zeek/scripts/policy/frameworks/intel/seen/smtp.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

104 lines
2.6 KiB
Text

@load base/utils/email
@load base/frameworks/intel
@load base/protocols/smtp
@load ./where-locations
event mime_end_entity(c: connection) &group="Intel::ADDR"
{
if ( c?$smtp )
{
if ( c$smtp?$path )
{
local path = c$smtp$path;
for ( i in path )
{
Intel::seen(Intel::Seen($host=path[i],
$conn=c,
$where=SMTP::IN_RECEIVED_HEADER));
}
}
if ( c$smtp?$x_originating_ip )
Intel::seen(Intel::Seen($host=c$smtp$x_originating_ip,
$conn=c,
$where=SMTP::IN_X_ORIGINATING_IP_HEADER));
}
}
event mime_end_entity(c: connection) &group="Intel::SOFTWARE"
{
if ( c?$smtp )
{
if ( c$smtp?$user_agent )
Intel::seen(Intel::Seen($indicator=c$smtp$user_agent,
$indicator_type=Intel::SOFTWARE,
$conn=c,
$where=SMTP::IN_HEADER));
}
}
event mime_end_entity(c: connection) &group="Intel::EMAIL"
{
if ( c?$smtp )
{
if ( c$smtp?$mailfrom )
{
Intel::seen(Intel::Seen($indicator=c$smtp$mailfrom,
$indicator_type=Intel::EMAIL,
$conn=c,
$where=SMTP::IN_MAIL_FROM ));
}
if ( c$smtp?$rcptto )
{
for ( rcptto_addr in c$smtp$rcptto )
{
Intel::seen(Intel::Seen($indicator=rcptto_addr,
$indicator_type=Intel::EMAIL,
$conn=c,
$where=SMTP::IN_RCPT_TO));
}
}
if ( c$smtp?$from )
{
for ( from_addr in extract_email_addrs_set(c$smtp$from) )
{
Intel::seen(Intel::Seen($indicator=from_addr,
$indicator_type=Intel::EMAIL,
$conn=c,
$where=SMTP::IN_FROM));
}
}
if ( c$smtp?$to )
{
for ( email_to_addr in c$smtp$to )
{
Intel::seen(Intel::Seen($indicator=extract_first_email_addr(email_to_addr),
$indicator_type=Intel::EMAIL,
$conn=c,
$where=SMTP::IN_TO));
}
}
if ( c$smtp?$cc )
{
for ( cc_addr in c$smtp$cc )
{
Intel::seen(Intel::Seen($indicator=cc_addr,
$indicator_type=Intel::EMAIL,
$conn=c,
$where=SMTP::IN_CC));
}
}
if ( c$smtp?$reply_to )
{
Intel::seen(Intel::Seen($indicator=c$smtp$reply_to,
$indicator_type=Intel::EMAIL,
$conn=c,
$where=SMTP::IN_REPLY_TO));
}
}
}