initial public commit

tools/auth/auth.go

@@ -0,0 +1,96 @@
+package auth
+
+import (
+	"errors"
+	"net/http"
+
+	"golang.org/x/oauth2"
+)
+
+// AuthUser defines a standardized oauth2 user data structure.
+type AuthUser struct {
+	Id        string `json:"id"`
+	Name      string `json:"name"`
+	Email     string `json:"email"`
+	AvatarUrl string `json:"avatarUrl"`
+}
+
+// Provider defines a common interface for an OAuth2 client.
+type Provider interface {
+	// Scopes returns the provider access permissions that will be requested.
+	Scopes() []string
+
+	// SetScopes sets the provider access permissions that will be requested later.
+	SetScopes(scopes []string)
+
+	// ClientId returns the provider client's app ID.
+	ClientId() string
+
+	// SetClientId sets the provider client's ID.
+	SetClientId(clientId string)
+
+	// ClientId returns the provider client's app secret.
+	ClientSecret() string
+
+	// SetClientSecret sets the provider client's app secret.
+	SetClientSecret(secret string)
+
+	// RedirectUrl returns the end address to redirect the user
+	// going through the OAuth flow.
+	RedirectUrl() string
+
+	// SetRedirectUrl sets the provider's RedirectUrl.
+	SetRedirectUrl(url string)
+
+	// AuthUrl returns the provider's authorization service url.
+	AuthUrl() string
+
+	// SetAuthUrl sets the provider's AuthUrl.
+	SetAuthUrl(url string)
+
+	// TokenUrl returns the provider's token exchange service url.
+	TokenUrl() string
+
+	// SetTokenUrl sets the provider's TokenUrl.
+	SetTokenUrl(url string)
+
+	// UserApiUrl returns the provider's user info api url.
+	UserApiUrl() string
+
+	// SetUserApiUrl sets the provider's UserApiUrl.
+	SetUserApiUrl(url string)
+
+	// Client returns an http client using the provided token.
+	Client(token *oauth2.Token) *http.Client
+
+	// BuildAuthUrl returns a URL to the provider's consent page
+	// that asks for permissions for the required scopes explicitly.
+	BuildAuthUrl(state string, opts ...oauth2.AuthCodeOption) string
+
+	// FetchToken converts an authorization code to token.
+	FetchToken(code string, opts ...oauth2.AuthCodeOption) (*oauth2.Token, error)
+
+	// FetchRawUserData requests and marshalizes into `result` the
+	// the OAuth user api response.
+	FetchRawUserData(token *oauth2.Token, result any) error
+
+	// FetchAuthUser is similar to FetchRawUserData, but normalizes and
+	// marshalizes the user api response into a standardized AuthUser struct.
+	FetchAuthUser(token *oauth2.Token) (user *AuthUser, err error)
+}
+
+// NewProviderByName returns a new preconfigured provider instance by its name identifier.
+func NewProviderByName(name string) (Provider, error) {
+	switch name {
+	case NameGoogle:
+		return NewGoogleProvider(), nil
+	case NameFacebook:
+		return NewFacebookProvider(), nil
+	case NameGithub:
+		return NewGithubProvider(), nil
+	case NameGitlab:
+		return NewGitlabProvider(), nil
+	default:
+		return nil, errors.New("Missing provider " + name)
+	}
+}