File openssh-7.2p2-gssapi_key_exchange.patch of Package openssh.37539
From f9f4d77e1045b02c4447c4a1ec6bbd97c0ad2dc1 Mon Sep 17 00:00:00 2001
From: Old openssh patches <pcerny@suse.com>
Date: Wed, 26 Oct 2022 09:50:50 +0200
Subject: [PATCH] openssh-7.2p2-gssapi_key_exchange
# HG changeset patch
# Parent fa4660c63ee2629912b5901936fc4236671fc264
GSSAPI Key Exchange implementation
---
ChangeLog.gssapi | 113 ++++++++++++
Makefile.in | 4 +-
auth-krb5.c | 14 +-
auth.c | 1 +
auth2-gss.c | 48 ++++-
auth2.c | 2 +
clientloop.c | 15 +-
configure.ac | 24 +++
gss-genr.c | 278 ++++++++++++++++++++++++++++-
gss-serv-krb5.c | 86 ++++++++-
gss-serv.c | 181 +++++++++++++++++--
kex.c | 19 ++
kex.h | 14 ++
kexgssc.c | 364 ++++++++++++++++++++++++++++++++++++++
kexgsss.c | 311 ++++++++++++++++++++++++++++++++
monitor.c | 108 ++++++++++-
monitor.h | 3 +
monitor_wrap.c | 47 ++++-
monitor_wrap.h | 4 +-
readconf.c | 43 +++++
readconf.h | 5 +
regress/cert-hostkey.sh | 3 +-
regress/cert-userkey.sh | 2 +-
regress/hostkey-agent.sh | 2 +
regress/hostkey-rotate.sh | 2 +
regress/kextype.sh | 3 +
regress/keygen-change.sh | 1 +
servconf.c | 28 +++
servconf.h | 4 +
ssh-gss.h | 39 +++-
ssh_config | 2 +
ssh_config.0 | 31 ++++
ssh_config.5 | 32 ++++
sshconnect2.c | 128 +++++++++++++-
sshd.c | 164 +++++++++++++++++
sshd_config | 2 +
sshd_config.0 | 12 ++
sshd_config.5 | 11 ++
sshkey.c | 2 +
sshkey.h | 1 +
40 files changed, 2109 insertions(+), 44 deletions(-)
create mode 100644 ChangeLog.gssapi
create mode 100644 kexgssc.c
create mode 100644 kexgsss.c
diff --git a/ChangeLog.gssapi b/ChangeLog.gssapi
new file mode 100644
index 00000000..f117a336
--- /dev/null
+++ b/ChangeLog.gssapi
@@ -0,0 +1,113 @@
+20110101
+ - Finally update for OpenSSH 5.6p1
+ - Add GSSAPIServerIdentity option from Jim Basney
+
+20100308
+ - [ Makefile.in, key.c, key.h ]
+ Updates for OpenSSH 5.4p1
+ - [ servconf.c ]
+ Include GSSAPI options in the sshd -T configuration dump, and flag
+ some older configuration options as being unsupported. Thanks to Colin
+ Watson.
+ -
+
+20100124
+ - [ sshconnect2.c ]
+ Adapt to deal with additional element in Authmethod structure. Thanks to
+ Colin Watson
+
+20090615
+ - [ gss-genr.c gss-serv.c kexgssc.c kexgsss.c monitor.c sshconnect2.c
+ sshd.c ]
+ Fix issues identified by Greg Hudson following a code review
+ Check return value of gss_indicate_mechs
+ Protect GSSAPI calls in monitor, so they can only be used if enabled
+ Check return values of bignum functions in key exchange
+ Use BN_clear_free to clear other side's DH value
+ Make ssh_gssapi_id_kex more robust
+ Only configure kex table pointers if GSSAPI is enabled
+ Don't leak mechanism list, or gss mechanism list
+ Cast data.length before printing
+ If serverkey isn't provided, use an empty string, rather than NULL
+
+20090201
+ - [ gss-genr.c gss-serv.c kex.h kexgssc.c readconf.c readconf.h ssh-gss.h
+ ssh_config.5 sshconnet2.c ]
+ Add support for the GSSAPIClientIdentity option, which allows the user
+ to specify which GSSAPI identity to use to contact a given server
+
+20080404
+ - [ gss-serv.c ]
+ Add code to actually implement GSSAPIStrictAcceptCheck, which had somehow
+ been omitted from a previous version of this patch. Reported by Borislav
+ Stoichkov
+
+20070317
+ - [ gss-serv-krb5.c ]
+ Remove C99ism, where new_ccname was being declared in the middle of a
+ function
+
+20061220
+ - [ servconf.c ]
+ Make default for GSSAPIStrictAcceptorCheck be Yes, to match previous, and
+ documented, behaviour. Reported by Dan Watson.
+
+20060910
+ - [ gss-genr.c kexgssc.c kexgsss.c kex.h monitor.c sshconnect2.c sshd.c
+ ssh-gss.h ]
+ add support for gss-group14-sha1 key exchange mechanisms
+ - [ gss-serv.c servconf.c servconf.h sshd_config sshd_config.5 ]
+ Add GSSAPIStrictAcceptorCheck option to allow the disabling of
+ acceptor principal checking on multi-homed machines.
+ <Bugzilla #928>
+ - [ sshd_config ssh_config ]
+ Add settings for GSSAPIKeyExchange and GSSAPITrustDNS to the sample
+ configuration files
+ - [ kexgss.c kegsss.c sshconnect2.c sshd.c ]
+ Code cleanup. Replace strlen/xmalloc/snprintf sequences with xasprintf()
+ Limit length of error messages displayed by client
+
+20060909
+ - [ gss-genr.c gss-serv.c ]
+ move ssh_gssapi_acquire_cred() and ssh_gssapi_server_ctx to be server
+ only, where they belong
+ <Bugzilla #1225>
+
+20060829
+ - [ gss-serv-krb5.c ]
+ Fix CCAPI credentials cache name when creating KRB5CCNAME environment
+ variable
+
+20060828
+ - [ gss-genr.c ]
+ Avoid Heimdal context freeing problem
+ <Fixed upstream 20060829>
+
+20060818
+ - [ gss-genr.c ssh-gss.h sshconnect2.c ]
+ Make sure that SPENGO is disabled
+ <Bugzilla #1218 - Fixed upstream 20060818>
+
+20060421
+ - [ gssgenr.c, sshconnect2.c ]
+ a few type changes (signed versus unsigned, int versus size_t) to
+ fix compiler errors/warnings
+ (from jbasney AT ncsa.uiuc.edu)
+ - [ kexgssc.c, sshconnect2.c ]
+ fix uninitialized variable warnings
+ (from jbasney AT ncsa.uiuc.edu)
+ - [ gssgenr.c ]
+ pass oid to gss_display_status (helpful when using GSSAPI mechglue)
+ (from jbasney AT ncsa.uiuc.edu)
+ <Bugzilla #1220 >
+ - [ gss-serv-krb5.c ]
+ #ifdef HAVE_GSSAPI_KRB5 should be #ifdef HAVE_GSSAPI_KRB5_H
+ (from jbasney AT ncsa.uiuc.edu)
+ <Fixed upstream 20060304>
+ - [ readconf.c, readconf.h, ssh_config.5, sshconnect2.c
+ add client-side GssapiKeyExchange option
+ (from jbasney AT ncsa.uiuc.edu)
+ - [ sshconnect2.c ]
+ add support for GssapiTrustDns option for gssapi-with-mic
+ (from jbasney AT ncsa.uiuc.edu)
+ <gssapi-with-mic support is Bugzilla #1008>
diff --git a/Makefile.in b/Makefile.in
index 4ac19507..391f8483 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -94,8 +94,8 @@ LIBSSH_OBJS=${LIBOPENSSH_OBJS} \
ssh-ed25519.o digest-openssl.o digest-libc.o hmac.o \
sc25519.o ge25519.o fe25519.o ed25519.o verify.o hash.o blocks.o \
kex.o kexdh.o kexgex.o kexecdh.o kexc25519.o \
- kexdhc.o kexgexc.o kexecdhc.o kexc25519c.o \
- kexdhs.o kexgexs.o kexecdhs.o kexc25519s.o \
+ kexdhc.o kexgexc.o kexecdhc.o kexc25519c.o kexgssc.o \
+ kexdhs.o kexgexs.o kexecdhs.o kexc25519s.o kexgsss.o \
platform-pledge.o
LIBSSH_OBJS += fips.o
diff --git a/auth-krb5.c b/auth-krb5.c
index d1c5a2f3..42265dce 100644
--- a/auth-krb5.c
+++ b/auth-krb5.c
@@ -183,8 +183,13 @@ auth_krb5_password(Authctxt *authctxt, const char *password)
len = strlen(authctxt->krb5_ticket_file) + 6;
authctxt->krb5_ccname = xmalloc(len);
+#ifdef USE_CCAPI
+ snprintf(authctxt->krb5_ccname, len, "API:%s",
+ authctxt->krb5_ticket_file);
+#else
snprintf(authctxt->krb5_ccname, len, "FILE:%s",
authctxt->krb5_ticket_file);
+#endif
#ifdef USE_PAM
if (options.use_pam)
@@ -244,12 +249,18 @@ ssh_krb5_cc_gen(krb5_context ctx, krb5_ccache *ccache) {
int tmpfd, ret, oerrno;
char ccname[40];
mode_t old_umask;
+#ifdef USE_CCAPI
+ char cctemplate[] = "API:krb5cc_%d";
+#else
+ char cctemplate[] = "FILE:/tmp/krb5cc_%d_XXXXXXXXXX";
+#endif
ret = snprintf(ccname, sizeof(ccname),
- "FILE:/tmp/krb5cc_%d_XXXXXXXXXX", geteuid());
+ cctemplate, geteuid());
if (ret < 0 || (size_t)ret >= sizeof(ccname))
return ENOMEM;
+#ifndef USE_CCAPI
old_umask = umask(0177);
tmpfd = mkstemp(ccname + strlen("FILE:"));
oerrno = errno;
@@ -266,6 +277,7 @@ ssh_krb5_cc_gen(krb5_context ctx, krb5_ccache *ccache) {
return oerrno;
}
close(tmpfd);
+#endif
return (krb5_cc_resolve(ctx, ccname, ccache));
}
diff --git a/auth.c b/auth.c
index 407f8ece..752c04c7 100644
--- a/auth.c
+++ b/auth.c
@@ -354,6 +354,7 @@ auth_root_allowed(const char *method)
case PERMIT_NO_PASSWD:
if (strcmp(method, "publickey") == 0 ||
strcmp(method, "hostbased") == 0 ||
+ strcmp(method, "gssapi-keyex") == 0 ||
strcmp(method, "gssapi-with-mic") == 0)
return 1;
break;
diff --git a/auth2-gss.c b/auth2-gss.c
index 1ca83577..3b5036df 100644
--- a/auth2-gss.c
+++ b/auth2-gss.c
@@ -1,7 +1,7 @@
/* $OpenBSD: auth2-gss.c,v 1.22 2015/01/19 20:07:45 markus Exp $ */
/*
- * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
+ * Copyright (c) 2001-2007 Simon Wilkinson. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
@@ -53,6 +53,40 @@ static int input_gssapi_mic(int type, u_int32_t plen, void *ctxt);
static int input_gssapi_exchange_complete(int type, u_int32_t plen, void *ctxt);
static int input_gssapi_errtok(int, u_int32_t, void *);
+/*
+ * The 'gssapi_keyex' userauth mechanism.
+ */
+static int
+userauth_gsskeyex(Authctxt *authctxt)
+{
+ int authenticated = 0;
+ Buffer b;
+ gss_buffer_desc mic, gssbuf;
+ u_int len;
+
+ mic.value = packet_get_string(&len);
+ mic.length = len;
+
+ packet_check_eom();
+
+ ssh_gssapi_buildmic(&b, authctxt->user, authctxt->service,
+ "gssapi-keyex");
+
+ gssbuf.value = buffer_ptr(&b);
+ gssbuf.length = buffer_len(&b);
+
+ /* gss_kex_context is NULL with privsep, so we can't check it here */
+ if (!GSS_ERROR(PRIVSEP(ssh_gssapi_checkmic(gss_kex_context,
+ &gssbuf, &mic))))
+ authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user,
+ authctxt->pw));
+
+ buffer_free(&b);
+ free(mic.value);
+
+ return (authenticated);
+}
+
/*
* We only support those mechanisms that we know about (ie ones that we know
* how to check local user kuserok and the like)
@@ -238,7 +272,8 @@ input_gssapi_exchange_complete(int type, u_int32_t plen, void *ctxt)
packet_check_eom();
- authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user));
+ authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user,
+ authctxt->pw));
authctxt->postponed = 0;
dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
@@ -274,7 +309,8 @@ input_gssapi_mic(int type, u_int32_t plen, void *ctxt)
gssbuf.length = buffer_len(&b);
if (!GSS_ERROR(PRIVSEP(ssh_gssapi_checkmic(gssctxt, &gssbuf, &mic))))
- authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user));
+ authenticated =
+ PRIVSEP(ssh_gssapi_userok(authctxt->user, authctxt->pw));
else
logit("GSSAPI MIC check failed");
@@ -290,6 +326,12 @@ input_gssapi_mic(int type, u_int32_t plen, void *ctxt)
return 0;
}
+Authmethod method_gsskeyex = {
+ "gssapi-keyex",
+ userauth_gsskeyex,
+ &options.gss_authentication
+};
+
Authmethod method_gssapi = {
"gssapi-with-mic",
userauth_gssapi,
diff --git a/auth2.c b/auth2.c
index 71779622..3f49bdca 100644
--- a/auth2.c
+++ b/auth2.c
@@ -70,6 +70,7 @@ extern Authmethod method_passwd;
extern Authmethod method_kbdint;
extern Authmethod method_hostbased;
#ifdef GSSAPI
+extern Authmethod method_gsskeyex;
extern Authmethod method_gssapi;
#endif
@@ -77,6 +78,7 @@ Authmethod *authmethods[] = {
&method_none,
&method_pubkey,
#ifdef GSSAPI
+ &method_gsskeyex,
&method_gssapi,
#endif
&method_passwd,
diff --git a/clientloop.c b/clientloop.c
index 9820455c..b1953538 100644
--- a/clientloop.c
+++ b/clientloop.c
@@ -114,6 +114,10 @@
#include "ssherr.h"
#include "hostfile.h"
+#ifdef GSSAPI
+#include "ssh-gss.h"
+#endif
+
/* import options */
extern Options options;
@@ -1662,9 +1666,18 @@ client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
break;
/* Do channel operations unless rekeying in progress. */
- if (!ssh_packet_is_rekeying(active_state))
+ if (!ssh_packet_is_rekeying(active_state)) {
channel_after_select(readset, writeset);
+#ifdef GSSAPI
+ if (options.gss_renewal_rekey &&
+ ssh_gssapi_credentials_updated((Gssctxt *)NULL)) {
+ debug("credentials updated - forcing rekey");
+ need_rekeying = 1;
+ }
+#endif
+ }
+
/* Buffer input from the connection. */
client_process_net_input(readset);
diff --git a/configure.ac b/configure.ac
index eb589758..c9b63f9c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -632,6 +632,30 @@ main() { if (NSVersionOfRunTimeLibrary("System") >= (60 << 16))
[Use tunnel device compatibility to OpenBSD])
AC_DEFINE([SSH_TUN_PREPEND_AF], [1],
[Prepend the address family to IP tunnel traffic])
+ AC_MSG_CHECKING(if we have the Security Authorization Session API)
+ AC_TRY_COMPILE([#include <Security/AuthSession.h>],
+ [SessionCreate(0, 0);],
+ [ac_cv_use_security_session_api="yes"
+ AC_DEFINE(USE_SECURITY_SESSION_API, 1,
+ [platform has the Security Authorization Session API])
+ LIBS="$LIBS -framework Security"
+ AC_MSG_RESULT(yes)],
+ [ac_cv_use_security_session_api="no"
+ AC_MSG_RESULT(no)])
+ AC_MSG_CHECKING(if we have an in-memory credentials cache)
+ AC_TRY_COMPILE(
+ [#include <Kerberos/Kerberos.h>],
+ [cc_context_t c;
+ (void) cc_initialize (&c, 0, NULL, NULL);],
+ [AC_DEFINE(USE_CCAPI, 1,
+ [platform uses an in-memory credentials cache])
+ LIBS="$LIBS -framework Security"
+ AC_MSG_RESULT(yes)
+ if test "x$ac_cv_use_security_session_api" = "xno"; then
+ AC_MSG_ERROR(*** Need a security framework to use the credentials cache API ***)
+ fi],
+ [AC_MSG_RESULT(no)]
+ )
m4_pattern_allow([AU_IPv])
AC_CHECK_DECL([AU_IPv4], [],
AC_DEFINE([AU_IPv4], [0], [System only supports IPv4 audit records])
diff --git a/gss-genr.c b/gss-genr.c
index d617d600..e2d1ccbe 100644
--- a/gss-genr.c
+++ b/gss-genr.c
@@ -1,7 +1,7 @@
/* $OpenBSD: gss-genr.c,v 1.23 2015/01/20 23:14:00 deraadt Exp $ */
/*
- * Copyright (c) 2001-2007 Simon Wilkinson. All rights reserved.
+ * Copyright (c) 2001-2009 Simon Wilkinson. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
@@ -41,12 +41,167 @@
#include "buffer.h"
#include "log.h"
#include "ssh2.h"
+#include "cipher.h"
+#include "key.h"
+#include "kex.h"
+#include <openssl/evp.h>
#include "ssh-gss.h"
extern u_char *session_id2;
extern u_int session_id2_len;
+typedef struct {
+ char *encoded;
+ gss_OID oid;
+} ssh_gss_kex_mapping;
+
+/*
+ * XXX - It would be nice to find a more elegant way of handling the
+ * XXX passing of the key exchange context to the userauth routines
+ */
+
+Gssctxt *gss_kex_context = NULL;
+
+static ssh_gss_kex_mapping *gss_enc2oid = NULL;
+
+int
+ssh_gssapi_oid_table_ok() {
+ return (gss_enc2oid != NULL);
+}
+
+/*
+ * Return a list of the gss-group1-sha1 mechanisms supported by this program
+ *
+ * We test mechanisms to ensure that we can use them, to avoid starting
+ * a key exchange with a bad mechanism
+ */
+
+char *
+ssh_gssapi_client_mechanisms(const char *host, const char *client) {
+ gss_OID_set gss_supported;
+ OM_uint32 min_status;
+
+ if (GSS_ERROR(gss_indicate_mechs(&min_status, &gss_supported)))
+ return NULL;
+
+ return(ssh_gssapi_kex_mechs(gss_supported, ssh_gssapi_check_mechanism,
+ host, client));
+}
+
+char *
+ssh_gssapi_kex_mechs(gss_OID_set gss_supported, ssh_gssapi_check_fn *check,
+ const char *host, const char *client) {
+ Buffer buf;
+ size_t i;
+ int oidpos, enclen;
+ char *mechs, *encoded;
+ u_char digest[EVP_MAX_MD_SIZE];
+ char deroid[2];
+ const EVP_MD *evp_md = EVP_md5();
+ EVP_MD_CTX md;
+
+ if (gss_enc2oid != NULL) {
+ for (i = 0; gss_enc2oid[i].encoded != NULL; i++)
+ free(gss_enc2oid[i].encoded);
+ free(gss_enc2oid);
+ }
+
+ gss_enc2oid = xmalloc(sizeof(ssh_gss_kex_mapping) *
+ (gss_supported->count + 1));
+
+ buffer_init(&buf);
+
+ oidpos = 0;
+ for (i = 0; i < gss_supported->count; i++) {
+ if (gss_supported->elements[i].length < 128 &&
+ (*check)(NULL, &(gss_supported->elements[i]), host, client)) {
+
+ deroid[0] = SSH_GSS_OIDTYPE;
+ deroid[1] = gss_supported->elements[i].length;
+
+ EVP_DigestInit(&md, evp_md);
+ EVP_DigestUpdate(&md, deroid, 2);
+ EVP_DigestUpdate(&md,
+ gss_supported->elements[i].elements,
+ gss_supported->elements[i].length);
+ EVP_DigestFinal(&md, digest, NULL);
+
+ encoded = xmalloc(EVP_MD_size(evp_md) * 2);
+ enclen = __b64_ntop(digest, EVP_MD_size(evp_md),
+ encoded, EVP_MD_size(evp_md) * 2);
+
+ if (oidpos != 0)
+ buffer_put_char(&buf, ',');
+
+ buffer_append(&buf, KEX_GSS_GEX_SHA1_ID,
+ sizeof(KEX_GSS_GEX_SHA1_ID) - 1);
+ buffer_append(&buf, encoded, enclen);
+ buffer_put_char(&buf, ',');
+ buffer_append(&buf, KEX_GSS_GRP1_SHA1_ID,
+ sizeof(KEX_GSS_GRP1_SHA1_ID) - 1);
+ buffer_append(&buf, encoded, enclen);
+ buffer_put_char(&buf, ',');
+ buffer_append(&buf, KEX_GSS_GRP14_SHA1_ID,
+ sizeof(KEX_GSS_GRP14_SHA1_ID) - 1);
+ buffer_append(&buf, encoded, enclen);
+
+ gss_enc2oid[oidpos].oid = &(gss_supported->elements[i]);
+ gss_enc2oid[oidpos].encoded = encoded;
+ oidpos++;
+ }
+ }
+ gss_enc2oid[oidpos].oid = NULL;
+ gss_enc2oid[oidpos].encoded = NULL;
+
+ buffer_put_char(&buf, '\0');
+
+ mechs = xmalloc(buffer_len(&buf));
+ buffer_get(&buf, mechs, buffer_len(&buf));
+ buffer_free(&buf);
+
+ if (strlen(mechs) == 0) {
+ free(mechs);
+ mechs = NULL;
+ }
+
+ return (mechs);
+}
+
+gss_OID
+ssh_gssapi_id_kex(Gssctxt *ctx, char *name, int kex_type) {
+ int i = 0;
+
+ switch (kex_type) {
+ case KEX_GSS_GRP1_SHA1:
+ if (strlen(name) < sizeof(KEX_GSS_GRP1_SHA1_ID))
+ return GSS_C_NO_OID;
+ name += sizeof(KEX_GSS_GRP1_SHA1_ID) - 1;
+ break;
+ case KEX_GSS_GRP14_SHA1:
+ if (strlen(name) < sizeof(KEX_GSS_GRP14_SHA1_ID))
+ return GSS_C_NO_OID;
+ name += sizeof(KEX_GSS_GRP14_SHA1_ID) - 1;
+ break;
+ case KEX_GSS_GEX_SHA1:
+ if (strlen(name) < sizeof(KEX_GSS_GEX_SHA1_ID))
+ return GSS_C_NO_OID;
+ name += sizeof(KEX_GSS_GEX_SHA1_ID) - 1;
+ break;
+ default:
+ return GSS_C_NO_OID;
+ }
+
+ while (gss_enc2oid[i].encoded != NULL &&
+ strcmp(name, gss_enc2oid[i].encoded) != 0)
+ i++;
+
+ if (gss_enc2oid[i].oid != NULL && ctx != NULL)
+ ssh_gssapi_set_oid(ctx, gss_enc2oid[i].oid);
+
+ return gss_enc2oid[i].oid;
+}
+
/* 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)
@@ -199,7 +354,7 @@ ssh_gssapi_init_ctx(Gssctxt *ctx, int deleg_creds, gss_buffer_desc *recv_tok,
}
ctx->major = gss_init_sec_context(&ctx->minor,
- GSS_C_NO_CREDENTIAL, &ctx->context, ctx->name, ctx->oid,
+ ctx->client_creds, &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);
@@ -228,9 +383,43 @@ ssh_gssapi_import_name(Gssctxt *ctx, const char *host)
return (ctx->major);
}
+OM_uint32
+ssh_gssapi_client_identity(Gssctxt *ctx, const char *name)
+{
+ gss_buffer_desc gssbuf;
+ gss_name_t gssname;
+ OM_uint32 status;
+ gss_OID_set oidset;
+
+ gssbuf.value = (void *) name;
+ gssbuf.length = strlen(gssbuf.value);
+
+ gss_create_empty_oid_set(&status, &oidset);
+ gss_add_oid_set_member(&status, ctx->oid, &oidset);
+
+ ctx->major = gss_import_name(&ctx->minor, &gssbuf,
+ GSS_C_NT_USER_NAME, &gssname);
+
+ if (!ctx->major)
+ ctx->major = gss_acquire_cred(&ctx->minor,
+ gssname, 0, oidset, GSS_C_INITIATE,
+ &ctx->client_creds, NULL, NULL);
+
+ gss_release_name(&status, &gssname);
+ gss_release_oid_set(&status, &oidset);
+
+ if (ctx->major)
+ ssh_gssapi_error(ctx);
+
+ return(ctx->major);
+}
+
OM_uint32
ssh_gssapi_sign(Gssctxt *ctx, gss_buffer_t buffer, gss_buffer_t hash)
{
+ if (ctx == NULL)
+ return -1;
+
if ((ctx->major = gss_get_mic(&ctx->minor, ctx->context,
GSS_C_QOP_DEFAULT, buffer, hash)))
ssh_gssapi_error(ctx);
@@ -238,6 +427,19 @@ ssh_gssapi_sign(Gssctxt *ctx, gss_buffer_t buffer, gss_buffer_t hash)
return (ctx->major);
}
+/* Priviledged when used by server */
+OM_uint32
+ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic)
+{
+ if (ctx == NULL)
+ return -1;
+
+ ctx->major = gss_verify_mic(&ctx->minor, ctx->context,
+ gssbuf, gssmic, NULL);
+
+ return (ctx->major);
+}
+
void
ssh_gssapi_buildmic(Buffer *b, const char *user, const char *service,
const char *context)
@@ -251,11 +453,16 @@ ssh_gssapi_buildmic(Buffer *b, const char *user, const char *service,
}
int
-ssh_gssapi_check_mechanism(Gssctxt **ctx, gss_OID oid, const char *host)
+ssh_gssapi_check_mechanism(Gssctxt **ctx, gss_OID oid, const char *host,
+ const char *client)
{
gss_buffer_desc token = GSS_C_EMPTY_BUFFER;
OM_uint32 major, minor;
gss_OID_desc spnego_oid = {6, (void *)"\x2B\x06\x01\x05\x05\x02"};
+ Gssctxt *intctx = NULL;
+
+ if (ctx == NULL)
+ ctx = &intctx;
/* RFC 4462 says we MUST NOT do SPNEGO */
if (oid->length == spnego_oid.length &&
@@ -265,6 +472,10 @@ ssh_gssapi_check_mechanism(Gssctxt **ctx, gss_OID oid, const char *host)
ssh_gssapi_build_ctx(ctx);
ssh_gssapi_set_oid(*ctx, oid);
major = ssh_gssapi_import_name(*ctx, host);
+
+ if (!GSS_ERROR(major) && client)
+ major = ssh_gssapi_client_identity(*ctx, client);
+
if (!GSS_ERROR(major)) {
major = ssh_gssapi_init_ctx(*ctx, 0, GSS_C_NO_BUFFER, &token,
NULL);
@@ -274,10 +485,69 @@ ssh_gssapi_check_mechanism(Gssctxt **ctx, gss_OID oid, const char *host)
GSS_C_NO_BUFFER);
}
- if (GSS_ERROR(major))
+ if (GSS_ERROR(major) || intctx != NULL)
ssh_gssapi_delete_ctx(ctx);
return (!GSS_ERROR(major));
}
+int
+ssh_gssapi_credentials_updated(Gssctxt *ctxt) {
+ static gss_name_t saved_name = GSS_C_NO_NAME;
+ static OM_uint32 saved_lifetime = 0;
+ static gss_OID saved_mech = GSS_C_NO_OID;
+ static gss_name_t name;
+ static OM_uint32 last_call = 0;
+ OM_uint32 lifetime, now, major, minor;
+ int equal;
+ /* TODO: recheck
+ gss_cred_usage_t usage = GSS_C_INITIATE;
+ */
+
+ now = time(NULL);
+
+ if (ctxt) {
+ debug("Rekey has happened - updating saved versions");
+
+ if (saved_name != GSS_C_NO_NAME)
+ gss_release_name(&minor, &saved_name);
+
+ major = gss_inquire_cred(&minor, GSS_C_NO_CREDENTIAL,
+ &saved_name, &saved_lifetime, NULL, NULL);
+
+ if (!GSS_ERROR(major)) {
+ saved_mech = ctxt->oid;
+ saved_lifetime+= now;
+ } else {
+ /* Handle the error */
+ }
+ return 0;
+ }
+
+ if (now - last_call < 10)
+ return 0;
+
+ last_call = now;
+
+ if (saved_mech == GSS_C_NO_OID)
+ return 0;
+
+ major = gss_inquire_cred(&minor, GSS_C_NO_CREDENTIAL,
+ &name, &lifetime, NULL, NULL);
+ if (major == GSS_S_CREDENTIALS_EXPIRED)
+ return 0;
+ else if (GSS_ERROR(major))
+ return 0;
+
+ major = gss_compare_name(&minor, saved_name, name, &equal);
+ gss_release_name(&minor, &name);
+ if (GSS_ERROR(major))
+ return 0;
+
+ if (equal && (saved_lifetime < lifetime + now - 10))
+ return 1;
+
+ return 0;
+}
+
#endif /* GSSAPI */
diff --git a/gss-serv-krb5.c b/gss-serv-krb5.c
index 795992d9..f94140b2 100644
--- a/gss-serv-krb5.c
+++ b/gss-serv-krb5.c
@@ -1,7 +1,7 @@
/* $OpenBSD: gss-serv-krb5.c,v 1.8 2013/07/20 01:55:13 djm Exp $ */
/*
- * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
+ * Copyright (c) 2001-2007 Simon Wilkinson. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
@@ -121,8 +121,11 @@ ssh_gssapi_krb5_storecreds(ssh_gssapi_client *client)
krb5_error_code problem;
krb5_principal princ;
OM_uint32 maj_status, min_status;
+ /* TODO:
int len;
+ */
const char *errmsg;
+ const char *new_ccname;
if (client->creds == NULL) {
debug("No credentials stored");
@@ -181,11 +184,16 @@ ssh_gssapi_krb5_storecreds(ssh_gssapi_client *client)
return;
}
- client->store.filename = xstrdup(krb5_cc_get_name(krb_context, ccache));
+ new_ccname = krb5_cc_get_name(krb_context, ccache);
+
client->store.envvar = "KRB5CCNAME";
- len = strlen(client->store.filename) + 6;
- client->store.envval = xmalloc(len);
- snprintf(client->store.envval, len, "FILE:%s", client->store.filename);
+#ifdef USE_CCAPI
+ xasprintf(&client->store.envval, "API:%s", new_ccname);
+ client->store.filename = NULL;
+#else
+ xasprintf(&client->store.envval, "FILE:%s", new_ccname);
+ client->store.filename = xstrdup(new_ccname);
+#endif
#ifdef USE_PAM
if (options.use_pam)
@@ -197,6 +205,71 @@ ssh_gssapi_krb5_storecreds(ssh_gssapi_client *client)
return;
}
+int
+ssh_gssapi_krb5_updatecreds(ssh_gssapi_ccache *store,
+ ssh_gssapi_client *client)
+{
+ krb5_ccache ccache = NULL;
+ krb5_principal principal = NULL;
+ char *name = NULL;
+ krb5_error_code problem;
+ OM_uint32 maj_status, min_status;
+
+ if ((problem = krb5_cc_resolve(krb_context, store->envval, &ccache))) {
+ logit("krb5_cc_resolve(): %.100s",
+ krb5_get_err_text(krb_context, problem));
+ return 0;
+ }
+
+ /* Find out who the principal in this cache is */
+ if ((problem = krb5_cc_get_principal(krb_context, ccache,
+ &principal))) {
+ logit("krb5_cc_get_principal(): %.100s",
+ krb5_get_err_text(krb_context, problem));
+ krb5_cc_close(krb_context, ccache);
+ return 0;
+ }
+
+ if ((problem = krb5_unparse_name(krb_context, principal, &name))) {
+ logit("krb5_unparse_name(): %.100s",
+ krb5_get_err_text(krb_context, problem));
+ krb5_free_principal(krb_context, principal);
+ krb5_cc_close(krb_context, ccache);
+ return 0;
+ }
+
+
+ if (strcmp(name,client->exportedname.value)!=0) {
+ debug("Name in local credentials cache differs. Not storing");
+ krb5_free_principal(krb_context, principal);
+ krb5_cc_close(krb_context, ccache);
+ krb5_free_unparsed_name(krb_context, name);
+ return 0;
+ }
+ krb5_free_unparsed_name(krb_context, name);
+
+ /* Name matches, so lets get on with it! */
+
+ if ((problem = krb5_cc_initialize(krb_context, ccache, principal))) {
+ logit("krb5_cc_initialize(): %.100s",
+ krb5_get_err_text(krb_context, problem));
+ krb5_free_principal(krb_context, principal);
+ krb5_cc_close(krb_context, ccache);
+ return 0;
+ }
+
+ krb5_free_principal(krb_context, principal);
+
+ if ((maj_status = gss_krb5_copy_ccache(&min_status, client->creds,
+ ccache))) {
+ logit("gss_krb5_copy_ccache() failed. Sorry!");
+ krb5_cc_close(krb_context, ccache);
+ return 0;
+ }
+
+ return 1;
+}
+
ssh_gssapi_mech gssapi_kerberos_mech = {
"toWM5Slw5Ew8Mqkay+al2g==",
"Kerberos",
@@ -204,7 +277,8 @@ ssh_gssapi_mech gssapi_kerberos_mech = {
NULL,
&ssh_gssapi_krb5_userok,
NULL,
- &ssh_gssapi_krb5_storecreds
+ &ssh_gssapi_krb5_storecreds,
+ &ssh_gssapi_krb5_updatecreds
};
#endif /* KRB5 */
diff --git a/gss-serv.c b/gss-serv.c
index 53993d67..ff3e83c2 100644
--- a/gss-serv.c
+++ b/gss-serv.c
@@ -1,7 +1,7 @@
/* $OpenBSD: gss-serv.c,v 1.29 2015/05/22 03:50:02 djm Exp $ */
/*
- * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
+ * Copyright (c) 2001-2009 Simon Wilkinson. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
@@ -45,17 +45,19 @@
#include "session.h"
#include "misc.h"
#include "servconf.h"
+#include "uidswap.h"
#include "ssh-gss.h"
+#include "monitor_wrap.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, NULL}};
+ GSS_C_NO_CREDENTIAL, GSS_C_NO_NAME, NULL, {NULL, NULL, NULL, NULL, NULL}, 0, 0};
ssh_gssapi_mech gssapi_null_mech =
- { NULL, NULL, {0, NULL}, NULL, NULL, NULL, NULL};
+ { NULL, NULL, {0, NULL}, NULL, NULL, NULL, NULL, NULL};
#ifdef KRB5
extern ssh_gssapi_mech gssapi_kerberos_mech;
@@ -141,6 +143,29 @@ ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID oid)
return (ssh_gssapi_acquire_cred(*ctx));
}
+/* Unprivileged */
+char *
+ssh_gssapi_server_mechanisms() {
+ gss_OID_set supported;
+
+ ssh_gssapi_supported_oids(&supported);
+ return (ssh_gssapi_kex_mechs(supported, &ssh_gssapi_server_check_mech,
+ NULL, NULL));
+}
+
+/* Unprivileged */
+int
+ssh_gssapi_server_check_mech(Gssctxt **dum, gss_OID oid, const char *data,
+ const char *dummy) {
+ Gssctxt *ctx = NULL;
+ int res;
+
+ res = !GSS_ERROR(PRIVSEP(ssh_gssapi_server_ctx(&ctx, oid)));
+ ssh_gssapi_delete_ctx(&ctx);
+
+ return (res);
+}
+
/* Unprivileged */
void
ssh_gssapi_supported_oids(gss_OID_set *oidset)
@@ -151,7 +176,9 @@ ssh_gssapi_supported_oids(gss_OID_set *oidset)
gss_OID_set supported;
gss_create_empty_oid_set(&min_status, oidset);
- gss_indicate_mechs(&min_status, &supported);
+
+ if (GSS_ERROR(gss_indicate_mechs(&min_status, &supported)))
+ return;
while (supported_mechs[i]->name != NULL) {
if (GSS_ERROR(gss_test_oid_set_member(&min_status,
@@ -277,8 +304,48 @@ OM_uint32
ssh_gssapi_getclient(Gssctxt *ctx, ssh_gssapi_client *client)
{
int i = 0;
+ int equal = 0;
+ gss_name_t new_name = GSS_C_NO_NAME;
+ gss_buffer_desc ename = GSS_C_EMPTY_BUFFER;
+
+ if (options.gss_store_rekey && client->used && ctx->client_creds) {
+ if (client->mech->oid.length != ctx->oid->length ||
+ (memcmp(client->mech->oid.elements,
+ ctx->oid->elements, ctx->oid->length) !=0)) {
+ debug("Rekeyed credentials have different mechanism");
+ return GSS_S_COMPLETE;
+ }
+
+ if ((ctx->major = gss_inquire_cred_by_mech(&ctx->minor,
+ ctx->client_creds, ctx->oid, &new_name,
+ NULL, NULL, NULL))) {
+ ssh_gssapi_error(ctx);
+ return (ctx->major);
+ }
- gss_buffer_desc ename;
+ ctx->major = gss_compare_name(&ctx->minor, client->name,
+ new_name, &equal);
+
+ if (GSS_ERROR(ctx->major)) {
+ ssh_gssapi_error(ctx);
+ return (ctx->major);
+ }
+
+ if (!equal) {
+ debug("Rekeyed credentials have different name");
+ return GSS_S_COMPLETE;
+ }
+
+ debug("Marking rekeyed credentials for export");
+
+ gss_release_name(&ctx->minor, &client->name);
+ gss_release_cred(&ctx->minor, &client->creds);
+ client->name = new_name;
+ client->creds = ctx->client_creds;
+ ctx->client_creds = GSS_C_NO_CREDENTIAL;
+ client->updated = 1;
+ return GSS_S_COMPLETE;
+ }
client->mech = NULL;
@@ -293,6 +360,13 @@ ssh_gssapi_getclient(Gssctxt *ctx, ssh_gssapi_client *client)
if (client->mech == NULL)
return GSS_S_FAILURE;
+ if (ctx->client_creds &&
+ (ctx->major = gss_inquire_cred_by_mech(&ctx->minor,
+ ctx->client_creds, ctx->oid, &client->name, NULL, NULL, NULL))) {
+ ssh_gssapi_error(ctx);
+ return (ctx->major);
+ }
+
if ((ctx->major = gss_display_name(&ctx->minor, ctx->client,
&client->displayname, NULL))) {
ssh_gssapi_error(ctx);
@@ -310,6 +384,8 @@ ssh_gssapi_getclient(Gssctxt *ctx, ssh_gssapi_client *client)
return (ctx->major);
}
+ gss_release_buffer(&ctx->minor, &ename);
+
/* 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;
@@ -357,7 +433,7 @@ ssh_gssapi_do_child(char ***envp, u_int *envsizep)
/* Privileged */
int
-ssh_gssapi_userok(char *user)
+ssh_gssapi_userok(char *user, struct passwd *pw)
{
OM_uint32 lmin;
@@ -367,9 +443,11 @@ ssh_gssapi_userok(char *user)
return 0;
}
if (gssapi_client.mech && gssapi_client.mech->userok)
- if ((*gssapi_client.mech->userok)(&gssapi_client, user))
+ if ((*gssapi_client.mech->userok)(&gssapi_client, user)) {
+ gssapi_client.used = 1;
+ gssapi_client.store.owner = pw;
return 1;
- else {
+ } else {
/* Destroy delegated credentials if userok fails */
gss_release_buffer(&lmin, &gssapi_client.displayname);
gss_release_buffer(&lmin, &gssapi_client.exportedname);
@@ -384,13 +462,90 @@ ssh_gssapi_userok(char *user)
}
/* Privileged */
-OM_uint32
-ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic)
+/* These bits are only used for rekeying. The unpriviledged child is running
+ * as the user, the monitor is root.
+ *
+ * In the child, we want to :
+ * *) Ask the monitor to store our credentials into the store we specify
+ * *) If it succeeds, maybe do a PAM update
+ */
+
+/* Stuff for PAM */
+
+#ifdef USE_PAM
+static int ssh_gssapi_simple_conv(int n, const struct pam_message **msg,
+ struct pam_response **resp, void *data)
{
- ctx->major = gss_verify_mic(&ctx->minor, ctx->context,
- gssbuf, gssmic, NULL);
+ return (PAM_CONV_ERR);
+}
+#endif
- return (ctx->major);
+void
+ssh_gssapi_rekey_creds() {
+ int ok;
+ int ret;
+#ifdef USE_PAM
+ pam_handle_t *pamh = NULL;
+ struct pam_conv pamconv = {ssh_gssapi_simple_conv, NULL};
+ char *envstr;
+#endif
+
+ if (gssapi_client.store.filename == NULL &&
+ gssapi_client.store.envval == NULL &&
+ gssapi_client.store.envvar == NULL)
+ return;
+
+ ok = PRIVSEP(ssh_gssapi_update_creds(&gssapi_client.store));
+
+ if (!ok)
+ return;
+
+ debug("Rekeyed credentials stored successfully");
+
+ /* Actually managing to play with the ssh pam stack from here will
+ * be next to impossible. In any case, we may want different options
+ * for rekeying. So, use our own :)
+ */
+#ifdef USE_PAM
+ if (!use_privsep) {
+ debug("Not even going to try and do PAM with privsep disabled");
+ return;
+ }
+
+ ret = pam_start("sshd-rekey", gssapi_client.store.owner->pw_name,
+ &pamconv, &pamh);
+ if (ret)
+ return;
+
+ xasprintf(&envstr, "%s=%s", gssapi_client.store.envvar,
+ gssapi_client.store.envval);
+
+ ret = pam_putenv(pamh, envstr);
+ if (!ret)
+ pam_setcred(pamh, PAM_REINITIALIZE_CRED);
+ pam_end(pamh, PAM_SUCCESS);
+#endif
+}
+
+int
+ssh_gssapi_update_creds(ssh_gssapi_ccache *store) {
+ int ok = 0;
+
+ /* Check we've got credentials to store */
+ if (!gssapi_client.updated)
+ return 0;
+
+ gssapi_client.updated = 0;
+
+ temporarily_use_uid(gssapi_client.store.owner);
+ if (gssapi_client.mech && gssapi_client.mech->updatecreds)
+ ok = (*gssapi_client.mech->updatecreds)(store, &gssapi_client);
+ else
+ debug("No update function for this mechanism");
+
+ restore_uid();
+
+ return ok;
}
#endif
diff --git a/kex.c b/kex.c
index 1d6425be..afd6dc24 100644
--- a/kex.c
+++ b/kex.c
@@ -56,6 +56,10 @@
#include "fips.h"
+#ifdef GSSAPI
+#include "ssh-gss.h"
+#endif
+
#if OPENSSL_VERSION_NUMBER >= 0x00907000L
# if defined(HAVE_EVP_SHA256)
# define evp_ssh_sha256 EVP_sha256
@@ -109,6 +113,11 @@ static const struct kexalg kexalgs_all[] = {
#if defined(HAVE_EVP_SHA256) || !defined(WITH_OPENSSL)
{ KEX_CURVE25519_SHA256, KEX_C25519_SHA256, 0, SSH_DIGEST_SHA256 },
#endif /* HAVE_EVP_SHA256 || !WITH_OPENSSL */
+#ifdef GSSAPI
+ { KEX_GSS_GEX_SHA1_ID, KEX_GSS_GEX_SHA1, 0, SSH_DIGEST_SHA1 },
+ { KEX_GSS_GRP1_SHA1_ID, KEX_GSS_GRP1_SHA1, 0, SSH_DIGEST_SHA1 },
+ { KEX_GSS_GRP14_SHA1_ID, KEX_GSS_GRP14_SHA1, 0, SSH_DIGEST_SHA1 },
+#endif
{ NULL, -1, -1, -1},
};
@@ -130,6 +139,10 @@ static const struct kexalg kexalgs_fips140_2[] = {
# endif /* OPENSSL_HAS_NISTP521 */
#endif /* OPENSSL_HAS_ECC */
#endif /* WITH_OPENSSL */
+#ifdef GSSAPI
+ { KEX_GSS_GEX_SHA1_ID, KEX_GSS_GEX_SHA1, 0, SSH_DIGEST_SHA1 },
+ { KEX_GSS_GRP14_SHA1_ID, KEX_GSS_GRP14_SHA1, 0, SSH_DIGEST_SHA1 },
+#endif
{ NULL, -1, -1, -1},
};
@@ -180,6 +193,12 @@ kex_alg_by_name(const char *name)
for (k = fips_select_kexalgs(); k->name != NULL; k++) {
if (strcmp(k->name, name) == 0)
return k;
+#ifdef GSSAPI
+ if (strncmp(name, "gss-", 4) == 0) {
+ if (strncmp(k->name, name, strlen(k->name)) == 0)
+ return k;
+ }
+#endif
}
return NULL;
}
diff --git a/kex.h b/kex.h
index 1c589660..bdd17e55 100644
--- a/kex.h
+++ b/kex.h
@@ -92,6 +92,9 @@ enum kex_exchange {
KEX_DH_GEX_SHA256,
KEX_ECDH_SHA2,
KEX_C25519_SHA256,
+ KEX_GSS_GRP1_SHA1,
+ KEX_GSS_GRP14_SHA1,
+ KEX_GSS_GEX_SHA1,
KEX_MAX
};
@@ -140,6 +143,12 @@ struct kex {
u_int flags;
int hash_alg;
int ec_nid;
+#ifdef GSSAPI
+ int gss_deleg_creds;
+ int gss_trust_dns;
+ char *gss_host;
+ char *gss_client;
+#endif
char *client_version_string;
char *server_version_string;
char *failed_choice;
@@ -189,6 +198,11 @@ int kexecdh_client(struct ssh *);
int kexecdh_server(struct ssh *);
int kexc25519_client(struct ssh *);
int kexc25519_server(struct ssh *);
+
+#ifdef GSSAPI
+int kexgss_client(struct ssh *);
+int kexgss_server(struct ssh *);
+#endif
int kex_dh_hash(const char *, const char *,
const u_char *, size_t, const u_char *, size_t, const u_char *, size_t,
diff --git a/kexgssc.c b/kexgssc.c
new file mode 100644
index 00000000..559264dd
--- /dev/null
+++ b/kexgssc.c
@@ -0,0 +1,364 @@
+/*
+ * Copyright (c) 2001-2009 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 "includes.h"
+
+#include <openssl/crypto.h>
+#include <openssl/bn.h>
+
+#include <string.h>
+
+#include "xmalloc.h"
+#include "buffer.h"
+#include "ssh2.h"
+#include "key.h"
+#include "cipher.h"
+#include "digest.h"
+#include "kex.h"
+#include "log.h"
+#include "packet.h"
+#include "dh.h"
+
+#include "ssh-gss.h"
+
+#include "fips.h"
+
+int
+kexgss_client(struct ssh *ssh)
+{
+ struct kex *kex = ssh->kex;
+ gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
+ gss_buffer_desc recv_tok, gssbuf, msg_tok, *token_ptr;
+ Gssctxt *ctxt;
+ OM_uint32 maj_status, min_status, ret_flags;
+ u_int klen, kout, slen = 0, strlen;
+ size_t hashlen;
+ BIGNUM *dh_server_pub = NULL;
+ BIGNUM *shared_secret = NULL;
+ BIGNUM *p = NULL;
+ BIGNUM *g = NULL;
+ u_char *kbuf;
+ u_char hash[SSH_DIGEST_MAX_LENGTH];
+ u_char *serverhostkey = NULL;
+ u_char *empty = "";
+ char *msg;
+ /* TODO:
+ char *lang;
+ */
+ int type = 0;
+ int first = 1;
+ int nbits = 0, min = fips_dh_grp_min(), max = DH_GRP_MAX;
+ int p_bitlen;
+ int r;
+
+ /* Initialise our GSSAPI world */
+ ssh_gssapi_build_ctx(&ctxt);
+ if (ssh_gssapi_id_kex(ctxt, kex->name, kex->kex_type)
+ == GSS_C_NO_OID)
+ fatal("Couldn't identify host exchange");
+
+ if (ssh_gssapi_import_name(ctxt, kex->gss_host))
+ fatal("Couldn't import hostname");
+
+ if (kex->gss_client &&
+ ssh_gssapi_client_identity(ctxt, kex->gss_client))
+ fatal("Couldn't acquire client credentials");
+
+ switch (kex->kex_type) {
+ case KEX_GSS_GRP1_SHA1:
+ kex->dh = dh_new_group1();
+ break;
+ case KEX_GSS_GRP14_SHA1:
+ kex->dh = dh_new_group14();
+ break;
+ case KEX_GSS_GEX_SHA1:
+ debug("Doing group exchange\n");
+ nbits = dh_estimate(kex->we_need * 8);
+ packet_start(SSH2_MSG_KEXGSS_GROUPREQ);
+ packet_put_int(min);
+ packet_put_int(nbits);
+ packet_put_int(max);
+
+ packet_send();
+
+ packet_read_expect(SSH2_MSG_KEXGSS_GROUP);
+
+ if ((p = BN_new()) == NULL)
+ fatal("BN_new() failed");
+ packet_get_bignum2(p);
+ p_bitlen = BN_num_bits(p);
+ if ((g = BN_new()) == NULL)
+ fatal("BN_new() failed");
+ packet_get_bignum2(g);
+ packet_check_eom();
+
+ if (p_bitlen < min || p_bitlen > max) {
+ if (p_bitlen < min && p_bitlen >= DH_GRP_MIN_RFC)
+ logit("DH parameter offered by the server (%d bits) "
+ "is considered insecure. "
+ "You can lower the accepted minimum "
+ "via the KexDHMin option.",
+ p_bitlen);
+ fatal("GSSGRP_GEX group out of range: %d !< %d !< %d",
+ min, p_bitlen, max);
+ }
+
+ kex->dh = dh_new_group(g, p);
+ break;
+ default:
+ fatal("%s: Unexpected KEX type %d", __func__, kex->kex_type);
+ }
+
+ /* Step 1 - e is dh->pub_key */
+ dh_gen_key(kex->dh, kex->we_need * 8);
+
+ /* This is f, we initialise it now to make life easier */
+ dh_server_pub = BN_new();
+ if (dh_server_pub == NULL)
+ fatal("dh_server_pub == NULL");
+
+ token_ptr = GSS_C_NO_BUFFER;
+
+ do {
+ debug("Calling gss_init_sec_context");
+
+ maj_status = ssh_gssapi_init_ctx(ctxt,
+ kex->gss_deleg_creds, token_ptr, &send_tok,
+ &ret_flags);
+
+ if (GSS_ERROR(maj_status)) {
+ if (send_tok.length != 0) {
+ packet_start(SSH2_MSG_KEXGSS_CONTINUE);
+ packet_put_string(send_tok.value,
+ send_tok.length);
+ }
+ fatal("gss_init_context failed");
+ }
+
+ /* If we've got an old receive buffer get rid of it */
+ if (token_ptr != GSS_C_NO_BUFFER)
+ free(recv_tok.value);
+
+ if (maj_status == GSS_S_COMPLETE) {
+ /* If mutual state flag is not true, kex fails */
+ if (!(ret_flags & GSS_C_MUTUAL_FLAG))
+ fatal("Mutual authentication failed");
+
+ /* If integ avail flag is not true kex fails */
+ if (!(ret_flags & GSS_C_INTEG_FLAG))
+ fatal("Integrity check failed");
+ }
+
+ /*
+ * If we have data to send, then the last message that we
+ * received cannot have been a 'complete'.
+ */
+ if (send_tok.length != 0) {
+ if (first) {
+ packet_start(SSH2_MSG_KEXGSS_INIT);
+ packet_put_string(send_tok.value,
+ send_tok.length);
+ packet_put_bignum2(kex->dh->pub_key);
+ first = 0;
+ } else {
+ packet_start(SSH2_MSG_KEXGSS_CONTINUE);
+ packet_put_string(send_tok.value,
+ send_tok.length);
+ }
+ packet_send();
+ gss_release_buffer(&min_status, &send_tok);
+
+ /* If we've sent them data, they should reply */
+ do {
+ type = packet_read();
+ if (type == SSH2_MSG_KEXGSS_HOSTKEY) {
+ debug("Received KEXGSS_HOSTKEY");
+ if (serverhostkey)
+ fatal("Server host key received more than once");
+ serverhostkey =
+ packet_get_string(&slen);
+ }
+ } while (type == SSH2_MSG_KEXGSS_HOSTKEY);
+
+ switch (type) {
+ case SSH2_MSG_KEXGSS_CONTINUE:
+ debug("Received GSSAPI_CONTINUE");
+ if (maj_status == GSS_S_COMPLETE)
+ fatal("GSSAPI Continue received from server when complete");
+ recv_tok.value = packet_get_string(&strlen);
+ recv_tok.length = strlen;
+ break;
+ case SSH2_MSG_KEXGSS_COMPLETE:
+ debug("Received GSSAPI_COMPLETE");
+ packet_get_bignum2(dh_server_pub);
+ msg_tok.value = packet_get_string(&strlen);
+ msg_tok.length = strlen;
+
+ /* Is there a token included? */
+ if (packet_get_char()) {
+ recv_tok.value=
+ packet_get_string(&strlen);
+ recv_tok.length = strlen;
+ /* If we're already complete - protocol error */
+ if (maj_status == GSS_S_COMPLETE)
+ packet_disconnect("Protocol error: received token when complete");
+ } else {
+ /* No token included */
+ if (maj_status != GSS_S_COMPLETE)
+ packet_disconnect("Protocol error: did not receive final token");
+ }
+ break;
+ case SSH2_MSG_KEXGSS_ERROR:
+ debug("Received Error");
+ maj_status = packet_get_int();
+ min_status = packet_get_int();
+ msg = packet_get_string(NULL);
+ /* TODO:
+ lang = packet_get_string(NULL);
+ */
+ fatal("GSSAPI Error: \n%.400s",msg);
+ default:
+ packet_disconnect("Protocol error: didn't expect packet type %d",
+ type);
+ }
+ token_ptr = &recv_tok;
+ } else {
+ /* No data, and not complete */
+ if (maj_status != GSS_S_COMPLETE)
+ fatal("Not complete, and no token output");
+ }
+ } while (maj_status & GSS_S_CONTINUE_NEEDED);
+
+ /*
+ * We _must_ have received a COMPLETE message in reply from the
+ * server, which will have set dh_server_pub and msg_tok
+ */
+
+ if (type != SSH2_MSG_KEXGSS_COMPLETE)
+ fatal("Didn't receive a SSH2_MSG_KEXGSS_COMPLETE when I expected it");
+
+ /* Check f in range [1, p-1] */
+ if (!dh_pub_is_valid(kex->dh, dh_server_pub))
+ packet_disconnect("bad server public DH value");
+
+ /* compute K=f^x mod p */
+ klen = DH_size(kex->dh);
+ kbuf = xmalloc(klen);
+ kout = DH_compute_key(kbuf, dh_server_pub, kex->dh);
+ if (kout < 0)
+ fatal("DH_compute_key: failed");
+
+ shared_secret = BN_new();
+ if (shared_secret == NULL)
+ fatal("kexgss_client: BN_new failed");
+
+ if (BN_bin2bn(kbuf, kout, shared_secret) == NULL)
+ fatal("kexdh_client: BN_bin2bn failed");
+
+ explicit_bzero(kbuf, klen);
+ free(kbuf);
+ kbuf = NULL;
+
+ hashlen = sizeof(hash);
+
+ switch (kex->kex_type) {
+ case KEX_GSS_GRP1_SHA1:
+ case KEX_GSS_GRP14_SHA1:
+ kex_dh_hash( kex->client_version_string,
+ kex->server_version_string,
+ buffer_ptr(kex->my), buffer_len(kex->my),
+ buffer_ptr(kex->peer), buffer_len(kex->peer),
+ (serverhostkey ? serverhostkey : empty), slen,
+ kex->dh->pub_key, /* e */
+ dh_server_pub, /* f */
+ shared_secret, /* K */
+ hash, &hashlen
+ );
+ break;
+ case KEX_GSS_GEX_SHA1:
+ kexgex_hash(
+ kex->hash_alg,
+ kex->client_version_string,
+ kex->server_version_string,
+ buffer_ptr(kex->my), buffer_len(kex->my),
+ buffer_ptr(kex->peer), buffer_len(kex->peer),
+ (serverhostkey ? serverhostkey : empty), slen,
+ min, nbits, max,
+ kex->dh->p, kex->dh->g,
+ kex->dh->pub_key,
+ dh_server_pub,
+ shared_secret,
+ hash, &hashlen
+ );
+ break;
+ default:
+ fatal("%s: Unexpected KEX type %d", __func__, kex->kex_type);
+ }
+
+ BN_clear_free(dh_server_pub);
+
+ gssbuf.value = hash;
+ gssbuf.length = hashlen;
+
+ /* Verify that the hash matches the MIC we just got. */
+ if (GSS_ERROR(ssh_gssapi_checkmic(ctxt, &gssbuf, &msg_tok)))
+ packet_disconnect("Hash's MIC didn't verify");
+
+ free(msg_tok.value);
+
+ if (serverhostkey)
+ free(serverhostkey);
+
+ /* save session id */
+ if (kex->session_id == NULL) {
+ kex->session_id_len = hashlen;
+ kex->session_id = xmalloc(kex->session_id_len);
+ memcpy(kex->session_id, hash, kex->session_id_len);
+ }
+
+ if (kex->gss_deleg_creds)
+ ssh_gssapi_credentials_updated(ctxt);
+
+ if (gss_kex_context == NULL)
+ gss_kex_context = ctxt;
+ else
+ ssh_gssapi_delete_ctx(&ctxt);
+
+ if ((r = kex_derive_keys_bn(ssh, hash, hashlen, shared_secret)) == 0)
+ r = kex_send_newkeys(ssh);
+
+ explicit_bzero(hash, sizeof(hash));
+ DH_free(kex->dh);
+ kex->dh = NULL;
+ if (shared_secret)
+ BN_clear_free(shared_secret);
+ /* any errors should have finished as fatal */
+ return r;
+}
+
+#endif /* GSSAPI */
diff --git a/kexgsss.c b/kexgsss.c
new file mode 100644
index 00000000..ed5c5562
--- /dev/null
+++ b/kexgsss.c
@@ -0,0 +1,311 @@
+/*
+ * Copyright (c) 2001-2009 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 <string.h>
+
+#include <openssl/crypto.h>
+#include <openssl/bn.h>
+
+#include "xmalloc.h"
+#include "buffer.h"
+#include "ssh2.h"
+#include "key.h"
+#include "cipher.h"
+#include "digest.h"
+#include "kex.h"
+#include "log.h"
+#include "packet.h"
+#include "dh.h"
+#include "ssh-gss.h"
+#include "monitor_wrap.h"
+#include "servconf.h"
+
+#include "fips.h"
+
+extern ServerOptions options;
+
+void ssh_gssapi_rekey_creds();
+
+int
+kexgss_server(struct ssh *ssh)
+{
+ struct kex *kex = ssh->kex;
+ OM_uint32 maj_status, min_status;
+
+ /*
+ * Some GSSAPI implementations use the input value of ret_flags (an
+ * output variable) as a means of triggering mechanism specific
+ * features. Initializing it to zero avoids inadvertently
+ * activating this non-standard behaviour.
+ */
+
+ OM_uint32 ret_flags = 0;
+ gss_buffer_desc gssbuf, recv_tok, msg_tok;
+ gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
+ Gssctxt *ctxt = NULL;
+ u_int slen, klen, kout;
+ size_t hashlen;
+ u_char *kbuf;
+ u_char hash[SSH_DIGEST_MAX_LENGTH];
+ int min = -1, max = -1, nbits = -1;
+ BIGNUM *shared_secret = NULL;
+ BIGNUM *dh_client_pub = NULL;
+ int type = 0;
+ gss_OID oid;
+ char *mechs;
+ int r;
+
+ /* Initialise GSSAPI */
+
+ /* If we're rekeying, privsep means that some of the private structures
+ * in the GSSAPI code are no longer available. This kludges them back
+ * into life
+ */
+ if (!ssh_gssapi_oid_table_ok())
+ if ((mechs = ssh_gssapi_server_mechanisms()))
+ free(mechs);
+
+ debug2("%s: Identifying %s", __func__, kex->name);
+ oid = ssh_gssapi_id_kex(NULL, kex->name, kex->kex_type);
+ if (oid == GSS_C_NO_OID)
+ fatal("Unknown gssapi mechanism");
+
+ debug2("%s: Acquiring credentials", __func__);
+
+ if (GSS_ERROR(PRIVSEP(ssh_gssapi_server_ctx(&ctxt, oid))))
+ fatal("Unable to acquire credentials for the server");
+
+ switch (kex->kex_type) {
+ case KEX_GSS_GRP1_SHA1:
+ kex->dh = dh_new_group1();
+ break;
+ case KEX_GSS_GRP14_SHA1:
+ kex->dh = dh_new_group14();
+ break;
+ case KEX_GSS_GEX_SHA1:
+ debug("Doing group exchange");
+ packet_read_expect(SSH2_MSG_KEXGSS_GROUPREQ);
+ min = packet_get_int();
+ nbits = packet_get_int();
+ max = packet_get_int();
+ min = MAX(fips_dh_grp_min(), min);
+ max = MIN(DH_GRP_MAX, max);
+ packet_check_eom();
+ if (max < min || nbits < min || max < nbits) {
+ if (nbits < min && nbits >= DH_GRP_MIN_RFC)
+ logit("DH parameter requested by the client (%d bits) "
+ "is considered insecure. "
+ "You can lower the accepted minimum "
+ "via the KexDHMin option.",
+ nbits);
+ fatal("GSS_GEX, bad parameters: %d !< %d !< %d",
+ min, nbits, max);
+ }
+ kex->dh = PRIVSEP(choose_dh(min, nbits, max));
+ if (kex->dh == NULL)
+ packet_disconnect("Protocol error: no matching group found");
+
+ packet_start(SSH2_MSG_KEXGSS_GROUP);
+ packet_put_bignum2(kex->dh->p);
+ packet_put_bignum2(kex->dh->g);
+ packet_send();
+
+ packet_write_wait();
+ break;
+ default:
+ fatal("%s: Unexpected KEX type %d", __func__, kex->kex_type);
+ }
+
+ dh_gen_key(kex->dh, kex->we_need * 8);
+
+ do {
+ debug("Wait SSH2_MSG_GSSAPI_INIT");
+ type = packet_read();
+ switch(type) {
+ case SSH2_MSG_KEXGSS_INIT:
+ if (dh_client_pub != NULL)
+ fatal("Received KEXGSS_INIT after initialising");
+ recv_tok.value = packet_get_string(&slen);
+ recv_tok.length = slen;
+
+ if ((dh_client_pub = BN_new()) == NULL)
+ fatal("dh_client_pub == NULL");
+
+ packet_get_bignum2(dh_client_pub);
+
+ /* Send SSH_MSG_KEXGSS_HOSTKEY here, if we want */
+ break;
+ case SSH2_MSG_KEXGSS_CONTINUE:
+ recv_tok.value = packet_get_string(&slen);
+ recv_tok.length = slen;
+ break;
+ default:
+ packet_disconnect(
+ "Protocol error: didn't expect packet type %d",
+ type);
+ }
+
+ maj_status = PRIVSEP(ssh_gssapi_accept_ctx(ctxt, &recv_tok,
+ &send_tok, &ret_flags));
+
+ free(recv_tok.value);
+
+ if (maj_status != GSS_S_COMPLETE && send_tok.length == 0)
+ fatal("Zero length token output when incomplete");
+
+ if (dh_client_pub == NULL)
+ fatal("No client public key");
+
+ if (maj_status & GSS_S_CONTINUE_NEEDED) {
+ debug("Sending GSSAPI_CONTINUE");
+ packet_start(SSH2_MSG_KEXGSS_CONTINUE);
+ packet_put_string(send_tok.value, send_tok.length);
+ packet_send();
+ gss_release_buffer(&min_status, &send_tok);
+ }
+ } while (maj_status & GSS_S_CONTINUE_NEEDED);
+
+ if (GSS_ERROR(maj_status)) {
+ if (send_tok.length > 0) {
+ packet_start(SSH2_MSG_KEXGSS_CONTINUE);
+ packet_put_string(send_tok.value, send_tok.length);
+ packet_send();
+ }
+ fatal("accept_ctx died");
+ }
+
+ if (!(ret_flags & GSS_C_MUTUAL_FLAG))
+ fatal("Mutual Authentication flag wasn't set");
+
+ if (!(ret_flags & GSS_C_INTEG_FLAG))
+ fatal("Integrity flag wasn't set");
+
+ if (!dh_pub_is_valid(kex->dh, dh_client_pub))
+ packet_disconnect("bad client public DH value");
+
+ klen = DH_size(kex->dh);
+ kbuf = xmalloc(klen);
+ kout = DH_compute_key(kbuf, dh_client_pub, kex->dh);
+ if (kout < 0)
+ fatal("DH_compute_key: failed");
+
+ shared_secret = BN_new();
+ if (shared_secret == NULL)
+ fatal("kexgss_server: BN_new failed");
+
+ if (BN_bin2bn(kbuf, kout, shared_secret) == NULL)
+ fatal("kexgss_server: BN_bin2bn failed");
+
+ explicit_bzero(kbuf, klen);
+ free(kbuf);
+ kbuf = NULL;
+
+ hashlen = sizeof(hash);
+
+ switch (kex->kex_type) {
+ case KEX_GSS_GRP1_SHA1:
+ case KEX_GSS_GRP14_SHA1:
+ kex_dh_hash(
+ kex->client_version_string, kex->server_version_string,
+ buffer_ptr(kex->peer), buffer_len(kex->peer),
+ buffer_ptr(kex->my), buffer_len(kex->my),
+ NULL, 0, /* Change this if we start sending host keys */
+ dh_client_pub, kex->dh->pub_key, shared_secret,
+ hash, &hashlen
+ );
+ break;
+ case KEX_GSS_GEX_SHA1:
+ kexgex_hash(
+ kex->hash_alg,
+ kex->client_version_string, kex->server_version_string,
+ buffer_ptr(kex->peer), buffer_len(kex->peer),
+ buffer_ptr(kex->my), buffer_len(kex->my),
+ NULL, 0,
+ min, nbits, max,
+ kex->dh->p, kex->dh->g,
+ dh_client_pub,
+ kex->dh->pub_key,
+ shared_secret,
+ hash, &hashlen
+ );
+ break;
+ default:
+ fatal("%s: Unexpected KEX type %d", __func__, kex->kex_type);
+ }
+
+ BN_clear_free(dh_client_pub);
+
+ if (kex->session_id == NULL) {
+ kex->session_id_len = hashlen;
+ kex->session_id = xmalloc(kex->session_id_len);
+ memcpy(kex->session_id, hash, kex->session_id_len);
+ }
+
+ gssbuf.value = hash;
+ gssbuf.length = hashlen;
+
+ if (GSS_ERROR(PRIVSEP(ssh_gssapi_sign(ctxt,&gssbuf,&msg_tok))))
+ fatal("Couldn't get MIC");
+
+ packet_start(SSH2_MSG_KEXGSS_COMPLETE);
+ packet_put_bignum2(kex->dh->pub_key);
+ packet_put_string(msg_tok.value,msg_tok.length);
+
+ if (send_tok.length != 0) {
+ packet_put_char(1); /* true */
+ packet_put_string(send_tok.value, send_tok.length);
+ } else {
+ packet_put_char(0); /* false */
+ }
+ packet_send();
+
+ gss_release_buffer(&min_status, &send_tok);
+ gss_release_buffer(&min_status, &msg_tok);
+
+ if (gss_kex_context == NULL)
+ gss_kex_context = ctxt;
+ else
+ ssh_gssapi_delete_ctx(&ctxt);
+
+ if ((r = kex_derive_keys_bn(ssh, hash, hashlen, shared_secret)) == 0)
+ r = kex_send_newkeys(ssh);
+
+ explicit_bzero(hash, sizeof(hash));
+ DH_free(kex->dh);
+ kex->dh = NULL;
+ if (shared_secret)
+ BN_clear_free(shared_secret);
+
+ /* If this was a rekey, then save out any delegated credentials we
+ * just exchanged. */
+ if (options.gss_store_rekey)
+ ssh_gssapi_rekey_creds();
+
+ return r;
+}
+#endif /* GSSAPI */
diff --git a/monitor.c b/monitor.c
index ac7dd309..6c820232 100644
--- a/monitor.c
+++ b/monitor.c
@@ -156,6 +156,8 @@ int mm_answer_gss_setup_ctx(int, Buffer *);
int mm_answer_gss_accept_ctx(int, Buffer *);
int mm_answer_gss_userok(int, Buffer *);
int mm_answer_gss_checkmic(int, Buffer *);
+int mm_answer_gss_sign(int, Buffer *);
+int mm_answer_gss_updatecreds(int, Buffer *);
#endif
#ifdef SSH_AUDIT_EVENTS
@@ -233,11 +235,18 @@ struct mon_table mon_dispatch_proto20[] = {
{MONITOR_REQ_GSSSTEP, MON_ISAUTH, mm_answer_gss_accept_ctx},
{MONITOR_REQ_GSSUSEROK, MON_AUTH, mm_answer_gss_userok},
{MONITOR_REQ_GSSCHECKMIC, MON_ISAUTH, mm_answer_gss_checkmic},
+ {MONITOR_REQ_GSSSIGN, MON_ONCE, mm_answer_gss_sign},
#endif
{0, 0, NULL}
};
struct mon_table mon_dispatch_postauth20[] = {
+#ifdef GSSAPI
+ {MONITOR_REQ_GSSSETUP, 0, mm_answer_gss_setup_ctx},
+ {MONITOR_REQ_GSSSTEP, 0, mm_answer_gss_accept_ctx},
+ {MONITOR_REQ_GSSSIGN, 0, mm_answer_gss_sign},
+ {MONITOR_REQ_GSSUPCREDS, 0, mm_answer_gss_updatecreds},
+#endif
#ifdef WITH_OPENSSL
{MONITOR_REQ_MODULI, 0, mm_answer_moduli},
#endif
@@ -352,6 +361,10 @@ monitor_child_preauth(Authctxt *_authctxt, struct monitor *pmonitor)
/* Permit requests for moduli and signatures */
monitor_permit(mon_dispatch, MONITOR_REQ_MODULI, 1);
monitor_permit(mon_dispatch, MONITOR_REQ_SIGN, 1);
+#ifdef GSSAPI
+ /* and for the GSSAPI key exchange */
+ monitor_permit(mon_dispatch, MONITOR_REQ_GSSSETUP, 1);
+#endif
} else {
mon_dispatch = mon_dispatch_proto15;
@@ -460,6 +473,10 @@ 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);
+#ifdef GSSAPI
+ /* and for the GSSAPI key exchange */
+ monitor_permit(mon_dispatch, MONITOR_REQ_GSSSETUP, 1);
+#endif
} else {
mon_dispatch = mon_dispatch_postauth15;
monitor_permit(mon_dispatch, MONITOR_REQ_TERM, 1);
@@ -1861,6 +1878,13 @@ monitor_apply_keystate(struct monitor *pmonitor)
# endif
#endif /* WITH_OPENSSL */
kex->kex[KEX_C25519_SHA256] = kexc25519_server;
+#ifdef GSSAPI
+ if (options.gss_keyex) {
+ kex->kex[KEX_GSS_GRP1_SHA1] = kexgss_server;
+ kex->kex[KEX_GSS_GRP14_SHA1] = kexgss_server;
+ kex->kex[KEX_GSS_GEX_SHA1] = kexgss_server;
+ }
+#endif
kex->load_host_public_key=&get_hostkey_public_by_type;
kex->load_host_private_key=&get_hostkey_private_by_type;
kex->host_key_index=&get_hostkey_index;
@@ -1960,6 +1984,9 @@ mm_answer_gss_setup_ctx(int sock, Buffer *m)
OM_uint32 major;
u_int len;
+ if (!options.gss_authentication && !options.gss_keyex)
+ fatal("In GSSAPI monitor when GSSAPI is disabled");
+
goid.elements = buffer_get_string(m, &len);
goid.length = len;
@@ -1987,6 +2014,9 @@ mm_answer_gss_accept_ctx(int sock, Buffer *m)
OM_uint32 flags = 0; /* GSI needs this */
u_int len;
+ if (!options.gss_authentication && !options.gss_keyex)
+ fatal("In GSSAPI monitor when GSSAPI is disabled");
+
in.value = buffer_get_string(m, &len);
in.length = len;
major = ssh_gssapi_accept_ctx(gsscontext, &in, &out, &flags);
@@ -2004,6 +2034,7 @@ mm_answer_gss_accept_ctx(int sock, Buffer *m)
monitor_permit(mon_dispatch, MONITOR_REQ_GSSSTEP, 0);
monitor_permit(mon_dispatch, MONITOR_REQ_GSSUSEROK, 1);
monitor_permit(mon_dispatch, MONITOR_REQ_GSSCHECKMIC, 1);
+ monitor_permit(mon_dispatch, MONITOR_REQ_GSSSIGN, 1);
}
return (0);
}
@@ -2015,6 +2046,9 @@ mm_answer_gss_checkmic(int sock, Buffer *m)
OM_uint32 ret;
u_int len;
+ if (!options.gss_authentication && !options.gss_keyex)
+ fatal("In GSSAPI monitor when GSSAPI is disabled");
+
gssbuf.value = buffer_get_string(m, &len);
gssbuf.length = len;
mic.value = buffer_get_string(m, &len);
@@ -2041,7 +2075,11 @@ mm_answer_gss_userok(int sock, Buffer *m)
{
int authenticated;
- authenticated = authctxt->valid && ssh_gssapi_userok(authctxt->user);
+ if (!options.gss_authentication && !options.gss_keyex)
+ fatal("In GSSAPI monitor when GSSAPI is disabled");
+
+ authenticated = authctxt->valid &&
+ ssh_gssapi_userok(authctxt->user, authctxt->pw);
buffer_clear(m);
buffer_put_int(m, authenticated);
@@ -2054,5 +2092,73 @@ mm_answer_gss_userok(int sock, Buffer *m)
/* Monitor loop will terminate if authenticated */
return (authenticated);
}
+
+int
+mm_answer_gss_sign(int socket, Buffer *m)
+{
+ gss_buffer_desc data;
+ gss_buffer_desc hash = GSS_C_EMPTY_BUFFER;
+ OM_uint32 major, minor;
+ u_int len;
+
+ if (!options.gss_authentication && !options.gss_keyex)
+ fatal("In GSSAPI monitor when GSSAPI is disabled");
+
+ data.value = buffer_get_string(m, &len);
+ data.length = len;
+ if (data.length != 20)
+ fatal("%s: data length incorrect: %d", __func__,
+ (int) data.length);
+
+ /* Save the session ID on the first time around */
+ if (session_id2_len == 0) {
+ session_id2_len = data.length;
+ session_id2 = xmalloc(session_id2_len);
+ memcpy(session_id2, data.value, session_id2_len);
+ }
+ major = ssh_gssapi_sign(gsscontext, &data, &hash);
+
+ free(data.value);
+
+ buffer_clear(m);
+ buffer_put_int(m, major);
+ buffer_put_string(m, hash.value, hash.length);
+
+ mm_request_send(socket, MONITOR_ANS_GSSSIGN, m);
+
+ gss_release_buffer(&minor, &hash);
+
+ /* Turn on getpwnam permissions */
+ monitor_permit(mon_dispatch, MONITOR_REQ_PWNAM, 1);
+
+ /* And credential updating, for when rekeying */
+ monitor_permit(mon_dispatch, MONITOR_REQ_GSSUPCREDS, 1);
+
+ return (0);
+}
+
+int
+mm_answer_gss_updatecreds(int socket, Buffer *m) {
+ ssh_gssapi_ccache store;
+ int ok;
+
+ store.filename = buffer_get_string(m, NULL);
+ store.envvar = buffer_get_string(m, NULL);
+ store.envval = buffer_get_string(m, NULL);
+
+ ok = ssh_gssapi_update_creds(&store);
+
+ free(store.filename);
+ free(store.envvar);
+ free(store.envval);
+
+ buffer_clear(m);
+ buffer_put_int(m, ok);
+
+ mm_request_send(socket, MONITOR_ANS_GSSUPCREDS, m);
+
+ return(0);
+}
+
#endif /* GSSAPI */
diff --git a/monitor.h b/monitor.h
index 93b8b66d..9b204461 100644
--- a/monitor.h
+++ b/monitor.h
@@ -65,6 +65,9 @@ enum monitor_reqtype {
MONITOR_REQ_PAM_FREE_CTX = 110, MONITOR_ANS_PAM_FREE_CTX = 111,
MONITOR_REQ_AUDIT_EVENT = 112, MONITOR_REQ_AUDIT_COMMAND = 113,
+ MONITOR_REQ_GSSSIGN = 201, MONITOR_ANS_GSSSIGN = 202,
+ MONITOR_REQ_GSSUPCREDS = 203, MONITOR_ANS_GSSUPCREDS = 204,
+
};
struct mm_master;
diff --git a/monitor_wrap.c b/monitor_wrap.c
index c5db6df4..74fbd2ef 100644
--- a/monitor_wrap.c
+++ b/monitor_wrap.c
@@ -1068,7 +1068,7 @@ mm_ssh_gssapi_checkmic(Gssctxt *ctx, gss_buffer_t gssbuf, gss_buffer_t gssmic)
}
int
-mm_ssh_gssapi_userok(char *user)
+mm_ssh_gssapi_userok(char *user, struct passwd *pw)
{
Buffer m;
int authenticated = 0;
@@ -1085,5 +1085,50 @@ mm_ssh_gssapi_userok(char *user)
debug3("%s: user %sauthenticated",__func__, authenticated ? "" : "not ");
return (authenticated);
}
+
+OM_uint32
+mm_ssh_gssapi_sign(Gssctxt *ctx, gss_buffer_desc *data, gss_buffer_desc *hash)
+{
+ Buffer m;
+ OM_uint32 major;
+ u_int len;
+
+ buffer_init(&m);
+ buffer_put_string(&m, data->value, data->length);
+
+ mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSSIGN, &m);
+ mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSSIGN, &m);
+
+ major = buffer_get_int(&m);
+ hash->value = buffer_get_string(&m, &len);
+ hash->length = len;
+
+ buffer_free(&m);
+
+ return(major);
+}
+
+int
+mm_ssh_gssapi_update_creds(ssh_gssapi_ccache *store)
+{
+ Buffer m;
+ int ok;
+
+ buffer_init(&m);
+
+ buffer_put_cstring(&m, store->filename ? store->filename : "");
+ buffer_put_cstring(&m, store->envvar ? store->envvar : "");
+ buffer_put_cstring(&m, store->envval ? store->envval : "");
+
+ mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_GSSUPCREDS, &m);
+ mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_GSSUPCREDS, &m);
+
+ ok = buffer_get_int(&m);
+
+ buffer_free(&m);
+
+ return (ok);
+}
+
#endif /* GSSAPI */
diff --git a/monitor_wrap.h b/monitor_wrap.h
index eb820aee..403f8d00 100644
--- a/monitor_wrap.h
+++ b/monitor_wrap.h
@@ -58,8 +58,10 @@ BIGNUM *mm_auth_rsa_generate_challenge(Key *);
OM_uint32 mm_ssh_gssapi_server_ctx(Gssctxt **, gss_OID);
OM_uint32 mm_ssh_gssapi_accept_ctx(Gssctxt *,
gss_buffer_desc *, gss_buffer_desc *, OM_uint32 *);
-int mm_ssh_gssapi_userok(char *user);
+int mm_ssh_gssapi_userok(char *user, struct passwd *);
OM_uint32 mm_ssh_gssapi_checkmic(Gssctxt *, gss_buffer_t, gss_buffer_t);
+OM_uint32 mm_ssh_gssapi_sign(Gssctxt *, gss_buffer_t, gss_buffer_t);
+int mm_ssh_gssapi_update_creds(ssh_gssapi_ccache *);
#endif
#ifdef USE_PAM
diff --git a/readconf.c b/readconf.c
index 61eabf5f..d1a556b0 100644
--- a/readconf.c
+++ b/readconf.c
@@ -150,6 +150,8 @@ typedef enum {
oClearAllForwardings, oNoHostAuthenticationForLocalhost,
oEnableSSHKeysign, oRekeyLimit, oVerifyHostKeyDNS, oConnectTimeout,
oAddressFamily, oGssAuthentication, oGssDelegateCreds,
+ oGssTrustDns, oGssKeyEx, oGssClientIdentity, oGssRenewalRekey,
+ oGssServerIdentity,
oServerAliveInterval, oServerAliveCountMax, oIdentitiesOnly,
oSendEnv, oControlPath, oControlMaster, oControlPersist,
oHashKnownHosts,
@@ -196,10 +198,20 @@ static struct {
{ "afstokenpassing", oUnsupported },
#if defined(GSSAPI)
{ "gssapiauthentication", oGssAuthentication },
+ { "gssapikeyexchange", oGssKeyEx },
{ "gssapidelegatecredentials", oGssDelegateCreds },
+ { "gssapitrustdns", oGssTrustDns },
+ { "gssapiclientidentity", oGssClientIdentity },
+ { "gssapiserveridentity", oGssServerIdentity },
+ { "gssapirenewalforcesrekey", oGssRenewalRekey },
#else
{ "gssapiauthentication", oUnsupported },
+ { "gssapikeyexchange", oUnsupported },
{ "gssapidelegatecredentials", oUnsupported },
+ { "gssapitrustdns", oUnsupported },
+ { "gssapiclientidentity", oUnsupported },
+ { "gssapiserveridentity", oUnsupported },
+ { "gssapirenewalforcesrekey", oUnsupported },
#endif
{ "fallbacktorsh", oDeprecated },
{ "usersh", oDeprecated },
@@ -933,10 +945,30 @@ parse_time:
intptr = &options->gss_authentication;
goto parse_flag;
+ case oGssKeyEx:
+ intptr = &options->gss_keyex;
+ goto parse_flag;
+
case oGssDelegateCreds:
intptr = &options->gss_deleg_creds;
goto parse_flag;
+ case oGssTrustDns:
+ intptr = &options->gss_trust_dns;
+ goto parse_flag;
+
+ case oGssClientIdentity:
+ charptr = &options->gss_client_identity;
+ goto parse_string;
+
+ case oGssServerIdentity:
+ charptr = &options->gss_server_identity;
+ goto parse_string;
+
+ case oGssRenewalRekey:
+ intptr = &options->gss_renewal_rekey;
+ goto parse_flag;
+
case oBatchMode:
intptr = &options->batch_mode;
goto parse_flag;
@@ -1676,7 +1708,12 @@ initialize_options(Options * options)
options->pubkey_authentication = -1;
options->challenge_response_authentication = -1;
options->gss_authentication = -1;
+ options->gss_keyex = -1;
options->gss_deleg_creds = -1;
+ options->gss_trust_dns = -1;
+ options->gss_renewal_rekey = -1;
+ options->gss_client_identity = NULL;
+ options->gss_server_identity = NULL;
options->password_authentication = -1;
options->kbd_interactive_authentication = -1;
options->kbd_interactive_devices = NULL;
@@ -1806,8 +1843,14 @@ fill_default_options(Options * options)
options->challenge_response_authentication = 1;
if (options->gss_authentication == -1)
options->gss_authentication = 0;
+ if (options->gss_keyex == -1)
+ options->gss_keyex = 0;
if (options->gss_deleg_creds == -1)
options->gss_deleg_creds = 0;
+ if (options->gss_trust_dns == -1)
+ options->gss_trust_dns = 0;
+ if (options->gss_renewal_rekey == -1)
+ options->gss_renewal_rekey = 0;
if (options->password_authentication == -1)
options->password_authentication = 1;
if (options->kbd_interactive_authentication == -1)
diff --git a/readconf.h b/readconf.h
index ebe197b3..22c861fe 100644
--- a/readconf.h
+++ b/readconf.h
@@ -45,7 +45,12 @@ typedef struct {
int challenge_response_authentication;
/* Try S/Key or TIS, authentication. */
int gss_authentication; /* Try GSS authentication */
+ int gss_keyex; /* Try GSS key exchange */
int gss_deleg_creds; /* Delegate GSS credentials */
+ int gss_trust_dns; /* Trust DNS for GSS canonicalization */
+ int gss_renewal_rekey; /* Credential renewal forces rekey */
+ char *gss_client_identity; /* Principal to initiate GSSAPI with */
+ char *gss_server_identity; /* GSSAPI target principal */
int password_authentication; /* Try password
* authentication. */
int kbd_interactive_authentication; /* Try keyboard-interactive auth. */
diff --git a/regress/cert-hostkey.sh b/regress/cert-hostkey.sh
index 3f53922c..0b9267f0 100644
--- a/regress/cert-hostkey.sh
+++ b/regress/cert-hostkey.sh
@@ -9,6 +9,7 @@ rm -f $OBJ/cert_host_key* $OBJ/host_krl_*
# Allow all hostkey/pubkey types, prefer certs for the client
types=""
for i in `$SSH -Q key`; do
+ [ "$i" != null ] || continue
if [ -z "$types" ]; then
types="$i"
continue
@@ -46,7 +47,7 @@ touch $OBJ/host_revoked_plain
touch $OBJ/host_revoked_cert
cp $OBJ/host_ca_key.pub $OBJ/host_revoked_ca
-PLAIN_TYPES=`$SSH -Q key-plain | sed 's/^ssh-dss/ssh-dsa/g;s/^ssh-//'`
+PLAIN_TYPES=`$SSH -Q key-plain | sed 's/^ssh-dss/ssh-dsa/g;s/^ssh-//;/^null$/d'`
# Prepare certificate, plain key and CA KRLs
${SSHKEYGEN} -kf $OBJ/host_krl_empty || fatal "KRL init failed"
diff --git a/regress/cert-userkey.sh b/regress/cert-userkey.sh
index c38c00a0..4ad2617a 100644
--- a/regress/cert-userkey.sh
+++ b/regress/cert-userkey.sh
@@ -7,7 +7,7 @@ rm -f $OBJ/authorized_keys_$USER $OBJ/user_ca_key* $OBJ/cert_user_key*
cp $OBJ/sshd_proxy $OBJ/sshd_proxy_bak
cp $OBJ/ssh_proxy $OBJ/ssh_proxy_bak
-PLAIN_TYPES=`$SSH -Q key-plain | sed 's/^ssh-dss/ssh-dsa/;s/^ssh-//'`
+PLAIN_TYPES=`$SSH -Q key-plain | sed 's/^ssh-dss/ssh-dsa/g;s/^ssh-//;/^null$/d'`
kname() {
n=`echo "$1" | sed 's/^dsa/ssh-dss/;s/^rsa/ssh-rsa/;s/^ed/ssh-ed/'`
diff --git a/regress/hostkey-agent.sh b/regress/hostkey-agent.sh
index 094700da..4981e243 100644
--- a/regress/hostkey-agent.sh
+++ b/regress/hostkey-agent.sh
@@ -15,6 +15,7 @@ echo "HostKeyAgent $SSH_AUTH_SOCK" >> $OBJ/sshd_proxy.orig
trace "load hostkeys"
for k in `${SSH} -Q key-plain` ; do
+ [ "$k" != null ] || continue
${SSHKEYGEN} -qt $k -f $OBJ/agent-key.$k -N '' || fatal "ssh-keygen $k"
(
printf 'localhost-with-alias,127.0.0.1,::1 '
@@ -32,6 +33,7 @@ unset SSH_AUTH_SOCK
for ps in no yes; do
for k in `${SSH} -Q key-plain` ; do
+ [ "$k" != null ] || continue
verbose "key type $k privsep=$ps"
cp $OBJ/sshd_proxy.orig $OBJ/sshd_proxy
echo "UsePrivilegeSeparation $ps" >> $OBJ/sshd_proxy
diff --git a/regress/hostkey-rotate.sh b/regress/hostkey-rotate.sh
index d69de325..283bc62b 100644
--- a/regress/hostkey-rotate.sh
+++ b/regress/hostkey-rotate.sh
@@ -16,6 +16,7 @@ trace "prepare hostkeys"
nkeys=0
all_algs=""
for k in `${SSH} -Q key-plain` ; do
+ [ "$k" != null ] || continue
${SSHKEYGEN} -qt $k -f $OBJ/hkr.$k -N '' || fatal "ssh-keygen $k"
echo "Hostkey $OBJ/hkr.${k}" >> $OBJ/sshd_proxy.orig
nkeys=`expr $nkeys + 1`
@@ -63,6 +64,7 @@ check_key_present ssh-rsa || fail "didn't learn keys"
# Check each key type
for k in `${SSH} -Q key-plain` ; do
+ [ "$k" != null ] || continue
verbose "learn additional hostkeys, type=$k"
dossh -oStrictHostKeyChecking=yes -oHostKeyAlgorithms=$k,$all_algs
expect_nkeys $nkeys "learn hostkeys $k"
diff --git a/regress/kextype.sh b/regress/kextype.sh
index e2718990..426130d3 100644
--- a/regress/kextype.sh
+++ b/regress/kextype.sh
@@ -14,6 +14,9 @@ echo "KexAlgorithms=$KEXOPT" >> $OBJ/sshd_proxy
tries="1 2 3 4"
for k in `${SSH} -Q kex`; do
+ case $k in
+ gss-*) continue;;
+ esac
verbose "kex $k"
for i in $tries; do
${SSH} -F $OBJ/ssh_proxy -o KexAlgorithms=$k x true
diff --git a/regress/keygen-change.sh b/regress/keygen-change.sh
index e5618505..04166c69 100644
--- a/regress/keygen-change.sh
+++ b/regress/keygen-change.sh
@@ -12,6 +12,7 @@ if ssh_version 1; then
fi
for t in $KEYTYPES; do
+ [ "$t" != null ] || continue
# generate user key for agent
trace "generating $t key"
rm -f $OBJ/$t-key
diff --git a/servconf.c b/servconf.c
index d704b694..e3970dd1 100644
--- a/servconf.c
+++ b/servconf.c
@@ -123,8 +123,10 @@ initialize_server_options(ServerOptions *options)
options->kerberos_ticket_cleanup = -1;
options->kerberos_get_afs_token = -1;
options->gss_authentication=-1;
+ options->gss_keyex = -1;
options->gss_cleanup_creds = -1;
options->gss_strict_acceptor = -1;
+ options->gss_store_rekey = -1;
options->password_authentication = -1;
options->kbd_interactive_authentication = -1;
options->challenge_response_authentication = -1;
@@ -323,10 +325,14 @@ fill_default_server_options(ServerOptions *options)
options->kerberos_get_afs_token = 0;
if (options->gss_authentication == -1)
options->gss_authentication = 0;
+ if (options->gss_keyex == -1)
+ options->gss_keyex = 0;
if (options->gss_cleanup_creds == -1)
options->gss_cleanup_creds = 1;
if (options->gss_strict_acceptor == -1)
options->gss_strict_acceptor = 0;
+ if (options->gss_store_rekey == -1)
+ options->gss_store_rekey = 0;
if (options->password_authentication == -1)
options->password_authentication = 1;
if (options->kbd_interactive_authentication == -1)
@@ -457,6 +463,7 @@ typedef enum {
sHostKeyAlgorithms,
sClientAliveInterval, sClientAliveCountMax, sAuthorizedKeysFile,
sGssAuthentication, sGssCleanupCreds, sGssStrictAcceptor,
+ sGssKeyEx, sGssStoreRekey,
sAcceptEnv, sPermitTunnel,
sMatch, sPermitOpen, sForceCommand, sChrootDirectory,
sUsePrivilegeSeparation, sAllowAgentForwarding,
@@ -534,11 +541,17 @@ static struct {
{ "gssapiauthentication", sGssAuthentication, SSHCFG_ALL },
{ "gssapicleanupcredentials", sGssCleanupCreds, SSHCFG_GLOBAL },
{ "gssapistrictacceptorcheck", sGssStrictAcceptor, SSHCFG_GLOBAL },
+ { "gssapikeyexchange", sGssKeyEx, SSHCFG_GLOBAL },
+ { "gssapistorecredentialsonrekey", sGssStoreRekey, SSHCFG_GLOBAL },
#else
{ "gssapiauthentication", sUnsupported, SSHCFG_ALL },
{ "gssapicleanupcredentials", sUnsupported, SSHCFG_GLOBAL },
{ "gssapistrictacceptorcheck", sUnsupported, SSHCFG_GLOBAL },
+ { "gssapikeyexchange", sUnsupported, SSHCFG_GLOBAL },
+ { "gssapistorecredentialsonrekey", sUnsupported, SSHCFG_GLOBAL },
#endif
+ { "gssusesessionccache", sUnsupported, SSHCFG_GLOBAL },
+ { "gssapiusesessioncredcache", sUnsupported, SSHCFG_GLOBAL },
{ "passwordauthentication", sPasswordAuthentication, SSHCFG_ALL },
{ "kbdinteractiveauthentication", sKbdInteractiveAuthentication, SSHCFG_ALL },
{ "challengeresponseauthentication", sChallengeResponseAuthentication, SSHCFG_GLOBAL },
@@ -1287,6 +1300,10 @@ process_server_config_line(ServerOptions *options, char *line,
intptr = &options->gss_authentication;
goto parse_flag;
+ case sGssKeyEx:
+ intptr = &options->gss_keyex;
+ goto parse_flag;
+
case sGssCleanupCreds:
intptr = &options->gss_cleanup_creds;
goto parse_flag;
@@ -1295,6 +1312,10 @@ process_server_config_line(ServerOptions *options, char *line,
intptr = &options->gss_strict_acceptor;
goto parse_flag;
+ case sGssStoreRekey:
+ intptr = &options->gss_store_rekey;
+ goto parse_flag;
+
case sPasswordAuthentication:
intptr = &options->password_authentication;
goto parse_flag;
@@ -2056,6 +2077,10 @@ copy_set_server_options(ServerOptions *dst, ServerOptions *src, int preauth)
M_CP_INTOPT(password_authentication);
M_CP_INTOPT(gss_authentication);
+ M_CP_INTOPT(gss_keyex);
+ M_CP_INTOPT(gss_cleanup_creds);
+ M_CP_INTOPT(gss_strict_acceptor);
+ M_CP_INTOPT(gss_store_rekey);
M_CP_INTOPT(rsa_authentication);
M_CP_INTOPT(pubkey_authentication);
M_CP_INTOPT(kerberos_authentication);
@@ -2343,7 +2368,10 @@ dump_config(ServerOptions *o)
#endif
#ifdef GSSAPI
dump_cfg_fmtint(sGssAuthentication, o->gss_authentication);
+ dump_cfg_fmtint(sGssKeyEx, o->gss_keyex);
dump_cfg_fmtint(sGssCleanupCreds, o->gss_cleanup_creds);
+ dump_cfg_fmtint(sGssStrictAcceptor, o->gss_strict_acceptor);
+ dump_cfg_fmtint(sGssStoreRekey, o->gss_store_rekey);
#endif
dump_cfg_fmtint(sPasswordAuthentication, o->password_authentication);
dump_cfg_fmtint(sKbdInteractiveAuthentication,
diff --git a/servconf.h b/servconf.h
index 7e02dbda..c19858c5 100644
--- a/servconf.h
+++ b/servconf.h
@@ -16,6 +16,8 @@
#ifndef SERVCONF_H
#define SERVCONF_H
+#include "misc.h"
+
#define MAX_PORTS 256 /* Max # ports. */
#define MAX_ALLOW_USERS 256 /* Max # users on allow list. */
@@ -119,8 +121,10 @@ typedef struct {
int kerberos_get_afs_token; /* If true, try to get AFS token if
* authenticated with Kerberos. */
int gss_authentication; /* If true, permit GSSAPI authentication */
+ int gss_keyex; /* If true, permit GSSAPI key exchange */
int gss_cleanup_creds; /* If true, destroy cred cache on logout */
int gss_strict_acceptor; /* If true, restrict the GSSAPI acceptor name */
+ int gss_store_rekey;
int password_authentication; /* If true, permit password
* authentication. */
int kbd_interactive_authentication; /* If true, permit */
diff --git a/ssh-gss.h b/ssh-gss.h
index a99d7f08..0374c88b 100644
--- a/ssh-gss.h
+++ b/ssh-gss.h
@@ -1,6 +1,6 @@
/* $OpenBSD: ssh-gss.h,v 1.11 2014/02/26 20:28:44 djm Exp $ */
/*
- * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
+ * Copyright (c) 2001-2009 Simon Wilkinson. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
@@ -61,10 +61,22 @@
#define SSH_GSS_OIDTYPE 0x06
+#define SSH2_MSG_KEXGSS_INIT 30
+#define SSH2_MSG_KEXGSS_CONTINUE 31
+#define SSH2_MSG_KEXGSS_COMPLETE 32
+#define SSH2_MSG_KEXGSS_HOSTKEY 33
+#define SSH2_MSG_KEXGSS_ERROR 34
+#define SSH2_MSG_KEXGSS_GROUPREQ 40
+#define SSH2_MSG_KEXGSS_GROUP 41
+#define KEX_GSS_GRP1_SHA1_ID "gss-group1-sha1-"
+#define KEX_GSS_GRP14_SHA1_ID "gss-group14-sha1-"
+#define KEX_GSS_GEX_SHA1_ID "gss-gex-sha1-"
+
typedef struct {
char *filename;
char *envvar;
char *envval;
+ struct passwd *owner;
void *data;
} ssh_gssapi_ccache;
@@ -72,8 +84,11 @@ typedef struct {
gss_buffer_desc displayname;
gss_buffer_desc exportedname;
gss_cred_id_t creds;
+ gss_name_t name;
struct ssh_gssapi_mech_struct *mech;
ssh_gssapi_ccache store;
+ int used;
+ int updated;
} ssh_gssapi_client;
typedef struct ssh_gssapi_mech_struct {
@@ -84,6 +99,7 @@ typedef struct ssh_gssapi_mech_struct {
int (*userok) (ssh_gssapi_client *, char *);
int (*localname) (ssh_gssapi_client *, char **);
void (*storecreds) (ssh_gssapi_client *);
+ int (*updatecreds) (ssh_gssapi_ccache *, ssh_gssapi_client *);
} ssh_gssapi_mech;
typedef struct {
@@ -94,10 +110,11 @@ typedef struct {
gss_OID oid; /* client */
gss_cred_id_t creds; /* server */
gss_name_t client; /* server */
- gss_cred_id_t client_creds; /* server */
+ gss_cred_id_t client_creds; /* both */
} Gssctxt;
extern ssh_gssapi_mech *supported_mechs[];
+extern Gssctxt *gss_kex_context;
int ssh_gssapi_check_oid(Gssctxt *, void *, size_t);
void ssh_gssapi_set_oid_data(Gssctxt *, void *, size_t);
@@ -119,16 +136,30 @@ void ssh_gssapi_build_ctx(Gssctxt **);
void ssh_gssapi_delete_ctx(Gssctxt **);
OM_uint32 ssh_gssapi_sign(Gssctxt *, gss_buffer_t, gss_buffer_t);
void ssh_gssapi_buildmic(Buffer *, const char *, const char *, const char *);
-int ssh_gssapi_check_mechanism(Gssctxt **, gss_OID, const char *);
+int ssh_gssapi_check_mechanism(Gssctxt **, gss_OID, const char *, const char *);
+OM_uint32 ssh_gssapi_client_identity(Gssctxt *, const char *);
+int ssh_gssapi_credentials_updated(Gssctxt *);
/* In the server */
+typedef int ssh_gssapi_check_fn(Gssctxt **, gss_OID, const char *,
+ const char *);
+char *ssh_gssapi_client_mechanisms(const char *, const char *);
+char *ssh_gssapi_kex_mechs(gss_OID_set, ssh_gssapi_check_fn *, const char *,
+ const char *);
+gss_OID ssh_gssapi_id_kex(Gssctxt *, char *, int);
+int ssh_gssapi_server_check_mech(Gssctxt **,gss_OID, const char *,
+ const char *);
OM_uint32 ssh_gssapi_server_ctx(Gssctxt **, gss_OID);
-int ssh_gssapi_userok(char *name);
+int ssh_gssapi_userok(char *name, struct passwd *);
OM_uint32 ssh_gssapi_checkmic(Gssctxt *, gss_buffer_t, gss_buffer_t);
void ssh_gssapi_do_child(char ***, u_int *);
void ssh_gssapi_cleanup_creds(void);
void ssh_gssapi_storecreds(void);
+char *ssh_gssapi_server_mechanisms(void);
+int ssh_gssapi_oid_table_ok();
+
+int ssh_gssapi_update_creds(ssh_gssapi_ccache *store);
#endif /* GSSAPI */
#endif /* _SSH_GSS_H */
diff --git a/ssh_config b/ssh_config
index 1e32413b..ed4d7658 100644
--- a/ssh_config
+++ b/ssh_config
@@ -47,6 +47,8 @@ Host *
# HostbasedAuthentication no
# GSSAPIAuthentication no
# GSSAPIDelegateCredentials no
+# GSSAPIKeyExchange no
+# GSSAPITrustDNS no
# BatchMode no
# CheckHostIP yes
# AddressFamily any
diff --git a/ssh_config.0 b/ssh_config.0
index 3c0ffe78..3592e880 100644
--- a/ssh_config.0
+++ b/ssh_config.0
@@ -450,10 +450,41 @@ DESCRIPTION
Specifies whether user authentication based on GSSAPI is allowed.
The default is M-bM-^@M-^\noM-bM-^@M-^].
+ GSSAPIKeyExchange
+ Specifies whether key exchange based on GSSAPI may be used. When
+ using GSSAPI key exchange the server need not have a host key.
+ The default is no.
+ Note that this option applies to protocol version 2 only.
+
+ GSSAPIClientIdentity
+ If set, specifies the GSSAPI client identity that ssh should use
+ when connecting to the server. The default is unset, which means
+ that the default identity will be used.
+
+ GSSAPIServerIdentity
+ If set, specifies the GSSAPI server identity that ssh should expect
+ when connecting to the server. The default is unset, which means
+ that the expected GSSAPI server identity will be determined from
+ the target hostname.
+
GSSAPIDelegateCredentials
Forward (delegate) credentials to the server. The default is
M-bM-^@M-^\noM-bM-^@M-^].
+ GSSAPIRenewalForcesRekey
+ If set to yes then renewal of the client's GSSAPI credentials will
+ force the rekeying of the ssh connection. With a compatible server,
+ this can delegate the renewed credentials to a session on the
+ server. The default is no.
+
+ GSSAPITrustDns
+ Set to yes to indicate that the DNS is trusted to securely
+ canonicalize the name of the host being connected to. If no, the
+ hostname entered on the command line will be passed untouched to
+ the GSSAPI library. The default is no.
+ This option only applies to protocol version 2 connections using
+ GSSAPI.
+
HashKnownHosts
Indicates that ssh(1) should hash host names and addresses when
they are added to ~/.ssh/known_hosts. These hashed names may be
diff --git a/ssh_config.5 b/ssh_config.5
index 02399493..77891a12 100644
--- a/ssh_config.5
+++ b/ssh_config.5
@@ -828,10 +828,42 @@ The default is
Specifies whether user authentication based on GSSAPI is allowed.
The default is
.Dq no .
+.It Cm GSSAPIKeyExchange
+Specifies whether key exchange based on GSSAPI may be used. When using
+GSSAPI key exchange the server need not have a host key.
+The default is
+.Dq no .
+Note that this option applies to protocol version 2 only.
+.It Cm GSSAPIClientIdentity
+If set, specifies the GSSAPI client identity that ssh should use when
+connecting to the server. The default is unset, which means that the default
+identity will be used.
+.It Cm GSSAPIServerIdentity
+If set, specifies the GSSAPI server identity that ssh should expect when
+connecting to the server. The default is unset, which means that the
+expected GSSAPI server identity will be determined from the target
+hostname.
.It Cm GSSAPIDelegateCredentials
Forward (delegate) credentials to the server.
The default is
.Dq no .
+.It Cm GSSAPIRenewalForcesRekey
+If set to
+.Dq yes
+then renewal of the client's GSSAPI credentials will force the rekeying of the
+ssh connection. With a compatible server, this can delegate the renewed
+credentials to a session on the server.
+The default is
+.Dq no .
+.It Cm GSSAPITrustDns
+Set to
+.Dq yes to indicate that the DNS is trusted to securely canonicalize
+the name of the host being connected to. If
+.Dq no, the hostname entered on the
+command line will be passed untouched to the GSSAPI library.
+The default is
+.Dq no .
+This option only applies to protocol version 2 connections using GSSAPI.
.It Cm HashKnownHosts
Indicates that
.Xr ssh 1
diff --git a/sshconnect2.c b/sshconnect2.c
index f79c96be..088d42a6 100644
--- a/sshconnect2.c
+++ b/sshconnect2.c
@@ -160,6 +160,10 @@ ssh_kex2(char *host, struct sockaddr *hostaddr, u_short port)
char *s;
struct kex *kex;
int r;
+#ifdef GSSAPI
+ char *orig = NULL, *gss = NULL;
+ char *gss_host = NULL;
+#endif
xxx_host = host;
xxx_hostaddr = hostaddr;
@@ -167,6 +171,28 @@ ssh_kex2(char *host, struct sockaddr *hostaddr, u_short port)
if ((s = kex_names_cat(options.kex_algorithms, "ext-info-c")) == NULL)
fatal("%s: kex_names_cat", __func__);
myproposal[PROPOSAL_KEX_ALGS] = compat_kex_proposal(s);
+
+#ifdef GSSAPI
+ if (options.gss_keyex) {
+ /* 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);
+ myproposal[PROPOSAL_KEX_ALGS] = kex_names_cat(gss, orig);
+ free(orig);
+ }
+ }
+#endif
+
myproposal[PROPOSAL_ENC_ALGS_CTOS] =
compat_cipher_proposal(options.ciphers);
myproposal[PROPOSAL_ENC_ALGS_STOC] =
@@ -195,6 +221,18 @@ ssh_kex2(char *host, struct sockaddr *hostaddr, u_short port)
order_hostkeyalgs(host, hostaddr, port));
}
+#ifdef GSSAPI
+ /* 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];
+ myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
+ kex_names_cat(myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS], "null");
+ free(orig);
+ free(gss);
+ }
+#endif
+
if (options.rekey_limit || options.rekey_interval)
packet_set_rekey_limits((u_int32_t)options.rekey_limit,
(time_t)options.rekey_interval);
@@ -213,10 +251,30 @@ ssh_kex2(char *host, struct sockaddr *hostaddr, u_short port)
# endif
#endif
kex->kex[KEX_C25519_SHA256] = kexc25519_client;
+#ifdef GSSAPI
+ 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
+ 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;
+ if (options.gss_server_identity) {
+ kex->gss_host = options.gss_server_identity;
+ } else {
+ kex->gss_host = gss_host;
+ }
+ }
+#endif
+
dispatch_run(DISPATCH_BLOCK, &kex->done, active_state);
/* remove ext-info from the KEX proposals for rekeying */
@@ -311,6 +369,7 @@ int input_gssapi_token(int type, u_int32_t, void *);
int input_gssapi_hash(int type, u_int32_t, void *);
int input_gssapi_error(int, u_int32_t, void *);
int input_gssapi_errtok(int, u_int32_t, void *);
+int userauth_gsskeyex(Authctxt *authctxt);
#endif
void userauth(Authctxt *, char *);
@@ -326,6 +385,11 @@ static char *authmethods_get(void);
Authmethod authmethods[] = {
#ifdef GSSAPI
+ {"gssapi-keyex",
+ userauth_gsskeyex,
+ NULL,
+ &options.gss_authentication,
+ NULL},
{"gssapi-with-mic",
userauth_gssapi,
NULL,
@@ -656,19 +720,31 @@ userauth_gssapi(Authctxt *authctxt)
static u_int mech = 0;
OM_uint32 min;
int ok = 0;
+ const char *gss_host;
+
+ if (options.gss_server_identity)
+ gss_host = options.gss_server_identity;
+ else if (options.gss_trust_dns)
+ gss_host = get_canonical_hostname(1);
+ else
+ gss_host = authctxt->host;
/* Try one GSSAPI method at a time, rather than sending them all at
* once. */
if (gss_supported == NULL)
- gss_indicate_mechs(&min, &gss_supported);
+ 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], authctxt->host)) {
+ ssh_gssapi_check_mechanism(&gssctxt,
+ &gss_supported->elements[mech], gss_host,
+ options.gss_client_identity)) {
ok = 1; /* Mechanism works */
} else {
mech++;
@@ -765,8 +841,8 @@ input_gssapi_response(int type, u_int32_t plen, void *ctxt)
{
Authctxt *authctxt = ctxt;
Gssctxt *gssctxt;
- int oidlen;
- char *oidv;
+ u_int oidlen;
+ u_char *oidv;
if (authctxt == NULL)
fatal("input_gssapi_response: no authentication context");
@@ -879,6 +955,48 @@ input_gssapi_error(int type, u_int32_t plen, void *ctxt)
free(lang);
return 0;
}
+
+int
+userauth_gsskeyex(Authctxt *authctxt)
+{
+ 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);
+ }
+
+ ssh_gssapi_buildmic(&b, authctxt->server_user, authctxt->service,
+ "gssapi-keyex");
+
+ 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);
+ packet_put_cstring(authctxt->server_user);
+ 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
diff --git a/sshd.c b/sshd.c
index 8d3a42d9..e5251eb1 100644
--- a/sshd.c
+++ b/sshd.c
@@ -129,6 +129,10 @@
#include "fips.h"
+#ifdef USE_SECURITY_SESSION_API
+#include <Security/AuthSession.h>
+#endif
+
#ifndef O_NOCTTY
#define O_NOCTTY 0
#endif
@@ -1856,10 +1860,13 @@ main(int ac, char **av)
logit("Disabling protocol version 1. Could not load host key");
options.protocol &= ~SSH_PROTO_1;
}
+#ifndef GSSAPI
+ /* The GSSAPI key exchange can run without a host key */
if ((options.protocol & SSH_PROTO_2) && !sensitive_data.have_ssh2_key) {
logit("Disabling protocol version 2. Could not load host key");
options.protocol &= ~SSH_PROTO_2;
}
+#endif
if (!(options.protocol & (SSH_PROTO_1|SSH_PROTO_2))) {
logit("sshd: no hostkeys available -- exiting.");
exit(1);
@@ -2064,6 +2071,60 @@ main(int ac, char **av)
/* This is the child processing a new connection. */
setproctitle("%s", "[accepted]");
+#ifdef USE_SECURITY_SESSION_API
+ /*
+ * Create a new security session for use by the new user login if
+ * the current session is the root session or we are not launched
+ * by inetd (eg: debugging mode or server mode). We do not
+ * necessarily need to create a session if we are launched from
+ * inetd because Panther xinetd will create a session for us.
+ *
+ * The only case where this logic will fail is if there is an
+ * inetd running in a non-root session which is not creating
+ * new sessions for us. Then all the users will end up in the
+ * same session (bad).
+ *
+ * When the client exits, the session will be destroyed for us
+ * automatically.
+ *
+ * We must create the session before any credentials are stored
+ * (including AFS pags, which happens a few lines below).
+ */
+ {
+ OSStatus err = 0;
+ SecuritySessionId sid = 0;
+ SessionAttributeBits sattrs = 0;
+
+ err = SessionGetInfo(callerSecuritySession, &sid, &sattrs);
+ if (err)
+ error("SessionGetInfo() failed with error %.8X",
+ (unsigned) err);
+ else
+ debug("Current Session ID is %.8X / Session Attributes are %.8X",
+ (unsigned) sid, (unsigned) sattrs);
+
+ if (inetd_flag && !(sattrs & sessionIsRoot))
+ debug("Running in inetd mode in a non-root session... "
+ "assuming inetd created the session for us.");
+ else {
+ debug("Creating new security session...");
+ err = SessionCreate(0, sessionHasTTY | sessionIsRemote);
+ if (err)
+ error("SessionCreate() failed with error %.8X",
+ (unsigned) err);
+
+ err = SessionGetInfo(callerSecuritySession, &sid,
+ &sattrs);
+ if (err)
+ error("SessionGetInfo() failed with error %.8X",
+ (unsigned) err);
+ else
+ debug("New Session ID is %.8X / Session Attributes are %.8X",
+ (unsigned) sid, (unsigned) sattrs);
+ }
+ }
+#endif
+
/*
* Create a new session and process group since the 4.4BSD
* setlogin() affects the entire process group. We don't
@@ -2174,6 +2235,60 @@ main(int ac, char **av)
remote_ip, remote_port, laddr, get_local_port());
free(laddr);
+#ifdef USE_SECURITY_SESSION_API
+ /*
+ * Create a new security session for use by the new user login if
+ * the current session is the root session or we are not launched
+ * by inetd (eg: debugging mode or server mode). We do not
+ * necessarily need to create a session if we are launched from
+ * inetd because Panther xinetd will create a session for us.
+ *
+ * The only case where this logic will fail is if there is an
+ * inetd running in a non-root session which is not creating
+ * new sessions for us. Then all the users will end up in the
+ * same session (bad).
+ *
+ * When the client exits, the session will be destroyed for us
+ * automatically.
+ *
+ * We must create the session before any credentials are stored
+ * (including AFS pags, which happens a few lines below).
+ */
+ {
+ OSStatus err = 0;
+ SecuritySessionId sid = 0;
+ SessionAttributeBits sattrs = 0;
+
+ err = SessionGetInfo(callerSecuritySession, &sid, &sattrs);
+ if (err)
+ error("SessionGetInfo() failed with error %.8X",
+ (unsigned) err);
+ else
+ debug("Current Session ID is %.8X / Session Attributes are %.8X",
+ (unsigned) sid, (unsigned) sattrs);
+
+ if (inetd_flag && !(sattrs & sessionIsRoot))
+ debug("Running in inetd mode in a non-root session... "
+ "assuming inetd created the session for us.");
+ else {
+ debug("Creating new security session...");
+ err = SessionCreate(0, sessionHasTTY | sessionIsRemote);
+ if (err)
+ error("SessionCreate() failed with error %.8X",
+ (unsigned) err);
+
+ err = SessionGetInfo(callerSecuritySession, &sid,
+ &sattrs);
+ if (err)
+ error("SessionGetInfo() failed with error %.8X",
+ (unsigned) err);
+ else
+ debug("New Session ID is %.8X / Session Attributes are %.8X",
+ (unsigned) sid, (unsigned) sattrs);
+ }
+ }
+#endif
+
/*
* We don't want to listen forever unless the other side
* successfully authenticates itself. So we set up an alarm which is
@@ -2594,6 +2709,48 @@ do_ssh2_kex(void)
myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = compat_pkalg_proposal(
list_hostkey_types());
+#ifdef GSSAPI
+ {
+ char *orig;
+ char *gss = NULL;
+ char *newstr = NULL;
+ orig = myproposal[PROPOSAL_KEX_ALGS];
+
+ /*
+ * If we don't have a host key, then there's no point advertising
+ * the other key exchange algorithms
+ */
+
+ if (strlen(myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS]) == 0)
+ orig = NULL;
+
+ if (options.gss_keyex)
+ gss = ssh_gssapi_server_mechanisms();
+ else
+ gss = NULL;
+
+ if (gss && orig)
+ xasprintf(&newstr, "%s,%s", gss, orig);
+ else if (gss)
+ newstr = gss;
+ else if (orig)
+ newstr = orig;
+
+ /*
+ * If we've got GSSAPI mechanisms, then we've got the 'null' host
+ * key alg, but we can't tell people about it unless its the only
+ * host key algorithm we support
+ */
+ if (gss && (strlen(myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS])) == 0)
+ myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = "null";
+
+ if (newstr)
+ myproposal[PROPOSAL_KEX_ALGS] = newstr;
+ else
+ fatal("No supported key exchange algorithms");
+ }
+#endif
+
/* start key exchange */
if ((r = kex_setup(active_state, myproposal)) != 0)
fatal("kex_setup: %s", ssh_err(r));
@@ -2608,6 +2765,13 @@ do_ssh2_kex(void)
# endif
#endif
kex->kex[KEX_C25519_SHA256] = kexc25519_server;
+#ifdef GSSAPI
+ if (options.gss_keyex) {
+ kex->kex[KEX_GSS_GRP1_SHA1] = kexgss_server;
+ kex->kex[KEX_GSS_GRP14_SHA1] = kexgss_server;
+ kex->kex[KEX_GSS_GEX_SHA1] = kexgss_server;
+ }
+#endif
kex->server = 1;
kex->client_version_string=client_version_string;
kex->server_version_string=server_version_string;
diff --git a/sshd_config b/sshd_config
index 9dabdf1f..97709a3a 100644
--- a/sshd_config
+++ b/sshd_config
@@ -89,6 +89,8 @@ PasswordAuthentication no
# GSSAPI options
#GSSAPIAuthentication no
#GSSAPICleanupCredentials yes
+#GSSAPIStrictAcceptorCheck yes
+#GSSAPIKeyExchange no
# Set this to 'yes' to enable PAM authentication, account processing,
# and session processing. If this is enabled, PAM authentication will
diff --git a/sshd_config.0 b/sshd_config.0
index 120a5cf3..66de1fdd 100644
--- a/sshd_config.0
+++ b/sshd_config.0
@@ -380,6 +380,12 @@ DESCRIPTION
Specifies whether user authentication based on GSSAPI is allowed.
The default is M-bM-^@M-^\noM-bM-^@M-^].
+ GSSAPIKeyExchange
+ Specifies whether key exchange based on GSSAPI is allowed. GSSAPI
+ key exchange doesn't rely on ssh keys to verify host identity. The
+ default is no.
+ Note that this option applies to protocol version 2 only.
+
GSSAPICleanupCredentials
Specifies whether to automatically destroy the user's credentials
cache on logout. The default is M-bM-^@M-^\yesM-bM-^@M-^].
@@ -393,6 +399,12 @@ DESCRIPTION
default store. This facility is provided to assist with
operation on multi homed machines. The default is M-bM-^@M-^\yesM-bM-^@M-^].
+ GSSAPIStoreCredentialsOnRekey
+ Controls whether the user's GSSAPI credentials should be updated
+ following a successful connection rekeying. This option can be used
+ to accepted renewed or updated credentials from a compatible
+ client. The default is no.
+
HostbasedAcceptedKeyTypes
Specifies the key types that will be accepted for hostbased
authentication as a comma-separated pattern list. Alternately if
diff --git a/sshd_config.5 b/sshd_config.5
index 0dd23d4f..70a7f3cd 100644
--- a/sshd_config.5
+++ b/sshd_config.5
@@ -624,6 +624,12 @@ The default is
Specifies whether user authentication based on GSSAPI is allowed.
The default is
.Dq no .
+.It Cm GSSAPIKeyExchange
+Specifies whether key exchange based on GSSAPI is allowed. GSSAPI key exchange
+doesn't rely on ssh keys to verify host identity.
+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.
@@ -644,6 +650,11 @@ machine's default store.
This facility is provided to assist with operation on multi homed machines.
The default is
.Dq yes .
+.It Cm GSSAPIStoreCredentialsOnRekey
+Controls whether the user's GSSAPI credentials should be updated following a
+successful connection rekeying. This option can be used to accepted renewed
+or updated credentials from a compatible client. The default is
+.Dq no .
.It Cm HostbasedAcceptedKeyTypes
Specifies the key types that will be accepted for hostbased authentication
as a comma-separated pattern list.
diff --git a/sshkey.c b/sshkey.c
index 87b093e9..8dce9add 100644
--- a/sshkey.c
+++ b/sshkey.c
@@ -115,6 +115,8 @@ static const struct keytype keytypes[] = {
# endif /* OPENSSL_HAS_NISTP521 */
# endif /* OPENSSL_HAS_ECC */
#endif /* WITH_OPENSSL */
+ { "null", "null",
+ KEY_NULL, 0, 0 },
{ NULL, NULL, -1, -1, 0, 0 }
};
diff --git a/sshkey.h b/sshkey.h
index a20a14f9..2259cbb6 100644
--- a/sshkey.h
+++ b/sshkey.h
@@ -62,6 +62,7 @@ enum sshkey_types {
KEY_DSA_CERT,
KEY_ECDSA_CERT,
KEY_ED25519_CERT,
+ KEY_NULL,
KEY_UNSPEC
};
--
2.38.0
