auth-krb: Move pac related util functions in a single place.
[kamenim/samba-autobuild/.git] / source4 / auth / kerberos / kerberos_pac.c
index 858f91045cb5a5e730ee1b2e0d2f195c64e07f2a..82a029871c6897087664f3c75720e764a7a527b0 100644 (file)
-/* 
+/*
    Unix SMB/CIFS implementation.
 
    Create and parse the krb5 PAC
-   
-   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004-2005
+
+   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004-2005,2008
    Copyright (C) Andrew Tridgell 2001
    Copyright (C) Luke Howard 2002-2003
    Copyright (C) Stefan Metzmacher 2004-2005
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 2 of the License, or
+   the Free Software Foundation; either version 3 of the License, or
    (at your option) any later version.
-   
+
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
 
-   
+
    You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software
-   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
 #include "includes.h"
 #include "system/kerberos.h"
-#include "system/time.h"
-#include "system/network.h"
 #include "auth/auth.h"
 #include "auth/kerberos/kerberos.h"
 #include "librpc/gen_ndr/ndr_krb5pac.h"
-#include "auth/auth.h"
+#include <ldb.h>
+#include "auth/auth_sam_reply.h"
+#include "auth/kerberos/kerberos_util.h"
+#include "auth/kerberos/pac_utils.h"
+
+_PUBLIC_  NTSTATUS kerberos_pac_logon_info(TALLOC_CTX *mem_ctx,
+                                          DATA_BLOB blob,
+                                          krb5_context context,
+                                          const krb5_keyblock *krbtgt_keyblock,
+                                          const krb5_keyblock *service_keyblock,
+                                          krb5_const_principal client_principal,
+                                          time_t tgs_authtime,
+                                          struct PAC_LOGON_INFO **logon_info)
+{
+       NTSTATUS nt_status;
+       struct PAC_DATA *pac_data;
+       int i;
+       nt_status = kerberos_decode_pac(mem_ctx,
+                                       blob,
+                                       context,
+                                       krbtgt_keyblock,
+                                       service_keyblock,
+                                       client_principal,
+                                       tgs_authtime,
+                                       &pac_data);
+       if (!NT_STATUS_IS_OK(nt_status)) {
+               return nt_status;
+       }
+
+       *logon_info = NULL;
+       for (i=0; i < pac_data->num_buffers; i++) {
+               if (pac_data->buffers[i].type != PAC_TYPE_LOGON_INFO) {
+                       continue;
+               }
+               *logon_info = pac_data->buffers[i].info->logon_info.info;
+       }
+       if (!*logon_info) {
+               return NT_STATUS_INVALID_PARAMETER;
+       }
+       return NT_STATUS_OK;
+}
 
-static NTSTATUS check_pac_checksum(TALLOC_CTX *mem_ctx, 
-                                  DATA_BLOB pac_data,
-                                  struct PAC_SIGNATURE_DATA *sig,
-                                  krb5_context context,
-                                  krb5_keyblock *keyblock)
+static krb5_error_code make_pac_checksum(TALLOC_CTX *mem_ctx,
+                                        DATA_BLOB *pac_data,
+                                        struct PAC_SIGNATURE_DATA *sig,
+                                        krb5_context context,
+                                        const krb5_keyblock *keyblock)
 {
        krb5_error_code ret;
        krb5_crypto crypto;
        Checksum cksum;
 
-       cksum.cksumtype         = (CKSUMTYPE)sig->type;
-       cksum.checksum.length   = sizeof(sig->signature);
-       cksum.checksum.data     = sig->signature;
-
 
        ret = krb5_crypto_init(context,
                               keyblock,
                               0,
                               &crypto);
        if (ret) {
-               DEBUG(0,("krb5_crypto_init() failed: %s\n", 
+               DEBUG(0,("krb5_crypto_init() failed: %s\n",
                          smb_get_krb5_error_message(context, ret, mem_ctx)));
-               return NT_STATUS_FOOBAR;
+               return ret;
        }
-       ret = krb5_verify_checksum(context,
+       ret = krb5_create_checksum(context,
                                   crypto,
                                   KRB5_KU_OTHER_CKSUM,
-                                  pac_data.data,
-                                  pac_data.length,
+                                  0,
+                                  pac_data->data,
+                                  pac_data->length,
                                   &cksum);
        if (ret) {
-               DEBUG(2, ("PAC Verification failed: %s\n", 
+               DEBUG(2, ("PAC Verification failed: %s\n",
                          smb_get_krb5_error_message(context, ret, mem_ctx)));
        }
 
        krb5_crypto_destroy(context, crypto);
 
        if (ret) {
-               return NT_STATUS_ACCESS_DENIED;
+               return ret;
        }
 
-       return NT_STATUS_OK;
+       sig->type = cksum.cksumtype;
+       sig->signature = data_blob_talloc(mem_ctx, cksum.checksum.data, cksum.checksum.length);
+       free_Checksum(&cksum);
+
+       return 0;
 }
 
NTSTATUS kerberos_decode_pac(TALLOC_CTX *mem_ctx,
-                             struct PAC_LOGON_INFO **logon_info_out,
-                             DATA_BLOB blob,
-                             struct smb_krb5_context *smb_krb5_context,
-                             krb5_keyblock *krbtgt_keyblock,
-                             krb5_keyblock *service_keyblock)
krb5_error_code kerberos_encode_pac(TALLOC_CTX *mem_ctx,
+                                   struct PAC_DATA *pac_data,
+                                   krb5_context context,
+                                   const krb5_keyblock *krbtgt_keyblock,
+                                   const krb5_keyblock *service_keyblock,
+                                   DATA_BLOB *pac)
 {
-       NTSTATUS status;
-       struct PAC_SIGNATURE_DATA srv_sig;
-       struct PAC_SIGNATURE_DATA *srv_sig_ptr = NULL;
-       struct PAC_SIGNATURE_DATA kdc_sig;
-       struct PAC_SIGNATURE_DATA *kdc_sig_ptr = NULL;
-       struct PAC_LOGON_INFO *logon_info = NULL;
-       struct PAC_DATA pac_data;
-       DATA_BLOB modified_pac_blob = data_blob_talloc(mem_ctx, blob.data, blob.length);
+       NTSTATUS nt_status;
+       krb5_error_code ret;
+       enum ndr_err_code ndr_err;
+       DATA_BLOB zero_blob = data_blob(NULL, 0);
+       DATA_BLOB tmp_blob = data_blob(NULL, 0);
+       struct PAC_SIGNATURE_DATA *kdc_checksum = NULL;
+       struct PAC_SIGNATURE_DATA *srv_checksum = NULL;
        int i;
 
-       /* file_save("tmp_pac_data.dat",blob.data,blob.length); */
-
-       status = ndr_pull_struct_blob(&blob, mem_ctx, &pac_data,
-                                       (ndr_pull_flags_fn_t)ndr_pull_PAC_DATA);
-       if (!NT_STATUS_IS_OK(status)) {
-               DEBUG(0,("can't parse the PAC\n"));
-               return status;
-       }
-
-       if (pac_data.num_buffers < 3) {
-               /* we need logon_ingo, service_key and kdc_key */
-               DEBUG(0,("less than 3 PAC buffers\n"));
-               return NT_STATUS_FOOBAR;
-       }
-
-       for (i=0; i < pac_data.num_buffers; i++) {
-               switch (pac_data.buffers[i].type) {
-                       case PAC_TYPE_LOGON_INFO:
-                               if (!pac_data.buffers[i].info) {
-                                       break;
-                               }
-                               logon_info = pac_data.buffers[i].info->logon_info.info;
-                               break;
-                       case PAC_TYPE_SRV_CHECKSUM:
-                               if (!pac_data.buffers[i].info) {
-                                       break;
-                               }
-                               srv_sig_ptr = &pac_data.buffers[i].info->srv_cksum;
-                               srv_sig = pac_data.buffers[i].info->srv_cksum;
-                               break;
-                       case PAC_TYPE_KDC_CHECKSUM:
-                               if (!pac_data.buffers[i].info) {
-                                       break;
-                               }
-                               kdc_sig_ptr = &pac_data.buffers[i].info->kdc_cksum;
-                               kdc_sig = pac_data.buffers[i].info->kdc_cksum;
-                               break;
-                       case PAC_TYPE_LOGON_NAME:
-                               break;
-                       default:
-                               break;
+       /* First, just get the keytypes filled in (and lengths right, eventually) */
+       for (i=0; i < pac_data->num_buffers; i++) {
+               if (pac_data->buffers[i].type != PAC_TYPE_KDC_CHECKSUM) {
+                       continue;
+               }
+               kdc_checksum = &pac_data->buffers[i].info->kdc_cksum,
+               ret = make_pac_checksum(mem_ctx, &zero_blob,
+                                       kdc_checksum,
+                                       context, krbtgt_keyblock);
+               if (ret) {
+                       DEBUG(2, ("making krbtgt PAC checksum failed: %s\n",
+                                 smb_get_krb5_error_message(context, ret, mem_ctx)));
+                       talloc_free(pac_data);
+                       return ret;
                }
        }
 
-       if (!logon_info) {
-               DEBUG(0,("PAC no logon_info\n"));
-               return NT_STATUS_FOOBAR;
-       }
-
-       if (!srv_sig_ptr) {
-               DEBUG(0,("PAC no srv_key\n"));
-               return NT_STATUS_FOOBAR;
+       for (i=0; i < pac_data->num_buffers; i++) {
+               if (pac_data->buffers[i].type != PAC_TYPE_SRV_CHECKSUM) {
+                       continue;
+               }
+               srv_checksum = &pac_data->buffers[i].info->srv_cksum;
+               ret = make_pac_checksum(mem_ctx, &zero_blob,
+                                       srv_checksum,
+                                       context, service_keyblock);
+               if (ret) {
+                       DEBUG(2, ("making service PAC checksum failed: %s\n",
+                                 smb_get_krb5_error_message(context, ret, mem_ctx)));
+                       talloc_free(pac_data);
+                       return ret;
+               }
        }
 
-       if (!kdc_sig_ptr) {
-               DEBUG(0,("PAC no kdc_key\n"));
-               return NT_STATUS_FOOBAR;
+       if (!kdc_checksum) {
+               DEBUG(2, ("Invalid PAC constructed for signing, no KDC checksum present!"));
+               return EINVAL;
        }
-
-       memset(&modified_pac_blob.data[modified_pac_blob.length - 20],
-              '\0', 16);
-       memset(&modified_pac_blob.data[modified_pac_blob.length - 44],
-              '\0', 16);
-
-       /* verify by service_key */
-       status = check_pac_checksum(mem_ctx, 
-                                   modified_pac_blob, &srv_sig, 
-                                   smb_krb5_context->krb5_context, 
-                                   service_keyblock);
-       if (!NT_STATUS_IS_OK(status)) {
-               DEBUG(1, ("PAC Decode: Failed to verify the service signature\n"));
-               return status;
+       if (!srv_checksum) {
+               DEBUG(2, ("Invalid PAC constructed for signing, no SRV checksum present!"));
+               return EINVAL;
        }
 
-       if (krbtgt_keyblock) {
-               DATA_BLOB service_checksum_blob
-                       = data_blob(srv_sig_ptr->signature, sizeof(srv_sig_ptr->signature));
-
-               status = check_pac_checksum(mem_ctx, 
-                                           service_checksum_blob, &kdc_sig, 
-                                           smb_krb5_context->krb5_context, krbtgt_keyblock);
-               if (!NT_STATUS_IS_OK(status)) {
-                       DEBUG(1, ("PAC Decode: Failed to verify the krbtgt signature\n"));
-                       return status;
-               }
+       /* But wipe out the actual signatures */
+       memset(kdc_checksum->signature.data, '\0', kdc_checksum->signature.length);
+       memset(srv_checksum->signature.data, '\0', srv_checksum->signature.length);
+
+       ndr_err = ndr_push_struct_blob(&tmp_blob, mem_ctx,
+                                      pac_data,
+                                      (ndr_push_flags_fn_t)ndr_push_PAC_DATA);
+       if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+               nt_status = ndr_map_error2ntstatus(ndr_err);
+               DEBUG(1, ("PAC (presig) push failed: %s\n", nt_errstr(nt_status)));
+               talloc_free(pac_data);
+               return EINVAL;
        }
 
-       DEBUG(0,("account_name: %s [%s]\n",
-                logon_info->info3.base.account_name.string, 
-                logon_info->info3.base.full_name.string));
-       *logon_info_out = logon_info;
-
-       return status;
-}
-
-static krb5_error_code make_pac_checksum(TALLOC_CTX *mem_ctx, 
-                                        DATA_BLOB pac_data,
-                                        struct PAC_SIGNATURE_DATA *sig,
-                                        krb5_context context,
-                                        krb5_keyblock *keyblock)
-{
-       krb5_error_code ret;
-       krb5_crypto crypto;
-       Checksum cksum;
-
+       /* Then sign the result of the previous push, where the sig was zero'ed out */
+       ret = make_pac_checksum(mem_ctx, &tmp_blob, srv_checksum,
+                               context, service_keyblock);
 
-       ret = krb5_crypto_init(context,
-                              keyblock,
-                              0,
-                              &crypto);
-       if (ret) {
-               DEBUG(0,("krb5_crypto_init() failed\n"));
-               return ret;
-       }
-       ret = krb5_create_checksum(context,
-                                  crypto,
-                                  KRB5_KU_OTHER_CKSUM,
-                                  0,
-                                  pac_data.data,
-                                  pac_data.length,
-                                  &cksum);
+       /* Then sign Server checksum */
+       ret = make_pac_checksum(mem_ctx, &srv_checksum->signature, kdc_checksum, context, krbtgt_keyblock);
        if (ret) {
-               DEBUG(2, ("PAC Verification failed: %s\n", 
+               DEBUG(2, ("making krbtgt PAC checksum failed: %s\n",
                          smb_get_krb5_error_message(context, ret, mem_ctx)));
-       }
-
-       krb5_crypto_destroy(context, crypto);
-
-       if (ret) {
+               talloc_free(pac_data);
                return ret;
        }
 
-       sig->type = cksum.cksumtype;
-       if (cksum.checksum.length == sizeof(sig->signature)) {
-               memcpy(sig->signature, cksum.checksum.data, sizeof(sig->signature));
+       /* And push it out again, this time to the world.  This relies on determanistic pointer values */
+       ndr_err = ndr_push_struct_blob(&tmp_blob, mem_ctx,
+                                      pac_data,
+                                      (ndr_push_flags_fn_t)ndr_push_PAC_DATA);
+       if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+               nt_status = ndr_map_error2ntstatus(ndr_err);
+               DEBUG(1, ("PAC (final) push failed: %s\n", nt_errstr(nt_status)));
+               talloc_free(pac_data);
+               return EINVAL;
        }
 
-       return 0;
+       *pac = tmp_blob;
+
+       return ret;
 }
 
- krb5_error_code kerberos_encode_pac(TALLOC_CTX *mem_ctx,
-                                    struct auth_serversupplied_info *server_info,
+
+ krb5_error_code kerberos_create_pac(TALLOC_CTX *mem_ctx,
+                                    struct auth_user_info_dc *user_info_dc,
                                     krb5_context context,
-                                    krb5_keyblock *krbtgt_keyblock,
-                                    krb5_keyblock *service_keyblock,
+                                    const krb5_keyblock *krbtgt_keyblock,
+                                    const krb5_keyblock *service_keyblock,
+                                    krb5_principal client_principal,
+                                    time_t tgs_authtime,
                                     DATA_BLOB *pac)
 {
        NTSTATUS nt_status;
-       DATA_BLOB zero_blob = data_blob(NULL, 0);
-       DATA_BLOB tmp_blob = data_blob(NULL, 0);
-       DATA_BLOB service_checksum_blob;
        krb5_error_code ret;
        struct PAC_DATA *pac_data = talloc(mem_ctx, struct PAC_DATA);
        struct netr_SamInfo3 *sam3;
-       struct timeval tv = timeval_current();
        union PAC_INFO *u_LOGON_INFO;
        struct PAC_LOGON_INFO *LOGON_INFO;
        union PAC_INFO *u_LOGON_NAME;
        struct PAC_LOGON_NAME *LOGON_NAME;
        union PAC_INFO *u_KDC_CHECKSUM;
-       struct PAC_SIGNATURE_DATA *KDC_CHECKSUM;
        union PAC_INFO *u_SRV_CHECKSUM;
-       struct PAC_SIGNATURE_DATA *SRV_CHECKSUM;
+
+       char *name;
 
        enum {
                PAC_BUF_LOGON_INFO = 0,
@@ -273,7 +254,7 @@ static krb5_error_code make_pac_checksum(TALLOC_CTX *mem_ctx,
        pac_data->num_buffers = PAC_BUF_NUM_BUFFERS;
        pac_data->version = 0;
 
-       pac_data->buffers = talloc_array(pac_data, 
+       pac_data->buffers = talloc_array(pac_data,
                                         struct PAC_BUFFER,
                                         pac_data->num_buffers);
        if (!pac_data->buffers) {
@@ -308,7 +289,6 @@ static krb5_error_code make_pac_checksum(TALLOC_CTX *mem_ctx,
        }
        pac_data->buffers[PAC_BUF_SRV_CHECKSUM].type = PAC_TYPE_SRV_CHECKSUM;
        pac_data->buffers[PAC_BUF_SRV_CHECKSUM].info = u_SRV_CHECKSUM;
-       SRV_CHECKSUM = &u_SRV_CHECKSUM->srv_cksum;
 
        /* KDC_CHECKSUM */
        u_KDC_CHECKSUM = talloc_zero(pac_data->buffers, union PAC_INFO);
@@ -318,7 +298,6 @@ static krb5_error_code make_pac_checksum(TALLOC_CTX *mem_ctx,
        }
        pac_data->buffers[PAC_BUF_KDC_CHECKSUM].type = PAC_TYPE_KDC_CHECKSUM;
        pac_data->buffers[PAC_BUF_KDC_CHECKSUM].info = u_KDC_CHECKSUM;
-       KDC_CHECKSUM = &u_KDC_CHECKSUM->kdc_cksum;
 
        /* now the real work begins... */
 
@@ -327,7 +306,7 @@ static krb5_error_code make_pac_checksum(TALLOC_CTX *mem_ctx,
                talloc_free(pac_data);
                return ENOMEM;
        }
-       nt_status = auth_convert_server_info_saminfo3(LOGON_INFO, server_info, &sam3);
+       nt_status = auth_convert_user_info_dc_saminfo3(LOGON_INFO, user_info_dc, &sam3);
        if (!NT_STATUS_IS_OK(nt_status)) {
                DEBUG(1, ("Getting Samba info failed: %s\n", nt_errstr(nt_status)));
                talloc_free(pac_data);
@@ -336,70 +315,149 @@ static krb5_error_code make_pac_checksum(TALLOC_CTX *mem_ctx,
 
        u_LOGON_INFO->logon_info.info           = LOGON_INFO;
        LOGON_INFO->info3 = *sam3;
-       LOGON_INFO->info3.base.last_logon       = timeval_to_nttime(&tv);
 
-       LOGON_NAME->account_name        = server_info->account_name;
-       LOGON_NAME->logon_time          = timeval_to_nttime(&tv);
+       ret = krb5_unparse_name_flags(context, client_principal,
+                                     KRB5_PRINCIPAL_UNPARSE_NO_REALM, &name);
+       if (ret) {
+               return ret;
+       }
+       LOGON_NAME->account_name        = talloc_strdup(LOGON_NAME, name);
+       free(name);
+       /*
+         this logon_time field is absolutely critical. This is what
+         caused all our PAC troubles :-)
+       */
+       unix_to_nt_time(&LOGON_NAME->logon_time, tgs_authtime);
+
+       ret = kerberos_encode_pac(mem_ctx,
+                                 pac_data,
+                                 context,
+                                 krbtgt_keyblock,
+                                 service_keyblock,
+                                 pac);
+       talloc_free(pac_data);
+       return ret;
+}
 
+krb5_error_code kerberos_pac_to_user_info_dc(TALLOC_CTX *mem_ctx,
+                                            krb5_pac pac,
+                                            krb5_context context,
+                                            struct auth_user_info_dc **user_info_dc,
+                                            struct PAC_SIGNATURE_DATA *pac_srv_sig,
+                                            struct PAC_SIGNATURE_DATA *pac_kdc_sig)
+{
+       NTSTATUS nt_status;
+       enum ndr_err_code ndr_err;
+       krb5_error_code ret;
 
+       DATA_BLOB pac_logon_info_in, pac_srv_checksum_in, pac_kdc_checksum_in;
+       krb5_data k5pac_logon_info_in, k5pac_srv_checksum_in, k5pac_kdc_checksum_in;
 
-       /* First, just get the keytypes filled in (and lengths right, eventually) */
-       ret = make_pac_checksum(mem_ctx, zero_blob, KDC_CHECKSUM, context, krbtgt_keyblock);
-       if (ret) {
-               DEBUG(2, ("making krbtgt PAC checksum failed: %s\n", 
-                         smb_get_krb5_error_message(context, ret, mem_ctx)));
-               talloc_free(pac_data);
-               return ret;
+       union PAC_INFO info;
+       struct auth_user_info_dc *user_info_dc_out;
+
+       TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
+
+       if (!tmp_ctx) {
+               return ENOMEM;
        }
 
-       ret = make_pac_checksum(mem_ctx, zero_blob, SRV_CHECKSUM, context, service_keyblock);
-       if (ret) {
-               DEBUG(2, ("making service PAC checksum failed: %s\n", 
-                         smb_get_krb5_error_message(context, ret, mem_ctx)));
-               talloc_free(pac_data);
-               return ret;
+       ret = krb5_pac_get_buffer(context, pac, PAC_TYPE_LOGON_INFO, &k5pac_logon_info_in);
+       if (ret != 0) {
+               talloc_free(tmp_ctx);
+               return EINVAL;
        }
 
-       /* But wipe out the actual signatures */
-       ZERO_STRUCT(KDC_CHECKSUM->signature);
-       ZERO_STRUCT(SRV_CHECKSUM->signature);
+       pac_logon_info_in = data_blob_const(k5pac_logon_info_in.data, k5pac_logon_info_in.length);
+
+       ndr_err = ndr_pull_union_blob(&pac_logon_info_in, tmp_ctx, &info,
+                                     PAC_TYPE_LOGON_INFO,
+                                     (ndr_pull_flags_fn_t)ndr_pull_PAC_INFO);
+       krb5_data_free(&k5pac_logon_info_in);
+       if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err) || !info.logon_info.info) {
+               nt_status = ndr_map_error2ntstatus(ndr_err);
+               DEBUG(0,("can't parse the PAC LOGON_INFO: %s\n", nt_errstr(nt_status)));
+               talloc_free(tmp_ctx);
+               return EINVAL;
+       }
 
-       nt_status = ndr_push_struct_blob(&tmp_blob, mem_ctx, pac_data,
-                                        (ndr_push_flags_fn_t)ndr_push_PAC_DATA);
+       /* Pull this right into the normal auth sysstem structures */
+       nt_status = make_user_info_dc_pac(mem_ctx,
+                                        info.logon_info.info,
+                                        &user_info_dc_out);
        if (!NT_STATUS_IS_OK(nt_status)) {
-               DEBUG(1, ("PAC (presig) push failed: %s\n", nt_errstr(nt_status)));
-               talloc_free(pac_data);
+               talloc_free(tmp_ctx);
                return EINVAL;
        }
 
-       /* Then sign the result of the previous push, where the sig was zero'ed out */
-       ret = make_pac_checksum(mem_ctx, tmp_blob, SRV_CHECKSUM,
-                               context, service_keyblock);
+       if (pac_srv_sig) {
+               ret = krb5_pac_get_buffer(context, pac, PAC_TYPE_SRV_CHECKSUM, &k5pac_srv_checksum_in);
+               if (ret != 0) {
+                       talloc_free(tmp_ctx);
+                       return ret;
+               }
 
-       service_checksum_blob
-               = data_blob(SRV_CHECKSUM->signature, sizeof(SRV_CHECKSUM->signature));
+               pac_srv_checksum_in = data_blob_const(k5pac_srv_checksum_in.data, k5pac_srv_checksum_in.length);
+
+               ndr_err = ndr_pull_struct_blob(&pac_srv_checksum_in, pac_srv_sig,
+                                              pac_srv_sig,
+                                              (ndr_pull_flags_fn_t)ndr_pull_PAC_SIGNATURE_DATA);
+               krb5_data_free(&k5pac_srv_checksum_in);
+               if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+                       nt_status = ndr_map_error2ntstatus(ndr_err);
+                       DEBUG(0,("can't parse the KDC signature: %s\n",
+                                nt_errstr(nt_status)));
+                       return EINVAL;
+               }
+       }
 
-       /* Then sign Server checksum */
-       ret = make_pac_checksum(mem_ctx, service_checksum_blob, KDC_CHECKSUM, context, krbtgt_keyblock);
-       if (ret) {
-               DEBUG(2, ("making krbtgt PAC checksum failed: %s\n", 
-                         smb_get_krb5_error_message(context, ret, mem_ctx)));
-               talloc_free(pac_data);
-               return ret;
+       if (pac_kdc_sig) {
+               ret = krb5_pac_get_buffer(context, pac, PAC_TYPE_KDC_CHECKSUM, &k5pac_kdc_checksum_in);
+               if (ret != 0) {
+                       talloc_free(tmp_ctx);
+                       return ret;
+               }
+
+               pac_kdc_checksum_in = data_blob_const(k5pac_kdc_checksum_in.data, k5pac_kdc_checksum_in.length);
+
+               ndr_err = ndr_pull_struct_blob(&pac_kdc_checksum_in, pac_kdc_sig,
+                                              pac_kdc_sig,
+                                              (ndr_pull_flags_fn_t)ndr_pull_PAC_SIGNATURE_DATA);
+               krb5_data_free(&k5pac_kdc_checksum_in);
+               if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+                       nt_status = ndr_map_error2ntstatus(ndr_err);
+                       DEBUG(0,("can't parse the KDC signature: %s\n",
+                                nt_errstr(nt_status)));
+                       return EINVAL;
+               }
        }
+       *user_info_dc = user_info_dc_out;
 
-       /* And push it out again, this time to the world.  This relies on determanistic pointer values */
-       nt_status = ndr_push_struct_blob(&tmp_blob, mem_ctx, pac_data,
-                                        (ndr_push_flags_fn_t)ndr_push_PAC_DATA);
-       if (!NT_STATUS_IS_OK(nt_status)) {
-               DEBUG(1, ("PAC (final) push failed: %s\n", nt_errstr(nt_status)));
-               talloc_free(pac_data);
-               return EINVAL;
+       return 0;
+}
+
+
+NTSTATUS kerberos_pac_blob_to_user_info_dc(TALLOC_CTX *mem_ctx,
+                                          DATA_BLOB pac_blob,
+                                          krb5_context context,
+                                          struct auth_user_info_dc **user_info_dc,
+                                          struct PAC_SIGNATURE_DATA *pac_srv_sig,
+                                          struct PAC_SIGNATURE_DATA *pac_kdc_sig)
+{
+       krb5_error_code ret;
+       krb5_pac pac;
+       ret = krb5_pac_parse(context,
+                            pac_blob.data, pac_blob.length,
+                            &pac);
+       if (ret) {
+               return map_nt_error_from_unix_common(ret);
        }
 
-       *pac = tmp_blob;
 
-       talloc_free(pac_data);
-       return ret;
+       ret = kerberos_pac_to_user_info_dc(mem_ctx, pac, context, user_info_dc, pac_srv_sig, pac_kdc_sig);
+       krb5_pac_free(context, pac);
+       if (ret) {
+               return map_nt_error_from_unix_common(ret);
+       }
+       return NT_STATUS_OK;
 }
-