open-vault/logical/plugin/pb/backend.proto

syntax = "proto3";
package pb;

import "google/protobuf/timestamp.proto";

message Empty {}

message Header {
	repeated string header = 1;
}

message ProtoError {
	// Error type can be one of:
	// ErrTypeUnknown uint32 = iota
	// ErrTypeUserError
	// ErrTypeInternalError
	// ErrTypeCodedError
	// ErrTypeStatusBadRequest
	// ErrTypeUnsupportedOperation
	// ErrTypeUnsupportedPath
	// ErrTypeInvalidRequest
	// ErrTypePermissionDenied
	// ErrTypeMultiAuthzPending
	uint32 err_type = 1;
	string err_msg = 2;
	int64 err_code = 3;
}

// Paths is the structure of special paths that is used for SpecialPaths.
message  Paths {
	// Root are the paths that require a root token to access
	repeated string root = 1;

	// Unauthenticated are the paths that can be accessed without any auth.
	repeated string unauthenticated = 2;

	// LocalStorage are paths (prefixes) that are local to this instance; this
	// indicates that these paths should not be replicated
	repeated string local_storage = 3;

	// SealWrapStorage are storage paths that, when using a capable seal,
	// should be seal wrapped with extra encryption. It is exact matching
	// unless it ends with '/' in which case it will be treated as a prefix.
	repeated string seal_wrap_storage = 4;
}

message Request {
	// Id is the uuid associated with each request
	string id = 1;

	// If set, the name given to the replication secondary where this request
	// originated
	string ReplicationCluster = 2;

	// Operation is the requested operation type
	string operation = 3;

	// Path is the part of the request path not consumed by the
	// routing. As an example, if the original request path is "prod/aws/foo"
	// and the AWS logical backend is mounted at "prod/aws/", then the
	// final path is "foo" since the mount prefix is trimmed.
	string path = 4;

	// Request data is a JSON object that must have keys with string type.
	string data = 5;

	// Secret will be non-nil only for Revoke and Renew operations
	// to represent the secret that was returned prior.
	Secret secret = 6;

	// Auth will be non-nil only for Renew operations
	// to represent the auth that was returned prior.
	Auth auth = 7;

	// Headers will contain the http headers from the request. This value will
	// be used in the audit broker to ensure we are auditing only the allowed
	// headers.
	map<string, Header> headers = 8;

	// ClientToken is provided to the core so that the identity
	// can be verified and ACLs applied. This value is passed
	// through to the logical backends but after being salted and
	// hashed.
	string client_token = 9;

	// ClientTokenAccessor is provided to the core so that the it can get
	// logged as part of request audit logging.
	string client_token_accessor = 10;

	// DisplayName is provided to the logical backend to help associate
	// dynamic secrets with the source entity. This is not a sensitive
	// name, but is useful for operators.
	string display_name = 11;

	// MountPoint is provided so that a logical backend can generate
	// paths relative to itself. The `Path` is effectively the client
	// request path with the MountPoint trimmed off.
	string mount_point = 12;

	// MountType is provided so that a logical backend can make decisions
	// based on the specific mount type (e.g., if a mount type has different
	// aliases, generating different defaults depending on the alias)
	string mount_type = 13;

	// MountAccessor is provided so that identities returned by the authentication
	// backends can be tied to the mount it belongs to.
	string mount_accessor = 14;

	// WrapInfo contains requested response wrapping parameters
	RequestWrapInfo wrap_info = 15;

	// ClientTokenRemainingUses represents the allowed number of uses left on the
	// token supplied
	int64 client_token_remaining_uses = 16;

	// EntityID is the identity of the caller extracted out of the token used
	// to make this request
	string entity_id = 17;

	// PolicyOverride indicates that the requestor wishes to override
	// soft-mandatory Sentinel policies
	bool policy_override = 18;

	// Whether the request is unauthenticated, as in, had no client token
	// attached. Useful in some situations where the client token is not made
	// accessible.
	bool unauthenticated = 19;

   	// Connection will be non-nil only for credential providers to
	// inspect the connection information and potentially use it for
	// authentication/protection.
	Connection connection = 20;
}

message Alias {
	// MountType is the backend mount's type to which this identity belongs
	string mount_type = 1;

	// MountAccessor is the identifier of the mount entry to which this
	// identity belongs
	string mount_accessor = 2;

	// Name is the identifier of this identity in its authentication source
	string name = 3;
}

message Auth {
	LeaseOptions lease_options = 1;

	// InternalData is a JSON object that is stored with the auth struct.
	// This will be sent back during a Renew/Revoke for storing internal data
	// used for those operations.
	string internal_data = 2;

	// DisplayName is a non-security sensitive identifier that is
	// applicable to this Auth. It is used for logging and prefixing
	// of dynamic secrets. For example, DisplayName may be "armon" for
	// the github credential backend. If the client token is used to
	// generate a SQL credential, the user may be "github-armon-uuid".
	// This is to help identify the source without using audit tables.
	string display_name = 3;

	// Policies is the list of policies that the authenticated user
	// is associated with.
	repeated string policies = 4;

	// Metadata is used to attach arbitrary string-type metadata to
	// an authenticated user. This metadata will be outputted into the
	// audit log.
	map<string, string> metadata = 5;

	// ClientToken is the token that is generated for the authentication.
	// This will be filled in by Vault core when an auth structure is
	// returned. Setting this manually will have no effect.
	string client_token = 6;

	// Accessor is the identifier for the ClientToken. This can be used
	// to perform management functionalities (especially revocation) when
	// ClientToken in the audit logs are obfuscated. Accessor can be used
	// to revoke a ClientToken and to lookup the capabilities of the ClientToken,
	// both without actually knowing the ClientToken.
	string accessor = 7;

	// Period indicates that the token generated using this Auth object
	// should never expire. The token should be renewed within the duration
	// specified by this period.
	int64 period = 8;

	// Number of allowed uses of the issued token
	int64 num_uses = 9;

	// EntityID is the identifier of the entity in identity store to which the
	// identity of the authenticating client belongs to.
	string entity_id = 10;

	// Alias is the information about the authenticated client returned by
	// the auth backend
	Alias alias = 11;

	// GroupAliases are the informational mappings of external groups which an
	// authenticated user belongs to. This is used to check if there are
	// mappings groups for the group aliases in identity store. For all the
	// matching groups, the entity ID of the user will be added.
	repeated Alias group_aliases = 12;
}

message LeaseOptions {
	int64 TTL = 1;
	
	bool renewable = 2;

	int64 increment = 3;

	google.protobuf.Timestamp issue_time = 4;

	int64 MaxTTL = 5;
}

message Secret {
	LeaseOptions lease_options = 1;

	// InternalData is a JSON object that is stored with the secret.
	// This will be sent back during a Renew/Revoke for storing internal data
	// used for those operations.
	string internal_data = 2;

	// LeaseID is the ID returned to the user to manage this secret.
	// This is generated by Vault core. Any set value will be ignored.
	// For requests, this will always be blank.
	string lease_id = 3;
}

message Response {
	// Secret, if not nil, denotes that this response represents a secret.
	Secret secret = 1;

	// Auth, if not nil, contains the authentication information for
	// this response. This is only checked and means something for
	// credential backends.
	Auth auth = 2;

	// Response data is a JSON object that must have string keys. For
	// secrets, this data is sent down to the user as-is. To store internal
	// data that you don't want the user to see, store it in
	// Secret.InternalData.
	string data = 3;

	// Redirect is an HTTP URL to redirect to for further authentication.
	// This is only valid for credential backends. This will be blanked
	// for any logical backend and ignored.
	string redirect = 4;

	// Warnings allow operations or backends to return warnings in response
	// to user actions without failing the action outright.
	repeated string warnings = 5;

	// Information for wrapping the response in a cubbyhole
	ResponseWrapInfo wrap_info = 6;
}

message ResponseWrapInfo {
	// Setting to non-zero specifies that the response should be wrapped.
	// Specifies the desired TTL of the wrapping token.
	int64 TTL = 1;

	// The token containing the wrapped response
	string token = 2;

	// The token accessor for the wrapped response token
	string accessor = 3;

	// The creation time. This can be used with the TTL to figure out an
	// expected expiration.
	google.protobuf.Timestamp creation_time = 4;

	// If the contained response is the output of a token creation call, the
	// created token's accessor will be accessible here
	string wrapped_accessor = 5;

	// WrappedEntityID is the entity identifier of the caller who initiated the
	// wrapping request
	string wrapped_entity_id = 6;

	// The format to use. This doesn't get returned, it's only internal.
	string format = 7;

	// CreationPath is the original request path that was used to create
	// the wrapped response.
	string creation_path = 8;

	// Controls seal wrapping behavior downstream for specific use cases
	bool seal_wrap = 9;
}

message RequestWrapInfo {
	// Setting to non-zero specifies that the response should be wrapped.
	// Specifies the desired TTL of the wrapping token.
	int64 TTL = 1;

	// The format to use for the wrapped response; if not specified it's a bare
	// token
	string format = 2;

	// A flag to conforming backends that data for a given request should be
	// seal wrapped
	bool seal_wrap = 3;
}

// HandleRequestArgs is the args for HandleRequest method.
message HandleRequestArgs {
	uint32 storage_id = 1;
	Request request = 2;
}

// HandleRequestReply is the reply for HandleRequest method.
message HandleRequestReply {
	Response response = 1;
	ProtoError err = 2;
}

// SpecialPathsReply is the reply for SpecialPaths method.
message SpecialPathsReply {
	Paths paths = 1;
}

// HandleExistenceCheckArgs is the args for HandleExistenceCheck method.
message HandleExistenceCheckArgs {
	uint32 storage_id = 1;
	Request  request = 2;
}

// HandleExistenceCheckReply is the reply for HandleExistenceCheck method.
message HandleExistenceCheckReply {
	bool check_found = 1;
	bool exists = 2;
	ProtoError err = 3;
}

// SetupArgs is the args for Setup method.
message SetupArgs {
	uint32 broker_id = 1; 
	map<string, string> Config = 2;
	string backendUUID = 3;
}

// SetupReply is the reply for Setup method.
message SetupReply {
	string err = 1;
}

// TypeReply is the reply for the Type method.
message TypeReply {
	uint32 type = 1;
}

message InvalidateKeyArgs {
	string key = 1;
}

// Backend is the interface that plugins must satisfy. The plugin should
// implement the server for this service. Requests will first run the
// HandleExistenceCheck rpc then run the HandleRequests rpc.
service Backend {
	// HandleRequest is used to handle a request and generate a response.
	// The plugins must check the operation type and handle appropriately.
	rpc HandleRequest(HandleRequestArgs) returns (HandleRequestReply);

	// SpecialPaths is a list of paths that are special in some way.
	// See PathType for the types of special paths. The key is the type
	// of the special path, and the value is a list of paths for this type.
	// This is not a regular expression but is an exact match. If the path
	// ends in '*' then it is a prefix-based match. The '*' can only appear
	// at the end.
	rpc SpecialPaths(Empty) returns (SpecialPathsReply);

	// HandleExistenceCheck is used to handle a request and generate a response
	// indicating whether the given path exists or not; this is used to
	// understand whether the request must have a Create or Update capability
	// ACL applied. The first bool indicates whether an existence check
	// function was found for the backend; the second indicates whether, if an
	// existence check function was found, the item exists or not.
	rpc HandleExistenceCheck(HandleExistenceCheckArgs) returns (HandleExistenceCheckReply);

	// Cleanup is invoked during an unmount of a backend to allow it to
	// handle any cleanup like connection closing or releasing of file handles.
	// Cleanup is called right before Vault closes the plugin process.
	rpc Cleanup(Empty) returns (Empty);

	// InvalidateKey may be invoked when an object is modified that belongs
	// to the backend. The backend can use this to clear any caches or reset
	// internal state as needed.
	rpc InvalidateKey(InvalidateKeyArgs) returns (Empty);

	// Setup is used to set up the backend based on the provided backend
	// configuration. The plugin's setup implementation should use the provided
	// broker_id to create a connection back to Vault for use with the Storage
	// and SystemView clients.
	rpc Setup(SetupArgs) returns (SetupReply);

   	// Type returns the BackendType for the particular backend
	rpc Type(Empty) returns (TypeReply);
}

message StorageEntry {
	string key = 1;
	bytes value = 2;
	bool seal_wrap = 3;
}

message StorageListArgs {
	string prefix = 1;
}

message StorageListReply {
	repeated string keys = 1;
	string err = 2;
}

message StorageGetArgs {
	string key = 1;
}

message StorageGetReply {
	StorageEntry entry = 1;
	string err = 2;
}

message StoragePutArgs {
	StorageEntry entry = 1;
}

message StoragePutReply {
	string err = 1;
}

message StorageDeleteArgs {
	string key = 1;
}

message StorageDeleteReply {
	string err = 1;
}

// Storage is the way that plugins are able read/write data. Plugins should
// implement the client for this service.
service Storage {
	rpc List(StorageListArgs) returns (StorageListReply);
	rpc Get(StorageGetArgs) returns (StorageGetReply);
	rpc Put(StoragePutArgs) returns (StoragePutReply);
	rpc Delete(StorageDeleteArgs) returns (StorageDeleteReply);
}

message TTLReply {
	int64 TTL = 1;
}

message SudoPrivilegeArgs {
	string path = 1;
	string token = 2;
}

message SudoPrivilegeReply {
	bool sudo = 1;
}

message TaintedReply {
	bool tainted = 1;
}

message CachingDisabledReply {
	bool disabled = 1;
}

message ReplicationStateReply {
	int32 state = 1;
}

message ResponseWrapDataArgs {
	string data = 1;
	int64 TTL = 2;
	bool JWT = 3;
}

message ResponseWrapDataReply {
	ResponseWrapInfo wrap_info = 1;
	string err = 2;
}

message MlockEnabledReply {
	bool enabled = 1;
}

message LocalMountReply {
	bool local = 1;
}

// SystemView exposes system configuration information in a safe way for plugins
// to consume. Plugins should implement the client for this service.
service SystemView {
  	// DefaultLeaseTTL returns the default lease TTL set in Vault configuration
	rpc DefaultLeaseTTL(Empty) returns (TTLReply);
	
   	// MaxLeaseTTL returns the max lease TTL set in Vault configuration; backend
	// authors should take care not to issue credentials that last longer than
	// this value, as Vault will revoke them
	rpc MaxLeaseTTL(Empty) returns (TTLReply);

	// SudoPrivilege returns true if given path has sudo privileges
	// for the given client token
	rpc SudoPrivilege(SudoPrivilegeArgs) returns (SudoPrivilegeReply);

	// Tainted, returns true if the mount is tainted. A mount is tainted if it is in the
	// process of being unmounted. This should only be used in special
	// circumstances; a primary use-case is as a guard in revocation functions.
	// If revocation of a backend's leases fails it can keep the unmounting
	// process from being successful. If the reason for this failure is not
	// relevant when the mount is tainted (for instance, saving a CRL to disk
	// when the stored CRL will be removed during the unmounting process
	// anyways), we can ignore the errors to allow unmounting to complete.
	rpc Tainted(Empty) returns (TaintedReply);

	// CachingDisabled returns true if caching is disabled. If true, no caches
	// should be used, despite known slowdowns.
	rpc CachingDisabled(Empty) returns (CachingDisabledReply);

   	// ReplicationState indicates the state of cluster replication
	rpc ReplicationState(Empty) returns (ReplicationStateReply);

	// ResponseWrapData wraps the given data in a cubbyhole and returns the
	// token used to unwrap.
	rpc ResponseWrapData(ResponseWrapDataArgs) returns (ResponseWrapDataReply);

	// MlockEnabled returns the configuration setting for enabling mlock on
	// plugins.
	rpc MlockEnabled(Empty) returns (MlockEnabledReply);

	// LocalMount, when run from a system view attached to a request, indicates
	// whether the request is affecting a local mount or not
	rpc LocalMount(Empty) returns (LocalMountReply);
}

message Connection {
	// RemoteAddr is the network address that sent the request.
	string remote_addr = 1;
}