X-Git-Url: http://andersk.mit.edu/gitweb/gssapi-openssh.git/blobdiff_plain/5ff39d34a50802bab296b50eb09d097062e07f03..22ce3a3becb01f9487f7fa12b859100c162e231c:/openssh/sshconnect2.c diff --git a/openssh/sshconnect2.c b/openssh/sshconnect2.c index cc6563f..c4136d5 100644 --- a/openssh/sshconnect2.c +++ b/openssh/sshconnect2.c @@ -1,5 +1,7 @@ +/* $OpenBSD: sshconnect2.c,v 1.171 2009/03/05 07:18:19 djm Exp $ */ /* * Copyright (c) 2000 Markus Friedl. All rights reserved. + * Copyright (c) 2008 Damien Miller. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions @@ -23,16 +25,34 @@ */ #include "includes.h" -RCSID("$OpenBSD: sshconnect2.c,v 1.114 2003/04/01 10:22:21 markus Exp $"); +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#if defined(HAVE_STRNVIS) && defined(HAVE_VIS_H) +#include +#endif + +#include "openbsd-compat/sys-queue.h" + +#include "xmalloc.h" #include "ssh.h" #include "ssh2.h" -#include "xmalloc.h" #include "buffer.h" #include "packet.h" #include "compat.h" -#include "bufaux.h" #include "cipher.h" +#include "key.h" #include "kex.h" #include "myproposal.h" #include "sshconnect.h" @@ -41,12 +61,15 @@ RCSID("$OpenBSD: sshconnect2.c,v 1.114 2003/04/01 10:22:21 markus Exp $"); #include "authfd.h" #include "log.h" #include "readconf.h" -#include "readpass.h" +#include "misc.h" #include "match.h" #include "dispatch.h" #include "canohost.h" #include "msg.h" #include "pathnames.h" +#include "uidswap.h" +#include "schnorr.h" +#include "jpake.h" #ifdef GSSAPI #include "ssh-gss.h" @@ -56,13 +79,29 @@ RCSID("$OpenBSD: sshconnect2.c,v 1.114 2003/04/01 10:22:21 markus Exp $"); extern char *client_version_string; extern char *server_version_string; extern Options options; +extern Kex *xxx_kex; + +/* tty_flag is set in ssh.c. use this in ssh_userauth2 */ +/* if it is set then prevent the switch to the null cipher */ + +extern int tty_flag; + +/* tty_flag is set in ssh.c. use this in ssh_userauth2 */ +/* if it is set then prevent the switch to the null cipher */ + +extern int tty_flag; + +/* tty_flag is set in ssh.c. use this in ssh_userauth2 */ +/* if it is set then prevent the switch to the null cipher */ + +extern int tty_flag; /* * SSH2 key exchange */ u_char *session_id2 = NULL; -int session_id2_len = 0; +u_int session_id2_len = 0; char *xxx_host; struct sockaddr *xxx_hostaddr; @@ -81,9 +120,10 @@ void ssh_kex2(char *host, struct sockaddr *hostaddr) { Kex *kex; + #ifdef GSSAPI - char *orig, *gss; - int len; + char *orig = NULL, *gss = NULL; + char *gss_host = NULL; #endif xxx_host = host; @@ -91,25 +131,26 @@ ssh_kex2(char *host, struct sockaddr *hostaddr) #ifdef GSSAPI if (options.gss_keyex) { - char *canonhost; - /* Add the GSSAPI mechanisms currently supported on this client to - * the key exchange algorithm proposal */ - orig = myproposal[PROPOSAL_KEX_ALGS]; - canonhost = xstrdup(get_canonical_hostname(1)); - resolve_localhost(&canonhost); - gss = ssh_gssapi_client_mechanisms(canonhost); - xfree(canonhost); - canonhost=NULL; - if (gss) { - len = strlen(orig)+strlen(gss)+2; - myproposal[PROPOSAL_KEX_ALGS]=xmalloc(len); - snprintf(myproposal[PROPOSAL_KEX_ALGS],len,"%s,%s",gss,orig); - } + /* Add the GSSAPI mechanisms currently supported on this + * client to the key exchange algorithm proposal */ + orig = myproposal[PROPOSAL_KEX_ALGS]; + + if (options.gss_trust_dns) + gss_host = (char *)get_canonical_hostname(1); + else + gss_host = host; + + gss = ssh_gssapi_client_mechanisms(gss_host, options.gss_client_identity); + if (gss) { + debug("Offering GSSAPI proposal: %s", gss); + xasprintf(&myproposal[PROPOSAL_KEX_ALGS], + "%s,%s", gss, orig); + } } #endif 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) { @@ -122,10 +163,10 @@ ssh_kex2(char *host, struct sockaddr *hostaddr) compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]); if (options.compression) { myproposal[PROPOSAL_COMP_ALGS_CTOS] = - myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib,none"; + myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib@openssh.com,zlib,none"; } else { myproposal[PROPOSAL_COMP_ALGS_CTOS] = - myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib"; + myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib@openssh.com,zlib"; } if (options.macs != NULL) { myproposal[PROPOSAL_MAC_ALGS_CTOS] = @@ -136,28 +177,45 @@ ssh_kex2(char *host, struct sockaddr *hostaddr) options.hostkeyalgorithms; #ifdef GSSAPI - /* If we've got GSSAPI algorithms, then we also support the - * 'null' hostkey, as a last resort */ + /* If we've got GSSAPI algorithms, then we also support the + * 'null' hostkey, as a last resort */ if (options.gss_keyex && gss) { - orig=myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS]; - len = strlen(orig)+sizeof(",null"); - myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS]=xmalloc(len); - snprintf(myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS],len,"%s,null",orig); + orig = myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS]; + xasprintf(&myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS], + "%s,null", orig); + xfree(gss); } #endif + + 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; #ifdef GSSAPI - kex->kex[KEX_GSS_GRP1_SHA1] = kexgss_client; + if (options.gss_keyex) { + kex->kex[KEX_GSS_GRP1_SHA1] = kexgss_client; + kex->kex[KEX_GSS_GRP14_SHA1] = kexgss_client; + kex->kex[KEX_GSS_GEX_SHA1] = kexgss_client; + } #endif kex->client_version_string=client_version_string; kex->server_version_string=server_version_string; kex->verify_host_key=&verify_host_key_callback; + #ifdef GSSAPI - kex->options.gss_deleg_creds=options.gss_deleg_creds; + if (options.gss_keyex) { + kex->gss_deleg_creds = options.gss_deleg_creds; + kex->gss_trust_dns = options.gss_trust_dns; + kex->gss_client = options.gss_client_identity; + kex->gss_host = gss_host; + } #endif + xxx_kex = kex; dispatch_run(DISPATCH_BLOCK, &kex->done, kex); @@ -180,10 +238,18 @@ ssh_kex2(char *host, struct sockaddr *hostaddr) typedef struct Authctxt Authctxt; typedef struct Authmethod Authmethod; - -typedef int sign_cb_fn( - Authctxt *authctxt, Key *key, - u_char **sigp, u_int *lenp, u_char *data, u_int datalen); +typedef struct identity Identity; +typedef struct idlist Idlist; + +struct identity { + TAILQ_ENTRY(identity) next; + AuthenticationConnection *ac; /* set if agent supports key */ + Key *key; /* public/private key */ + char *filename; /* comment for agent-only keys */ + int tried; + int isprivate; /* key points to the private key */ +}; +TAILQ_HEAD(idlist, identity); struct Authctxt { const char *server_user; @@ -194,9 +260,7 @@ struct Authctxt { int success; char *authlist; /* pubkey */ - Key *last_key; - sign_cb_fn *last_key_sign; - int last_key_hint; + Idlist keys; AuthenticationConnection *agent; /* hostbased */ Sensitive *sensitive; @@ -208,6 +272,7 @@ struct Authctxt { 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 */ }; @@ -219,27 +284,35 @@ 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_external(Authctxt *authctxt); int userauth_gssapi(Authctxt *authctxt); void input_gssapi_response(int type, u_int32_t, void *); void input_gssapi_token(int type, u_int32_t, void *); void input_gssapi_hash(int type, u_int32_t, void *); void input_gssapi_error(int, u_int32_t, void *); void input_gssapi_errtok(int, u_int32_t, void *); +int userauth_gsskeyex(Authctxt *authctxt); #endif void userauth(Authctxt *, char *); -static int sign_and_send_pubkey(Authctxt *, Key *, sign_cb_fn *); -static void clear_auth_state(Authctxt *); +static int sign_and_send_pubkey(Authctxt *, Identity *); +static void pubkey_prepare(Authctxt *); +static void pubkey_cleanup(Authctxt *); +static Key *load_identity_file(char *); static Authmethod *authmethod_get(char *authlist); static Authmethod *authmethod_lookup(const char *name); @@ -247,36 +320,50 @@ static char *authmethods_get(void); Authmethod authmethods[] = { #ifdef GSSAPI - {"external-keyx", - userauth_external, + {"gssapi-keyex", + userauth_gsskeyex, + NULL, &options.gss_authentication, NULL}, - {"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, NULL, NULL, NULL, NULL} }; void @@ -312,7 +399,7 @@ ssh_userauth2(const char *local_user, const char *server_user, char *host, /* setup authentication context */ memset(&authctxt, 0, sizeof(authctxt)); - authctxt.agent = ssh_get_authentication_connection(); + pubkey_prepare(&authctxt); authctxt.server_user = server_user; authctxt.local_user = local_user; authctxt.host = host; @@ -335,19 +422,44 @@ ssh_userauth2(const char *local_user, const char *server_user, char *host, dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner); dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */ - if (authctxt.agent != NULL) - ssh_close_authentication_connection(authctxt.agent); - + pubkey_cleanup(&authctxt); + dispatch_range(SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL); + + /* if the user wants to use the none cipher do it */ + /* post authentication and only if the right conditions are met */ + /* both of the NONE commands must be true and there must be no */ + /* tty allocated */ + if ((options.none_switch == 1) && (options.none_enabled == 1)) + { + if (!tty_flag) /* no null on tty sessions */ + { + debug("Requesting none rekeying..."); + myproposal[PROPOSAL_ENC_ALGS_STOC] = "none"; + myproposal[PROPOSAL_ENC_ALGS_CTOS] = "none"; + kex_prop2buf(&xxx_kex->my,myproposal); + packet_request_rekeying(); + fprintf(stderr, "WARNING: ENABLED NONE CIPHER\n"); + } + else + { + /* requested NONE cipher when in a tty */ + debug("Cannot switch to NONE cipher with tty allocated"); + fprintf(stderr, "NONE cipher switch disabled when a TTY is allocated\n"); + } + } debug("Authentication succeeded (%s).", authctxt.method->name); } + void userauth(Authctxt *authctxt, char *authlist) { - if (authctxt->methoddata!=NULL) { + if (authctxt->method != NULL && authctxt->method->cleanup != NULL) + authctxt->method->cleanup(authctxt); + + if (authctxt->methoddata) { xfree(authctxt->methoddata); - authctxt->methoddata=NULL; + authctxt->methoddata = NULL; } - if (authlist == NULL) { authlist = authctxt->authlist; } else { @@ -360,6 +472,12 @@ userauth(Authctxt *authctxt, char *authlist) if (method == NULL) fatal("Permission denied (%s).", authlist); authctxt->method = method; + + /* reset the per method handler */ + dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN, + SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL); + + /* and try new method */ if (method->userauth(authctxt) != 0) { debug2("we sent a %s packet, wait for reply", method->name); break; @@ -370,39 +488,55 @@ userauth(Authctxt *authctxt, char *authlist) } } +/* ARGSUSED */ void input_userauth_error(int type, u_int32_t seq, void *ctxt) { fatal("input_userauth_error: bad message during authentication: " - "type %d", type); + "type %d", type); } +/* ARGSUSED */ void input_userauth_banner(int type, u_int32_t seq, void *ctxt) { - char *msg, *lang; + char *msg, *raw, *lang; + u_int len; + debug3("input_userauth_banner"); - msg = packet_get_string(NULL); + raw = packet_get_string(&len); lang = packet_get_string(NULL); - fprintf(stderr, "%s", msg); - xfree(msg); + 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); + fprintf(stderr, "%s", msg); + xfree(msg); + } + xfree(raw); xfree(lang); } +/* ARGSUSED */ void input_userauth_success(int type, u_int32_t seq, void *ctxt) { Authctxt *authctxt = ctxt; if (authctxt == NULL) fatal("input_userauth_success: no authentication context"); - if (authctxt->authlist) + if (authctxt->authlist) { xfree(authctxt->authlist); - if (authctxt->methoddata) + authctxt->authlist = NULL; + } + if (authctxt->methoddata) { xfree(authctxt->methoddata); - clear_auth_state(authctxt); + authctxt->methoddata = NULL; + } authctxt->success = 1; /* break out */ } +/* ARGSUSED */ void input_userauth_failure(int type, u_int32_t seq, void *ctxt) { @@ -418,17 +552,19 @@ input_userauth_failure(int type, u_int32_t seq, void *ctxt) packet_check_eom(); if (partial != 0) - log("Authenticated with partial success."); + logit("Authenticated with partial success."); debug("Authentications that can continue: %s", authlist); - clear_auth_state(authctxt); userauth(authctxt, authlist); } + +/* 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; @@ -451,318 +587,360 @@ input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt) } packet_check_eom(); - debug("Server accepts key: pkalg %s blen %u lastkey %p hint %d", - pkalg, blen, authctxt->last_key, authctxt->last_key_hint); + debug("Server accepts key: pkalg %s blen %u", pkalg, blen); - do { - if (authctxt->last_key == NULL || - authctxt->last_key_sign == NULL) { - debug("no last key or no sign cb"); - break; - } - if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) { - debug("unknown pkalg %s", pkalg); - break; - } - if ((key = key_from_blob(pkblob, blen)) == NULL) { - debug("no key from blob. pkalg %s", pkalg); - break; - } - if (key->type != pktype) { - error("input_userauth_pk_ok: type mismatch " - "for decoded key (received %d, expected %d)", - key->type, pktype); - break; - } - fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX); - debug2("input_userauth_pk_ok: fp %s", fp); - xfree(fp); - if (!key_equal(key, authctxt->last_key)) { - debug("key != last_key"); + if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) { + debug("unknown pkalg %s", pkalg); + goto done; + } + if ((key = key_from_blob(pkblob, blen)) == NULL) { + debug("no key from blob. pkalg %s", pkalg); + goto done; + } + if (key->type != pktype) { + error("input_userauth_pk_ok: type mismatch " + "for decoded key (received %d, expected %d)", + key->type, pktype); + goto done; + } + fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX); + debug2("input_userauth_pk_ok: fp %s", fp); + xfree(fp); + + /* + * 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; } - sent = sign_and_send_pubkey(authctxt, key, - authctxt->last_key_sign); - } while (0); - + } +done: if (key != NULL) key_free(key); xfree(pkalg); xfree(pkblob); - /* unregister */ - clear_auth_state(authctxt); - dispatch_set(SSH2_MSG_USERAUTH_PK_OK, NULL); - /* try another method if we did not send a packet */ if (sent == 0) userauth(authctxt, NULL); - } #ifdef GSSAPI -int +int userauth_gssapi(Authctxt *authctxt) { Gssctxt *gssctxt = NULL; - static gss_OID_set supported = NULL; - static int mech=0; + static gss_OID_set gss_supported = NULL; + static u_int mech = 0; OM_uint32 min; - int ok=0; - - /* Things work better if we send one mechanism at a time, rather - * than them all at once. This means that if we fail at some point - * in the middle of a negotiation, we can come back and try something - * different. */ - - if (datafellows & SSH_OLD_GSSAPI) return 0; - - /* Before we offer a mechanism, check that we can support it. Don't - * bother trying to get credentials - as the standard fallback will - * deal with that kind of failure. - */ + int ok = 0; + char *gss_host = NULL; - if (supported==NULL) gss_indicate_mechs(&min, &supported); - - while (mechcount && !ok) { - if (gssctxt) ssh_gssapi_delete_ctx(&gssctxt); - ssh_gssapi_build_ctx(&gssctxt); - ssh_gssapi_set_oid(gssctxt,&supported->elements[mech]); + if (!options.gss_authentication) { + verbose("GSSAPI authentication disabled."); + return 0; + } - /* The DER encoding below only works for lengths<128, - * so check this here - */ - if (supported->elements[mech].length<128 && - !GSS_ERROR(ssh_gssapi_import_name(gssctxt, - authctxt->host))) { - ok = 1; /* Mechanism works */ + if (options.gss_trust_dns) + gss_host = (char *)get_canonical_hostname(1); + else + gss_host = (char *)authctxt->host; + + /* Try one GSSAPI method at a time, rather than sending them all at + * once. */ + + if (gss_supported == NULL) + if (GSS_ERROR(gss_indicate_mechs(&min, &gss_supported))) { + gss_supported = NULL; + return 0; + } + + /* 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], gss_host, + options.gss_client_identity)) { + ok = 1; /* Mechanism works */ } else { mech++; } } - - if (!ok) return 0; - + + 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_cstring(authctxt->method->name); + packet_put_int(1); - /* The newest gsskeyex draft stipulates that OIDs should - * be DER encoded, so we need to add the object type and - * length information back on */ - 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(0x06); - packet_put_char(supported->elements[mech].length); - packet_put_raw(supported->elements[mech].elements, - supported->elements[mech].length); - } + 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); - packet_send(); - packet_write_wait(); + 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); - 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; + return 1; } +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; + + status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds, + recv_tok, &send_tok, &flags); + + if (send_tok.length > 0) { + if (GSS_ERROR(status)) + packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK); + else + 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) { + /* send either complete or MIC, depending on mechanism */ + if (strcmp(authctxt->method->name,"gssapi")==0 || + (!(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"); + + gssbuf.value = buffer_ptr(&b); + gssbuf.length = buffer_len(&b); + + 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); + + packet_send(); + } + + buffer_free(&b); + gss_release_buffer(&ms, &mic); + } + } + + return status; +} + +/* ARGSUSED */ void -input_gssapi_response(int type, u_int32_t plen, void *ctxt) +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; - + u_int oidlen; + u_char *oidv; + 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"); - } - ssh_gssapi_set_oid_data(gssctxt,oidv,oidlen); - } else { - if(oidv[0]!=0x06 || oidv[1]!=oidlen-2) { - debug("Badly encoded mechanism OID received"); - clear_auth_state(authctxt); - userauth(authctxt,NULL); - return; - } - if (!ssh_gssapi_check_oid(gssctxt,oidv+2,oidlen-2)) { - fatal("Server returned different OID than expected"); - } - ssh_gssapi_set_oid_data(gssctxt,oidv+2,oidlen-2); + 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; } - + + if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2)) + fatal("Server returned different OID than expected"); + packet_check_eom(); - - 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(); - packet_write_wait(); - } + + xfree(oidv); + + if (GSS_ERROR(process_gssapi_token(ctxt, GSS_C_NO_BUFFER))) { /* Start again with next method on list */ debug("Trying to start again"); - clear_auth_state(authctxt); - userauth(authctxt,NULL); + 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(); - packet_write_wait(); - gss_release_buffer(&ms, &send_tok); } +/* ARGSUSED */ void input_gssapi_token(int type, u_int32_t plen, void *ctxt) { Authctxt *authctxt = ctxt; - Gssctxt *gssctxt; - gss_buffer_desc send_tok,recv_tok; + gss_buffer_desc recv_tok; OM_uint32 status; u_int slen; - + if (authctxt == NULL) - fatal("input_gssapi_token: no authentication context"); - gssctxt = authctxt->methoddata; - - recv_tok.value=packet_get_string(&slen); - recv_tok.length=slen; /* safe typecast */ + fatal("input_gssapi_response: no authentication context"); - status=ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds, - &recv_tok, &send_tok, NULL); + 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)) { - if (send_tok.length>0) { - packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK); - packet_put_string(send_tok.value,send_tok.length); - packet_send(); - packet_write_wait(); - } /* Start again with the next method in the list */ - clear_auth_state(authctxt); - userauth(authctxt,NULL); + 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(); - packet_write_wait(); - } - - if (status == GSS_S_COMPLETE) { - /* If that succeeded, send a exchange complete message */ - packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE); - packet_send(); - packet_write_wait(); - } } +/* ARGSUSED */ void input_gssapi_errtok(int type, u_int32_t plen, void *ctxt) { Authctxt *authctxt = ctxt; Gssctxt *gssctxt; - gss_buffer_desc send_tok,recv_tok; - OM_uint32 status; - + 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(&recv_tok.length); - /* Stick it into GSSAPI and see what it says */ - status=ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds, - &recv_tok, &send_tok, NULL); + recv_tok.value = packet_get_string(&len); + recv_tok.length = len; packet_check_eom(); - - /* We can't send a packet to the server */ - - /* The draft says that we should wait for the server to fail - * before starting the next authentication. So, we clear the - * state, but don't do anything else */ - clear_auth_state(authctxt); - return; + + /* 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; + 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(); - - fprintf(stderr, "Server GSSAPI Error:\n%s\n", msg); + + debug("Server GSSAPI Error:\n%s", msg); xfree(msg); xfree(lang); } +#ifdef GSI +extern +const gss_OID_desc * const gss_mech_globus_gssapi_openssl; +#define is_gsi_oid(oid) \ + (oid->length == gss_mech_globus_gssapi_openssl->length && \ + (memcmp(oid->elements, gss_mech_globus_gssapi_openssl->elements, \ + oid->length) == 0)) +#endif + int -userauth_external(Authctxt *authctxt) +userauth_gsskeyex(Authctxt *authctxt) { - static int attempt =0; - - if (attempt++ >= 1) - return 0; - - debug2("userauth_external"); - packet_start(SSH2_MSG_USERAUTH_REQUEST); + Buffer b; + gss_buffer_desc gssbuf; + gss_buffer_desc mic = GSS_C_EMPTY_BUFFER; + OM_uint32 ms; + + static int attempt = 0; + if (attempt++ >= 1) + return (0); + + if (gss_kex_context == NULL) { + debug("No valid Key exchange context"); + return (0); + } + +#ifdef GSI + if (options.implicit && is_gsi_oid(gss_kex_context->oid)) { + ssh_gssapi_buildmic(&b, "", authctxt->service, "gssapi-keyex"); + } else { +#endif + ssh_gssapi_buildmic(&b, authctxt->server_user, authctxt->service, + "gssapi-keyex"); +#ifdef GSI + } +#endif + + gssbuf.value = buffer_ptr(&b); + gssbuf.length = buffer_len(&b); + + if (GSS_ERROR(ssh_gssapi_sign(gss_kex_context, &gssbuf, &mic))) { + buffer_free(&b); + return (0); + } + + packet_start(SSH2_MSG_USERAUTH_REQUEST); #ifdef GSI - if(options.implicit && !(datafellows & SSH_BUG_GSS_EMPTYUSER)) { - packet_put_cstring(""); + if (options.implicit && is_gsi_oid(gss_kex_context->oid)) { + packet_put_cstring(""); } else { #endif - packet_put_cstring(authctxt->server_user); + packet_put_cstring(authctxt->server_user); #ifdef GSI } #endif - packet_put_cstring(authctxt->service); - packet_put_cstring(authctxt->method->name); - packet_send(); - packet_write_wait(); - return 1; -} + packet_put_cstring(authctxt->service); + packet_put_cstring(authctxt->method->name); + packet_put_string(mic.value, mic.length); + packet_send(); + + buffer_free(&b); + gss_release_buffer(&ms, &mic); + + return (1); +} + #endif /* GSSAPI */ int @@ -775,7 +953,6 @@ userauth_none(Authctxt *authctxt) packet_put_cstring(authctxt->method->name); packet_send(); return 1; - } int @@ -810,9 +987,11 @@ userauth_passwd(Authctxt *authctxt) 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) { @@ -829,7 +1008,7 @@ input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt) info = packet_get_string(NULL); lang = packet_get_string(NULL); if (strlen(info) > 0) - log("%s", info); + logit("%s", info); xfree(info); xfree(lang); packet_start(SSH2_MSG_USERAUTH_REQUEST); @@ -861,7 +1040,7 @@ input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt) if (strcmp(password, retype) != 0) { memset(password, 0, strlen(password)); xfree(password); - log("Mismatch; try again, EOF to quit."); + logit("Mismatch; try again, EOF to quit."); password = NULL; } memset(retype, 0, strlen(retype)); @@ -877,39 +1056,247 @@ input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt) &input_userauth_passwd_changereq); } -static void -clear_auth_state(Authctxt *authctxt) +#ifdef JPAKE +static char * +pw_encrypt(const char *password, const char *crypt_scheme, const char *salt) { - /* XXX clear authentication state */ - dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, NULL); -#ifdef GSSAPI - dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE,NULL); - dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN,NULL); - dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR,NULL); + /* 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(""); + } + +#ifdef JPAKE_DEBUG + debug3("%s: salt = %s", __func__, salt); + debug3("%s: scheme = %s", __func__, crypt_scheme); + debug3("%s: crypted = %s", __func__, crypted); #endif - - if (authctxt->last_key != NULL && authctxt->last_key_hint == -1) { - debug3("clear_auth_state: key_free %p", authctxt->last_key); - key_free(authctxt->last_key); - } - authctxt->last_key = NULL; - authctxt->last_key_hint = -2; - authctxt->last_key_sign = NULL; + + if (hash_buffer(crypted, strlen(crypted), EVP_sha256(), + &secret, &secret_len) != 0) + fatal("%s: hash_buffer", __func__); + + bzero(password, strlen(password)); + bzero(crypted, strlen(crypted)); + xfree(password); + xfree(crypted); + + if ((ret = BN_bin2bn(secret, secret_len, NULL)) == NULL) + fatal("%s: BN_bin2bn (secret)", __func__); + bzero(secret, secret_len); + xfree(secret); + + return ret; +} + +/* ARGSUSED */ +void +input_userauth_jpake_server_step1(int type, u_int32_t seq, void *ctxt) +{ + Authctxt *authctxt = ctxt; + 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_jpake_server_step2(int type, u_int32_t seq, void *ctxt) +{ + Authctxt *authctxt = ctxt; + struct jpake_ctx *pctx = authctxt->methoddata; + u_char *x4_s_proof; + u_int x4_s_proof_len; + + /* Disable this message */ + dispatch_set(SSH2_MSG_USERAUTH_JPAKE_SERVER_STEP2, NULL); + + if ((pctx->b = BN_new()) == NULL) + fatal("%s: BN_new", __func__); + + /* Fetch step 2 values */ + packet_get_bignum2(pctx->b); + x4_s_proof = packet_get_string(&x4_s_proof_len); + packet_check_eom(); + + JPAKE_DEBUG_CTX((pctx, "step 2 received in %s", __func__)); + + /* 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(); + + /* Expect confirmation from peer */ + dispatch_set(SSH2_MSG_USERAUTH_JPAKE_SERVER_CONFIRM, + input_userauth_jpake_server_confirm); +} + +/* ARGSUSED */ +void +input_userauth_jpake_server_confirm(int type, u_int32_t seq, void *ctxt) +{ + Authctxt *authctxt = ctxt; + struct jpake_ctx *pctx = authctxt->methoddata; + + /* Disable this message */ + dispatch_set(SSH2_MSG_USERAUTH_JPAKE_SERVER_CONFIRM, NULL); + + pctx->h_k_sid_sessid = packet_get_string(&pctx->h_k_sid_sessid_len); + packet_check_eom(); + + 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 */ + +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, Key *k, sign_cb_fn *sign_callback) +sign_and_send_pubkey(Authctxt *authctxt, Identity *id) { Buffer b; u_char *blob, *signature; u_int bloblen, slen; - int skip = 0; + u_int skip = 0; int ret = -1; int have_sig = 1; debug3("sign_and_send_pubkey"); - if (key_to_blob(k, &blob, &bloblen) == 0) { + if (key_to_blob(id->key, &blob, &bloblen) == 0) { /* we cannot handle this key */ debug3("sign_and_send_pubkey: cannot handle key"); return 0; @@ -934,12 +1321,12 @@ sign_and_send_pubkey(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback) } else { buffer_put_cstring(&b, authctxt->method->name); buffer_put_char(&b, have_sig); - buffer_put_cstring(&b, key_ssh_name(k)); + buffer_put_cstring(&b, key_ssh_name(id->key)); } buffer_put_string(&b, blob, bloblen); /* generate signature */ - ret = (*sign_callback)(authctxt, k, &signature, &slen, + ret = identity_sign(id, &signature, &slen, buffer_ptr(&b), buffer_len(&b)); if (ret == -1) { xfree(blob); @@ -959,7 +1346,7 @@ sign_and_send_pubkey(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback) buffer_put_cstring(&b, authctxt->method->name); buffer_put_char(&b, have_sig); if (!(datafellows & SSH_BUG_PKAUTH)) - buffer_put_cstring(&b, key_ssh_name(k)); + buffer_put_cstring(&b, key_ssh_name(id->key)); buffer_put_string(&b, blob, bloblen); } xfree(blob); @@ -983,23 +1370,19 @@ sign_and_send_pubkey(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback) } static int -send_pubkey_test(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback, - int hint) +send_pubkey_test(Authctxt *authctxt, Identity *id) { u_char *blob; u_int bloblen, have_sig = 0; debug3("send_pubkey_test"); - if (key_to_blob(k, &blob, &bloblen) == 0) { + if (key_to_blob(id->key, &blob, &bloblen) == 0) { /* we cannot handle this key */ debug3("send_pubkey_test: cannot handle key"); return 0; } /* register callback for USERAUTH_PK_OK message */ - authctxt->last_key_sign = sign_callback; - authctxt->last_key_hint = hint; - authctxt->last_key = k; dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok); packet_start(SSH2_MSG_USERAUTH_REQUEST); @@ -1008,7 +1391,7 @@ send_pubkey_test(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback, packet_put_cstring(authctxt->method->name); packet_put_char(have_sig); if (!(datafellows & SSH_BUG_PKAUTH)) - packet_put_cstring(key_ssh_name(k)); + packet_put_cstring(key_ssh_name(id->key)); packet_put_string(blob, bloblen); xfree(blob); packet_send(); @@ -1020,14 +1403,16 @@ load_identity_file(char *filename) { Key *private; char prompt[300], *passphrase; - int quit, i; + int perm_ok, 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); + 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; @@ -1036,8 +1421,8 @@ load_identity_file(char *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); + private = key_load_private_type(KEY_UNSPEC, + filename, passphrase, NULL, NULL); quit = 0; } else { debug2("no passphrase given, try next key"); @@ -1053,103 +1438,133 @@ load_identity_file(char *filename) return private; } -static int -identity_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, u_int *lenp, - u_char *data, u_int datalen) -{ - Key *private; - int idx, ret; - - idx = authctxt->last_key_hint; - if (idx < 0) - return -1; - - /* private key is stored in external hardware */ - if (options.identity_keys[idx]->flags & KEY_FLAG_EXT) - return key_sign(options.identity_keys[idx], sigp, lenp, data, datalen); - - private = load_identity_file(options.identity_files[idx]); - if (private == NULL) - return -1; - ret = key_sign(private, sigp, lenp, data, datalen); - key_free(private); - return ret; -} - -static int -agent_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, u_int *lenp, - u_char *data, u_int datalen) -{ - return ssh_agent_sign(authctxt->agent, key, sigp, lenp, data, datalen); -} - -static int -key_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, u_int *lenp, - u_char *data, u_int datalen) +/* + * try keys in the following order: + * 1. agent keys that are found in the config file + * 2. other agent keys + * 3. keys that are only listed in the config file + */ +static void +pubkey_prepare(Authctxt *authctxt) { - return key_sign(key, sigp, lenp, data, datalen); + Identity *id; + Idlist agent, files, *preferred; + Key *key; + AuthenticationConnection *ac; + char *comment; + int i, found; + + TAILQ_INIT(&agent); /* keys from the agent */ + TAILQ_INIT(&files); /* keys from the config file */ + preferred = &authctxt->keys; + TAILQ_INIT(preferred); /* preferred order of keys */ + + /* list of keys stored in the filesystem */ + for (i = 0; i < options.num_identity_files; i++) { + key = options.identity_keys[i]; + if (key && key->type == KEY_RSA1) + continue; + options.identity_keys[i] = NULL; + id = 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); + } } -static int -userauth_pubkey_agent(Authctxt *authctxt) +static void +pubkey_cleanup(Authctxt *authctxt) { - static int called = 0; - int ret = 0; - char *comment; - Key *k; - - if (called == 0) { - if (ssh_get_num_identities(authctxt->agent, 2) == 0) - debug2("userauth_pubkey_agent: no keys at all"); - called = 1; + 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); } - k = ssh_get_next_identity(authctxt->agent, &comment, 2); - if (k == NULL) { - debug2("userauth_pubkey_agent: no more keys"); - } else { - debug("Offering agent key: %s", comment); - xfree(comment); - ret = send_pubkey_test(authctxt, k, agent_sign_cb, -1); - if (ret == 0) - key_free(k); - } - if (ret == 0) - debug2("userauth_pubkey_agent: no message sent"); - return ret; } int userauth_pubkey(Authctxt *authctxt) { - static int idx = 0; + Identity *id; int sent = 0; - Key *key; - char *filename; - - if (authctxt->agent != NULL) { - do { - sent = userauth_pubkey_agent(authctxt); - } while (!sent && authctxt->agent->howmany > 0); - } - while (!sent && idx < options.num_identity_files) { - key = options.identity_keys[idx]; - filename = options.identity_files[idx]; - if (key == NULL) { - debug("Trying private key: %s", filename); - key = load_identity_file(filename); - if (key != NULL) { - sent = sign_and_send_pubkey(authctxt, key, - key_sign_cb); - key_free(key); + + while ((id = TAILQ_FIRST(&authctxt->keys))) { + if (id->tried++) + return (0); + /* 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; } - } else if (key->type != KEY_RSA1) { - debug("Offering public key: %s", filename); - sent = send_pubkey_test(authctxt, key, - identity_sign_cb, idx); } - idx++; + if (sent) + return (sent); } - return sent; + return (0); } /* @@ -1205,9 +1620,9 @@ input_userauth_info_req(int type, u_int32_t seq, void *ctxt) inst = packet_get_string(NULL); lang = packet_get_string(NULL); if (strlen(name) > 0) - log("%s", name); + logit("%s", name); if (strlen(inst) > 0) - log("%s", inst); + logit("%s", inst); xfree(name); xfree(inst); xfree(lang); @@ -1270,8 +1685,7 @@ ssh_keysign(Key *key, u_char **sigp, u_int *lenp, return -1; } if (pid == 0) { - seteuid(getuid()); - setuid(getuid()); + permanently_drop_suid(getuid()); close(from[0]); if (dup2(from[1], STDOUT_FILENO) < 0) fatal("ssh_keysign: dup2: %s", strerror(errno)); @@ -1290,11 +1704,12 @@ ssh_keysign(Key *key, u_char **sigp, u_int *lenp, 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_send(to[1], version, &b) == -1) + fatal("ssh_keysign: couldn't send request"); if (ssh_msg_recv(from[0], &b) < 0) { error("ssh_keysign: no reply"); - buffer_clear(&b); + buffer_free(&b); return -1; } close(from[0]); @@ -1306,11 +1721,11 @@ ssh_keysign(Key *key, u_char **sigp, u_int *lenp, if (buffer_get_char(&b) != version) { error("ssh_keysign: bad version"); - buffer_clear(&b); + buffer_free(&b); return -1; } *sigp = buffer_get_string(&b, lenp); - buffer_clear(&b); + buffer_free(&b); return 0; } @@ -1322,7 +1737,7 @@ userauth_hostbased(Authctxt *authctxt) Sensitive *sensitive = authctxt->sensitive; Buffer b; u_char *signature, *blob; - char *chost, *pkalg, *p; + char *chost, *pkalg, *p, myname[NI_MAXHOST]; const char *service; u_int blen, slen; int ok, i, len, found = 0; @@ -1346,16 +1761,24 @@ userauth_hostbased(Authctxt *authctxt) return 0; } /* figure out a name for the client host */ - p = get_local_name(packet_get_connection_in()); + 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; } len = strlen(p) + 2; - chost = xmalloc(len); - strlcpy(chost, p, len); - strlcat(chost, ".", len); + xasprintf(&chost, "%s.", p); debug2("userauth_hostbased: chost %s", chost); xfree(p); @@ -1388,6 +1811,7 @@ userauth_hostbased(Authctxt *authctxt) error("key_sign failed"); xfree(chost); xfree(pkalg); + xfree(blob); return 0; } packet_start(SSH2_MSG_USERAUTH_REQUEST); @@ -1403,11 +1827,82 @@ userauth_hostbased(Authctxt *authctxt) 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); + + return 1; +} + +void +userauth_jpake_cleanup(Authctxt *authctxt) +{ + debug3("%s: clean up", __func__); + if (authctxt->methoddata != NULL) { + jpake_free(authctxt->methoddata); + authctxt->methoddata = NULL; + } +} +#endif /* JPAKE */ + /* find auth method */ /* @@ -1509,3 +2004,4 @@ authmethods_get(void) buffer_free(&b); return list; } +