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 |