]> andersk Git - gssapi-openssh.git/commitdiff
GSSAPI patch for OpenSSH 3.0.2p1 Protocol version 2 by Simon Wilkinson from OPENSSH_3_0_2P1_GSSAPI
authorjbasney <jbasney>
Mon, 11 Mar 2002 15:28:15 +0000 (15:28 +0000)
committerjbasney <jbasney>
Mon, 11 Mar 2002 15:28:15 +0000 (15:28 +0000)
http://www.sxw.org.uk/computing/patches/openssh-3.0.2p1-gssapi.patch

25 files changed:
openssh/Makefile.in
openssh/acconfig.h
openssh/auth-pam.c
openssh/auth-pam.h
openssh/auth.h
openssh/auth2.c
openssh/configure.ac
openssh/gss-genr.c [new file with mode: 0644]
openssh/gss-serv.c [new file with mode: 0644]
openssh/kex.c
openssh/kex.h
openssh/kexgss.c [new file with mode: 0644]
openssh/key.c
openssh/key.h
openssh/makegssname.pl [new file with mode: 0644]
openssh/readconf.c
openssh/readconf.h
openssh/servconf.c
openssh/servconf.h
openssh/session.c
openssh/session.h
openssh/ssh-gss.h [new file with mode: 0644]
openssh/sshconnect2.c
openssh/sshd.8
openssh/sshd.c

index 87a7c13981a07652c996f421be68b08ee9a069af..f4ab6f0be1a3b16eddd69f33b63f91effc0a79e3 100644 (file)
@@ -46,11 +46,11 @@ INSTALL_SSH_PRNG_CMDS=@INSTALL_SSH_PRNG_CMDS@
 
 TARGETS=ssh$(EXEEXT) sshd$(EXEEXT) ssh-add$(EXEEXT) ssh-keygen$(EXEEXT) ssh-keyscan${EXEEXT} ssh-agent$(EXEEXT) scp$(EXEEXT) $(SFTP_PROGS)
 
-LIBSSH_OBJS=atomicio.o authfd.o authfile.o bufaux.o buffer.o canohost.o channels.o cipher.o compat.o compress.o crc32.o deattack.o dh.o dispatch.o mac.o hostfile.o key.o kex.o kexdh.o kexgex.o log.o match.o misc.o mpaux.o nchan.o packet.o radix.o rijndael.o entropy.o readpass.o rsa.o scard.o ssh-dss.o ssh-rsa.o tildexpand.o ttymodes.o uidswap.o uuencode.o xmalloc.o 
+LIBSSH_OBJS=atomicio.o authfd.o authfile.o bufaux.o buffer.o canohost.o channels.o cipher.o compat.o compress.o crc32.o deattack.o dh.o dispatch.o mac.o hostfile.o key.o kex.o kexdh.o kexgex.o kexgss.o log.o match.o misc.o mpaux.o nchan.o packet.o radix.o rijndael.o entropy.o readpass.o rsa.o scard.o ssh-dss.o ssh-rsa.o tildexpand.o ttymodes.o uidswap.o uuencode.o xmalloc.o gss-genr.o
 
 SSHOBJS= ssh.o sshconnect.o sshconnect1.o sshconnect2.o sshtty.o readconf.o clientloop.o
 
-SSHDOBJS= sshd.o auth.o auth1.o auth2.o auth-chall.o auth2-chall.o auth-rhosts.o auth-options.o auth-krb4.o auth-krb5.o auth-pam.o auth2-pam.o auth-passwd.o auth-rsa.o auth-rh-rsa.o auth-sia.o sshpty.o sshlogin.o loginrec.o servconf.o serverloop.o md5crypt.o session.o groupaccess.o auth-skey.o auth-bsdauth.o
+SSHDOBJS= sshd.o auth.o auth1.o auth2.o auth-chall.o auth2-chall.o auth-rhosts.o auth-options.o auth-krb4.o auth-krb5.o auth-pam.o auth2-pam.o auth-passwd.o auth-rsa.o auth-rh-rsa.o auth-sia.o sshpty.o sshlogin.o loginrec.o servconf.o serverloop.o md5crypt.o session.o groupaccess.o auth-skey.o auth-bsdauth.o gss-serv.o
 
 MANPAGES       = scp.1.out ssh-add.1.out ssh-agent.1.out ssh-keygen.1.out ssh-keyscan.1.out ssh.1.out sshd.8.out sftp-server.8.out sftp.1.out
 MANPAGES_IN    = scp.1 ssh-add.1 ssh-agent.1 ssh-keygen.1 ssh-keyscan.1 ssh.1 sshd.8 sftp-server.8 sftp.1
index 405f20016b87ca5aadf8baad7170d31855a88f2f..84e0e64471d4db3c90a4b8e1f96fed0fe5c14c01 100644 (file)
 /* Define if libc defines __progname */
 #undef HAVE___PROGNAME
 
+/* Define this is you want GSSAPI support in the version 2 protocol */
+#undef GSSAPI
+
 /* Define if you want Kerberos 5 support */
 #undef KRB5
 
 /* Define if you want AFS support */
 #undef AFS
 
+/* Define if you want GSI/Globus authentication support */
+#undef GSI
+
 /* Define if you want S/Key support */
 #undef SKEY
 
index 801c9eb64b4c8d6c9e0dbc9bdccb59da77146085..8e170d40955bbda5225e2659c100ab8c2bcaf66e 100644 (file)
@@ -394,6 +394,24 @@ char **fetch_pam_environment(void)
 #endif /* HAVE_PAM_GETENVLIST */
 }
 
+/* Set a PAM environment string. We need to do this so that the session
+ * modules can handle things like Kerberos/GSI credentials that appear
+ * during the ssh authentication process.
+ */
+
+int do_pam_putenv(char *name, char *value) {
+       char *compound;
+       int ret=1;
+       
+       compound=xmalloc(strlen(name)+strlen(value)+2);
+       if (compound) {
+               sprintf(compound,"%s=%s",name,value);
+               ret=pam_putenv(__pamh,compound);
+               xfree(compound);
+       }
+       return(ret);
+}
+
 /* Print any messages that have been generated during authentication */
 /* or account checking to stderr */
 void print_pam_messages(void)
index 30e4df51081077b7ae1a30827589a054981e8a7d..de27b8368cc3b44086ec007c4f6eaf37a53d1bf5 100644 (file)
@@ -17,6 +17,7 @@ void print_pam_messages(void);
 int is_pam_password_change_required(void);
 void do_pam_chauthtok(void);
 void do_pam_set_conv(struct pam_conv *);
+int do_pam_putenv(char *, char *);
 void message_cat(char **p, const char *a);
 
 #endif /* USE_PAM */
index edfc9fb551eeb7e9ddcfaa5adbbb8c4a1c6f98c9..656918ed02b2c6cd56fda8c500caf43900d29c94 100644 (file)
@@ -67,6 +67,7 @@ struct Authctxt {
        krb5_principal   krb5_user;
        char            *krb5_ticket_file;
 #endif
+       void *methoddata;
 };
 
 /*
index 1920eb32e0ad9e14e842201348681ec6d8efaabb..2fbe819e193f74dcb6d70d772ea1b4718d9642da 100644 (file)
@@ -52,6 +52,10 @@ RCSID("$OpenBSD: auth2.c,v 1.72 2001/11/07 22:41:51 markus Exp $");
 #include "canohost.h"
 #include "match.h"
 
+#ifdef GSSAPI
+#include "ssh-gss.h"
+#endif
+
 /* import */
 extern ServerOptions options;
 extern u_char *session_id2;
@@ -87,10 +91,23 @@ static int userauth_pubkey(Authctxt *);
 static int userauth_hostbased(Authctxt *);
 static int userauth_kbdint(Authctxt *);
 
+#ifdef GSSAPI
+int    userauth_external(Authctxt *authctxt);
+int    userauth_gssapi(Authctxt *authctxt);
+#endif
+
 Authmethod authmethods[] = {
        {"none",
                userauth_none,
                &one},
+#ifdef GSSAPI
+       {"external-keyx",
+               userauth_external,
+               &options.gss_authentication},
+       {"gssapi",
+               userauth_gssapi,
+               &options.gss_authentication},
+#endif
        {"publickey",
                userauth_pubkey,
                &options.pubkey_authentication},
@@ -221,6 +238,12 @@ input_userauth_request(int type, int plen, void *ctxt)
        }
        /* reset state */
        dispatch_set(SSH2_MSG_USERAUTH_INFO_RESPONSE, &protocol_error);
+
+#ifdef GSSAPI
+       dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &protocol_error);
+       dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, &protocol_error);
+#endif
+
        authctxt->postponed = 0;
 #ifdef BSD_AUTH
        if (authctxt->as) {
index ca36df16ad3891c5dd1db70f3add12054ccaff7b..717d19d08f7c021ff7085293f132ca49eea06abd 100644 (file)
@@ -490,6 +490,92 @@ int main(void){struct dirent d;return(sizeof(d.d_name)<=sizeof(char));}
        ]
 )
 
+# Check whether the user wants GSI (Globus) support
+gsi_path="no"
+AC_ARG_WITH(gsi,
+       [  --with-gsi=PATH         Enable GSI/Globus authentication support],
+       [
+               gsi_path="$withval"
+       ]
+)
+
+AC_ARG_WITH(globus,
+       [  --with-globus=PATH      Enable GSI/Globus authentication support],
+       [
+               gsi_path="$withval"
+       ]
+)
+
+if test "x$gsi_path" != "xno" ; then
+       # Globus GSSAPI configuration
+       AC_DEFINE(GSSAPI)
+       AC_DEFINE(GSI)
+
+       # Find GLOBUS/GSI installation Directory
+       AC_MSG_CHECKING(for Globus/GSI installation directory)
+
+       globus_install_dir=$gsi_path
+
+       if test "x$globus_install_dir" = "xyes" ; then
+               if test -n "$GLOBUS_INSTALL_PATH" ; then
+                       globus_install_dir=$GLOBUS_INSTALL_PATH
+               elif test -n "$GSI_INSTALL_PATH" ; then
+                       globus_install_dir=$GSI_INSTALL_PATH
+               elif test -d /usr/local/globus ; then
+                       globus_install_dir="/usr/local/globus"
+               elif test -d /usr/local/gsi ; then
+                       globus_install_dir="/usr/local/gsi"
+               else
+                       AC_MSG_ERROR(Cannot find Globus/GSI installation directory)
+               fi      
+       fi
+       AC_MSG_RESULT($globus_install_dir)
+
+       # Find GLOBUS/GSI development directory
+       AC_MSG_CHECKING(for Globus/GSI development directory)
+
+       if test -d ${globus_install_dir}/lib ; then
+               # Looks like a flat directory structure from configure/make
+               # and not globus-install or gsi-install
+               globus_dev_dir=$globus_install_dir
+
+       else
+               # Assume a true globus installation with architecture
+               # directories and run globus-development-path to find
+               # the development directory
+
+               # Set GLOBUS_INSTALL_PATH
+               GLOBUS_INSTALL_PATH=$globus_install_dir
+               export GLOBUS_INSTALL_PATH
+
+               dev_path_program=${globus_install_dir}/bin/globus-development-path
+
+               if test ! -x ${dev_path_program} ; then
+                       AC_MSG_ERROR(Cannot find Globus/GSI installation directory: program ${dev_path_program} does not exist or is not executable)
+               fi
+
+               globus_dev_dir=`${dev_path_program}`
+
+               if test -z "$globus_dev_dir" -o "X$globus_dev_dir" = "X<not found>" ; then
+                               AC_MSG_ERROR(Cannot find Globus/GSI development directory)
+               fi
+
+               if test ! -d "$globus_dev_dir" ; then
+                       AC_MSG_ERROR(Cannot find Globus/GSI development directory: $globus_dev_dir does not exist)
+               fi
+       fi
+       AC_MSG_RESULT($globus_dev_dir)
+
+       GSI_LIBS="-lglobus_gss_assist -lglobus_gss -lglobus_gaa -lssl -lcrypto"
+       GSI_LDFLAGS="-L${globus_dev_dir}/lib"
+       GSI_CFLAGS="-I${globus_dev_dir}/include"
+
+       LIBS="$LIBS $GSI_LIBS"
+       LDFLAGS="$LDFLAGS $GSI_LDFLAGS"
+       CFLAGS="$CFLAGS $GSI_CFLAGS"
+# End Globus/GSI section
+fi
+
 # Check whether user wants S/Key support
 SKEY_MSG="no" 
 AC_ARG_WITH(skey,
@@ -1475,6 +1561,31 @@ AC_ARG_WITH(kerberos5,
                         fi
                         AC_CHECK_LIB(resolv, dn_expand, , )
 
+                       AC_CHECK_LIB(gssapi,gss_init_sec_context,
+                               [ AC_DEFINE(GSSAPI)
+                                 K5LIBS="-lgssapi $K5LIBS" ],
+                               [ AC_CHECK_LIB(gssapi_krb5,gss_init_sec_context,
+                                       [ AC_DEFINE(GSSAPI)
+                                         K5LIBS="-lgssapi_krb5 $K5LIBS" ],
+                                       AC_MSG_WARN([Cannot find any suitable gss-api library - build may fail]),
+                                       $K5LIBS)
+                               ],
+                               $K5LIBS)
+                       
+                       AC_CHECK_HEADER(gssapi.h, ,
+                               [ unset ac_cv_header_gssapi_h
+                                 CPPFLAGS="$CPPFLAGS -I${KRB5ROOT}/include/gssapi" 
+                                 AC_CHECK_HEADERS(gssapi.h, ,
+                                       AC_MSG_WARN([Cannot find any suitable gss-api header - build may fail])
+                                 ) 
+                               ]
+                       )
+
+                       oldCPP="$CPPFLAGS"
+                       CPPFLAGS="$CPPFLAGS -I${KRB5ROOT}/include/gssapi"
+                       AC_CHECK_HEADER(gssapi_krb5.h, ,
+                                       [ CPPFLAGS="$oldCPP" ])
+
                         KRB5=yes
                 fi
         ]
diff --git a/openssh/gss-genr.c b/openssh/gss-genr.c
new file mode 100644 (file)
index 0000000..be8208a
--- /dev/null
@@ -0,0 +1,491 @@
+/*
+ * Copyright (c) 2001 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 "ssh.h"
+#include "ssh2.h"
+#include "xmalloc.h"
+#include "buffer.h"
+#include "bufaux.h"
+#include "packet.h"
+#include "compat.h"
+#include <openssl/evp.h>
+#include "cipher.h"
+#include "kex.h"
+#include "log.h"
+
+#include <netdb.h>
+
+#include "ssh-gss.h"
+
+/* Assorted globals for tracking the clients identity once they've
+ * authenticated */
+gss_buffer_desc gssapi_client_name = {0,NULL}; /* Name of our client */
+gss_cred_id_t   gssapi_client_creds = GSS_C_NO_CREDENTIAL; /* Their credentials */
+enum ssh_gss_id gssapi_client_type = GSS_LAST_ENTRY;
+
+/* The mechanism name used in the list below is defined in the internet
+ * draft as the Base 64 encoding of the MD5 hash of the ASN.1 DER encoding 
+ * of the underlying GSSAPI mechanism's OID.
+ *
+ * Also from the draft, before considering adding SPNEGO, bear in mind that
+ * "mechanisms ... MUST NOT use SPNEGO as the underlying GSSAPI mechanism"
+ */
+
+/* These must be in the same order as ssh_gss_id, in ssh-gss.h */
+
+ssh_gssapi_mech supported_mechs[]= {
+#ifdef KRB5
+ /* Official OID - 1.2.850.113554.1.2.2 */
+ {"Se3H81ismmOC3OE+FwYCiQ==","Kerberos",
+       {9, "\x2A\x86\x48\x86\xF7\x12\x01\x02\x02"}},
+#endif
+#ifdef GSI
+ /* gssapi_ssleay 1.3.6.1.4.1.3536.1.1 */
+ {"N3+k7/4wGxHyuP8Yxi4RhA==",
+  "GSI",
+  {9, "\x2B\x06\x01\x04\x01\x9B\x50\x01\x01"}
+ },
+#endif /* GSI */
+ {NULL,NULL,{0,0}}
+};
+
+char gssprefix[]=KEX_GSS_SHA1;
+
+/* Return a list of the gss-group1-sha1-x mechanisms supported by this
+ * program.
+ *
+ * We only support the mechanisms that we've indicated in the list above,
+ * but we check that they're supported by the GSSAPI mechanism on the 
+ * machine. We also check, before including them in the list, that
+ * we have the necesary information in order to carry out the key exchange
+ * (that is, that the user has credentials, the server's creds are accessible,
+ * etc)
+ *
+ * The way that this is done is fairly nasty, as we do a lot of work that
+ * is then thrown away. This should possibly be implemented with a cache
+ * that stores the results (in an expanded Gssctxt structure), which are
+ * then used by the first calls if that key exchange mechanism is chosen.
+ */
+char * 
+ssh_gssapi_mechanisms(int server,char *host) {
+       gss_OID_set     supported;
+       OM_uint32       maj_status, min_status;
+       Buffer          buf;
+       int             i = 0;
+       int             present;
+       char *          mechs;
+       Gssctxt         ctx;    
+       gss_buffer_desc token;          
+
+
+       gss_indicate_mechs(&min_status, &supported);
+       
+       buffer_init(&buf);      
+
+       do {
+               if ((maj_status=gss_test_oid_set_member(&min_status,
+                                                       &supported_mechs[i].oid,
+                                                       supported,
+                                                       &present))) {
+                       present=0;
+               }
+               if (present) {
+                       ssh_gssapi_build_ctx(&ctx);
+                       ssh_gssapi_set_oid(&ctx,&supported_mechs[i].oid);
+                       if (server) {
+                               if (ssh_gssapi_acquire_cred(&ctx)) {
+                                       ssh_gssapi_delete_ctx(&ctx);
+                                       continue;
+                               }
+                       }
+                       else { /* client */
+                               if (ssh_gssapi_import_name(&ctx,host))
+                                       continue;
+                               maj_status=ssh_gssapi_init_ctx(&ctx, 0, 
+                                                              GSS_C_NO_BUFFER,
+                                                              &token,
+                                                              NULL);
+                               ssh_gssapi_delete_ctx(&ctx);
+                               if (GSS_ERROR(maj_status)) {
+                                       continue;
+                               }
+                       }                                
+                               
+                       /* Append gss_group1_sha1_x to our list */
+                       buffer_append(&buf, gssprefix,
+                                     strlen(gssprefix));
+                       buffer_append(&buf, supported_mechs[i].enc_name,
+                                     strlen(supported_mechs[i].enc_name));
+               }
+       } while (supported_mechs[++i].name != 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)
+          return(NULL);
+       else
+          return(mechs);
+}
+
+void ssh_gssapi_supported_oids(gss_OID_set *oidset) {
+       enum ssh_gss_id i =0;
+       OM_uint32 maj_status,min_status;
+       int present;
+       gss_OID_set supported;
+       
+       gss_create_empty_oid_set(&min_status,oidset);
+       gss_indicate_mechs(&min_status, &supported);
+
+       while (supported_mechs[i].name!=NULL) {
+               if ((maj_status=gss_test_oid_set_member(&min_status,
+                                                      &supported_mechs[i].oid,
+                                                      supported,
+                                                      &present))) {
+                       present=0;
+               }
+               if (present) {
+                       gss_add_oid_set_member(&min_status,
+                                              &supported_mechs[i].oid,
+                                              oidset); 
+               }
+               i++;
+       }
+}      
+
+/* Set the contexts OID from a data stream */
+void ssh_gssapi_set_oid_data(Gssctxt *ctx, void *data, size_t len) { 
+  if (ctx->oid != GSS_C_NO_OID) {
+       xfree(ctx->oid->elements);
+       xfree(ctx->oid);
+  }
+  ctx->oid=xmalloc(sizeof(gss_OID_desc));
+  ctx->oid->length=len;
+  ctx->oid->elements=xmalloc(len);
+  memcpy(ctx->oid->elements,data,len);
+}
+
+/* Set the contexts OID */
+void ssh_gssapi_set_oid(Gssctxt *ctx, gss_OID oid) {  
+  ssh_gssapi_set_oid_data(ctx,oid->elements,oid->length);
+}
+
+/* Find out which GSS type (out of the list we define in ssh-gss.h) a
+ * particular connection is using 
+ */
+enum ssh_gss_id ssh_gssapi_get_ctype(Gssctxt *ctxt) {
+       enum ssh_gss_id i=0;
+       
+       while(supported_mechs[i].name!=NULL &&
+               supported_mechs[i].oid.length != ctxt->oid->length &&
+               (memcmp(supported_mechs[i].oid.elements,
+                      ctxt->oid->elements,ctxt->oid->length) !=0)) {
+          i++;
+       }
+       return(i);
+}
+
+/* Set the GSS context's OID to the oid indicated by the given key exchange
+ * name. */
+int ssh_gssapi_id_kex(Gssctxt *ctx, char *name) {
+  enum ssh_gss_id i=0;
+  
+  if (strncmp(name, gssprefix, strlen(gssprefix)-1) !=0) {
+     return(1);
+  }
+  
+  name+=strlen(gssprefix); /* Move to the start of the MIME string */
+  
+  while (supported_mechs[i].name!=NULL &&
+        strcmp(name,supported_mechs[i].enc_name)!=0) {
+       i++;
+  }
+
+  if (supported_mechs[i].name==NULL)
+     return (1);
+
+  ssh_gssapi_set_oid(ctx,&supported_mechs[i].oid);
+
+  return 0;
+}
+
+
+/* All this effort to report an error ... */
+void
+ssh_gssapi_error(OM_uint32 major_status,OM_uint32 minor_status) {
+       OM_uint32 lmaj, lmin;
+        gss_buffer_desc msg;
+        OM_uint32 ctx;
+        
+        ctx = 0;
+       /* The GSSAPI error */
+        do {
+               lmaj = gss_display_status(&lmin, major_status,
+                                         GSS_C_GSS_CODE,
+                                         GSS_C_NULL_OID,
+                                         &ctx, &msg);
+               if (lmaj == GSS_S_COMPLETE) {
+                       debug((char *)msg.value);
+                       (void) gss_release_buffer(&lmin, &msg);
+               }
+        } while (ctx!=0);         
+
+        /* The mechanism specific error */
+        do {
+               lmaj = gss_display_status(&lmin, minor_status,
+                                         GSS_C_MECH_CODE,
+                                         GSS_C_NULL_OID,
+                                         &ctx, &msg);
+               if (lmaj == GSS_S_COMPLETE) {
+                       debug((char *)msg.value);
+                       (void) gss_release_buffer(&lmin, &msg);
+               }
+        } while (ctx!=0);
+}
+
+/* Initialise our GSSAPI context. We use this opaque structure to contain all
+ * of the data which both the client and server need to persist across
+ * {accept,init}_sec_context calls, so that when we do it from the userauth
+ * stuff life is a little easier
+ */
+void
+ssh_gssapi_build_ctx(Gssctxt *ctx)
+{
+       ctx->context=GSS_C_NO_CONTEXT;
+       ctx->name=GSS_C_NO_NAME;
+       ctx->oid=GSS_C_NO_OID;
+       ctx->creds=GSS_C_NO_CREDENTIAL;
+       ctx->client=GSS_C_NO_NAME;
+       ctx->client_creds=GSS_C_NO_CREDENTIAL;
+}
+
+/* Delete our context, providing it has been built correctly */
+void
+ssh_gssapi_delete_ctx(Gssctxt *ctx)
+{
+       OM_uint32 ms;
+       
+       if (ctx->context != GSS_C_NO_CONTEXT) 
+               gss_delete_sec_context(&ms,&ctx->context,GSS_C_NO_BUFFER);
+       if (ctx->name != GSS_C_NO_NAME)
+               gss_release_name(&ms,&ctx->name);
+       if (ctx->oid != GSS_C_NO_OID) {
+               xfree(ctx->oid->elements);
+               xfree(ctx->oid);
+               ctx->oid = GSS_C_NO_OID;
+       }
+       if (ctx->creds != GSS_C_NO_CREDENTIAL)
+               gss_release_cred(&ms,&ctx->creds);
+       if (ctx->client != GSS_C_NO_NAME)
+               gss_release_name(&ms,&ctx->client);     
+       if (ctx->client_creds != GSS_C_NO_CREDENTIAL)
+               gss_release_cred(&ms,&ctx->client_creds); 
+}
+
+/* Wrapper to init_sec_context 
+ * Requires that the context contains:
+ *     oid
+ *     server name (from ssh_gssapi_import_name)
+ */
+OM_uint32 
+ssh_gssapi_init_ctx(Gssctxt *ctx, int deleg_creds, gss_buffer_desc *recv_tok,
+                           gss_buffer_desc* send_tok, OM_uint32 *flags) 
+{
+       OM_uint32 maj_status, min_status;
+       int deleg_flag = 0;
+       
+       if (deleg_creds) {
+               deleg_flag=GSS_C_DELEG_FLAG;
+               debug("Delegating credentials");
+       }
+               
+       maj_status=gss_init_sec_context(&min_status,
+                                       GSS_C_NO_CREDENTIAL, /* def. cred */
+                                       &ctx->context,
+                                       ctx->name,
+                                       ctx->oid,
+                                       GSS_C_MUTUAL_FLAG |
+                                       GSS_C_INTEG_FLAG |
+                                       deleg_flag,
+                                       0, /* default lifetime */
+                                       NULL, /* no channel bindings */
+                                       recv_tok,
+                                       NULL,
+                                       send_tok,
+                                       flags,
+                                       NULL);
+       ctx->status=maj_status;
+       if (GSS_ERROR(maj_status)) {
+               ssh_gssapi_error(maj_status,min_status);
+       }
+       return(maj_status);
+}
+
+/* Wrapper arround accept_sec_context
+ * Requires that the context contains:
+ *    oid              
+ *    credentials      (from ssh_gssapi_acquire_cred)
+ */
+OM_uint32 ssh_gssapi_accept_ctx(Gssctxt *ctx,gss_buffer_desc *recv_tok,
+                               gss_buffer_desc *send_tok, OM_uint32 *flags) 
+{
+       OM_uint32 maj_status, min_status;
+       gss_OID mech;
+       
+       maj_status=gss_accept_sec_context(&min_status,
+                                         &ctx->context,
+                                         ctx->creds,
+                                         recv_tok,
+                                         GSS_C_NO_CHANNEL_BINDINGS,
+                                         &ctx->client,
+                                         &mech,
+                                         send_tok,
+                                         flags,
+                                         NULL,
+                                         &ctx->client_creds);
+       if (GSS_ERROR(maj_status)) {
+               ssh_gssapi_error(maj_status,min_status);
+       }
+       
+       if (ctx->client_creds) {
+               debug("Received some client credentials");
+       } else {
+               debug("Got no client credentials");
+       }
+
+       /* FIXME: We should check that the mechanism thats being used is
+        * the one that we asked for (in ctx->oid) */
+
+       ctx->status=maj_status;
+       
+       return(maj_status);
+}
+
+/* Create a service name for the given host */
+OM_uint32
+ssh_gssapi_import_name(Gssctxt *ctx,char *host) {
+       gss_buffer_desc gssbuf;
+       OM_uint32 maj_status, min_status;
+       struct hostent *hostinfo = NULL;
+       char *xhost;
+       
+       /* Make a copy of the host name, in case it was returned by a
+        * previous call to gethostbyname(). */ 
+       xhost = xstrdup(host);
+
+       /* Make sure we have the FQDN. Some GSSAPI implementations don't do
+        * this for us themselves */
+       
+       hostinfo = gethostbyname(xhost);
+       
+       if ((hostinfo == NULL) || (hostinfo->h_name == NULL)) {
+               debug("Unable to get FQDN for \"%s\"", xhost);
+       } else {
+               host = hostinfo->h_name;
+       }
+       xfree(xhost);
+               
+        gssbuf.length = sizeof("host@")+strlen(host);
+
+        gssbuf.value = xmalloc(gssbuf.length);
+        if (gssbuf.value == NULL) {
+               return(-1);
+        }
+        snprintf(gssbuf.value,gssbuf.length,"host@%s",host);
+        if ((maj_status=gss_import_name(&min_status,
+                                       &gssbuf,
+                                        GSS_C_NT_HOSTBASED_SERVICE,
+                                        &ctx->name))) {
+               ssh_gssapi_error(maj_status,min_status);
+       }
+       
+       xfree(gssbuf.value);
+       return(maj_status);
+}
+
+/* Acquire credentials for a server running on the current host.
+ * Requires that the context structure contains a valid OID
+ */      
+OM_uint32
+ssh_gssapi_acquire_cred(Gssctxt *ctx) {
+       OM_uint32 maj_status, min_status;
+       char lname[MAXHOSTNAMELEN];
+       gss_OID_set oidset;
+       
+       gss_create_empty_oid_set(&min_status,&oidset);
+       gss_add_oid_set_member(&min_status,ctx->oid,&oidset);
+       
+        if (gethostname(lname, MAXHOSTNAMELEN)) {
+                return(-1);
+        }
+
+       if ((maj_status=ssh_gssapi_import_name(ctx,lname))) {
+               return(maj_status);
+       }
+       if ((maj_status=gss_acquire_cred(&min_status,
+                                   ctx->name,
+                                   0,
+                                   oidset,
+                                   GSS_C_ACCEPT,
+                                   &ctx->creds,
+                                   NULL,
+                                   NULL))) {
+               ssh_gssapi_error(maj_status,min_status);
+       }
+                               
+       gss_release_oid_set(&min_status, &oidset);
+       return(maj_status);
+}
+
+/* Extract the client details from a given context. This can only reliably
+ * be called once for a context */
+
+OM_uint32 
+ssh_gssapi_getclient(Gssctxt *ctx, enum ssh_gss_id *type,
+                    gss_buffer_desc *name, gss_cred_id_t *creds) {
+
+       OM_uint32 maj_status,min_status;
+       
+       *type=ssh_gssapi_get_ctype(ctx);
+       if ((maj_status=gss_display_name(&min_status,ctx->client,name,NULL))) {
+               ssh_gssapi_error(maj_status,min_status);
+       }
+       
+       /* This is icky. There appears to be no way to copy this structure,
+        * rather than the pointer to it, so we simply copy the pointer and
+        * mark the originator as empty so we don't destroy it. 
+        */
+       *creds=ctx->client_creds;
+       ctx->client_creds=GSS_C_NO_CREDENTIAL;
+       return(maj_status);
+}
+       
+#endif /* GSSAPI */
diff --git a/openssh/gss-serv.c b/openssh/gss-serv.c
new file mode 100644 (file)
index 0000000..762c210
--- /dev/null
@@ -0,0 +1,586 @@
+/*
+ * Copyright (c) 2001 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 "ssh.h"
+#include "ssh2.h"
+#include "xmalloc.h"
+#include "buffer.h"
+#include "bufaux.h"
+#include "packet.h"
+#include "compat.h"
+#include <openssl/evp.h>
+#include "cipher.h"
+#include "kex.h"
+#include "auth.h"
+#include "log.h"
+#include "session.h"
+#include "dispatch.h"
+#include "servconf.h"
+
+#include "ssh-gss.h"
+
+extern ServerOptions options;
+extern u_char *session_id2;
+extern int session_id2_len;
+
+
+typedef struct ssh_gssapi_cred_cache {
+       char *filename;
+       char *envvar;
+       char *envval;
+       void *data;
+} ssh_gssapi_cred_cache;
+
+static struct ssh_gssapi_cred_cache gssapi_cred_store = {NULL,NULL,NULL};
+
+#ifdef KRB5
+
+#ifdef HEIMDAL
+#include <krb5.h>
+#else
+#include <gssapi_krb5.h>
+#define krb5_get_err_text(context,code) error_message(code)
+#endif
+
+static krb5_context krb_context = NULL;
+
+/* Initialise the krb5 library, so we can use it for those bits that
+ * GSSAPI won't do */
+
+int ssh_gssapi_krb5_init() {
+       krb5_error_code problem;
+       
+       if (krb_context !=NULL)
+               return 1;
+               
+       problem = krb5_init_context(&krb_context);
+       if (problem) {
+               log("Cannot initialize krb5 context");
+               return 0;
+       }
+       krb5_init_ets(krb_context);
+
+       return 1;       
+}                      
+
+/* Check if this user is OK to login. This only works with krb5 - other 
+ * GSSAPI mechanisms will need their own.
+ * Returns true if the user is OK to log in, otherwise returns 0
+ */
+
+int
+ssh_gssapi_krb5_userok(char *name) {
+       krb5_principal princ;
+       int retval;
+
+       if (ssh_gssapi_krb5_init() == 0)
+               return 0;
+               
+       if ((retval=krb5_parse_name(krb_context, gssapi_client_name.value, 
+                                   &princ))) {
+               log("krb5_parse_name(): %.100s", 
+                       krb5_get_err_text(krb_context,retval));
+               return 0;
+       }
+       if (krb5_kuserok(krb_context, princ, name)) {
+               retval = 1;
+               log("Authorized to %s, krb5 principal %s (krb5_kuserok)",name,
+                   (char *)gssapi_client_name.value);
+       }
+       else
+               retval = 0;
+       
+       krb5_free_principal(krb_context, princ);
+       return retval;
+}
+       
+/* Make sure that this is called _after_ we've setuid to the user */
+
+/* This writes out any forwarded credentials. Its specific to the Kerberos
+ * GSSAPI mechanism
+ *
+ * We assume that our caller has made sure that the user has selected
+ * delegated credentials, and that the client_creds structure is correctly
+ * populated.
+ */
+
+void
+ssh_gssapi_krb5_storecreds() {
+       krb5_ccache ccache;
+       krb5_error_code problem;
+       krb5_principal princ;
+       char ccname[35];
+       static char name[40];
+       int tmpfd;
+       OM_uint32 maj_status,min_status;
+
+
+       if (gssapi_client_creds==NULL) {
+               debug("No credentials stored"); 
+               return;
+       }
+               
+       if (ssh_gssapi_krb5_init() == 0)
+               return;
+
+       if (options.gss_use_session_ccache) {
+               snprintf(ccname,sizeof(ccname),"/tmp/krb5cc_%d_XXXXXX",geteuid());
+       
+               if ((tmpfd = mkstemp(ccname))==-1) {
+                       log("mkstemp(): %.100s", strerror(errno));
+                       return;
+               }
+               if (fchmod(tmpfd, S_IRUSR | S_IWUSR) == -1) {
+                       log("fchmod(): %.100s", strerror(errno));
+                       close(tmpfd);
+                       return;
+               }
+        } else {
+               snprintf(ccname,sizeof(ccname),"/tmp/krb5cc_%d",geteuid());
+               tmpfd = open(ccname, O_TRUNC | O_CREAT, S_IRUSR | S_IWUSR);
+               if (tmpfd == -1) {
+                       log("open(): %.100s", strerror(errno));
+                       return;
+               }
+        }
+
+               close(tmpfd);
+        snprintf(name, sizeof(name), "FILE:%s",ccname);
+        if ((problem = krb5_cc_resolve(krb_context, name, &ccache))) {
+                log("krb5_cc_default(): %.100s", 
+                       krb5_get_err_text(krb_context,problem));
+                return;
+        }
+
+       if ((problem = krb5_parse_name(krb_context, gssapi_client_name.value, 
+                                      &princ))) {
+               log("krb5_parse_name(): %.100s", 
+                       krb5_get_err_text(krb_context,problem));
+               krb5_cc_destroy(krb_context,ccache);
+               return;
+       }
+       
+       if ((problem = krb5_cc_initialize(krb_context, ccache, princ))) {
+               log("krb5_cc_initialize(): %.100s", 
+                       krb5_get_err_text(krb_context,problem));
+               krb5_free_principal(krb_context,princ);
+               krb5_cc_destroy(krb_context,ccache);
+               return;
+       }
+       
+       krb5_free_principal(krb_context,princ);
+
+       #ifdef HEIMDAL
+       if ((problem = krb5_cc_copy_cache(krb_context, 
+                                          gssapi_client_creds->ccache,
+                                          ccache))) {
+               log("krb5_cc_copy_cache(): %.100s", 
+                       krb5_get_err_text(krb_context,problem));
+               krb5_cc_destroy(krb_context,ccache);
+               return;
+       }
+       #else
+       if ((maj_status = gss_krb5_copy_ccache(&min_status, 
+                                              gssapi_client_creds, 
+                                              ccache))) {
+               log("gss_krb5_copy_ccache() failed");
+               ssh_gssapi_error(maj_status,min_status);
+               krb5_cc_destroy(krb_context,ccache);
+               return;
+       }
+       #endif
+       
+       krb5_cc_close(krb_context,ccache);
+
+
+#ifdef USE_PAM
+       do_pam_putenv("KRB5CCNAME",name);
+#endif
+
+       gssapi_cred_store.filename=strdup(ccname);
+       gssapi_cred_store.envvar="KRB5CCNAME";
+       gssapi_cred_store.envval=strdup(name);
+
+       return;
+}
+
+#endif /* KRB5 */
+
+#ifdef GSI
+#include <globus_gss_assist.h>
+
+/*
+ * Check if this user is OK to login under GSI. User has been authenticated
+ * as identity in global 'client_name.value' and is trying to log in as passed
+ * username in 'name'.
+ *
+ * Returns non-zero if user is authorized, 0 otherwise.
+ */
+int
+ssh_gssapi_gsi_userok(char *name)
+{
+    int authorized = 0;
+    
+    /* This returns 0 on success */
+    authorized = (globus_gss_assist_userok(gssapi_client_name.value,
+                                          name) == 0);
+    
+    debug("GSI user %s is%s authorized as target user %s",
+         (char *) gssapi_client_name.value,
+         (authorized ? "" : " not"),
+         name);
+    
+    return authorized;
+}
+
+/*
+ * Handle setting up child environment for GSI.
+ *
+ * Make sure that this is called _after_ we've setuid to the user.
+ */
+void
+ssh_gssapi_gsi_storecreds()
+{
+       OM_uint32       major_status;
+       OM_uint32       minor_status;
+       
+       
+       if (gssapi_client_creds != NULL)
+       {
+               char *creds_env = NULL;
+
+               /*
+                * This is the current hack with the GSI gssapi library to
+                * export credentials to disk.
+                */
+
+               debug("Exporting delegated credentials");
+               
+               minor_status = 0xdee0;  /* Magic value */
+               major_status =
+                       gss_inquire_cred(&minor_status,
+                                        gssapi_client_creds,
+                                        (gss_name_t *) &creds_env,
+                                        NULL,
+                                        NULL,
+                                        NULL);
+
+               if ((major_status == GSS_S_COMPLETE) &&
+                   (minor_status == 0xdee1) &&
+                   (creds_env != NULL))
+               {
+                       char            *value;
+                               
+                       /*
+                        * String is of the form:
+                        * X509_USER_DELEG_PROXY=filename
+                        * so we parse out the filename
+                        * and then set X509_USER_PROXY
+                        * to point at it.
+                        */
+                       value = strchr(creds_env, '=');
+                       
+                       if (value != NULL)
+                       {
+                               *value = '\0';
+                               value++;
+#ifdef USE_PAM
+                               do_pam_putenv("X509_USER_PROXY",value);
+#endif
+                               gssapi_cred_store.filename=NULL;
+                               gssapi_cred_store.envvar="X509_USER_PROXY";
+                               gssapi_cred_store.envval=strdup(value);
+
+                               return;
+                       }
+                       else
+                       {
+                               log("Failed to parse delegated credentials string '%s'",
+                                   creds_env);
+                       }
+               }
+               else
+               {
+                       log("Failed to export delegated credentials (error %ld)",
+                           major_status);
+               }
+       }       
+}
+
+#endif /* GSI */
+
+void
+ssh_gssapi_cleanup_creds(void *ignored)
+{
+       if (gssapi_cred_store.filename!=NULL) {
+               /* Unlink probably isn't sufficient */
+               debug("removing gssapi cred file\"%s\"",gssapi_cred_store.filename);
+               unlink(gssapi_cred_store.filename);
+       }
+}
+
+void 
+ssh_gssapi_storecreds()
+{
+       switch (gssapi_client_type) {
+#ifdef KRB5
+       case GSS_KERBEROS:
+               ssh_gssapi_krb5_storecreds();
+               break;
+#endif
+#ifdef GSI
+       case GSS_GSI:
+               ssh_gssapi_gsi_storecreds();
+               break;
+#endif /* GSI */
+       case GSS_LAST_ENTRY:
+               /* GSSAPI not used in this authentication */
+               debug("No GSSAPI credentials stored");
+               break;
+       default:
+               log("ssh_gssapi_do_child: Unknown mechanism");
+       
+       }
+       
+       if (options.gss_cleanup_creds) {
+               fatal_add_cleanup(ssh_gssapi_cleanup_creds, NULL);
+       }
+
+}
+
+/* This allows GSSAPI methods to do things to the childs environment based
+ * on the passed authentication process and credentials.
+ *
+ * Question: If we didn't use userauth_external for some reason, should we
+ * still delegate credentials?
+ */
+void 
+ssh_gssapi_do_child(char ***envp, u_int *envsizep) 
+{
+
+       if (gssapi_cred_store.envvar!=NULL && 
+           gssapi_cred_store.envval!=NULL) {
+           
+               debug("Setting %s to %s", gssapi_cred_store.envvar,
+                                         gssapi_cred_store.envval);                              
+               child_set_env(envp, envsizep, gssapi_cred_store.envvar, 
+                                             gssapi_cred_store.envval);
+       }
+
+       switch(gssapi_client_type) {
+#ifdef KRB5
+       case GSS_KERBEROS: break;
+#endif
+#ifdef GSI
+       case GSS_GSI: break;
+#endif
+       case GSS_LAST_ENTRY:
+               debug("No GSSAPI credentials stored");
+               
+       default:
+               log("ssh_gssapi_do_child: Unknown mechanism");
+       }
+}
+
+int
+ssh_gssapi_userok(char *user)
+{
+       if (gssapi_client_name.length==0 || 
+           gssapi_client_name.value==NULL) {
+               debug("No suitable client data");
+               return 0;
+       }
+       switch (gssapi_client_type) {
+#ifdef KRB5
+       case GSS_KERBEROS:
+               return(ssh_gssapi_krb5_userok(user));
+               break; /* Not reached */
+#endif
+#ifdef GSI
+       case GSS_GSI:
+               return(ssh_gssapi_gsi_userok(user));
+               break; /* Not reached */
+#endif /* GSI */
+       case GSS_LAST_ENTRY:
+               debug("Client not GSSAPI");
+               break;
+       default:
+               debug("Unknown client authentication type");
+       }
+       return(0);
+}
+
+int
+userauth_external(Authctxt *authctxt)
+{
+       packet_done();
+
+       return(ssh_gssapi_userok(authctxt->user));
+}
+
+void input_gssapi_token(int type, int plen, void *ctxt);
+void input_gssapi_exchange_complete(int type, int plen, void *ctxt);
+
+/* We only support those mechanisms that we know about (ie ones that we know
+ * how to check local user kuserok and the like
+ */
+int
+userauth_gssapi(Authctxt *authctxt)
+{
+       gss_OID_desc    oid= {0,NULL};
+       Gssctxt         *ctxt;
+       int             mechs;
+       gss_OID_set     supported;
+       int             present;
+       OM_uint32       ms;
+       
+       if (!authctxt->valid || authctxt->user == NULL)
+               return 0;
+       mechs=packet_get_int();
+       if (mechs==0) {
+               debug("Mechanism negotiation is not supported");
+               return 0;
+       }
+
+       ssh_gssapi_supported_oids(&supported);
+       do {
+               if (oid.elements)
+                       xfree(oid.elements);
+               oid.elements = packet_get_string(&oid.length);
+               gss_test_oid_set_member(&ms, &oid, supported, &present);
+               mechs--;
+       } while (mechs>0 && !present);
+       
+       if (!present) {
+               xfree(oid.elements);
+               return(0);
+       }
+       
+       ctxt=xmalloc(sizeof(Gssctxt));
+       authctxt->methoddata=(void *)ctxt;
+       
+       ssh_gssapi_build_ctx(ctxt);
+       ssh_gssapi_set_oid(ctxt,&oid);
+
+       if (ssh_gssapi_acquire_cred(ctxt))
+               return 0;
+
+       /* Send SSH_MSG_USERAUTH_GSSAPI_RESPONSE */
+
+       packet_start(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE);
+       packet_put_string(oid.elements,oid.length);
+       packet_send();
+       packet_write_wait();
+       xfree(oid.elements);
+               
+       dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, 
+                    &input_gssapi_token);
+       authctxt->postponed = 1;
+       
+       return 0;
+}
+
+void
+input_gssapi_token(int type, int plen, void *ctxt)
+{
+       Authctxt *authctxt = ctxt;
+       Gssctxt *gssctxt;
+       gss_buffer_desc send_tok,recv_tok;
+       OM_uint32 maj_status, min_status;
+       
+       if (authctxt == NULL || authctxt->methoddata == NULL)
+               fatal("No authentication or GSSAPI context");
+               
+       gssctxt=authctxt->methoddata;
+
+       recv_tok.value=packet_get_string(&recv_tok.length);
+       
+       maj_status=ssh_gssapi_accept_ctx(gssctxt, &recv_tok, &send_tok, NULL);
+       packet_done();
+       
+       if (GSS_ERROR(maj_status)) {
+               /* Failure <sniff> */
+               authctxt->postponed = 0;
+               dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
+               userauth_finish(authctxt, 0, "gssapi");
+       }
+                       
+       if (send_tok.length != 0) {
+               /* Send a packet back to the client */
+               packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
+                packet_put_string(send_tok.value,send_tok.length);
+                packet_send();
+                packet_write_wait();
+                gss_release_buffer(&min_status, &send_tok);                                     
+       }
+       
+       if (maj_status == GSS_S_COMPLETE) {
+               dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN,NULL);
+               dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE,
+                            &input_gssapi_exchange_complete);
+       }
+}
+
+/* This is called when the client thinks we've completed authentication.
+ * It should only be enabled in the dispatch handler by the function above,
+ * which only enables it once the GSSAPI exchange is complete.
+ */
+void
+input_gssapi_exchange_complete(int type, int plen, void *ctxt)
+{
+       Authctxt *authctxt = ctxt;
+       Gssctxt *gssctxt;
+       int authenticated;
+       
+       if (authctxt == NULL || authctxt->methoddata == NULL)
+               fatal("No authentication or GSSAPI context");
+               
+       gssctxt=authctxt->methoddata;
+
+       /* This should never happen, but better safe than sorry. */
+       if (gssctxt->status != GSS_S_COMPLETE) {
+               packet_disconnect("Context negotiation is not complete");
+       }
+
+       if (ssh_gssapi_getclient(gssctxt,&gssapi_client_type,
+                                &gssapi_client_name,
+                                &gssapi_client_creds)) {
+               fatal("Couldn't convert client name");
+       }
+                                               
+        authenticated = ssh_gssapi_userok(authctxt->user);
+
+       authctxt->postponed = 0;
+       dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
+       dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
+       userauth_finish(authctxt, authenticated, "gssapi");
+}
+
+#endif /* GSSAPI */
index 1a412ce0fcab2c98104d184d046b7b3c852a7880..3a4478bd57f27d97e8a3f2ca4dc2d9ceeb7a74ce 100644 (file)
@@ -41,6 +41,10 @@ RCSID("$OpenBSD: kex.c,v 1.36 2001/06/25 08:25:37 markus Exp $");
 #include "match.h"
 #include "dispatch.h"
 
+#ifdef GSSAPI
+#include "ssh-gss.h"
+#endif
+
 #define KEX_COOKIE_LEN 16
 
 /* prototype */
@@ -226,6 +230,11 @@ kex_kexinit_finish(Kex *kex)
        case DH_GEX_SHA1:
                kexgex(kex);
                break;
+#ifdef GSSAPI
+       case GSS_GRP1_SHA1:
+               kexgss(kex);
+               break;
+#endif
        default:
                fatal("Unsupported key exchange %d", kex->kex_type);
        }
@@ -280,11 +289,15 @@ choose_kex(Kex *k, char *client, char *server)
 {
        k->name = match_list(client, server, NULL);
        if (k->name == NULL)
-               fatal("no kex alg");
+               fatal("No key exchange algorithm");
        if (strcmp(k->name, KEX_DH1) == 0) {
                k->kex_type = DH_GRP1_SHA1;
        } else if (strcmp(k->name, KEX_DHGEX) == 0) {
                k->kex_type = DH_GEX_SHA1;
+#ifdef GSSAPI
+       } else if (strncmp(k->name, KEX_GSS_SHA1, sizeof(KEX_GSS_SHA1)-1) == 0) {
+               k->kex_type = GSS_GRP1_SHA1;
+#endif
        } else
                fatal("bad kex alg %s", k->name);
 }
index fe339211af78417397a9707b853ecabf18b48ddb..0fde811788a05b7356f63459c1affb41f8e33b1d 100644 (file)
@@ -56,7 +56,8 @@ enum kex_modes {
 
 enum kex_exchange {
        DH_GRP1_SHA1,
-       DH_GEX_SHA1
+       DH_GEX_SHA1,
+       GSS_GRP1_SHA1
 };
 
 #define KEX_INIT_SENT  0x0001
@@ -92,6 +93,11 @@ struct Newkeys {
        Mac     mac;
        Comp    comp;
 };
+
+struct KexOptions {
+       int     gss_deleg_creds;
+};
+
 struct Kex {
        u_char  *session_id;
        int     session_id_len;
@@ -105,10 +111,12 @@ struct Kex {
        Buffer  peer;
        int     done;
        int     flags;
+       char    *host;
        char    *client_version_string;
        char    *server_version_string;
        int     (*verify_host_key)(Key *);
        Key     *(*load_host_key)(int);
+       struct  KexOptions options;
 };
 
 Kex    *kex_setup(char *[PROPOSAL_MAX]);
diff --git a/openssh/kexgss.c b/openssh/kexgss.c
new file mode 100644 (file)
index 0000000..1eb11ff
--- /dev/null
@@ -0,0 +1,450 @@
+/*
+ * Copyright (c) 2001 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 <openssl/crypto.h>
+#include <openssl/bn.h>
+
+#include "xmalloc.h"
+#include "buffer.h"
+#include "bufaux.h"
+#include "kex.h"
+#include "log.h"
+#include "packet.h"
+#include "dh.h"
+#include "ssh2.h"
+#include "ssh-gss.h"
+
+/* This is now the same as the DH hash ... */
+
+u_char *
+kex_gssapi_hash(
+    char *client_version_string,
+    char *server_version_string,
+    char *ckexinit, int ckexinitlen,
+    char *skexinit, int skexinitlen,
+    u_char *serverhostkeyblob, int sbloblen,
+    BIGNUM *client_dh_pub,
+    BIGNUM *server_dh_pub,
+    BIGNUM *shared_secret)
+{
+       Buffer b;
+       static u_char digest[EVP_MAX_MD_SIZE];
+       EVP_MD *evp_md = EVP_sha1();
+       EVP_MD_CTX md;
+
+       buffer_init(&b);
+       buffer_put_string(&b, client_version_string, strlen(client_version_string));
+       buffer_put_string(&b, server_version_string, strlen(server_version_string));
+
+       /* kexinit messages: fake header: len+SSH2_MSG_KEXINIT */
+       buffer_put_int(&b, ckexinitlen+1);
+       buffer_put_char(&b, SSH2_MSG_KEXINIT);
+       buffer_append(&b, ckexinit, ckexinitlen);
+       buffer_put_int(&b, skexinitlen+1);
+       buffer_put_char(&b, SSH2_MSG_KEXINIT);
+       buffer_append(&b, skexinit, skexinitlen);
+
+       buffer_put_string(&b, serverhostkeyblob, sbloblen);
+       buffer_put_bignum2(&b, client_dh_pub);
+       buffer_put_bignum2(&b, server_dh_pub);
+       buffer_put_bignum2(&b, shared_secret);
+
+#ifdef DEBUG_KEX
+       buffer_dump(&b);
+#endif
+       EVP_DigestInit(&md, evp_md);
+       EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b));
+       EVP_DigestFinal(&md, digest, NULL);
+
+       buffer_free(&b);
+
+#ifdef DEBUG_KEX
+       dump_digest("hash", digest, evp_md->md_size);
+#endif
+       return digest;
+}
+
+void
+kexgss_client(Kex *kex)
+{
+       gss_buffer_desc gssbuf,send_tok,recv_tok, msg_tok, *token_ptr;
+       Gssctxt ctxt;
+       OM_uint32 maj_status, min_status, ret_flags;
+       int plen,dlen;
+       unsigned int klen, kout;
+       DH *dh; 
+       BIGNUM *dh_server_pub = 0;
+       BIGNUM *shared_secret = 0;      
+       unsigned char *kbuf;
+       unsigned char *hash;
+       unsigned char *serverhostkey;
+       int type = 0;
+       int first = 1;
+       int slen = 0;
+       
+       /* Initialise our GSSAPI world */
+       ssh_gssapi_build_ctx(&ctxt);
+       if (ssh_gssapi_id_kex(&ctxt,kex->name)) {
+               fatal("Couldn't identify host exchange");
+       }
+       if (ssh_gssapi_import_name(&ctxt,kex->host)) {
+               fatal("Couldn't import hostname ");
+       }
+       
+       /* This code should match that in ssh_dh1_client */
+               
+       /* Step 1 - e is dh->pub_key */
+       dh = dh_new_group1();
+       dh_gen_key(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->options.gss_deleg_creds,
+                                              token_ptr,&send_tok,
+                                              &ret_flags);
+
+               if (GSS_ERROR(maj_status)) {
+                       fatal("gss_init_context failed");
+               } 
+
+               /* If we've got an old receive buffer get rid of it */
+               if (token_ptr != GSS_C_NO_BUFFER)
+                       (void) gss_release_buffer(&min_status, &recv_tok);
+       
+               
+               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(dh->pub_key);
+                               first=0;
+                       } else {
+                               packet_start(SSH2_MSG_KEXGSS_CONTINUE);
+                               packet_put_string(send_tok.value,
+                                                 send_tok.length);
+                       }
+                       packet_send();
+                       packet_write_wait();
+
+                       
+                       /* If we've sent them data, they'd better be polite
+                        * and reply. */
+               
+                       type = packet_read(&plen);
+                       switch (type) {
+                       case SSH2_MSG_KEXGSS_HOSTKEY:
+                               debug("Received KEXGSS_HOSTKEY");
+                               serverhostkey=packet_get_string(&slen);
+                               break;
+                       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(&recv_tok.length);
+                               break;
+                       case SSH2_MSG_KEXGSS_COMPLETE:
+                               debug("Received GSSAPI_COMPLETE");
+                               packet_get_bignum2(dh_server_pub, &dlen);
+                               msg_tok.value=
+                                   packet_get_string(&msg_tok.length);
+
+                               /* Is there a token included? */
+                               if (packet_get_char()) {
+                                       recv_tok.value=
+                                           packet_get_string(&recv_tok.length);
+                                       /* 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;
+                       default:
+                               packet_disconnect("Protocol error: didn't expect packet type %d",
+                               type);
+                       }
+                       token_ptr=&recv_tok;
+               }
+
+       } 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(dh, dh_server_pub))
+                        packet_disconnect("bad server public DH value");
+                        
+        /* compute K=f^x mod p */
+        klen = DH_size(dh);
+        kbuf = xmalloc(klen);
+        kout = DH_compute_key(kbuf, dh_server_pub, dh);
+        
+        shared_secret = BN_new();
+        BN_bin2bn(kbuf,kout, shared_secret);
+        memset(kbuf, 0, klen);
+        xfree(kbuf);
+        
+        hash = kex_gssapi_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, slen, /* server host key */
+            dh->pub_key,       /* e */
+            dh_server_pub,     /* f */
+            shared_secret      /* K */
+        );
+        
+        gssbuf.value=hash;
+        gssbuf.length=20;
+        
+        /* Verify that H matches the token we just got. */
+                if ((maj_status = gss_verify_mic(&min_status,
+                                        ctxt.context,
+                                        &gssbuf,
+                                        &msg_tok,
+                                        NULL))) {
+
+               packet_disconnect("Hash's MIC didn't verify");
+       }       
+        
+        DH_free(dh);
+               ssh_gssapi_delete_ctx(&ctxt);
+        /* save session id */
+        if (kex->session_id == NULL) {
+               kex->session_id_len = 20;
+               kex->session_id = xmalloc(kex->session_id_len);
+               memcpy(kex->session_id, hash, kex->session_id_len);
+        }
+        
+       kex_derive_keys(kex, hash, shared_secret);
+       BN_clear_free(shared_secret);
+        kex_finish(kex);
+}
+
+
+
+
+void
+kexgss_server(Kex *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,send_tok,recv_tok,msg_tok;
+       Gssctxt ctxt;
+        int plen;
+        int dlen=0;
+        unsigned int klen, kout;
+        unsigned char *kbuf;
+        unsigned char *hash;
+        DH *dh;
+        BIGNUM *shared_secret = 0;
+        BIGNUM *dh_client_pub = 0;
+       int type =0;
+       
+       /* Initialise GSSAPI */
+
+       ssh_gssapi_build_ctx(&ctxt);
+        if (ssh_gssapi_id_kex(&ctxt,kex->name))
+               fatal("Unknown gssapi mechanism");
+        if (ssh_gssapi_acquire_cred(&ctxt))
+               fatal("Unable to acquire credentials for the server");
+                                                                                                                                
+       /* Initialise some bignums */
+        dh_client_pub = BN_new();
+        if (dh_client_pub == NULL)
+               fatal("dh_client_pub == NULL");
+
+       do {
+               debug("Wait SSH2_MSG_GSSAPI_INIT");
+               type = packet_read(&plen);
+               switch(type) {
+               case SSH2_MSG_KEXGSS_INIT:
+                       if (dlen!=0) 
+                               fatal("Received KEXGSS_INIT after initialising");
+                       recv_tok.value=packet_get_string(&recv_tok.length);
+                       packet_get_bignum2(dh_client_pub, &dlen);
+                       /* Send SSH_MSG_KEXGSS_HOSTKEY here, if we want */
+                       break;
+               case SSH2_MSG_KEXGSS_CONTINUE:
+                       if (dlen==0)
+                               fatal("Received KEXGSS_CONTINUE without initialising");
+                       recv_tok.value=packet_get_string(&recv_tok.length);
+                       break;
+               default:
+                       packet_disconnect("Protocol error: didn't expect packet type %d",
+                                          type);
+               }
+               maj_status=ssh_gssapi_accept_ctx(&ctxt,&recv_tok, &send_tok,
+                                                &ret_flags);
+
+               gss_release_buffer(&min_status,&recv_tok);
+               
+               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();
+                       packet_write_wait();
+                       gss_release_buffer(&min_status, &send_tok);
+               }
+       } while (maj_status & GSS_S_CONTINUE_NEEDED);
+
+       if (GSS_ERROR(maj_status))
+               fatal("gss_accept_context died");
+       
+       debug("gss_complete");
+       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");
+               
+       
+       dh = dh_new_group1();
+       dh_gen_key(dh, kex->we_need * 8);
+       
+        if (!dh_pub_is_valid(dh, dh_client_pub))
+                packet_disconnect("bad client public DH value");
+
+        klen = DH_size(dh);
+        kbuf = xmalloc(klen); 
+        kout = DH_compute_key(kbuf, dh_client_pub, dh);
+
+       shared_secret = BN_new();
+       BN_bin2bn(kbuf, kout, shared_secret);
+       memset(kbuf, 0, klen);
+       xfree(kbuf);
+       
+        hash = kex_gssapi_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,
+            dh->pub_key,
+            shared_secret
+       );
+       BN_free(dh_client_pub);
+               
+       if (kex->session_id == NULL) {
+               kex->session_id_len = 20;
+               kex->session_id = xmalloc(kex->session_id_len);
+               memcpy(kex->session_id, hash, kex->session_id_len);
+       }
+                               
+       gssbuf.value = hash;
+       gssbuf.length = 20; /* Hashlen appears to always be 20 */
+       
+       if ((maj_status=gss_get_mic(&min_status,
+                              ctxt.context,
+                              GSS_C_QOP_DEFAULT,
+                              &gssbuf,
+                              &msg_tok))) {
+               ssh_gssapi_error(maj_status,min_status);
+               fatal("Couldn't get MIC");
+       }       
+                             
+       packet_start(SSH2_MSG_KEXGSS_COMPLETE);
+       packet_put_bignum2(dh->pub_key);
+       packet_put_string((char *)msg_tok.value,msg_tok.length);
+
+       if (send_tok.length!=0) {
+               packet_put_char(1); /* true */
+               packet_put_string((char *)send_tok.value,send_tok.length);
+       } else {
+               packet_put_char(0); /* false */
+       }
+       packet_send();
+       packet_write_wait();
+
+       /* Store the client name, and the delegated credentials for later
+        * use */
+       if (ssh_gssapi_getclient(&ctxt,&gssapi_client_type, 
+                                      &gssapi_client_name, 
+                                      &gssapi_client_creds)) {
+               fatal("Couldn't convert client name");
+       }
+       
+       gss_release_buffer(&min_status, &send_tok);     
+       ssh_gssapi_delete_ctx(&ctxt);
+       DH_free(dh);
+
+       kex_derive_keys(kex, hash, shared_secret);
+       BN_clear_free(shared_secret);
+       kex_finish(kex);
+}
+
+void 
+kexgss(Kex *kex)
+{
+       if (kex->server)
+               kexgss_server(kex);
+       else
+               kexgss_client(kex);
+}
+
+#endif /* GSSAPI */
index 57df5b93aef7ae9015572cf93dcb89eaf0e1d29b..db3a689179cf1c4d0646964c921683173c2b2c0e 100644 (file)
@@ -625,6 +625,8 @@ key_type_from_name(char *name)
                return KEY_RSA;
        } else if (strcmp(name, "ssh-dss") == 0){
                return KEY_DSA;
+       } else if (strcmp(name, "null") == 0){
+               return KEY_NULL;
        }
        debug2("key_type_from_name: unknown key type '%s'", name);
        return KEY_UNSPEC;
index 00eebb7f1a10b87eb2faf1ff3d3588af7d13bf53..6a878d823f9ae6bec1c98ac8c5ebc42e21a96917 100644 (file)
@@ -34,6 +34,7 @@ enum types {
        KEY_RSA1,
        KEY_RSA,
        KEY_DSA,
+       KEY_NULL,
        KEY_UNSPEC
 };
 enum fp_type {
diff --git a/openssh/makegssname.pl b/openssh/makegssname.pl
new file mode 100644 (file)
index 0000000..b91f30b
--- /dev/null
@@ -0,0 +1,46 @@
+#!/usr/bin/perl
+
+use Convert::ASN1 qw(:tag);
+use Digest::MD5 qw(md5);
+use MIME::Base64;
+$oid=shift;
+$encoded=encode_object_id($oid);
+
+@entries=unpack("C*",$encoded);
+shift @entries; # Get rid of the NULL
+
+print "DER representation: ";
+foreach $entry (@entries) {
+  print "\\x";
+  printf "%02X",$entry;
+}
+print "\n";
+
+$digest = md5($encoded);
+# We only want the first 10 characters;
+# Conversations with the authors suggest that we want to use all of the
+# characters of the digest.
+#$digest = substr($digest,0,10);
+print "gsskeyex representation: ",encode_base64($digest),"\n";
+
+sub encode_object_id {
+  $string="";
+
+  my @data = ($_[0] =~ /(\d+)/g);
+
+  if(@data < 2) {
+      @data = (0);
+  }
+  else {
+      my $first = $data[1] + ($data[0] * 40);
+      splice(@data,0,2,$first);
+  }
+
+#  my $l = length $string;
+  $string .= pack("cw*", 0, @data);
+#  substr($string,$l,1) = asn_encode_length(length($string) - $l - 1);
+  return $string;
+}
+
+
index 63035b37f9e84c02b4341f02b7e8f5f307dfb76b..1f35670d33739e7e62227d6ccbc324aec81b54da 100644 (file)
@@ -99,6 +99,12 @@ typedef enum {
 #if defined(KRB4) || defined(KRB5)
        oKerberosAuthentication,
 #endif
+#ifdef GSSAPI
+       oGssAuthentication, oGssDelegateCreds,
+#ifdef GSI
+       oGssGlobusDelegateLimitedCreds,
+#endif /* GSI */
+#endif /* GSSAPI */
 #if defined(AFS) || defined(KRB5)
        oKerberosTgtPassing,
 #endif
@@ -144,6 +150,15 @@ static struct {
 #if defined(KRB4) || defined(KRB5)
        { "kerberosauthentication", oKerberosAuthentication },
 #endif
+#ifdef GSSAPI
+       { "gssapiauthentication", oGssAuthentication },
+       { "gssapidelegatecredentials", oGssDelegateCreds },
+#ifdef GSI
+       /* For backwards compatability with old 1.2.27 client code */
+       { "forwardgssapiglobusproxy", oGssDelegateCreds }, /* alias */
+       { "forwardgssapiglobuslimitedproxy", oGssGlobusDelegateLimitedCreds },
+#endif /* GSI */
+#endif /* GSSAPI */
 #if defined(AFS) || defined(KRB5)
        { "kerberostgtpassing", oKerberosTgtPassing },
 #endif
@@ -363,6 +378,23 @@ parse_flag:
                intptr = &options->kerberos_authentication;
                goto parse_flag;
 #endif
+#ifdef GSSAPI
+       case oGssAuthentication:
+               intptr = &options->gss_authentication;
+               goto parse_flag;
+      
+       case oGssDelegateCreds:
+               intptr = &options->gss_deleg_creds;
+               goto parse_flag;
+#ifdef GSI
+       case oGssGlobusDelegateLimitedCreds:
+               intptr = &options->gss_globus_deleg_limited_proxy;
+               goto parse_flag;
+#endif /* GSI */
+
+#endif /* GSSAPI */
+
 #if defined(AFS) || defined(KRB5)
        case oKerberosTgtPassing:
                intptr = &options->kerberos_tgt_passing;
@@ -751,6 +783,14 @@ initialize_options(Options * options)
        options->rsa_authentication = -1;
        options->pubkey_authentication = -1;
        options->challenge_response_authentication = -1;
+#ifdef GSSAPI
+        options->gss_authentication = -1;
+        options->gss_deleg_creds = -1;
+#ifdef GSI
+        options->gss_globus_deleg_limited_proxy = -1;
+#endif /* GSI */
+#endif /* GSSAPI */
+
 #if defined(KRB4) || defined(KRB5)
        options->kerberos_authentication = -1;
 #endif
@@ -831,6 +871,16 @@ fill_default_options(Options * options)
                options->pubkey_authentication = 1;
        if (options->challenge_response_authentication == -1)
                options->challenge_response_authentication = 1;
+#ifdef GSSAPI
+       if (options->gss_authentication == -1)
+               options->gss_authentication = 1;
+       if (options->gss_deleg_creds == -1)
+               options->gss_deleg_creds = 1;
+#ifdef GSI
+       if (options->gss_globus_deleg_limited_proxy == -1)
+               options->gss_globus_deleg_limited_proxy = 0;
+#endif /* GSI */
+#endif /* GSSAPI */
 #if defined(KRB4) || defined(KRB5)
        if (options->kerberos_authentication == -1)
                options->kerberos_authentication = 1;
index 25ffa4668b4f482ff70389e88640a98e84709e42..6a3823b02b78e19d26f8d1fa376c6c0bb08067a8 100644 (file)
@@ -47,6 +47,15 @@ typedef struct {
 #if defined(AFS) || defined(KRB5)
        int     kerberos_tgt_passing;   /* Try Kerberos TGT passing. */
 #endif
+
+#ifdef GSSAPI
+       int     gss_authentication;
+       int     gss_deleg_creds;
+#ifdef GSI
+       int     gss_globus_deleg_limited_proxy;
+#endif /* GSI */
+#endif /* GSSAPI */
+
 #ifdef AFS
        int     afs_token_passing;      /* Try AFS token passing. */
 #endif
index 15877658a244535d0572ad85e7c5908fd751cc47..461da8d370a6871a01f47b4c6d3d1578a6c3c552 100644 (file)
@@ -83,6 +83,12 @@ initialize_server_options(ServerOptions *options)
        options->hostbased_uses_name_from_packet_only = -1;
        options->rsa_authentication = -1;
        options->pubkey_authentication = -1;
+#ifdef GSSAPI
+       options->gss_authentication=-1;
+       options->gss_keyex=-1;
+       options->gss_use_session_ccache = -1;
+       options->gss_cleanup_creds = -1;
+#endif
 #if defined(KRB4) || defined(KRB5)
        options->kerberos_authentication = -1;
        options->kerberos_or_local_passwd = -1;
@@ -187,6 +193,16 @@ fill_default_server_options(ServerOptions *options)
                options->rsa_authentication = 1;
        if (options->pubkey_authentication == -1)
                options->pubkey_authentication = 1;
+#ifdef GSSAPI
+       if (options->gss_authentication == -1)
+               options->gss_authentication = 1;
+       if (options->gss_keyex == -1)
+               options->gss_keyex =1;
+       if (options->gss_use_session_ccache == -1)
+               options->gss_use_session_ccache = 1;
+       if (options->gss_cleanup_creds == -1)
+               options->gss_cleanup_creds = 1;
+#endif
 #if defined(KRB4) || defined(KRB5)
        if (options->kerberos_authentication == -1)
                options->kerberos_authentication = (access(KEYFILE, R_OK) == 0);
@@ -249,6 +265,9 @@ typedef enum {
        sPort, sHostKeyFile, sServerKeyBits, sLoginGraceTime, sKeyRegenerationTime,
        sPermitRootLogin, sLogFacility, sLogLevel,
        sRhostsAuthentication, sRhostsRSAAuthentication, sRSAAuthentication,
+#ifdef GSSAPI
+       sGssAuthentication, sGssKeyEx, sGssUseSessionCredCache, sGssCleanupCreds,
+#endif
 #if defined(KRB4) || defined(KRB5)
        sKerberosAuthentication, sKerberosOrLocalPasswd, sKerberosTicketCleanup,
 #endif
@@ -298,6 +317,13 @@ static struct {
        { "rsaauthentication", sRSAAuthentication },
        { "pubkeyauthentication", sPubkeyAuthentication },
        { "dsaauthentication", sPubkeyAuthentication },                 /* alias */
+#ifdef GSSAPI
+       { "gssapiauthentication", sGssAuthentication },
+       { "gssapikeyexchange", sGssKeyEx },
+       { "gssusesessionccache", sGssUseSessionCredCache },
+       { "gssapiusesessioncredcache", sGssUseSessionCredCache },
+       { "gssapicleanupcreds", sGssCleanupCreds },
+#endif
 #if defined(KRB4) || defined(KRB5)
        { "kerberosauthentication", sKerberosAuthentication },
        { "kerberosorlocalpasswd", sKerberosOrLocalPasswd },
@@ -623,6 +649,20 @@ parse_flag:
                case sPubkeyAuthentication:
                        intptr = &options->pubkey_authentication;
                        goto parse_flag;
+#ifdef GSSAPI
+               case sGssAuthentication:
+                       intptr = &options->gss_authentication;
+                       goto parse_flag;
+               case sGssKeyEx:
+                       intptr = &options->gss_keyex;
+                       goto parse_flag;
+               case sGssUseSessionCredCache:
+                       intptr = &options->gss_use_session_ccache;
+                       goto parse_flag;
+               case sGssCleanupCreds:
+                       intptr = &options->gss_cleanup_creds;
+                       goto parse_flag;
+#endif
 #if defined(KRB4) || defined(KRB5)
                case sKerberosAuthentication:
                        intptr = &options->kerberos_authentication;
index 2e10b1c33edbebf1d1c6023c01bdcf16e1974935..e58e994c5f871326aaf76a91b7c4d2284c3c35bf 100644 (file)
@@ -72,6 +72,13 @@ typedef struct {
        int     hostbased_uses_name_from_packet_only; /* experimental */
        int     rsa_authentication;     /* If true, permit RSA authentication. */
        int     pubkey_authentication;  /* If true, permit ssh2 pubkey authentication. */
+       #ifdef GSSAPI
+       int     gss_authentication;
+       int     gss_keyex;
+       int     gss_use_session_ccache;        /* If true, delegated credentials are
+                                               * stored in a session specific cache */
+       int     gss_cleanup_creds;             /* If true, destroy cred cache on logout */
+#endif 
 #if defined(KRB4) || defined(KRB5)
        int     kerberos_authentication;        /* If true, permit Kerberos
                                                 * authentication. */
index 02c0c5264f7789dd35e7fe04a66e022cf072c9c6..d7e4806e0560ed7411dc664f483931e8a341e37f 100644 (file)
@@ -57,6 +57,10 @@ RCSID("$OpenBSD: session.c,v 1.108 2001/10/11 13:45:21 markus Exp $");
 #include "canohost.h"
 #include "session.h"
 
+#ifdef GSSAPI
+#include "ssh-gss.h"
+#endif
+
 #ifdef WITH_IRIX_PROJECT
 #include <proj.h>
 #endif /* WITH_IRIX_PROJECT */
@@ -436,6 +440,12 @@ do_exec_no_pty(Session *s, const char *command)
 
        session_proctitle(s);
 
+#if defined(GSSAPI)
+       temporarily_use_uid(s->pw);
+       ssh_gssapi_storecreds();
+       restore_uid();
+#endif
+
 #if defined(USE_PAM)
        do_pam_session(s->pw->pw_name, NULL);
        do_pam_setcred(1);
@@ -554,6 +564,12 @@ do_exec_pty(Session *s, const char *command)
        ptyfd = s->ptyfd;
        ttyfd = s->ttyfd;
 
+#if defined(GSSAPI)
+       temporarily_use_uid(s->pw);
+       ssh_gssapi_storecreds();
+       restore_uid();
+#endif
+
 #if defined(USE_PAM)
        do_pam_session(s->pw->pw_name, s->tty);
        do_pam_setcred(1);
@@ -807,7 +823,7 @@ check_quietlogin(Session *s, const char *command)
  * Sets the value of the given variable in the environment.  If the variable
  * already exists, its value is overriden.
  */
-static void
+void
 child_set_env(char ***envp, u_int *envsizep, const char *name,
              const char *value)
 {
@@ -1121,6 +1137,7 @@ do_child(Session *s, const char *command)
                                exit(1);
                        }
                        endgrent();
+
 #  ifdef USE_PAM
                        /*
                         * PAM credentials may take the form of 
@@ -1216,6 +1233,13 @@ do_child(Session *s, const char *command)
        copy_environment(&env, &envsize);
 #endif
 
+#ifdef GSSAPI
+       /* Allow any GSSAPI methods that we've used to alter 
+        * the childs environment as they see fit
+        */
+       ssh_gssapi_do_child(&env,&envsize);
+#endif
+
        if (!options.use_login) {
                /* Set basic environment. */
                child_set_env(&env, &envsize, "USER", pw->pw_name);
@@ -2074,4 +2098,7 @@ static void
 do_authenticated2(Authctxt *authctxt)
 {
        server_loop2(authctxt);
+#if defined(GSSAPI)
+       ssh_gssapi_cleanup_creds(NULL);
+#endif
 }
index 6d5b8e69922dd89bcee8e7c644b77d4c9d1ad90a..e752c66b9f569d83c1edaa297d6b7d01528c3fc5 100644 (file)
@@ -33,5 +33,6 @@ void   session_input_channel_req(int, void *);
 void    session_close_by_pid(pid_t, int);
 void    session_close_by_channel(int, void *);
 void    session_destroy_all(void);
-
+void    child_set_env(char ***envp, u_int *envsizep, const char *name,
+                      const char *value);
 #endif
diff --git a/openssh/ssh-gss.h b/openssh/ssh-gss.h
new file mode 100644 (file)
index 0000000..7442a43
--- /dev/null
@@ -0,0 +1,122 @@
+/*
+ * Copyright (c) 2001 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.
+ */
+
+#ifdef GSSAPI
+
+#include "kex.h"
+#include "buffer.h"
+
+#include <gssapi.h>
+
+#ifdef KRB5
+#ifndef HEIMDAL
+#include <gssapi_generic.h>
+
+/* MIT Kerberos doesn't seem to define GSS_NT_HOSTBASED_SERVICE */
+
+#ifndef GSS_C_NT_HOSTBASED_SERVICE
+#define GSS_C_NT_HOSTBASED_SERVICE gss_nt_service_name
+#endif /* GSS_C_NT_... */
+#endif /* !HEIMDAL */
+#endif /* KRB5 */
+
+/* draft-ietf-secsh-gsskeyex-01 */
+#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 KEX_GSS_SHA1                   "gss-group1-sha1-"
+
+/* draft-galb-secsh-gssapi-01 */
+#define SSH2_MSG_USERAUTH_GSSAPI_RESPONSE     60
+#define SSH2_MSG_USERAUTH_GSSAPI_TOKEN        61
+#define SSH2_MSG_USERAUTH_GSSAPI_HASH         62
+#define SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE     63    
+
+enum ssh_gss_id {
+#ifdef KRB5
+       GSS_KERBEROS,
+#endif
+#ifdef GSI
+       GSS_GSI,
+#endif /* GSI */
+       GSS_LAST_ENTRY
+};
+
+typedef struct ssh_gss_mech_struct {
+        char *enc_name;
+        char *name;
+        gss_OID_desc oid;
+} ssh_gssapi_mech;
+
+typedef struct {
+       OM_uint32       status; /* both */
+       gss_ctx_id_t    context; /* both */
+       gss_name_t      name; /* both */
+       gss_OID         oid; /* client */
+       gss_cred_id_t   creds; /* server */
+       gss_name_t      client; /* server */
+       gss_cred_id_t   client_creds; /* server */
+} Gssctxt;
+
+extern ssh_gssapi_mech supported_mechs[];
+extern gss_buffer_desc gssapi_client_name;
+extern gss_cred_id_t   gssapi_client_creds;
+extern enum ssh_gss_id gssapi_client_type;
+
+char *ssh_gssapi_mechanisms(int server, char *host);
+int ssh_gssapi_id_kex(Gssctxt *ctx, char *name);
+void ssh_gssapi_set_oid_data(Gssctxt *ctx, void *data, size_t len);
+void ssh_gssapi_set_oid(Gssctxt *ctx, gss_OID oid);
+void ssh_gssapi_supported_oids(gss_OID_set *oidset);
+enum ssh_gss_id ssh_gssapi_get_ctype(Gssctxt *ctxt);
+
+OM_uint32 ssh_gssapi_import_name(Gssctxt *ctx, char *host);
+OM_uint32 ssh_gssapi_acquire_cred(Gssctxt *ctx);
+OM_uint32 ssh_gssapi_init_ctx(Gssctxt *ctx, int deleg_creds,
+                             gss_buffer_desc *recv_tok, 
+                             gss_buffer_desc *send_tok, OM_uint32 *flags);
+OM_uint32 ssh_gssapi_accept_ctx(Gssctxt *ctx,
+                               gss_buffer_desc *recv_tok,
+                               gss_buffer_desc *send_tok,
+                               OM_uint32 *flags);
+OM_uint32 ssh_gssapi_getclient(Gssctxt *ctx,
+                               enum ssh_gss_id *type,
+                               gss_buffer_desc *name,
+                               gss_cred_id_t *creds);
+void ssh_gssapi_error(OM_uint32 major_status,OM_uint32 minor_status);
+void ssh_gssapi_build_ctx(Gssctxt *ctx);
+void ssh_gssapi_delete_ctx(Gssctxt *ctx);
+
+/* In the client */
+void ssh_gssapi_client(Kex *kex, char *host, struct sockaddr *hostaddr,
+                       Buffer *client_kexinit, Buffer *server_kexinit);
+
+/* In the server */
+void ssh_gssapi_server(Kex *kex, Buffer *client_kexinit, 
+                      Buffer *server_kexinit);
+void ssh_gssapi_do_child(char ***envp, u_int *envsizep);                 
+void ssh_gssapi_cleanup_creds(void *ignored);
+void ssh_gssapi_storecreds();
+#endif /* GSSAPI */
index 310788538a27bafa758f246b1c40a430857e4ccb..d97aed4537a49580fd206fa991263cd875afcf38 100644 (file)
@@ -54,6 +54,10 @@ RCSID("$OpenBSD: sshconnect2.c,v 1.85 2001/11/07 16:03:17 markus Exp $");
 #include "dispatch.h"
 #include "canohost.h"
 
+#ifdef GSSAPI
+#include "ssh-gss.h"
+#endif
+
 /* import */
 extern char *client_version_string;
 extern char *server_version_string;
@@ -87,6 +91,30 @@ ssh_kex2(char *host, struct sockaddr *hostaddr)
        xxx_host = host;
        xxx_hostaddr = hostaddr;
 
+#ifdef GSSAPI
+       /* This is a bit of a nasty kludge. This adds the GSSAPI included
+        * key exchange methods to the top of the list, allowing the GSSAPI
+        * code to decide whether each one should be included or not.
+        */     
+       {
+               char *orig, *gss;
+               int len;
+               orig = myproposal[PROPOSAL_KEX_ALGS];
+               gss = ssh_gssapi_mechanisms(0,host);
+               if (gss) {
+                  len = strlen(orig)+strlen(gss)+2;
+                  myproposal[PROPOSAL_KEX_ALGS]=xmalloc(len);
+                  snprintf(myproposal[PROPOSAL_KEX_ALGS],len,"%s,%s",gss,orig);
+                  /* If we've got GSSAPI algorithms, then we also support the
+                   * 'null' hostkey, as a last resort */
+                  orig=myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS];
+                  len = strlen(orig)+sizeof(",null");
+                  myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS]=xmalloc(len);
+                  snprintf(myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS],len,"%s,null",orig);  
+               }
+       }
+#endif
+
        if (options.ciphers == (char *)-1) {
                log("No valid ciphers for protocol version 2 given, using defaults.");
                options.ciphers = NULL;
@@ -119,6 +147,11 @@ ssh_kex2(char *host, struct sockaddr *hostaddr)
        kex->client_version_string=client_version_string;
        kex->server_version_string=server_version_string;
        kex->verify_host_key=&verify_host_key_callback;
+       kex->host=host;
+
+#ifdef GSSAPI
+       kex->options.gss_deleg_creds=options.gss_deleg_creds;
+#endif
 
        xxx_kex = kex;
 
@@ -166,6 +199,8 @@ struct Authctxt {
        int nkeys;
        /* kbd-interactive */
        int info_req_seen;
+       /* generic */
+       void *methoddata;
 };
 struct Authmethod {
        char    *name;          /* string to compare against server's list */
@@ -187,6 +222,16 @@ int        userauth_passwd(Authctxt *authctxt);
 int    userauth_kbdint(Authctxt *authctxt);
 int    userauth_hostbased(Authctxt *authctxt);
 
+#ifdef GSSAPI
+int     userauth_external(Authctxt *authctxt);
+int     userauth_gssapi(Authctxt *authctxt);
+void    input_gssapi_response(int type, int plen, void *ctxt);
+void    input_gssapi_token(int type, int plen, void *ctxt);
+void    input_gssapi_hash(int type, int plen, void *ctxt);
+
+int     gss_host_key_ok=0;
+#endif
+
 void   userauth(Authctxt *authctxt, char *authlist);
 
 static int sign_and_send_pubkey(Authctxt *, Key *, sign_cb_fn *);
@@ -197,6 +242,16 @@ static Authmethod *authmethod_lookup(const char *name);
 static char *authmethods_get(void);
 
 Authmethod authmethods[] = {
+#ifdef GSSAPI
+       {"external-keyx",
+               userauth_external,
+               &options.gss_authentication,
+               NULL},
+       {"gssapi",
+               userauth_gssapi,
+               &options.gss_authentication,
+               NULL},
+#endif
        {"hostbased",
                userauth_hostbased,
                &options.hostbased_authentication,
@@ -263,6 +318,7 @@ ssh_userauth2(const char *local_user, const char *server_user, char *host,
        authctxt.success = 0;
        authctxt.method = authmethod_lookup("none");
        authctxt.authlist = NULL;
+       authctxt.methoddata = NULL;
        authctxt.keys = keys;
        authctxt.nkeys = nkeys;
        authctxt.info_req_seen = 0;
@@ -286,6 +342,11 @@ ssh_userauth2(const char *local_user, const char *server_user, char *host,
 void
 userauth(Authctxt *authctxt, char *authlist)
 {
+       if (authctxt->methoddata!=NULL) {
+               xfree(authctxt->methoddata);
+               authctxt->methoddata=NULL;
+       }
+           
        if (authlist == NULL) {
                authlist = authctxt->authlist;
        } else {
@@ -332,6 +393,8 @@ input_userauth_success(int type, int plen, void *ctxt)
                fatal("input_userauth_success: no authentication context");
        if (authctxt->authlist)
                xfree(authctxt->authlist);
+       if (authctxt->methoddata)
+               xfree(authctxt->methoddata);
        clear_auth_state(authctxt);
        authctxt->success = 1;                  /* break out */
 }
@@ -424,6 +487,151 @@ input_userauth_pk_ok(int type, int plen, void *ctxt)
 
 }
 
+#ifdef GSSAPI
+int 
+userauth_gssapi(Authctxt *authctxt)
+{
+       int i;
+       Gssctxt *gssctxt;
+       static int tries=0;
+
+       /* For now, we only make one attempt at this. We could try offering
+        * the server different GSSAPI OIDs until we get bored, I suppose.
+        */     
+       if (tries++>0) return 0;
+
+        gssctxt=xmalloc(sizeof(Gssctxt));
+
+       /* Initialise as much of our context as we can, so failures can be
+        * trapped before sending any packets.
+        */
+       ssh_gssapi_build_ctx(gssctxt);
+       if (ssh_gssapi_import_name(gssctxt,authctxt->host)) {
+               return(0);
+       }
+       authctxt->methoddata=(void *)gssctxt;
+               
+       packet_start(SSH2_MSG_USERAUTH_REQUEST);
+       packet_put_cstring(authctxt->server_user);
+       packet_put_cstring(authctxt->service);
+        packet_put_cstring(authctxt->method->name);
+
+       /* FIXME: This assumes that our current GSSAPI implementation
+        * supports all of the mechanisms listed in supported_mechs.
+        * This may not be the case - we should use something along
+        * the lines of the code in gss_genr to remove the ones that
+        * aren't supported */
+       packet_put_int(GSS_LAST_ENTRY);
+       for (i=0;i<GSS_LAST_ENTRY;i++) {
+               packet_put_string(supported_mechs[i].oid.elements,
+                                 supported_mechs[i].oid.length);
+       }
+        packet_send();
+        packet_write_wait();
+
+        dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE,&input_gssapi_response);
+        dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN,&input_gssapi_token);
+       
+        return 1;
+}
+
+void
+input_gssapi_response(int type, int plen, void *ctxt) 
+{
+       Authctxt *authctxt = ctxt;
+       Gssctxt *gssctxt;
+       OM_uint32 status,ms;
+       int oidlen;
+       char *oidv;
+       gss_buffer_desc send_tok;
+       
+       if (authctxt == NULL)
+               fatal("input_gssapi_response: no authentication context");
+       gssctxt = authctxt->methoddata;
+       
+       /* Setup our OID */
+       oidv=packet_get_string(&oidlen);
+       ssh_gssapi_set_oid_data(gssctxt,oidv,oidlen);
+       
+       packet_done();
+       
+       status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
+                                    GSS_C_NO_BUFFER, &send_tok, 
+                                    NULL);
+       if (GSS_ERROR(status)) {
+               /* Start again with next method on list */
+               debug("Trying to start again");
+               userauth(authctxt,NULL);
+               return;
+       }
+
+       /* We must have data to send */                                 
+       packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
+       packet_put_string(send_tok.value,send_tok.length);
+       packet_send();
+       packet_write_wait();
+       gss_release_buffer(&ms, &send_tok);
+}
+
+void
+input_gssapi_token(int type, int plen, void *ctxt)
+{
+       Authctxt *authctxt = ctxt;
+       Gssctxt *gssctxt;
+       gss_buffer_desc send_tok,recv_tok;
+       OM_uint32 status;
+       
+       if (authctxt == NULL)
+               fatal("input_gssapi_response: no authentication context");
+       gssctxt = authctxt->methoddata;
+       
+       recv_tok.value=packet_get_string(&recv_tok.length);
+
+       status=ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
+                                  &recv_tok, &send_tok, NULL);
+
+       packet_done();
+       
+       if (GSS_ERROR(status)) {
+               /* Start again with the next method in the list */
+               userauth(authctxt,NULL);
+               return;
+       }
+       
+       if (send_tok.length>0) {
+               packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
+               packet_put_string(send_tok.value,send_tok.length);
+               packet_send();
+               packet_write_wait();
+       }
+       
+       if (status == GSS_S_COMPLETE) {
+               /* If that succeeded, send a exchange complete message */
+               packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE);
+               packet_send();
+               packet_write_wait();
+       }
+}
+
+int
+userauth_external(Authctxt *authctxt)
+{
+        static int attempt =0;
+        
+        if (attempt++ >= 1)
+               return 0;
+                                
+        debug2("userauth_external");
+        packet_start(SSH2_MSG_USERAUTH_REQUEST);
+        packet_put_cstring(authctxt->server_user);
+        packet_put_cstring(authctxt->service);
+        packet_put_cstring(authctxt->method->name);
+        packet_send();
+        packet_write_wait();
+        return 1;
+}                                                                                                
+#endif /* GSSAPI */
+
 int
 userauth_none(Authctxt *authctxt)
 {
@@ -434,6 +642,7 @@ userauth_none(Authctxt *authctxt)
        packet_put_cstring(authctxt->method->name);
        packet_send();
        return 1;
+
 }
 
 int
index 5a6624b7420112372f51d88a800075c37fa92216..ab83cfb48c34bfd3f21725713ac392525f7b29b5 100644 (file)
@@ -466,6 +466,25 @@ This option is similar to
 and applies to protocol version 2 only.
 The default is
 .Dq no .
+.It Cm GssapiAuthentication
+Specifies whether authentication based on GSSAPI may be used, either using
+the result of a successful key exchange, or using GSSAPI user
+authentication.
+The default is 
+.Dq yes .
+Note that this option applies to protocol version 2 only.
+.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 yes .
+Note that this option applies to protocol version 2 only.
+.It Cm GssapiUseSessionCredCache
+Specifies whether a unique credentials cache name should be generated per
+session for storing delegated credentials.
+The default is
+.Dq yes .
+Note that this option applies to protocol version 2 only.
 .It Cm HostKey
 Specifies the file containing the private host keys (default
 .Pa /etc/ssh_host_key )
index 71a5c2c2e98c6dcc530ec69e1ba014511e8d31de..5c7d8d0f5322862e76b1d669d218881c1a8e58da 100644 (file)
@@ -73,6 +73,10 @@ RCSID("$OpenBSD: sshd.c,v 1.209 2001/11/10 13:19:45 markus Exp $");
 #include "dispatch.h"
 #include "channels.h"
 
+#ifdef GSSAPI
+#include "ssh-gss.h"
+#endif
+
 #ifdef LIBWRAP
 #include <tcpd.h>
 #include <syslog.h>
@@ -739,10 +743,13 @@ main(int ac, char **av)
                log("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) {
                log("Disabling protocol version 2. Could not load host key");
                options.protocol &= ~SSH_PROTO_2;
        }
+#endif
        if (!(options.protocol & (SSH_PROTO_1|SSH_PROTO_2))) {
                log("sshd: no hostkeys available -- exiting.");
                exit(1);
@@ -1463,6 +1470,45 @@ do_ssh2_kex(void)
        }
        myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = 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 all of the algorithms
+        * currently in myproposal are useless */
+       if (strlen(myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS])==0)
+               orig= NULL;
+               
+        if (options.gss_keyex)
+               gss = ssh_gssapi_mechanisms(1,NULL);
+        else
+               gss = NULL;
+        
+       if (gss && orig) {
+               int len = strlen(orig) + strlen(gss) +2;
+               newstr=xmalloc(len);
+               snprintf(newstr,len,"%s,%s",gss,orig);
+       } else if (gss) {
+               newstr=gss;
+       } else if (orig) {
+               newstr=orig;
+       }
+        /* If we've got GSSAPI mechanisms, then we've also got the 'null'
+          host key algorithm, but we're not allowed to advertise it, unless
+          its the only host key algorithm we're supporting */
+       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 */
        kex = kex_setup(myproposal);
        kex->server = 1;
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