micro/auth/auth.go
2020-04-14 09:14:07 +01:00

144 lines
4.4 KiB
Go

// Package auth provides authentication and authorization capability
package auth
import (
"context"
"encoding/json"
"errors"
"time"
"github.com/micro/go-micro/v2/metadata"
)
var (
// ErrNotFound is returned when a resouce cannot be found
ErrNotFound = errors.New("not found")
// ErrEncodingToken is returned when the service encounters an error during encoding
ErrEncodingToken = errors.New("error encoding the token")
// ErrInvalidToken is returned when the token provided is not valid
ErrInvalidToken = errors.New("invalid token provided")
// ErrInvalidRole is returned when the role provided was invalid
ErrInvalidRole = errors.New("invalid role")
// ErrForbidden is returned when a user does not have the necessary roles to access a resource
ErrForbidden = errors.New("resource forbidden")
)
// Auth providers authentication and authorization
type Auth interface {
// Init the auth
Init(opts ...Option)
// Options set for auth
Options() Options
// Generate a new account
Generate(id string, opts ...GenerateOption) (*Account, error)
// Grant access to a resource
Grant(role string, res *Resource) error
// Revoke access to a resource
Revoke(role string, res *Resource) error
// Verify an account has access to a resource
Verify(acc *Account, res *Resource) error
// Inspect a token
Inspect(token string) (*Account, error)
// Token generated using refresh token
Token(opts ...TokenOption) (*Token, error)
// String returns the name of the implementation
String() string
}
// Resource is an entity such as a user or
type Resource struct {
// Name of the resource
Name string `json:"name"`
// Type of resource, e.g.
Type string `json:"type"`
// Endpoint resource e.g NotesService.Create
Endpoint string `json:"endpoint"`
// Namespace the resource belongs to
Namespace string `json:"namespace"`
}
// Account provided by an auth provider
type Account struct {
// ID of the account e.g. email
ID string `json:"id"`
// Type of the account, e.g. service
Type string `json:"type"`
// Provider who issued the account
Provider string `json:"provider"`
// Roles associated with the Account
Roles []string `json:"roles"`
// Any other associated metadata
Metadata map[string]string `json:"metadata"`
// Namespace the account belongs to
Namespace string `json:"namespace"`
// Secret for the account, e.g. the password
Secret string `json:"secret"`
}
// Token can be short or long lived
type Token struct {
// The token to be used for accessing resources
AccessToken string `json:"access_token"`
// RefreshToken to be used to generate a new token
RefreshToken string `json:"refresh_token"`
// Time of token creation
Created time.Time `json:"created"`
// Time of token expiry
Expiry time.Time `json:"expiry"`
}
const (
// DefaultNamespace used for auth
DefaultNamespace = "go.micro"
// NamespaceKey is the key used when storing the namespace in metadata
NamespaceKey = "Micro-Namespace"
// MetadataKey is the key used when storing the account in metadata
MetadataKey = "auth-account"
// TokenCookieName is the name of the cookie which stores the auth token
TokenCookieName = "micro-token"
// SecretCookieName is the name of the cookie which stores the auth secret
SecretCookieName = "micro-secret"
// BearerScheme used for Authorization header
BearerScheme = "Bearer "
)
// AccountFromContext gets the account from the context, which
// is set by the auth wrapper at the start of a call. If the account
// is not set, a nil account will be returned. The error is only returned
// when there was a problem retrieving an account
func AccountFromContext(ctx context.Context) (*Account, error) {
str, ok := metadata.Get(ctx, MetadataKey)
// there was no account set
if !ok {
return nil, nil
}
var acc *Account
// metadata is stored as a string, so unmarshal to an account
if err := json.Unmarshal([]byte(str), &acc); err != nil {
return nil, err
}
return acc, nil
}
// ContextWithAccount sets the account in the context
func ContextWithAccount(ctx context.Context, account *Account) (context.Context, error) {
// metadata is stored as a string, so marshal to bytes
bytes, err := json.Marshal(account)
if err != nil {
return ctx, err
}
// generate a new context with the MetadataKey set
return metadata.Set(ctx, MetadataKey, string(bytes)), nil
}
// NamespaceFromContext gets the namespace from the context
func NamespaceFromContext(ctx context.Context) string {
if ns, ok := metadata.Get(ctx, NamespaceKey); ok {
return ns
}
return DefaultNamespace
}