boundary/website/content/docs/configuration/kms/transit.mdx

---
layout: docs
page_title: Vault Transit - Seals - Configuration
sidebar_title: Vault Transit
description: |-
  The Transit configures Boundary to use Vault's Transit Secret Engine for key management.
---

# `transit` Seal

The Transit configures Boundary to use Vault's Transit Secret Engine for key management.

The Transit KMS is activated by the presence of a `kms "transit"` block in Boundary's configuration file

## `transit` Example

This example shows configuring Transit KMS through the Boundary configuration file
by providing all the required values:

```hcl
kms "transit" {
  address            = "https://vault:8200"
  token              = "s.Qf1s5zigZ4OX6akYjQXJC1jY"
  disable_renewal    = "false"

  // Key configuration
  key_name           = "transit_key_name"
  mount_path         = "transit/"
  namespace          = "ns1/"

  // TLS Configuration
  tls_ca_cert        = "/etc/vault/ca_cert.pem"
  tls_client_cert    = "/etc/vault/client_cert.pem"
  tls_client_key     = "/etc/vault/ca_cert.pem"
  tls_server_name    = "vault"
  tls_skip_verify    = "false"
}
```

## `transit` Parameters

These parameters apply to the `kms` stanza in the Vault configuration file:

- `address` `(string: <required>)`: The full address to the Vault cluster.
  This may also be specified by the `VAULT_ADDR` environment variable.

- `token` `(string: <required>)`: The Vault token to use. This may also be
  specified by the `VAULT_TOKEN` environment variable.

- `key_name` `(string: <required>)`: The transit key to use for encryption and
  decryption. This may also be supplied using the `VAULT_TRANSIT_SEAL_KEY_NAME`
  environment variable.

- `mount_path` `(string: <required>)`: The mount path to the transit secret engine.  
  This may also be supplied using the `VAULT_TRANSIT_SEAL_MOUNT_PATH` environment
  variable.

- `namespace` `(string: "")`: The namespace path to the transit secret engine.  
  This may also be supplied using the `VAULT_NAMESPACE` environment variable.

- `disable_renewal` `(string: "false")`: Disables the automatic renewal of the token
  in case the lifecycle of the token is managed with some other mechanism outside of
  Vault, such as Vault Agent. This may also be specified using the
  `VAULT_TRANSIT_SEAL_DISABLE_RENEWAL` environment variable.

- `tls_ca_cert` `(string: "")`: Specifies the path to the CA certificate file used
  for communication with the Vault server. This may also be specified using the
  `VAULT_CA_CERT` environment variable.

- `tls_client_cert` `(string: "")`: Specifies the path to the client certificate
  for communication with the Vault server. This may also be specified using the
  `VAULT_CLIENT_CERT` environment variable.

- `tls_client_key` `(string: "")`: Specifies the path to the private key for
  communication with the Vault server. This may also be specified using the
  `VAULT_CLIENT_KEY` environment variable.

- `tls_server_name` `(string: "")`: Name to use as the SNI host when connecting
  to the Vault server via TLS. This may also be specified via the
  `VAULT_TLS_SERVER_NAME` environment variable.

- `tls_skip_verify` `(bool: "false")`: Disable verification of TLS certificates.
  Using this option is highly discouraged and decreases the security of data
  transmissions to and from the Vault server. This may also be specified using the
  `VAULT_SKIP_VERIFY` environment variable.

## Authentication

Authentication-related values must be provided, either as environment
variables or as configuration parameters.

~> **Note:** Although the configuration file allows you to pass in
`VAULT_TOKEN` as part of the KMS's parameters, it is _strongly_ recommended
to set these values via environment variables.

The Vault token used to authenticate needs the following permissions on the
transit key:

```hcl
path "<mount path>/encrypt/<key name>" {
  capabilities = ["update"]
}

path "<mount path>/decrypt/<key name>" {
  capabilities = ["update"]
}
```