The Vault CLI command to query information about the token the client is currently using is vault token lookup. This command displays information about the token or accessor provided as an argument, or the locally authenticated token if no argument is given. The information includes the token ID, accessor, policies, TTL, creation time, and metadata. This command can be useful for debugging and auditing purposes, as well as for renewing or revoking tokens. References: token lookup - Command | Vault | HashiCorp Developer, Tokens | Vault | HashiCorp Developer

The root token is the initial token created when initializing Vault. It has unlimited privileges and can perform any operation in Vault. As a best practice, the root token should be revoked and never stored after initial setup. This is because the root token is a single point of failure and a potential security risk if it is compromised or leaked. Instead of using the root token, Vault operators should create other tokens with appropriate policies and roles that allow them to perform their tasks. If a new root token is needed in an emergency, the vault operator generate-root command can be used to create one on-the-fly with the consent of a quorum of unseal key holders. References: Tokens | Vault | HashiCorp Developer, Generate root tokens using unseal keys | Vault | HashiCorp Developer

The statement is false. An organization can authenticate an AWS EC2 virtual machine with Vault to access a dynamic database secret using more than one authentication method. The AWS auth method is one of the options, but not the only one. The AWS auth method supports two types of authentication: ec2 and iam. The ec2 type uses the signed EC2 instance identity document to authenticate the EC2 instance. The iam type uses the AWS Signature v4 algorithm to sign a request to the sts:GetCallerIdentity API and authenticate the IAM principal. However, the organization can also use other auth methods that are compatible with EC2 instances, suchas AppRole, JWT/OIDC, or Kubernetes. These methods require the EC2 instance to have some sort of identity material, such as a role ID, a secret ID, a JWT token, or a service account token, that can be used to authenticate to Vault. The identity material can be provisioned to the EC2 instance using various mechanisms, such as user data, metadata service, or cloud-init scripts. The choice of the auth method depends on the use case, the security requirements, and the trade-offs between convenience and control. References: AWS - Auth Methods | Vault | HashiCorp Developer, AppRole - Auth Methods | Vault | HashiCorp Developer, JWT/OIDC - Auth Methods | Vault | HashiCorp Developer, Kubernetes - Auth Methods | Vault | HashiCorp Developer

The statement is true. When an auth method is disabled, all users authenticated via that method lose access. This is because the tokens issued by the auth method are automatically revoked when the auth method is disabled. This prevents the users from performing any operation in Vault using the revoked tokens. To regain access, the users have to authenticate again using a different auth method that is enabled and has the appropriate policies attached. References: Auth Methods | Vault | HashiCorp Developer, auth disable - Command | Vault | HashiCorp Developer

The statement is false. The Vault encryption key is not stored in Vault’s backend storage, but rather in Vault’s memory. The Vault encryption key is the key that is used to encrypt and decrypt the data that is stored in Vault’s backend storage, such as secrets, tokens, policies, etc. The Vault encryption key is derived from the master key, which is generated when Vault is initialized. The master key is split into unseal keys using Shamir’s secret sharing algorithm, and the unseal keys are distributed to trusted operators. To start Vault, a quorum of unseal keys is required to reconstruct the master key and derive the encryption key. The encryption key is then kept in memory and used to protect the data in Vault’s backend storage. The encryption key is never written to disk or exposed via the API. References: Seal/Unseal | Vault | HashiCorp Developer, Key Rotation | Vault | HashiCorp Developer

AppRole is a machine-oriented authentication method that allows machines or applications to authenticate with Vault using a role ID and a secret ID. The role ID is aunique identifier for the application, and the secret ID is a single-use credential that can be delivered to the application securely. AppRole is designed to provide secure introduction of machines and applications to Vault, and to support the principle of least privilege by allowing fine-grained access control policies to be attached to each role1.

Okta, GitHub, and Transit are not machine-oriented authentication methods. Okta and GitHub are user-oriented authentication methods that allow users to authenticate with Vault using their Okta or GitHub credentials23. Transit is not an authentication method at all, but a secrets engine that provides encryption as a service4.

References:

• AppRole Auth Method | Vault | HashiCorp Developer
• Okta Auth Method | Vault | HashiCorp Developer
• GitHub Auth Method | Vault | HashiCorp Developer
• Transit Secrets Engine | Vault | HashiCorp Developer

An authentication method should be selected for a use case based on the auth method that best establishes the identity of the client. The identity of the client is the basis for assigning a set of policies and permissions to the client in Vault. Different auth methods have different ways of verifying the identity of the client, such as using passwords, tokens, certificates, cloud credentials, etc. Depending on the use case, some auth methods may be more suitable or convenient than others. For example, for human users, the userpass or ldap auth methods may be easy to use, while for machines or applications, the approle or aws auth methods may be more secure and scalable. The choice of the auth method should also consider the trade-offs between security, performance, and usability. References: Auth Methods | Vault | HashiCorp Developer, Authentication - Concepts | Vault | HashiCorp Developer

The policy shown in the image is:

path “secret/data/webapp1” { capabilities = [“create”, “read”, “update”, “delete”, “list”] }

path “secret/data/super-secret” { capabilities = [“deny”] }

This policy grants or denies access to the key/value v2 secrets engine mounted at secret/ according to the following rules:

• The path “secret/data/webapp1” has the capabilities of “create”, “read”, “update”, “delete”, and “list”. This means that the policy allows performing any of these operations on the secrets stored under this path. The data/ prefix is used to access the actual secret data in the key/value v2 secrets engine5. Therefore, the policy permits the operation of vault kv get secret/webapp1, which reads the secret data at secret/data/webapp16.
• The path “secret/data/super-secret” has the capability of “deny”. This means that the policy denies performing any operation on the secrets stored under this path. The policy overrides any other policy that might grant access to this path. Therefore, the policy does not permit the operations of vault kv delete secret/super-secret and vault kv list secret/super-secret, which delete and list the secret data at secret/data/super-secret respectively6.
• The policy does not explicitly define any rules for the path “secret/metadata”. The metadata/ prefix is used to access the metadata of the secrets in the key/value v2 secrets engine, such as the number of versions, the deletion status, the creation time, etc5. By default, if the policy grants any of the capabilities of “create”, “read”, “update”, or “delete” on the data/ path, it also grants the same capabilities on the corresponding metadata/ path7. Therefore, the policy permits the operation of vault kv metadata get secret/webapp1, which reads the metadata of the secret at secret/metadata/webapp18.

References: 5(https://developer.hashicorp.com/vault/docs/secrets/kv/kv-v2), [ 6]6, 7(https://developer.hashicorp.com/vault/docs/secrets/kv/kv-v2), [ 8]8

Using a short-lived dynamic secrets can help limit the scope of a credential breach by reducing the exposure time of the secrets. Dynamic secrets are generated on-demand by Vault and automatically revoked when they are no longer needed. This way, the credentials are not stored in plain text or in a static database, and they can be rotated frequently to prevent unauthorized access. Dynamic secrets also provide encryption as a service, which means that they perform cryptographic operations on data in-transit without storing any data. This adds an extra layer of security and reduces the risk of data leakage or tampering. References: Dynamic secrets | Vault | HashiCorp Developer, What are dynamic secrets and why do I need them? - HashiCorp

To make an authenticated request via the Vault HTTP API, you need to use the X-Vault-Token HTTP Header or the Authorization HTTP Header using the Bearer scheme. The token is a string that represents your identity and permissions in Vault. You can obtain a token by using an authentication method, such as userpass, approle, aws, etc. The token can also be a root token, which has unlimited access to Vault, or a wrapped token, which is a response-wrapping token that can be used to unwrap the actual token. The token must be sent with every request to Vault that requires authentication, except for the unauthenticated endpoints, such as sys/init, sys/seal-status, sys/unseal, etc. The token is used by Vault to verify your identity and enforce the policies that grant or deny access to various paths and operations. References: https://developer.hashicorp.com/vault/api-docs 3, https://developer.hashicorp.com/vault/docs/concepts/tokens 4, https://developer.hashicorp.com/vault/docs/concepts/auth 5

A web application that uses Vault’s transit secrets engine to encrypt data in-transit can benefit from the following security features:

• Even if the attacker was able to access the raw data, they would only have encrypted bits (TLS in transit). This means that the attacker would need to obtain the encryption key from Vault in order to decrypt the data, which is protected by Vault’s authentication and authorization mechanisms. The transit secrets engine does not store the data sent to it, so the attacker cannot access the data from Vault either.
• The keys can be rotated and min_decryption_version moved forward to ensure this data cannot be decrypted. This means that the web application can periodically change the encryption key used to encrypt the data, and set a minimum decryption version for the key, which prevents older versions of the key from being used to decrypt the data. This way, even if the attacker somehow obtained an old version of the key, they would not be able to decrypt the data that was encrypted with a newer version of the key.

The other statements are not true, because:

• You cannot rotate the encryption key so that the attacker won’t be able to decrypt the data. Rotating the key alone does not prevent the attacker from decrypting the data, as they may still have access to the old version of the key that was used to encrypt the data. You need to also move the min_decryption_version forward to invalidate the old version of the key.
• The Vault administrator would not need to seal the Vault server immediately. Sealing the Vault server would make it inaccessible to both the attacker and the legitimate users, and would require unsealing it with the unseal keys or the recovery keys. Sealing the Vault server is a last resort option in case of a severe compromise or emergency, and is not necessary in this scenario, as the attacker does not have access to the encryption key or the data in Vault. References: Transit - Secrets Engines | Vault | HashiCorp Developer, Encryption as a service: transit secrets engine | Vault | HashiCorp Developer

This policy would allow read permissions for all secrets at path secret/bar, as well as list permissions for the secret/bar/ path. The list permission is required to be able to see the names of the secrets under a given path1. The wildcard () character matches any number of characters within a single path segment, while the slash (/) character matches the end of the path2. Therefore, the policy would grant read access to any secret that starts with secret/bar/, such as secret/bar/foo or secret/bar/baz, but not to secret/bar itself. To grant list access to secret/bar, the policy needs to specify the exact path with a slash at the end. This policy follows the principle of least privilege, which means that it only grants the minimum permissions necessary for the users to perform their tasks3.

The other options are not correct because they either grant too much or too little permissions. Option A would grant both read and list permissions to all secrets under secret/bar, which is more than what is required. Option B would grant list permissions to all secrets under secret/bar, but only read permissions to secret/bar itself, which is not what is required. Option D would use an invalid character (+) in the policy, which would cause an error.

References:

• Policy Syntax | Vault | HashiCorp Developer
• Policy Syntax | Vault | HashiCorp Developer
• Policies | Vault | HashiCorp Developer

When looking at Vault token details, the policies key helps you find the paths the token is able to access. Policies are a declarative way to grant or forbid access to certain paths and operations in Vault. Policies are written in HCL or JSON and are attached to tokens by name. Policies are deny by default, so an empty policy grants no permission in the system. A token can have one or more policies associated with it, and the effective policy is the union of all the individual policies. You can view the token details by using the vault token lookup command or the auth/token/lookup API endpoint. The output will show the policies key with a list of policy names that are attached to the token. You can also view the contents of a policy by using the vault policy read command or the sys/policy API endpoint. The output will show the rules key with the HCL or JSON representation of the policy. The rules will specify the paths and the capabilities (such as create, read, update, delete, list, etc.) that the policy allows or denies. References: https://developer.hashicorp.com/vault/docs/concepts/policies 4, https://developer.hashicorp.com/vault/docs/commands/token/lookup 5, https://developer.hashicorp.com/vault/api-docs/auth/token#lookup-a-token 6,https://developer.hashicorp.com/vault/docs/commands/policy/read 7, https://developer.hashicorp.com/vault/api-docs/system/policy 8

Vault supports CIDR-bound tokens, which are tokens that can only be used from a specific set of IP addresses or network ranges. This is a way to limit the scope and exposure of a token in case it is compromised or leaked. CIDR-bound tokens can be created by specifying the bound_cidr_list parameter when creating or updating a token role, or by using the -bound-cidr option when creating a token using the vault token create command. CIDR-bound tokens can also be created by some auth methods, such as AWS or Kubernetes, that can automatically bind the tokens to the source IP or network of the client. References: Token - Auth Methods | Vault | HashiCorp Developer, vault token create - Command | Vault | HashiCorp Developer