cipheredit

This is a community-maintained plugin! It does not ship with Logstash by default, but it is easy to install by running bin/plugin install logstash-filter-cipher.

This filter parses a source and apply a cipher or decipher before storing it in the target.

 

Synopsisedit

This plugin supports the following configuration options:

Required configuration options:

cipher {
    algorithm => ...
    mode => ...
}

Available configuration options:

Setting Input type Required Default value

add_field

hash

No

{}

add_tag

array

No

[]

algorithm

string

Yes

base64

boolean

No

true

cipher_padding

string

No

iv

string

No

key

string

No

key_pad

<<,>>

No

"\u0000"

key_size

number

No

32

mode

string

Yes

periodic_flush

boolean

No

false

remove_field

array

No

[]

remove_tag

array

No

[]

source

string

No

"message"

target

string

No

"message"

Detailsedit

 

add_fieldedit

  • Value type is hash
  • Default value is {}

If this filter is successful, add any arbitrary fields to this event. Field names can be dynamic and include parts of the event using the %{field}.

Example:

    filter {
      cipher {
        add_field => { "foo_%{somefield}" => "Hello world, from %{host}" }
      }
    }
[source,ruby]
    # You can also add multiple fields at once:
    filter {
      cipher {
        add_field => {
          "foo_%{somefield}" => "Hello world, from %{host}"
          "new_field" => "new_static_value"
        }
      }
    }

If the event has field "somefield" == "hello" this filter, on success, would add field foo_hello if it is present, with the value above and the %{host} piece replaced with that value from the event. The second example would also add a hardcoded field.

add_tagedit

  • Value type is array
  • Default value is []

If this filter is successful, add arbitrary tags to the event. Tags can be dynamic and include parts of the event using the %{field} syntax.

Example:

    filter {
      cipher {
        add_tag => [ "foo_%{somefield}" ]
      }
    }
[source,ruby]
    # You can also add multiple tags at once:
    filter {
      cipher {
        add_tag => [ "foo_%{somefield}", "taggedy_tag"]
      }
    }

If the event has field "somefield" == "hello" this filter, on success, would add a tag foo_hello (and the second example would of course add a taggedy_tag tag).

algorithmedit

  • This is a required setting.
  • Value type is string
  • There is no default value for this setting.

The cipher algorythm

A list of supported algorithms can be obtained by

    puts OpenSSL::Cipher.ciphers

base64edit

  • Value type is boolean
  • Default value is true

Do we have to perform a base64 decode or encode?

If we are decrypting, base64 decode will be done before. If we are encrypting, base64 will be done after.

cipher_paddingedit

  • Value type is string
  • There is no default value for this setting.

Cypher padding to use. Enables or disables padding.

By default encryption operations are padded using standard block padding and the padding is checked and removed when decrypting. If the pad parameter is zero then no padding is performed, the total amount of data encrypted or decrypted must then be a multiple of the block size or an error will occur.

See EVP_CIPHER_CTX_set_padding for further information.

We are using Openssl jRuby which uses default padding to PKCS5Padding If you want to change it, set this parameter. If you want to disable it, Set this parameter to 0

    filter { cipher { padding => 0 }}

exclude_tags (DEPRECATED)edit

  • DEPRECATED WARNING: This configuration item is deprecated and may not be available in future versions.
  • Value type is array
  • Default value is []

Only handle events without any of these tags. Optional.

ivedit

  • Value type is string
  • There is no default value for this setting.

The initialization vector to use

The cipher modes CBC, CFB, OFB and CTR all need an "initialization vector", or short, IV. ECB mode is the only mode that does not require an IV, but there is almost no legitimate use case for this mode because of the fact that it does not sufficiently hide plaintext patterns.

keyedit

  • Value type is string
  • There is no default value for this setting.

The key to use

key_padedit

<li> Value type is <<string,string>>
* Default value is `"\u0000"`

The character used to pad the key

key_sizeedit

  • Value type is number
  • Default value is 32

The key size to pad

It depends of the cipher algorythm.I your key don’t need padding, don’t set this parameter

Example, for AES-256, we must have 32 char long key

    filter { cipher { key_size => 32 }

modeedit

  • This is a required setting.
  • Value type is string
  • There is no default value for this setting.

Encrypting or decrypting some data

Valid values are encrypt or decrypt

periodic_flushedit

  • Value type is boolean
  • Default value is false

Call the filter flush method at regular interval. Optional.

remove_fieldedit

  • Value type is array
  • Default value is []

If this filter is successful, remove arbitrary fields from this event. Fields names can be dynamic and include parts of the event using the %{field} Example:

    filter {
      cipher {
        remove_field => [ "foo_%{somefield}" ]
      }
    }
[source,ruby]
    # You can also remove multiple fields at once:
    filter {
      cipher {
        remove_field => [ "foo_%{somefield}", "my_extraneous_field" ]
      }
    }

If the event has field "somefield" == "hello" this filter, on success, would remove the field with name foo_hello if it is present. The second example would remove an additional, non-dynamic field.

remove_tagedit

  • Value type is array
  • Default value is []

If this filter is successful, remove arbitrary tags from the event. Tags can be dynamic and include parts of the event using the %{field} syntax.

Example:

    filter {
      cipher {
        remove_tag => [ "foo_%{somefield}" ]
      }
    }
[source,ruby]
    # You can also remove multiple tags at once:
    filter {
      cipher {
        remove_tag => [ "foo_%{somefield}", "sad_unwanted_tag"]
      }
    }

If the event has field "somefield" == "hello" this filter, on success, would remove the tag foo_hello if it is present. The second example would remove a sad, unwanted tag as well.

sourceedit

  • Value type is string
  • Default value is "message"

The field to perform filter

Example, to use the @message field (default) :

    filter { cipher { source => "message" } }

tags (DEPRECATED)edit

  • DEPRECATED WARNING: This configuration item is deprecated and may not be available in future versions.
  • Value type is array
  • Default value is []

Only handle events with all of these tags. Optional.

targetedit

  • Value type is string
  • Default value is "message"

The name of the container to put the result

Example, to place the result into crypt :

    filter { cipher { target => "crypt" } }

type (DEPRECATED)edit

  • DEPRECATED WARNING: This configuration item is deprecated and may not be available in future versions.
  • Value type is string
  • Default value is ""

Note that all of the specified routing options (type,tags,exclude_tags,include_fields, exclude_fields) must be met in order for the event to be handled by the filter. The type to act on. If a type is given, then this filter will only act on messages with the same type. See any input plugin’s type attribute for more. Optional.