/* Unix SMB/CIFS implementation. kerberos authorization data (PAC) utility library Copyright (C) Jim McDonough <jmcd@us.ibm.com> 2003 Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004-2005 Copyright (C) Andrew Tridgell 2001 Copyright (C) Luke Howard 2002-2003 Copyright (C) Stefan Metzmacher 2004-2005 Copyright (C) Guenther Deschner 2005,2007,2008 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 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, see <http://www.gnu.org/licenses/>. */ #include "includes.h" #include "librpc/gen_ndr/ndr_krb5pac.h" #ifdef HAVE_KRB5 /**************************************************************** ****************************************************************/ static krb5_error_code check_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_checksum cksum; krb5_keyusage usage = 0; smb_krb5_checksum_from_pac_sig(&cksum, sig); #ifdef HAVE_KRB5_KU_OTHER_CKSUM /* Heimdal */ usage = KRB5_KU_OTHER_CKSUM; #elif defined(HAVE_KRB5_KEYUSAGE_APP_DATA_CKSUM) /* MIT */ usage = KRB5_KEYUSAGE_APP_DATA_CKSUM; #else #error UNKNOWN_KRB5_KEYUSAGE #endif ret = smb_krb5_verify_checksum(context, keyblock, usage, &cksum, pac_data.data, pac_data.length); if (ret) { DEBUG(2,("check_pac_checksum: PAC Verification failed: %s (%d)\n", error_message(ret), ret)); return ret; } return ret; } /**************************************************************** ****************************************************************/ NTSTATUS decode_pac_data(TALLOC_CTX *mem_ctx, DATA_BLOB *pac_data_blob, krb5_context context, krb5_keyblock *service_keyblock, krb5_const_principal client_principal, time_t tgs_authtime, struct PAC_DATA **pac_data_out) { NTSTATUS status; enum ndr_err_code ndr_err; krb5_error_code ret; DATA_BLOB modified_pac_blob; NTTIME tgs_authtime_nttime; krb5_principal client_principal_pac = NULL; int i; struct PAC_SIGNATURE_DATA *srv_sig_ptr = NULL; 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_NAME *logon_name = NULL; struct PAC_LOGON_INFO *logon_info = NULL; struct PAC_DATA *pac_data = NULL; struct PAC_DATA_RAW *pac_data_raw = NULL; DATA_BLOB *srv_sig_blob = NULL; DATA_BLOB *kdc_sig_blob = NULL; *pac_data_out = NULL; pac_data = TALLOC_ZERO_P(mem_ctx, struct PAC_DATA); pac_data_raw = TALLOC_ZERO_P(mem_ctx, struct PAC_DATA_RAW); kdc_sig_wipe = TALLOC_ZERO_P(mem_ctx, struct PAC_SIGNATURE_DATA); srv_sig_wipe = TALLOC_ZERO_P(mem_ctx, struct PAC_SIGNATURE_DATA); if (!pac_data_raw || !pac_data || !kdc_sig_wipe || !srv_sig_wipe) { return NT_STATUS_NO_MEMORY; } ndr_err = ndr_pull_struct_blob(pac_data_blob, pac_data, NULL, 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(pac_data_blob, pac_data_raw, NULL, 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; } 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,("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++) { 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) { 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_blob = &pac_data_raw->buffers[i].info->remaining; 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_blob = &pac_data_raw->buffers[i].info->remaining; break; case PAC_TYPE_LOGON_NAME: logon_name = &pac_data->buffers[i].info->logon_name; break; default: break; } } if (!logon_info) { DEBUG(0,("PAC no logon_info\n")); return NT_STATUS_INVALID_PARAMETER; } if (!logon_name) { DEBUG(0,("PAC no logon_name\n")); return NT_STATUS_INVALID_PARAMETER; } if (!srv_sig_ptr || !srv_sig_blob) { DEBUG(0,("PAC no srv_key\n")); return NT_STATUS_INVALID_PARAMETER; } if (!kdc_sig_ptr || !kdc_sig_blob) { DEBUG(0,("PAC no kdc_key\n")); return NT_STATUS_INVALID_PARAMETER; } /* Find and zero out the signatures, as required by the signing algorithm */ /* 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, NULL, 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, NULL, 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; } /* 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, NULL, 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, NULL, 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; } /* push out the whole structure, but now with zero'ed signatures */ ndr_err = ndr_push_struct_blob(&modified_pac_blob, pac_data_raw, NULL, 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; } /* 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", error_message(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 = smb_krb5_parse_name_norealm(context, logon_name->account_name, &client_principal_pac); if (ret) { DEBUG(2, ("Could not parse name from incoming PAC: [%s]: %s\n", logon_name->account_name, error_message(ret))); return NT_STATUS_INVALID_PARAMETER; } if (!smb_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)); krb5_free_principal(context, client_principal_pac); return NT_STATUS_ACCESS_DENIED; } DEBUG(3,("Found account name from PAC: %s [%s]\n", logon_info->info3.base.account_name.string, logon_info->info3.base.full_name.string)); DEBUG(10,("Successfully validated Kerberos PAC\n")); if (DEBUGLEVEL >= 10) { const char *s; s = NDR_PRINT_STRUCT_STRING(mem_ctx, PAC_DATA, pac_data); if (s) { DEBUGADD(10,("%s\n", s)); } } *pac_data_out = pac_data; return NT_STATUS_OK; } /**************************************************************** ****************************************************************/ struct PAC_LOGON_INFO *get_logon_info_from_pac(struct PAC_DATA *pac_data) { int i; for (i=0; i < pac_data->num_buffers; i++) { if (pac_data->buffers[i].type != PAC_TYPE_LOGON_INFO) { continue; } return pac_data->buffers[i].info->logon_info.info; } return NULL; } /**************************************************************** ****************************************************************/ NTSTATUS kerberos_return_pac(TALLOC_CTX *mem_ctx, const char *name, const char *pass, time_t time_offset, time_t *expire_time, time_t *renew_till_time, const char *cache_name, bool request_pac, bool add_netbios_addr, time_t renewable_time, struct PAC_DATA **pac_ret) { krb5_error_code ret; NTSTATUS status = NT_STATUS_INVALID_PARAMETER; DATA_BLOB tkt, ap_rep, sesskey1, sesskey2; struct PAC_DATA *pac_data = NULL; char *client_princ_out = NULL; const char *auth_princ = NULL; const char *local_service = NULL; const char *cc = "MEMORY:kerberos_return_pac"; ZERO_STRUCT(tkt); ZERO_STRUCT(ap_rep); ZERO_STRUCT(sesskey1); ZERO_STRUCT(sesskey2); if (!name || !pass) { return NT_STATUS_INVALID_PARAMETER; } if (cache_name) { cc = cache_name; } if (!strchr_m(name, '@')) { auth_princ = talloc_asprintf(mem_ctx, "%s@%s", name, lp_realm()); } else { auth_princ = name; } NT_STATUS_HAVE_NO_MEMORY(auth_princ); local_service = talloc_asprintf(mem_ctx, "%s$@%s", global_myname(), lp_realm()); NT_STATUS_HAVE_NO_MEMORY(local_service); ret = kerberos_kinit_password_ext(auth_princ, pass, time_offset, expire_time, renew_till_time, cc, request_pac, add_netbios_addr, renewable_time, &status); if (ret) { DEBUG(1,("kinit failed for '%s' with: %s (%d)\n", auth_princ, error_message(ret), ret)); /* status already set */ goto out; } DEBUG(10,("got TGT for %s in %s\n", auth_princ, cc)); if (expire_time) { DEBUGADD(10,("\tvalid until: %s (%d)\n", http_timestring(talloc_tos(), *expire_time), (int)*expire_time)); } if (renew_till_time) { DEBUGADD(10,("\trenewable till: %s (%d)\n", http_timestring(talloc_tos(), *renew_till_time), (int)*renew_till_time)); } /* we cannot continue with krb5 when UF_DONT_REQUIRE_PREAUTH is set, * in that case fallback to NTLM - gd */ if (expire_time && renew_till_time && (*expire_time == 0) && (*renew_till_time == 0)) { return NT_STATUS_INVALID_LOGON_TYPE; } ret = cli_krb5_get_ticket(local_service, time_offset, &tkt, &sesskey1, 0, cc, NULL); if (ret) { DEBUG(1,("failed to get ticket for %s: %s\n", local_service, error_message(ret))); status = krb5_to_nt_status(ret); goto out; } status = ads_verify_ticket(mem_ctx, lp_realm(), time_offset, &tkt, &client_princ_out, &pac_data, &ap_rep, &sesskey2, False); if (!NT_STATUS_IS_OK(status)) { DEBUG(1,("ads_verify_ticket failed: %s\n", nt_errstr(status))); goto out; } if (!pac_data) { DEBUG(1,("no PAC\n")); status = NT_STATUS_INVALID_PARAMETER; goto out; } *pac_ret = pac_data; out: if (cc != cache_name) { ads_kdestroy(cc); } data_blob_free(&tkt); data_blob_free(&ap_rep); data_blob_free(&sesskey1); data_blob_free(&sesskey2); TALLOC_FREE(client_princ_out); return status; } /**************************************************************** ****************************************************************/ static NTSTATUS kerberos_return_pac_logon_info(TALLOC_CTX *mem_ctx, const char *name, const char *pass, time_t time_offset, time_t *expire_time, time_t *renew_till_time, const char *cache_name, bool request_pac, bool add_netbios_addr, time_t renewable_time, struct PAC_LOGON_INFO **logon_info) { NTSTATUS status; struct PAC_DATA *pac_data = NULL; struct PAC_LOGON_INFO *info = NULL; status = kerberos_return_pac(mem_ctx, name, pass, time_offset, expire_time, renew_till_time, cache_name, request_pac, add_netbios_addr, renewable_time, &pac_data); if (!NT_STATUS_IS_OK(status)) { return status; } if (!pac_data) { DEBUG(3,("no pac\n")); return NT_STATUS_INVALID_USER_BUFFER; } info = get_logon_info_from_pac(pac_data); if (!info) { DEBUG(1,("no logon_info\n")); return NT_STATUS_INVALID_USER_BUFFER; } *logon_info = info; return NT_STATUS_OK; } /**************************************************************** ****************************************************************/ NTSTATUS kerberos_return_info3_from_pac(TALLOC_CTX *mem_ctx, const char *name, const char *pass, time_t time_offset, time_t *expire_time, time_t *renew_till_time, const char *cache_name, bool request_pac, bool add_netbios_addr, time_t renewable_time, struct netr_SamInfo3 **info3) { NTSTATUS status; struct PAC_LOGON_INFO *logon_info = NULL; status = kerberos_return_pac_logon_info(mem_ctx, name, pass, time_offset, expire_time, renew_till_time, cache_name, request_pac, add_netbios_addr, renewable_time, &logon_info); if (!NT_STATUS_IS_OK(status)) { return status; } *info3 = &logon_info->info3; return NT_STATUS_OK; } #endif