoddata already set (%p)",
+ __func__, authctxt->methoddata);
+
+ authctxt->methoddata = pctx = jpake_new();
+
+ /*
+ * Send request immediately, to get the protocol going while
+ * we do the initial computations.
+ */
+ 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();
+ packet_write_wait();
+
+ jpake_step1(pctx->grp,
+ &pctx->client_id, &pctx->client_id_len,
+ &pctx->x1, &pctx->x2, &pctx->g_x1, &pctx->g_x2,
+ &x1_proof, &x1_proof_len,
+ &x2_proof, &x2_proof_len);
+
+ JPAKE_DEBUG_CTX((pctx, "step 1 sending in %s", __func__));
+
+ packet_start(SSH2_MSG_USERAUTH_JPAKE_CLIENT_STEP1);
+ packet_put_string(pctx->client_id, pctx->client_id_len);
+ packet_put_bignum2(pctx->g_x1);
+ packet_put_bignum2(pctx->g_x2);
+ packet_put_string(x1_proof, x1_proof_len);
+ packet_put_string(x2_proof, x2_proof_len);
+ packet_send();
+
+ bzero(x1_proof, x1_proof_len);
+ bzero(x2_proof, x2_proof_len);
+ xfree(x1_proof);
+ xfree(x2_proof);
+
+ /* Expect step 1 packet from peer */
+ dispatch_set(SSH2_MSG_USERAUTH_JPAKE_SERVER_STEP1,
+ input_userauth_jpake_server_step1);
+ dispatch_set(SSH2_MSG_USERAUTH_SUCCESS,
+ &input_userauth_success_unexpected);
+
+ return 1;
+}
+
+void
+userauth_jpake_cleanup(Authctxt *authctxt)
+{
+ debug3("%s: clean up", __func__);
+ if (authctxt->methoddata != NULL) {
+ jpake_free(authctxt->methoddata);
+ authctxt->methoddata = NULL;
}
- if (authlist_state != NULL)
- authlist_state = NULL;
- return;
+ dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
}
+#endif /* JPAKE */
+
+/* find auth method */
/*
* given auth method name, if configurable options permit this method fill
* in auth_ident field and return true, otherwise return false.
*/
-int
+static int
authmethod_is_enabled(Authmethod *method)
{
if (method == NULL)
return 1;
}
-Authmethod *
+static Authmethod *
authmethod_lookup(const char *name)
{
Authmethod *method = 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. If the server sends a nil list after
- * previously sending a valid list, continue using the list originally
- * sent.
- */
-
-Authmethod *
+ * use a built-in default list.
+ */
+static Authmethod *
authmethod_get(char *authlist)
{
- char *name = NULL, *authname_old;
- Authmethod *method = NULL;
-
+ char *name = NULL;
+ u_int next;
+
/* Use a suitable default if we're passed a nil list. */
if (authlist == NULL || strlen(authlist) == 0)
- authlist = def_authlist;
-
- if (authlist_current == NULL || strcmp(authlist, authlist_current) != 0) {
- /* start over if passed a different list */
- debug3("start over, passed a different list");
- authmethod_clear();
- authlist_current = xstrdup(authlist);
- authlist_working = xstrdup(authlist);
- name = strtok_r(authlist_working, DELIM, &authlist_state);
- } else {
- /*
- * try to use previously used authentication method
- * or continue to use previously passed list
- */
- name = (authname_current != NULL) ?
- authname_current : strtok_r(NULL, DELIM, &authlist_state);
- }
+ 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;
- while (name != NULL) {
+ 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);
- method = authmethod_lookup(name);
- if (method != NULL && authmethod_is_enabled(method)) {
+ debug3("remaining preferred: %s", preferred);
+ if ((current = authmethod_lookup(name)) != NULL &&
+ authmethod_is_enabled(current)) {
debug3("authmethod_is_enabled %s", name);
- break;
+ debug("Next authentication method: %s", name);
+ return current;
}
- name = strtok_r(NULL, DELIM, &authlist_state);
- method = NULL;
- }
-
- authname_old = authname_current;
- if (method != NULL) {
- debug("next auth method to try is %s", name);
- authname_current = xstrdup(name);
- } else {
- debug("no more auth methods to try");
- authname_current = NULL;
}
+}
- if (authname_old != NULL)
- xfree(authname_old);
+static char *
+authmethods_get(void)
+{
+ Authmethod *method = NULL;
+ Buffer b;
+ char *list;
- return (method);
+ 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;
}
+
andersk / openssh.git / blobdiff