ec620a7765
* implement mdx remote * fix an unfenced code block * fix partials path Co-authored-by: Jim Kalafut <jkalafut@hashicorp.com>
114 lines
5.3 KiB
Plaintext
114 lines
5.3 KiB
Plaintext
---
|
|
layout: docs
|
|
page_title: Vault Enterprise Seal Wrap
|
|
sidebar_title: Seal Wrap / FIPS 140-2
|
|
description: |-
|
|
Vault Enterprise features a mechanism to wrap values with an extra layer of
|
|
encryption for supporting seals
|
|
---
|
|
|
|
# Seal Wrap
|
|
|
|
-> **Note**: This feature requires [Vault Enterprise](https://www.hashicorp.com/products/vault/)
|
|
with the Governance & Policy Module.
|
|
|
|
Vault Enterprise features a mechanism to wrap values with an extra layer of
|
|
encryption for supporting [seals](/docs/configuration/seal). This adds an
|
|
extra layer of protection and is useful in some compliance and regulatory
|
|
environments, including FIPS 140-2 environments.
|
|
|
|
To use this feature, you must have an active or trial license for Vault
|
|
Enterprise (HSMs) or Vault Pro (AWS KMS). To start a trial, contact [HashiCorp
|
|
sales](mailto:sales@hashicorp.com).
|
|
|
|
## Enabling/Disabling
|
|
|
|
Seal Wrap is enabled by default on supporting seals. This implies that the seal
|
|
must be available throughout Vault's runtime. Most cloud-based seals should be
|
|
quite reliable, but, for instance, if using an HSM in a non-HA setup a
|
|
connection interruption to the HSM will result in issues with Vault
|
|
functionality.
|
|
|
|
To disable seal wrapping, set `disable_sealwrap = true` in Vault's
|
|
[configuration file][configuration]. This will not affect auto-unsealing functionality; Vault's
|
|
master key will still be protected by the seal wrapping mechanism. It will
|
|
simply prevent other storage entries within Vault from being seal wrapped.
|
|
|
|
_N.B._: This is a lazy downgrade; as keys are accessed or written their seal
|
|
wrapping status will change. Similarly, if the flag is removed, it will be a
|
|
lazy upgrade (which is the case when initially upgrading to a seal
|
|
wrap-supporting version of Vault).
|
|
|
|
## FIPS 140-2 Compliance
|
|
|
|
Vault's Seal Wrap feature has been evaluated by Leidos for compliance with
|
|
FIPS 140-2 requirements. When used with a FIPS 140-2-compliant HSM, Vault will
|
|
store Critical Security Parameters (CSPs) in a manner that is compliant with
|
|
KeyStorage and KeyTransit requirements. This is on by default for many parts of
|
|
Vault and opt-in for each individual mount; see the Activating Seal Wrapping
|
|
section below for details.
|
|
|
|
[Download the current compliance letter](/docs/enterprise/sealwrap/Vault_Compliance_Letter_signed.pdf)
|
|
|
|
### Updates Since The Latest FIPS Compliance Audit
|
|
|
|
The following are values that take advantage of seal wrapping in the current
|
|
release of Vault that have not yet been asserted as compliant by Leidos. The
|
|
mechanism for seal wrapping is the same, they simply were not specifically
|
|
evaluated by the auditors.
|
|
|
|
- Root tokens
|
|
- Replication secondary activation tokens
|
|
- Client authentication information for the GCP Auth Backend
|
|
- Client authentication information for the Kubernetes Auth Backend
|
|
|
|
## Activating Seal Wrapping
|
|
|
|
For some values, seal wrapping is always enabled with a supporting seal. This
|
|
includes the recovery key, any stored key shares, the master key, the keyring,
|
|
and more; essentially, any Critical Security Parameter (CSP) within Vault's
|
|
core. If upgrading from a version of Vault that did not support seal wrapping,
|
|
the next time these values are read they will be seal-wrapped and stored.
|
|
|
|
Backend mounts within Vault can also take advantage of seal wrapping. Seal
|
|
wrapping can be activated at mount time for a given mount by mounting the
|
|
backend with the `seal_wrap` configuration value set to `true`. (This value
|
|
cannot currently be changed later.)
|
|
|
|
A given backend's author can specify which values should be seal-wrapped by
|
|
identifying where CSPs are stored. If no specific CSPs are identifiable, all
|
|
data for the backend may be seal-wrapped.
|
|
|
|
To see the current list of seal-wrapped data per backend type, see the latest
|
|
audit letter and updates in the FIPS 140-2 Compliance section above.
|
|
|
|
Note that it is often an order of magnitude or two slower to write to and read
|
|
from HSMs or remote seals. However, values will be cached in memory
|
|
un-seal-wrapped (but still encrypted by Vault's built-in cryptographic barrier)
|
|
in Vault, which will mitigate this for read-heavy workloads.
|
|
|
|
## Seal Wrap and Replication
|
|
|
|
Seal wrapping takes place below the replication logic. As a result, it is
|
|
transparent to replication. Replication will convey which values should be
|
|
seal-wrapped, but it is up to the seal on the local cluster to implement it.
|
|
In practice, this means that seal wrapping can be used without needing to have
|
|
the replicated keys on both ends of the connection; each cluster can have
|
|
distinct keys in an HSM or in KMS.
|
|
|
|
In addition, it is possible to replicate from a Shamir-protected primary
|
|
cluster to clusters that use HSMs when seal wrapping is required in downstream
|
|
datacenters but not in the primary.
|
|
|
|
Because of the level of flexibility targeted for replication, values sent over
|
|
replication connections do not currently meet KeyTransit requirements for FIPS
|
|
140-2. Vault's clustering implementation does support best practices guidance
|
|
given in FIPS 140-2, but the cryptographic implementation of TLS is not FIPS
|
|
140-2 certified. We may look into providing certified TLS in the future for
|
|
replication traffic; in the meantime, a transparent TCP proxy that supports
|
|
certified FIPS 140-2 TLS (such as
|
|
[stunnel](https://www.stunnel.org/index.html)) can be used for replication
|
|
traffic if meeting KeyTransit requirements for replication is necessary.
|
|
|
|
[configuration]: /docs/configuration
|