Permalink
Find file
834 lines (680 sloc) 26.4 KB

Spring Cloud Vault

© 2016 The original authors.

Note
Copies of this document may be made for your own use and for distribution to others, provided that you do not charge any fee for such copies and further provided that each copy contains this Copyright Notice, whether distributed in print or electronically.

Quick Start

Authentication methods

Different organizations have different requirements for security and authentication. Vault reflects that need by shipping multiple authentication methods. Spring Cloud Vault supports token and AppId authentication.

Token authentication

Tokens are the core method for authentication within Vault. Token authentication requires a static token to be provided using the Bootstrap Application Context.

Note
Token authentication is the default authentication method. If a token is disclosed an unintended party gains access to Vault and can access secrets for the intended client.
Example 1. bootstrap.yml
spring.cloud.vault:
    authentication: TOKEN
    token: 00000000-0000-0000-0000-000000000000
  • authentication setting this value to TOKEN selects the Token authentication method

  • token sets the static token to use

AppId authentication

Vault supports AppId authentication that consists of two hard to guess tokens. The AppId defaults to spring.application.name that is statically configured. The second token is the UserId which is a part determined by the application, usually related to the runtime environment. IP address, Mac address or a Docker container name are good examples. Spring Cloud Vault Config supports IP address, Mac address and static UserId’s (e.g. supplied via System properties). The IP and Mac address are represented as Hex-encoded SHA256 hash.

IP address-based UserId’s use the local host’s IP address.

Example 2. bootstrap.yml using SHA256 IP-Address UserId’s
spring.cloud.vault:
    authentication: APPID
    app-id:
        user-id: IP_ADDRESS
  • authentication setting this value to APPID selects the AppId authentication method

  • app-id-path sets the path of the AppId mount to use

  • user-id sets the UserId method. Possible values are IP_ADDRESS, MAC_ADDRESS or a class name implementing a custom AppIdUserIdMechanism

The corresponding command to generate the IP address UserId from a command line is:

$ echo -n 192.168.99.1 | sha256sum
Note
Including the line break of echo leads to a different hash value so make sure to include the -n flag.

Mac address-based UserId’s obtain their network device from the localhost-bound device. The configuration also allows specifying a network-interface hint to pick the right device. The value of network-interface is optional and can be either an interface name or interface index (0-based).

Example 3. bootstrap.yml using SHA256 Mac-Address UserId’s
spring.cloud.vault:
    authentication: APPID
    app-id:
        user-id: MAC_ADDRESS
        network-interface: eth0
  • network-interface sets network interface to obtain the physical address

The corresponding command to generate the IP address UserId from a command line is:

$ echo -n 0AFEDE1234AC | sha256sum
Note
The Mac address is specified uppercase and without colons. Including the line break of echo leads to a different hash value so make sure to include the -n flag.

Custom UserId

The UserId generation is an open mechanism. You can set spring.cloud.vault.app-id.user-id to any string and the configured value will be used as static UserId.

A more advanced approach lets you set spring.cloud.vault.app-id.user-id to a classname. This class must be on your classpath and must implement the org.springframework.cloud.vault.AppIdUserIdMechanism interface and the createUserId method. Spring Cloud Vault will obtain the UserId by calling createUserId each time it authenticates using AppId to obtain a token.

Example 4. bootstrap.yml
spring.cloud.vault:
    authentication: APPID
    app-id:
        user-id: com.examlple.MyUserIdMechanism
Example 5. MyUserIdMechanism.java
public class MyUserIdMechanism implements AppIdUserIdMechanism {

  @Override
  public String createUserId() {
    String userId = ...
    return userId;
  }
}

AppRole authentication

AppRole is intended for machine authentication, like the deprecated (since Vault 0.6.1) AppId authentication. AppRole authentication consists of two hard to guess (secret) tokens: RoleId and SecretId.

Spring Vault supports AppRole authentication by providing either RoleId only or together with a provided SecretId (push or pull mode).

RoleId and optionally SecretId must be provided by configuration, Spring Vault will not look up these or create a custom SecretId.

Example 6. bootstrap.yml with AppRole authentication properties
spring.cloud.vault:
    authentication: APPROLE
    app-role:
        role-id: bde2076b-cccb-3cf0-d57e-bca7b1e83a52
  • role-id sets the RoleId.

Example 7. bootstrap.yml with all AppRole authentication properties
spring.cloud.vault:
    authentication: APPROLE
    app-role:
        role-id: bde2076b-cccb-3cf0-d57e-bca7b1e83a52
        secret-id: 1696536f-1976-73b1-b241-0b4213908d39
        app-auth-path: approle
  • role-id sets the RoleId.

  • secret-id sets the SecretId. SecretId can be omitted if AppRole is configured without requiring SecretId (See bind_secret_id)

  • approle-path sets the path of the approle authentication mount to use

AWS-EC2 authentication

The aws-ec2 auth backend provides a secure introduction mechanism for AWS EC2 instances, allowing automated retrieval of a Vault token. Unlike most Vault authentication backends, this backend does not require first-deploying, or provisioning security-sensitive credentials (tokens, username/password, client certificates, etc.). Instead, it treats AWS as a Trusted Third Party and uses the cryptographically signed dynamic metadata information that uniquely represents each EC2 instance.

Example 8. bootstrap.yml using AWS-EC2 Authentication
spring.cloud.vault:
    authentication: AWS_EC2

AWS-EC2 authentication enables nonce by default to follow the Trust On First Use (TOFU) principle. Any unintended party that gains access to the PKCS#7 identity metadata can authenticate against Vault.

During the first login, Spring Cloud Vault generates a nonce that is stored in the auth backend aside the instance Id. Re-authentication requires the same nonce to be sent. Any other party does not have the nonce and can raise an alert in Vault for further investigation.

The nonce is kept in memory and is lost during application restart.

Example 9. bootstrap.yml with disabled nonce
spring.cloud.vault:
    authentication: AWS_EC2
    aws-ec2:
        use-nonce: false

AWS-EC2 authentication roles are optional and default to the AMI. You can configure the authentication role by setting the spring.cloud.vault.aws-ec2.role property.

Example 10. bootstrap.yml with configured role
spring.cloud.vault:
    authentication: AWS_EC2
    aws-ec2:
        role: application-server
Example 11. bootstrap.yml with all AWS EC2 authentication properties
spring.cloud.vault:
    authentication: AWS_EC2
    aws-ec2:
        role: application-server
        aws-ec2-path: aws-ec2
        identity-document: http://...
        use-nonce: false
  • authentication setting this value to AWS_EC2 selects the AWS EC2 authentication method

  • role sets the role name of the AWS EC2 role definition

  • aws-ec2-path sets the path of the AWS EC2 mount to use

  • identity-document sets URL of the PKCS#7 AWS EC2 identity document

  • use-nonce setting this value to false will disable nonce usage

TLS certificate authentication

The cert auth backend allows authentication using SSL/TLS client certificates that are either signed by a CA or self-signed.

To enable cert authentication you need to:

  1. Use SSL, see Vault Client SSL configuration

  2. Configure a Java Keystore that contains the client certificate and the private key

  3. Set the spring.cloud.vault.authentication to CERT

Example 12. bootstrap.yml
spring.cloud.vault:
    authentication: CERT
    ssl:
        key-store: classpath:keystore.jks
        key-store-password: changeit
        cert-auth-path: cert

Cubbyhole authentication

Cubbyhole authentication uses Vault primitives to provide a secured authentication workflow. Cubbyhole authentication uses tokens as primary login method. An ephemeral token is used to obtain a second, login VaultToken from Vault’s Cubbyhole secret backend. The login token is usually longer-lived and used to interact with Vault. The login token will be retrieved from a wrapped response stored at /cubbyhole/response.

Creating a wrapped token

Note
Response Wrapping for token creation requires Vault 0.6.0 or higher.
Example 13. Crating and storing tokens
$ vault token-create -wrap-ttl="10m"
Key                            Value
---                            -----
wrapping_token:                397ccb93-ff6c-b17b-9389-380b01ca2645
wrapping_token_ttl:            0h10m0s
wrapping_token_creation_time:  2016-09-18 20:29:48.652957077 +0200 CEST
wrapped_accessor:              46b6aebb-187f-932a-26d7-4f3d86a68319
Example 14. bootstrap.yml
spring.cloud.vault:
    authentication: CUBBYHOLE
    token: 397ccb93-ff6c-b17b-9389-380b01ca2645

See also:

Secret Backends

Generic Backend

Spring Cloud Vault supports at the basic level the generic secret backend. The generic secret backend allows storage of arbitrary values as key-value store. A single context can store one or many key-value tuples. Contexts can be organized hierarchically. Spring Cloud Vault allows using the Application name set in spring.application.name and a default context name (application) in combination with active profiles.

/secret/{application}/{profile}
/secret/{application}
/secret/{default-context}/{profile}
/secret/{default-context}

Spring Cloud Vault adds all active profiles to the list of possible context paths. No active profiles will skip accessing contexts with a profile name. Properties are exposed like they are stored (i.e. without additional prefixes).

spring.cloud.vault:
    generic:
        enabled: true
        backend: secret
        profile-separator: ','
        default-context: application
  • enabled setting this value to false disables the secret backend config usage

  • backend sets the path of the secret mount to use

  • default-context sets the context name used by all applications

  • profile-separator sets the value of the separator used to separate the profile name in property sources with profiles

Consul

Spring Cloud Vault can obtain credentials for HashiCorp Consul. The Consul integration requires the spring-cloud-vault-config-consul dependency.

Example 15. pom.xml
<dependencies>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-vault-config-consul</artifactId>
        <version>x.y.z</version>
    </dependency>
</dependencies>

The integration can be enabled by setting spring.cloud.vault.consul.enabled=true (default false) and providing the role name with spring.cloud.vault.consul.role=….

The obtained token is stored in spring.cloud.consul.token so using Spring Cloud Consul can pick up the generated credentials without further configuration. You can configure the property name by setting spring.cloud.vault.consul.token-property.

spring.cloud.vault:
    consul:
        enabled: true
        role: readonly
        backend: consul
        token-property: spring.cloud.consul.token
  • enabled setting this value to true enables the Consul backend config usage

  • role sets the role name of the Consul role definition

  • backend sets the path of the Consul mount to use

  • token-property sets the property name in which the Consul ACL token is stored

RabbitMQ

Spring Cloud Vault can obtain credentials for RabbitMQ.

The RabbitMQ integration requires the spring-cloud-vault-config-rabbitmq dependency.

Example 16. pom.xml
<dependencies>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-vault-config-rabbitmq</artifactId>
        <version>x.y.z</version>
    </dependency>
</dependencies>

The integration can be enabled by setting spring.cloud.vault.rabbitmq.enabled=true (default false) and providing the role name with spring.cloud.vault.rabbitmq.role=….

Username and password are stored in spring.rabbitmq.username and spring.rabbitmq.password so using Spring Boot will pick up the generated credentials without further configuration. You can configure the property names by setting spring.cloud.vault.rabbitmq.username-property and spring.cloud.vault.rabbitmq.password-property.

spring.cloud.vault:
    rabbitmq:
        enabled: true
        role: readonly
        backend: rabbitmq
        username-property: spring.rabbitmq.username
        password-property: spring.rabbitmq.password
  • enabled setting this value to true enables the RabbitMQ backend config usage

  • role sets the role name of the RabbitMQ role definition

  • backend sets the path of the RabbitMQ mount to use

  • username-property sets the property name in which the RabbitMQ username is stored

  • password-property sets the property name in which the RabbitMQ password is stored

AWS

Spring Cloud Vault can obtain credentials for AWS.

The AWS integration requires the spring-cloud-vault-config-aws dependency.

Example 17. pom.xml
<dependencies>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-vault-config-aws</artifactId>
        <version>x.y.z</version>
    </dependency>
</dependencies>

The integration can be enabled by setting spring.cloud.vault.aws=true (default false) and providing the role name with spring.cloud.vault.aws.role=….

The access key and secret key are stored in cloud.aws.credentials.accessKey and cloud.aws.credentials.secretKey so using Spring Cloud AWS will pick up the generated credentials without further configuration. You can configure the property names by setting spring.cloud.vault.aws.access-key-property and spring.cloud.vault.aws.secret-key-property.

spring.cloud.vault:
    aws:
        enabled: true
        role: readonly
        backend: aws
        access-key-property: cloud.aws.credentials.accessKey
        secret-key-property: cloud.aws.credentials.secretKey
  • enabled setting this value to true enables the AWS backend config usage

  • role sets the role name of the AWS role definition

  • backend sets the path of the AWS mount to use

  • access-key-property sets the property name in which the AWS access key is stored

  • secret-key-property sets the property name in which the AWS secret key is stored

Database backends

Vault supports several database secret backends to generate database credentials dynamically based on configured roles. This means services that need to access a database no longer need to configure credentials: they can request them from Vault, and use Vault’s leasing mechanism to more easily roll keys.

Spring Cloud Vault integrates with these backends:

Using a database secret backend requires to enable the backend in the configuration and the spring-cloud-vault-config-databases dependency.

Example 18. pom.xml
<dependencies>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-vault-config-databases</artifactId>
        <version>x.y.z</version>
    </dependency>
</dependencies>
Note
Enabling multiple JDBC-compliant databases will generate credentials and store them by default in the same property keys hence property names for JDBC secrets need to be configured separately.

Apache Cassandra

Spring Cloud Vault can obtain credentials for Apache Cassandra. The integration can be enabled by setting spring.cloud.vault.cassandra.enabled=true (default false) and providing the role name with spring.cloud.vault.cassandra.role=….

Username and password are stored in spring.data.cassandra.username and spring.data.cassandra.password so using Spring Boot will pick up the generated credentials without further configuration. You can configure the property names by setting spring.cloud.vault.cassandra.username-property and spring.cloud.vault.cassandra.password-property.

spring.cloud.vault:
    cassandra:
        enabled: true
        role: readonly
        backend: cassandra
        username-property: spring.data.cassandra.username
        password-property: spring.data.cassandra.username
  • enabled setting this value to true enables the Cassandra backend config usage

  • role sets the role name of the Cassandra role definition

  • backend sets the path of the Cassandra mount to use

  • username-property sets the property name in which the Cassandra username is stored

  • password-property sets the property name in which the Cassandra password is stored

MongoDB

Spring Cloud Vault can obtain credentials for MongoDB. The integration can be enabled by setting spring.cloud.vault.mongodb.enabled=true (default false) and providing the role name with spring.cloud.vault.mongodb.role=….

Username and password are stored in spring.data.mongodb.username and spring.data.mongodb.password so using Spring Boot will pick up the generated credentials without further configuration. You can configure the property names by setting spring.cloud.vault.mongodb.username-property and spring.cloud.vault.mongodb.password-property.

spring.cloud.vault:
    mongodb:
        enabled: true
        role: readonly
        backend: mongodb
        username-property: spring.data.mongodb.username
        password-property: spring.data.mongodb.password
  • enabled setting this value to true enables the MongodB backend config usage

  • role sets the role name of the MongoDB role definition

  • backend sets the path of the MongoDB mount to use

  • username-property sets the property name in which the MongoDB username is stored

  • password-property sets the property name in which the MongoDB password is stored

MySQL

Spring Cloud Vault can obtain credentials for MySQL. The integration can be enabled by setting spring.cloud.vault.mysql.enabled=true (default false) and providing the role name with spring.cloud.vault.mysql.role=….

Username and password are stored in spring.datasource.username and spring.datasource.password so using Spring Boot will pick up the generated credentials without further configuration. You can configure the property names by setting spring.cloud.vault.mysql.username-property and spring.cloud.vault.mysql.password-property.

spring.cloud.vault:
    mysql:
        enabled: true
        role: readonly
        backend: mysql
        username-property: spring.datasource.username
        password-property: spring.datasource.username
  • enabled setting this value to true enables the MySQL backend config usage

  • role sets the role name of the MySQL role definition

  • backend sets the path of the MySQL mount to use

  • username-property sets the property name in which the MySQL username is stored

  • password-property sets the property name in which the MySQL password is stored

PostgreSQL

Spring Cloud Vault can obtain credentials for PostgreSQL. The integration can be enabled by setting spring.cloud.vault.postgresql.enabled=true (default false) and providing the role name with spring.cloud.vault.postgresql.role=….

Username and password are stored in spring.datasource.username and spring.datasource.password so using Spring Boot will pick up the generated credentials without further configuration. You can configure the property names by setting spring.cloud.vault.postgresql.username-property and spring.cloud.vault.postgresql.password-property.

spring.cloud.vault:
    postgresql:
        enabled: true
        role: readonly
        backend: postgresql
        username-property: spring.datasource.username
        password-property: spring.datasource.username
  • enabled setting this value to true enables the PostgreSQL backend config usage

  • role sets the role name of the PostgreSQL role definition

  • backend sets the path of the PostgreSQL mount to use

  • username-property sets the property name in which the PostgreSQL username is stored

  • password-property sets the property name in which the PostgreSQL password is stored

Vault Client Fail Fast

In some cases, it may be desirable to fail startup of a service if it cannot connect to the Vault Server. If this is the desired behavior, set the bootstrap configuration property spring.cloud.vault.fail-fast=true and the client will halt with an Exception.

spring.cloud.vault:
    fail-fast: true

Vault Client SSL configuration

SSL can be configured declaratively by setting various properties. You can set either javax.net.ssl.trustStore to configure JVM-wide SSL settings or spring.cloud.vault.ssl.trust-store to set SSL settings only for Spring Cloud Vault Config.

spring.cloud.vault:
    ssl:
        trust-store: classpath:keystore.jks
        trust-store-password: changeit
  • trust-store sets the resource for the trust-store. SSL-secured Vault communication will validate the Vault SSL certificate with the specified trust-store.

  • trust-store-password sets the trust-store password

Please note that configuring spring.cloud.vault.ssl.* can be only applied when either Apache Http Components or the OkHttp client is on your class-path.

Lease lifecycle management (renewal and revocation)

With every secret, Vault creates a lease: metadata containing information such as a time duration, renewability, and more.

Vault promises that the data will be valid for the given duration, or Time To Live (TTL). Once the lease is expired, Vault can revoke the data, and the consumer of the secret can no longer be certain that it is valid.

Spring Cloud Vault maintains a lease lifecycle beyond the creation of login tokens and secrets. That said, login tokens and secrets associated with a lease are scheduled for renewal just before the lease expires until terminal expiry. Application shutdown revokes obtained login tokens and renewable leases.

Secret service and database backends (such as MongoDB or MySQL) usually generate a renewable lease so generated credentials will be disabled on application shutdown.

Note
Static tokens are not renewed or revoked.

Lease renewal and revocation is enabled by default and can be disabled by setting spring.cloud.vault.config.lifecycle.enabled to false. This is not recommended as leases can expire and Spring Cloud Vault cannot longer access Vault or services using generated credentials and valid credentials remain active after application shutdown.

spring.cloud.vault:
    config.lifecycle.enabled: true