File Analyzers

Files::Tag
Type:

enum

Files::ANALYZER_DATA_EVENT
Files::ANALYZER_ENTROPY
Files::ANALYZER_EXTRACT
Files::ANALYZER_MD5
Files::ANALYZER_SHA1
Files::ANALYZER_SHA256
Files::ANALYZER_PE
Files::ANALYZER_UNIFIED2
Files::ANALYZER_OCSP_REPLY
Files::ANALYZER_OCSP_REQUEST
Files::ANALYZER_X509

Bro::FileDataEvent

Delivers file content

Bro::FileEntropy

Entropy test file content

Events

file_entropy
Type:event (f: fa_file, ent: entropy_test_result)

This event is generated each time file analysis performs entropy testing on a file.

F:The file.
Ent:The results of the entropy testing.

Bro::FileExtract

Extract file content

Events

file_extraction_limit
Type:event (f: fa_file, args: Files::AnalyzerArgs, limit: count, len: count)

This event is generated when a file extraction analyzer is about to exceed the maximum permitted file size allowed by the extract_limit field of Files::AnalyzerArgs. The analyzer is automatically removed from file f.

F:The file.
Args:Arguments that identify a particular file extraction analyzer. This is only provided to be able to pass along to FileExtract::set_limit.
Limit:The limit, in bytes, the extracted file is about to breach.
Len:The length of the file chunk about to be written.

See also: Files::add_analyzer, Files::ANALYZER_EXTRACT

Functions

FileExtract::__set_limit
Type:function (file_id: string, args: any, n: count) : bool

FileExtract::set_limit.

Bro::FileHash

Hash file content

Events

file_hash
Type:event (f: fa_file, kind: string, hash: string)

This event is generated each time file analysis generates a digest of the file contents.

F:The file.
Kind:The type of digest algorithm.
Hash:The result of the hashing.

See also: Files::add_analyzer, Files::ANALYZER_MD5, Files::ANALYZER_SHA1, Files::ANALYZER_SHA256

Bro::PE

Portable Executable analyzer

Events

pe_dos_header
Type:event (f: fa_file, h: PE::DOSHeader)

A PE file DOS header was parsed. This is the top-level header and contains information like the size of the file, initial value of registers, etc.

F:The file.
H:The parsed DOS header information.

See also: pe_dos_code, pe_file_header, pe_optional_header, pe_section_header

pe_dos_code
Type:event (f: fa_file, code: string)

A PE file DOS stub was parsed. The stub is a valid application that runs under MS-DOS, by default to inform the user that the program can’t be run in DOS mode.

F:The file.
Code:The DOS stub

See also: pe_dos_header, pe_file_header, pe_optional_header, pe_section_header

pe_file_header
Type:event (f: fa_file, h: PE::FileHeader)

A PE file file header was parsed. This header contains information like the target machine, the timestamp when the file was created, the number of sections, and pointers to other parts of the file.

F:The file.
H:The parsed file header information.

See also: pe_dos_header, pe_dos_code, pe_optional_header, pe_section_header

pe_optional_header
Type:event (f: fa_file, h: PE::OptionalHeader)

A PE file optional header was parsed. This header is required for executable files, but not for object files. It contains information like OS requirements to execute the file, the original entry point address, and information needed to load the file into memory.

F:The file.
H:The parsed optional header information.

See also: pe_dos_header, pe_dos_code, pe_file_header, pe_section_header

pe_section_header
Type:event (f: fa_file, h: PE::SectionHeader)

A PE file section header was parsed. This header contains information like the section name, size, address, and characteristics.

F:The file.
H:The parsed section header information.

See also: pe_dos_header, pe_dos_code, pe_file_header, pe_optional_header

Bro::Unified2

Analyze Unified2 alert files.

Types

Unified2::IDSEvent
Type:

record

sensor_id: count

event_id: count

ts: time

signature_id: count

generator_id: count

signature_revision: count

classification_id: count

priority_id: count

src_ip: addr

dst_ip: addr

src_p: port

dst_p: port

impact_flag: count

impact: count

blocked: count

mpls_label: count &optional

Not available in “legacy” IDS events.

vlan_id: count &optional

Not available in “legacy” IDS events.

packet_action: count &optional

Only available in “legacy” IDS events.
Unified2::Packet
Type:

record

sensor_id: count

event_id: count

event_second: count

packet_ts: time

link_type: count

data: string

Events

unified2_event
Type:event (f: fa_file, ev: Unified2::IDSEvent)

Abstract all of the various Unified2 event formats into a single event.

F:The file.
Ev:TODO.
unified2_packet
Type:event (f: fa_file, pkt: Unified2::Packet)

The Unified2 packet format event.

F:The file.
Pkt:TODO.

Bro::X509

X509 and OCSP analyzer

Types

X509::Certificate
Type:

record

version: count &log

Version number.

serial: string &log

Serial number.

subject: string &log

Subject.

issuer: string &log

Issuer.

cn: string &optional

Last (most specific) common name.

not_valid_before: time &log

Timestamp before when certificate is not valid.

not_valid_after: time &log

Timestamp after when certificate is not valid.

key_alg: string &log

Name of the key algorithm

sig_alg: string &log

Name of the signature algorithm

key_type: string &optional &log

Key type, if key parseable by openssl (either rsa, dsa or ec)

key_length: count &optional &log

Key length in bits

exponent: string &optional &log

Exponent, if RSA-certificate

curve: string &optional &log

Curve, if EC-certificate
X509::Extension
Type:

record

name: string

Long name of extension. oid if name not known

short_name: string &optional

Short name of extension if known

oid: string

Oid of extension

critical: bool

True if extension is critical

value: string

Extension content parsed to string for known extensions. Raw data otherwise.
X509::BasicConstraints
Type:

record

ca: bool &log

CA flag set?

path_len: count &optional &log

Maximum path length
Attributes:

&log
X509::SubjectAlternativeName
Type:

record

dns: string_vec &optional &log

List of DNS entries in SAN

uri: string_vec &optional &log

List of URI entries in SAN

email: string_vec &optional &log

List of email entries in SAN

ip: addr_vec &optional &log

List of IP entries in SAN

other_fields: bool

True if the certificate contained other, not recognized or parsed name fields
X509::Result
Type:

record

result: int

OpenSSL result code

result_string: string

Result as string

chain_certs: vector of opaque of x509 &optional

References to the final certificate chain, if verification successful. End-host certificate is first.

Result of an X509 certificate chain verification

Events

x509_certificate
Type:event (f: fa_file, cert_ref: opaque of x509, cert: X509::Certificate)

Generated for encountered X509 certificates, e.g., in the clear SSL/TLS connection handshake.

See Wikipedia for more information about the X.509 format.

F:The file.
Cert_ref:An opaque pointer to the underlying OpenSSL data structure of the certificate.
Cert:The parsed certificate information.

See also: x509_extension, x509_ext_basic_constraints, x509_ext_subject_alternative_name, x509_parse, x509_verify, x509_get_certificate_string, x509_ocsp_ext_signed_certificate_timestamp

x509_extension
Type:event (f: fa_file, ext: X509::Extension)

Generated for X509 extensions seen in a certificate.

See Wikipedia for more information about the X.509 format.

F:The file.
Ext:The parsed extension.

See also: x509_certificate, x509_ext_basic_constraints, x509_ext_subject_alternative_name, x509_parse, x509_verify, x509_get_certificate_string, x509_ocsp_ext_signed_certificate_timestamp

x509_ext_basic_constraints
Type:event (f: fa_file, ext: X509::BasicConstraints)

Generated for the X509 basic constraints extension seen in a certificate. This extension can be used to identify the subject of a certificate as a CA.

F:The file.
Ext:The parsed basic constraints extension.

See also: x509_certificate, x509_extension, x509_ext_subject_alternative_name, x509_parse, x509_verify, x509_get_certificate_string, x509_ocsp_ext_signed_certificate_timestamp

x509_ext_subject_alternative_name
Type:event (f: fa_file, ext: X509::SubjectAlternativeName)

Generated for the X509 subject alternative name extension seen in a certificate. This extension can be used to allow additional entities to be bound to the subject of the certificate. Usually it is used to specify one or multiple DNS names for which a certificate is valid.

F:The file.
Ext:The parsed subject alternative name extension.

See also: x509_certificate, x509_extension, x509_ext_basic_constraints, x509_parse, x509_verify, x509_ocsp_ext_signed_certificate_timestamp, x509_get_certificate_string

x509_ocsp_ext_signed_certificate_timestamp
Type:event (f: fa_file, version: count, logid: string, timestamp: count, hash_algorithm: count, signature_algorithm: count, signature: string)

Generated for the signed_certificate_timestamp X509 extension as defined in RFC 6962. The extension is used to transmit signed proofs that are used for Certificate Transparency. Raised when the extension is encountered in an X.509 certificate or in an OCSP reply.

F:The file.
Version:the version of the protocol to which the SCT conforms. Always should be 0 (representing version 1)
Logid:32 bit key id
Timestamp:the NTP Time when the entry was logged measured since the epoch, ignoring leap seconds, in milliseconds.
Signature_and_hashalgorithm:
 signature and hash algorithm used for the digitally_signed struct
Signature:signature part of the digitally_signed struct

See also: ssl_extension_signed_certificate_timestamp, x509_extension, x509_ext_basic_constraints, x509_parse, x509_verify, x509_ext_subject_alternative_name, x509_get_certificate_string ssl_extension_signed_certificate_timestamp, sct_verify, ocsp_request, ocsp_request_certificate, ocsp_response_status, ocsp_response_bytes, ocsp_response_certificate, x509_ocsp_ext_signed_certificate_timestamp

ocsp_request
Type:event (f: fa_file, version: count)

Event that is raised when encountering an OCSP request, e.g. in an HTTP connection. See RFC 6960 for more details.

This event is raised exactly once for each OCSP Request.

F:The file.
Req:version: the version of the OCSP request. Typically 0 (Version 1).

See also: ocsp_request_certificate, ocsp_response_status, ocsp_response_bytes, ocsp_response_certificate, ocsp_extension, x509_ocsp_ext_signed_certificate_timestamp

ocsp_request_certificate
Type:event (f: fa_file, hashAlgorithm: string, issuerNameHash: string, issuerKeyHash: string, serialNumber: string)

Event that is raised when encountering an OCSP request for a certificate, e.g. in an HTTP connection. See RFC 6960 for more details.

Note that a single OCSP request can contain requests for several certificates. Thus this event can fire several times for one OCSP request, each time requesting information for a different (or in theory even the same) certificate.

F:The file.
HashAlgorithm:The hash algorithm used for the issuerKeyHash.
IssuerKeyHash:Hash of the issuers public key.
SerialNumber:Serial number of the certificate for which the status is requested.

See also: ocsp_request, ocsp_response_status, ocsp_response_bytes, ocsp_response_certificate, ocsp_extension, x509_ocsp_ext_signed_certificate_timestamp

ocsp_response_status
Type:event (f: fa_file, status: string)

This event is raised when encountering an OCSP reply, e.g. in an HTTP connection or a TLS extension. See RFC 6960 for more details.

This event is raised exactly once for each OCSP reply.

F:The file.
Status:The status of the OCSP response (e.g. succesful, malformedRequest, tryLater).

See also: ocsp_request, ocsp_request_certificate, ocsp_response_bytes, ocsp_response_certificate, ocsp_extension, x509_ocsp_ext_signed_certificate_timestamp

ocsp_response_bytes
Type:event (f: fa_file, resp_ref: opaque of ocsp_resp, status: string, version: count, responderId: string, producedAt: time, signatureAlgorithm: string, certs: x509_opaque_vector)

This event is raised when encountering an OCSP response that contains response information. An OCSP reply can be encountered, for example, in an HTTP connection or a TLS extension. See RFC 6960 for more details on OCSP.

F:The file.
Req_ref:An opaque pointer to the underlying OpenSSL data structure of the OCSP response.
Status:The status of the OCSP response (e.g. succesful, malformedRequest, tryLater).
Version:Version of the OCSP response (typically - for version 1).
ResponderId:The id of the OCSP responder; either a public key hash or a distinguished name.
ProducedAt:Time at which the reply was produced.
SignatureAlgorithm:
 Algorithm used for the OCSP signature.
Certs:Optional list of certificates that are sent with the OCSP response; these typically are needed to perform validation of the reply.

See also: ocsp_request, ocsp_request_certificate, ocsp_response_status, ocsp_response_certificate, ocsp_extension, x509_ocsp_ext_signed_certificate_timestamp

ocsp_response_certificate
Type:event (f: fa_file, hashAlgorithm: string, issuerNameHash: string, issuerKeyHash: string, serialNumber: string, certStatus: string, revokeTime: time, revokeReason: string, thisUpdate: time, nextUpdate: time)

This event is raised for each SingleResponse contained in an OCSP response. See RFC 6960 for more details on OCSP.

F:The file.
HashAlgorithm:The hash algorithm used for issuerNameHash and issuerKeyHash.
IssuerNameHash:Hash of the issuer’s distinguished name.
IssuerKeyHash:Hash of the issuer’s public key.
SerialNumber:Serial number of the affected certificate.
CertStatus:Status of the certificate.
RevokeTime:Time the certificate was revoked, 0 if not revoked.
RevokeTeason:Reason certificate was revoked; empty string if not revoked or not specified.
ThisUpdate:Time this response was generated.
NextUpdate:Time next response will be ready; 0 if not supploed.

See also: ocsp_request, ocsp_request_certificate, ocsp_response_status, ocsp_response_bytes, ocsp_extension, x509_ocsp_ext_signed_certificate_timestamp

ocsp_extension
Type:event (f: fa_file, ext: X509::Extension, global_resp: bool)

This event is raised when an OCSP extension is encountered in an OCSP response. See RFC 6960 for more details on OCSP.

F:The file.
Ext:The parsed extension (same format as X.509 extensions).
Global_resp:T if extension encountered in the global response (in ResponseData), F when encountered in a SingleResponse.

See also: ocsp_request, ocsp_request_certificate, ocsp_response_status, ocsp_response_bytes, ocsp_response_certificate, x509_ocsp_ext_signed_certificate_timestamp

Functions

x509_parse
Type:function (cert: opaque of x509) : X509::Certificate

Parses a certificate into an X509::Certificate structure.

Cert:The X509 certificate opaque handle.
Returns:A X509::Certificate structure.

See also: x509_certificate, x509_extension, x509_ext_basic_constraints, x509_ext_subject_alternative_name, x509_verify, x509_get_certificate_string

x509_get_certificate_string
Type:function (cert: opaque of x509, pem: bool &default = F &optional) : string

Returns the string form of a certificate.

Cert:The X509 certificate opaque handle.
Pem:A boolean that specifies if the certificate is returned in pem-form (true), or as the raw ASN1 encoded binary (false).
Returns:X509 certificate as a string.

See also: x509_certificate, x509_extension, x509_ext_basic_constraints, x509_ext_subject_alternative_name, x509_parse, x509_verify

x509_ocsp_verify
Type:function (certs: x509_opaque_vector, ocsp_reply: string, root_certs: table_string_of_string, verify_time: time &default = 0.0 &optional) : X509::Result

Verifies an OCSP reply.

Certs:Specifies the certificate chain to use. Server certificate first.
Ocsp_reply:the ocsp reply to validate.
Root_certs:A list of root certificates to validate the certificate chain.
Verify_time:Time for the validity check of the certificates.
Returns:A record of type X509::Result containing the result code of the verify operation.

See also: x509_certificate, x509_extension, x509_ext_basic_constraints, x509_ext_subject_alternative_name, x509_parse, x509_get_certificate_string, x509_verify

x509_verify
Type:function (certs: x509_opaque_vector, root_certs: table_string_of_string, verify_time: time &default = 0.0 &optional) : X509::Result

Verifies a certificate.

Certs:Specifies a certificate chain that is being used to validate the given certificate against the root store given in root_certs. The host certificate has to be at index 0.
Root_certs:A list of root certificates to validate the certificate chain.
Verify_time:Time for the validity check of the certificates.
Returns:A record of type X509::Result containing the result code of the verify operation. In case of success also returns the full certificate chain.

See also: x509_certificate, x509_extension, x509_ext_basic_constraints, x509_ext_subject_alternative_name, x509_parse, x509_get_certificate_string, x509_ocsp_verify, sct_verify

sct_verify
Type:function (cert: opaque of x509, logid: string, log_key: string, signature: string, timestamp: count, hash_algorithm: count, issuer_key_hash: string &default = "" &optional) : bool

Verifies a Signed Certificate Timestamp as used for Certificate Transparency. See RFC6962 for more details.

Cert:Certificate against which the SCT should be validated.
Logid:Log id of the SCT.
Log_key:Public key of the Log that issued the SCT proof.
Timestamp:Timestamp at which the proof was generated.
Hash_algorithm:Hash algorithm that was used for the SCT proof.
Issuer_key_hash:
 The SHA-256 hash of the certificate issuer’s public key. This only has to be provided if the SCT was encountered in an X.509 certificate extension; in that case, it is necessary for validation.
Returns:T if the validation could be performed succesfully, F otherwhise.

See also: ssl_extension_signed_certificate_timestamp, x509_ocsp_ext_signed_certificate_timestamp, x509_verify

x509_subject_name_hash
Type:function (cert: opaque of x509, hash_alg: count) : string

Get the hash of the subject’s distinguished name.

Cert:

The X509 certificate opaque handle.
Hash_alg:

the hash algorithm to use, according to the IANA mapping at

:https://www.iana.org/assignments/tls-parameters/tls-parameters.xhtml#tls-parameters-18
Returns:

The hash as a string.

See also: x509_issuer_name_hash, x509_spki_hash, x509_verify, sct_verify

x509_issuer_name_hash
Type:function (cert: opaque of x509, hash_alg: count) : string

Get the hash of the issuer’s distinguished name.

Cert:

The X509 certificate opaque handle.
Hash_alg:

the hash algorithm to use, according to the IANA mapping at

:https://www.iana.org/assignments/tls-parameters/tls-parameters.xhtml#tls-parameters-18
Returns:

The hash as a string.

See also: x509_subject_name_hash, x509_spki_hash, x509_verify, sct_verify

x509_spki_hash
Type:function (cert: opaque of x509, hash_alg: count) : string

Get the hash of the Subject Public Key Information of the certificate.

Cert:

The X509 certificate opaque handle.
Hash_alg:

the hash algorithm to use, according to the IANA mapping at

:https://www.iana.org/assignments/tls-parameters/tls-parameters.xhtml#tls-parameters-18
Returns:

The hash as a string.

See also: x509_subject_name_hash, x509_issuer_name_hash, x509_verify, sct_verify


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Copyright 2016, The Bro Project. Last updated on January 10, 2019. Created using Sphinx 1.7.5.