s3-krb5 Fix Kerberos on FreeBSD with Samba4 DCs
[samba.git] / source3 / libsmb / clikrb5.c
index 0839b434c1ee938cbb007587dabd742d1cbd2fdd..704bcb929ec66fd26c27b12f8ab4e769b8c76b24 100644 (file)
 
 #include "includes.h"
 #include "smb_krb5.h"
+#include "../librpc/gen_ndr/krb5pac.h"
+
+#ifndef KRB5_AUTHDATA_WIN2K_PAC
+#define KRB5_AUTHDATA_WIN2K_PAC 128
+#endif
+
+#ifndef KRB5_AUTHDATA_IF_RELEVANT
+#define KRB5_AUTHDATA_IF_RELEVANT 1
+#endif
 
 #ifdef HAVE_KRB5
 
 #define GSSAPI_CHECKSUM      0x8003             /* Checksum type value for Kerberos */
 #define GSSAPI_BNDLENGTH     16                 /* Bind Length (rfc-1964 pg.3) */
-#define GSSAPI_CHECKSUM_SIZE (12+GSSAPI_BNDLENGTH)
-
-#if defined(TKT_FLG_OK_AS_DELEGATE ) && defined(HAVE_KRB5_FWD_TGT_CREDS) && defined(HAVE_KRB5_AUTH_CON_SET_REQ_CKSUMTYPE) && defined(KRB5_AUTH_CONTEXT_USE_SUBKEY)
-static krb5_error_code ads_krb5_get_fwd_ticket( krb5_context context,
-                                         krb5_auth_context *auth_context,
-                                         krb5_creds *credsp,
-                                         krb5_ccache ccache,
-                                         krb5_data *authenticator);
+#define GSSAPI_CHECKSUM_SIZE (4+GSSAPI_BNDLENGTH+4) /* Length of bind length,
+                                                       bind field, flags field. */
+
+/* MIT krb5 1.7beta3 (in Ubuntu Karmic) is missing the prototype,
+   but still has the symbol */
+#if !HAVE_DECL_KRB5_AUTH_CON_SET_REQ_CKSUMTYPE
+krb5_error_code krb5_auth_con_set_req_cksumtype(  
+       krb5_context     context,
+       krb5_auth_context      auth_context,  
+       krb5_cksumtype     cksumtype);
 #endif
 
 /**************************************************************
@@ -644,6 +655,92 @@ static bool ads_cleanup_expired_creds(krb5_context context,
        return True;
 }
 
+/* Allocate and setup the auth context into the state we need. */
+
+static krb5_error_code setup_auth_context(krb5_context context,
+                       krb5_auth_context *auth_context)
+{
+       krb5_error_code retval;
+
+       retval = krb5_auth_con_init(context, auth_context );
+       if (retval) {
+               DEBUG(1,("krb5_auth_con_init failed (%s)\n",
+                       error_message(retval)));
+               return retval;
+       }
+
+       /* Ensure this is an addressless ticket. */
+       retval = krb5_auth_con_setaddrs(context, *auth_context, NULL, NULL);
+       if (retval) {
+               DEBUG(1,("krb5_auth_con_setaddrs failed (%s)\n",
+                       error_message(retval)));
+       }
+
+       return retval;
+}
+
+static krb5_error_code create_gss_checksum(krb5_data *in_data, /* [inout] */
+                                               uint32_t gss_flags)
+{
+       unsigned int orig_length = in_data->length;
+       unsigned int base_cksum_size = GSSAPI_CHECKSUM_SIZE;
+       char *gss_cksum = NULL;
+
+       if (orig_length) {
+               /* Extra length field for delgated ticket. */
+               base_cksum_size += 4;
+       }
+
+       if ((unsigned int)base_cksum_size + orig_length <
+                       (unsigned int)base_cksum_size) {
+                return EINVAL;
+        }
+
+       gss_cksum = (char *)SMB_MALLOC(base_cksum_size + orig_length);
+       if (gss_cksum == NULL) {
+               return ENOMEM;
+        }
+
+       memset(gss_cksum, '\0', base_cksum_size + orig_length);
+       SIVAL(gss_cksum, 0, GSSAPI_BNDLENGTH);
+
+       /* Precalculated MD5sum of NULL channel bindings (20 bytes) */
+       /* Channel bindings are: (all ints encoded as little endian)
+
+               [4 bytes] initiator_addrtype (255 for null bindings)
+               [4 bytes] initiator_address length
+                       [n bytes] .. initiator_address data - not present
+                                    in null bindings.
+               [4 bytes] acceptor_addrtype (255 for null bindings)
+               [4 bytes] acceptor_address length
+                       [n bytes] .. acceptor_address data - not present
+                                    in null bindings.
+               [4 bytes] application_data length
+                       [n bytes] .. application_ data - not present
+                                    in null bindings.
+               MD5 of this is ""\x14\x8f\x0c\xf7\xb1u\xdey*J\x9a%\xdfV\xc5\x18"
+       */
+
+       memcpy(&gss_cksum[4],
+               "\x14\x8f\x0c\xf7\xb1u\xdey*J\x9a%\xdfV\xc5\x18",
+               GSSAPI_BNDLENGTH);
+
+       SIVAL(gss_cksum, 20, gss_flags);
+
+       if (orig_length) {
+               SSVAL(gss_cksum, 24, 1); /* The Delegation Option identifier */
+               SSVAL(gss_cksum, 26, orig_length);
+               /* Copy the kerberos KRB_CRED data */
+               memcpy(gss_cksum + 28, in_data->data, orig_length);
+               free(in_data->data);
+               in_data->data = NULL;
+               in_data->length = 0;
+       }
+       in_data->data = gss_cksum;
+       in_data->length = base_cksum_size + orig_length;
+       return 0;
+}
+
 /*
   we can't use krb5_mk_req because w2k wants the service to be in a particular format
 */
@@ -664,7 +761,8 @@ static krb5_error_code ads_krb5_mk_req(krb5_context context,
        krb5_data in_data;
        bool creds_ready = False;
        int i = 0, maxtries = 3;
-       
+       uint32_t gss_flags = 0;
+
        ZERO_STRUCT(in_data);
 
        retval = smb_krb5_parse_name(context, principal, &server);
@@ -734,45 +832,51 @@ static krb5_error_code ads_krb5_mk_req(krb5_context context,
                *expire_time = (time_t)credsp->times.endtime;
        }
 
-#if defined(TKT_FLG_OK_AS_DELEGATE ) && defined(HAVE_KRB5_FWD_TGT_CREDS) && defined(HAVE_KRB5_AUTH_CON_SET_REQ_CKSUMTYPE) && defined(KRB5_AUTH_CONTEXT_USE_SUBKEY)
+       /* Allocate the auth_context. */
+       retval = setup_auth_context(context, auth_context);
+       if (retval) {
+               DEBUG(1,("setup_auth_context failed (%s)\n",
+                       error_message(retval)));
+               goto cleanup_creds;
+       }
+
+#if defined(TKT_FLG_OK_AS_DELEGATE ) && defined(HAVE_KRB5_FWD_TGT_CREDS) && defined(HAVE_KRB5_AUTH_CON_SETUSERUSERKEY) && defined(KRB5_AUTH_CONTEXT_USE_SUBKEY) && defined(HAVE_KRB5_AUTH_CON_SET_REQ_CKSUMTYPE)
        if( credsp->ticket_flags & TKT_FLG_OK_AS_DELEGATE ) {
                /* Fetch a forwarded TGT from the KDC so that we can hand off a 2nd ticket
                 as part of the kerberos exchange. */
 
                DEBUG( 3, ("ads_krb5_mk_req: server marked as OK to delegate to, building forwardable TGT\n")  );
 
-               if( *auth_context == NULL ) {
-                       /* Allocate if it has not yet been allocated. */
-                       retval = krb5_auth_con_init( context, auth_context );
-                       if (retval) {
-                               DEBUG(1,("ads_krb5_mk_req: krb5_auth_con_init failed (%s)\n",
-                                       error_message(retval)));
-                               goto cleanup_creds;
-                       }
-               }
-
-               retval = krb5_auth_con_setuseruserkey( context, *auth_context, &credsp->keyblock );
+               retval = krb5_auth_con_setuseruserkey(context,
+                                       *auth_context,
+                                       &credsp->keyblock );
                if (retval) {
-                       DEBUG(1,("ads_krb5_mk_req: krb5_auth_con_setuseruserkey failed (%s)\n",
+                       DEBUG(1,("krb5_auth_con_setuseruserkey failed (%s)\n",
                                error_message(retval)));
                        goto cleanup_creds;
                }
 
                /* Must use a subkey for forwarded tickets. */
-               retval = krb5_auth_con_setflags( context, *auth_context, KRB5_AUTH_CONTEXT_USE_SUBKEY);
+               retval = krb5_auth_con_setflags(context,
+                               *auth_context,
+                               KRB5_AUTH_CONTEXT_USE_SUBKEY);
                if (retval) {
-                       DEBUG(1,("ads_krb5_mk_req: krb5_auth_con_setflags failed (%s)\n",
+                       DEBUG(1,("krb5_auth_con_setflags failed (%s)\n",
                                error_message(retval)));
                        goto cleanup_creds;
                }
 
-               retval = ads_krb5_get_fwd_ticket( context,
-                                               auth_context,
-                                               credsp,
-                                               ccache,
-                                               &in_data );
+               retval = krb5_fwd_tgt_creds(context,/* Krb5 context [in] */
+                               *auth_context,  /* Authentication context [in] */
+                               CONST_DISCARD(char *, KRB5_TGS_NAME),  /* Ticket service name ("krbtgt") [in] */
+                               credsp->client, /* Client principal for the tgt [in] */
+                               credsp->server, /* Server principal for the tgt [in] */
+                               ccache,         /* Credential cache to use for storage [in] */
+                               1,              /* Turn on for "Forwardable ticket" [in] */
+                               &in_data );     /* Resulting response [out] */
+
                if (retval) {
-                       DEBUG( 3, ("ads_krb5_get_fwd_ticket failed (%s)\n",
+                       DEBUG( 3, ("krb5_fwd_tgt_creds failed (%s)\n",
                                   error_message( retval ) ) );
 
                        /*
@@ -787,8 +891,31 @@ static krb5_error_code ads_krb5_mk_req(krb5_context context,
                        }
                        krb5_auth_con_free(context, *auth_context);
                        *auth_context = NULL;
+                       retval = setup_auth_context(context, auth_context);
+                       if (retval) {
+                               DEBUG(1,("setup_auth_context failed (%s)\n",
+                                       error_message(retval)));
+                               goto cleanup_creds;
+                       }
+               } else {
+                       /* We got a delegated ticket. */
+                       gss_flags |= GSS_C_DELEG_FLAG;
                }
        }
+
+       /* Frees and reallocates in_data into a GSS checksum blob. */
+       retval = create_gss_checksum(&in_data, gss_flags);
+       if (retval) {
+               goto cleanup_data;
+       }
+
+       /* We always want GSS-checksum types. */
+       retval = krb5_auth_con_set_req_cksumtype(context, *auth_context, GSSAPI_CHECKSUM );
+       if (retval) {
+               DEBUG(1,("krb5_auth_con_set_req_cksumtype failed (%s)\n",
+                       error_message(retval)));
+               goto cleanup_data;
+       }
 #endif
 
        retval = krb5_mk_req_extended(context, auth_context, ap_req_options, 
@@ -798,6 +925,7 @@ static krb5_error_code ads_krb5_mk_req(krb5_context context,
                         error_message(retval)));
        }
 
+cleanup_data:
        if (in_data.data) {
                free( in_data.data );
                in_data.length = 0;
@@ -818,11 +946,12 @@ cleanup_princ:
 }
 
 /*
-  get a kerberos5 ticket for the given service 
+  get a kerberos5 ticket for the given service
 */
-int cli_krb5_get_ticket(const char *principal, time_t time_offset, 
-                       DATA_BLOB *ticket, DATA_BLOB *session_key_krb5, 
-                       uint32 extra_ap_opts, const char *ccname, 
+int cli_krb5_get_ticket(TALLOC_CTX *mem_ctx,
+                       const char *principal, time_t time_offset,
+                       DATA_BLOB *ticket, DATA_BLOB *session_key_krb5,
+                       uint32_t extra_ap_opts, const char *ccname,
                        time_t *tgs_expire,
                        const char *impersonate_princ_s)
 
@@ -833,17 +962,15 @@ int cli_krb5_get_ticket(const char *principal, time_t time_offset,
        krb5_ccache ccdef = NULL;
        krb5_auth_context auth_context = NULL;
        krb5_enctype enc_types[] = {
-#ifdef ENCTYPE_ARCFOUR_HMAC
                ENCTYPE_ARCFOUR_HMAC,
-#endif 
-               ENCTYPE_DES_CBC_MD5, 
-               ENCTYPE_DES_CBC_CRC, 
+               ENCTYPE_DES_CBC_MD5,
+               ENCTYPE_DES_CBC_CRC,
                ENCTYPE_NULL};
 
        initialize_krb5_error_table();
        retval = krb5_init_context(&context);
        if (retval) {
-               DEBUG(1,("cli_krb5_get_ticket: krb5_init_context failed (%s)\n", 
+               DEBUG(1, ("krb5_init_context failed (%s)\n",
                         error_message(retval)));
                goto failed;
        }
@@ -854,56 +981,60 @@ int cli_krb5_get_ticket(const char *principal, time_t time_offset,
 
        if ((retval = krb5_cc_resolve(context, ccname ?
                        ccname : krb5_cc_default_name(context), &ccdef))) {
-               DEBUG(1,("cli_krb5_get_ticket: krb5_cc_default failed (%s)\n",
+               DEBUG(1, ("krb5_cc_default failed (%s)\n",
                         error_message(retval)));
                goto failed;
        }
 
        if ((retval = krb5_set_default_tgs_ktypes(context, enc_types))) {
-               DEBUG(1,("cli_krb5_get_ticket: krb5_set_default_tgs_ktypes failed (%s)\n",
+               DEBUG(1, ("krb5_set_default_tgs_ktypes failed (%s)\n",
                         error_message(retval)));
                goto failed;
        }
 
-       if ((retval = ads_krb5_mk_req(context, 
-                                       &auth_context, 
-                                       AP_OPTS_USE_SUBKEY | (krb5_flags)extra_ap_opts,
-                                       principal,
-                                       ccdef, &packet,
-                                       tgs_expire,
-                                       impersonate_princ_s))) {
+       retval = ads_krb5_mk_req(context, &auth_context,
+                               AP_OPTS_USE_SUBKEY | (krb5_flags)extra_ap_opts,
+                               principal, ccdef, &packet,
+                               tgs_expire, impersonate_princ_s);
+       if (retval) {
                goto failed;
        }
 
-       get_krb5_smb_session_key(context, auth_context, session_key_krb5, False);
+       get_krb5_smb_session_key(mem_ctx, context, auth_context,
+                                session_key_krb5, false);
 
-       *ticket = data_blob(packet.data, packet.length);
+       *ticket = data_blob_talloc(mem_ctx, packet.data, packet.length);
 
-       kerberos_free_data_contents(context, &packet); 
+       kerberos_free_data_contents(context, &packet);
 
 failed:
 
-       if ( context ) {
+       if (context) {
                if (ccdef)
                        krb5_cc_close(context, ccdef);
                if (auth_context)
                        krb5_auth_con_free(context, auth_context);
                krb5_free_context(context);
        }
-               
+
        return retval;
 }
 
- bool get_krb5_smb_session_key(krb5_context context, krb5_auth_context auth_context, DATA_BLOB *session_key, bool remote)
- {
+bool get_krb5_smb_session_key(TALLOC_CTX *mem_ctx,
+                             krb5_context context,
+                             krb5_auth_context auth_context,
+                             DATA_BLOB *session_key, bool remote)
+{
        krb5_keyblock *skey = NULL;
        krb5_error_code err = 0;
        bool ret = false;
 
        if (remote) {
-               err = krb5_auth_con_getremotesubkey(context, auth_context, &skey);
+               err = krb5_auth_con_getremotesubkey(context,
+                                                   auth_context, &skey);
        } else {
-               err = krb5_auth_con_getlocalsubkey(context, auth_context, &skey);
+               err = krb5_auth_con_getlocalsubkey(context,
+                                                  auth_context, &skey);
        }
 
        if (err || skey == NULL) {
@@ -911,19 +1042,25 @@ failed:
                goto done;
        }
 
-       DEBUG(10, ("Got KRB5 session key of length %d\n",  (int)KRB5_KEY_LENGTH(skey)));
-       *session_key = data_blob(KRB5_KEY_DATA(skey), KRB5_KEY_LENGTH(skey));
-       dump_data_pw("KRB5 Session Key:\n", session_key->data, session_key->length);
+       DEBUG(10, ("Got KRB5 session key of length %d\n",
+                  (int)KRB5_KEY_LENGTH(skey)));
+
+       *session_key = data_blob_talloc(mem_ctx,
+                                        KRB5_KEY_DATA(skey),
+                                        KRB5_KEY_LENGTH(skey));
+       dump_data_pw("KRB5 Session Key:\n",
+                    session_key->data,
+                    session_key->length);
 
        ret = true;
 
- done:
+done:
        if (skey) {
                krb5_free_keyblock(context, skey);
        }
 
        return ret;
- }
+}
 
 
 #if defined(HAVE_KRB5_PRINCIPAL_GET_COMP_STRING) && !defined(HAVE_KRB5_PRINC_COMPONENT)
@@ -1845,128 +1982,6 @@ krb5_error_code smb_krb5_keytab_name(TALLOC_CTX *mem_ctx,
        return ret;
 }
 
-#if defined(TKT_FLG_OK_AS_DELEGATE ) && defined(HAVE_KRB5_FWD_TGT_CREDS) && defined(HAVE_KRB5_AUTH_CON_SET_REQ_CKSUMTYPE) && defined(KRB5_AUTH_CONTEXT_USE_SUBKEY)
-/**************************************************************
-Routine: ads_krb5_get_fwd_ticket
- Description:
-    When a service ticket is flagged as trusted
-    for delegation we should provide a forwardable
-    ticket so that the remote host can act on our
-    behalf.  This is done by taking the 2nd forwardable
-    TGT and storing it in the GSS-API authenticator
-    "checksum".  This routine will populate
-    the krb5_data authenticator with this TGT.
- Parameters:
-    krb5_context context: The kerberos context for this authentication.
-    krb5_auth_context:    The authentication context.
-    krb5_creds *credsp:   The ticket credentials (AS-REP).
-    krb5_ccache ccache:   The credentials cache.
-    krb5_data &authenticator: The checksum field that will store the TGT, and
-     authenticator.data must be freed by the caller.
-
- Returns:
-    krb5_error_code: 0 if no errors, otherwise set.
-**************************************************************/
-
-static krb5_error_code ads_krb5_get_fwd_ticket( krb5_context context,
-                                        krb5_auth_context *auth_context,
-                                        krb5_creds *credsp,
-                                        krb5_ccache ccache,
-                                        krb5_data *authenticator)
-{
-       krb5_data fwdData;
-       krb5_error_code retval = 0;
-       char *pChksum = NULL;
-       char *p = NULL;
-
-/* MIT krb5 1.7beta3 (in Ubuntu Karmic) is missing the prototype,
-   but still has the symbol */
-#if !HAVE_DECL_KRB5_AUTH_CON_SET_REQ_CKSUMTYPE
-krb5_error_code krb5_auth_con_set_req_cksumtype(  
-       krb5_context     context,
-       krb5_auth_context      auth_context,  
-       krb5_cksumtype     cksumtype);
-#endif
-
-       ZERO_STRUCT(fwdData);
-       ZERO_STRUCTP(authenticator);
-
-       retval = krb5_fwd_tgt_creds(context,/* Krb5 context [in] */
-                               *auth_context,  /* Authentication context [in] */
-                               CONST_DISCARD(char *, KRB5_TGS_NAME),  /* Ticket service name ("krbtgt") [in] */
-                               credsp->client, /* Client principal for the tgt [in] */
-                               credsp->server, /* Server principal for the tgt [in] */
-                               ccache,         /* Credential cache to use for storage [in] */
-                               1,              /* Turn on for "Forwardable ticket" [in] */
-                               &fwdData );     /* Resulting response [out] */
-
-
-       if (retval) {
-               DEBUG(1,("ads_krb5_get_fwd_ticket: krb5_fwd_tgt_creds failed (%s)\n", 
-                       error_message(retval)));
-               goto out;
-       }
-
-       if ((unsigned int)GSSAPI_CHECKSUM_SIZE + (unsigned int)fwdData.length <
-               (unsigned int)GSSAPI_CHECKSUM_SIZE) {
-               retval = EINVAL;
-               goto out;
-       }
-
-       /* We're going to allocate a gssChecksum structure with a little
-          extra data the length of the kerberos credentials length
-          (APPLICATION 22) so that we can pack it on the end of the structure.
-       */
-
-       pChksum = (char *)SMB_MALLOC(GSSAPI_CHECKSUM_SIZE + fwdData.length );
-       if (!pChksum) {
-               retval = ENOMEM;
-               goto out;
-       }
-
-       p = pChksum;
-
-       SIVAL(p, 0, GSSAPI_BNDLENGTH);
-       p += 4;
-
-       /* Zero out the bindings fields */
-       memset(p, '\0', GSSAPI_BNDLENGTH );
-       p += GSSAPI_BNDLENGTH;
-
-       SIVAL(p, 0, GSS_C_DELEG_FLAG );
-       p += 4;
-       SSVAL(p, 0, 1 );
-       p += 2;
-       SSVAL(p, 0, fwdData.length );
-       p += 2;
-
-       /* Migrate the kerberos KRB_CRED data to the checksum delegation */
-       memcpy(p, fwdData.data, fwdData.length );
-       p += fwdData.length;
-
-       /* We need to do this in order to allow our GSS-API  */
-       retval = krb5_auth_con_set_req_cksumtype( context, *auth_context, GSSAPI_CHECKSUM );
-       if (retval) {
-               goto out;
-       }
-
-       /* We now have a service ticket, now turn it into an AP-REQ. */
-       authenticator->length = fwdData.length + GSSAPI_CHECKSUM_SIZE;
-
-       /* Caller should call free() when they're done with this. */
-       authenticator->data = (char *)pChksum;
-
-  out:
-
-       /* Remove that input data, we never needed it anyway. */
-       if (fwdData.length > 0) {
-               krb5_free_data_contents( context, &fwdData );
-       }
-
-       return retval;
-}
-#endif
-
 #if defined(HAVE_KRB5_GET_CREDS_OPT_SET_IMPERSONATE) && \
     defined(HAVE_KRB5_GET_CREDS_OPT_ALLOC) && \
     defined(HAVE_KRB5_GET_CREDS)
@@ -2263,8 +2278,10 @@ char *smb_krb5_principal_get_realm(krb5_context context,
 
 #else /* HAVE_KRB5 */
  /* this saves a few linking headaches */
- int cli_krb5_get_ticket(const char *principal, time_t time_offset, 
-                       DATA_BLOB *ticket, DATA_BLOB *session_key_krb5, uint32 extra_ap_opts,
+ int cli_krb5_get_ticket(TALLOC_CTX *mem_ctx,
+                       const char *principal, time_t time_offset,
+                       DATA_BLOB *ticket, DATA_BLOB *session_key_krb5,
+                       uint32_t extra_ap_opts,
                        const char *ccname, time_t *tgs_expire,
                        const char *impersonate_princ_s)
 {
@@ -2272,4 +2289,10 @@ char *smb_krb5_principal_get_realm(krb5_context context,
         return 1;
 }
 
-#endif
+bool unwrap_pac(TALLOC_CTX *mem_ctx, DATA_BLOB *auth_data, DATA_BLOB *unwrapped_pac_data)
+{
+       DEBUG(0,("NO KERBEROS SUPPORT\n"));
+       return false;
+}
+
+#endif /* HAVE_KRB5 */