acra-poisonrecordmaker #
acra-poisonrecordmaker
is a command-line utility that generates new poison records for intrusion detection.
Command line flags #
General flags #
-
--data_length=<length>
Length of random data for data block in crypto envelope (
acrastruct
oracrablock
).Default is
-1
which is random in range 1-100. -
--type=<crypto_envelope>
Type of poison record:
acrastruct
|acrablock
.Default is
acrastruct
.
Filesystem #
-
--keys_dir=<path>
Path to keystore directory.
Default is
.acrakeys
.
TLS (available since 0.96.0) #
-
--tls_auth=<mode>
Set authentication mode that will be used for TLS connection.
0
— do not request client certificate, ignore it if received;1
— request client certificate, but don’t require it;2
— expect to receive at least one certificate to continue the handshake;3
— don’t require client certificate, but validate it if client actually sent it;4
— (default) request and validate client certificate.
These values correspond to crypto.tls.ClientAuthType.
-
--tls_key=<filename>
Path to acra-poisonrecordmaker TLS certificate’s private key of the TLS certificate presented to Database (acra-poisonrecordmaker works as “client” when communicating with Database). Empty by default.
-
--tls_cert=<filename>
Path to acra-poisonrecordmaker TLS certificate presented to Database (acra-poisonrecordmaker works as “client” when communicating with Database). Empty by default.
-
--tls_ca=<filename>
Path to acra-poisonrecordmaker TLS certificate’s CA certificate for Database certificate validation (acra-poisonrecordmaker works as “client” when communicating with Database). Empty by default.
-
--tls_crl_url=<url>
URL of the Certificate Revocation List (CRL) to use. Empty by default.
Can be either
http://
orfile://
(for local files). When using local file, Acra will simply read the file and won’t monitor filesystem for changes afterwards. Usual caching rules apply (see--tls_crl_cache_time
). -
--tls_crl_from_cert=<policy>
How to treat CRL’s URL described in a certificate itself
use
— try URL(s) from certificate after the one from configuration (if set)trust
— try first URL from certificate, if it does not contain checked certificate, stop further checksprefer
— (default) try URL(s) from certificate before the one from configuration (if set)ignore
— completely ignore CRL’s URL(s) specified in certificate
-
--tls_crl_cache_size=<count>
How many CRLs to cache in memory. Use
0
to disable caching. Maximum is1000000
. Default is16
. Cache uses LRU policy. -
--tls_crl_cache_time=<seconds>
How long to keep CRLs cached, in seconds. Use
0
to disable caching. Maximum is300
seconds. Default is0
. -
--tls_crl_check_only_leaf_certificate={true|false}
This flag controls behavior of validator in cases when certificate chain contains at least one intermediate certificate.
true
— validate only leaf certificatefalse
— (default) validate leaf certificate and all intermediate certificates
This option may be enabled in cases when intermediate CAs are trusted and there is no need to verify them all the time. Also, even if this flag is
false
but there is no CRL’s URL configured and there is no CRL’s URL in intermediate CA certificates, these intermediate CAs won’t be validated since we don’t know which CRLs could be used for validation. -
--tls_ocsp_required=<policy>
How to handle situation when OCSP server doesn’t know about requested certificate and returns “Unknown”.
denyUnknown
— (default) consider “Unknown” response an error, certificate will be rejectedallowUnknown
— reverse ofdenyUnknown
, allow certificates unknown to OCSP serverrequireGood
— require all known OCSP servers to respond “Good” in order to allow certificate and continue TLS handshake, this includes all URLs validator can use, from certificate (if not ignored) and from configuration
-
--tls_ocsp_url=<url>
URL of OCSP service. Empty by default.
Should point to HTTP server that accepts
application/ocsp-request
MIME type and responds withapplication/ocsp-response
. -
--tls_ocsp_from_cert=<policy>
How to treat OCSP server URL described in a certificate itself.
use
— try URL(s) from certificate after the one from configuration (if set)trust
— try URL(s) from certificate, if server returns “Valid”, stop further checksprefer
— (default) try URL(s) from certificate before the one from configuration (if set)ignore
— completely ignore OCSP’s URL(s) specified in certificate
-
--tls_ocsp_check_only_leaf_certificate={true|false}
This flag controls behavior of validator in cases when certificate chain contains at least one intermediate certificate.
true
— validate only leaf certificatefalse
— (default) validate leaf certificate and all intermediate certificates
This option may be enabled in cases when intermediate CAs are trusted and there is no need to verify them all the time. Also, even if this flag is
false
but there is no OCSP’s URL configured and there is no OCSP’s URL in intermediate CA certificates, these intermediate CAs won’t be validated since we don’t know whom to ask about them.
Redis #
-
--redis_db_keys=<number>
Redis database number to use. Default is
0
. -
--redis_host_port=<host:port>
Address of Redis database to use as keystore. If not specified, Redis is not used.
-
--redis_password=<password>
Password to Redis database.
Keystore #
-
--keystore_encryption_type=<strategy>
Keystore encryption strategy. Currently supported strategies:
env_master_key
(Default) - Keystore using Acra Master Key, loaded from ENV (ACRA_MASTER_KEY
) variable;vault_master_key
- Keystore using Acra Master Key, loaded from Hashicorp Vaultkms_encrypted_master_key
- Keystore using Acra Master Key, loaded from ENVACRA_MASTER_KEY
variable and decrypted via KMS key-encryption key.kms_per_client
- Keystore using KMS for decryption Acra keys per ClientID and ZoneID (zones are deprecated since 0.94.0, will be removed in 0.95.0). Create corresponded key-encryption key on KMS if not present on KMS.
KMS #
-
--kms_type=<type>
Specify your KMS. Currently supported KMS types:
aws
- AWS Key Management Service
-
--kms_credentials_path=<filepath>
A path to a file with KMS credentials JSON format.
Example of KMS config:
-
AWS:
{"access_key_id":"<access_key_id>","secret_access_key":"<secret_access_key>","region":"<region>"}
Note:
Should be provided only with --keystore_encryption_type=<kms_encrypted_master_key|kms_per_client>
flags.
Hashicorp Vault #
-
--vault_connection_api_string=<url>
Connection string (like
http://x.x.x.x:yyyy
) for loadingACRA_MASTER_KEY
from HashiCorp Vault. Default is empty (ACRA_MASTER_KEY
environment variable is expected). -
--vault_secrets_path=<path>
KV Secret Path for reading
ACRA_MASTER_KEY
from HashiCorp Vault. Default issecret/
. -
--vault_tls_transport_enable=<true|false>
Turns on/off TLS for connection with vault to
--vault_connection_api_string
endpoint.true
— turns onfalse
— (default) turns off.
-
--vault_tls_client_auth=<mode>
Set authentication mode that will be used for TLS connection with Vault.
0
— do not request client certificate, ignore it if received;1
— request client certificate, but don’t require it;2
— expect to receive at least one certificate to continue the handshake;3
— don’t require client certificate, but validate it if client actually sent it;4
— (default) request and validate client certificate.
These values correspond to crypto.tls.ClientAuthType. If not specified, acra-poisonrecordmaker uses value from
--tls_auth
flag. (since 0.96.0) -
--vault_tls_ca_path=<filename>
Path to CA certificate for HashiCorp Vault certificate validation. Default is empty (deprecated since 0.94.0, use
vault_tls_client_ca
instead). (since 0.96.0) -
--vault_tls_client_ca=<filename>
Path to acra-poisonrecordmaker TLS certificate’s CA certificate for Vault certificate validation (acra-poisonrecordmaker works as “client” when communicating with Vault). Empty by default. If not specified, acra-poisonrecordmaker uses value from
--tls_ca
flag. (since 0.96.0) -
--vault_tls_client_cert=<filename>
Path to acra-poisonrecordmaker TLS certificate presented to Vault (acra-poisonrecordmaker works as “client” when communicating with Vault). Empty by default. If not specified, acra-poisonrecordmaker uses value from
--tls_cert
flag. (since 0.96.0) -
--vault_tls_client_key=<filename>
Path to acra-poisonrecordmaker TLS certificate’s private key of the TLS certificate presented to Vault (acra-poisonrecordmaker works as “client” when communicating with Vault). Empty by default. If not specified, acra-poisonrecordmaker uses value from
--tls_key
flag. (since 0.96.0) -
--vault_tls_client_sni=<SNI>
Expected Server Name (SNI) of the Vault instance. Will be used
--vault_connection_api_string
value if is empty. Empty by default. -
--vault_tls_crl_client_cache_size=<count>
How many CRLs to cache in memory in connections to Vault. Use
0
to disable caching. Maximum is1000000
. Default is16
. Cache uses LRU policy. If not specified, acra-poisonrecordmaker uses value from--tls_crl_cache_size
flag. (since 0.96.0) -
--vault_tls_crl_client_cache_time=<seconds>
How long to keep CRLs cached, in seconds for connections to Vault. Use
0
to disable caching. Maximum is300
seconds. Default is0
. If not specified, acra-poisonrecordmaker uses value from--tls_crl_cache_time
flag. (since 0.96.0) -
--vault_tls_crl_client_check_only_leaf_certificate={true|false}
This flag controls behavior of validator in cases when Vault certificate chain contains at least one intermediate certificate.
true
— validate only leaf certificatefalse
— (default) validate leaf certificate and all intermediate certificates
This option may be enabled in cases when intermediate CAs are trusted and there is no need to verify them all the time. Also, even if this flag is
false
but there is no CRL’s URL configured and there is no CRL’s URL in intermediate CA certificates, these intermediate CAs won’t be validated since we don’t know which CRLs could be used for validation. If not specified, acra-poisonrecordmaker uses value from--tls_crl_check_only_leaf_certificate
flag. (since 0.96.0) -
--vault_tls_crl_client_from_cert=<policy>
How to treat CRL’s URL described in a certificate from Vault server/agent
use
— try URL(s) from certificate after the one from configuration (if set)trust
— try first URL from certificate, if it does not contain checked certificate, stop further checksprefer
— (default) try URL(s) from certificate before the one from configuration (if set)ignore
— completely ignore CRL’s URL(s) specified in certificate
“URL from configuration” above means the one configured with
--vault_tls_crl_client_url
flags. If not specified, acra-poisonrecordmaker uses value from--tls_crl_from_cert
flag. (since 0.96.0) -
--vault_tls_crl_client_url=<url>
CRL’s URL for outcoming TLS connections to Vault. Empty by default. If not specified, acra-poisonrecordmaker uses value from
--tls_crl_url
flag. (since 0.96.0) -
--vault_tls_ocsp_client_check_only_leaf_certificate={true|false}
This flag controls behavior of validator in cases when Vault certificate chain contains at least one intermediate certificate.
true
— validate only leaf certificatefalse
— (default) validate leaf certificate and all intermediate certificates
This option may be enabled in cases when intermediate CAs are trusted and there is no need to verify them all the time. Also, even if this flag is
false
but there is no OCSP’s URL configured and there is no OCSP’s URL in intermediate CA certificates, these intermediate CAs won’t be validated since we don’t know whom to ask about them. If not specified, acra-poisonrecordmaker uses value from--tls_ocsp_check_only_leaf_certificate
flag. (since 0.96.0) -
--vault_tls_ocsp_client_from_cert=<policy>
How to treat OCSP server URL described in a certificate from Vault server.
use
— try URL(s) from certificate after the one from configuration (if set)trust
— try URL(s) from certificate, if server returns “Valid”, stop further checksprefer
— (default) try URL(s) from certificate before the one from configuration (if set)ignore
— completely ignore OCSP’s URL(s) specified in certificate
“URL from configuration” above means the one configured with
--vault_tls_ocsp_client_url
flags. If not specified, acra-poisonrecordmaker uses value from--tls_ocsp_from_cert
flag. (since 0.96.0) -
--vault_tls_ocsp_client_required=<policy>
How to handle situation when OCSP server doesn’t know about requested Vault certificate and returns “Unknown”.
denyUnknown
— (default) consider “Unknown” response an error, certificate will be rejectedallowUnknown
— reverse ofdenyUnknown
, allow certificates unknown to OCSP serverrequireGood
— require all known OCSP servers to respond “Good” in order to allow certificate and continue TLS handshake, this includes all URLs validator can use, from certificate (if not ignored) and from configuration If not specified, acra-poisonrecordmaker uses value from--tls_ocsp_required
flag. (since 0.96.0)
-
--vault_tls_ocsp_client_url=<url>
OCSP service URL for outgoing TLS connections to check Vaults' certificates. Empty by default. If not specified, acra-poisonrecordmaker uses value from
--tls_ocsp_url
flag. (since 0.96.0)
Note:
Should be provided only with --keystore_encryption_type=<vault_master_key>
flag.
Usage #
In general, this tool is used like this:
-
Generate “poison keys” using one of
acra-poisonrecordmaker generate --keystore=vX --poison_record_keys
acra-keymaker --keystore=vX --generate_poisonrecord_keys
-
Use this tool to generate the poison record itself:
$ ./acra-poisonrecordmaker --type=acrablock > poison_record_ab $ ./acra-poisonrecordmaker --type=acrastruct > poison_record_as $ ls -l poison_record* -rw-r--r-- 1 user user 213 Nov 9 13:18 poison_record_ab -rw-r--r-- 1 user user 301 Nov 9 13:18 poison_record_as
File content will be base64-encoded:
$ cat poison_record_ab JSUlnwAAAAAAAADwIiIiIo8AAAAAAAAAAAwhAEwAAAEBQAwAAAAQAAAAIAAAAME4YnR4NYfwH6fhIoDcQsXf0GPpRPKBzE0jiPRvAx6lsbsM2wqtFXwQDP2zVB16BIL7TofIE8FEzvYK8QABAUAMAAAAEAAAAAkAAAD1FOJL82EdUoHYOEgcjk+GpWG1iEbPVZ9EyruCue7oix0Gww6D $ cat poison_record_as JSUl3wAAAAAAAADxIiIiIiIiIiJVRUMyAAAALbcKG8kCT4lmL1z3fz5JEAPknzgMbmxTqCSpirGSRi2Itmoc2pQgJwQmVAAAAAABAUAMAAAAEAAAACAAAADvLC6TB/8c3VaZoqr8nAgsw8leOB9NFwWbxoxYC5MKaXQP8RjTS7OkC9Rw3wu2ZpXCqJjN70lN4mjBq1lCAAAAAAAAAAABAUAMAAAAEAAAABYAAADzcOwIwaztpphfSKqkC6Z6l4fKIJPg39sLXFHa5qvVYvHGBAg9J4vAF9kj1RfXt6IT6w==
With usual crypto envelope header inside:
$ base64 -d poison_record_ab | hexdump -C | head -n2 00000000 25 25 25 9f 00 00 00 00 00 00 00 f0 22 22 22 22 |%%%.........""""| 00000010 8f 00 00 00 00 00 00 00 00 0c 21 00 4c 00 00 01 |..........!.L...| $ base64 -d poison_record_as | hexdump -C | head -n2 00000000 25 25 25 df 00 00 00 00 00 00 00 f1 22 22 22 22 |%%%.........""""| 00000010 22 22 22 22 55 45 43 32 00 00 00 2d b7 0a 1b c9 |""""UEC2...-....|
-
Insert generated poison record into the database or any other storage your application interacts with. It should be in the same column as the usual encrypted data (attacker won’t be able to distinguish poison records from legitimate data as they look kinda the same). Don’t forget to base64 decode before storing it in database if other encrypted data is stored in the binary format.
-
As soon as the application attempts to decrypt the poison record
- through transparent decryption in AcraServer
- or through decrypt RPC request in AcraTranslator
Acra will perform preconfigured actions.
There are two types of crypto envelopes (acrastruct
&acrablock
), and while AcraServer will simply transparently decrypt everything it can, AcraTranslator decryption methods are specific for each crypto envelope. For example, in HTTP we have/v2/decrypt
for AcraStructs and/v2/decryptSym
for AcraBlocks. This means you should use the same crypto envelope (--type
flag foracra-poisonrecordmaker
) as for other data you encrypt before storing in the database. Otherwise, you may end up catching RPC decryption errors instead of AcraTranslator catching poison record access and reacting accordingly.