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diff --git a/doc/radosgw/vault.rst b/doc/radosgw/vault.rst new file mode 100644 index 000000000..da34a3919 --- /dev/null +++ b/doc/radosgw/vault.rst @@ -0,0 +1,442 @@ +=========================== +HashiCorp Vault Integration +=========================== + +HashiCorp `Vault`_ can be used as a secure key management service for +`Server-Side Encryption`_ (SSE-KMS). + +.. ditaa:: + + +---------+ +---------+ +-------+ +-------+ + | Client | | RadosGW | | Vault | | OSD | + +---------+ +---------+ +-------+ +-------+ + | create secret | | | + | key for key ID | | | + |-----------------+---------------->| | + | | | | + | upload object | | | + | with key ID | | | + |---------------->| request secret | | + | | key for key ID | | + | |---------------->| | + | |<----------------| | + | | return secret | | + | | key | | + | | | | + | | encrypt object | | + | | with secret key | | + | |--------------+ | | + | | | | | + | |<-------------+ | | + | | | | + | | store encrypted | | + | | object | | + | |------------------------------>| + +#. `Vault secrets engines`_ +#. `Vault authentication`_ +#. `Vault namespaces`_ +#. `Create a key in Vault`_ +#. `Configure the Ceph Object Gateway`_ +#. `Upload object`_ + +Some examples below use the Vault command line utility to interact with +Vault. You may need to set the following environment variable with the correct +address of your Vault server to use this utility:: + + export VAULT_ADDR='https://vault-server-fqdn:8200' + +Vault secrets engines +===================== + +Vault provides several secrets engines, which can store, generate, and encrypt +data. Currently, the Object Gateway supports: + +- `KV secrets engine`_ version 2 +- `Transit engine`_ + +KV secrets engine +----------------- + +The KV secrets engine is used to store arbitrary key/value secrets in Vault. To +enable the KV engine version 2 in Vault, use the following command:: + + vault secrets enable -path secret kv-v2 + +The Object Gateway can be configured to use the KV engine version 2 with the +following setting:: + + rgw crypt vault secret engine = kv + +Transit secrets engine +---------------------- + +The transit engine handles cryptographic functions on data in-transit. To enable +it in Vault, use the following command:: + + vault secrets enable transit + +The Object Gateway can be configured to use the transit engine with the +following setting:: + + rgw crypt vault secret engine = transit + +Vault authentication +==================== + +Vault supports several authentication mechanisms. Currently, the Object +Gateway can be configured to authenticate to Vault using the +`Token authentication method`_ or a `Vault agent`_. + +Most tokens in Vault have limited lifetimes and powers. The only +sort of Vault token that does not have a lifetime are root tokens. +For all other tokens, it is necessary to periodically refresh them, +either by performing initial authentication, or by renewing the token. +Ceph does not have any logic to perform either operation. +The simplest best way to use Vault tokens with ceph is to +also run the Vault agent and have it refresh the token file. +When the Vault agent is used in this mode, file system permissions +can be used to restrict who has the use of tokens. + +Instead of having Vault agent refresh a token file, it can be told +to act as a proxy server. In this mode, Vault will add a token when +necessary and add it to requests passed to it before forwarding them on +to the real server. Vault agent will still handle token renewal just +as it would when storing a token in the filesystem. In this mode, it +is necessary to properly secure the network path rgw uses to reach the +Vault agent, such as having the Vault agent listen only to localhost. + +Token policies for the object gateway +------------------------------------- + +All Vault tokens have powers as specified by the polices attached +to that token. Multiple policies may be associated with one +token. You should only use the policies necessary for your +configuration. + +When using the kv secret engine with the object gateway:: + + vault policy write rgw-kv-policy -<<EOF + path "secret/data/*" { + capabilities = ["read"] + } + EOF + +When using the transit secret engine with the object gateway:: + + vault policy write rgw-transit-policy -<<EOF + path "transit/keys/*" { + capabilities = [ "create", "update" ] + denied_parameters = {"exportable" = [], "allow_plaintext_backup" = [] } + } + + path "transit/keys/*" { + capabilities = ["read", "delete"] + } + + path "transit/keys/" { + capabilities = ["list"] + } + + path "transit/keys/+/rotate" { + capabilities = [ "update" ] + } + + path "transit/*" { + capabilities = [ "update" ] + } + EOF + +If you had previously used an older version of ceph with the +transit secret engine, you might need the following policy:: + + vault policy write old-rgw-transit-policy -<<EOF + path "transit/export/encryption-key/*" { + capabilities = ["read"] + } + EOF + +If you are using both sse-kms and sse-s3, then you should point +each to separate containers. You could either use separate +vault instances, or you could use either separately mounted +transit instances, or different branches under a common transit +point. If you are not using separate vault instances, you can +use these to point kms and sse-s3 to separate containers: +``rgw_crypt_vault_prefix`` +and/or +``rgw_crypt_sse_s3_vault_prefix``. +When granting vault permissions to sse-kms bucket owners, you should +not give them permission to muck around with sse-s3 keys; +only ceph itself should be doing that. + +Token authentication +-------------------- + +.. note: Never use root tokens with ceph in production environments. + +The token authentication method expects a Vault token to be present in a +plaintext file. The Object Gateway can be configured to use token authentication +with the following settings:: + + rgw crypt vault auth = token + rgw crypt vault token file = /run/.rgw-vault-token + rgw crypt vault addr = https://vault-server-fqdn:8200 + +Adjust these settings to match your configuration. +For security reasons, the token file must be readable by the Object Gateway +only. + +Vault agent +----------- + +The Vault agent is a client daemon that provides authentication to Vault and +manages token renewal and caching. It typically runs on the same host as the +Object Gateway. With a Vault agent, it is possible to use other Vault +authentication mechanism such as AppRole, AWS, Certs, JWT, and Azure. + +The Object Gateway can be configured to use a Vault agent with the following +settings:: + + rgw crypt vault auth = agent + rgw crypt vault addr = http://127.0.0.1:8100 + +You might set up vault agent as follows:: + + vault write auth/approle/role/rgw-ap \ + token_policies=rgw-transit-policy,default \ + token_max_ttl=60m + +Change the policy here to match your configuration. + +Get the role-id: + vault read auth/approle/role/rgw-ap/role-id -format=json | \ + jq -r .data.role_id + +Store the output in some file, such as /usr/local/etc/vault/.rgw-ap-role-id + +Get the secret-id: + vault read auth/approle/role/rgw-ap/role-id -format=json | \ + jq -r .data.role_id + +Store the output in some file, such as /usr/local/etc/vault/.rgw-ap-secret-id + +Create configuration for the Vault agent, such as:: + + pid_file = "/run/rgw-vault-agent-pid" + auto_auth { + method "AppRole" { + mount_path = "auth/approle" + config = { + role_id_file_path ="/usr/local/etc/vault/.rgw-ap-role-id" + secret_id_file_path ="/usr/local/etc/vault/.rgw-ap-secret-id" + remove_secret_id_file_after_reading ="false" + } + } + } + cache { + use_auto_auth_token = true + } + listener "tcp" { + address = "127.0.0.1:8100" + tls_disable = true + } + vault { + address = "https://vault-server-fqdn:8200" + } + +Then use systemctl or another method of your choice to run +a persistent daemon with the following arguments:: + + /usr/local/bin/vault agent -config=/usr/local/etc/vault/rgw-agent.hcl + +Once the vault agent is running, you should find it listening +to port 8100 on localhost, and you should be able to interact +with it using the vault command. + +Vault namespaces +================ + +In the Enterprise version, Vault supports the concept of `namespaces`_, which +allows centralized management for teams within an organization while ensuring +that those teams operate within isolated environments known as tenants. + +The Object Gateway can be configured to access Vault within a particular +namespace using the following configuration setting:: + + rgw crypt vault namespace = tenant1 + +Create a key in Vault +===================== + +.. note:: Keys for server-side encryption must be 256-bit long and base-64 + encoded. + +Using the KV engine +------------------- + +A key for server-side encryption can be created in the KV version 2 engine using +the command line utility, as in the following example:: + + vault kv put secret/myproject/mybucketkey key=$(openssl rand -base64 32) + +Sample output:: + + ====== Metadata ====== + Key Value + --- ----- + created_time 2019-08-29T17:01:09.095824999Z + deletion_time n/a + destroyed false + version 1 + +Note that in the KV secrets engine, secrets are stored as key-value pairs, and +the Gateway expects the key name to be ``key``, i.e. the secret must be in the +form ``key=<secret key>``. + +Using the Transit engine +------------------------ + +Keys created for use with the Transit engine should no longer be marked +exportable. They can be created with:: + + vault write -f transit/keys/mybucketkey + +The command above creates a keyring, which contains a key of type +``aes256-gcm96`` by default. To verify that the key was correctly created, use +the following command:: + + vault read transit/keys/mybucketkey + +Sample output:: + + Key Value + --- ----- + derived false + exportable false + name mybucketkey + type aes256-gcm96 + +Configure the Ceph Object Gateway +================================= + +Edit the Ceph configuration file to enable Vault as a KMS backend for +server-side encryption:: + + rgw crypt s3 kms backend = vault + +Choose the Vault authentication method, e.g.:: + + rgw crypt vault auth = token + rgw crypt vault token file = /run/.rgw-vault-token + rgw crypt vault addr = https://vault-server-fqdn:8200 + +Or:: + + rgw crypt vault auth = agent + rgw crypt vault addr = http://localhost:8100 + +Choose the secrets engine:: + + rgw crypt vault secret engine = kv + +Or:: + + rgw crypt vault secret engine = transit + +Optionally, set the Vault namespace where encryption keys will be fetched from:: + + rgw crypt vault namespace = tenant1 + +Finally, the URLs where the Gateway will retrieve encryption keys from Vault can +be restricted by setting a path prefix. For instance, the Gateway can be +restricted to fetch KV keys as follows:: + + rgw crypt vault prefix = /v1/secret/data + +Or, when using the transit secret engine:: + + rgw crypt vault prefix = /v1/transit + +In the example above, the Gateway would only fetch transit encryption keys under +``https://vault-server:8200/v1/transit``. + +You can use custom ssl certs to authenticate with vault with help of +following options:: + + rgw crypt vault verify ssl = true + rgw crypt vault ssl cacert = /etc/ceph/vault.ca + rgw crypt vault ssl clientcert = /etc/ceph/vault.crt + rgw crypt vault ssl clientkey = /etc/ceph/vault.key + +where vault.ca is CA certificate and vault.key/vault.crt are private key and ssl +certificate generated for RGW to access the vault server. It highly recommended to +set this option true, setting false is very dangerous and need to avoid since this +runs in very secured environments. + +Transit engine compatibility support +------------------------------------ +The transit engine has compatibility support for previous +versions of ceph, which used the transit engine as a simple key store. + +There is a "compat" option which can be given to the transit +engine to configure the compatibility support, + +To entirely disable backwards support, use:: + + rgw crypt vault secret engine = transit compat=0 + +This will be the default in future versions. and is safe to use +for new installs using the current version. + +This is the normal default with the current version:: + + rgw crypt vault secret engine = transit compat=1 + +This enables the new engine for newly created objects, +but still allows the old engine to be used for old objects. +In order to access old and new objects, the vault token given +to ceph must have both the old and new transit policies. + +To force use of only the old engine, use:: + + rgw crypt vault secret engine = transit compat=2 + +This mode is automatically selected if the vault prefix +ends in export/encryption-key, which was the previously +documented setting. + +Upload object +============= + +When uploading an object to the Gateway, provide the SSE key ID in the request. +As an example, for the kv engine, using the AWS command-line client:: + + aws --endpoint=http://radosgw:8000 s3 cp plaintext.txt s3://mybucket/encrypted.txt --sse=aws:kms --sse-kms-key-id myproject/mybucketkey + +As an example, for the transit engine (new flavor), using the AWS command-line client:: + + aws --endpoint=http://radosgw:8000 s3 cp plaintext.txt s3://mybucket/encrypted.txt --sse=aws:kms --sse-kms-key-id mybucketkey + +The Object Gateway will fetch the key from Vault, encrypt the object and store +it in the bucket. Any request to download the object will make the Gateway +automatically retrieve the correspondent key from Vault and decrypt the object. + +Note that the secret will be fetched from Vault using a URL constructed by +concatenating the base address (``rgw crypt vault addr``), the (optional) +URL prefix (``rgw crypt vault prefix``), and finally the key ID. + +In the kv engine example above, the Gateway would fetch the secret from:: + + http://vaultserver:8200/v1/secret/data/myproject/mybucketkey + +In the transit engine example above, the Gateway would encrypt the secret using this key:: + + http://vaultserver:8200/v1/transit/mybucketkey + +.. _Server-Side Encryption: ../encryption +.. _Vault: https://www.vaultproject.io/docs/ +.. _Token authentication method: https://www.vaultproject.io/docs/auth/token.html +.. _Vault agent: https://www.vaultproject.io/docs/agent/index.html +.. _KV Secrets engine: https://www.vaultproject.io/docs/secrets/kv/ +.. _Transit engine: https://www.vaultproject.io/docs/secrets/transit +.. _namespaces: https://www.vaultproject.io/docs/enterprise/namespaces/index.html |