Heimdal provides Kerberos PAC parsing routines. Use them.
[metze/samba/wip.git] / source / auth / kerberos / kerberos_pac.c
index 84a7c56cc98b25cfcc4df8943d9071484e0c411d..9ebace32cb5b188675a9821177b75150be95772f 100644 (file)
@@ -1,16 +1,16 @@
 /* 
    Unix SMB/CIFS implementation.
 
-   Kerberos backend for GENSEC
+   Create and parse the krb5 PAC
    
-   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004
+   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,
 
    
    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 "lib/ldb/include/ldb.h"
+#include "auth/auth_sam_reply.h"
+#include "param/param.h"
 
-static NTSTATUS kerberos_pac_checksum(TALLOC_CTX *mem_ctx, 
-                                     DATA_BLOB pac_data,
-                                     struct PAC_SIGNATURE_DATA *sig,
-                                     struct smb_krb5_context *smb_krb5_context,
-                                     krb5_keyblock *keyblock,
-                                     uint32_t keyusage)
+static krb5_error_code check_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;
-       int i;
 
        cksum.cksumtype         = (CKSUMTYPE)sig->type;
-       cksum.checksum.length   = sizeof(sig->signature);
-       cksum.checksum.data     = sig->signature;
+       cksum.checksum.length   = sig->signature.length;
+       cksum.checksum.data     = sig->signature.data;
 
-
-       ret = krb5_crypto_init(smb_krb5_context->krb5_context,
+       ret = krb5_crypto_init(context,
                               keyblock,
                               0,
                               &crypto);
        if (ret) {
-               DEBUG(0,("krb5_crypto_init() failed\n"));
-               return NT_STATUS_FOOBAR;
-       }
-       for (i=0; i < 40; i++) {
-               keyusage = i;
-               ret = krb5_verify_checksum(smb_krb5_context->krb5_context,
-                                          crypto,
-                                          keyusage,
-                                          pac_data.data,
-                                          pac_data.length,
-                                          &cksum);
-               if (!ret) {
-                       DEBUG(0, ("PAC Verified: keyusage: %d\n", keyusage));
-                       break;
-               } else {
-                       DEBUG(2, ("PAC Verification failed: %s\n", 
-                                 smb_get_krb5_error_message(smb_krb5_context->krb5_context, ret, mem_ctx)));
-               }
+               DEBUG(0,("krb5_crypto_init() failed: %s\n", 
+                         smb_get_krb5_error_message(context, ret, mem_ctx)));
+               return ret;
        }
+       ret = krb5_verify_checksum(context,
+                                  crypto,
+                                  KRB5_KU_OTHER_CKSUM,
+                                  pac_data.data,
+                                  pac_data.length,
+                                  &cksum);
+       krb5_crypto_destroy(context, crypto);
 
-       krb5_crypto_destroy(smb_krb5_context->krb5_context, crypto);
-
-       if (ret) {
-               DEBUG(0,("NOT verifying PAC checksums yet!\n"));
-               //return NT_STATUS_LOGON_FAILURE;
-       } else {
-               DEBUG(0,("PAC checksums verified!\n"));
-       }
-
-       return NT_STATUS_OK;
+       return ret;
 }
 
  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 *keyblock)
+                             struct smb_iconv_convenience *iconv_convenience,
+                             struct PAC_DATA **pac_data_out,
+                             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,
+                             krb5_error_code *k5ret)
 {
+       krb5_error_code ret;
        NTSTATUS status;
-       struct PAC_SIGNATURE_DATA srv_sig;
+       enum ndr_err_code ndr_err;
        struct PAC_SIGNATURE_DATA *srv_sig_ptr = NULL;
-       struct PAC_SIGNATURE_DATA kdc_sig;
        struct PAC_SIGNATURE_DATA *kdc_sig_ptr = NULL;
+       struct PAC_SIGNATURE_DATA *srv_sig_wipe = NULL;
+       struct PAC_SIGNATURE_DATA *kdc_sig_wipe = 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);
-       DATA_BLOB tmp_blob;
+       struct PAC_LOGON_NAME *logon_name = NULL;
+       struct PAC_DATA *pac_data;
+       struct PAC_DATA_RAW *pac_data_raw;
+
+       DATA_BLOB *srv_sig_blob = NULL;
+       DATA_BLOB *kdc_sig_blob = NULL;
+
+       DATA_BLOB modified_pac_blob;
+       NTTIME tgs_authtime_nttime;
+       krb5_principal client_principal_pac;
        int i;
 
-       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"));
+       krb5_clear_error_string(context);
+
+       if (k5ret) {
+               *k5ret = KRB5_PARSE_MALFORMED;
+       }
+
+       pac_data = talloc(mem_ctx, struct PAC_DATA);
+       pac_data_raw = talloc(mem_ctx, struct PAC_DATA_RAW);
+       kdc_sig_wipe = talloc(mem_ctx, struct PAC_SIGNATURE_DATA);
+       srv_sig_wipe = talloc(mem_ctx, struct PAC_SIGNATURE_DATA);
+       if (!pac_data_raw || !pac_data || !kdc_sig_wipe || !srv_sig_wipe) {
+               if (k5ret) {
+                       *k5ret = ENOMEM;
+               }
+               return NT_STATUS_NO_MEMORY;
+       }
+
+       ndr_err = ndr_pull_struct_blob(&blob, pac_data, 
+                       iconv_convenience, pac_data,
+                      (ndr_pull_flags_fn_t)ndr_pull_PAC_DATA);
+       if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+               status = ndr_map_error2ntstatus(ndr_err);
+               DEBUG(0,("can't parse the PAC: %s\n",
+                       nt_errstr(status)));
+               return status;
+       }
+
+       if (pac_data->num_buffers < 4) {
+               /* we need logon_ingo, service_key and kdc_key */
+               DEBUG(0,("less than 4 PAC buffers\n"));
+               return NT_STATUS_INVALID_PARAMETER;
+       }
+
+       ndr_err = ndr_pull_struct_blob(&blob, pac_data_raw, 
+                                      iconv_convenience, pac_data_raw,
+                                      (ndr_pull_flags_fn_t)ndr_pull_PAC_DATA_RAW);
+       if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+               status = ndr_map_error2ntstatus(ndr_err);
+               DEBUG(0,("can't parse the PAC: %s\n",
+                       nt_errstr(status)));
                return status;
        }
-       NDR_PRINT_DEBUG(PAC_DATA, &pac_data);
 
-       if (pac_data.num_buffers < 3) {
+       if (pac_data_raw->num_buffers < 4) {
+               /* we need logon_ingo, service_key and kdc_key */
+               DEBUG(0,("less than 4 PAC buffers\n"));
+               return NT_STATUS_INVALID_PARAMETER;
+       }
+
+       if (pac_data->num_buffers != pac_data_raw->num_buffers) {
                /* we need logon_ingo, service_key and kdc_key */
-               DEBUG(0,("less than 3 PAC buffers\n"));
-               return NT_STATUS_FOOBAR;
+               DEBUG(0,("misparse!  PAC_DATA has %d buffers while PAC_DATA_RAW has %d\n",
+                        pac_data->num_buffers, pac_data_raw->num_buffers));
+               return NT_STATUS_INVALID_PARAMETER;
        }
 
-       for (i=0; i < pac_data.num_buffers; i++) {
-               switch (pac_data.buffers[i].type) {
+       for (i=0; i < pac_data->num_buffers; i++) {
+               if (pac_data->buffers[i].type != pac_data_raw->buffers[i].type) {
+                       DEBUG(0,("misparse!  PAC_DATA buffer %d has type %d while PAC_DATA_RAW has %d\n",
+                                i, pac_data->buffers[i].type, pac_data->buffers[i].type));
+                       return NT_STATUS_INVALID_PARAMETER;
+               }
+               switch (pac_data->buffers[i].type) {
                        case PAC_TYPE_LOGON_INFO:
-                               if (!pac_data.buffers[i].info) {
+                               if (!pac_data->buffers[i].info) {
                                        break;
                                }
-                               logon_info = &pac_data.buffers[i].info->logon_info;
+                               logon_info = pac_data->buffers[i].info->logon_info.info;
                                break;
                        case PAC_TYPE_SRV_CHECKSUM:
-                               if (!pac_data.buffers[i].info) {
+                               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;
+                               srv_sig_ptr = &pac_data->buffers[i].info->srv_cksum;
+                               srv_sig_blob = &pac_data_raw->buffers[i].info->remaining;
                                break;
                        case PAC_TYPE_KDC_CHECKSUM:
-                               if (!pac_data.buffers[i].info) {
+                               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;
+                               kdc_sig_ptr = &pac_data->buffers[i].info->kdc_cksum;
+                               kdc_sig_blob = &pac_data_raw->buffers[i].info->remaining;
                                break;
-                       case PAC_TYPE_UNKNOWN_10:
+                       case PAC_TYPE_LOGON_NAME:
+                               logon_name = &pac_data->buffers[i].info->logon_name;
                                break;
                        default:
                                break;
@@ -148,43 +190,588 @@ static NTSTATUS kerberos_pac_checksum(TALLOC_CTX *mem_ctx,
 
        if (!logon_info) {
                DEBUG(0,("PAC no logon_info\n"));
-               return NT_STATUS_FOOBAR;
+               return NT_STATUS_INVALID_PARAMETER;
+       }
+
+       if (!logon_name) {
+               DEBUG(0,("PAC no logon_name\n"));
+               return NT_STATUS_INVALID_PARAMETER;
        }
 
-       if (!srv_sig_ptr) {
+       if (!srv_sig_ptr || !srv_sig_blob) {
                DEBUG(0,("PAC no srv_key\n"));
-               return NT_STATUS_FOOBAR;
+               return NT_STATUS_INVALID_PARAMETER;
        }
 
-       if (!kdc_sig_ptr) {
+       if (!kdc_sig_ptr || !kdc_sig_blob) {
                DEBUG(0,("PAC no kdc_key\n"));
-               return NT_STATUS_FOOBAR;
+               return NT_STATUS_INVALID_PARAMETER;
        }
 
-       memset(&modified_pac_blob.data[modified_pac_blob.length - 48],
-              '\0', 48);
+       /* Find and zero out the signatures, as required by the signing algorithm */
 
-       status = ndr_pull_struct_blob(&modified_pac_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"));
+       /* We find the data blobs above, now we parse them to get at the exact portion we should zero */
+       ndr_err = ndr_pull_struct_blob(kdc_sig_blob, kdc_sig_wipe, 
+                                      iconv_convenience, kdc_sig_wipe,
+                                      (ndr_pull_flags_fn_t)ndr_pull_PAC_SIGNATURE_DATA);
+       if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+               status = ndr_map_error2ntstatus(ndr_err);
+               DEBUG(0,("can't parse the KDC signature: %s\n",
+                       nt_errstr(status)));
+               return status;
+       }
+       
+       ndr_err = ndr_pull_struct_blob(srv_sig_blob, srv_sig_wipe, 
+                                      iconv_convenience, srv_sig_wipe,
+                                      (ndr_pull_flags_fn_t)ndr_pull_PAC_SIGNATURE_DATA);
+       if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+               status = ndr_map_error2ntstatus(ndr_err);
+               DEBUG(0,("can't parse the SRV signature: %s\n",
+                       nt_errstr(status)));
                return status;
        }
-       NDR_PRINT_DEBUG(PAC_DATA, &pac_data);
 
-       /* verify by servie_key */
-       status = kerberos_pac_checksum(mem_ctx, 
-                                      modified_pac_blob, &srv_sig, 
-                                      smb_krb5_context, keyblock, 0);
+       /* Now zero the decoded structure */
+       memset(kdc_sig_wipe->signature.data, '\0', kdc_sig_wipe->signature.length);
+       memset(srv_sig_wipe->signature.data, '\0', srv_sig_wipe->signature.length);
+       
+       /* and reencode, back into the same place it came from */
+       ndr_err = ndr_push_struct_blob(kdc_sig_blob, pac_data_raw, 
+                                      iconv_convenience,
+                                      kdc_sig_wipe,
+                                      (ndr_push_flags_fn_t)ndr_push_PAC_SIGNATURE_DATA);
+       if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+               status = ndr_map_error2ntstatus(ndr_err);
+               DEBUG(0,("can't repack the KDC signature: %s\n",
+                       nt_errstr(status)));
+               return status;
+       }
+       ndr_err = ndr_push_struct_blob(srv_sig_blob, pac_data_raw, 
+                                      iconv_convenience,
+                                      srv_sig_wipe,
+                                      (ndr_push_flags_fn_t)ndr_push_PAC_SIGNATURE_DATA);
+       if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+               status = ndr_map_error2ntstatus(ndr_err);
+               DEBUG(0,("can't repack the SRV signature: %s\n",
+                       nt_errstr(status)));
+               return status;
+       }
 
-       if (!NT_STATUS_IS_OK(status)) {
+       /* push out the whole structure, but now with zero'ed signatures */
+       ndr_err = ndr_push_struct_blob(&modified_pac_blob, pac_data_raw, 
+                                      iconv_convenience,
+                                      pac_data_raw,
+                                      (ndr_push_flags_fn_t)ndr_push_PAC_DATA_RAW);
+       if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+               status = ndr_map_error2ntstatus(ndr_err);
+               DEBUG(0,("can't repack the RAW PAC: %s\n",
+                       nt_errstr(status)));
                return status;
        }
-       DEBUG(0,("account_name: %s [%s]\n",
+
+       /* verify by service_key */
+       ret = check_pac_checksum(mem_ctx, 
+                                modified_pac_blob, srv_sig_ptr, 
+                                context, 
+                                service_keyblock);
+       if (ret) {
+               DEBUG(1, ("PAC Decode: Failed to verify the service signature: %s\n",
+                         smb_get_krb5_error_message(context, ret, mem_ctx)));
+               if (k5ret) {
+                       *k5ret = ret;
+               }
+               return NT_STATUS_ACCESS_DENIED;
+       }
+
+       if (krbtgt_keyblock) {
+               ret = check_pac_checksum(mem_ctx, 
+                                           srv_sig_ptr->signature, kdc_sig_ptr, 
+                                           context, krbtgt_keyblock);
+               if (ret) {
+                       DEBUG(1, ("PAC Decode: Failed to verify the KDC signature: %s\n",
+                                 smb_get_krb5_error_message(context, ret, mem_ctx)));
+                       if (k5ret) {
+                               *k5ret = ret;
+                       }
+                       return NT_STATUS_ACCESS_DENIED;
+               }
+       }
+
+       /* Convert to NT time, so as not to loose accuracy in comparison */
+       unix_to_nt_time(&tgs_authtime_nttime, tgs_authtime);
+
+       if (tgs_authtime_nttime != logon_name->logon_time) {
+               DEBUG(2, ("PAC Decode: Logon time mismatch between ticket and PAC!\n"));
+               DEBUG(2, ("PAC Decode: PAC: %s\n", nt_time_string(mem_ctx, logon_name->logon_time)));
+               DEBUG(2, ("PAC Decode: Ticket: %s\n", nt_time_string(mem_ctx, tgs_authtime_nttime)));
+               return NT_STATUS_ACCESS_DENIED;
+       }
+
+       ret = krb5_parse_name_flags(context, logon_name->account_name, KRB5_PRINCIPAL_PARSE_NO_REALM, 
+                                   &client_principal_pac);
+       if (ret) {
+               DEBUG(2, ("Could not parse name from incoming PAC: [%s]: %s\n", 
+                         logon_name->account_name, 
+                         smb_get_krb5_error_message(context, ret, mem_ctx)));
+               if (k5ret) {
+                       *k5ret = ret;
+               }
+               return NT_STATUS_INVALID_PARAMETER;
+       }
+
+       if (!krb5_principal_compare_any_realm(context, client_principal, client_principal_pac)) {
+               DEBUG(2, ("Name in PAC [%s] does not match principal name in ticket\n", 
+                         logon_name->account_name));
+               return NT_STATUS_ACCESS_DENIED;
+       }
+       
+#if 0
+       if (strcasecmp(logon_info->info3.base.account_name.string, 
+                      "Administrator")== 0) {
+               file_save("tmp_pac_data-admin.dat",blob.data,blob.length);
+       }
+#endif
+
+       DEBUG(3,("Found account name from PAC: %s [%s]\n",
                 logon_info->info3.base.account_name.string, 
                 logon_info->info3.base.full_name.string));
-       *logon_info_out = logon_info;
+       *pac_data_out = pac_data;
+
+       return NT_STATUS_OK;
+}
+
+_PUBLIC_  NTSTATUS kerberos_pac_logon_info(TALLOC_CTX *mem_ctx,
+                                 struct smb_iconv_convenience *iconv_convenience,
+                                 struct PAC_LOGON_INFO **logon_info,
+                                 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, 
+                                 krb5_error_code *k5ret)
+{
+       NTSTATUS nt_status;
+       struct PAC_DATA *pac_data;
+       int i;
+       nt_status = kerberos_decode_pac(mem_ctx, 
+                                       iconv_convenience,
+                                       &pac_data,
+                                       blob,
+                                       context,
+                                       krbtgt_keyblock,
+                                       service_keyblock,
+                                       client_principal, 
+                                       tgs_authtime,
+                                       k5ret);
+       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 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;
+
+
+       ret = krb5_crypto_init(context,
+                              keyblock,
+                              0,
+                              &crypto);
+       if (ret) {
+               DEBUG(0,("krb5_crypto_init() failed: %s\n",
+                         smb_get_krb5_error_message(context, ret, mem_ctx)));
+               return ret;
+       }
+       ret = krb5_create_checksum(context,
+                                  crypto,
+                                  KRB5_KU_OTHER_CKSUM,
+                                  0,
+                                  pac_data->data,
+                                  pac_data->length,
+                                  &cksum);
+       if (ret) {
+               DEBUG(2, ("PAC Verification failed: %s\n", 
+                         smb_get_krb5_error_message(context, ret, mem_ctx)));
+       }
+
+       krb5_crypto_destroy(context, crypto);
+
+       if (ret) {
+               return ret;
+       }
+
+       sig->type = cksum.cksumtype;
+       sig->signature = data_blob_talloc(mem_ctx, cksum.checksum.data, cksum.checksum.length);
+       free_Checksum(&cksum);
+
+       return 0;
+}
+
+ krb5_error_code kerberos_encode_pac(TALLOC_CTX *mem_ctx,
+                                    struct smb_iconv_convenience *iconv_convenience,
+                                   struct PAC_DATA *pac_data,
+                                   krb5_context context,
+                                   const krb5_keyblock *krbtgt_keyblock,
+                                   const krb5_keyblock *service_keyblock,
+                                   DATA_BLOB *pac) 
+{
+       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;
+
+       /* 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;
+               }
+       }
+       
+       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_checksum) {
+               DEBUG(2, ("Invalid PAC constructed for signing, no KDC checksum present!"));
+               return EINVAL;
+       }
+       if (!srv_checksum) {
+               DEBUG(2, ("Invalid PAC constructed for signing, no SRV checksum present!"));
+               return EINVAL;
+       }
+
+       /* 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, 
+                                      iconv_convenience,
+                                      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;
+       }
+
+       /* 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);
+
+       /* Then sign Server checksum */
+       ret = make_pac_checksum(mem_ctx, &srv_checksum->signature, 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;
+       }
+
+       /* 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, 
+                                      iconv_convenience,
+                                      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;
+       }
+
+       *pac = tmp_blob;
+
+       return ret;
+}
+
+
+ krb5_error_code kerberos_create_pac(TALLOC_CTX *mem_ctx,
+                                    struct smb_iconv_convenience *iconv_convenience,
+                                    struct auth_serversupplied_info *server_info,
+                                    krb5_context context,
+                                    const krb5_keyblock *krbtgt_keyblock,
+                                    const krb5_keyblock *service_keyblock,
+                                    krb5_principal client_principal,
+                                    time_t tgs_authtime,
+                                    DATA_BLOB *pac)
+{
+       NTSTATUS nt_status;
+       krb5_error_code ret;
+       struct PAC_DATA *pac_data = talloc(mem_ctx, struct PAC_DATA);
+       struct netr_SamInfo3 *sam3;
+       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;
+       union PAC_INFO *u_SRV_CHECKSUM;
+
+       char *name;
+               
+       enum {
+               PAC_BUF_LOGON_INFO = 0,
+               PAC_BUF_LOGON_NAME = 1,
+               PAC_BUF_SRV_CHECKSUM = 2,
+               PAC_BUF_KDC_CHECKSUM = 3,
+               PAC_BUF_NUM_BUFFERS = 4
+       };
+
+       if (!pac_data) {
+               return ENOMEM;
+       }
+
+       pac_data->num_buffers = PAC_BUF_NUM_BUFFERS;
+       pac_data->version = 0;
+
+       pac_data->buffers = talloc_array(pac_data, 
+                                        struct PAC_BUFFER,
+                                        pac_data->num_buffers);
+       if (!pac_data->buffers) {
+               talloc_free(pac_data);
+               return ENOMEM;
+       }
+
+       /* LOGON_INFO */
+       u_LOGON_INFO = talloc_zero(pac_data->buffers, union PAC_INFO);
+       if (!u_LOGON_INFO) {
+               talloc_free(pac_data);
+               return ENOMEM;
+       }
+       pac_data->buffers[PAC_BUF_LOGON_INFO].type = PAC_TYPE_LOGON_INFO;
+       pac_data->buffers[PAC_BUF_LOGON_INFO].info = u_LOGON_INFO;
+
+       /* LOGON_NAME */
+       u_LOGON_NAME = talloc_zero(pac_data->buffers, union PAC_INFO);
+       if (!u_LOGON_NAME) {
+               talloc_free(pac_data);
+               return ENOMEM;
+       }
+       pac_data->buffers[PAC_BUF_LOGON_NAME].type = PAC_TYPE_LOGON_NAME;
+       pac_data->buffers[PAC_BUF_LOGON_NAME].info = u_LOGON_NAME;
+       LOGON_NAME = &u_LOGON_NAME->logon_name;
+
+       /* SRV_CHECKSUM */
+       u_SRV_CHECKSUM = talloc_zero(pac_data->buffers, union PAC_INFO);
+       if (!u_SRV_CHECKSUM) {
+               talloc_free(pac_data);
+               return ENOMEM;
+       }
+       pac_data->buffers[PAC_BUF_SRV_CHECKSUM].type = PAC_TYPE_SRV_CHECKSUM;
+       pac_data->buffers[PAC_BUF_SRV_CHECKSUM].info = u_SRV_CHECKSUM;
+
+       /* KDC_CHECKSUM */
+       u_KDC_CHECKSUM = talloc_zero(pac_data->buffers, union PAC_INFO);
+       if (!u_KDC_CHECKSUM) {
+               talloc_free(pac_data);
+               return ENOMEM;
+       }
+       pac_data->buffers[PAC_BUF_KDC_CHECKSUM].type = PAC_TYPE_KDC_CHECKSUM;
+       pac_data->buffers[PAC_BUF_KDC_CHECKSUM].info = u_KDC_CHECKSUM;
+
+       /* now the real work begins... */
+
+       LOGON_INFO = talloc_zero(u_LOGON_INFO, struct PAC_LOGON_INFO);
+       if (!LOGON_INFO) {
+               talloc_free(pac_data);
+               return ENOMEM;
+       }
+       nt_status = auth_convert_server_info_saminfo3(LOGON_INFO, server_info, &sam3);
+       if (!NT_STATUS_IS_OK(nt_status)) {
+               DEBUG(1, ("Getting Samba info failed: %s\n", nt_errstr(nt_status)));
+               talloc_free(pac_data);
+               return EINVAL;
+       }
+
+       u_LOGON_INFO->logon_info.info           = LOGON_INFO;
+       LOGON_INFO->info3 = *sam3;
+
+       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, 
+                                 iconv_convenience,
+                                 pac_data, 
+                                 context,
+                                 krbtgt_keyblock,
+                                 service_keyblock,
+                                 pac);
+       talloc_free(pac_data);
+       return ret;
+}
+
+krb5_error_code kerberos_pac_to_server_info(TALLOC_CTX *mem_ctx,
+                                               struct smb_iconv_convenience *iconv_convenience,
+                                               krb5_pac pac,
+                                               krb5_context context,
+                                               struct auth_serversupplied_info **server_info) 
+{
+       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;
+
+       union PAC_INFO info;
+       union netr_Validation validation;
+       struct auth_serversupplied_info *server_info_out;
+
+       TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
+
+       if (!tmp_ctx) {
+               return ENOMEM;
+       }
+
+       ret = krb5_pac_get_buffer(context, pac, PAC_TYPE_LOGON_INFO, &k5pac_logon_info_in);
+       if (ret != 0) {
+               talloc_free(tmp_ctx);
+               return EINVAL;
+       }
+
+       pac_logon_info_in = data_blob_const(k5pac_logon_info_in.data, k5pac_logon_info_in.length);
 
-       return status;
+       ndr_err = ndr_pull_union_blob(&pac_logon_info_in, tmp_ctx, iconv_convenience, &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;
+       }
+
+       /* Pull this right into the normal auth sysstem structures */
+       validation.sam3 = &info.logon_info.info->info3;
+       nt_status = make_server_info_netlogon_validation(mem_ctx,
+                                                        "",
+                                                        3, &validation,
+                                                        &server_info_out); 
+       if (!NT_STATUS_IS_OK(nt_status)) {
+               talloc_free(tmp_ctx);
+               return EINVAL;
+       }
+       
+       ret = krb5_pac_get_buffer(context, pac, PAC_TYPE_SRV_CHECKSUM, &k5pac_srv_checksum_in);
+       if (ret != 0) {
+               talloc_free(tmp_ctx);
+               return ret;
+       }
+
+       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, server_info_out, 
+                                      iconv_convenience, &server_info_out->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;
+       }
+
+       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, server_info_out, 
+                                      iconv_convenience, &server_info_out->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;
+       }
+
+       *server_info = server_info_out;
+       
+       return 0;
 }
 
+
+NTSTATUS kerberos_pac_blob_to_server_info(TALLOC_CTX *mem_ctx,
+                                                    struct smb_iconv_convenience *iconv_convenience,
+                                                    DATA_BLOB pac_blob, 
+                                                    krb5_context context,
+                                                    struct auth_serversupplied_info **server_info) 
+{
+       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(ret);
+       }
+
+
+       ret = kerberos_pac_to_server_info(mem_ctx, iconv_convenience, pac, context, server_info);
+       krb5_pac_free(context, pac);
+       if (ret) {
+               return map_nt_error_from_unix(ret);
+       }
+       return NT_STATUS_OK;
+}