From 2c95244f1115c87a8ec3101427680a834d71ceaf Mon Sep 17 00:00:00 2001 From: Andrew Bartlett Date: Mon, 5 May 2008 13:21:18 +1000 Subject: [PATCH] Add a new implementation of security=server. This is not intended for general use, and will not be easily exposed (if I have anything to do with it), but should allow the CIFS proxy to re-use the connection. A work in progress. Andrew Bartlett (This used to be commit a1e60ebc6d1e794011df5f69f691f4ec8622e991) --- source4/auth/auth.c | 1 + source4/auth/auth_server.c | 558 ++++++++++++++----------------------- source4/auth/config.mk | 12 + 3 files changed, 216 insertions(+), 355 deletions(-) diff --git a/source4/auth/auth.c b/source4/auth/auth.c index 6c86cf2d7ce..b74a4389625 100644 --- a/source4/auth/auth.c +++ b/source4/auth/auth.c @@ -521,6 +521,7 @@ _PUBLIC_ NTSTATUS auth_init(void) extern NTSTATUS auth_anonymous_init(void); extern NTSTATUS auth_unix_init(void); extern NTSTATUS auth_sam_init(void); + extern NTSTATUS auth_server_init(void); init_module_fn static_init[] = { STATIC_auth_MODULES }; diff --git a/source4/auth/auth_server.c b/source4/auth/auth_server.c index f200ad9665d..be5f84fe39a 100644 --- a/source4/auth/auth_server.c +++ b/source4/auth/auth_server.c @@ -1,9 +1,10 @@ /* Unix SMB/CIFS implementation. - Authenticate to a remote server - Copyright (C) Andrew Tridgell 1992-1998 - Copyright (C) Andrew Bartlett 2001 - + Authenticate by using a remote server + Copyright (C) Andrew Bartlett 2001-2002, 2008 + Copyright (C) Jelmer Vernooij 2002 + Copyright (C) Stefan Metzmacher 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 @@ -19,359 +20,206 @@ */ #include "includes.h" +#include "auth/auth.h" +#include "auth/auth_proto.h" +#include "auth/credentials/credentials.h" +#include "libcli/security/security.h" +#include "librpc/gen_ndr/ndr_samr.h" +#include "libcli/smb_composite/smb_composite.h" +#include "param/param.h" +#include "libcli/resolve/resolve.h" -/**************************************************************************** - Support for server level security. -****************************************************************************/ +/* This version of 'security=server' rewirtten from scratch for Samba4 + * libraries in 2008 */ -static struct smbcli_state *server_cryptkey(TALLOC_CTX *mem_ctx, bool unicode, int maxprotocol, struct resolve_context *resolve_ctx) + +static NTSTATUS server_want_check(struct auth_method_context *ctx, + TALLOC_CTX *mem_ctx, + const struct auth_usersupplied_info *user_info) { - struct smbcli_state *cli = NULL; - fstring desthost; - struct in_addr dest_ip; - const char *p; - char *pserver; - bool connected_ok = false; - - if (!(cli = smbcli_initialise(cli))) - return NULL; - - /* security = server just can't function with spnego */ - cli->use_spnego = false; - - pserver = talloc_strdup(mem_ctx, lp_passwordserver()); - p = pserver; - - while(next_token( &p, desthost, LIST_SEP, sizeof(desthost))) { - strupper(desthost); - - if(!resolve_name(resolve_ctx, desthost, &dest_ip, 0x20)) { - DEBUG(1,("server_cryptkey: Can't resolve address for %s\n",desthost)); - continue; - } - - if (ismyip(dest_ip)) { - DEBUG(1,("Password server loop - disabling password server %s\n",desthost)); - continue; - } - - /* we use a mutex to prevent two connections at once - when a - Win2k PDC get two connections where one hasn't completed a - session setup yet it will send a TCP reset to the first - connection (tridge) */ - - if (!grab_server_mutex(desthost)) { - return NULL; - } - - if (smbcli_connect(cli, desthost, &dest_ip)) { - DEBUG(3,("connected to password server %s\n",desthost)); - connected_ok = true; - break; - } - } - - if (!connected_ok) { - release_server_mutex(); - DEBUG(0,("password server not available\n")); - talloc_free(cli); - return NULL; - } - - if (!attempt_netbios_session_request(cli, lp_netbios_name(), - desthost, &dest_ip)) { - release_server_mutex(); - DEBUG(1,("password server fails session request\n")); - talloc_free(cli); - return NULL; - } - - if (strequal(desthost,myhostname(mem_ctx))) { - exit_server("Password server loop!"); - } - - DEBUG(3,("got session\n")); - - if (!smbcli_negprot(cli, unicode, maxprotocol)) { - DEBUG(1,("%s rejected the negprot\n",desthost)); - release_server_mutex(); - talloc_free(cli); - return NULL; - } - - if (cli->protocol < PROTOCOL_LANMAN2 || - !(cli->sec_mode & NEGOTIATE_SECURITY_USER_LEVEL)) { - DEBUG(1,("%s isn't in user level security mode\n",desthost)); - release_server_mutex(); - talloc_free(cli); - return NULL; - } - - /* Get the first session setup done quickly, to avoid silly - Win2k bugs. (The next connection to the server will kill - this one... - */ - - if (!smbcli_session_setup(cli, "", "", 0, "", 0, - "")) { - DEBUG(0,("%s rejected the initial session setup (%s)\n", - desthost, smbcli_errstr(cli))); - release_server_mutex(); - talloc_free(cli); - return NULL; - } - - release_server_mutex(); - - DEBUG(3,("password server OK\n")); - - return cli; -} - -/**************************************************************************** - Clean up our allocated cli. -****************************************************************************/ - -static void free_server_private_data(void **private_data_pointer) -{ - struct smbcli_state **cli = (struct smbcli_state **)private_data_pointer; - if (*cli && (*cli)->initialised) { - talloc_free(*cli); - } -} - -/**************************************************************************** - Get the challenge out of a password server. -****************************************************************************/ - -static DATA_BLOB auth_get_challenge_server(const struct auth_context *auth_context, - void **my_private_data, - TALLOC_CTX *mem_ctx) -{ - struct smbcli_state *cli = server_cryptkey(mem_ctx, lp_cli_maxprotocol(auth_context->lp_ctx)); - - if (cli) { - DEBUG(3,("using password server validation\n")); - - if ((cli->sec_mode & NEGOTIATE_SECURITY_CHALLENGE_RESPONSE) == 0) { - /* We can't work with unencrypted password servers - unless 'encrypt passwords = no' */ - DEBUG(5,("make_auth_info_server: Server is unencrypted, no challenge available..\n")); - - /* However, it is still a perfectly fine connection - to pass that unencrypted password over */ - *my_private_data = (void *)cli; - return data_blob(NULL, 0); - - } else if (cli->secblob.length < 8) { - /* We can't do much if we don't get a full challenge */ - DEBUG(2,("make_auth_info_server: Didn't receive a full challenge from server\n")); - talloc_free(cli); - return data_blob(NULL, 0); - } - - *my_private_data = (void *)cli; - - /* The return must be allocated on the caller's mem_ctx, as our own will be - destoyed just after the call. */ - return data_blob_talloc(auth_context->mem_ctx, cli->secblob.data,8); - } else { - return data_blob(NULL, 0); - } -} - - -/**************************************************************************** - Check for a valid username and password in security=server mode. - - Validate a password with the password server. -****************************************************************************/ - -static NTSTATUS check_smbserver_security(const struct auth_context *auth_context, - void *my_private_data, - TALLOC_CTX *mem_ctx, - const auth_usersupplied_info *user_info, - auth_serversupplied_info **server_info) -{ - struct smbcli_state *cli; - static uint8_t badpass[24]; - static fstring baduser; - static bool tested_password_server = false; - static bool bad_password_server = false; - NTSTATUS nt_status = NT_STATUS_LOGON_FAILURE; - bool locally_made_cli = false; - - /* - * Check that the requested domain is not our own machine name. - * If it is, we should never check the PDC here, we use our own local - * password file. - */ - - if (lp_is_myname(auth_context->lp_ctx, user_info->domain.str)) { - DEBUG(3,("check_smbserver_security: Requested domain was for this machine.\n")); - return NT_STATUS_LOGON_FAILURE; - } - - cli = my_private_data; - - if (cli) { - } else { - cli = server_cryptkey(mem_ctx, lp_unicode(auth_context->lp_ctx), lp_cli_maxprotocol(auth_context->lp_ctx), lp_resolve_context(auth_context->lp_ctx)); - locally_made_cli = true; - } - - if (!cli || !cli->initialised) { - DEBUG(1,("password server is not connected (cli not initilised)\n")); - return NT_STATUS_LOGON_FAILURE; - } - - if ((cli->sec_mode & NEGOTIATE_SECURITY_CHALLENGE_RESPONSE) == 0) { - if (user_info->encrypted) { - DEBUG(1,("password server %s is plaintext, but we are encrypted. This just can't work :-(\n", cli->desthost)); - return NT_STATUS_LOGON_FAILURE; - } - } else { - if (memcmp(cli->secblob.data, auth_context->challenge.data, 8) != 0) { - DEBUG(1,("the challenge that the password server (%s) supplied us is not the one we gave our client. This just can't work :-(\n", cli->desthost)); - return NT_STATUS_LOGON_FAILURE; - } - } - - if(badpass[0] == 0) - memset(badpass, 0x1f, sizeof(badpass)); - - if((user_info->nt_resp.length == sizeof(badpass)) && - !memcmp(badpass, user_info->nt_resp.data, sizeof(badpass))) { - /* - * Very unlikely, our random bad password is the same as the users - * password. - */ - memset(badpass, badpass[0]+1, sizeof(badpass)); - } - - if(baduser[0] == 0) { - fstrcpy(baduser, INVALID_USER_PREFIX); - fstrcat(baduser, lp_netbios_name()); - } - - /* - * Attempt a session setup with a totally incorrect password. - * If this succeeds with the guest bit *NOT* set then the password - * server is broken and is not correctly setting the guest bit. We - * need to detect this as some versions of NT4.x are broken. JRA. - */ - - /* I sure as hell hope that there aren't servers out there that take - * NTLMv2 and have this bug, as we don't test for that... - * - abartlet@samba.org - */ - - if ((!tested_password_server) && (lp_paranoid_server_security())) { - if (smbcli_session_setup(cli, baduser, (char *)badpass, sizeof(badpass), - (char *)badpass, sizeof(badpass), user_info->domain.str)) { - - /* - * We connected to the password server so we - * can say we've tested it. - */ - tested_password_server = true; - - if ((SVAL(cli->inbuf,smb_vwv2) & 1) == 0) { - DEBUG(0,("server_validate: password server %s allows users as non-guest \ -with a bad password.\n", cli->desthost)); - DEBUG(0,("server_validate: This is broken (and insecure) behaviour. Please do not \ -use this machine as the password server.\n")); - smbcli_ulogoff(cli); - - /* - * Password server has the bug. - */ - bad_password_server = true; - return NT_STATUS_LOGON_FAILURE; - } - smbcli_ulogoff(cli); - } - } else { - - /* - * We have already tested the password server. - * Fail immediately if it has the bug. - */ - - if(bad_password_server) { - DEBUG(0,("server_validate: [1] password server %s allows users as non-guest \ -with a bad password.\n", cli->desthost)); - DEBUG(0,("server_validate: [1] This is broken (and insecure) behaviour. Please do not \ -use this machine as the password server.\n")); - return NT_STATUS_LOGON_FAILURE; - } - } - - /* - * Now we know the password server will correctly set the guest bit, or is - * not guest enabled, we can try with the real password. - */ - - if (!user_info->encrypted) { - /* Plaintext available */ - if (!smbcli_session_setup(cli, user_info->smb_name.str, - (char *)user_info->plaintext_password.data, - user_info->plaintext_password.length, - NULL, 0, - user_info->domain.str)) { - DEBUG(1,("password server %s rejected the password\n", cli->desthost)); - /* Make this smbcli_nt_error() when the conversion is in */ - nt_status = smbcli_nt_error(cli); - } else { - nt_status = NT_STATUS_OK; - } - } else { - if (!smbcli_session_setup(cli, user_info->smb_name.str, - (char *)user_info->lm_resp.data, - user_info->lm_resp.length, - (char *)user_info->nt_resp.data, - user_info->nt_resp.length, - user_info->domain.str)) { - DEBUG(1,("password server %s rejected the password\n", cli->desthost)); - /* Make this smbcli_nt_error() when the conversion is in */ - nt_status = smbcli_nt_error(cli); - } else { - nt_status = NT_STATUS_OK; - } - } - - /* if logged in as guest then reject */ - if ((SVAL(cli->inbuf,smb_vwv2) & 1) != 0) { - DEBUG(1,("password server %s gave us guest only\n", cli->desthost)); - nt_status = NT_STATUS_LOGON_FAILURE; - } - - smbcli_ulogoff(cli); - - if NT_STATUS_IS_OK(nt_status) { - struct passwd *pass = Get_Pwnam(user_info->internal_username.str); - if (pass) { - nt_status = make_server_info_pw(auth_context, server_info, pass); - } else { - nt_status = NT_STATUS_NO_SUCH_USER; - } - } - - if (locally_made_cli) { - talloc_free(cli); - } - - return(nt_status); -} - -NTSTATUS auth_init_smbserver(struct auth_context *auth_context, const char* param, auth_methods **auth_method) -{ - if (!make_auth_methods(auth_context, auth_method)) { - return NT_STATUS_NO_MEMORY; - } - (*auth_method)->name = "smbserver"; - (*auth_method)->auth = check_smbserver_security; - (*auth_method)->get_chal = auth_get_challenge_server; - (*auth_method)->send_keepalive = send_server_keepalive; - (*auth_method)->free_private_data = free_server_private_data; return NT_STATUS_OK; } +/** + * The challenge from the target server, when operating in security=server + **/ +static NTSTATUS server_get_challenge(struct auth_method_context *ctx, TALLOC_CTX *mem_ctx, DATA_BLOB *_blob) +{ + struct smb_composite_connect io; + struct smbcli_options smb_options; + const char **host_list; + NTSTATUS status; + + /* Make a connection to the target server, found by 'password server' in smb.conf */ + + lp_smbcli_options(ctx->auth_ctx->lp_ctx, &smb_options); + + /* Make a negprot, WITHOUT SPNEGO, so we get a challenge nice an easy */ + io.in.options.use_spnego = false; + + /* Hope we don't get * (the default), as this won't work... */ + host_list = lp_passwordserver(ctx->auth_ctx->lp_ctx); + if (!host_list) { + return NT_STATUS_INTERNAL_ERROR; + } + io.in.dest_host = host_list[0]; + if (strequal(io.in.dest_host, "*")) { + return NT_STATUS_INTERNAL_ERROR; + } + io.in.dest_ports = lp_smb_ports(ctx->auth_ctx->lp_ctx); + + io.in.called_name = strupper_talloc(mem_ctx, io.in.dest_host); + + /* We don't want to get as far as the session setup */ + io.in.credentials = NULL; + io.in.service = NULL; + + io.in.workgroup = ""; /* only used with SPNEGO, disabled above */ + + io.in.options = smb_options; + + status = smb_composite_connect(&io, mem_ctx, lp_resolve_context(ctx->auth_ctx->lp_ctx), + ctx->auth_ctx->event_ctx); + if (!NT_STATUS_IS_OK(status)) { + *_blob = io.out.tree->session->transport->negotiate.secblob; + ctx->private_data = talloc_steal(ctx, io.out.tree->session); + } + return NT_STATUS_OK; +} + +/** + * Return an error based on username + * + * This function allows the testing of obsure errors, as well as the generation + * of NT_STATUS -> DOS error mapping tables. + * + * This module is of no value to end-users. + * + * The password is ignored. + * + * @return An NTSTATUS value based on the username + **/ + +static NTSTATUS server_check_password(struct auth_method_context *ctx, + TALLOC_CTX *mem_ctx, + const struct auth_usersupplied_info *user_info, + struct auth_serversupplied_info **_server_info) +{ + NTSTATUS nt_status; + struct auth_serversupplied_info *server_info; + struct cli_credentials *creds; + const char *user; + struct smb_composite_sesssetup session_setup; + + struct smbcli_session *session = talloc_get_type(ctx->private_data, struct smbcli_session); + + creds = cli_credentials_init(mem_ctx); + + NT_STATUS_HAVE_NO_MEMORY(creds); + + cli_credentials_set_username(creds, user_info->client.account_name, CRED_SPECIFIED); + cli_credentials_set_domain(creds, user_info->client.domain_name, CRED_SPECIFIED); + + switch (user_info->password_state) { + case AUTH_PASSWORD_PLAIN: + cli_credentials_set_password(creds, user_info->password.plaintext, + CRED_SPECIFIED); + break; + case AUTH_PASSWORD_HASH: + cli_credentials_set_nt_hash(creds, user_info->password.hash.nt, + CRED_SPECIFIED); + break; + + case AUTH_PASSWORD_RESPONSE: + cli_credentials_set_ntlm_response(creds, &user_info->password.response.lanman, &user_info->password.response.nt, CRED_SPECIFIED); + break; + } + + session_setup.in.sesskey = session->transport->negotiate.sesskey; + session_setup.in.capabilities = session->transport->negotiate.capabilities; + + session_setup.in.credentials = creds; + session_setup.in.workgroup = ""; /* Only used with SPNEGO, which we are not doing */ + + /* Check password with remove server - this should be async some day */ + nt_status = smb_composite_sesssetup(session, &session_setup); + + if (!NT_STATUS_IS_OK(nt_status)) { + return nt_status; + } + + server_info = talloc(mem_ctx, struct auth_serversupplied_info); + NT_STATUS_HAVE_NO_MEMORY(server_info); + + server_info->account_sid = dom_sid_parse_talloc(server_info, SID_NT_ANONYMOUS); + NT_STATUS_HAVE_NO_MEMORY(server_info->account_sid); + + /* is this correct? */ + server_info->primary_group_sid = dom_sid_parse_talloc(server_info, SID_BUILTIN_GUESTS); + NT_STATUS_HAVE_NO_MEMORY(server_info->primary_group_sid); + + server_info->n_domain_groups = 0; + server_info->domain_groups = NULL; + + /* annoying, but the Anonymous really does have a session key, + and it is all zeros! */ + server_info->user_session_key = data_blob(NULL, 0); + server_info->lm_session_key = data_blob(NULL, 0); + + server_info->account_name = talloc_strdup(server_info, user_info->client.account_name); + NT_STATUS_HAVE_NO_MEMORY(server_info->account_name); + + server_info->domain_name = talloc_strdup(server_info, user_info->client.domain_name); + NT_STATUS_HAVE_NO_MEMORY(server_info->domain_name); + + server_info->full_name = NULL; + + server_info->logon_script = talloc_strdup(server_info, ""); + NT_STATUS_HAVE_NO_MEMORY(server_info->logon_script); + + server_info->profile_path = talloc_strdup(server_info, ""); + NT_STATUS_HAVE_NO_MEMORY(server_info->profile_path); + + server_info->home_directory = talloc_strdup(server_info, ""); + NT_STATUS_HAVE_NO_MEMORY(server_info->home_directory); + + server_info->home_drive = talloc_strdup(server_info, ""); + NT_STATUS_HAVE_NO_MEMORY(server_info->home_drive); + + server_info->last_logon = 0; + server_info->last_logoff = 0; + server_info->acct_expiry = 0; + server_info->last_password_change = 0; + server_info->allow_password_change = 0; + server_info->force_password_change = 0; + + server_info->logon_count = 0; + server_info->bad_password_count = 0; + + server_info->acct_flags = ACB_NORMAL; + + server_info->authenticated = false; + + *_server_info = server_info; + + return nt_status; +} + +static const struct auth_operations server_auth_ops = { + .name = "server", + .get_challenge = server_get_challenge, + .want_check = server_want_check, + .check_password = server_check_password +}; + +_PUBLIC_ NTSTATUS auth_server_init(void) +{ + NTSTATUS ret; + + ret = auth_register(&server_auth_ops); + if (!NT_STATUS_IS_OK(ret)) { + DEBUG(0,("Failed to register 'server' auth backend!\n")); + return ret; + } + + return ret; +} diff --git a/source4/auth/config.mk b/source4/auth/config.mk index 7d4678b7ac4..0acb9e30ba8 100644 --- a/source4/auth/config.mk +++ b/source4/auth/config.mk @@ -54,6 +54,18 @@ SUBSYSTEM = auth auth_anonymous_OBJ_FILES = $(addprefix auth/, auth_anonymous.o) +####################### +# Start MODULE auth_anonymous +[MODULE::auth_server] +INIT_FUNCTION = auth_server_init +SUBSYSTEM = auth +PRIVATE_DEPENDENCIES = LIBSAMBA-UTIL LIBCLI_SMB +OUTPUT_TYPE = SHARED_LIBRARY +# End MODULE auth_server +####################### + +auth_server_OBJ_FILES = $(addprefix auth/, auth_server.o) + ####################### # Start MODULE auth_winbind [MODULE::auth_winbind]