diff options
Diffstat (limited to 'source4/auth/kerberos/kerberos_pac.c')
| -rw-r--r-- | source4/auth/kerberos/kerberos_pac.c | 496 |
1 files changed, 496 insertions, 0 deletions
diff --git a/source4/auth/kerberos/kerberos_pac.c b/source4/auth/kerberos/kerberos_pac.c new file mode 100644 index 0000000..156a140 --- /dev/null +++ b/source4/auth/kerberos/kerberos_pac.c @@ -0,0 +1,496 @@ +/* + Unix SMB/CIFS implementation. + + Create and parse the krb5 PAC + + 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 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 "system/kerberos.h" +#include "auth/auth.h" +#include "auth/kerberos/kerberos.h" +#include "librpc/gen_ndr/ndr_krb5pac.h" +#include <ldb.h> +#include "auth/auth_sam_reply.h" +#include "auth/credentials/credentials.h" +#include "auth/kerberos/kerberos_util.h" +#include "auth/kerberos/pac_utils.h" + + 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 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; + uint32_t 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 = smb_krb5_make_pac_checksum(mem_ctx, + &zero_blob, + context, + krbtgt_keyblock, + &kdc_checksum->type, + &kdc_checksum->signature); + 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 = smb_krb5_make_pac_checksum(mem_ctx, + &zero_blob, + context, + service_keyblock, + &srv_checksum->type, + &srv_checksum->signature); + 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, + 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 = smb_krb5_make_pac_checksum(mem_ctx, + &tmp_blob, + context, + service_keyblock, + &srv_checksum->type, + &srv_checksum->signature); + + if (ret) { + DBG_WARNING("making krbtgt PAC srv_checksum failed: %s\n", + smb_get_krb5_error_message(context, ret, mem_ctx)); + talloc_free(pac_data); + return ret; + } + + /* Then sign Server checksum */ + ret = smb_krb5_make_pac_checksum(mem_ctx, + &srv_checksum->signature, + context, + krbtgt_keyblock, + &kdc_checksum->type, + &kdc_checksum->signature); + if (ret) { + DBG_WARNING("making krbtgt PAC kdc_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, + 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 auth_user_info_dc *user_info_dc, + 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_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); + 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 | + KRB5_PRINCIPAL_UNPARSE_DISPLAY, + &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; +} + +static krb5_error_code kerberos_pac_buffer_present(krb5_context context, + const krb5_pac pac, + uint32_t type) +{ +#ifdef SAMBA4_USES_HEIMDAL + return krb5_pac_get_buffer(context, pac, type, NULL); +#else /* MIT */ + krb5_error_code ret; + krb5_data data; + + /* + * MIT won't let us pass NULL for the data parameter, so we are forced + * to allocate a new buffer and then immediately free it. + */ + ret = krb5_pac_get_buffer(context, pac, type, &data); + if (ret == 0) { + krb5_free_data_contents(context, &data); + } + return ret; +#endif /* SAMBA4_USES_HEIMDAL */ +} + +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; + DATA_BLOB pac_upn_dns_info_in; + krb5_data k5pac_upn_dns_info_in; + + union PAC_INFO info; + union PAC_INFO _upn_dns_info; + struct PAC_UPN_DNS_INFO *upn_dns_info = NULL; + struct auth_user_info_dc *user_info_dc_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); + + 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); + smb_krb5_free_data_contents(context, &k5pac_logon_info_in); + if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) { + 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; + } + if (info.logon_info.info == NULL) { + DEBUG(0,("can't parse the PAC LOGON_INFO: missing info pointer\n")); + talloc_free(tmp_ctx); + return EINVAL; + } + + ret = krb5_pac_get_buffer(context, pac, PAC_TYPE_UPN_DNS_INFO, + &k5pac_upn_dns_info_in); + if (ret == ENOENT) { + ZERO_STRUCT(k5pac_upn_dns_info_in); + ret = 0; + } + if (ret != 0) { + talloc_free(tmp_ctx); + return EINVAL; + } + + pac_upn_dns_info_in = data_blob_const(k5pac_upn_dns_info_in.data, + k5pac_upn_dns_info_in.length); + + if (pac_upn_dns_info_in.length != 0) { + ndr_err = ndr_pull_union_blob(&pac_upn_dns_info_in, tmp_ctx, + &_upn_dns_info, + PAC_TYPE_UPN_DNS_INFO, + (ndr_pull_flags_fn_t)ndr_pull_PAC_INFO); + smb_krb5_free_data_contents(context, &k5pac_upn_dns_info_in); + if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) { + nt_status = ndr_map_error2ntstatus(ndr_err); + DEBUG(0,("can't parse the PAC UPN_DNS_INFO: %s\n", + nt_errstr(nt_status))); + talloc_free(tmp_ctx); + return EINVAL; + } + upn_dns_info = &_upn_dns_info.upn_dns_info; + } + + /* Pull this right into the normal auth sysstem structures */ + nt_status = make_user_info_dc_pac(mem_ctx, + info.logon_info.info, + upn_dns_info, + &user_info_dc_out); + if (!NT_STATUS_IS_OK(nt_status)) { + DBG_ERR("make_user_info_dc_pac() failed -%s\n", + nt_errstr(nt_status)); + NDR_PRINT_DEBUG(PAC_LOGON_INFO, info.logon_info.info); + if (upn_dns_info != NULL) { + NDR_PRINT_DEBUG(PAC_UPN_DNS_INFO, upn_dns_info); + } + talloc_free(tmp_ctx); + return EINVAL; + } + + 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; + } + + 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); + smb_krb5_free_data_contents(context, &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; + } + } + + 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); + smb_krb5_free_data_contents(context, &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; + } + } + + /* + * Based on the presence of a REQUESTER_SID PAC buffer, ascertain + * whether the ticket is a TGT. This helps the KDC and kpasswd service + * ensure they do not accept tickets meant for the other. + * + * This heuristic will fail for older Samba versions and Windows prior + * to Nov. 2021 updates, which lack support for the REQUESTER_SID PAC + * buffer. + */ + ret = kerberos_pac_buffer_present(context, pac, PAC_TYPE_REQUESTER_SID); + if (ret == ENOENT) { + /* This probably isn't a TGT. */ + user_info_dc_out->ticket_type = TICKET_TYPE_NON_TGT; + } else if (ret != 0) { + talloc_free(tmp_ctx); + return ret; + } else { + /* This probably is a TGT. */ + user_info_dc_out->ticket_type = TICKET_TYPE_TGT; + } + + *user_info_dc = user_info_dc_out; + + 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); + } + + + 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; +} |