diff options
| -rw-r--r-- | ChangeLog | 10 | ||||
| -rw-r--r-- | auth.h | 3 | ||||
| -rw-r--r-- | auth2-gss.c | 243 | ||||
| -rw-r--r-- | auth2.c | 18 | ||||
| -rw-r--r-- | compat.c | 8 | ||||
| -rw-r--r-- | compat.h | 3 | ||||
| -rw-r--r-- | gss-genr.c | 256 | ||||
| -rw-r--r-- | gss-serv-krb5.c | 168 | ||||
| -rw-r--r-- | gss-serv.c | 291 | ||||
| -rw-r--r-- | monitor.c | 92 | ||||
| -rw-r--r-- | monitor.h | 5 | ||||
| -rw-r--r-- | monitor_wrap.c | 73 | ||||
| -rw-r--r-- | monitor_wrap.h | 10 | ||||
| -rw-r--r-- | readconf.c | 26 | ||||
| -rw-r--r-- | readconf.h | 4 | ||||
| -rw-r--r-- | servconf.c | 24 | ||||
| -rw-r--r-- | servconf.h | 4 | ||||
| -rw-r--r-- | session.c | 31 | ||||
| -rw-r--r-- | session.h | 5 | ||||
| -rw-r--r-- | ssh-gss.h | 109 | ||||
| -rw-r--r-- | ssh_config.5 | 14 | ||||
| -rw-r--r-- | sshconnect2.c | 252 | ||||
| -rw-r--r-- | sshd_config | 6 | ||||
| -rw-r--r-- | sshd_config.5 | 15 |
24 files changed, 1646 insertions, 24 deletions
@@ -2,6 +2,14 @@ - (djm) Bug #629: Mark ssh_config option "pamauthenticationviakbdint" as deprecated. Remove mention from README.privsep. Patch from aet AT cc.hut.fi + - (dtucker) OpenBSD CVS Sync + - markus@cvs.openbsd.org 2003/08/22 10:56:09 + [auth2.c auth2-gss.c auth.h compat.c compat.h gss-genr.c gss-serv-krb5.c + gss-serv.c monitor.c monitor.h monitor_wrap.c monitor_wrap.h readconf.c + readconf.h servconf.c servconf.h session.c session.h ssh-gss.h + ssh_config.5 sshconnect2.c sshd_config sshd_config.5] + support GSS API user authentication; patches from Simon Wilkinson, + stripped down and tested by Jakob and myself. 20030825 - (djm) Bug #621: Select OpenSC keys by usage attributes. Patch from @@ -874,4 +882,4 @@ - Fix sshd BindAddress and -b options for systems using fake-getaddrinfo. Report from murple@murple.net, diagnosis from dtucker@zip.com.au -$Id: ChangeLog,v 1.2906 2003/08/26 00:48:14 djm Exp $ +$Id: ChangeLog,v 1.2907 2003/08/26 01:49:55 dtucker Exp $ @@ -1,4 +1,4 @@ -/* $OpenBSD: auth.h,v 1.43 2003/07/22 13:35:22 markus Exp $ */ +/* $OpenBSD: auth.h,v 1.44 2003/08/22 10:56:08 markus Exp $ */ /* * Copyright (c) 2000 Markus Friedl. All rights reserved. @@ -67,6 +67,7 @@ struct Authctxt { krb5_principal krb5_user; char *krb5_ticket_file; #endif + void *methoddata; }; /* * Every authentication method has to handle authentication requests for diff --git a/auth2-gss.c b/auth2-gss.c new file mode 100644 index 00000000..c7651112 --- /dev/null +++ b/auth2-gss.c @@ -0,0 +1,243 @@ +/* $OpenBSD: auth2-gss.c,v 1.1 2003/08/22 10:56:08 markus Exp $ */ + +/* + * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include "includes.h" + +#ifdef GSSAPI + +#include "auth.h" +#include "ssh2.h" +#include "xmalloc.h" +#include "log.h" +#include "dispatch.h" +#include "servconf.h" +#include "compat.h" +#include "packet.h" +#include "monitor_wrap.h" + +#include "ssh-gss.h" + +extern ServerOptions options; + +static void input_gssapi_token(int type, u_int32_t plen, void *ctxt); +static void input_gssapi_exchange_complete(int type, u_int32_t plen, void *ctxt); +static void input_gssapi_errtok(int, u_int32_t, void *); + +/* + * We only support those mechanisms that we know about (ie ones that we know + * how to check local user kuserok and the like + */ +static int +userauth_gssapi(Authctxt *authctxt) +{ + gss_OID_desc oid = {0, NULL}; + Gssctxt *ctxt = NULL; + int mechs; + gss_OID_set supported; + int present; + OM_uint32 ms; + u_int len; + char *doid = NULL; + + if (!authctxt->valid || authctxt->user == NULL) + return (0); + + mechs = packet_get_int(); + if (mechs == 0) { + debug("Mechanism negotiation is not supported"); + return (0); + } + + ssh_gssapi_supported_oids(&supported); + do { + mechs--; + + if (doid) + xfree(doid); + + doid = packet_get_string(&len); + + if (doid[0] != SSH_GSS_OIDTYPE || doid[1] != len-2) { + logit("Mechanism OID received using the old encoding form"); + oid.elements = doid; + oid.length = len; + } else { + oid.elements = doid + 2; + oid.length = len - 2; + } + gss_test_oid_set_member(&ms, &oid, supported, &present); + } while (mechs > 0 && !present); + + gss_release_oid_set(&ms, &supported); + + if (!present) { + xfree(doid); + return (0); + } + + if (GSS_ERROR(PRIVSEP(ssh_gssapi_server_ctx(&ctxt, &oid)))) + return (0); + + authctxt->methoddata=(void *)ctxt; + + packet_start(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE); + + /* Return OID in same format as we received it*/ + packet_put_string(doid, len); + + packet_send(); + xfree(doid); + + dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token); + dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok); + authctxt->postponed = 1; + + return (0); +} + +static void +input_gssapi_token(int type, u_int32_t plen, void *ctxt) +{ + Authctxt *authctxt = ctxt; + Gssctxt *gssctxt; + gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; + gss_buffer_desc recv_tok; + OM_uint32 maj_status, min_status; + u_int len; + + if (authctxt == NULL || (authctxt->methoddata == NULL && !use_privsep)) + fatal("No authentication or GSSAPI context"); + + gssctxt = authctxt->methoddata; + recv_tok.value = packet_get_string(&len); + recv_tok.length = len; /* u_int vs. size_t */ + + packet_check_eom(); + + maj_status = PRIVSEP(ssh_gssapi_accept_ctx(gssctxt, &recv_tok, + &send_tok, NULL)); + + xfree(recv_tok.value); + + if (GSS_ERROR(maj_status)) { + if (send_tok.length != 0) { + packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK); + packet_put_string(send_tok.value, send_tok.length); + packet_send(); + } + authctxt->postponed = 0; + dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL); + userauth_finish(authctxt, 0, "gssapi"); + } else { + if (send_tok.length != 0) { + packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN); + packet_put_string(send_tok.value, send_tok.length); + packet_send(); + } + if (maj_status == GSS_S_COMPLETE) { + dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL); + dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, + &input_gssapi_exchange_complete); + } + } + + gss_release_buffer(&min_status, &send_tok); +} + +static void +input_gssapi_errtok(int type, u_int32_t plen, void *ctxt) +{ + Authctxt *authctxt = ctxt; + Gssctxt *gssctxt; + gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; + gss_buffer_desc recv_tok; + OM_uint32 maj_status; + + if (authctxt == NULL || (authctxt->methoddata == NULL && !use_privsep)) + fatal("No authentication or GSSAPI context"); + + gssctxt = authctxt->methoddata; + recv_tok.value = packet_get_string(&recv_tok.length); + + packet_check_eom(); + + /* Push the error token into GSSAPI to see what it says */ + maj_status = PRIVSEP(ssh_gssapi_accept_ctx(gssctxt, &recv_tok, + &send_tok, NULL)); + + xfree(recv_tok.value); + + /* We can't return anything to the client, even if we wanted to */ + dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL); + dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, NULL); + + /* The client will have already moved on to the next auth */ + + gss_release_buffer(&maj_status, &send_tok); +} + +/* + * This is called when the client thinks we've completed authentication. + * It should only be enabled in the dispatch handler by the function above, + * which only enables it once the GSSAPI exchange is complete. + */ + +static void +input_gssapi_exchange_complete(int type, u_int32_t plen, void *ctxt) +{ + Authctxt *authctxt = ctxt; + Gssctxt *gssctxt; + int authenticated; + + if (authctxt == NULL || (authctxt->methoddata == NULL && !use_privsep)) + fatal("No authentication or GSSAPI context"); + + gssctxt = authctxt->methoddata; + + /* + * We don't need to check the status, because the stored credentials + * which userok uses are only populated once the context init step + * has returned complete. + */ + + packet_check_eom(); + + authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user)); + + authctxt->postponed = 0; + dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL); + dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, NULL); + dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL); + userauth_finish(authctxt, authenticated, "gssapi"); +} + +Authmethod method_gssapi = { + "gssapi", + userauth_gssapi, + &options.gss_authentication +}; + +#endif /* GSSAPI */ @@ -23,7 +23,7 @@ */ #include "includes.h" -RCSID("$OpenBSD: auth2.c,v 1.99 2003/06/24 08:23:46 markus Exp $"); +RCSID("$OpenBSD: auth2.c,v 1.100 2003/08/22 10:56:08 markus Exp $"); #include "ssh2.h" #include "xmalloc.h" @@ -36,6 +36,10 @@ RCSID("$OpenBSD: auth2.c,v 1.99 2003/06/24 08:23:46 markus Exp $"); #include "pathnames.h" #include "monitor_wrap.h" +#ifdef GSSAPI +#include "ssh-gss.h" +#endif + /* import */ extern ServerOptions options; extern u_char *session_id2; @@ -53,10 +57,16 @@ extern Authmethod method_hostbased; #ifdef KRB5 extern Authmethod method_kerberos; #endif +#ifdef GSSAPI +extern Authmethod method_gssapi; +#endif Authmethod *authmethods[] = { &method_none, &method_pubkey, +#ifdef GSSAPI + &method_gssapi, +#endif &method_passwd, &method_kbdint, &method_hostbased, @@ -184,6 +194,12 @@ input_userauth_request(int type, u_int32_t seq, void *ctxt) } /* reset state */ auth2_challenge_stop(authctxt); + +#ifdef GSSAPI + dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL); + dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL); +#endif + authctxt->postponed = 0; /* try to authenticate user */ @@ -23,7 +23,7 @@ */ #include "includes.h" -RCSID("$OpenBSD: compat.c,v 1.67 2003/04/08 20:21:28 itojun Exp $"); +RCSID("$OpenBSD: compat.c,v 1.68 2003/08/22 10:56:09 markus Exp $"); #include "buffer.h" #include "packet.h" @@ -79,7 +79,11 @@ compat_datafellows(const char *version) { "OpenSSH_2.5.3*", SSH_BUG_NOREKEY|SSH_BUG_EXTEOF}, { "OpenSSH_2.*," "OpenSSH_3.0*," - "OpenSSH_3.1*", SSH_BUG_EXTEOF}, + "OpenSSH_3.1*", SSH_BUG_EXTEOF|SSH_BUG_GSSAPI_BER}, + { "OpenSSH_3.2*," + "OpenSSH_3.3*," + "OpenSSH_3.4*," + "OpenSSH_3.5*", SSH_BUG_GSSAPI_BER}, { "Sun_SSH_1.0*", SSH_BUG_NOREKEY|SSH_BUG_EXTEOF}, { "OpenSSH*", 0 }, { "*MindTerm*", 0 }, @@ -1,4 +1,4 @@ -/* $OpenBSD: compat.h,v 1.34 2003/04/01 10:31:26 markus Exp $ */ +/* $OpenBSD: compat.h,v 1.35 2003/08/22 10:56:09 markus Exp $ */ /* * Copyright (c) 1999, 2000, 2001 Markus Friedl. All rights reserved. @@ -56,6 +56,7 @@ #define SSH_BUG_K5USER 0x00400000 #define SSH_BUG_PROBE 0x00800000 #define SSH_BUG_FIRSTKEX 0x01000000 +#define SSH_BUG_GSSAPI_BER 0x02000000 void enable_compat13(void); void enable_compat20(void); diff --git a/gss-genr.c b/gss-genr.c new file mode 100644 index 00000000..bda12d6f --- /dev/null +++ b/gss-genr.c @@ -0,0 +1,256 @@ +/* $OpenBSD: gss-genr.c,v 1.1 2003/08/22 10:56:09 markus Exp $ */ + +/* + * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR `AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include "includes.h" + +#ifdef GSSAPI + +#include "xmalloc.h" +#include "bufaux.h" +#include "compat.h" +#include "log.h" +#include "monitor_wrap.h" + +#include "ssh-gss.h" + + +/* Check that the OID in a data stream matches that in the context */ +int +ssh_gssapi_check_oid(Gssctxt *ctx, void *data, size_t len) +{ + return (ctx != NULL && ctx->oid != GSS_C_NO_OID && + ctx->oid->length == len && + memcmp(ctx->oid->elements, data, len) == 0); +} + +/* Set the contexts OID from a data stream */ +void +ssh_gssapi_set_oid_data(Gssctxt *ctx, void *data, size_t len) +{ + if (ctx->oid != GSS_C_NO_OID) { + xfree(ctx->oid->elements); + xfree(ctx->oid); + } + ctx->oid = xmalloc(sizeof(gss_OID_desc)); + ctx->oid->length = len; + ctx->oid->elements = xmalloc(len); + memcpy(ctx->oid->elements, data, len); +} + +/* Set the contexts OID */ +void +ssh_gssapi_set_oid(Gssctxt *ctx, gss_OID oid) +{ + ssh_gssapi_set_oid_data(ctx, oid->elements, oid->length); +} + +/* All this effort to report an error ... */ +void +ssh_gssapi_error(Gssctxt *ctxt) +{ + debug("%s", ssh_gssapi_last_error(ctxt, NULL, NULL)); +} + +char * +ssh_gssapi_last_error(Gssctxt *ctxt, + OM_uint32 *major_status, OM_uint32 *minor_status) +{ + OM_uint32 lmin; + gss_buffer_desc msg = GSS_C_EMPTY_BUFFER; + OM_uint32 ctx; + Buffer b; + char *ret; + + buffer_init(&b); + + if (major_status != NULL) + *major_status = ctxt->major; + if (minor_status != NULL) + *minor_status = ctxt->minor; + + ctx = 0; + /* The GSSAPI error */ + do { + gss_display_status(&lmin, ctxt->major, + GSS_C_GSS_CODE, GSS_C_NULL_OID, &ctx, &msg); + + buffer_append(&b, msg.value, msg.length); + buffer_put_char(&b, '\n'); + + gss_release_buffer(&lmin, &msg); + } while (ctx != 0); + + /* The mechanism specific error */ + do { + gss_display_status(&lmin, ctxt->minor, + GSS_C_MECH_CODE, GSS_C_NULL_OID, &ctx, &msg); + + buffer_append(&b, msg.value, msg.length); + buffer_put_char(&b, '\n'); + + gss_release_buffer(&lmin, &msg); + } while (ctx != 0); + + buffer_put_char(&b, '\0'); + ret = xmalloc(buffer_len(&b)); + buffer_get(&b, ret, buffer_len(&b)); + buffer_free(&b); + return (ret); +} + +/* + * Initialise our GSSAPI context. We use this opaque structure to contain all + * of the data which both the client and server need to persist across + * {accept,init}_sec_context calls, so that when we do it from the userauth + * stuff life is a little easier + */ +void +ssh_gssapi_build_ctx(Gssctxt **ctx) +{ + *ctx = xmalloc(sizeof (Gssctxt)); + (*ctx)->major = 0; + (*ctx)->minor = 0; + (*ctx)->context = GSS_C_NO_CONTEXT; + (*ctx)->name = GSS_C_NO_NAME; + (*ctx)->oid = GSS_C_NO_OID; + (*ctx)->creds = GSS_C_NO_CREDENTIAL; + (*ctx)->client = GSS_C_NO_NAME; + (*ctx)->client_creds = GSS_C_NO_CREDENTIAL; +} + +/* Delete our context, providing it has been built correctly */ +void +ssh_gssapi_delete_ctx(Gssctxt **ctx) +{ + OM_uint32 ms; + + if ((*ctx) == NULL) + return; + if ((*ctx)->context != GSS_C_NO_CONTEXT) + gss_delete_sec_context(&ms, &(*ctx)->context, GSS_C_NO_BUFFER); + if ((*ctx)->name != GSS_C_NO_NAME) + gss_release_name(&ms, &(*ctx)->name); + if ((*ctx)->oid != GSS_C_NO_OID) { + xfree((*ctx)->oid->elements); + xfree((*ctx)->oid); + (*ctx)->oid = GSS_C_NO_OID; + } + if ((*ctx)->creds != GSS_C_NO_CREDENTIAL) + gss_release_cred(&ms, &(*ctx)->creds); + if ((*ctx)->client != GSS_C_NO_NAME) + gss_release_name(&ms, &(*ctx)->client); + if ((*ctx)->client_creds != GSS_C_NO_CREDENTIAL) + gss_release_cred(&ms, &(*ctx)->client_creds); + + xfree(*ctx); + *ctx = NULL; +} + +/* + * Wrapper to init_sec_context + * Requires that the context contains: + * oid + * server name (from ssh_gssapi_import_name) + */ +OM_uint32 +ssh_gssapi_init_ctx(Gssctxt *ctx, int deleg_creds, gss_buffer_desc *recv_tok, + gss_buffer_desc* send_tok, OM_uint32 *flags) +{ + int deleg_flag = 0; + + if (deleg_creds) { + deleg_flag = GSS_C_DELEG_FLAG; + debug("Delegating credentials"); + } + + ctx->major = gss_init_sec_context(&ctx->minor, + GSS_C_NO_CREDENTIAL, &ctx->context, ctx->name, ctx->oid, + GSS_C_MUTUAL_FLAG | GSS_C_INTEG_FLAG | deleg_flag, + 0, NULL, recv_tok, NULL, send_tok, flags, NULL); + + if (GSS_ERROR(ctx->major)) + ssh_gssapi_error(ctx); + + return (ctx->major); +} + +/* Create a service name for the given host */ +OM_uint32 +ssh_gssapi_import_name(Gssctxt *ctx, const char *host) +{ + gss_buffer_desc gssbuf; + + gssbuf.length = sizeof("host@") + strlen(host); + gssbuf.value = xmalloc(gssbuf.length); + snprintf(gssbuf.value, gssbuf.length, "host@%s", host); + + if ((ctx->major = gss_import_name(&ctx->minor, + &gssbuf, GSS_C_NT_HOSTBASED_SERVICE, &ctx->name))) + ssh_gssapi_error(ctx); + + xfree(gssbuf.value); + return (ctx->major); +} + +/* Acquire credentials for a server running on the current host. + * Requires that the context structure contains a valid OID + */ + +/* Returns a GSSAPI error code */ +OM_uint32 +ssh_gssapi_acquire_cred(Gssctxt *ctx) +{ + OM_uint32 status; + char lname[MAXHOSTNAMELEN]; + gss_OID_set oidset; + + gss_create_empty_oid_set(&status, &oidset); + gss_add_oid_set_member(&status, ctx->oid, &oidset); + + if (gethostname(lname, MAXHOSTNAMELEN)) + return (-1); + + if (GSS_ERROR(ssh_gssapi_import_name(ctx, lname))) + return (ctx->major); + + if ((ctx->major = gss_acquire_cred(&ctx->minor, + ctx->name, 0, oidset, GSS_C_ACCEPT, &ctx->creds, NULL, NULL))) + ssh_gssapi_error(ctx); + + gss_release_oid_set(&status, &oidset); + return (ctx->major); +} + +OM_uint32 +ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID oid) { + if (*ctx) + ssh_gssapi_delete_ctx(ctx); + ssh_gssapi_build_ctx(ctx); + ssh_gssapi_set_oid(*ctx, oid); + return (ssh_gssapi_acquire_cred(*ctx)); +} + +#endif /* GSSAPI */ diff --git a/gss-serv-krb5.c b/gss-serv-krb5.c new file mode 100644 index 00000000..d8687225 --- /dev/null +++ b/gss-serv-krb5.c @@ -0,0 +1,168 @@ +/* $OpenBSD: gss-serv-krb5.c,v 1.1 2003/08/22 10:56:09 markus Exp $ */ + +/* + * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR `AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include "includes.h" + +#ifdef GSSAPI +#ifdef KRB5 + +#include "auth.h" +#include "xmalloc.h" +#include "log.h" +#include "servconf.h" + +#include "ssh-gss.h" + +extern ServerOptions options; + +#include <krb5.h> + +static krb5_context krb_context = NULL; + +/* Initialise the krb5 library, for the stuff that GSSAPI won't do */ + +static int +ssh_gssapi_krb5_init() +{ + krb5_error_code problem; + + if (krb_context != NULL) + return 1; + + problem = krb5_init_context(&krb_context); + if (problem) { + logit("Cannot initialize krb5 context"); + return 0; + } + krb5_init_ets(krb_context); + + return 1; +} + +/* Check if this user is OK to login. This only works with krb5 - other + * GSSAPI mechanisms will need their own. + * Returns true if the user is OK to log in, otherwise returns 0 + */ + +static int +ssh_gssapi_krb5_userok(ssh_gssapi_client *client, char *name) +{ + krb5_principal princ; + int retval; + + if (ssh_gssapi_krb5_init() == 0) + return 0; + + if ((retval = krb5_parse_name(krb_context, client->exportedname.value, + &princ))) { + logit("krb5_parse_name(): %.100s", + krb5_get_err_text(krb_context, retval)); + return 0; + } + if (krb5_kuserok(krb_context, princ, name)) { + retval = 1; + logit("Authorized to %s, krb5 principal %s (krb5_kuserok)", + name, (char *)client->displayname.value); + } else + retval = 0; + + krb5_free_principal(krb_context, princ); + return retval; +} + + +/* This writes out any forwarded credentials from the structure populated + * during userauth. Called after we have setuid to the user */ + +static void +ssh_gssapi_krb5_storecreds(ssh_gssapi_client *client) +{ + krb5_ccache ccache; + krb5_error_code problem; + krb5_principal princ; + OM_uint32 maj_status, min_status; + + if (client->creds == NULL) { + debug("No credentials stored"); + return; + } + + if (ssh_gssapi_krb5_init() == 0) + return; + + if ((problem = krb5_cc_gen_new(krb_context, &krb5_fcc_ops, &ccache))) { + logit("krb5_cc_gen_new(): %.100s", + krb5_get_err_text(krb_context, problem)); + return; + } + + if ((problem = krb5_parse_name(krb_context, + client->exportedname.value, &princ))) { + logit("krb5_parse_name(): %.100s", + krb5_get_err_text(krb_context, problem)); + krb5_cc_destroy(krb_context, ccache); + return; + } + + if ((problem = krb5_cc_initialize(krb_context, ccache, princ))) { + logit("krb5_cc_initialize(): %.100s", + krb5_get_err_text(krb_context, problem)); + krb5_free_principal(krb_context, princ); + krb5_cc_destroy(krb_context, ccache); + return; + } + + krb5_free_principal(krb_context, princ); + + if ((maj_status = gss_krb5_copy_ccache(&min_status, + client->creds, ccache))) { + logit("gss_krb5_copy_ccache() failed"); + krb5_cc_destroy(krb_context, ccache); + return; + } + + client->store.filename = xstrdup(krb5_cc_get_name(krb_context, ccache)); + client->store.envvar = "KRB5CCNAME"; + client->store.envval = xstrdup(client->store.filename); + + krb5_cc_close(krb_context, ccache); + + return; +} + +ssh_gssapi_mech gssapi_kerberos_mech = { + "toWM5Slw5Ew8Mqkay+al2g==", + "Kerberos", + {9, "\x2A\x86\x48\x86\xF7\x12\x01\x02\x02"}, + NULL, + &ssh_gssapi_krb5_userok, + NULL, + &ssh_gssapi_krb5_storecreds +}; + +#endif /* KRB5 */ + +#endif /* GSSAPI */ diff --git a/gss-serv.c b/gss-serv.c new file mode 100644 index 00000000..42718177 --- /dev/null +++ b/gss-serv.c @@ -0,0 +1,291 @@ +/* $OpenBSD: gss-serv.c,v 1.1 2003/08/22 10:56:09 markus Exp $ */ + +/* + * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR `AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include "includes.h" + +#ifdef GSSAPI + +#include "bufaux.h" +#include "compat.h" +#include "auth.h" +#include "log.h" +#include "channels.h" +#include "session.h" +#include "servconf.h" +#include "monitor_wrap.h" +#include "xmalloc.h" +#include "getput.h" + +#include "ssh-gss.h" + +extern ServerOptions options; + +static ssh_gssapi_client gssapi_client = + { GSS_C_EMPTY_BUFFER, GSS_C_EMPTY_BUFFER, + GSS_C_NO_CREDENTIAL, NULL, {NULL, NULL, NULL}}; + +ssh_gssapi_mech gssapi_null_mech = + { NULL, NULL, {0, NULL}, NULL, NULL, NULL, NULL}; + +#ifdef KRB5 +extern ssh_gssapi_mech gssapi_kerberos_mech; +#endif + +ssh_gssapi_mech* supported_mechs[]= { +#ifdef KRB5 + &gssapi_kerberos_mech, +#endif + &gssapi_null_mech, +}; + +/* Unpriviledged */ +void +ssh_gssapi_supported_oids(gss_OID_set *oidset) +{ + int i = 0; + OM_uint32 min_status; + int present; + gss_OID_set supported; + + gss_create_empty_oid_set(&min_status, oidset); + gss_indicate_mechs(&min_status, &supported); + + while (supported_mechs[i]->name != NULL) { + if (GSS_ERROR(gss_test_oid_set_member(&min_status, + &supported_mechs[i]->oid, supported, &present))) + present = 0; + if (present) + gss_add_oid_set_member(&min_status, + &supported_mechs[i]->oid, oidset); + i++; + } +} + + +/* Wrapper around accept_sec_context + * Requires that the context contains: + * oid + * credentials (from ssh_gssapi_acquire_cred) + */ +/* Priviledged */ +OM_uint32 +ssh_gssapi_accept_ctx(Gssctxt *ctx, gss_buffer_desc *recv_tok, + gss_buffer_desc *send_tok, OM_uint32 *flags) +{ + OM_uint32 status; + gss_OID mech; + + ctx->major = gss_accept_sec_context(&ctx->minor, + &ctx->context, ctx->creds, recv_tok, + GSS_C_NO_CHANNEL_BINDINGS, &ctx->client, &mech, + send_tok, flags, NULL, &ctx->client_creds); + + if (GSS_ERROR(ctx->major)) + ssh_gssapi_error(ctx); + + if (ctx->client_creds) + debug("Received some client credentials"); + else + debug("Got no client credentials"); + + status = ctx->major; + + /* Now, if we're complete and we have the right flags, then + * we flag the user as also having been authenticated + */ + + if (((flags == NULL) || ((*flags & GSS_C_MUTUAL_FLAG) && + (*flags & GSS_C_INTEG_FLAG))) && (ctx->major == GSS_S_COMPLETE)) { + if (ssh_gssapi_getclient(ctx, &gssapi_client)) + fatal("Couldn't convert client name"); + } + + return (status); +} + +/* + * This parses an exported name, extracting the mechanism specific portion + * to use for ACL checking. It verifies that the name belongs the mechanism + * originally selected. + */ +static OM_uint32 +ssh_gssapi_parse_ename(Gssctxt *ctx, gss_buffer_t ename, gss_buffer_t name) +{ + char *tok; + OM_uint32 offset; + OM_uint32 oidl; + + tok=ename->value; + + /* + * Check that ename is long enough for all of the fixed length + * header, and that the initial ID bytes are correct + */ + + if (ename->length<6 || memcmp(tok,"\x04\x01", 2)!=0) + return GSS_S_FAILURE; + + /* + * Extract the OID, and check it. Here GSSAPI breaks with tradition + * and does use the OID type and length bytes. To confuse things + * there are two lengths - the first including these, and the + * second without. + */ + + oidl = GET_16BIT(tok+2); /* length including next two bytes */ + oidl = oidl-2; /* turn it into the _real_ length of the variable OID */ + + /* + * Check the BER encoding for correct type and length, that the + * string is long enough and that the OID matches that in our context + */ + if (tok[4] != 0x06 || tok[5] != oidl || + ename->length < oidl+6 || + !ssh_gssapi_check_oid(ctx,tok+6,oidl)) + return GSS_S_FAILURE; + + offset = oidl+6; + + if (ename->length < offset+4) + return GSS_S_FAILURE; + + name->length = GET_32BIT(tok+offset); + offset += 4; + + if (ename->length < offset+name->length) + return GSS_S_FAILURE; + + name->value = xmalloc(name->length); + memcpy(name->value,tok+offset,name->length); + + return GSS_S_COMPLETE; +} + +/* Extract the client details from a given context. This can only reliably + * be called once for a context */ + +/* Priviledged (called from accept_secure_ctx) */ +OM_uint32 +ssh_gssapi_getclient(Gssctxt *ctx, ssh_gssapi_client *client) +{ + int i = 0; + + gss_buffer_desc ename; + + client->mech = NULL; + + while (supported_mechs[i]->name != NULL) { + if (supported_mechs[i]->oid.length == ctx->oid->length && + (memcmp(supported_mechs[i]->oid.elements, + ctx->oid->elements, ctx->oid->length) == 0)) + client->mech = supported_mechs[i]; + i++; + } + + if (client->mech == NULL) + return GSS_S_FAILURE; + + if ((ctx->major = gss_display_name(&ctx->minor, ctx->client, + &client->displayname, NULL))) { + ssh_gssapi_error(ctx); + return (ctx->major); + } + + if ((ctx->major = gss_export_name(&ctx->minor, ctx->client, + &ename))) { + ssh_gssapi_error(ctx); + return (ctx->major); + } + + if ((ctx->major = ssh_gssapi_parse_ename(ctx,&ename, + &client->exportedname))) { + return (ctx->major); + } + + /* We can't copy this structure, so we just move the pointer to it */ + client->creds = ctx->client_creds; + ctx->client_creds = GSS_C_NO_CREDENTIAL; + return (ctx->major); +} + +/* As user - called through fatal cleanup hook */ +void +ssh_gssapi_cleanup_creds(void *ignored) +{ + if (gssapi_client.store.filename != NULL) { + /* Unlink probably isn't sufficient */ + debug("removing gssapi cred file\"%s\"", gssapi_client.store.filename); + unlink(gssapi_client.store.filename); + } +} + +/* As user */ +void +ssh_gssapi_storecreds(void) +{ + if (gssapi_client.mech && gssapi_client.mech->storecreds) { + (*gssapi_client.mech->storecreds)(&gssapi_client); + if (options.gss_cleanup_creds) + fatal_add_cleanup(ssh_gssapi_cleanup_creds, NULL); + } else + debug("ssh_gssapi_storecreds: Not a GSSAPI mechanism"); +} + +/* This allows GSSAPI methods to do things to the childs environment based + * on the passed authentication process and credentials. + */ +/* As user */ +void +ssh_gssapi_do_child(char ***envp, u_int *envsizep) +{ + + if (gssapi_client.store.envvar != NULL && + gssapi_client.store.envval != NULL) { + + debug("Setting %s to %s", gssapi_client.store.envvar, + gssapi_client.store.envval); + child_set_env(envp, envsizep, gssapi_client.store.envvar, + gssapi_client.store.envval); + } +} + +/* Priviledged */ +int +ssh_gssapi_userok(char *user) +{ + if (gssapi_client.exportedname.length == 0 || + gssapi_client.exportedname.value == NULL) { + debug("No suitable client data"); + return 0; + } + if (gssapi_client.mech && gssapi_client.mech->userok) + return ((*gssapi_client.mech->userok)(&gssapi_client, user)); + else + debug("ssh_gssapi_userok: Unknown GSSAPI mechanism"); + return (0); +} + +#endif @@ -25,7 +25,7 @@ */ #include "includes.h" -RCSID("$OpenBSD: monitor.c,v 1.45 2003/07/22 13:35:22 markus Exp $"); +RCSID("$OpenBSD: monitor.c,v 1.46 2003/08/22 10:56:09 markus Exp $"); #include <openssl/dh.h> @@ -59,6 +59,11 @@ RCSID("$OpenBSD: monitor.c,v 1.45 2003/07/22 13:35:22 markus Exp $"); #include "ssh2.h" #include "mpaux.h" +#ifdef GSSAPI +#include "ssh-gss.h" +static Gssctxt *gsscontext = NULL; +#endif + /* Imports */ extern ServerOptions options; extern u_int utmp_len; @@ -128,6 +133,11 @@ int mm_answer_pam_free_ctx(int, Buffer *); #ifdef KRB5 int mm_answer_krb5(int, Buffer *); #endif +#ifdef GSSAPI +int mm_answer_gss_setup_ctx(int, Buffer *); +int mm_answer_gss_accept_ctx(int, Buffer *); +int mm_answer_gss_userok(int, Buffer *); +#endif static Authctxt *authctxt; static BIGNUM *ssh1_challenge = NULL; /* used for ssh1 rsa auth */ @@ -185,6 +195,11 @@ struct mon_table mon_dispatch_proto20[] = { #ifdef KRB5 {MONITOR_REQ_KRB5, MON_ONCE|MON_AUTH, mm_answer_krb5}, #endif +#ifdef GSSAPI + {MONITOR_REQ_GSSSETUP, MON_ISAUTH, mm_answer_gss_setup_ctx}, + {MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx}, + {MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok}, +#endif {0, 0, NULL} }; @@ -357,7 +372,6 @@ monitor_child_postauth(struct monitor *pmonitor) monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1); monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1); monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); - } else { mon_dispatch = mon_dispatch_postauth15; monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1); @@ -1769,3 +1783,77 @@ monitor_reinit(struct monitor *mon) mon->m_recvfd = pair[0]; mon->m_sendfd = pair[1]; } + +#ifdef GSSAPI +int +mm_answer_gss_setup_ctx(int socket, Buffer *m) +{ + gss_OID_desc oid; + OM_uint32 major; + u_int len; + + oid.elements = buffer_get_string(m, &len); + oid.length = len; + + major = ssh_gssapi_server_ctx(&gsscontext, &oid); + + xfree(oid.elements); + + buffer_clear(m); + buffer_put_int(m, major); + + mm_request_send(socket,MONITOR_ANS_GSSSETUP, m); + + /* Now we have a context, enable the step */ + monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 1); + + return (0); +} + +int +mm_answer_gss_accept_ctx(int socket, Buffer *m) +{ + gss_buffer_desc in; + gss_buffer_desc out = GSS_C_EMPTY_BUFFER; + OM_uint32 major,minor; + OM_uint32 flags = 0; /* GSI needs this */ + + in.value = buffer_get_string(m, &in.length); + major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags); + xfree(in.value); + + buffer_clear(m); + buffer_put_int(m, major); + buffer_put_string(m, out.value, out.length); + buffer_put_int(m, flags); + mm_request_send(socket, MONITOR_ANS_GSSSTEP, m); + + gss_release_buffer(&minor, &out); + + /* Complete - now we can do signing */ + if (major==GSS_S_COMPLETE) { + monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0); + monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1); + } + return (0); +} + +int +mm_answer_gss_userok(int socket, Buffer *m) +{ + int authenticated; + + authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user); + + buffer_clear(m); + buffer_put_int(m, authenticated); + + debug3("%s: sending result %d", __func__, authenticated); + mm_request_send(socket, MONITOR_ANS_GSSUSEROK, m); + + auth_method="gssapi"; + + /* Monitor loop will terminate if authenticated */ + return (authenticated); +} +#endif /* GSSAPI */ @@ -1,4 +1,4 @@ -/* $OpenBSD: monitor.h,v 1.9 2003/07/22 13:35:22 markus Exp $ */ +/* $OpenBSD: monitor.h,v 1.10 2003/08/22 10:56:09 markus Exp $ */ /* * Copyright 2002 Niels Provos <provos@citi.umich.edu> @@ -50,6 +50,9 @@ enum monitor_reqtype { MONITOR_REQ_RSACHALLENGE, MONITOR_ANS_RSACHALLENGE, MONITOR_REQ_RSARESPONSE, MONITOR_ANS_RSARESPONSE, MONITOR_REQ_KRB5, MONITOR_ANS_KRB5, + MONITOR_REQ_GSSSETUP, MONITOR_ANS_GSSSETUP, + MONITOR_REQ_GSSSTEP, MONITOR_ANS_GSSSTEP, + MONITOR_REQ_GSSUSEROK, MONITOR_ANS_GSSUSEROK, MONITOR_REQ_PAM_START, MONITOR_REQ_PAM_ACCOUNT, MONITOR_ANS_PAM_ACCOUNT, MONITOR_REQ_PAM_INIT_CTX, MONITOR_ANS_PAM_INIT_CTX, diff --git a/monitor_wrap.c b/monitor_wrap.c index 9e7e6b3c..4073905f 100644 --- a/monitor_wrap.c +++ b/monitor_wrap.c @@ -25,7 +25,7 @@ */ #include "includes.h" -RCSID("$OpenBSD: monitor_wrap.c,v 1.28 2003/07/22 13:35:22 markus Exp $"); +RCSID("$OpenBSD: monitor_wrap.c,v 1.29 2003/08/22 10:56:09 markus Exp $"); #include <openssl/bn.h> #include <openssl/dh.h> @@ -53,6 +53,10 @@ RCSID("$OpenBSD: monitor_wrap.c,v 1.28 2003/07/22 13:35:22 markus Exp $"); #include "channels.h" #include "session.h" +#ifdef GSSAPI +#include "ssh-gss.h" +#endif + /* Imports */ extern int compat20; extern Newkeys *newkeys[]; @@ -1100,4 +1104,69 @@ mm_auth_krb5(void *ctx, void *argp, char **userp, void *resp) buffer_free(&m); return (success); } -#endif +#endif /* KRB5 */ + +#ifdef GSSAPI +OM_uint32 +mm_ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID oid) +{ + Buffer m; + OM_uint32 major; + + /* Client doesn't get to see the context */ + *ctx = NULL; + + buffer_init(&m); + buffer_put_string(&m, oid->elements, oid->length); + + mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSETUP, &m); + mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSETUP, &m); + + major = buffer_get_int(&m); + + buffer_free(&m); + return (major); +} + +OM_uint32 +mm_ssh_gssapi_accept_ctx(Gssctxt *ctx, gss_buffer_desc *in, + gss_buffer_desc *out, OM_uint32 *flags) +{ + Buffer m; + OM_uint32 major; + + buffer_init(&m); + buffer_put_string(&m, in->value, in->length); + + mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSTEP, &m); + mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSTEP, &m); + + major = buffer_get_int(&m); + out->value = buffer_get_string(&m, &out->length); + if (flags) + *flags = buffer_get_int(&m); + + buffer_free(&m); + + return (major); +} + +int +mm_ssh_gssapi_userok(char *user) +{ + Buffer m; + int authenticated = 0; + + buffer_init(&m); + + mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSUSEROK, &m); + mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSUSEROK, + &m); + + authenticated = buffer_get_int(&m); + + buffer_free(&m); + debug3("%s: user %sauthenticated",__func__, authenticated ? "" : "not "); + return (authenticated); +} +#endif /* GSSAPI */ diff --git a/monitor_wrap.h b/monitor_wrap.h index ddd42ee2..c6251924 100644 --- a/monitor_wrap.h +++ b/monitor_wrap.h @@ -1,4 +1,4 @@ -/* $OpenBSD: monitor_wrap.h,v 1.9 2003/07/22 13:35:22 markus Exp $ */ +/* $OpenBSD: monitor_wrap.h,v 1.10 2003/08/22 10:56:09 markus Exp $ */ /* * Copyright 2002 Niels Provos <provos@citi.umich.edu> @@ -55,6 +55,14 @@ int mm_auth_rsa_key_allowed(struct passwd *, BIGNUM *, Key **); int mm_auth_rsa_verify_response(Key *, BIGNUM *, u_char *); BIGNUM *mm_auth_rsa_generate_challenge(Key *); +#ifdef GSSAPI +#include "ssh-gss.h" +OM_uint32 mm_ssh_gssapi_server_ctx(Gssctxt **ctxt, gss_OID oid); +OM_uint32 mm_ssh_gssapi_accept_ctx(Gssctxt *ctxt, + gss_buffer_desc *recv, gss_buffer_desc *send, OM_uint32 *flags); +int mm_ssh_gssapi_userok(char *user); +#endif + #ifdef USE_PAM void mm_start_pam(char *); u_int mm_do_pam_account(void); @@ -12,7 +12,7 @@ */ #include "includes.h" -RCSID("$OpenBSD: readconf.c,v 1.117 2003/08/13 09:07:09 markus Exp $"); +RCSID("$OpenBSD: readconf.c,v 1.118 2003/08/22 10:56:09 markus Exp $"); #include "ssh.h" #include "xmalloc.h" @@ -105,7 +105,7 @@ typedef enum { oHostKeyAlgorithms, oBindAddress, oSmartcardDevice, oClearAllForwardings, oNoHostAuthenticationForLocalhost, oEnableSSHKeysign, oRekeyLimit, oVerifyHostKeyDNS, oConnectTimeout, - oAddressFamily, + oAddressFamily, oGssAuthentication, oGssDelegateCreds, oDeprecated, oUnsupported } OpCodes; @@ -140,6 +140,14 @@ static struct { { "kerberostgtpassing", oUnsupported }, #endif { "afstokenpassing", oUnsupported }, +#if defined(GSSAPI) + { "gssapiauthentication", oGssAuthentication }, + { "gssapidelegatecreds", oGssDelegateCreds }, + { "gssapidelegatecredentials", oGssDelegateCreds }, +#else + { "gssapiauthentication", oUnsupported }, + { "gssapidelegatecredentials", oUnsupported }, +#endif { "fallbacktorsh", oDeprecated }, { "usersh", oDeprecated }, { "identityfile", oIdentityFile }, @@ -389,6 +397,14 @@ parse_flag: intptr = &options->kerberos_tgt_passing; goto parse_flag; + case oGssAuthentication: + intptr = &options->gss_authentication; + goto parse_flag; + + case oGssDelegateCreds: + intptr = &options->gss_deleg_creds; + goto parse_flag; + case oBatchMode: intptr = &options->batch_mode; goto parse_flag; @@ -813,6 +829,8 @@ initialize_options(Options * options) options->challenge_response_authentication = -1; options->kerberos_authentication = -1; options->kerberos_tgt_passing = -1; + options->gss_authentication = -1; + options->gss_deleg_creds = -1; options->password_authentication = -1; options->kbd_interactive_authentication = -1; options->kbd_interactive_devices = NULL; @@ -887,6 +905,10 @@ fill_default_options(Options * options) options->kerberos_authentication = 1; if (options->kerberos_tgt_passing == -1) options->kerberos_tgt_passing = 1; + if (options->gss_authentication == -1) + options->gss_authentication = 1; + if (options->gss_deleg_creds == -1) + options->gss_deleg_creds = 0; if (options->password_authentication == -1) options->password_authentication = 1; if (options->kbd_interactive_authentication == -1) @@ -1,4 +1,4 @@ -/* $OpenBSD: readconf.h,v 1.53 2003/08/13 08:46:30 markus Exp $ */ +/* $OpenBSD: readconf.h,v 1.54 2003/08/22 10:56:09 markus Exp $ */ /* * Author: Tatu Ylonen <ylo@cs.hut.fi> @@ -42,6 +42,8 @@ typedef struct { /* Try S/Key or TIS, authentication. */ int kerberos_authentication; /* Try Kerberos authentication. */ int kerberos_tgt_passing; /* Try Kerberos TGT passing. */ + int gss_authentication; /* Try GSS authentication */ + int gss_deleg_creds; /* Delegate GSS credentials */ int password_authentication; /* Try password * authentication. */ int kbd_interactive_authentication; /* Try keyboard-interactive auth. */ @@ -10,7 +10,7 @@ */ #include "includes.h" -RCSID("$OpenBSD: servconf.c,v 1.124 2003/08/13 08:46:30 markus Exp $"); +RCSID("$OpenBSD: servconf.c,v 1.125 2003/08/22 10:56:09 markus Exp $"); #include "ssh.h" #include "log.h" @@ -73,6 +73,8 @@ initialize_server_options(ServerOptions *options) options->kerberos_or_local_passwd = -1; options->kerberos_ticket_cleanup = -1; options->kerberos_tgt_passing = -1; + options->gss_authentication=-1; + options->gss_cleanup_creds = -1; options->password_authentication = -1; options->kbd_interactive_authentication = -1; options->challenge_response_authentication = -1; @@ -182,6 +184,10 @@ fill_default_server_options(ServerOptions *options) options->kerberos_ticket_cleanup = 1; if (options->kerberos_tgt_passing == -1) options->kerberos_tgt_passing = 0; + if (options->gss_authentication == -1) + options->gss_authentication = 0; + if (options->gss_cleanup_creds == -1) + options->gss_cleanup_creds = 1; if (options->password_authentication == -1) options->password_authentication = 1; if (options->kbd_interactive_authentication == -1) @@ -259,6 +265,7 @@ typedef enum { sBanner, sUseDNS, sHostbasedAuthentication, sHostbasedUsesNameFromPacketOnly, sClientAliveInterval, sClientAliveCountMax, sAuthorizedKeysFile, sAuthorizedKeysFile2, + sGssAuthentication, sGssCleanupCreds, sUsePrivilegeSeparation, sDeprecated, sUnsupported } ServerOpCodes; @@ -305,6 +312,13 @@ static struct { { "kerberostgtpassing", sUnsupported }, #endif { "afstokenpassing", sUnsupported }, +#ifdef GSSAPI + { "gssapiauthentication", sGssAuthentication }, + { "gssapicleanupcreds", sGssCleanupCreds }, +#else + { "gssapiauthentication", sUnsupported }, + { "gssapicleanupcreds", sUnsupported }, +#endif { "passwordauthentication", sPasswordAuthentication }, { "kbdinteractiveauthentication", sKbdInteractiveAuthentication }, { "challengeresponseauthentication", sChallengeResponseAuthentication }, @@ -623,6 +637,14 @@ parse_flag: intptr = &options->kerberos_tgt_passing; goto parse_flag; + case sGssAuthentication: + intptr = &options->gss_authentication; + goto parse_flag; + + case sGssCleanupCreds: + intptr = &options->gss_cleanup_creds; + goto parse_flag; + case sPasswordAuthentication: intptr = &options->password_authentication; goto parse_flag; @@ -1,4 +1,4 @@ -/* $OpenBSD: servconf.h,v 1.63 2003/08/13 08:46:30 markus Exp $ */ +/* $OpenBSD: servconf.h,v 1.64 2003/08/22 10:56:09 markus Exp $ */ /* * Author: Tatu Ylonen <ylo@cs.hut.fi> @@ -82,6 +82,8 @@ typedef struct { * file on logout. */ int kerberos_tgt_passing; /* If true, permit Kerberos TGT * passing. */ + int gss_authentication; /* If true, permit GSSAPI authentication */ + int gss_cleanup_creds; /* If true, destroy cred cache on logout */ int password_authentication; /* If true, permit password * authentication. */ int kbd_interactive_authentication; /* If true, permit */ @@ -33,7 +33,7 @@ */ #include "includes.h" -RCSID("$OpenBSD: session.c,v 1.160 2003/08/13 08:33:02 markus Exp $"); +RCSID("$OpenBSD: session.c,v 1.161 2003/08/22 10:56:09 markus Exp $"); #include "ssh.h" #include "ssh1.h" @@ -58,6 +58,10 @@ RCSID("$OpenBSD: session.c,v 1.160 2003/08/13 08:33:02 markus Exp $"); #include "session.h" #include "monitor_wrap.h" +#ifdef GSSAPI +#include "ssh-gss.h" +#endif + /* func */ Session *session_new(void); @@ -424,6 +428,12 @@ do_exec_no_pty(Session *s, const char *command) } #endif /* USE_PAM */ +#ifdef GSSAPI + temporarily_use_uid(s->pw); + ssh_gssapi_storecreds(); + restore_uid(); +#endif + /* Fork the child. */ if ((pid = fork()) == 0) { fatal_remove_all_cleanups(); @@ -550,6 +560,12 @@ do_exec_pty(Session *s, const char *command) } #endif +#ifdef GSSAPI + temporarily_use_uid(s->pw); + ssh_gssapi_storecreds(); + restore_uid(); +#endif + /* Fork the child. */ if ((pid = fork()) == 0) { fatal_remove_all_cleanups(); @@ -807,7 +823,7 @@ check_quietlogin(Session *s, const char *command) * Sets the value of the given variable in the environment. If the variable * already exists, its value is overriden. */ -static void +void child_set_env(char ***envp, u_int *envsizep, const char *name, const char *value) { @@ -934,6 +950,13 @@ do_setup_env(Session *s, const char *shell) copy_environment(environ, &env, &envsize); #endif +#ifdef GSSAPI + /* Allow any GSSAPI methods that we've used to alter + * the childs environment as they see fit + */ + ssh_gssapi_do_child(&env, &envsize); +#endif + if (!options.use_login) { /* Set basic environment. */ child_set_env(&env, &envsize, "USER", pw->pw_name); @@ -2088,4 +2111,8 @@ static void do_authenticated2(Authctxt *authctxt) { server_loop2(authctxt); +#if defined(GSSAPI) + if (options.gss_cleanup_creds) + ssh_gssapi_cleanup_creds(NULL); +#endif } @@ -1,4 +1,4 @@ -/* $OpenBSD: session.h,v 1.19 2002/06/30 21:59:45 deraadt Exp $ */ +/* $OpenBSD: session.h,v 1.20 2003/08/22 10:56:09 markus Exp $ */ /* * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. @@ -68,4 +68,7 @@ Session *session_new(void); Session *session_by_tty(char *); void session_close(Session *); void do_setusercontext(struct passwd *); +void child_set_env(char ***envp, u_int *envsizep, const char *name, + const char *value); + #endif diff --git a/ssh-gss.h b/ssh-gss.h new file mode 100644 index 00000000..263e51b9 --- /dev/null +++ b/ssh-gss.h @@ -0,0 +1,109 @@ +/* + * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR `AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#ifndef _SSH_GSS_H +#define _SSH_GSS_H + +#ifdef GSSAPI + +#include "buffer.h" + +#include <gssapi.h> + +/* draft-ietf-secsh-gsskeyex-06 */ +#define SSH2_MSG_USERAUTH_GSSAPI_RESPONSE 60 +#define SSH2_MSG_USERAUTH_GSSAPI_TOKEN 61 +#define SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE 63 +#define SSH2_MSG_USERAUTH_GSSAPI_ERROR 64 +#define SSH2_MSG_USERAUTH_GSSAPI_ERRTOK 65 + +#define SSH_GSS_OIDTYPE 0x06 + +typedef struct { + char *filename; + char *envvar; + char *envval; + void *data; +} ssh_gssapi_ccache; + +typedef struct { + gss_buffer_desc displayname; + gss_buffer_desc exportedname; + gss_cred_id_t creds; + struct ssh_gssapi_mech_struct *mech; + ssh_gssapi_ccache store; +} ssh_gssapi_client; + +typedef struct ssh_gssapi_mech_struct { + char *enc_name; + char *name; + gss_OID_desc oid; + int (*dochild) (ssh_gssapi_client *); + int (*userok) (ssh_gssapi_client *, char *); + int (*localname) (ssh_gssapi_client *, char **); + void (*storecreds) (ssh_gssapi_client *); +} ssh_gssapi_mech; + +typedef struct { + OM_uint32 major; /* both */ + OM_uint32 minor; /* both */ + gss_ctx_id_t context; /* both */ + gss_name_t name; /* both */ + gss_OID oid; /* client */ + gss_cred_id_t creds; /* server */ + gss_name_t client; /* server */ + gss_cred_id_t client_creds; /* server */ +} Gssctxt; + +extern ssh_gssapi_mech *supported_mechs[]; + +int ssh_gssapi_check_oid(Gssctxt *ctx, void *data, size_t len); +void ssh_gssapi_set_oid_data(Gssctxt *ctx, void *data, size_t len); +void ssh_gssapi_set_oid(Gssctxt *ctx, gss_OID oid); +void ssh_gssapi_supported_oids(gss_OID_set *oidset); +ssh_gssapi_mech *ssh_gssapi_get_ctype(Gssctxt *ctxt); + +OM_uint32 ssh_gssapi_import_name(Gssctxt *ctx, const char *host); +OM_uint32 ssh_gssapi_acquire_cred(Gssctxt *ctx); +OM_uint32 ssh_gssapi_init_ctx(Gssctxt *ctx, int deleg_creds, + gss_buffer_desc *recv_tok, gss_buffer_desc *send_tok, OM_uint32 *flags); +OM_uint32 ssh_gssapi_accept_ctx(Gssctxt *ctx, + gss_buffer_desc *recv_tok, gss_buffer_desc *send_tok, OM_uint32 *flags); +OM_uint32 ssh_gssapi_getclient(Gssctxt *ctx, ssh_gssapi_client *); +void ssh_gssapi_error(Gssctxt *ctx); +char *ssh_gssapi_last_error(Gssctxt *ctxt, OM_uint32 *maj, OM_uint32 *min); +void ssh_gssapi_build_ctx(Gssctxt **ctx); +void ssh_gssapi_delete_ctx(Gssctxt **ctx); +OM_uint32 ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID oid); + +/* In the server */ +int ssh_gssapi_userok(char *name); + +void ssh_gssapi_do_child(char ***envp, u_int *envsizep); +void ssh_gssapi_cleanup_creds(void *ignored); +void ssh_gssapi_storecreds(void); + +#endif /* GSSAPI */ + +#endif /* _SSH_GSS_H */ diff --git a/ssh_config.5 b/ssh_config.5 index fb341d79..f99562b9 100644 --- a/ssh_config.5 +++ b/ssh_config.5 @@ -34,7 +34,7 @@ .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. .\" -.\" $OpenBSD: ssh_config.5,v 1.17 2003/08/13 08:46:31 markus Exp $ +.\" $OpenBSD: ssh_config.5,v 1.18 2003/08/22 10:56:09 markus Exp $ .Dd September 25, 1999 .Dt SSH_CONFIG 5 .Os @@ -331,6 +331,18 @@ The default is Specifies a file to use for the global host key database instead of .Pa /etc/ssh/ssh_known_hosts . +.It Cm GSSAPIAuthentication +Specifies whether authentication based on GSSAPI may be used, either using +the result of a successful key exchange, or using GSSAPI user +authentication. +The default is +.Dq yes . +Note that this option applies to protocol version 2 only. +.It Cm GSSAPIDelegateCredentials +Forward (delegate) credentials to the server. +The default is +.Dq no . +Note that this option applies to protocol version 2 only. .It Cm HostbasedAuthentication Specifies whether to try rhosts based authentication with public key authentication. diff --git a/sshconnect2.c b/sshconnect2.c index 6a0bd409..c71ad506 100644 --- a/sshconnect2.c +++ b/sshconnect2.c @@ -23,7 +23,7 @@ */ #include "includes.h" -RCSID("$OpenBSD: sshconnect2.c,v 1.120 2003/06/24 08:23:46 markus Exp $"); +RCSID("$OpenBSD: sshconnect2.c,v 1.121 2003/08/22 10:56:09 markus Exp $"); #ifdef KRB5 #include <krb5.h> @@ -57,6 +57,10 @@ RCSID("$OpenBSD: sshconnect2.c,v 1.120 2003/06/24 08:23:46 markus Exp $"); #include "msg.h" #include "pathnames.h" +#ifdef GSSAPI +#include "ssh-gss.h" +#endif + /* import */ extern char *client_version_string; extern char *server_version_string; @@ -178,6 +182,8 @@ struct Authctxt { Sensitive *sensitive; /* kbd-interactive */ int info_req_seen; + /* generic */ + void *methoddata; }; struct Authmethod { char *name; /* string to compare against server's list */ @@ -201,6 +207,15 @@ int userauth_kbdint(Authctxt *); int userauth_hostbased(Authctxt *); int userauth_kerberos(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 *); @@ -213,6 +228,12 @@ static Authmethod *authmethod_lookup(const char *name); static char *authmethods_get(void); Authmethod authmethods[] = { +#ifdef GSSAPI + {"gssapi", + userauth_gssapi, + &options.gss_authentication, + NULL}, +#endif {"hostbased", userauth_hostbased, &options.hostbased_authentication, @@ -283,6 +304,7 @@ ssh_userauth2(const char *local_user, const char *server_user, char *host, 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) @@ -306,6 +328,10 @@ ssh_userauth2(const char *local_user, const char *server_user, char *host, void userauth(Authctxt *authctxt, char *authlist) { + if (authctxt->methoddata) { + xfree(authctxt->methoddata); + authctxt->methoddata = NULL; + } if (authlist == NULL) { authlist = authctxt->authlist; } else { @@ -361,6 +387,8 @@ input_userauth_success(int type, u_int32_t seq, void *ctxt) fatal("input_userauth_success: no authentication context"); if (authctxt->authlist) xfree(authctxt->authlist); + if (authctxt->methoddata) + xfree(authctxt->methoddata); authctxt->success = 1; /* break out */ } @@ -449,6 +477,228 @@ done: userauth(authctxt, NULL); } +#ifdef GSSAPI +int +userauth_gssapi(Authctxt *authctxt) +{ + Gssctxt *gssctxt = NULL; + static gss_OID_set supported = NULL; + static int mech = 0; + OM_uint32 min; + int ok = 0; + + /* Try one GSSAPI method at a time, rather than sending them all at + * once. */ + + if (supported == NULL) + gss_indicate_mechs(&min, &supported); + + /* Check to see if the mechanism is usable before we offer it */ + while (mech<supported->count && !ok) { + if (gssctxt) + ssh_gssapi_delete_ctx(&gssctxt); + ssh_gssapi_build_ctx(&gssctxt); + ssh_gssapi_set_oid(gssctxt, &supported->elements[mech]); + + /* My DER encoding requires length<128 */ + if (supported->elements[mech].length < 128 && + !GSS_ERROR(ssh_gssapi_import_name(gssctxt, + 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); + + /* Some servers encode the OID incorrectly (as we used to) */ + if (datafellows & SSH_BUG_GSSAPI_BER) { + packet_put_string(supported->elements[mech].elements, + supported->elements[mech].length); + } else { + packet_put_int((supported->elements[mech].length)+2); + packet_put_char(SSH_GSS_OIDTYPE); + packet_put_char(supported->elements[mech].length); + packet_put_raw(supported->elements[mech].elements, + supported->elements[mech].length); + } + + packet_send(); + + dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response); + dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token); + dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error); + dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok); + + mech++; /* Move along to next candidate */ + + return 1; +} + +void +input_gssapi_response(int type, u_int32_t plen, void *ctxt) +{ + Authctxt *authctxt = ctxt; + Gssctxt *gssctxt; + OM_uint32 status, ms; + int oidlen; + char *oidv; + gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; + + if (authctxt == NULL) + fatal("input_gssapi_response: no authentication context"); + gssctxt = authctxt->methoddata; + + /* Setup our OID */ + oidv = packet_get_string(&oidlen); + + if (datafellows & SSH_BUG_GSSAPI_BER) { + if (!ssh_gssapi_check_oid(gssctxt, oidv, oidlen)) + fatal("Server returned different OID than expected"); + } else { + if(oidv[0] != SSH_GSS_OIDTYPE || oidv[1] != oidlen-2) { + debug("Badly encoded mechanism OID received"); + userauth(authctxt, NULL); + xfree(oidv); + return; + } + if (!ssh_gssapi_check_oid(gssctxt, oidv+2, oidlen-2)) + fatal("Server returned different OID than expected"); + } + + packet_check_eom(); + + xfree(oidv); + + status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds, + GSS_C_NO_BUFFER, &send_tok, NULL); + if (GSS_ERROR(status)) { + if (send_tok.length > 0) { + packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK); + packet_put_string(send_tok.value, send_tok.length); + packet_send(); + gss_release_buffer(&ms, &send_tok); + } + /* Start again with next method on list */ + debug("Trying to start again"); + userauth(authctxt, NULL); + return; + } + + /* We must have data to send */ + packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN); + packet_put_string(send_tok.value, send_tok.length); + packet_send(); + gss_release_buffer(&ms, &send_tok); +} + +void +input_gssapi_token(int type, u_int32_t plen, void *ctxt) +{ + Authctxt *authctxt = ctxt; + Gssctxt *gssctxt; + gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; + gss_buffer_desc recv_tok; + OM_uint32 status, ms; + u_int slen; + + if (authctxt == NULL) + fatal("input_gssapi_response: no authentication context"); + gssctxt = authctxt->methoddata; + + recv_tok.value = packet_get_string(&slen); + recv_tok.length = slen; /* safe typecast */ + + packet_check_eom(); + + status=ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds, + &recv_tok, &send_tok, NULL); + + xfree(recv_tok.value); + + if (GSS_ERROR(status)) { + if (send_tok.length > 0) { + packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK); + packet_put_string(send_tok.value, send_tok.length); + packet_send(); + gss_release_buffer(&ms, &send_tok); + } + /* Start again with the next method in the list */ + userauth(authctxt, NULL); + return; + } + + if (send_tok.length > 0) { + packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN); + packet_put_string(send_tok.value, send_tok.length); + packet_send(); + gss_release_buffer(&ms, &send_tok); + } + + if (status == GSS_S_COMPLETE) { + /* If that succeeded, send a exchange complete message */ + packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE); + packet_send(); + } +} + +void +input_gssapi_errtok(int type, u_int32_t plen, void *ctxt) +{ + Authctxt *authctxt = ctxt; + Gssctxt *gssctxt; + gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; + gss_buffer_desc recv_tok; + OM_uint32 status, ms; + + if (authctxt == NULL) + fatal("input_gssapi_response: no authentication context"); + gssctxt = authctxt->methoddata; + + recv_tok.value = packet_get_string(&recv_tok.length); + + packet_check_eom(); + + /* Stick it into GSSAPI and see what it says */ + status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds, + &recv_tok, &send_tok, NULL); + + xfree(recv_tok.value); + gss_release_buffer(&ms, &send_tok); + + /* Server will be returning a failed packet after this one */ +} + +void +input_gssapi_error(int type, u_int32_t plen, void *ctxt) +{ + OM_uint32 maj, min; + char *msg; + char *lang; + + maj=packet_get_int(); + min=packet_get_int(); + msg=packet_get_string(NULL); + lang=packet_get_string(NULL); + + packet_check_eom(); + + debug("Server GSSAPI Error:\n%s\n", msg); + xfree(msg); + xfree(lang); +} +#endif /* GSSAPI */ + int userauth_none(Authctxt *authctxt) { diff --git a/sshd_config b/sshd_config index a2bd2ff6..29453909 100644 --- a/sshd_config +++ b/sshd_config @@ -1,4 +1,4 @@ -# $OpenBSD: sshd_config,v 1.63 2003/08/13 08:46:31 markus Exp $ +# $OpenBSD: sshd_config,v 1.64 2003/08/22 10:56:09 markus Exp $ # This is the sshd server system-wide configuration file. See # sshd_config(5) for more information. @@ -63,6 +63,10 @@ #KerberosTicketCleanup yes #KerberosTgtPassing no +# GSSAPI options +#GSSAPIAuthentication no +#GSSAPICleanupCreds yes + # Set this to 'yes' to enable PAM authentication (via challenge-response) # and session processing. Depending on your PAM configuration, this may # bypass the setting of 'PasswordAuthentication' diff --git a/sshd_config.5 b/sshd_config.5 index 3d920cc8..8857c673 100644 --- a/sshd_config.5 +++ b/sshd_config.5 @@ -34,7 +34,7 @@ .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. .\" -.\" $OpenBSD: sshd_config.5,v 1.22 2003/08/13 08:46:31 markus Exp $ +.\" $OpenBSD: sshd_config.5,v 1.23 2003/08/22 10:56:09 markus Exp $ .Dd September 25, 1999 .Dt SSHD_CONFIG 5 .Os @@ -225,6 +225,19 @@ or .Dq no . The default is .Dq no . +.It Cm GSSAPIAuthentication +Specifies whether authentication based on GSSAPI may be used, either using +the result of a successful key exchange, or using GSSAPI user +authentication. +The default is +.Dq no . +Note that this option applies to protocol version 2 only. +.It Cm GSSAPICleanupCredentials +Specifies whether to automatically destroy the user's credentials cache +on logout. +The default is +.Dq yes . +Note that this option applies to protocol version 2 only. .It Cm HostbasedAuthentication Specifies whether rhosts or /etc/hosts.equiv authentication together with successful public key client host authentication is allowed |