diff options
Diffstat (limited to 'source4/smb_server/smb/negprot.c')
| -rw-r--r-- | source4/smb_server/smb/negprot.c | 564 |
1 files changed, 564 insertions, 0 deletions
diff --git a/source4/smb_server/smb/negprot.c b/source4/smb_server/smb/negprot.c new file mode 100644 index 0000000..ad400a0 --- /dev/null +++ b/source4/smb_server/smb/negprot.c @@ -0,0 +1,564 @@ +/* + Unix SMB/CIFS implementation. + negprot reply code + Copyright (C) Andrew Tridgell 1992-1998 + + 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/filesys.h" +#include "auth/credentials/credentials.h" +#include "auth/gensec/gensec.h" +#include "auth/auth.h" +#include "smb_server/smb_server.h" +#include "libcli/smb2/smb2.h" +#include "smb_server/smb2/smb2_server.h" +#include "samba/service_stream.h" +#include "lib/stream/packet.h" +#include "param/param.h" + + +/* initialise the auth_context for this server and return the cryptkey */ +static NTSTATUS get_challenge(struct smbsrv_connection *smb_conn, uint8_t buff[8]) +{ + NTSTATUS nt_status; + + /* multiple negprots are not permitted */ + if (smb_conn->negotiate.auth_context) { + DEBUG(3,("get challenge: is this a secondary negprot? auth_context is non-NULL!\n")); + return NT_STATUS_FOOBAR; + } + + DEBUG(10, ("get challenge: creating negprot_global_auth_context\n")); + + nt_status = auth_context_create(smb_conn, + smb_conn->connection->event.ctx, + smb_conn->connection->msg_ctx, + smb_conn->lp_ctx, + &smb_conn->negotiate.auth_context); + if (!NT_STATUS_IS_OK(nt_status)) { + DEBUG(0, ("auth_context_create() returned %s\n", nt_errstr(nt_status))); + return nt_status; + } + + nt_status = auth_get_challenge(smb_conn->negotiate.auth_context, buff); + if (!NT_STATUS_IS_OK(nt_status)) { + DEBUG(0, ("auth_get_challenge() returned %s\n", nt_errstr(nt_status))); + return nt_status; + } + + return NT_STATUS_OK; +} + +/**************************************************************************** + Reply for the core protocol. +****************************************************************************/ +static void reply_corep(struct smbsrv_request *req, uint16_t choice) +{ + smbsrv_setup_reply(req, 1, 0); + + SSVAL(req->out.vwv, VWV(0), choice); + + req->smb_conn->negotiate.protocol = PROTOCOL_CORE; + + if (req->smb_conn->signing.mandatory_signing) { + smbsrv_terminate_connection(req->smb_conn, + "CORE does not support SMB signing, and it is mandatory\n"); + return; + } + + smbsrv_send_reply(req); +} + +/**************************************************************************** + Reply for the coreplus protocol. +this is quite incomplete - we only fill in a small part of the reply, but as nobody uses +this any more it probably doesn't matter +****************************************************************************/ +static void reply_coreplus(struct smbsrv_request *req, uint16_t choice) +{ + uint16_t raw; + if (lpcfg_async_smb_echo_handler(req->smb_conn->lp_ctx)) { + raw = 0; + } else { + raw = (lpcfg_read_raw(req->smb_conn->lp_ctx)?1:0) | + (lpcfg_write_raw(req->smb_conn->lp_ctx)?2:0); + } + + smbsrv_setup_reply(req, 13, 0); + + /* Reply, SMBlockread, SMBwritelock supported. */ + SCVAL(req->out.hdr,HDR_FLG, + CVAL(req->out.hdr, HDR_FLG) | FLAG_SUPPORT_LOCKREAD); + + SSVAL(req->out.vwv, VWV(0), choice); + SSVAL(req->out.vwv, VWV(1), 0x1); /* user level security, don't encrypt */ + + /* tell redirector we support + readbraw and writebraw (possibly) */ + SSVAL(req->out.vwv, VWV(5), raw); + + req->smb_conn->negotiate.protocol = PROTOCOL_COREPLUS; + + if (req->smb_conn->signing.mandatory_signing) { + smbsrv_terminate_connection(req->smb_conn, + "COREPLUS does not support SMB signing, and it is mandatory\n"); + return; + } + + smbsrv_send_reply(req); +} + +/**************************************************************************** + Reply for the lanman 1.0 protocol. +****************************************************************************/ +static void reply_lanman1(struct smbsrv_request *req, uint16_t choice) +{ + int secword=0; + time_t t = req->request_time.tv_sec; + uint16_t raw; + + if (lpcfg_async_smb_echo_handler(req->smb_conn->lp_ctx)) { + raw = 0; + } else { + raw = (lpcfg_read_raw(req->smb_conn->lp_ctx)?1:0) | + (lpcfg_write_raw(req->smb_conn->lp_ctx)?2:0); + } + + req->smb_conn->negotiate.encrypted_passwords = lpcfg_encrypt_passwords(req->smb_conn->lp_ctx); + + if (req->smb_conn->negotiate.encrypted_passwords) + secword |= NEGOTIATE_SECURITY_CHALLENGE_RESPONSE; + + req->smb_conn->negotiate.protocol = PROTOCOL_LANMAN1; + + smbsrv_setup_reply(req, 13, req->smb_conn->negotiate.encrypted_passwords ? 8 : 0); + + /* SMBlockread, SMBwritelock supported. */ + SCVAL(req->out.hdr,HDR_FLG, + CVAL(req->out.hdr, HDR_FLG) | FLAG_SUPPORT_LOCKREAD); + + SSVAL(req->out.vwv, VWV(0), choice); + SSVAL(req->out.vwv, VWV(1), secword); + SSVAL(req->out.vwv, VWV(2), req->smb_conn->negotiate.max_recv); + SSVAL(req->out.vwv, VWV(3), lpcfg_max_mux(req->smb_conn->lp_ctx)); + SSVAL(req->out.vwv, VWV(4), 1); + SSVAL(req->out.vwv, VWV(5), raw); + SIVAL(req->out.vwv, VWV(6), req->smb_conn->connection->server_id.pid); + srv_push_dos_date(req->smb_conn, req->out.vwv, VWV(8), t); + SSVAL(req->out.vwv, VWV(10), req->smb_conn->negotiate.zone_offset/60); + SIVAL(req->out.vwv, VWV(11), 0); /* reserved */ + + /* Create a token value and add it to the outgoing packet. */ + if (req->smb_conn->negotiate.encrypted_passwords) { + NTSTATUS nt_status; + + SSVAL(req->out.vwv, VWV(11), 8); + + nt_status = get_challenge(req->smb_conn, req->out.data); + if (!NT_STATUS_IS_OK(nt_status)) { + smbsrv_terminate_connection(req->smb_conn, "LANMAN1 get_challenge failed\n"); + return; + } + } + + if (req->smb_conn->signing.mandatory_signing) { + smbsrv_terminate_connection(req->smb_conn, + "LANMAN1 does not support SMB signing, and it is mandatory\n"); + return; + } + + smbsrv_send_reply(req); +} + +/**************************************************************************** + Reply for the lanman 2.0 protocol. +****************************************************************************/ +static void reply_lanman2(struct smbsrv_request *req, uint16_t choice) +{ + int secword=0; + time_t t = req->request_time.tv_sec; + uint16_t raw; + if (lpcfg_async_smb_echo_handler(req->smb_conn->lp_ctx)) { + raw = 0; + } else { + raw = (lpcfg_read_raw(req->smb_conn->lp_ctx)?1:0) | + (lpcfg_write_raw(req->smb_conn->lp_ctx)?2:0); + } + + req->smb_conn->negotiate.encrypted_passwords = lpcfg_encrypt_passwords(req->smb_conn->lp_ctx); + + if (req->smb_conn->negotiate.encrypted_passwords) + secword |= NEGOTIATE_SECURITY_CHALLENGE_RESPONSE; + + req->smb_conn->negotiate.protocol = PROTOCOL_LANMAN2; + + smbsrv_setup_reply(req, 13, 0); + + SSVAL(req->out.vwv, VWV(0), choice); + SSVAL(req->out.vwv, VWV(1), secword); + SSVAL(req->out.vwv, VWV(2), req->smb_conn->negotiate.max_recv); + SSVAL(req->out.vwv, VWV(3), lpcfg_max_mux(req->smb_conn->lp_ctx)); + SSVAL(req->out.vwv, VWV(4), 1); + SSVAL(req->out.vwv, VWV(5), raw); + SIVAL(req->out.vwv, VWV(6), req->smb_conn->connection->server_id.pid); + srv_push_dos_date(req->smb_conn, req->out.vwv, VWV(8), t); + SSVAL(req->out.vwv, VWV(10), req->smb_conn->negotiate.zone_offset/60); + SIVAL(req->out.vwv, VWV(11), 0); + + /* Create a token value and add it to the outgoing packet. */ + if (req->smb_conn->negotiate.encrypted_passwords) { + SSVAL(req->out.vwv, VWV(11), 8); + req_grow_data(req, 8); + get_challenge(req->smb_conn, req->out.data); + } + + req_push_str(req, NULL, lpcfg_workgroup(req->smb_conn->lp_ctx), -1, STR_TERMINATE); + + if (req->smb_conn->signing.mandatory_signing) { + smbsrv_terminate_connection(req->smb_conn, + "LANMAN2 does not support SMB signing, and it is mandatory\n"); + return; + } + + smbsrv_send_reply(req); +} + +static void reply_nt1_orig(struct smbsrv_request *req) +{ + /* Create a token value and add it to the outgoing packet. */ + if (req->smb_conn->negotiate.encrypted_passwords) { + req_grow_data(req, 8); + /* note that we do not send a challenge at all if + we are using plaintext */ + get_challenge(req->smb_conn, req->out.ptr); + req->out.ptr += 8; + SCVAL(req->out.vwv+1, VWV(16), 8); + } + req_push_str(req, NULL, lpcfg_workgroup(req->smb_conn->lp_ctx), -1, STR_UNICODE|STR_TERMINATE|STR_NOALIGN); + req_push_str(req, NULL, lpcfg_netbios_name(req->smb_conn->lp_ctx), -1, STR_UNICODE|STR_TERMINATE|STR_NOALIGN); + DEBUG(3,("not using extended security (SPNEGO or NTLMSSP)\n")); +} + +/* + try to determine if the filesystem supports large files +*/ +static bool large_file_support(const char *path) +{ + int fd; + ssize_t ret; + char c; + + fd = open(path, O_RDWR|O_CREAT, 0600); + unlink(path); + if (fd == -1) { + /* have to assume large files are OK */ + return true; + } + ret = pread(fd, &c, 1, ((uint64_t)1)<<32); + close(fd); + return ret == 0; +} + +/**************************************************************************** + Reply for the nt protocol. +****************************************************************************/ +static void reply_nt1(struct smbsrv_request *req, uint16_t choice) +{ + /* dual names + lock_and_read + nt SMBs + remote API calls */ + int capabilities; + int secword=0; + time_t t = req->request_time.tv_sec; + NTTIME nttime; + bool negotiate_spnego = false; + char *large_test_path; + + unix_to_nt_time(&nttime, t); + + capabilities = + CAP_NT_FIND | CAP_LOCK_AND_READ | + CAP_LEVEL_II_OPLOCKS | CAP_NT_SMBS | CAP_RPC_REMOTE_APIS; + + req->smb_conn->negotiate.encrypted_passwords = lpcfg_encrypt_passwords(req->smb_conn->lp_ctx); + + /* do spnego in user level security if the client + supports it and we can do encrypted passwords */ + + if (req->smb_conn->negotiate.encrypted_passwords && + (req->flags2 & FLAGS2_EXTENDED_SECURITY)) { + negotiate_spnego = true; + capabilities |= CAP_EXTENDED_SECURITY; + } + + if (lpcfg_large_readwrite(req->smb_conn->lp_ctx)) { + capabilities |= CAP_LARGE_READX | CAP_LARGE_WRITEX | CAP_W2K_SMBS; + } + + large_test_path = lpcfg_lock_path(req, req->smb_conn->lp_ctx, "large_test.dat"); + if (large_file_support(large_test_path)) { + capabilities |= CAP_LARGE_FILES; + } + + if (!lpcfg_async_smb_echo_handler(req->smb_conn->lp_ctx) && + lpcfg_read_raw(req->smb_conn->lp_ctx) && + lpcfg_write_raw(req->smb_conn->lp_ctx)) { + capabilities |= CAP_RAW_MODE; + } + + /* allow for disabling unicode */ + if (lpcfg_unicode(req->smb_conn->lp_ctx)) { + capabilities |= CAP_UNICODE; + } + + if (lpcfg_nt_status_support(req->smb_conn->lp_ctx)) { + capabilities |= CAP_STATUS32; + } + + if (lpcfg_host_msdfs(req->smb_conn->lp_ctx)) { + capabilities |= CAP_DFS; + } + + secword |= NEGOTIATE_SECURITY_USER_LEVEL; + + if (req->smb_conn->negotiate.encrypted_passwords) { + secword |= NEGOTIATE_SECURITY_CHALLENGE_RESPONSE; + } + + if (req->smb_conn->signing.allow_smb_signing) { + secword |= NEGOTIATE_SECURITY_SIGNATURES_ENABLED; + } + + if (req->smb_conn->signing.mandatory_signing) { + secword |= NEGOTIATE_SECURITY_SIGNATURES_REQUIRED; + } + + req->smb_conn->negotiate.protocol = PROTOCOL_NT1; + + smbsrv_setup_reply(req, 17, 0); + + SSVAL(req->out.vwv, VWV(0), choice); + SCVAL(req->out.vwv, VWV(1), secword); + + /* notice the strange +1 on vwv here? That's because + this is the one and only SMB packet that is malformed in + the specification - all the command words after the secword + are offset by 1 byte */ + SSVAL(req->out.vwv+1, VWV(1), lpcfg_max_mux(req->smb_conn->lp_ctx)); + SSVAL(req->out.vwv+1, VWV(2), 1); /* num vcs */ + SIVAL(req->out.vwv+1, VWV(3), req->smb_conn->negotiate.max_recv); + SIVAL(req->out.vwv+1, VWV(5), 0x10000); /* raw size. full 64k */ + SIVAL(req->out.vwv+1, VWV(7), req->smb_conn->connection->server_id.pid); /* session key */ + + SIVAL(req->out.vwv+1, VWV(9), capabilities); + push_nttime(req->out.vwv+1, VWV(11), nttime); + SSVALS(req->out.vwv+1,VWV(15), req->smb_conn->negotiate.zone_offset/60); + + if (!negotiate_spnego) { + reply_nt1_orig(req); + } else { + struct cli_credentials *server_credentials; + struct gensec_security *gensec_security; + DATA_BLOB null_data_blob = data_blob(NULL, 0); + DATA_BLOB blob = data_blob_null; + const char *oid; + NTSTATUS nt_status; + + server_credentials = + cli_credentials_init_server(req, req->smb_conn->lp_ctx); + if (server_credentials == NULL) { + DBG_DEBUG("Failed to obtain server credentials, " + "perhaps a standalone server?\n"); + /* + * Create anon server credentials for for the + * spoolss.notify test. + */ + server_credentials = cli_credentials_init_anon(req); + if (server_credentials == NULL) { + smbsrv_terminate_connection(req->smb_conn, + "Failed to init server credentials\n"); + return; + } + } + + nt_status = samba_server_gensec_start(req, + req->smb_conn->connection->event.ctx, + req->smb_conn->connection->msg_ctx, + req->smb_conn->lp_ctx, + server_credentials, + "cifs", + &gensec_security); + + if (!NT_STATUS_IS_OK(nt_status)) { + DEBUG(0, ("Failed to start GENSEC: %s\n", nt_errstr(nt_status))); + smbsrv_terminate_connection(req->smb_conn, "Failed to start GENSEC\n"); + return; + } + + if (req->smb_conn->negotiate.auth_context) { + smbsrv_terminate_connection(req->smb_conn, "reply_nt1: is this a secondary negprot? auth_context is non-NULL!\n"); + return; + } + req->smb_conn->negotiate.server_credentials = talloc_reparent(req, req->smb_conn, server_credentials); + + oid = GENSEC_OID_SPNEGO; + nt_status = gensec_start_mech_by_oid(gensec_security, oid); + + if (NT_STATUS_IS_OK(nt_status)) { + /* Get and push the proposed OID list into the packets */ + nt_status = gensec_update(gensec_security, req, + null_data_blob, &blob); + + if (!NT_STATUS_IS_OK(nt_status) && !NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) { + DEBUG(1, ("Failed to get SPNEGO to give us the first token: %s\n", nt_errstr(nt_status))); + } + } + + if (NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) { + DEBUG(3,("using SPNEGO\n")); + } else { + DEBUG(5, ("Failed to start SPNEGO, falling back to NTLMSSP only: %s\n", nt_errstr(nt_status))); + oid = GENSEC_OID_NTLMSSP; + nt_status = gensec_start_mech_by_oid(gensec_security, oid); + + if (!NT_STATUS_IS_OK(nt_status)) { + DEBUG(0, ("Failed to start SPNEGO as well as NTLMSSP fallback: %s\n", nt_errstr(nt_status))); + reply_nt1_orig(req); + return; + } + /* NTLMSSP is a client-first exchange */ + blob = data_blob(NULL, 0); + DEBUG(3,("using raw-NTLMSSP\n")); + } + + req->smb_conn->negotiate.oid = oid; + + req_grow_data(req, blob.length + 16); + /* a NOT very random guid, perhaps we should get it + * from the credentials (kitchen sink...) */ + memset(req->out.ptr, '\0', 16); + req->out.ptr += 16; + + memcpy(req->out.ptr, blob.data, blob.length); + SCVAL(req->out.vwv+1, VWV(16), blob.length + 16); + req->out.ptr += blob.length; + } + + smbsrv_send_reply_nosign(req); +} + +/**************************************************************************** + Reply for the SMB2 2.001 protocol +****************************************************************************/ +static void reply_smb2(struct smbsrv_request *req, uint16_t choice) +{ + struct smbsrv_connection *smb_conn = req->smb_conn; + NTSTATUS status; + + talloc_free(smb_conn->sessions.idtree_vuid); + ZERO_STRUCT(smb_conn->sessions); + talloc_free(smb_conn->smb_tcons.idtree_tid); + ZERO_STRUCT(smb_conn->smb_tcons); + ZERO_STRUCT(smb_conn->signing); + + /* reply with a SMB2 packet */ + status = smbsrv_init_smb2_connection(smb_conn); + if (!NT_STATUS_IS_OK(status)) { + smbsrv_terminate_connection(smb_conn, nt_errstr(status)); + talloc_free(req); + return; + } + packet_set_callback(smb_conn->packet, smbsrv_recv_smb2_request); + smb2srv_reply_smb_negprot(req); + req = NULL; +} + +/* List of supported protocols, most desired first */ +static const struct { + const char *proto_name; + const char *short_name; + void (*proto_reply_fn)(struct smbsrv_request *req, uint16_t choice); + int protocol_level; +} supported_protocols[] = { + {"SMB 2.002", "SMB2", reply_smb2, PROTOCOL_SMB2_02}, + {"NT LANMAN 1.0", "NT1", reply_nt1, PROTOCOL_NT1}, + {"NT LM 0.12", "NT1", reply_nt1, PROTOCOL_NT1}, + {"LANMAN2.1", "LANMAN2", reply_lanman2, PROTOCOL_LANMAN2}, + {"LM1.2X002", "LANMAN2", reply_lanman2, PROTOCOL_LANMAN2}, + {"Samba", "LANMAN2", reply_lanman2, PROTOCOL_LANMAN2}, + {"DOS LM1.2X002", "LANMAN2", reply_lanman2, PROTOCOL_LANMAN2}, + {"Windows for Workgroups 3.1a", "LANMAN1", reply_lanman1, PROTOCOL_LANMAN1}, + {"LANMAN1.0", "LANMAN1", reply_lanman1, PROTOCOL_LANMAN1}, + {"MICROSOFT NETWORKS 3.0", "LANMAN1", reply_lanman1, PROTOCOL_LANMAN1}, + {"MICROSOFT NETWORKS 1.03", "COREPLUS", reply_coreplus, PROTOCOL_COREPLUS}, + {"PC NETWORK PROGRAM 1.0", "CORE", reply_corep, PROTOCOL_CORE}, + {NULL,NULL,NULL,0}, +}; + +/**************************************************************************** + Reply to a negprot. +****************************************************************************/ + +void smbsrv_reply_negprot(struct smbsrv_request *req) +{ + int protocol; + uint8_t *p; + uint32_t protos_count = 0; + const char **protos = NULL; + + if (req->smb_conn->negotiate.done_negprot) { + smbsrv_terminate_connection(req->smb_conn, "multiple negprot's are not permitted"); + return; + } + req->smb_conn->negotiate.done_negprot = true; + + p = req->in.data; + while (true) { + size_t len; + + protos = talloc_realloc(req, protos, const char *, protos_count + 1); + if (!protos) { + smbsrv_terminate_connection(req->smb_conn, nt_errstr(NT_STATUS_NO_MEMORY)); + return; + } + protos[protos_count] = NULL; + len = req_pull_ascii4(&req->in.bufinfo, &protos[protos_count], p, STR_ASCII|STR_TERMINATE); + p += len; + if (len == 0 || !protos[protos_count]) break; + + DEBUG(5,("Requested protocol [%d][%s]\n", protos_count, protos[protos_count])); + protos_count++; + } + + /* Check for protocols, most desirable first */ + for (protocol = 0; supported_protocols[protocol].proto_name; protocol++) { + int i; + + if (supported_protocols[protocol].protocol_level > lpcfg_server_max_protocol(req->smb_conn->lp_ctx)) + continue; + if (supported_protocols[protocol].protocol_level < lpcfg_server_min_protocol(req->smb_conn->lp_ctx)) + continue; + + for (i = 0; i < protos_count; i++) { + if (strcmp(supported_protocols[protocol].proto_name, protos[i]) != 0) continue; + + supported_protocols[protocol].proto_reply_fn(req, i); + DEBUG(3,("Selected protocol [%d][%s]\n", + i, supported_protocols[protocol].proto_name)); + return; + } + } + + smbsrv_terminate_connection(req->smb_conn, "No protocol supported !"); +} |