go get -u github.com/nilorg/oauth2

import "github.com/nilorg/oauth2"

package main

import (
    "fmt"
    "net/http"

    "github.com/gin-gonic/gin"
    "github.com/nilorg/oauth2"
)

var (
    clients = map[string]string{
        "oauth2_client": "password",
    }
)

func main() {
    srv := oauth2.NewServer()
    srv.VerifyClient = func(basic *oauth2.ClientBasic) (err error) {
        pwd, ok := clients[basic.ID]
        if !ok {
            err = oauth2.ErrInvalidClient
            return
        }
        basic = &oauth2.ClientBasic{
            ID:     basic.ID,
            Secret: pwd,
        }
        return
    }
    srv.VerifyClientID = func(clientID string) (err error) {
        _, ok := clients[clientID]
        if !ok {
        err = oath2.ErrInvalidClient
        }
        return
    }
    srv.VerifyCode = func(code, clientID, redirectURI string) (value *oauth2.CodeValue, err error) {
        //err = oauth2.ErrUnauthorizedClient
        // 查询缓存/数据库中的code信息
        value = &oauth2.CodeValue{
            ClientID:    clientID,
            RedirectURI: redirectURI,
            Scope:       []string{"a", "b", "c"},
        }
        return
    }
    srv.GenerateCode = func(clientID, openID, redirectURI string, scope []string) (code string, err error) {
        code = oauth2.RandomCode()
        return
    }}
    srv.VerifyRedirectURI = func(clientID, redirectURI string) (err error) {
        fmt.Println(clientID)
        fmt.Println(redirectURI)
        // err = oauth2.ErrInvalidRedirectURI
        return
    }

    srv.VerifyPassword = func(username, password string) (openID string, err error) {
        if username != "a" || password != "b" {
            err = oauth2.ErrUnauthorizedClient
            return
        }
        openID = "xxxx"
        return
    }

    srv.VerifyScope = func(scopes []string, clientID string) (err error) {
        // err = oauth2.ErrInvalidScope
        return
    }

    srv.GenerateAccessToken = oauth2.NewDefaultGenerateAccessToken([]byte("xxxxx"))
    srv.RefreshAccessToken = oauth2.NewDefaultRefreshAccessToken([]byte("xxxxx"))
    srv.ParseAccessToken = oauth2.NewDefaultParseAccessToken([]byte("xxxxx"))

    srv.GenerateDeviceAuthorization = func(issuer, verificationURI, clientID, scope string) (resp *oauth2.DeviceAuthorizationResponse, err error) {
        resp = &oauth2.DeviceAuthorizationResponse{
            DeviceCode:            oauth2.RandomCode(),
            UserCode:              oauth2.RandomUserCode(),
            VerificationURI:       verificationURI,
            VerificationURIQrcode: "",
            ExpiresIn:             0,
            Interval: