Copyright (C) Andrew Tridgell 2001
Copyright (C) Remus Koos 2001
Copyright (C) Luke Howard 2003
+ Copyright (C) Guenther Deschner 2003, 2005
+ Copyright (C) Jim McDonough (jmcd@us.ibm.com) 2003
+ Copyright (C) Andrew Bartlett <abartlet@samba.org> 2004-2005
+ Copyright (C) Jeremy Allison 2007
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
#ifdef HAVE_KRB5
-/*
- verify an incoming ticket and parse out the principal name and
- authorization_data if available
-*/
-NTSTATUS ads_verify_ticket(ADS_STRUCT *ads, const DATA_BLOB *ticket,
- char **principal, DATA_BLOB *auth_data,
- DATA_BLOB *ap_rep,
- uint8 session_key[16])
+#if !defined(HAVE_KRB5_PRINC_COMPONENT)
+const krb5_data *krb5_princ_component(krb5_context, krb5_principal, int );
+#endif
+
+/**********************************************************************************
+ Try to verify a ticket using the system keytab... the system keytab has kvno -1 entries, so
+ it's more like what microsoft does... see comment in utils/net_ads.c in the
+ ads_keytab_add_entry function for details.
+***********************************************************************************/
+
+static BOOL ads_keytab_verify_ticket(krb5_context context,
+ krb5_auth_context auth_context,
+ const DATA_BLOB *ticket,
+ krb5_ticket **pp_tkt,
+ krb5_keyblock **keyblock,
+ krb5_error_code *perr)
{
- NTSTATUS sret = NT_STATUS_LOGON_FAILURE;
- krb5_context context = NULL;
- krb5_auth_context auth_context = NULL;
+ krb5_error_code ret = 0;
+ BOOL auth_ok = False;
krb5_keytab keytab = NULL;
+ krb5_kt_cursor kt_cursor;
+ krb5_keytab_entry kt_entry;
+ char *valid_princ_formats[7] = { NULL, NULL, NULL, NULL, NULL, NULL, NULL };
+ char *entry_princ_s = NULL;
+ fstring my_name, my_fqdn;
+ int i;
+ int number_matched_principals = 0;
krb5_data packet;
- krb5_ticket *tkt = NULL;
- krb5_rcache rcache = NULL;
- int ret, i;
- krb5_keyblock *key = NULL;
- krb5_principal host_princ;
- char *host_princ_s = NULL;
- fstring myname;
+
+ *pp_tkt = NULL;
+ *keyblock = NULL;
+ *perr = 0;
+
+ /* Generate the list of principal names which we expect
+ * clients might want to use for authenticating to the file
+ * service. We allow name$,{host,cifs}/{name,fqdn,name.REALM}. */
+
+ fstrcpy(my_name, global_myname());
+
+ my_fqdn[0] = '\0';
+ name_to_fqdn(my_fqdn, global_myname());
+
+ asprintf(&valid_princ_formats[0], "%s$@%s", my_name, lp_realm());
+ asprintf(&valid_princ_formats[1], "host/%s@%s", my_name, lp_realm());
+ asprintf(&valid_princ_formats[2], "host/%s@%s", my_fqdn, lp_realm());
+ asprintf(&valid_princ_formats[3], "host/%s.%s@%s", my_name, lp_realm(), lp_realm());
+ asprintf(&valid_princ_formats[4], "cifs/%s@%s", my_name, lp_realm());
+ asprintf(&valid_princ_formats[5], "cifs/%s@%s", my_fqdn, lp_realm());
+ asprintf(&valid_princ_formats[6], "cifs/%s.%s@%s", my_name, lp_realm(), lp_realm());
+
+ ZERO_STRUCT(kt_entry);
+ ZERO_STRUCT(kt_cursor);
+
+ ret = smb_krb5_open_keytab(context, NULL, False, &keytab);
+ if (ret) {
+ DEBUG(1, ("ads_keytab_verify_ticket: smb_krb5_open_keytab failed (%s)\n", error_message(ret)));
+ goto out;
+ }
+
+ /* Iterate through the keytab. For each key, if the principal
+ * name case-insensitively matches one of the allowed formats,
+ * try verifying the ticket using that principal. */
+
+ ret = krb5_kt_start_seq_get(context, keytab, &kt_cursor);
+ if (ret) {
+ DEBUG(1, ("ads_keytab_verify_ticket: krb5_kt_start_seq_get failed (%s)\n", error_message(ret)));
+ goto out;
+ }
+
+ while (!auth_ok && (krb5_kt_next_entry(context, keytab, &kt_entry, &kt_cursor) == 0)) {
+ ret = smb_krb5_unparse_name(context, kt_entry.principal, &entry_princ_s);
+ if (ret) {
+ DEBUG(1, ("ads_keytab_verify_ticket: smb_krb5_unparse_name failed (%s)\n",
+ error_message(ret)));
+ goto out;
+ }
+
+ for (i = 0; i < ARRAY_SIZE(valid_princ_formats); i++) {
+
+ if (!strequal(entry_princ_s, valid_princ_formats[i])) {
+ continue;
+ }
+
+ number_matched_principals++;
+ packet.length = ticket->length;
+ packet.data = (char *)ticket->data;
+ *pp_tkt = NULL;
+
+ ret = krb5_rd_req_return_keyblock_from_keytab(context, &auth_context, &packet,
+ kt_entry.principal, keytab,
+ NULL, pp_tkt, keyblock);
+
+ if (ret) {
+ DEBUG(10,("ads_keytab_verify_ticket: "
+ "krb5_rd_req_return_keyblock_from_keytab(%s) failed: %s\n",
+ entry_princ_s, error_message(ret)));
+
+ /* workaround for MIT:
+ * as krb5_ktfile_get_entry will explicitly
+ * close the krb5_keytab as soon as krb5_rd_req
+ * has sucessfully decrypted the ticket but the
+ * ticket is not valid yet (due to clockskew)
+ * there is no point in querying more keytab
+ * entries - Guenther */
+
+ if (ret == KRB5KRB_AP_ERR_TKT_NYV ||
+ ret == KRB5KRB_AP_ERR_TKT_EXPIRED ||
+ ret == KRB5KRB_AP_ERR_SKEW) {
+ break;
+ }
+ } else {
+ DEBUG(3,("ads_keytab_verify_ticket: "
+ "krb5_rd_req_return_keyblock_from_keytab succeeded for principal %s\n",
+ entry_princ_s));
+ auth_ok = True;
+ break;
+ }
+ }
+
+ /* Free the name we parsed. */
+ SAFE_FREE(entry_princ_s);
+
+ /* Free the entry we just read. */
+ smb_krb5_kt_free_entry(context, &kt_entry);
+ ZERO_STRUCT(kt_entry);
+ }
+ krb5_kt_end_seq_get(context, keytab, &kt_cursor);
+
+ ZERO_STRUCT(kt_cursor);
+
+ out:
+
+ for (i = 0; i < ARRAY_SIZE(valid_princ_formats); i++) {
+ SAFE_FREE(valid_princ_formats[i]);
+ }
+
+ if (!auth_ok) {
+ if (!number_matched_principals) {
+ DEBUG(3, ("ads_keytab_verify_ticket: no keytab principals matched expected file service name.\n"));
+ } else {
+ DEBUG(3, ("ads_keytab_verify_ticket: krb5_rd_req failed for all %d matched keytab principals\n",
+ number_matched_principals));
+ }
+ }
+
+ SAFE_FREE(entry_princ_s);
+
+ {
+ krb5_keytab_entry zero_kt_entry;
+ ZERO_STRUCT(zero_kt_entry);
+ if (memcmp(&zero_kt_entry, &kt_entry, sizeof(krb5_keytab_entry))) {
+ smb_krb5_kt_free_entry(context, &kt_entry);
+ }
+ }
+
+ {
+ krb5_kt_cursor zero_csr;
+ ZERO_STRUCT(zero_csr);
+ if ((memcmp(&kt_cursor, &zero_csr, sizeof(krb5_kt_cursor)) != 0) && keytab) {
+ krb5_kt_end_seq_get(context, keytab, &kt_cursor);
+ }
+ }
+
+ if (keytab) {
+ krb5_kt_close(context, keytab);
+ }
+ *perr = ret;
+ return auth_ok;
+}
+
+/**********************************************************************************
+ Try to verify a ticket using the secrets.tdb.
+***********************************************************************************/
+
+static krb5_error_code ads_secrets_verify_ticket(krb5_context context,
+ krb5_auth_context auth_context,
+ krb5_principal host_princ,
+ const DATA_BLOB *ticket,
+ krb5_ticket **pp_tkt,
+ krb5_keyblock **keyblock,
+ krb5_error_code *perr)
+{
+ krb5_error_code ret = 0;
+ BOOL auth_ok = False;
char *password_s = NULL;
krb5_data password;
- krb5_enctype *enctypes = NULL;
-#if 0
- krb5_address local_addr;
- krb5_address remote_addr;
+ krb5_enctype enctypes[] = {
+#if defined(ENCTYPE_ARCFOUR_HMAC)
+ ENCTYPE_ARCFOUR_HMAC,
#endif
- BOOL auth_ok = False;
+ ENCTYPE_DES_CBC_CRC,
+ ENCTYPE_DES_CBC_MD5,
+ ENCTYPE_NULL
+ };
+ krb5_data packet;
+ int i;
+
+ *pp_tkt = NULL;
+ *keyblock = NULL;
+ *perr = 0;
- ZERO_STRUCT(packet);
- ZERO_STRUCT(password);
- ZERO_STRUCTP(auth_data);
- ZERO_STRUCTP(ap_rep);
if (!secrets_init()) {
- DEBUG(1,("ads_verify_ticket: secrets_init failed\n"));
- return NT_STATUS_LOGON_FAILURE;
+ DEBUG(1,("ads_secrets_verify_ticket: secrets_init failed\n"));
+ *perr = KRB5_CONFIG_CANTOPEN;
+ return False;
}
password_s = secrets_fetch_machine_password(lp_workgroup(), NULL, NULL);
if (!password_s) {
- DEBUG(1,("ads_verify_ticket: failed to fetch machine password\n"));
- return NT_STATUS_LOGON_FAILURE;
+ DEBUG(1,("ads_secrets_verify_ticket: failed to fetch machine password\n"));
+ *perr = KRB5_LIBOS_CANTREADPWD;
+ return False;
}
password.data = password_s;
password.length = strlen(password_s);
+ /* CIFS doesn't use addresses in tickets. This would break NAT. JRA */
+
+ packet.length = ticket->length;
+ packet.data = (char *)ticket->data;
+
+ /* We need to setup a auth context with each possible encoding type in turn. */
+ for (i=0;enctypes[i];i++) {
+ krb5_keyblock *key = NULL;
+
+ if (!(key = SMB_MALLOC_P(krb5_keyblock))) {
+ ret = ENOMEM;
+ goto out;
+ }
+
+ if (create_kerberos_key_from_string(context, host_princ, &password, key, enctypes[i])) {
+ SAFE_FREE(key);
+ continue;
+ }
+
+ krb5_auth_con_setuseruserkey(context, auth_context, key);
+
+ if (!(ret = krb5_rd_req(context, &auth_context, &packet,
+ NULL,
+ NULL, NULL, pp_tkt))) {
+ DEBUG(10,("ads_secrets_verify_ticket: enc type [%u] decrypted message !\n",
+ (unsigned int)enctypes[i] ));
+ auth_ok = True;
+ krb5_copy_keyblock(context, key, keyblock);
+ krb5_free_keyblock(context, key);
+ break;
+ }
+
+ DEBUG((ret != KRB5_BAD_ENCTYPE) ? 3 : 10,
+ ("ads_secrets_verify_ticket: enc type [%u] failed to decrypt with error %s\n",
+ (unsigned int)enctypes[i], error_message(ret)));
+
+ /* successfully decrypted but ticket is just not valid at the moment */
+ if (ret == KRB5KRB_AP_ERR_TKT_NYV ||
+ ret == KRB5KRB_AP_ERR_TKT_EXPIRED ||
+ ret == KRB5KRB_AP_ERR_SKEW) {
+ break;
+ }
+
+ krb5_free_keyblock(context, key);
+
+ }
+
+ out:
+ SAFE_FREE(password_s);
+ *perr = ret;
+ return auth_ok;
+}
+
+/**********************************************************************************
+ Verify an incoming ticket and parse out the principal name and
+ authorization_data if available.
+***********************************************************************************/
+
+NTSTATUS ads_verify_ticket(TALLOC_CTX *mem_ctx,
+ const char *realm,
+ time_t time_offset,
+ const DATA_BLOB *ticket,
+ char **principal,
+ PAC_DATA **pac_data,
+ DATA_BLOB *ap_rep,
+ DATA_BLOB *session_key,
+ BOOL use_replay_cache)
+{
+ NTSTATUS sret = NT_STATUS_LOGON_FAILURE;
+ NTSTATUS pac_ret;
+ DATA_BLOB auth_data;
+ krb5_context context = NULL;
+ krb5_auth_context auth_context = NULL;
+ krb5_data packet;
+ krb5_ticket *tkt = NULL;
+ krb5_rcache rcache = NULL;
+ krb5_keyblock *keyblock = NULL;
+ time_t authtime;
+ krb5_error_code ret = 0;
+ int flags = 0;
+ krb5_principal host_princ = NULL;
+ krb5_const_principal client_principal = NULL;
+ char *host_princ_s = NULL;
+ BOOL auth_ok = False;
+ BOOL got_replay_mutex = False;
+ BOOL got_auth_data = False;
+
+ ZERO_STRUCT(packet);
+ ZERO_STRUCT(auth_data);
+
+ *principal = NULL;
+ *pac_data = NULL;
+ *ap_rep = data_blob_null;
+ *session_key = data_blob_null;
+
+ initialize_krb5_error_table();
ret = krb5_init_context(&context);
if (ret) {
DEBUG(1,("ads_verify_ticket: krb5_init_context failed (%s)\n", error_message(ret)));
return NT_STATUS_LOGON_FAILURE;
}
- ret = krb5_set_default_realm(context, ads->auth.realm);
+ if (time_offset != 0) {
+ krb5_set_real_time(context, time(NULL) + time_offset, 0);
+ }
+
+ ret = krb5_set_default_realm(context, realm);
if (ret) {
DEBUG(1,("ads_verify_ticket: krb5_set_default_realm failed (%s)\n", error_message(ret)));
- sret = NT_STATUS_LOGON_FAILURE;
goto out;
}
ret = krb5_auth_con_init(context, &auth_context);
if (ret) {
DEBUG(1,("ads_verify_ticket: krb5_auth_con_init failed (%s)\n", error_message(ret)));
- sret = NT_STATUS_LOGON_FAILURE;
goto out;
}
- fstrcpy(myname, global_myname());
- strlower_m(myname);
- asprintf(&host_princ_s, "HOST/%s@%s", myname, lp_realm());
- ret = krb5_parse_name(context, host_princ_s, &host_princ);
- if (ret) {
- DEBUG(1,("ads_verify_ticket: krb5_parse_name(%s) failed (%s)\n",
- host_princ_s, error_message(ret)));
- sret = NT_STATUS_LOGON_FAILURE;
- goto out;
+ krb5_auth_con_getflags( context, auth_context, &flags );
+ if ( !use_replay_cache ) {
+ /* Disable default use of a replay cache */
+ flags &= ~KRB5_AUTH_CONTEXT_DO_TIME;
+ krb5_auth_con_setflags( context, auth_context, flags );
}
- /*
- * JRA. We must set the rcache and the allowed addresses in the auth_context
- * here. This will prevent replay attacks and ensure the client has got a key from
- * the correct IP address.
- */
-
- ret = krb5_get_server_rcache(context, krb5_princ_component(context, host_princ, 0), &rcache);
- if (ret) {
- DEBUG(1,("ads_verify_ticket: krb5_get_server_rcache failed (%s)\n", error_message(ret)));
- sret = NT_STATUS_LOGON_FAILURE;
+ asprintf(&host_princ_s, "%s$", global_myname());
+ if (!host_princ_s) {
goto out;
}
- ret = krb5_auth_con_setrcache(context, auth_context, rcache);
+ strlower_m(host_princ_s);
+ ret = smb_krb5_parse_name(context, host_princ_s, &host_princ);
if (ret) {
- DEBUG(1,("ads_verify_ticket: krb5_auth_con_setrcache failed (%s)\n", error_message(ret)));
- sret = NT_STATUS_LOGON_FAILURE;
+ DEBUG(1,("ads_verify_ticket: smb_krb5_parse_name(%s) failed (%s)\n",
+ host_princ_s, error_message(ret)));
goto out;
}
- /* CIFS doesn't use addresses in tickets. This would breat NAT. JRA */
- if (!(key = (krb5_keyblock *)malloc(sizeof(*key)))) {
- sret = NT_STATUS_NO_MEMORY;
- goto out;
- }
-
- if ((ret = get_kerberos_allowed_etypes(context, &enctypes))) {
- DEBUG(1,("ads_verify_ticket: krb5_get_permitted_enctypes failed (%s)\n",
- error_message(ret)));
- sret = NT_STATUS_LOGON_FAILURE;
- goto out;
- }
+ if ( use_replay_cache ) {
+
+ /* Lock a mutex surrounding the replay as there is no
+ locking in the MIT krb5 code surrounding the replay
+ cache... */
- /* we need to setup a auth context with each possible encoding type in turn */
- for (i=0;enctypes[i];i++) {
- if (create_kerberos_key_from_string(context, host_princ, &password, key, enctypes[i])) {
- continue;
+ if (!grab_server_mutex("replay cache mutex")) {
+ DEBUG(1,("ads_verify_ticket: unable to protect "
+ "replay cache with mutex.\n"));
+ ret = KRB5_CC_IO;
+ goto out;
}
- krb5_auth_con_setuseruserkey(context, auth_context, key);
-
- packet.length = ticket->length;
- packet.data = (krb5_pointer)ticket->data;
+ got_replay_mutex = True;
+
+ /* JRA. We must set the rcache here. This will prevent
+ replay attacks. */
+
+ ret = krb5_get_server_rcache(context,
+ krb5_princ_component(context, host_princ, 0),
+ &rcache);
+ if (ret) {
+ DEBUG(1,("ads_verify_ticket: krb5_get_server_rcache "
+ "failed (%s)\n", error_message(ret)));
+ goto out;
+ }
- if (!(ret = krb5_rd_req(context, &auth_context, &packet,
- NULL, keytab, NULL, &tkt))) {
- DEBUG(10,("ads_verify_ticket: enc type [%u] decrypted message !\n",
- (unsigned int)enctypes[i] ));
- free_kerberos_etypes(context, enctypes);
- auth_ok = True;
- break;
+ ret = krb5_auth_con_setrcache(context, auth_context, rcache);
+ if (ret) {
+ DEBUG(1,("ads_verify_ticket: krb5_auth_con_setrcache "
+ "failed (%s)\n", error_message(ret)));
+ goto out;
}
-
- DEBUG((ret != KRB5_BAD_ENCTYPE) ? 3 : 10,
- ("ads_verify_ticket: enc type [%u] failed to decrypt with error %s\n",
- (unsigned int)enctypes[i], error_message(ret)));
}
+ /* Try secrets.tdb first and fallback to the krb5.keytab if
+ necessary */
+
+ auth_ok = ads_secrets_verify_ticket(context, auth_context, host_princ,
+ ticket, &tkt, &keyblock, &ret);
+
+ if (!auth_ok && lp_use_kerberos_keytab()) {
+ auth_ok = ads_keytab_verify_ticket(context, auth_context,
+ ticket, &tkt, &keyblock, &ret);
+ }
+
+ if ( use_replay_cache ) {
+ release_server_mutex();
+ got_replay_mutex = False;
+#if 0
+ /* Heimdal leaks here, if we fix the leak, MIT crashes */
+ if (rcache) {
+ krb5_rc_close(context, rcache);
+ }
+#endif
+ }
+
if (!auth_ok) {
DEBUG(3,("ads_verify_ticket: krb5_rd_req with auth failed (%s)\n",
error_message(ret)));
- sret = NT_STATUS_LOGON_FAILURE;
+ /* Try map the error return in case it's something like
+ * a clock skew error.
+ */
+ sret = krb5_to_nt_status(ret);
+ if (NT_STATUS_IS_OK(sret) || NT_STATUS_EQUAL(sret,NT_STATUS_UNSUCCESSFUL)) {
+ sret = NT_STATUS_LOGON_FAILURE;
+ }
+ DEBUG(10,("ads_verify_ticket: returning error %s\n",
+ nt_errstr(sret) ));
goto out;
- }
+ }
+
+ authtime = get_authtime_from_tkt(tkt);
+ client_principal = get_principal_from_tkt(tkt);
ret = krb5_mk_rep(context, auth_context, &packet);
if (ret) {
DEBUG(3,("ads_verify_ticket: Failed to generate mutual authentication reply (%s)\n",
error_message(ret)));
- sret = NT_STATUS_LOGON_FAILURE;
goto out;
}
*ap_rep = data_blob(packet.data, packet.length);
- free(packet.data);
+ if (packet.data) {
+ kerberos_free_data_contents(context, &packet);
+ ZERO_STRUCT(packet);
+ }
get_krb5_smb_session_key(context, auth_context, session_key, True);
-#ifdef DEBUG_PASSWORD
- DEBUG(10,("SMB session key (from ticket) follows:\n"));
- dump_data(10, session_key, 16);
-#endif
+ dump_data_pw("SMB session key (from ticket)\n", session_key->data, session_key->length);
#if 0
file_save("/tmp/ticket.dat", ticket->data, ticket->length);
#endif
- get_auth_data_from_tkt(auth_data, tkt);
+ /* continue when no PAC is retrieved or we couldn't decode the PAC
+ (like accounts that have the UF_NO_AUTH_DATA_REQUIRED flag set, or
+ Kerberos tickets encrypted using a DES key) - Guenther */
- {
- TALLOC_CTX *ctx = talloc_init("pac data");
- decode_pac_data(auth_data, ctx);
- talloc_destroy(ctx);
+ got_auth_data = get_auth_data_from_tkt(mem_ctx, &auth_data, tkt);
+ if (!got_auth_data) {
+ DEBUG(3,("ads_verify_ticket: did not retrieve auth data. continuing without PAC\n"));
+ }
+
+ if (got_auth_data && pac_data != NULL) {
+
+ pac_ret = decode_pac_data(mem_ctx, &auth_data, context, keyblock, client_principal, authtime, pac_data);
+ if (!NT_STATUS_IS_OK(pac_ret)) {
+ DEBUG(3,("ads_verify_ticket: failed to decode PAC_DATA: %s\n", nt_errstr(pac_ret)));
+ *pac_data = NULL;
+ }
+ data_blob_free(&auth_data);
}
#if 0
+#if defined(HAVE_KRB5_TKT_ENC_PART2)
+ /* MIT */
if (tkt->enc_part2) {
file_save("/tmp/authdata.dat",
tkt->enc_part2->authorization_data[0]->contents,
tkt->enc_part2->authorization_data[0]->length);
+ }
+#else
+ /* Heimdal */
+ if (tkt->ticket.authorization_data) {
+ file_save("/tmp/authdata.dat",
+ tkt->ticket.authorization_data->val->ad_data.data,
+ tkt->ticket.authorization_data->val->ad_data.length);
+ }
+#endif
#endif
- if ((ret = krb5_unparse_name(context, get_principal_from_tkt(tkt),
- principal))) {
- DEBUG(3,("ads_verify_ticket: krb5_unparse_name failed (%s)\n",
+ if ((ret = smb_krb5_unparse_name(context, client_principal, principal))) {
+ DEBUG(3,("ads_verify_ticket: smb_krb5_unparse_name failed (%s)\n",
error_message(ret)));
sret = NT_STATUS_LOGON_FAILURE;
goto out;
out:
- if (!NT_STATUS_IS_OK(sret))
- data_blob_free(auth_data);
+ if (got_replay_mutex) {
+ release_server_mutex();
+ }
+
+ if (!NT_STATUS_IS_OK(sret)) {
+ data_blob_free(&auth_data);
+ }
- if (!NT_STATUS_IS_OK(sret))
+ if (!NT_STATUS_IS_OK(sret)) {
data_blob_free(ap_rep);
+ }
+
+ if (host_princ) {
+ krb5_free_principal(context, host_princ);
+ }
+
+ if (keyblock) {
+ krb5_free_keyblock(context, keyblock);
+ }
+
+ if (tkt != NULL) {
+ krb5_free_ticket(context, tkt);
+ }
SAFE_FREE(host_princ_s);
- SAFE_FREE(password_s);
- if (auth_context)
+ if (auth_context) {
krb5_auth_con_free(context, auth_context);
+ }
- if (context)
+ if (context) {
krb5_free_context(context);
+ }
return sret;
}
git.samba.org / ira / wip.git / blobdiff