package vault

import (
	"context"
	"errors"
	"fmt"
	"strings"
	"time"

	"github.com/armon/go-metrics"
	"github.com/hashicorp/errwrap"
	"github.com/hashicorp/go-multierror"
	sockaddr "github.com/hashicorp/go-sockaddr"
	"github.com/hashicorp/vault/audit"
	"github.com/hashicorp/vault/helper/consts"
	"github.com/hashicorp/vault/helper/errutil"
	"github.com/hashicorp/vault/helper/identity"
	"github.com/hashicorp/vault/helper/jsonutil"
	"github.com/hashicorp/vault/helper/policyutil"
	"github.com/hashicorp/vault/helper/strutil"
	"github.com/hashicorp/vault/helper/wrapping"
	"github.com/hashicorp/vault/logical"
	"github.com/hashicorp/vault/logical/framework"
)

const (
	replTimeout = 10 * time.Second
)

var (
	// DefaultMaxRequestDuration is the amount of time we'll wait for a request
	// to complete, unless overridden on a per-handler basis
	DefaultMaxRequestDuration = 90 * time.Second
)

// HandlerProperties is used to seed configuration into a vaulthttp.Handler.
// It's in this package to avoid a circular dependency
type HandlerProperties struct {
	Core                  *Core
	MaxRequestSize        int64
	MaxRequestDuration    time.Duration
	DisablePrintableCheck bool
}

// fetchEntityAndDerivedPolicies returns the entity object for the given entity
// ID. If the entity is merged into a different entity object, the entity into
// which the given entity ID is merged into will be returned. This function
// also returns the cumulative list of policies that the entity is entitled to.
// This list includes the policies from the entity itself and from all the
// groups in which the given entity ID is a member of.
func (c *Core) fetchEntityAndDerivedPolicies(entityID string) (*identity.Entity, []string, error) {
	if entityID == "" || c.identityStore == nil {
		return nil, nil, nil
	}

	//c.logger.Debug("entity set on the token", "entity_id", te.EntityID)

	// Fetch the entity
	entity, err := c.identityStore.MemDBEntityByID(entityID, false)
	if err != nil {
		c.logger.Error("failed to lookup entity using its ID", "error", err)
		return nil, nil, err
	}

	if entity == nil {
		// If there was no corresponding entity object found, it is
		// possible that the entity got merged into another entity. Try
		// finding entity based on the merged entity index.
		entity, err = c.identityStore.MemDBEntityByMergedEntityID(entityID, false)
		if err != nil {
			c.logger.Error("failed to lookup entity in merged entity ID index", "error", err)
			return nil, nil, err
		}
	}

	var policies []string
	if entity != nil {
		//c.logger.Debug("entity successfully fetched; adding entity policies to token's policies to create ACL")

		// Attach the policies on the entity
		policies = append(policies, entity.Policies...)

		groupPolicies, err := c.identityStore.groupPoliciesByEntityID(entity.ID)
		if err != nil {
			c.logger.Error("failed to fetch group policies", "error", err)
			return nil, nil, err
		}

		// Attach the policies from all the groups
		policies = append(policies, groupPolicies...)
	}

	return entity, policies, err
}

func (c *Core) fetchACLTokenEntryAndEntity(req *logical.Request) (*ACL, *logical.TokenEntry, *identity.Entity, []string, error) {
	defer metrics.MeasureSince([]string{"core", "fetch_acl_and_token"}, time.Now())

	// Ensure there is a client token
	if req.ClientToken == "" {
		return nil, nil, nil, nil, fmt.Errorf("missing client token")
	}

	if c.tokenStore == nil {
		c.logger.Error("token store is unavailable")
		return nil, nil, nil, nil, ErrInternalError
	}

	// Resolve the token policy
	var te *logical.TokenEntry
	switch req.TokenEntry() {
	case nil:
		var err error
		te, err = c.tokenStore.Lookup(c.activeContext, req.ClientToken)
		if err != nil {
			c.logger.Error("failed to lookup token", "error", err)
			return nil, nil, nil, nil, ErrInternalError
		}
	default:
		te = req.TokenEntry()
	}

	// Ensure the token is valid
	if te == nil {
		return nil, nil, nil, nil, logical.ErrPermissionDenied
	}

	// CIDR checks bind all tokens except non-expiring root tokens
	if te.TTL != 0 && len(te.BoundCIDRs) > 0 {
		var valid bool
		remoteSockAddr, err := sockaddr.NewSockAddr(req.Connection.RemoteAddr)
		if err != nil {
			if c.Logger().IsDebug() {
				c.Logger().Debug("could not parse remote addr into sockaddr", "error", err, "remote_addr", req.Connection.RemoteAddr)
			}
			return nil, nil, nil, nil, logical.ErrPermissionDenied
		}
		for _, cidr := range te.BoundCIDRs {
			if cidr.Contains(remoteSockAddr) {
				valid = true
				break
			}
		}
		if !valid {
			return nil, nil, nil, nil, logical.ErrPermissionDenied
		}
	}

	entity, identityPolicies, err := c.fetchEntityAndDerivedPolicies(te.EntityID)
	if err != nil {
		return nil, nil, nil, nil, ErrInternalError
	}

	allPolicies := append(te.Policies, identityPolicies...)

	// Construct the corresponding ACL object
	acl, err := c.policyStore.ACL(c.activeContext, entity, allPolicies...)
	if err != nil {
		if errwrap.ContainsType(err, new(TemplateError)) {
			return nil, nil, nil, nil, err
		}
		c.logger.Error("failed to construct ACL", "error", err)
		return nil, nil, nil, nil, ErrInternalError
	}

	return acl, te, entity, identityPolicies, nil
}

func (c *Core) checkToken(ctx context.Context, req *logical.Request, unauth bool) (*logical.Auth, *logical.TokenEntry, error) {
	defer metrics.MeasureSince([]string{"core", "check_token"}, time.Now())

	var acl *ACL
	var te *logical.TokenEntry
	var entity *identity.Entity
	var identityPolicies []string
	var err error

	// Even if unauth, if a token is provided, there's little reason not to
	// gather as much info as possible for the audit log and to e.g. control
	// trace mode for EGPs.
	if !unauth || (unauth && req.ClientToken != "") {
		acl, te, entity, identityPolicies, err = c.fetchACLTokenEntryAndEntity(req)
		// In the unauth case we don't want to fail the command, since it's
		// unauth, we just have no information to attach to the request, so
		// ignore errors...this was best-effort anyways
		if err != nil && !unauth {
			if errwrap.ContainsType(err, new(TemplateError)) {
				c.logger.Warn("permission denied due to a templated policy being invalid or containing directives not satisfied by the requestor")
				err = logical.ErrPermissionDenied
			}
			return nil, te, err
		}
	}

	if entity != nil && entity.Disabled {
		c.logger.Warn("permission denied as the entity on the token is disabled")
		return nil, te, logical.ErrPermissionDenied
	}
	if te != nil && te.EntityID != "" && entity == nil {
		c.logger.Warn("permission denied as the entity on the token is invalid")
		return nil, te, logical.ErrPermissionDenied
	}

	// Check if this is a root protected path
	rootPath := c.router.RootPath(req.Path)

	if rootPath && unauth {
		return nil, nil, errors.New("cannot access root path in unauthenticated request")
	}

	// When we receive a write of either type, rather than require clients to
	// PUT/POST and trust the operation, we ask the backend to give us the real
	// skinny -- if the backend implements an existence check, it can tell us
	// whether a particular resource exists. Then we can mark it as an update
	// or creation as appropriate.
	if req.Operation == logical.CreateOperation || req.Operation == logical.UpdateOperation {
		checkExists, resourceExists, err := c.router.RouteExistenceCheck(ctx, req)
		switch err {
		case logical.ErrUnsupportedPath:
			// fail later via bad path to avoid confusing items in the log
			checkExists = false
		case nil:
			// Continue on
		default:
			c.logger.Error("failed to run existence check", "error", err)
			if _, ok := err.(errutil.UserError); ok {
				return nil, nil, err
			} else {
				return nil, nil, ErrInternalError
			}
		}

		switch {
		case checkExists == false:
			// No existence check, so always treat it as an update operation, which is how it is pre 0.5
			req.Operation = logical.UpdateOperation
		case resourceExists == true:
			// It exists, so force an update operation
			req.Operation = logical.UpdateOperation
		case resourceExists == false:
			// It doesn't exist, force a create operation
			req.Operation = logical.CreateOperation
		default:
			panic("unreachable code")
		}
	}
	// Create the auth response
	auth := &logical.Auth{
		ClientToken:      req.ClientToken,
		Accessor:         req.ClientTokenAccessor,
		Policies:         identityPolicies,
		IdentityPolicies: identityPolicies,
	}

	if te != nil {
		auth.TokenPolicies = te.Policies
		auth.Policies = append(te.Policies, identityPolicies...)
		auth.Metadata = te.Meta
		auth.DisplayName = te.DisplayName
		auth.EntityID = te.EntityID
		// Store the entity ID in the request object
		req.EntityID = te.EntityID
	}

	// Check the standard non-root ACLs. Return the token entry if it's not
	// allowed so we can decrement the use count.
	authResults := c.performPolicyChecks(ctx, acl, te, req, entity, &PolicyCheckOpts{
		Unauth:            unauth,
		RootPrivsRequired: rootPath,
	})
	if !authResults.Allowed {
		retErr := authResults.Error
		if authResults.Error.ErrorOrNil() == nil || authResults.DeniedError {
			retErr = multierror.Append(retErr, logical.ErrPermissionDenied)
		}
		return auth, te, retErr
	}

	return auth, te, nil
}

// HandleRequest is used to handle a new incoming request
func (c *Core) HandleRequest(httpCtx context.Context, req *logical.Request) (resp *logical.Response, err error) {
	c.stateLock.RLock()
	defer c.stateLock.RUnlock()
	if c.Sealed() {
		return nil, consts.ErrSealed
	}
	if c.standby {
		return nil, consts.ErrStandby
	}

	ctx, cancel := context.WithCancel(c.activeContext)
	defer cancel()

	go func(ctx context.Context, httpCtx context.Context) {
		select {
		case <-ctx.Done():
		case <-httpCtx.Done():
			cancel()
		}
	}(ctx, httpCtx)

	// Allowing writing to a path ending in / makes it extremely difficult to
	// understand user intent for the filesystem-like backends (kv,
	// cubbyhole) -- did they want a key named foo/ or did they want to write
	// to a directory foo/ with no (or forgotten) key, or...? It also affects
	// lookup, because paths ending in / are considered prefixes by some
	// backends. Basically, it's all just terrible, so don't allow it.
	if strings.HasSuffix(req.Path, "/") &&
		(req.Operation == logical.UpdateOperation ||
			req.Operation == logical.CreateOperation) {
		return logical.ErrorResponse("cannot write to a path ending in '/'"), nil
	}

	var auth *logical.Auth
	if c.router.LoginPath(req.Path) {
		resp, auth, err = c.handleLoginRequest(ctx, req)
	} else {
		resp, auth, err = c.handleRequest(ctx, req)
	}

	// Ensure we don't leak internal data
	if resp != nil {
		if resp.Secret != nil {
			resp.Secret.InternalData = nil
		}
		if resp.Auth != nil {
			resp.Auth.InternalData = nil
		}
	}

	// We are wrapping if there is anything to wrap (not a nil response) and a
	// TTL was specified for the token. Errors on a call should be returned to
	// the caller, so wrapping is turned off if an error is hit and the error
	// is logged to the audit log.
	wrapping := resp != nil &&
		err == nil &&
		!resp.IsError() &&
		resp.WrapInfo != nil &&
		resp.WrapInfo.TTL != 0 &&
		resp.WrapInfo.Token == ""

	if wrapping {
		cubbyResp, cubbyErr := c.wrapInCubbyhole(ctx, req, resp, auth)
		// If not successful, returns either an error response from the
		// cubbyhole backend or an error; if either is set, set resp and err to
		// those and continue so that that's what we audit log. Otherwise
		// finish the wrapping and audit log that.
		if cubbyResp != nil || cubbyErr != nil {
			resp = cubbyResp
			err = cubbyErr
		} else {
			wrappingResp := &logical.Response{
				WrapInfo: resp.WrapInfo,
				Warnings: resp.Warnings,
			}
			resp = wrappingResp
		}
	}

	auditResp := resp
	// When unwrapping we want to log the actual response that will be written
	// out. We still want to return the raw value to avoid automatic updating
	// to any of it.
	if req.Path == "sys/wrapping/unwrap" &&
		resp != nil &&
		resp.Data != nil &&
		resp.Data[logical.HTTPRawBody] != nil {

		// Decode the JSON
		if resp.Data[logical.HTTPRawBodyAlreadyJSONDecoded] != nil {
			delete(resp.Data, logical.HTTPRawBodyAlreadyJSONDecoded)
		} else {
			httpResp := &logical.HTTPResponse{}
			err := jsonutil.DecodeJSON(resp.Data[logical.HTTPRawBody].([]byte), httpResp)
			if err != nil {
				c.logger.Error("failed to unmarshal wrapped HTTP response for audit logging", "error", err)
				return nil, ErrInternalError
			}

			auditResp = logical.HTTPResponseToLogicalResponse(httpResp)
		}
	}

	var nonHMACReqDataKeys []string
	var nonHMACRespDataKeys []string
	entry := c.router.MatchingMountEntry(req.Path)
	if entry != nil {
		// Get and set ignored HMAC'd value. Reset those back to empty afterwards.
		if rawVals, ok := entry.synthesizedConfigCache.Load("audit_non_hmac_request_keys"); ok {
			nonHMACReqDataKeys = rawVals.([]string)
		}

		// Get and set ignored HMAC'd value. Reset those back to empty afterwards.
		if auditResp != nil {
			if rawVals, ok := entry.synthesizedConfigCache.Load("audit_non_hmac_response_keys"); ok {
				nonHMACRespDataKeys = rawVals.([]string)
			}
		}
	}

	// Create an audit trail of the response
	logInput := &audit.LogInput{
		Auth:                auth,
		Request:             req,
		Response:            auditResp,
		OuterErr:            err,
		NonHMACReqDataKeys:  nonHMACReqDataKeys,
		NonHMACRespDataKeys: nonHMACRespDataKeys,
	}
	if auditErr := c.auditBroker.LogResponse(ctx, logInput, c.auditedHeaders); auditErr != nil {
		c.logger.Error("failed to audit response", "request_path", req.Path, "error", auditErr)
		return nil, ErrInternalError
	}

	return
}

func (c *Core) handleRequest(ctx context.Context, req *logical.Request) (retResp *logical.Response, retAuth *logical.Auth, retErr error) {
	defer metrics.MeasureSince([]string{"core", "handle_request"}, time.Now())

	var nonHMACReqDataKeys []string
	entry := c.router.MatchingMountEntry(req.Path)
	if entry != nil {
		// Get and set ignored HMAC'd value.
		if rawVals, ok := entry.synthesizedConfigCache.Load("audit_non_hmac_request_keys"); ok {
			nonHMACReqDataKeys = rawVals.([]string)
		}
	}

	// Validate the token
	auth, te, ctErr := c.checkToken(ctx, req, false)
	// We run this logic first because we want to decrement the use count even in the case of an error
	if te != nil {
		// Attempt to use the token (decrement NumUses)
		var err error
		te, err = c.tokenStore.UseToken(ctx, te)
		if err != nil {
			c.logger.Error("failed to use token", "error", err)
			retErr = multierror.Append(retErr, ErrInternalError)
			return nil, nil, retErr
		}
		if te == nil {
			// Token has been revoked by this point
			retErr = multierror.Append(retErr, logical.ErrPermissionDenied)
			return nil, nil, retErr
		}
		if te.NumUses == tokenRevocationPending {
			// We defer a revocation until after logic has run, since this is a
			// valid request (this is the token's final use). We pass the ID in
			// directly just to be safe in case something else modifies te later.
			defer func(id string) {
				leaseID, err := c.expiration.CreateOrFetchRevocationLeaseByToken(c.activeContext, te)
				if err == nil {
					err = c.expiration.LazyRevoke(ctx, leaseID)
				}
				if err != nil {
					c.logger.Error("failed to revoke token", "error", err)
					retResp = nil
					retAuth = nil
					retErr = multierror.Append(retErr, ErrInternalError)
				}
				if retResp != nil && retResp.Secret != nil &&
					// Some backends return a TTL even without a Lease ID
					retResp.Secret.LeaseID != "" {
					retResp = logical.ErrorResponse("Secret cannot be returned; token had one use left, so leased credentials were immediately revoked.")
					return
				}
			}(te.ID)
		}
	}
	if ctErr != nil {
		// If it is an internal error we return that, otherwise we
		// return invalid request so that the status codes can be correct
		switch {
		case ctErr == ErrInternalError,
			errwrap.Contains(ctErr, ErrInternalError.Error()),
			ctErr == logical.ErrPermissionDenied,
			errwrap.Contains(ctErr, logical.ErrPermissionDenied.Error()):
			switch ctErr.(type) {
			case *multierror.Error:
				retErr = ctErr
			default:
				retErr = multierror.Append(retErr, ctErr)
			}
		default:
			retErr = multierror.Append(retErr, logical.ErrInvalidRequest)
		}

		logInput := &audit.LogInput{
			Auth:               auth,
			Request:            req,
			OuterErr:           ctErr,
			NonHMACReqDataKeys: nonHMACReqDataKeys,
		}
		if err := c.auditBroker.LogRequest(ctx, logInput, c.auditedHeaders); err != nil {
			c.logger.Error("failed to audit request", "path", req.Path, "error", err)
		}

		if errwrap.Contains(retErr, ErrInternalError.Error()) {
			return nil, auth, retErr
		}
		return logical.ErrorResponse(ctErr.Error()), auth, retErr
	}

	// Attach the display name
	req.DisplayName = auth.DisplayName

	// Create an audit trail of the request
	logInput := &audit.LogInput{
		Auth:               auth,
		Request:            req,
		NonHMACReqDataKeys: nonHMACReqDataKeys,
	}
	if err := c.auditBroker.LogRequest(ctx, logInput, c.auditedHeaders); err != nil {
		c.logger.Error("failed to audit request", "path", req.Path, "error", err)
		retErr = multierror.Append(retErr, ErrInternalError)
		return nil, auth, retErr
	}

	// Route the request
	resp, routeErr := c.router.Route(ctx, req)
	if resp != nil {
		// If wrapping is used, use the shortest between the request and response
		var wrapTTL time.Duration
		var wrapFormat, creationPath string
		var sealWrap bool

		// Ensure no wrap info information is set other than, possibly, the TTL
		if resp.WrapInfo != nil {
			if resp.WrapInfo.TTL > 0 {
				wrapTTL = resp.WrapInfo.TTL
			}
			wrapFormat = resp.WrapInfo.Format
			creationPath = resp.WrapInfo.CreationPath
			sealWrap = resp.WrapInfo.SealWrap
			resp.WrapInfo = nil
		}

		if req.WrapInfo != nil {
			if req.WrapInfo.TTL > 0 {
				switch {
				case wrapTTL == 0:
					wrapTTL = req.WrapInfo.TTL
				case req.WrapInfo.TTL < wrapTTL:
					wrapTTL = req.WrapInfo.TTL
				}
			}
			// If the wrap format hasn't been set by the response, set it to
			// the request format
			if req.WrapInfo.Format != "" && wrapFormat == "" {
				wrapFormat = req.WrapInfo.Format
			}
		}

		if wrapTTL > 0 {
			resp.WrapInfo = &wrapping.ResponseWrapInfo{
				TTL:          wrapTTL,
				Format:       wrapFormat,
				CreationPath: creationPath,
				SealWrap:     sealWrap,
			}
		}
	}

	// If there is a secret, we must register it with the expiration manager.
	// We exclude renewal of a lease, since it does not need to be re-registered
	if resp != nil && resp.Secret != nil && !strings.HasPrefix(req.Path, "sys/renew") &&
		!strings.HasPrefix(req.Path, "sys/leases/renew") {
		// KV mounts should return the TTL but not register
		// for a lease as this provides a massive slowdown
		registerLease := true

		matchingMountEntry := c.router.MatchingMountEntry(req.Path)
		if matchingMountEntry == nil {
			c.logger.Error("unable to retrieve kv mount entry from router")
			retErr = multierror.Append(retErr, ErrInternalError)
			return nil, auth, retErr
		}

		switch matchingMountEntry.Type {
		case "kv", "generic":
			// If we are kv type, first see if we are an older passthrough
			// backend, and otherwise check the mount entry options.
			matchingBackend := c.router.MatchingBackend(req.Path)
			if matchingBackend == nil {
				c.logger.Error("unable to retrieve kv backend from router")
				retErr = multierror.Append(retErr, ErrInternalError)
				return nil, auth, retErr
			}

			if ptbe, ok := matchingBackend.(*PassthroughBackend); ok {
				if !ptbe.GeneratesLeases() {
					registerLease = false
					resp.Secret.Renewable = false
				}
			} else if matchingMountEntry.Options == nil || matchingMountEntry.Options["leased_passthrough"] != "true" {
				registerLease = false
				resp.Secret.Renewable = false
			}

		case "plugin":
			// If we are a plugin type and the plugin name is "kv" check the
			// mount entry options.
			if matchingMountEntry.Config.PluginName == "kv" && (matchingMountEntry.Options == nil || matchingMountEntry.Options["leased_passthrough"] != "true") {
				registerLease = false
				resp.Secret.Renewable = false
			}
		}

		if registerLease {
			sysView := c.router.MatchingSystemView(req.Path)
			if sysView == nil {
				c.logger.Error("unable to look up sys view for login path", "request_path", req.Path)
				return nil, nil, ErrInternalError
			}

			ttl, warnings, err := framework.CalculateTTL(sysView, 0, resp.Secret.TTL, 0, resp.Secret.MaxTTL, 0, time.Time{})
			if err != nil {
				return nil, nil, err
			}
			for _, warning := range warnings {
				resp.AddWarning(warning)
			}
			resp.Secret.TTL = ttl

			leaseID, err := c.expiration.Register(ctx, req, resp)
			if err != nil {
				c.logger.Error("failed to register lease", "request_path", req.Path, "error", err)
				retErr = multierror.Append(retErr, ErrInternalError)
				return nil, auth, retErr
			}
			resp.Secret.LeaseID = leaseID
		}
	}

	// Only the token store is allowed to return an auth block, for any
	// other request this is an internal error. We exclude renewal of a token,
	// since it does not need to be re-registered
	if resp != nil && resp.Auth != nil && !strings.HasPrefix(req.Path, "auth/token/renew") {
		if !strings.HasPrefix(req.Path, "auth/token/") {
			c.logger.Error("unexpected Auth response for non-token backend", "request_path", req.Path)
			retErr = multierror.Append(retErr, ErrInternalError)
			return nil, auth, retErr
		}

		_, identityPolicies, err := c.fetchEntityAndDerivedPolicies(resp.Auth.EntityID)
		if err != nil {
			c.tokenStore.revokeOrphan(ctx, te.ID)
			return nil, nil, ErrInternalError
		}

		resp.Auth.TokenPolicies = policyutil.SanitizePolicies(resp.Auth.Policies, policyutil.DoNotAddDefaultPolicy)
		if err := c.expiration.RegisterAuth(ctx, resp.Auth.CreationPath, resp.Auth); err != nil {
			c.tokenStore.revokeOrphan(ctx, te.ID)
			c.logger.Error("failed to register token lease", "request_path", req.Path, "error", err)
			retErr = multierror.Append(retErr, ErrInternalError)
			return nil, auth, retErr
		}

		// We do these later since it's not meaningful for backends/expmgr to
		// have what is purely a snapshot of current identity policies, and
		// plugins can be confused if they are checking contents of
		// Auth.Policies instead of Auth.TokenPolicies
		resp.Auth.IdentityPolicies = policyutil.SanitizePolicies(identityPolicies, policyutil.DoNotAddDefaultPolicy)
		resp.Auth.Policies = policyutil.SanitizePolicies(append(resp.Auth.Policies, identityPolicies...), policyutil.DoNotAddDefaultPolicy)
	}

	if resp != nil &&
		req.Path == "cubbyhole/response" &&
		len(te.Policies) == 1 &&
		te.Policies[0] == responseWrappingPolicyName {
		resp.AddWarning("Reading from 'cubbyhole/response' is deprecated. Please use sys/wrapping/unwrap to unwrap responses, as it provides additional security checks and other benefits.")
	}

	// Return the response and error
	if routeErr != nil {
		retErr = multierror.Append(retErr, routeErr)
	}

	return resp, auth, retErr
}

// handleLoginRequest is used to handle a login request, which is an
// unauthenticated request to the backend.
func (c *Core) handleLoginRequest(ctx context.Context, req *logical.Request) (retResp *logical.Response, retAuth *logical.Auth, retErr error) {
	defer metrics.MeasureSince([]string{"core", "handle_login_request"}, time.Now())

	req.Unauthenticated = true

	var auth *logical.Auth
	// Create an audit trail of the request, auth is not available on login requests
	// Create an audit trail of the request. Attach auth if it was returned,
	// e.g. if a token was provided.
	logInput := &audit.LogInput{
		Auth:    auth,
		Request: req,
	}
	if err := c.auditBroker.LogRequest(ctx, logInput, c.auditedHeaders); err != nil {
		c.logger.Error("failed to audit request", "path", req.Path, "error", err)
		return nil, nil, ErrInternalError
	}

	// The token store uses authentication even when creating a new token,
	// so it's handled in handleRequest. It should not be reached here.
	if strings.HasPrefix(req.Path, "auth/token/") {
		c.logger.Error("unexpected login request for token backend", "request_path", req.Path)
		return nil, nil, ErrInternalError
	}

	// Route the request
	resp, routeErr := c.router.Route(ctx, req)
	if resp != nil {
		// If wrapping is used, use the shortest between the request and response
		var wrapTTL time.Duration
		var wrapFormat, creationPath string
		var sealWrap bool

		// Ensure no wrap info information is set other than, possibly, the TTL
		if resp.WrapInfo != nil {
			if resp.WrapInfo.TTL > 0 {
				wrapTTL = resp.WrapInfo.TTL
			}
			wrapFormat = resp.WrapInfo.Format
			creationPath = resp.WrapInfo.CreationPath
			sealWrap = resp.WrapInfo.SealWrap
			resp.WrapInfo = nil
		}

		if req.WrapInfo != nil {
			if req.WrapInfo.TTL > 0 {
				switch {
				case wrapTTL == 0:
					wrapTTL = req.WrapInfo.TTL
				case req.WrapInfo.TTL < wrapTTL:
					wrapTTL = req.WrapInfo.TTL
				}
			}
			if req.WrapInfo.Format != "" && wrapFormat == "" {
				wrapFormat = req.WrapInfo.Format
			}
		}

		if wrapTTL > 0 {
			resp.WrapInfo = &wrapping.ResponseWrapInfo{
				TTL:          wrapTTL,
				Format:       wrapFormat,
				CreationPath: creationPath,
				SealWrap:     sealWrap,
			}
		}
	}

	// A login request should never return a secret!
	if resp != nil && resp.Secret != nil {
		c.logger.Error("unexpected Secret response for login path", "request_path", req.Path)
		return nil, nil, ErrInternalError
	}

	// If the response generated an authentication, then generate the token
	if resp != nil && resp.Auth != nil {

		var entity *identity.Entity
		auth = resp.Auth

		mEntry := c.router.MatchingMountEntry(req.Path)

		if auth.Alias != nil &&
			mEntry != nil &&
			!mEntry.Local &&
			c.identityStore != nil {
			// Overwrite the mount type and mount path in the alias
			// information
			auth.Alias.MountType = req.MountType
			auth.Alias.MountAccessor = req.MountAccessor

			if auth.Alias.Name == "" {
				return nil, nil, fmt.Errorf("missing name in alias")
			}

			var err error

			// Fetch the entity for the alias, or create an entity if one
			// doesn't exist.
			entity, err = c.identityStore.CreateOrFetchEntity(auth.Alias)
			if err != nil {
				return nil, nil, err
			}

			if entity == nil {
				return nil, nil, fmt.Errorf("failed to create an entity for the authenticated alias")
			}

			if entity.Disabled {
				return nil, nil, logical.ErrPermissionDenied
			}

			auth.EntityID = entity.ID
			if auth.GroupAliases != nil {
				validAliases, err := c.identityStore.refreshExternalGroupMembershipsByEntityID(auth.EntityID, auth.GroupAliases)
				if err != nil {
					return nil, nil, err
				}
				auth.GroupAliases = validAliases
			}
		}

		// Determine the source of the login
		source := c.router.MatchingMount(req.Path)
		source = strings.TrimPrefix(source, credentialRoutePrefix)
		source = strings.Replace(source, "/", "-", -1)

		// Prepend the source to the display name
		auth.DisplayName = strings.TrimSuffix(source+auth.DisplayName, "-")

		sysView := c.router.MatchingSystemView(req.Path)
		if sysView == nil {
			c.logger.Error("unable to look up sys view for login path", "request_path", req.Path)
			return nil, nil, ErrInternalError
		}

		tokenTTL, warnings, err := framework.CalculateTTL(sysView, 0, auth.TTL, auth.Period, auth.MaxTTL, auth.ExplicitMaxTTL, time.Time{})
		if err != nil {
			return nil, nil, err
		}
		for _, warning := range warnings {
			resp.AddWarning(warning)
		}

		// We first assign token policies to what was returned from the backend
		// via auth.Policies. Then, we get the full set of policies into
		// auth.Policies from the backend + entity information -- this is not
		// stored in the token, but we perform sanity checks on it and return
		// that information to the user.

		// Generate a token
		te := logical.TokenEntry{
			Path:         req.Path,
			Meta:         auth.Metadata,
			DisplayName:  auth.DisplayName,
			CreationTime: time.Now().Unix(),
			TTL:          tokenTTL,
			NumUses:      auth.NumUses,
			EntityID:     auth.EntityID,
			BoundCIDRs:   auth.BoundCIDRs,
		}

		te.Policies = policyutil.SanitizePolicies(auth.Policies, policyutil.AddDefaultPolicy)

		_, identityPolicies, err := c.fetchEntityAndDerivedPolicies(auth.EntityID)
		if err != nil {
			return nil, nil, ErrInternalError
		}

		auth.TokenPolicies = te.Policies
		allPolicies := policyutil.SanitizePolicies(append(te.Policies, identityPolicies...), policyutil.DoNotAddDefaultPolicy)

		// Prevent internal policies from being assigned to tokens. We check
		// this on auth.Policies including derived ones from Identity before
		// actually making the token.
		for _, policy := range allPolicies {
			if policy == "root" {
				return logical.ErrorResponse("auth methods cannot create root tokens"), nil, logical.ErrInvalidRequest
			}
			if strutil.StrListContains(nonAssignablePolicies, policy) {
				return logical.ErrorResponse(fmt.Sprintf("cannot assign policy %q", policy)), nil, logical.ErrInvalidRequest
			}
		}

		if err := c.tokenStore.create(ctx, &te); err != nil {
			c.logger.Error("failed to create token", "error", err)
			return nil, auth, ErrInternalError
		}

		// Populate the client token, accessor, and TTL
		auth.ClientToken = te.ID
		auth.Accessor = te.Accessor
		auth.TTL = te.TTL

		// Register with the expiration manager
		if err := c.expiration.RegisterAuth(ctx, te.Path, auth); err != nil {
			c.tokenStore.revokeOrphan(ctx, te.ID)
			c.logger.Error("failed to register token lease", "request_path", req.Path, "error", err)
			return nil, auth, ErrInternalError
		}

		auth.IdentityPolicies = policyutil.SanitizePolicies(identityPolicies, policyutil.DoNotAddDefaultPolicy)
		auth.Policies = allPolicies

		// Attach the display name, might be used by audit backends
		req.DisplayName = auth.DisplayName
	}

	return resp, auth, routeErr
}
