initial public commit

tools/auth/github.go

@@ -0,0 +1,87 @@
+package auth
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"strconv"
+
+	"golang.org/x/oauth2"
+)
+
+var _ Provider = (*Github)(nil)
+
+// NameGithub is the unique name of the Github provider.
+const NameGithub string = "github"
+
+// Github allows authentication via Github OAuth2.
+type Github struct {
+	*baseProvider
+}
+
+// NewGithubProvider creates new Github provider instance with some defaults.
+func NewGithubProvider() *Github {
+	return &Github{&baseProvider{
+		scopes:     []string{"user"},
+		authUrl:    "https://github.com/login/oauth/authorize",
+		tokenUrl:   "https://github.com/login/oauth/access_token",
+		userApiUrl: "https://api.github.com/user",
+	}}
+}
+
+// FetchAuthUser returns an AuthUser instance based the Github's user api.
+func (p *Github) FetchAuthUser(token *oauth2.Token) (*AuthUser, error) {
+	// https://docs.github.com/en/rest/reference/users#get-the-authenticated-user
+	rawData := struct {
+		Id        int    `json:"id"`
+		Name      string `json:"name"`
+		Email     string `json:"email"`
+		AvatarUrl string `json:"avatar_url"`
+	}{}
+
+	if err := p.FetchRawUserData(token, &rawData); err != nil {
+		return nil, err
+	}
+
+	user := &AuthUser{
+		Id:        strconv.Itoa(rawData.Id),
+		Name:      rawData.Name,
+		Email:     rawData.Email,
+		AvatarUrl: rawData.AvatarUrl,
+	}
+
+	// in case user set "Keep my email address private",
+	// email should be retrieved via extra API request
+	if user.Email == "" {
+		client := p.Client(token)
+
+		response, err := client.Get(p.userApiUrl + "/emails")
+		if err != nil {
+			return user, err
+		}
+		defer response.Body.Close()
+
+		content, err := ioutil.ReadAll(response.Body)
+		if err != nil {
+			return user, err
+		}
+
+		emails := []struct {
+			Email    string
+			Verified bool
+			Primary  bool
+		}{}
+		if err := json.Unmarshal(content, &emails); err != nil {
+			return user, err
+		}
+
+		// extract the verified primary email
+		for _, email := range emails {
+			if email.Verified && email.Primary {
+				user.Email = email.Email
+				break
+			}
+		}
+	}
+
+	return user, nil
+}