zeek/scripts/base/protocols/ldap/main.zeek
Benjamin Bannier d5fd29edcd Prefer explicit construction to coercion in record initialization
While we support initializing records via coercion from an expression
list, e.g.,

    local x: X = [$x1=1, $x2=2];

this can sometimes obscure the code to readers, e.g., when assigning to
value declared and typed elsewhere. The language runtime has a similar
overhead since instead of just constructing a known type it needs to
check at runtime that the coercion from the expression list is valid;
this can be slower than just writing the readible code in the first
place, see #4559.

With this patch we use explicit construction, e.g.,

    local x = X($x1=1, $x2=2);
2025-07-11 16:28:37 -07:00

420 lines
14 KiB
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# See the file "COPYING" in the main distribution directory for copyright.
@load base/frameworks/reporter
@load base/protocols/conn/removal-hooks
@load ./consts
module LDAP;
export {
redef enum Log::ID += { LDAP_LOG, LDAP_SEARCH_LOG };
## TCP ports which should be considered for analysis.
const ports_tcp = { 389/tcp, 3268/tcp } &redef;
## UDP ports which should be considered for analysis.
const ports_udp = { 389/udp } &redef;
## Whether clear text passwords are captured or not.
option default_capture_password = F;
## Whether to log LDAP search attributes or not.
option default_log_search_attributes = F;
## Default logging policy hook for LDAP_LOG.
global log_policy: Log::PolicyHook;
## Default logging policy hook for LDAP_SEARCH_LOG.
global log_policy_search: Log::PolicyHook;
## LDAP finalization hook.
global finalize_ldap: Conn::RemovalHook;
#############################################################################
# This is the format of ldap.log (ldap operations minus search-related)
# Each line represents a unique connection+message_id (requests/responses)
type MessageInfo: record {
# Timestamp for when the event happened.
ts: time &log;
# Unique ID for the connection.
uid: string &log;
# The connection's 4-tuple of endpoint addresses/ports.
id: conn_id &log;
# Message ID
message_id: int &log &optional;
# LDAP version
version: int &log &optional;
# Normalized operation (e.g., bind_request and bind_response to "bind")
opcode: string &log &optional;
# Result code
result: string &log &optional;
# Result diagnostic message
diagnostic_message: string &log &optional;
# Object
object: string &log &optional;
# Argument
argument: string &log &optional;
};
#############################################################################
# This is the format of ldap_search.log (search-related messages only)
# Each line represents a unique connection+message_id (requests/responses)
type SearchInfo: record {
# Timestamp for when the event happened.
ts: time &log;
# Unique ID for the connection.
uid: string &log;
# The connection's 4-tuple of endpoint addresses/ports.
id: conn_id &log;
# Message ID
message_id: int &log &optional;
# sets of search scope and deref alias
scope: string &log &optional;
deref_aliases: string &log &optional;
# Base search objects
base_object: string &log &optional;
# Number of results returned
result_count: count &log &optional;
# Result code of search operation
result: string &log &optional;
# Result diagnostic message
diagnostic_message: string &log &optional;
# A string representation of the search filter used in the query
filter: string &log &optional;
# A list of attributes that were returned in the search
attributes: vector of string &log &optional;
};
type State: record {
messages: table[int] of MessageInfo &optional;
searches: table[int] of SearchInfo &optional;
};
# Event that can be handled to access the ldap record as it is sent on
# to the logging framework.
global log_ldap: event(rec: LDAP::MessageInfo);
global log_ldap_search: event(rec: LDAP::SearchInfo);
}
redef record connection += {
ldap: State &optional;
};
redef likely_server_ports += { LDAP::ports_tcp, LDAP::ports_udp };
#############################################################################
global OPCODES_FINISHED: set[LDAP::ProtocolOpcode] = { LDAP::ProtocolOpcode_BIND_RESPONSE,
LDAP::ProtocolOpcode_UNBIND_REQUEST,
LDAP::ProtocolOpcode_SEARCH_RESULT_DONE,
LDAP::ProtocolOpcode_MODIFY_RESPONSE,
LDAP::ProtocolOpcode_ADD_RESPONSE,
LDAP::ProtocolOpcode_DEL_RESPONSE,
LDAP::ProtocolOpcode_MOD_DN_RESPONSE,
LDAP::ProtocolOpcode_COMPARE_RESPONSE,
LDAP::ProtocolOpcode_ABANDON_REQUEST,
LDAP::ProtocolOpcode_EXTENDED_RESPONSE };
global OPCODES_SEARCH: set[LDAP::ProtocolOpcode] = { LDAP::ProtocolOpcode_SEARCH_REQUEST,
LDAP::ProtocolOpcode_SEARCH_RESULT_ENTRY,
LDAP::ProtocolOpcode_SEARCH_RESULT_DONE,
LDAP::ProtocolOpcode_SEARCH_RESULT_REFERENCE };
#############################################################################
event zeek_init() &priority=5 {
Analyzer::register_for_ports(Analyzer::ANALYZER_LDAP_TCP, LDAP::ports_tcp);
Analyzer::register_for_ports(Analyzer::ANALYZER_LDAP_UDP, LDAP::ports_udp);
Log::create_stream(LDAP::LDAP_LOG, Log::Stream($columns=MessageInfo, $ev=log_ldap, $path="ldap", $policy=log_policy));
Log::create_stream(LDAP::LDAP_SEARCH_LOG, Log::Stream($columns=SearchInfo, $ev=log_ldap_search, $path="ldap_search", $policy=log_policy_search));
}
#############################################################################
function set_session(c: connection, message_id: int, opcode: LDAP::ProtocolOpcode) {
if (! c?$ldap ) {
c$ldap = State();
Conn::register_removal_hook(c, finalize_ldap);
}
if (! c$ldap?$messages )
c$ldap$messages = table();
if (! c$ldap?$searches )
c$ldap$searches = table();
if ((opcode in OPCODES_SEARCH) && (message_id !in c$ldap$searches)) {
c$ldap$searches[message_id] = SearchInfo($ts=network_time(),
$uid=c$uid,
$id=c$id,
$message_id=message_id,
$result_count=0);
} else if ((opcode !in OPCODES_SEARCH) && (message_id !in c$ldap$messages)) {
c$ldap$messages[message_id] = MessageInfo($ts=network_time(),
$uid=c$uid,
$id=c$id,
$message_id=message_id);
}
}
#############################################################################
event LDAP::message(c: connection,
message_id: int,
opcode: LDAP::ProtocolOpcode,
result: LDAP::ResultCode,
matched_dn: string,
diagnostic_message: string,
object: string,
argument: string) {
if (opcode == LDAP::ProtocolOpcode_SEARCH_RESULT_DONE) {
set_session(c, message_id, opcode);
local sm = c$ldap$searches[message_id];
if ( result != LDAP::ResultCode_Undef ) {
local sresult_str = RESULT_CODES[result];
if ( sm?$result && sm$result != sresult_str ) {
Reporter::conn_weird("LDAP_search_result_change", c,
fmt("%s: %s -> %s", message_id, sm$result, sresult_str), "LDAP");
}
sm$result = sresult_str;
}
if ( diagnostic_message != "" ) {
if ( sm?$diagnostic_message && sm$diagnostic_message != diagnostic_message ) {
Reporter::conn_weird("LDAP_search_diagnostic_message_change", c,
fmt("%s: %s -> %s", message_id, sm$diagnostic_message, diagnostic_message), "LDAP");
}
sm$diagnostic_message = diagnostic_message;
}
Log::write(LDAP::LDAP_SEARCH_LOG, sm);
delete c$ldap$searches[message_id];
} else if (opcode !in OPCODES_SEARCH) { # search is handled via LDAP::search_request()
set_session(c, message_id, opcode);
local m = c$ldap$messages[message_id];
local opcode_str = PROTOCOL_OPCODES[opcode];
# bind request is explicitly handled via LDAP::bind_request() and
# can assume we have a more specific m$opcode set.
if ( opcode_str != "bind" ) {
if ( m?$opcode && opcode_str != m$opcode ) {
Reporter::conn_weird("LDAP_message_opcode_change", c,
fmt("%s: %s -> %s", message_id, m$opcode, opcode_str), "LDAP");
}
m$opcode = opcode_str;
} else if ( ! m?$opcode ) {
# This can happen if we see a bind response before the bind request.
Reporter::conn_weird("LDAP_bind_without_opcode", c, fmt("%s: %s", message_id, opcode_str), "LDAP");
m$opcode = opcode_str;
}
if ( result != LDAP::ResultCode_Undef ) {
local result_str = RESULT_CODES[result];
if ( m?$result && m$result != result_str ) {
Reporter::conn_weird("LDAP_message_result_change", c,
fmt("%s: %s -> %s", message_id, m$result, result_str), "LDAP");
}
m$result = result_str;
}
if ( diagnostic_message != "" ) {
if ( m?$diagnostic_message && diagnostic_message != m$diagnostic_message ) {
Reporter::conn_weird("LDAP_message_diagnostic_message_change", c,
fmt("%s: %s -> %s", message_id, m$diagnostic_message, diagnostic_message), "LDAP");
}
m$diagnostic_message = diagnostic_message;
}
if ( object != "" ) {
if ( m?$object && m$object != object ) {
Reporter::conn_weird("LDAP_message_object_change", c,
fmt("%s: %s -> %s", message_id, m$object, object), "LDAP");
}
m$object = object;
if ( opcode == LDAP::ProtocolOpcode_EXTENDED_REQUEST )
m$object += fmt(" (%s)", EXTENDED_REQUESTS[object]);
}
if ( argument != "" ) {
if ( m$opcode == BIND_SIMPLE && ! default_capture_password )
argument = "REDACTED";
if ( m?$argument && m$argument != argument ) {
Reporter::conn_weird("LDAP_message_argument_change", c,
fmt("%s: %s -> %s", message_id, m$argument, argument), "LDAP");
}
m$argument = argument;
}
if (opcode in OPCODES_FINISHED) {
Log::write(LDAP::LDAP_LOG, m);
delete c$ldap$messages[message_id];
}
}
}
#############################################################################
event LDAP::search_request(c: connection,
message_id: int,
base_object: string,
scope: LDAP::SearchScope,
deref: LDAP::SearchDerefAlias,
size_limit: int,
time_limit: int,
types_only: bool,
filter: string,
attributes: vector of string) {
set_session(c, message_id, LDAP::ProtocolOpcode_SEARCH_REQUEST);
local sm = c$ldap$searches[message_id];
if ( scope != LDAP::SearchScope_Undef ) {
local scope_str = SEARCH_SCOPES[scope];
if ( sm?$scope && sm$scope != scope_str ) {
Reporter::conn_weird("LDAP_search_scope_change", c,
fmt("%s: %s -> %s", message_id, sm$scope, scope_str), "LDAP");
}
sm$scope = scope_str;
}
if ( deref != LDAP::SearchDerefAlias_Undef ) {
local deref_aliases_str = SEARCH_DEREF_ALIASES[deref];
if ( sm?$deref_aliases && sm$deref_aliases != deref_aliases_str ) {
Reporter::conn_weird("LDAP_search_deref_aliases_change", c,
fmt("%s: %s -> %s", message_id, sm$deref_aliases, deref_aliases_str), "LDAP");
}
sm$deref_aliases = deref_aliases_str;
}
if ( base_object != "" ) {
if ( sm?$base_object && sm$base_object != base_object ) {
Reporter::conn_weird("LDAP_search_base_object_change", c,
fmt("%s: %s -> %s", message_id, sm$base_object, base_object), "LDAP");
}
sm$base_object = base_object;
}
if ( sm?$filter && sm$filter != filter )
Reporter::conn_weird("LDAP_search_filter_change", c,
fmt("%s: %s -> %s", message_id, sm$filter, filter), "LDAP");
sm$filter = filter;
if ( default_log_search_attributes ) {
if ( sm?$attributes && cat(sm$attributes) != cat(attributes) ) {
Reporter::conn_weird("LDAP_search_attributes_change", c,
fmt("%s: %s -> %s", message_id, sm$attributes, attributes), "LDAP");
}
sm$attributes = attributes;
}
}
#############################################################################
event LDAP::search_result_entry(c: connection,
message_id: int,
object_name: string) {
set_session(c, message_id, LDAP::ProtocolOpcode_SEARCH_RESULT_ENTRY);
c$ldap$searches[message_id]$result_count += 1;
}
#############################################################################
event LDAP::bind_request(c: connection,
message_id: int,
version: int,
name: string,
authType: LDAP::BindAuthType,
authInfo: string) {
set_session(c, message_id, LDAP::ProtocolOpcode_BIND_REQUEST);
local m = c$ldap$messages[message_id];
if ( ! m?$version )
m$version = version;
# Getting herre, we don't expect the LDAP opcode to be set at all
# and it'll be overwritten below.
if ( m?$opcode )
Reporter::conn_weird("LDAP_bind_opcode_already_set", c, m$opcode, "LDAP");
switch ( authType ) {
case LDAP::BindAuthType_BIND_AUTH_SIMPLE:
m$opcode = BIND_SIMPLE;
break;
case LDAP::BindAuthType_BIND_AUTH_SASL:
m$opcode = BIND_SASL;
break;
case LDAP::BindAuthType_SICILY_NEGOTIATE:
m$opcode = BIND_SICILY_NEGOTIATE;
break;
case LDAP::BindAuthType_SICILY_RESPONSE:
m$opcode = BIND_SICILY_RESPONSE;
break;
default:
Reporter::conn_weird("LDAP_unknown_auth_type", c, cat(authType), "LDAP");
m$opcode = cat(authType);
break;
}
}
#############################################################################
hook finalize_ldap(c: connection) {
# log any "pending" unlogged LDAP messages/searches
if ( c$ldap?$messages && (|c$ldap$messages| > 0) ) {
for ( [mid], m in c$ldap$messages ) {
if (mid > 0)
Log::write(LDAP::LDAP_LOG, m);
}
delete c$ldap$messages;
}
if ( c$ldap?$searches && (|c$ldap$searches| > 0) ) {
for ( [mid], s in c$ldap$searches ) {
if (mid > 0) {
Log::write(LDAP::LDAP_SEARCH_LOG, s);
}
}
delete c$ldap$searches;
}
}