path_config_connection.go

// Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: BUSL-1.1

package database

import (
	"context"
	"errors"
	"fmt"
	"net/url"
	"sort"
	"strings"

	"github.com/fatih/structs"
	"github.com/hashicorp/go-uuid"
	"github.com/hashicorp/go-version"
	"github.com/hashicorp/vault/helper/versions"
	v5 "github.com/hashicorp/vault/sdk/database/dbplugin/v5"
	"github.com/hashicorp/vault/sdk/framework"
	"github.com/hashicorp/vault/sdk/helper/consts"
	"github.com/hashicorp/vault/sdk/helper/pluginutil"
	"github.com/hashicorp/vault/sdk/logical"
)

var (
	respErrEmptyPluginName = "empty plugin name"
	respErrEmptyName       = "empty name attribute given"
)

// DatabaseConfig is used by the Factory function to configure a Database
// object.
type DatabaseConfig struct {
	PluginName           string `json:"plugin_name" structs:"plugin_name" mapstructure:"plugin_name"`
	PluginVersion        string `json:"plugin_version" structs:"plugin_version" mapstructure:"plugin_version"`
	RunningPluginVersion string `json:"running_plugin_version,omitempty" structs:"running_plugin_version,omitempty" mapstructure:"running_plugin_version,omitempty"`
	// ConnectionDetails stores the database specific connection settings needed
	// by each database type.
	ConnectionDetails map[string]interface{} `json:"connection_details" structs:"connection_details" mapstructure:"connection_details"`
	AllowedRoles      []string               `json:"allowed_roles" structs:"allowed_roles" mapstructure:"allowed_roles"`

	RootCredentialsRotateStatements []string `json:"root_credentials_rotate_statements" structs:"root_credentials_rotate_statements" mapstructure:"root_credentials_rotate_statements"`

	PasswordPolicy   string `json:"password_policy" structs:"password_policy" mapstructure:"password_policy"`
	VerifyConnection bool   `json:"verify_connection" structs:"verify_connection" mapstructure:"verify_connection"`
}

func (c *DatabaseConfig) SupportsCredentialType(credentialType v5.CredentialType) bool {
	credTypes, ok := c.ConnectionDetails[v5.SupportedCredentialTypesKey].([]interface{})
	if !ok {
		// Default to supporting CredentialTypePassword for database plugins that
		// don't specify supported credential types in the initialization response
		return credentialType == v5.CredentialTypePassword
	}

	for _, ct := range credTypes {
		if ct == credentialType.String() {
			return true
		}
	}
	return false
}

// pathResetConnection configures a path to reset a plugin.
func pathResetConnection(b *databaseBackend) *framework.Path {
	return &framework.Path{
		Pattern: fmt.Sprintf("reset/%s", framework.GenericNameRegex("name")),

		DisplayAttrs: &framework.DisplayAttributes{
			OperationPrefix: operationPrefixDatabase,
			OperationVerb:   "reset",
			OperationSuffix: "connection",
		},

		Fields: map[string]*framework.FieldSchema{
			"name": {
				Type:        framework.TypeString,
				Description: "Name of this database connection",
			},
		},

		Callbacks: map[logical.Operation]framework.OperationFunc{
			logical.UpdateOperation: b.pathConnectionReset(),
		},

		HelpSynopsis:    pathResetConnectionHelpSyn,
		HelpDescription: pathResetConnectionHelpDesc,
	}
}

// pathConnectionReset resets a plugin by closing the existing instance and
// creating a new one.
func (b *databaseBackend) pathConnectionReset() framework.OperationFunc {
	return func(ctx context.Context, req *logical.Request, data *framework.FieldData) (*logical.Response, error) {
		name := data.Get("name").(string)
		if name == "" {
			return logical.ErrorResponse(respErrEmptyName), nil
		}

		if err := b.reloadConnection(ctx, req.Storage, name); err != nil {
			return nil, err
		}

		b.dbEvent(ctx, "reset", req.Path, name, false)
		return nil, nil
	}
}

func (b *databaseBackend) reloadConnection(ctx context.Context, storage logical.Storage, name string) error {
	// Close plugin and delete the entry in the connections cache.
	if err := b.ClearConnection(name); err != nil {
		return err
	}

	// Execute plugin again, we don't need the object so throw away.
	if _, err := b.GetConnection(ctx, storage, name); err != nil {
		return err
	}

	return nil
}

// pathReloadPlugin reloads all connections using a named plugin.
func pathReloadPlugin(b *databaseBackend) *framework.Path {
	return &framework.Path{
		Pattern: fmt.Sprintf("reload/%s", framework.GenericNameRegex("plugin_name")),

		DisplayAttrs: &framework.DisplayAttributes{
			OperationPrefix: operationPrefixDatabase,
			OperationVerb:   "reload",
			OperationSuffix: "plugin",
		},

		Fields: map[string]*framework.FieldSchema{
			"plugin_name": {
				Type:        framework.TypeString,
				Description: "Name of the database plugin",
			},
		},

		Callbacks: map[logical.Operation]framework.OperationFunc{
			logical.UpdateOperation: b.reloadPlugin(),
		},

		HelpSynopsis:    pathReloadPluginHelpSyn,
		HelpDescription: pathReloadPluginHelpDesc,
	}
}

// reloadPlugin reloads all instances of a named plugin by closing the existing
// instances and creating new ones.
func (b *databaseBackend) reloadPlugin() framework.OperationFunc {
	return func(ctx context.Context, req *logical.Request, data *framework.FieldData) (*logical.Response, error) {
		pluginName := data.Get("plugin_name").(string)
		if pluginName == "" {
			return logical.ErrorResponse(respErrEmptyPluginName), nil
		}

		connNames, err := req.Storage.List(ctx, "config/")
		if err != nil {
			return nil, err
		}
		reloaded := []string{}
		for _, connName := range connNames {
			entry, err := req.Storage.Get(ctx, fmt.Sprintf("config/%s", connName))
			if err != nil {
				return nil, fmt.Errorf("failed to read connection configuration: %w", err)
			}
			if entry == nil {
				continue
			}

			var config DatabaseConfig
			if err := entry.DecodeJSON(&config); err != nil {
				return nil, err
			}
			if config.PluginName == pluginName {
				if err := b.reloadConnection(ctx, req.Storage, connName); err != nil {
					var successfullyReloaded string
					if len(reloaded) > 0 {
						successfullyReloaded = fmt.Sprintf("successfully reloaded %d connection(s): %s; ",
							len(reloaded),
							strings.Join(reloaded, ", "))
					}
					return nil, fmt.Errorf("%sfailed to reload connection %q: %w", successfullyReloaded, connName, err)
				}
				reloaded = append(reloaded, connName)
			}
		}

		resp := &logical.Response{
			Data: map[string]interface{}{
				"connections": reloaded,
				"count":       len(reloaded),
			},
		}

		if len(reloaded) == 0 {
			resp.AddWarning(fmt.Sprintf("no connections were found with plugin_name %q", pluginName))
		}
		b.dbEvent(ctx, "reload", req.Path, "", true, "plugin_name", pluginName)
		return resp, nil
	}
}

// pathConfigurePluginConnection returns a configured framework.Path setup to
// operate on plugins.
func pathConfigurePluginConnection(b *databaseBackend) *framework.Path {
	return &framework.Path{
		Pattern: fmt.Sprintf("config/%s", framework.GenericNameRegex("name")),

		DisplayAttrs: &framework.DisplayAttributes{
			OperationPrefix: operationPrefixDatabase,
		},

		Fields: map[string]*framework.FieldSchema{
			"name": {
				Type:        framework.TypeString,
				Description: "Name of this database connection",
			},

			"plugin_name": {
				Type: framework.TypeString,
				Description: `The name of a builtin or previously registered
				plugin known to vault. This endpoint will create an instance of
				that plugin type.`,
			},

			"plugin_version": {
				Type:        framework.TypeString,
				Description: `The version of the plugin to use.`,
			},

			"verify_connection": {
				Type:    framework.TypeBool,
				Default: true,
				Description: `If true, the connection details are verified by
				actually connecting to the database. Defaults to true.`,
			},

			"allowed_roles": {
				Type: framework.TypeCommaStringSlice,
				Description: `Comma separated string or array of the role names
				allowed to get creds from this database connection. If empty no
				roles are allowed. If "*" all roles are allowed.`,
			},

			"root_rotation_statements": {
				Type: framework.TypeStringSlice,
				Description: `Specifies the database statements to be executed
				to rotate the root user's credentials. See the plugin's API 
				page for more information on support and formatting for this 
				parameter.`,
			},
			"password_policy": {
				Type:        framework.TypeString,
				Description: `Password policy to use when generating passwords.`,
			},
		},

		ExistenceCheck: b.connectionExistenceCheck(),

		Operations: map[logical.Operation]framework.OperationHandler{
			logical.CreateOperation: &framework.PathOperation{
				Callback: b.connectionWriteHandler(),
				DisplayAttrs: &framework.DisplayAttributes{
					OperationVerb:   "configure",
					OperationSuffix: "connection",
				},
			},
			logical.UpdateOperation: &framework.PathOperation{
				Callback: b.connectionWriteHandler(),
				DisplayAttrs: &framework.DisplayAttributes{
					OperationVerb:   "configure",
					OperationSuffix: "connection",
				},
			},
			logical.ReadOperation: &framework.PathOperation{
				Callback: b.connectionReadHandler(),
				DisplayAttrs: &framework.DisplayAttributes{
					OperationVerb:   "read",
					OperationSuffix: "connection-configuration",
				},
			},
			logical.DeleteOperation: &framework.PathOperation{
				Callback: b.connectionDeleteHandler(),
				DisplayAttrs: &framework.DisplayAttributes{
					OperationVerb:   "delete",
					OperationSuffix: "connection-configuration",
				},
			},
		},

		HelpSynopsis:    pathConfigConnectionHelpSyn,
		HelpDescription: pathConfigConnectionHelpDesc,
	}
}

func (b *databaseBackend) connectionExistenceCheck() framework.ExistenceFunc {
	return func(ctx context.Context, req *logical.Request, data *framework.FieldData) (bool, error) {
		name := data.Get("name").(string)
		if name == "" {
			return false, errors.New(`missing "name" parameter`)
		}

		entry, err := req.Storage.Get(ctx, fmt.Sprintf("config/%s", name))
		if err != nil {
			return false, fmt.Errorf("failed to read connection configuration: %w", err)
		}

		return entry != nil, nil
	}
}

func pathListPluginConnection(b *databaseBackend) *framework.Path {
	return &framework.Path{
		Pattern: fmt.Sprintf("config/?$"),

		DisplayAttrs: &framework.DisplayAttributes{
			OperationPrefix: operationPrefixDatabase,
			OperationSuffix: "connections",
		},

		Callbacks: map[logical.Operation]framework.OperationFunc{
			logical.ListOperation: b.connectionListHandler(),
		},

		HelpSynopsis:    pathConfigConnectionHelpSyn,
		HelpDescription: pathConfigConnectionHelpDesc,
	}
}

func (b *databaseBackend) connectionListHandler() framework.OperationFunc {
	return func(ctx context.Context, req *logical.Request, data *framework.FieldData) (*logical.Response, error) {
		entries, err := req.Storage.List(ctx, "config/")
		if err != nil {
			return nil, err
		}

		return logical.ListResponse(entries), nil
	}
}

// connectionReadHandler reads out the connection configuration
func (b *databaseBackend) connectionReadHandler() framework.OperationFunc {
	return func(ctx context.Context, req *logical.Request, data *framework.FieldData) (*logical.Response, error) {
		name := data.Get("name").(string)
		if name == "" {
			return logical.ErrorResponse(respErrEmptyName), nil
		}

		entry, err := req.Storage.Get(ctx, fmt.Sprintf("config/%s", name))
		if err != nil {
			return nil, fmt.Errorf("failed to read connection configuration: %w", err)
		}
		if entry == nil {
			return nil, nil
		}

		var config DatabaseConfig
		if err := entry.DecodeJSON(&config); err != nil {
			return nil, err
		}

		// Ensure that we only ever include a redacted valid URL in the response.
		if connURLRaw, ok := config.ConnectionDetails["connection_url"]; ok {
			if p, err := url.Parse(connURLRaw.(string)); err == nil {
				config.ConnectionDetails["connection_url"] = p.Redacted()
			}
		}

		if versions.IsBuiltinVersion(config.PluginVersion) {
			// This gets treated as though it's empty when mounting, and will get
			// overwritten to be empty when the config is next written. See #18051.
			config.PluginVersion = ""
		}

		delete(config.ConnectionDetails, "password")
		delete(config.ConnectionDetails, "private_key")
		delete(config.ConnectionDetails, "service_account_json")

		resp := &logical.Response{}
		if dbi, err := b.GetConnectionSkipVerify(ctx, req.Storage, name); err == nil {
			config.RunningPluginVersion = dbi.runningPluginVersion
			if config.PluginVersion != "" && config.PluginVersion != config.RunningPluginVersion {
				warning := fmt.Sprintf("Plugin version is configured as %q, but running %q", config.PluginVersion, config.RunningPluginVersion)
				if pinnedVersion, _ := b.getPinnedVersion(ctx, config.PluginName); pinnedVersion == config.RunningPluginVersion {
					warning += " because that version is pinned"
				} else {
					warning += " either due to a pinned version or because the plugin was upgraded and not yet reloaded"
				}
				resp.AddWarning(warning)
			}
		}

		resp.Data = structs.New(config).Map()
		return resp, nil
	}
}

// connectionDeleteHandler deletes the connection configuration
func (b *databaseBackend) connectionDeleteHandler() framework.OperationFunc {
	return func(ctx context.Context, req *logical.Request, data *framework.FieldData) (*logical.Response, error) {
		name := data.Get("name").(string)
		if name == "" {
			return logical.ErrorResponse(respErrEmptyName), nil
		}

		err := req.Storage.Delete(ctx, fmt.Sprintf("config/%s", name))
		if err != nil {
			return nil, fmt.Errorf("failed to delete connection configuration: %w", err)
		}

		if err := b.ClearConnection(name); err != nil {
			return nil, err
		}

		b.dbEvent(ctx, "config-delete", req.Path, name, true)
		return nil, nil
	}
}

// connectionWriteHandler returns a handler function for creating and updating
// both builtin and plugin database types.
func (b *databaseBackend) connectionWriteHandler() framework.OperationFunc {
	return func(ctx context.Context, req *logical.Request, data *framework.FieldData) (*logical.Response, error) {
		name := data.Get("name").(string)
		if name == "" {
			return logical.ErrorResponse(respErrEmptyName), nil
		}

		// Baseline
		config := &DatabaseConfig{
			VerifyConnection: true,
		}

		entry, err := req.Storage.Get(ctx, fmt.Sprintf("config/%s", name))
		if err != nil {
			return nil, fmt.Errorf("failed to read connection configuration: %w", err)
		}
		if entry != nil {
			if err := entry.DecodeJSON(config); err != nil {
				return nil, err
			}
		}

		// If this value was provided as part of the request we want to set it to this value
		if verifyConnectionRaw, ok := data.GetOk("verify_connection"); ok {
			config.VerifyConnection = verifyConnectionRaw.(bool)
		} else if req.Operation == logical.CreateOperation {
			config.VerifyConnection = data.Get("verify_connection").(bool)
		}

		if pluginNameRaw, ok := data.GetOk("plugin_name"); ok {
			config.PluginName = pluginNameRaw.(string)
		} else if req.Operation == logical.CreateOperation {
			config.PluginName = data.Get("plugin_name").(string)
		}
		if config.PluginName == "" {
			return logical.ErrorResponse(respErrEmptyPluginName), nil
		}

		pluginVersion, respErr, err := b.selectPluginVersion(ctx, config, data, req.Operation)
		if respErr != nil || err != nil {
			return respErr, err
		}

		if allowedRolesRaw, ok := data.GetOk("allowed_roles"); ok {
			config.AllowedRoles = allowedRolesRaw.([]string)
		} else if req.Operation == logical.CreateOperation {
			config.AllowedRoles = data.Get("allowed_roles").([]string)
		}

		if rootRotationStatementsRaw, ok := data.GetOk("root_rotation_statements"); ok {
			config.RootCredentialsRotateStatements = rootRotationStatementsRaw.([]string)
		} else if req.Operation == logical.CreateOperation {
			config.RootCredentialsRotateStatements = data.Get("root_rotation_statements").([]string)
		}

		if passwordPolicyRaw, ok := data.GetOk("password_policy"); ok {
			config.PasswordPolicy = passwordPolicyRaw.(string)
		}

		// Remove these entries from the data before we store it keyed under
		// ConnectionDetails.
		delete(data.Raw, "name")
		delete(data.Raw, "plugin_name")
		delete(data.Raw, "plugin_version")
		delete(data.Raw, "allowed_roles")
		delete(data.Raw, "verify_connection")
		delete(data.Raw, "root_rotation_statements")
		delete(data.Raw, "password_policy")

		id, err := uuid.GenerateUUID()
		if err != nil {
			return nil, err
		}

		// If this is an update, take any new values, overwrite what was there
		// before, and pass that in as the "new" set of values to the plugin,
		// then save what results
		if req.Operation == logical.CreateOperation {
			config.ConnectionDetails = data.Raw
		} else {
			if config.ConnectionDetails == nil {
				config.ConnectionDetails = make(map[string]interface{})
			}
			for k, v := range data.Raw {
				config.ConnectionDetails[k] = v
			}
		}

		// Create a database plugin and initialize it.
		dbw, err := newDatabaseWrapper(ctx, config.PluginName, pluginVersion, b.System(), b.logger)
		if err != nil {
			return logical.ErrorResponse("error creating database object: %s", err), nil
		}

		initReq := v5.InitializeRequest{
			Config:           config.ConnectionDetails,
			VerifyConnection: config.VerifyConnection,
		}
		initResp, err := dbw.Initialize(ctx, initReq)
		if err != nil {
			dbw.Close()
			return logical.ErrorResponse("error creating database object: %s", err), nil
		}
		config.ConnectionDetails = initResp.Config

		b.Logger().Debug("created database object", "name", name, "plugin_name", config.PluginName)

		// Close and remove the old connection
		oldConn := b.connections.Put(name, &dbPluginInstance{
			database:             dbw,
			name:                 name,
			id:                   id,
			runningPluginVersion: pluginVersion,
		})
		if oldConn != nil {
			oldConn.Close()
		}

		// 1.12.0 and 1.12.1 stored builtin plugins in storage, but 1.12.2 reverted
		// that, so clean up any pre-existing stored builtin versions on write.
		if versions.IsBuiltinVersion(config.PluginVersion) {
			config.PluginVersion = ""
		}
		err = storeConfig(ctx, req.Storage, name, config)
		if err != nil {
			return nil, err
		}

		resp := &logical.Response{}

		// This is a simple test to check for passwords in the connection_url parameter. If one exists,
		// warn the user to use templated url string
		if connURLRaw, ok := config.ConnectionDetails["connection_url"]; ok {
			if connURL, err := url.Parse(connURLRaw.(string)); err == nil {
				if _, ok := connURL.User.Password(); ok {
					resp.AddWarning("Password found in connection_url, use a templated url to enable root rotation and prevent read access to password information.")
				}
			}
		}

		// If using a legacy DB plugin and set the `password_policy` field, send a warning to the user indicating
		// the `password_policy` will not be used
		if dbw.isV4() && config.PasswordPolicy != "" {
			resp.AddWarning(fmt.Sprintf("%s does not support password policies - upgrade to the latest version of "+
				"Vault (or the sdk if using a custom plugin) to gain password policy support", config.PluginName))
		}

		b.dbEvent(ctx, "config-write", req.Path, name, true)
		if len(resp.Warnings) == 0 {
			return nil, nil
		}
		return resp, nil
	}
}

func storeConfig(ctx context.Context, storage logical.Storage, name string, config *DatabaseConfig) error {
	entry, err := logical.StorageEntryJSON(fmt.Sprintf("config/%s", name), config)
	if err != nil {
		return fmt.Errorf("unable to marshal object to JSON: %w", err)
	}

	err = storage.Put(ctx, entry)
	if err != nil {
		return fmt.Errorf("failed to save object: %w", err)
	}
	return nil
}

func (b *databaseBackend) getPinnedVersion(ctx context.Context, pluginName string) (string, error) {
	extendedSys, ok := b.System().(logical.ExtendedSystemView)
	if !ok {
		return "", fmt.Errorf("database backend does not support running as an external plugin")
	}

	pin, err := extendedSys.GetPinnedPluginVersion(ctx, consts.PluginTypeDatabase, pluginName)
	if errors.Is(err, pluginutil.ErrPinnedVersionNotFound) {
		return "", nil
	}
	if err != nil {
		return "", err
	}

	return pin.Version, nil
}

func (b *databaseBackend) selectPluginVersion(ctx context.Context, config *DatabaseConfig, data *framework.FieldData, op logical.Operation) (string, *logical.Response, error) {
	pinnedVersion, err := b.getPinnedVersion(ctx, config.PluginName)
	if err != nil {
		return "", nil, err
	}
	pluginVersionRaw, ok := data.GetOk("plugin_version")

	switch {
	case ok && pinnedVersion != "":
		return "", logical.ErrorResponse("cannot specify plugin_version for plugin %q as it is pinned (v%s)", config.PluginName, pinnedVersion), nil
	case pinnedVersion != "":
		return pinnedVersion, nil, nil
	case ok:
		config.PluginVersion = pluginVersionRaw.(string)
	}

	var builtinShadowed bool
	if unversionedPlugin, err := b.System().LookupPlugin(ctx, config.PluginName, consts.PluginTypeDatabase); err == nil && !unversionedPlugin.Builtin {
		builtinShadowed = true
	}
	switch {
	case config.PluginVersion != "":
		semanticVersion, err := version.NewVersion(config.PluginVersion)
		if err != nil {
			return "", logical.ErrorResponse("version %q is not a valid semantic version: %s", config.PluginVersion, err), nil
		}

		// Canonicalize the version.
		config.PluginVersion = "v" + semanticVersion.String()

		if config.PluginVersion == versions.GetBuiltinVersion(consts.PluginTypeDatabase, config.PluginName) {
			if builtinShadowed {
				return "", logical.ErrorResponse("database plugin %q, version %s not found, as it is"+
					" overridden by an unversioned plugin of the same name. Omit `plugin_version` to use the unversioned plugin", config.PluginName, config.PluginVersion), nil
			}

			config.PluginVersion = ""
		}
	case builtinShadowed:
		// We'll select the unversioned plugin that's been registered.
	case op == logical.CreateOperation:
		// No version provided and no unversioned plugin of that name available.
		// Pin to the current latest version if any versioned plugins are registered.
		plugins, err := b.System().ListVersionedPlugins(ctx, consts.PluginTypeDatabase)
		if err != nil {
			return "", nil, err
		}

		var versionedCandidates []pluginutil.VersionedPlugin
		for _, plugin := range plugins {
			if !plugin.Builtin && plugin.Name == config.PluginName && plugin.Version != "" {
				versionedCandidates = append(versionedCandidates, plugin)
			}
		}

		if len(versionedCandidates) != 0 {
			// Sort in reverse order.
			sort.SliceStable(versionedCandidates, func(i, j int) bool {
				return versionedCandidates[i].SemanticVersion.GreaterThan(versionedCandidates[j].SemanticVersion)
			})

			config.PluginVersion = "v" + versionedCandidates[0].SemanticVersion.String()
			b.logger.Debug(fmt.Sprintf("pinning %q database plugin version %q from candidates %v", config.PluginName, config.PluginVersion, versionedCandidates))
		}
	}

	return config.PluginVersion, nil, nil
}

const pathConfigConnectionHelpSyn = `
Configure connection details to a database plugin.
`

const pathConfigConnectionHelpDesc = `
This path configures the connection details used to connect to a particular
database. This path runs the provided plugin name and passes the configured
connection details to the plugin. See the documentation for the plugin specified
for a full list of accepted connection details. 

In addition to the database specific connection details, this endpoint also
accepts:

	* "plugin_name" (required) - The name of a builtin or previously registered
	   plugin known to vault. This endpoint will create an instance of that
	   plugin type.

	* "verify_connection" (default: true) - A boolean value denoting if the plugin should verify
	   it is able to connect to the database using the provided connection
       details.
`

const pathResetConnectionHelpSyn = `
Resets a database plugin.
`

const pathResetConnectionHelpDesc = `
This path resets the database connection by closing the existing database plugin
instance and running a new one.
`

const pathReloadPluginHelpSyn = `
Reloads all connections using a named database plugin.
`

const pathReloadPluginHelpDesc = `
This path resets each database connection using a named plugin by closing each
existing database plugin instance and running a new one.
`