mirror of
https://github.com/zeek/zeek.git
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Merge branch 'master' into topic/jsiwek/autodoc-fixes
Conflicts: scripts/CMakeLists.txt scripts/base/frameworks/cluster/setup-connections.bro scripts/base/frameworks/communication/__load__.bro scripts/base/frameworks/metrics/conn-example.bro scripts/base/frameworks/metrics/http-example.bro scripts/site/local.bro
This commit is contained in:
Jon Siwek
commit
2a9ea6b8ba
96 changed files with 1809 additions and 722 deletions
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@ -214,7 +214,7 @@ event http_header(c: connection, is_orig: bool, name: string, value: string) &pr
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c$http$response_content_length = extract_count(value);
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else if ( name == "CONTENT-DISPOSITION" &&
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/[fF][iI][lL][eE][nN][aA][mM][eE]/ in value )
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c$http$filename = sub(value, /^.*[fF][iI][lL][eE][nN][aA][mM][eE]=/, "");
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c$http$filename = extract_filename_from_content_disposition(value);
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}
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}
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@ -16,11 +16,13 @@ export {
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extract_file: bool &default=F;
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## Store the file handle here for the file currently being extracted.
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extraction_file: file &optional;
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extraction_file: file &log &optional;
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};
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redef record State += {
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## Store a count of the number of files that have been transferred in
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## this conversation to create unique file names on disk.
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num_extracted_files: count &optional;
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num_extracted_files: count &default=0;
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};
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}
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@ -34,7 +36,7 @@ event mime_segment_data(c: connection, length: count, data: string) &priority=3
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{
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if ( c$mime$extract_file && c$mime$content_len == 0 )
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{
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local suffix = fmt("%d.dat", ++c$mime$num_extracted_files);
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local suffix = fmt("%d.dat", ++c$mime_state$num_extracted_files);
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local fname = generate_extraction_filename(extraction_prefix, c, suffix);
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c$mime$extraction_file = open(fname);
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enable_raw_output(c$mime$extraction_file);
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@ -1 +1,3 @@
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@load ./main
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@load ./entities
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@load ./entities-excerpt
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52
scripts/base/protocols/smtp/entities-excerpt.bro
Normal file
52
scripts/base/protocols/smtp/entities-excerpt.bro
Normal file
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@ -0,0 +1,52 @@
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##! This script is for optionally adding a body excerpt to the SMTP
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##! entities log.
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@load ./entities
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module SMTP;
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export {
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redef record SMTP::EntityInfo += {
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## The entity body excerpt.
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excerpt: string &log &default="";
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## Internal tracking to know how much of the body should be included
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## in the excerpt.
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excerpt_len: count &optional;
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};
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## This is the default value for how much of the entity body should be
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## included for all MIME entities.
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const default_entity_excerpt_len = 0 &redef;
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## This table defines how much of various entity bodies should be
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## included in excerpts.
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const entity_excerpt_len: table[string] of count = {}
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&redef
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&default = default_entity_excerpt_len;
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}
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event mime_segment_data(c: connection, length: count, data: string) &priority=-1
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{
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if ( ! c?$smtp ) return;
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if ( c$smtp$current_entity$content_len == 0 )
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c$smtp$current_entity$excerpt_len = entity_excerpt_len[c$smtp$current_entity$mime_type];
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}
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event mime_segment_data(c: connection, length: count, data: string) &priority=-2
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{
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if ( ! c?$smtp ) return;
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local ent = c$smtp$current_entity;
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if ( ent$content_len < ent$excerpt_len )
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{
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if ( ent$content_len + length < ent$excerpt_len )
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ent$excerpt = cat(ent$excerpt, data);
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else
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{
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local x_bytes = ent$excerpt_len - ent$content_len;
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ent$excerpt = cat(ent$excerpt, sub_bytes(data, 1, x_bytes));
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}
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}
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}
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234
scripts/base/protocols/smtp/entities.bro
Normal file
234
scripts/base/protocols/smtp/entities.bro
Normal file
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@ -0,0 +1,234 @@
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##! Analysis and logging for MIME entities found in SMTP sessions.
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@load base/utils/strings
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@load base/utils/files
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@load ./main
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module SMTP;
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export {
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redef enum Notice::Type += {
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## Indicates that an MD5 sum was calculated for a MIME message.
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MD5,
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};
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redef enum Log::ID += { SMTP_ENTITIES };
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type EntityInfo: record {
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## This is the timestamp of when the MIME content transfer began.
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ts: time &log;
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uid: string &log;
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id: conn_id &log;
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## Internally generated "message id" that ties back to the particular
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## message in the SMTP log where this entity was seen.
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mid: string &log;
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## The filename seen in the Content-Disposition header.
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filename: string &log &optional;
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## Track how many bytes of the MIME encoded file have been seen.
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content_len: count &log &default=0;
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## The mime type of the entity discovered through magic bytes identification.
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mime_type: string &log &optional;
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## The calculated MD5 sum for the MIME entity.
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md5: string &log &optional;
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## Optionally calculate the file's MD5 sum. Must be set prior to the
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## first data chunk being see in an event.
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calc_md5: bool &default=F;
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## This boolean value indicates if an MD5 sum is being calculated
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## for the current file transfer.
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calculating_md5: bool &default=F;
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## Optionally write the file to disk. Must be set prior to first
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## data chunk being seen in an event.
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extract_file: bool &default=F;
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## Store the file handle here for the file currently being extracted.
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extraction_file: file &log &optional;
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};
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redef record Info += {
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## The in-progress entity information.
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current_entity: EntityInfo &optional;
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};
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redef record State += {
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## Store a count of the number of files that have been transferred in
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## a conversation to create unique file names on disk.
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num_extracted_files: count &default=0;
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## Track the number of MIME encoded files transferred during a session.
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mime_level: count &default=0;
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};
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## Generate MD5 sums for these filetypes.
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const generate_md5 = /application\/x-dosexec/ # Windows and DOS executables
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| /application\/x-executable/ # *NIX executable binary
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&redef;
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## Pattern of file mime types to extract from MIME bodies.
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const extract_file_types = /NO_DEFAULT/ &redef;
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## The on-disk prefix for files to be extracted from MIME entity bodies.
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const extraction_prefix = "smtp-entity" &redef;
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global log_mime: event(rec: EntityInfo);
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}
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event bro_init() &priority=5
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{
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Log::create_stream(SMTP_ENTITIES, [$columns=EntityInfo, $ev=log_mime]);
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}
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function set_session(c: connection, new_entity: bool)
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{
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if ( ! c$smtp?$current_entity || new_entity )
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{
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local info: EntityInfo;
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info$ts=network_time();
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info$uid=c$uid;
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info$id=c$id;
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info$mid=c$smtp$mid;
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c$smtp$current_entity = info;
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++c$smtp_state$mime_level;
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}
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}
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event mime_begin_entity(c: connection) &priority=10
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{
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if ( ! c?$smtp ) return;
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set_session(c, T);
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}
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# This has priority -10 because other handlers need to know the current
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# content_len before it's updated by this handler.
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event mime_segment_data(c: connection, length: count, data: string) &priority=-10
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{
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if ( ! c?$smtp ) return;
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c$smtp$current_entity$content_len = c$smtp$current_entity$content_len + length;
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}
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event mime_segment_data(c: connection, length: count, data: string) &priority=7
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{
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if ( ! c?$smtp ) return;
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if ( c$smtp$current_entity$content_len == 0 )
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c$smtp$current_entity$mime_type = split1(identify_data(data, T), /;/)[1];
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}
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event mime_segment_data(c: connection, length: count, data: string) &priority=-5
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{
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if ( ! c?$smtp ) return;
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if ( c$smtp$current_entity$content_len == 0 )
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{
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if ( generate_md5 in c$smtp$current_entity$mime_type )
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c$smtp$current_entity$calc_md5 = T;
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if ( c$smtp$current_entity$calc_md5 )
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{
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c$smtp$current_entity$calculating_md5 = T;
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md5_hash_init(c$id);
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}
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}
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if ( c$smtp$current_entity$calculating_md5 )
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md5_hash_update(c$id, data);
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}
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## In the event of a content gap during the MIME transfer, detect the state for
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## the MD5 sum calculation and stop calculating the MD5 since it would be
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## incorrect anyway.
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event content_gap(c: connection, is_orig: bool, seq: count, length: count) &priority=5
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{
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if ( is_orig || ! c?$smtp || ! c$smtp?$current_entity ) return;
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if ( c$smtp$current_entity$calculating_md5 )
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{
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c$smtp$current_entity$calculating_md5 = F;
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md5_hash_finish(c$id);
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}
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}
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event mime_end_entity(c: connection) &priority=-3
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{
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# TODO: this check is only due to a bug in mime_end_entity that
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# causes the event to be generated twice for the same real event.
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if ( ! c?$smtp || ! c$smtp?$current_entity )
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return;
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if ( c$smtp$current_entity$calculating_md5 )
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{
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c$smtp$current_entity$md5 = md5_hash_finish(c$id);
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NOTICE([$note=MD5, $msg=fmt("Calculated a hash for a MIME entity from %s", c$id$orig_h),
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$sub=c$smtp$current_entity$md5, $conn=c]);
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}
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}
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event mime_one_header(c: connection, h: mime_header_rec)
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{
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if ( ! c?$smtp ) return;
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if ( h$name == "CONTENT-DISPOSITION" &&
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/[fF][iI][lL][eE][nN][aA][mM][eE]/ in h$value )
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c$smtp$current_entity$filename = extract_filename_from_content_disposition(h$value);
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}
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event mime_end_entity(c: connection) &priority=-5
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{
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if ( ! c?$smtp ) return;
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# This check and the delete below are just to cope with a bug where
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# mime_end_entity can be generated multiple times for the same event.
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if ( ! c$smtp?$current_entity )
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return;
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# Only log is there was some content.
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if ( c$smtp$current_entity$content_len > 0 )
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Log::write(SMTP_ENTITIES, c$smtp$current_entity);
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delete c$smtp$current_entity;
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}
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event mime_segment_data(c: connection, length: count, data: string) &priority=5
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{
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if ( ! c?$smtp ) return;
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if ( extract_file_types in c$smtp$current_entity$mime_type )
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c$smtp$current_entity$extract_file = T;
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}
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event mime_segment_data(c: connection, length: count, data: string) &priority=3
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{
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if ( ! c?$smtp ) return;
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if ( c$smtp$current_entity$extract_file &&
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c$smtp$current_entity$content_len == 0 )
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{
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local suffix = fmt("%d.dat", ++c$smtp_state$num_extracted_files);
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local fname = generate_extraction_filename(extraction_prefix, c, suffix);
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c$smtp$current_entity$extraction_file = open(fname);
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enable_raw_output(c$smtp$current_entity$extraction_file);
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}
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}
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event mime_segment_data(c: connection, length: count, data: string) &priority=-5
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{
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if ( ! c?$smtp ) return;
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if ( c$smtp$current_entity$extract_file && c$smtp$current_entity?$extraction_file )
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print c$smtp$current_entity$extraction_file, data;
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}
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event mime_end_entity(c: connection) &priority=-3
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{
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if ( ! c?$smtp ) return;
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# TODO: this check is only due to a bug in mime_end_entity that
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# causes the event to be generated twice for the same real event.
|
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if ( ! c$smtp?$current_entity )
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return;
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|
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if ( c$smtp$current_entity?$extraction_file )
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close(c$smtp$current_entity$extraction_file);
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}
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|
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@ -4,17 +4,14 @@ module SMTP;
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export {
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redef enum Log::ID += { SMTP };
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redef enum Notice::Type += {
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## Indicates that the server sent a reply mentioning an SMTP block list.
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BL_Error_Message,
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## Indicates the client's address is seen in the block list error message.
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BL_Blocked_Host,
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};
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type Info: record {
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ts: time &log;
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uid: string &log;
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id: conn_id &log;
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## This is an internally generated "message id" that can be used to
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## map between SMTP messages and MIME entities in the SMTP entities
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## log.
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mid: string &log;
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helo: string &log &optional;
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mailfrom: string &log &optional;
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rcptto: set[string] &log &optional;
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@ -30,19 +27,13 @@ export {
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second_received: string &log &optional;
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## The last message the server sent to the client.
|
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last_reply: string &log &optional;
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files: set[string] &log &optional;
|
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path: vector of addr &log &optional;
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user_agent: string &log &optional;
|
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|
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## Indicate if this session is currently transmitting SMTP message
|
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## envelope headers.
|
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in_headers: bool &default=F;
|
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## Indicate if the "Received: from" headers should still be processed.
|
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process_received_from: bool &default=T;
|
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## Maintain the current header for cases where there is header wrapping.
|
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current_header: string &default="";
|
||||
## Indicate when the message is logged and no longer applicable.
|
||||
done: bool &default=F;
|
||||
## Indicates if client activity has been seen, but not yet logged
|
||||
has_client_activity: bool &default=F;
|
||||
};
|
||||
|
||||
type State: record {
|
||||
|
|
@ -61,26 +52,7 @@ export {
|
|||
## ALL_HOSTS - always capture the entire path.
|
||||
## NO_HOSTS - never capture the path.
|
||||
const mail_path_capture = ALL_HOSTS &redef;
|
||||
|
||||
# This matches content in SMTP error messages that indicate some
|
||||
# block list doesn't like the connection/mail.
|
||||
const bl_error_messages =
|
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/spamhaus\.org\//
|
||||
| /sophos\.com\/security\//
|
||||
| /spamcop\.net\/bl/
|
||||
| /cbl\.abuseat\.org\//
|
||||
| /sorbs\.net\//
|
||||
| /bsn\.borderware\.com\//
|
||||
| /mail-abuse\.com\//
|
||||
| /b\.barracudacentral\.com\//
|
||||
| /psbl\.surriel\.com\//
|
||||
| /antispam\.imp\.ch\//
|
||||
| /dyndns\.com\/.*spam/
|
||||
| /rbl\.knology\.net\//
|
||||
| /intercept\.datapacket\.net\//
|
||||
| /uceprotect\.net\//
|
||||
| /hostkarma\.junkemailfilter\.com\// &redef;
|
||||
|
||||
|
||||
global log_smtp: event(rec: Info);
|
||||
|
||||
## Configure the default ports for SMTP analysis.
|
||||
|
|
@ -121,6 +93,7 @@ function new_smtp_log(c: connection): Info
|
|||
l$ts=network_time();
|
||||
l$uid=c$uid;
|
||||
l$id=c$id;
|
||||
l$mid=unique_id("@");
|
||||
if ( c?$smtp_state && c$smtp_state?$helo )
|
||||
l$helo = c$smtp_state$helo;
|
||||
|
||||
|
|
@ -136,26 +109,23 @@ function set_smtp_session(c: connection)
|
|||
if ( ! c?$smtp_state )
|
||||
c$smtp_state = [];
|
||||
|
||||
if ( ! c?$smtp || c$smtp$done )
|
||||
{
|
||||
if ( ! c?$smtp )
|
||||
c$smtp = new_smtp_log(c);
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
function smtp_message(c: connection)
|
||||
{
|
||||
Log::write(SMTP, c$smtp);
|
||||
|
||||
c$smtp$done = T;
|
||||
# Track the number of messages seen in this session.
|
||||
++c$smtp_state$messages_transferred;
|
||||
if ( c$smtp$has_client_activity )
|
||||
Log::write(SMTP, c$smtp);
|
||||
}
|
||||
|
||||
event smtp_request(c: connection, is_orig: bool, command: string, arg: string) &priority=5
|
||||
{
|
||||
set_smtp_session(c);
|
||||
local upper_command = to_upper(command);
|
||||
|
||||
if ( upper_command != "QUIT" )
|
||||
c$smtp$has_client_activity = T;
|
||||
|
||||
if ( upper_command == "HELO" || upper_command == "EHLO" )
|
||||
{
|
||||
|
|
@ -172,26 +142,11 @@ event smtp_request(c: connection, is_orig: bool, command: string, arg: string) &
|
|||
|
||||
else if ( upper_command == "MAIL" && /^[fF][rR][oO][mM]:/ in arg )
|
||||
{
|
||||
# In case this is not the first message in a session we want to
|
||||
# essentially write out a log, clear the session tracking, and begin
|
||||
# new session tracking.
|
||||
if ( c$smtp_state$messages_transferred > 0 )
|
||||
{
|
||||
smtp_message(c);
|
||||
set_smtp_session(c);
|
||||
}
|
||||
|
||||
local partially_done = split1(arg, /:[[:blank:]]*/)[2];
|
||||
c$smtp$mailfrom = split1(partially_done, /[[:blank:]]?/)[1];
|
||||
}
|
||||
|
||||
else if ( upper_command == "DATA" )
|
||||
{
|
||||
c$smtp$in_headers = T;
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
event smtp_reply(c: connection, is_orig: bool, code: count, cmd: string,
|
||||
msg: string, cont_resp: bool) &priority=5
|
||||
{
|
||||
|
|
@ -199,169 +154,98 @@ event smtp_reply(c: connection, is_orig: bool, code: count, cmd: string,
|
|||
|
||||
# This continually overwrites, but we want the last reply,
|
||||
# so this actually works fine.
|
||||
if ( code != 421 && code >= 400 )
|
||||
c$smtp$last_reply = fmt("%d %s", code, msg);
|
||||
}
|
||||
|
||||
event smtp_reply(c: connection, is_orig: bool, code: count, cmd: string,
|
||||
msg: string, cont_resp: bool) &priority=-5
|
||||
{
|
||||
set_smtp_session(c);
|
||||
if ( cmd == "." )
|
||||
{
|
||||
c$smtp$last_reply = fmt("%d %s", code, msg);
|
||||
|
||||
# Raise a notice when an SMTP error about a block list is discovered.
|
||||
if ( bl_error_messages in msg )
|
||||
{
|
||||
local note = BL_Error_Message;
|
||||
local message = fmt("%s received an error message mentioning an SMTP block list", c$id$orig_h);
|
||||
|
||||
# Determine if the originator's IP address is in the message.
|
||||
local ips = find_ip_addresses(msg);
|
||||
local text_ip = "";
|
||||
if ( |ips| > 0 && to_addr(ips[0]) == c$id$orig_h )
|
||||
{
|
||||
note = BL_Blocked_Host;
|
||||
message = fmt("%s is on an SMTP block list", c$id$orig_h);
|
||||
}
|
||||
|
||||
NOTICE([$note=note, $conn=c, $msg=message, $sub=msg]);
|
||||
}
|
||||
# Track the number of messages seen in this session.
|
||||
++c$smtp_state$messages_transferred;
|
||||
smtp_message(c);
|
||||
c$smtp = new_smtp_log(c);
|
||||
}
|
||||
}
|
||||
|
||||
event smtp_data(c: connection, is_orig: bool, data: string) &priority=5
|
||||
event mime_one_header(c: connection, h: mime_header_rec) &priority=5
|
||||
{
|
||||
# Is there something we should be handling from the server?
|
||||
if ( ! is_orig ) return;
|
||||
|
||||
set_smtp_session(c);
|
||||
|
||||
if ( ! c$smtp$in_headers )
|
||||
{
|
||||
if ( /^[cC][oO][nN][tT][eE][nN][tT]-[dD][iI][sS].*[fF][iI][lL][eE][nN][aA][mM][eE]/ in data )
|
||||
{
|
||||
if ( ! c$smtp?$files )
|
||||
c$smtp$files = set();
|
||||
data = sub(data, /^.*[fF][iI][lL][eE][nN][aA][mM][eE]=/, "");
|
||||
add c$smtp$files[data];
|
||||
}
|
||||
return;
|
||||
}
|
||||
if ( ! c?$smtp ) return;
|
||||
c$smtp$has_client_activity = T;
|
||||
|
||||
if ( /^[[:blank:]]*$/ in data )
|
||||
c$smtp$in_headers = F;
|
||||
if ( h$name == "MESSAGE-ID" )
|
||||
c$smtp$msg_id = h$value;
|
||||
|
||||
# This is to reconstruct headers that tend to wrap around.
|
||||
if ( /^[[:blank:]]/ in data )
|
||||
{
|
||||
# Remove all but a single space at the beginning (this seems to follow
|
||||
# the most common behavior).
|
||||
data = sub(data, /^[[:blank:]]*/, " ");
|
||||
if ( c$smtp$current_header == "MESSAGE-ID" )
|
||||
c$smtp$msg_id += data;
|
||||
else if ( c$smtp$current_header == "RECEIVED" )
|
||||
c$smtp$first_received += data;
|
||||
else if ( c$smtp$current_header == "IN-REPLY-TO" )
|
||||
c$smtp$in_reply_to += data;
|
||||
else if ( c$smtp$current_header == "SUBJECCT" )
|
||||
c$smtp$subject += data;
|
||||
else if ( c$smtp$current_header == "FROM" )
|
||||
c$smtp$from += data;
|
||||
else if ( c$smtp$current_header == "REPLY-TO" )
|
||||
c$smtp$reply_to += data;
|
||||
else if ( c$smtp$current_header == "USER-AGENT" )
|
||||
c$smtp$user_agent += data;
|
||||
return;
|
||||
}
|
||||
# Once there isn't a line starting with a blank, we're not continuing a
|
||||
# header anymore.
|
||||
c$smtp$current_header = "";
|
||||
|
||||
local header_parts = split1(data, /:[[:blank:]]*/);
|
||||
# TODO: do something in this case? This would definitely be odd.
|
||||
# Header wrapping needs to be handled more elegantly. This will happen
|
||||
# if the header value is wrapped immediately after the header key.
|
||||
if ( |header_parts| != 2 )
|
||||
return;
|
||||
|
||||
local header_key = to_upper(header_parts[1]);
|
||||
c$smtp$current_header = header_key;
|
||||
|
||||
local header_val = header_parts[2];
|
||||
|
||||
if ( header_key == "MESSAGE-ID" )
|
||||
c$smtp$msg_id = header_val;
|
||||
|
||||
else if ( header_key == "RECEIVED" )
|
||||
else if ( h$name == "RECEIVED" )
|
||||
{
|
||||
if ( c$smtp?$first_received )
|
||||
c$smtp$second_received = c$smtp$first_received;
|
||||
c$smtp$first_received = header_val;
|
||||
c$smtp$first_received = h$value;
|
||||
}
|
||||
|
||||
else if ( header_key == "IN-REPLY-TO" )
|
||||
c$smtp$in_reply_to = header_val;
|
||||
|
||||
else if ( header_key == "DATE" )
|
||||
c$smtp$date = header_val;
|
||||
|
||||
else if ( header_key == "FROM" )
|
||||
c$smtp$from = header_val;
|
||||
|
||||
else if ( header_key == "TO" )
|
||||
|
||||
else if ( h$name == "IN-REPLY-TO" )
|
||||
c$smtp$in_reply_to = h$value;
|
||||
|
||||
else if ( h$name == "SUBJECT" )
|
||||
c$smtp$subject = h$value;
|
||||
|
||||
else if ( h$name == "FROM" )
|
||||
c$smtp$from = h$value;
|
||||
|
||||
else if ( h$name == "REPLY-TO" )
|
||||
c$smtp$reply_to = h$value;
|
||||
|
||||
else if ( h$name == "DATE" )
|
||||
c$smtp$date = h$value;
|
||||
|
||||
else if ( h$name == "TO" )
|
||||
{
|
||||
if ( ! c$smtp?$to )
|
||||
c$smtp$to = set();
|
||||
add c$smtp$to[header_val];
|
||||
add c$smtp$to[h$value];
|
||||
}
|
||||
|
||||
else if ( header_key == "REPLY-TO" )
|
||||
c$smtp$reply_to = header_val;
|
||||
|
||||
else if ( header_key == "SUBJECT" )
|
||||
c$smtp$subject = header_val;
|
||||
|
||||
else if ( header_key == "X-ORIGINATING-IP" )
|
||||
else if ( h$name == "X-ORIGINATING-IP" )
|
||||
{
|
||||
local addresses = find_ip_addresses(header_val);
|
||||
local addresses = find_ip_addresses(h$value);
|
||||
if ( 1 in addresses )
|
||||
c$smtp$x_originating_ip = to_addr(addresses[1]);
|
||||
}
|
||||
|
||||
else if ( header_key == "X-MAILER" ||
|
||||
header_key == "USER-AGENT" ||
|
||||
header_key == "X-USER-AGENT" )
|
||||
{
|
||||
c$smtp$user_agent = header_val;
|
||||
# Explicitly set the current header here because there are several
|
||||
# headers bulked under this same key.
|
||||
c$smtp$current_header = "USER-AGENT";
|
||||
}
|
||||
else if ( h$name == "X-MAILER" ||
|
||||
h$name == "USER-AGENT" ||
|
||||
h$name == "X-USER-AGENT" )
|
||||
c$smtp$user_agent = h$value;
|
||||
}
|
||||
|
||||
# This event handler builds the "Received From" path by reading the
|
||||
# headers in the mail
|
||||
event smtp_data(c: connection, is_orig: bool, data: string) &priority=3
|
||||
event mime_one_header(c: connection, h: mime_header_rec) &priority=3
|
||||
{
|
||||
# If we've decided that we're done watching the received headers for
|
||||
# whatever reason, we're done. Could be due to only watching until
|
||||
# local addresses are seen in the received from headers.
|
||||
if ( c$smtp$current_header != "RECEIVED" ||
|
||||
! c$smtp$process_received_from )
|
||||
if ( ! c?$smtp || h$name != "RECEIVED" || ! c$smtp$process_received_from )
|
||||
return;
|
||||
|
||||
local text_ip = find_address_in_smtp_header(data);
|
||||
|
||||
local text_ip = find_address_in_smtp_header(h$value);
|
||||
if ( text_ip == "" )
|
||||
return;
|
||||
local ip = to_addr(text_ip);
|
||||
|
||||
|
||||
if ( ! addr_matches_host(ip, mail_path_capture) &&
|
||||
! Site::is_private_addr(ip) )
|
||||
{
|
||||
c$smtp$process_received_from = F;
|
||||
}
|
||||
|
||||
if ( c$smtp$path[|c$smtp$path|-1] != ip )
|
||||
c$smtp$path[|c$smtp$path|] = ip;
|
||||
}
|
||||
|
||||
|
||||
event connection_state_remove(c: connection) &priority=-5
|
||||
{
|
||||
if ( c?$smtp && ! c$smtp$done )
|
||||
if ( c?$smtp )
|
||||
smtp_message(c);
|
||||
}
|
||||
|
|
|
|||
|
|
@ -1,74 +1,58 @@
|
|||
##! Base SSH analysis script. The heuristic to blindly determine success or
|
||||
##! failure for SSH connections is implemented here. At this time, it only
|
||||
##! uses the size of the data being returned from the server to make the
|
||||
##! heuristic determination about success of the connection.
|
||||
##! Requires that :bro:id:`use_conn_size_analyzer` is set to T! The heuristic
|
||||
##! is not attempted if the connection size analyzer isn't enabled.
|
||||
|
||||
module SSH;
|
||||
|
||||
export {
|
||||
redef enum Log::ID += { SSH };
|
||||
|
||||
redef enum Notice::Type += {
|
||||
Login,
|
||||
Password_Guessing,
|
||||
Login_By_Password_Guesser,
|
||||
Login_From_Interesting_Hostname,
|
||||
Bytecount_Inconsistency,
|
||||
};
|
||||
|
||||
type Info: record {
|
||||
ts: time &log;
|
||||
uid: string &log;
|
||||
id: conn_id &log;
|
||||
## Indicates if the login was heuristically guessed to be "success"
|
||||
## or "failure".
|
||||
status: string &log &optional;
|
||||
direction: string &log &optional;
|
||||
remote_location: geo_location &log &optional;
|
||||
## Direction of the connection. If the client was a local host
|
||||
## logging into an external host, this would be OUTBOUD. INBOUND
|
||||
## would be set for the opposite situation.
|
||||
# TODO: handle local-local and remote-remote better.
|
||||
direction: Direction &log &optional;
|
||||
## The software string given by the client.
|
||||
client: string &log &optional;
|
||||
## The software string given by the server.
|
||||
server: string &log &optional;
|
||||
## The amount of data returned from the server. This is currently
|
||||
## the only measure of the success heuristic and it is logged to
|
||||
## assist analysts looking at the logs to make their own determination
|
||||
## about the success on a case-by-case basis.
|
||||
resp_size: count &log &default=0;
|
||||
|
||||
## Indicate if the SSH session is done being watched.
|
||||
done: bool &default=F;
|
||||
};
|
||||
|
||||
const password_guesses_limit = 30 &redef;
|
||||
|
||||
# The size in bytes at which the SSH connection is presumed to be
|
||||
# successful.
|
||||
## The size in bytes at which the SSH connection is presumed to be
|
||||
## successful.
|
||||
const authentication_data_size = 5500 &redef;
|
||||
|
||||
# The amount of time to remember presumed non-successful logins to build
|
||||
# model of a password guesser.
|
||||
const guessing_timeout = 30 mins &redef;
|
||||
|
||||
# The set of countries for which you'd like to throw notices upon successful login
|
||||
# requires Bro compiled with libGeoIP support
|
||||
const watched_countries: set[string] = {"RO"} &redef;
|
||||
|
||||
# Strange/bad host names to originate successful SSH logins
|
||||
const interesting_hostnames =
|
||||
/^d?ns[0-9]*\./ |
|
||||
/^smtp[0-9]*\./ |
|
||||
/^mail[0-9]*\./ |
|
||||
/^pop[0-9]*\./ |
|
||||
/^imap[0-9]*\./ |
|
||||
/^www[0-9]*\./ |
|
||||
/^ftp[0-9]*\./ &redef;
|
||||
|
||||
# This is a table with orig subnet as the key, and subnet as the value.
|
||||
const ignore_guessers: table[subnet] of subnet &redef;
|
||||
|
||||
# If true, we tell the event engine to not look at further data
|
||||
# packets after the initial SSH handshake. Helps with performance
|
||||
# (especially with large file transfers) but precludes some
|
||||
# kinds of analyses (e.g., tracking connection size).
|
||||
## If true, we tell the event engine to not look at further data
|
||||
## packets after the initial SSH handshake. Helps with performance
|
||||
## (especially with large file transfers) but precludes some
|
||||
## kinds of analyses (e.g., tracking connection size).
|
||||
const skip_processing_after_detection = F &redef;
|
||||
|
||||
# Keeps count of how many rejections a host has had
|
||||
global password_rejections: table[addr] of TrackCount
|
||||
&write_expire=guessing_timeout
|
||||
&synchronized;
|
||||
|
||||
# Keeps track of hosts identified as guessing passwords
|
||||
# TODO: guessing_timeout doesn't work correctly here. If a user redefs
|
||||
# the variable, it won't take effect.
|
||||
global password_guessers: set[addr] &read_expire=guessing_timeout+1hr &synchronized;
|
||||
## This event is generated when the heuristic thinks that a login
|
||||
## was successful.
|
||||
global heuristic_successful_login: event(c: connection);
|
||||
|
||||
## This event is generated when the heuristic thinks that a login
|
||||
## failed.
|
||||
global heuristic_failed_login: event(c: connection);
|
||||
|
||||
global log_ssh: event(rec: Info);
|
||||
}
|
||||
|
|
@ -106,116 +90,51 @@ function check_ssh_connection(c: connection, done: bool)
|
|||
|
||||
# If this is still a live connection and the byte count has not
|
||||
# crossed the threshold, just return and let the resheduled check happen later.
|
||||
if ( !done && c$resp$size < authentication_data_size )
|
||||
if ( !done && c$resp$num_bytes_ip < authentication_data_size )
|
||||
return;
|
||||
|
||||
# Make sure the server has sent back more than 50 bytes to filter out
|
||||
# hosts that are just port scanning. Nothing is ever logged if the server
|
||||
# doesn't send back at least 50 bytes.
|
||||
if ( c$resp$size < 50 )
|
||||
if ( c$resp$num_bytes_ip < 50 )
|
||||
return;
|
||||
|
||||
local status = "failure";
|
||||
local direction = Site::is_local_addr(c$id$orig_h) ? "to" : "from";
|
||||
local location: geo_location;
|
||||
location = (direction == "to") ? lookup_location(c$id$resp_h) : lookup_location(c$id$orig_h);
|
||||
c$ssh$direction = Site::is_local_addr(c$id$orig_h) ? OUTBOUND : INBOUND;
|
||||
c$ssh$resp_size = c$resp$num_bytes_ip;
|
||||
|
||||
if ( done && c$resp$size < authentication_data_size )
|
||||
if ( c$resp$num_bytes_ip < authentication_data_size )
|
||||
{
|
||||
# presumed failure
|
||||
if ( c$id$orig_h !in password_rejections )
|
||||
password_rejections[c$id$orig_h] = new_track_count();
|
||||
|
||||
# Track the number of rejections
|
||||
if ( !(c$id$orig_h in ignore_guessers &&
|
||||
c$id$resp_h in ignore_guessers[c$id$orig_h]) )
|
||||
++password_rejections[c$id$orig_h]$n;
|
||||
|
||||
if ( default_check_threshold(password_rejections[c$id$orig_h]) )
|
||||
{
|
||||
add password_guessers[c$id$orig_h];
|
||||
NOTICE([$note=Password_Guessing,
|
||||
$conn=c,
|
||||
$msg=fmt("SSH password guessing by %s", c$id$orig_h),
|
||||
$sub=fmt("%d failed logins", password_rejections[c$id$orig_h]$n),
|
||||
$n=password_rejections[c$id$orig_h]$n]);
|
||||
}
|
||||
}
|
||||
# TODO: This is to work around a quasi-bug in Bro which occasionally
|
||||
# causes the byte count to be oversized.
|
||||
# Watch for Gregors work that adds an actual counter of bytes transferred.
|
||||
else if ( c$resp$size < 20000000 )
|
||||
c$ssh$status = "failure";
|
||||
event SSH::heuristic_failed_login(c);
|
||||
}
|
||||
else
|
||||
{
|
||||
# presumed successful login
|
||||
status = "success";
|
||||
c$ssh$done = T;
|
||||
|
||||
if ( c$id$orig_h in password_rejections &&
|
||||
password_rejections[c$id$orig_h]$n > password_guesses_limit &&
|
||||
c$id$orig_h !in password_guessers )
|
||||
{
|
||||
add password_guessers[c$id$orig_h];
|
||||
NOTICE([$note=Login_By_Password_Guesser,
|
||||
$conn=c,
|
||||
$n=password_rejections[c$id$orig_h]$n,
|
||||
$msg=fmt("Successful SSH login by password guesser %s", c$id$orig_h),
|
||||
$sub=fmt("%d failed logins", password_rejections[c$id$orig_h]$n)]);
|
||||
}
|
||||
|
||||
local message = fmt("SSH login %s %s \"%s\" \"%s\" %f %f %s (triggered with %d bytes)",
|
||||
direction, location$country_code, location$region, location$city,
|
||||
location$latitude, location$longitude,
|
||||
id_string(c$id), c$resp$size);
|
||||
NOTICE([$note=Login,
|
||||
$conn=c,
|
||||
$msg=message,
|
||||
$sub=location$country_code]);
|
||||
|
||||
# Check to see if this login came from an interesting hostname
|
||||
when ( local hostname = lookup_addr(c$id$orig_h) )
|
||||
{
|
||||
if ( interesting_hostnames in hostname )
|
||||
{
|
||||
NOTICE([$note=Login_From_Interesting_Hostname,
|
||||
$conn=c,
|
||||
$msg=fmt("Strange login from %s", hostname),
|
||||
$sub=hostname]);
|
||||
}
|
||||
}
|
||||
|
||||
if ( location$country_code in watched_countries )
|
||||
{
|
||||
|
||||
}
|
||||
|
||||
c$ssh$status = "success";
|
||||
event SSH::heuristic_successful_login(c);
|
||||
}
|
||||
else if ( c$resp$size >= 200000000 )
|
||||
{
|
||||
NOTICE([$note=Bytecount_Inconsistency,
|
||||
$conn=c,
|
||||
$msg="During byte counting in SSH analysis, an overly large value was seen.",
|
||||
$sub=fmt("%d",c$resp$size)]);
|
||||
}
|
||||
|
||||
c$ssh$remote_location = location;
|
||||
c$ssh$status = status;
|
||||
c$ssh$direction = direction;
|
||||
c$ssh$resp_size = c$resp$size;
|
||||
|
||||
Log::write(SSH, c$ssh);
|
||||
|
||||
# Set the "done" flag to prevent the watching event from rescheduling
|
||||
# after detection is done.
|
||||
c$ssh$done;
|
||||
c$ssh$done=T;
|
||||
|
||||
# Stop watching this connection, we don't care about it anymore.
|
||||
if ( skip_processing_after_detection )
|
||||
{
|
||||
# Stop watching this connection, we don't care about it anymore.
|
||||
skip_further_processing(c$id);
|
||||
set_record_packets(c$id, F);
|
||||
}
|
||||
}
|
||||
|
||||
event SSH::heuristic_successful_login(c: connection) &priority=-5
|
||||
{
|
||||
Log::write(SSH, c$ssh);
|
||||
}
|
||||
event SSH::heuristic_failed_login(c: connection) &priority=-5
|
||||
{
|
||||
Log::write(SSH, c$ssh);
|
||||
}
|
||||
|
||||
event connection_state_remove(c: connection) &priority=-5
|
||||
{
|
||||
if ( c?$ssh )
|
||||
|
|
@ -226,7 +145,7 @@ event ssh_watcher(c: connection)
|
|||
{
|
||||
local id = c$id;
|
||||
# don't go any further if this connection is gone already!
|
||||
if ( !connection_exists(id) )
|
||||
if ( ! connection_exists(id) )
|
||||
return;
|
||||
|
||||
check_ssh_connection(c, F);
|
||||
|
|
@ -244,5 +163,9 @@ event ssh_client_version(c: connection, version: string) &priority=5
|
|||
{
|
||||
set_session(c);
|
||||
c$ssh$client = version;
|
||||
schedule +15secs { ssh_watcher(c) };
|
||||
|
||||
# The heuristic detection for SSH relies on the ConnSize analyzer.
|
||||
# Don't do the heuristics if it's disabled.
|
||||
if ( use_conn_size_analyzer )
|
||||
schedule +15secs { ssh_watcher(c) };
|
||||
}
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue