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package secretsengine
import (
"context"
"errors"
"fmt"
"time"
"git.tardisproject.uk/tcmal/vault-plugin-kerberos-secrets/config"
"git.tardisproject.uk/tcmal/vault-plugin-kerberos-secrets/password"
"github.com/hashicorp/vault/sdk/framework"
"github.com/hashicorp/vault/sdk/logical"
)
const (
rotateRootPath = "rotate-root"
rotateRolePath = "rotate-static-role/"
)
func pathRotateCredentials(b *krbBackend) []*framework.Path {
return []*framework.Path{
{
Pattern: rotateRootPath,
Fields: map[string]*framework.FieldSchema{},
Operations: map[logical.Operation]framework.OperationHandler{
logical.UpdateOperation: &framework.PathOperation{
Callback: b.pathRotateRootCredentialsUpdate,
ForwardPerformanceStandby: true,
ForwardPerformanceSecondary: true,
},
},
HelpSynopsis: "Request to rotate the root credentials Vault uses for the kerberos administrator account.",
HelpDescription: "This path attempts to rotate the root credentials of the administrator account " +
"used by Vault to manage credentials.",
},
{
Pattern: rotateRolePath + framework.GenericNameRegex("name"),
Fields: map[string]*framework.FieldSchema{
"name": {
Type: framework.TypeString,
Description: "Name of the static role",
},
},
Operations: map[logical.Operation]framework.OperationHandler{
logical.UpdateOperation: &framework.PathOperation{
Callback: b.pathRotateRoleCredentialsUpdate,
ForwardPerformanceStandby: true,
ForwardPerformanceSecondary: true,
},
},
HelpSynopsis: "Request to rotate the credentials for a static user account.",
HelpDescription: "This path attempts to rotate the credentials for the given static role.",
},
}
}
func (b *krbBackend) pathRotateRootCredentialsUpdate(ctx context.Context, req *logical.Request, data *framework.FieldData) (*logical.Response, error) {
if _, hasTimeout := ctx.Deadline(); !hasTimeout {
var cancel func()
ctx, cancel = context.WithTimeout(ctx, defaultCtxTimeout)
defer cancel()
}
config, err := getConfig(ctx, req.Storage)
if err != nil {
return nil, err
}
if config == nil {
return nil, errors.New("the config is currently unset")
}
client, err := b.getClient(ctx, req.Storage)
if err != nil {
return nil, err
}
newPassword := password.Generate()
// Update the password remotely.
if err := (*client).SetPassword(ctx, config.Username, newPassword); err != nil {
return nil, err
}
// Update the password locally.
config.Password = newPassword
if pwdStoringErr := storePassword(ctx, req.Storage, config); pwdStoringErr != nil {
return nil, fmt.Errorf("unable to update password due to storage err: %s", pwdStoringErr)
// TODO: deal with this more gracefully
}
b.reset()
// Respond with a 204.
return nil, nil
}
func (b *krbBackend) pathRotateRoleCredentialsUpdate(ctx context.Context, req *logical.Request, data *framework.FieldData) (*logical.Response, error) {
name := data.Get("name").(string)
if name == "" {
return logical.ErrorResponse("empty role name attribute given"), nil
}
role, err := b.getRole(ctx, req.Storage, name)
if err != nil {
return nil, fmt.Errorf("error fetching role from storage: %s", err)
}
if role == nil {
return nil, fmt.Errorf("role does not exist: %s", name)
}
b.backgroundRotation(name, req.Storage)
return nil, nil
}
func (b *krbBackend) backgroundRotation(name string, storage logical.Storage) {
// make sure we're not in the rotation list already, and add us if not.
// this ensures we dont have two credential rotations running for the same principal
// at the same time.
b.rotationListLock.Lock()
_, ok := b.rotationList[name]
if ok {
b.rotationListLock.Unlock()
b.Logger().With("role", name).Debug("rotation already in progress, not starting another one")
return
}
b.rotationList[name] = true
// done adding to list
b.rotationListLock.Unlock()
ictx, _ := context.WithTimeout(context.Background(), time.Minute*60)
go b.doRotation(ictx, name, storage)
}
func (b *krbBackend) doRotation(ctx context.Context, name string, storage logical.Storage) {
log := b.Logger().With("role", name)
log.Debug("starting to rotate role")
defer func() {
// remove from rotation list
b.rotationListLock.Lock()
if _, ok := b.rotationList[name]; ok {
delete(b.rotationList, name)
}
b.rotationListLock.Unlock()
}()
for {
err, retry := b.attemptRotation(ctx, name, storage) // TODO
if err == nil {
log.Debug("credentials rotated")
return
}
log.Error("error rotating credentials", "error", err)
if !retry {
log.Error("unrecoverable error rotating credentials")
}
timer := time.NewTimer(5 * time.Second)
select {
case <-timer.C:
continue
case <-ctx.Done():
log.Error("timeout rotating credentials")
return
}
}
}
func (b *krbBackend) attemptRotation(ctx context.Context, name string, storage logical.Storage) (error, bool) {
role, err := b.getRole(ctx, storage, name)
if err != nil {
return fmt.Errorf("error fetching role from storage: %s", err), true
}
if role == nil {
return fmt.Errorf("role does not exist: %s", name), false
}
c, err := b.getClient(ctx, storage)
if err != nil {
return fmt.Errorf("error getting client: %s", err), true
}
newPassword := password.Generate()
err = (*c).SetPassword(ctx, role.Principal, newPassword)
if err != nil {
return fmt.Errorf("error setting password: %s", err), true
}
role.Password = newPassword
role.LastVaultRotation = time.Now()
err = setRole(ctx, storage, name, role)
if err != nil {
return fmt.Errorf("rotated password but could not save back to storage"), true
// TODO: deal with this more gracefully
}
return nil, false
}
func storePassword(ctx context.Context, s logical.Storage, cfg *config.Config) error {
entry, err := logical.StorageEntryJSON(configStoragePath, cfg)
if err != nil {
return err
}
return s.Put(ctx, entry)
}
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