feat: Implement Steam login initialization logic

- Added SteamLoginInitLogic to handle the initiation of Steam login.
- Created service context for managing configuration and Redis connection.
- Defined types for Steam login requests and callbacks.
- Implemented utility functions for building OpenID query strings and validating responses from Steam.
- Updated go.mod and go.sum to include necessary dependencies.
- Modified GenApi.ps1 script to generate code in the correct directory.

app/internal/config/config.go

@@ -0,0 +1,24 @@
+package config
+
+import (
+	"github.com/zeromicro/go-zero/core/stores/redis"
+	"github.com/zeromicro/go-zero/rest"
+)
+
+type Config struct {
+	rest.RestConf
+	Steam SteamConfig
+	JWT   JWTConfig
+	Redis redis.RedisConf
+}
+
+type SteamConfig struct {
+	CallbackURL         string
+	FrontendCallbackURL string
+}
+
+type JWTConfig struct {
+	Secret    string
+	Issuer    string
+	ExpiresIn int64
+}

app/internal/handler/pinghandler.go

@@ -0,0 +1,29 @@
+package handler
+
+import (
+	"net/http"
+
+	"git.cialloo.com/CiallooWeb/Authenticator/app/internal/logic"
+	"git.cialloo.com/CiallooWeb/Authenticator/app/internal/svc"
+	"git.cialloo.com/CiallooWeb/Authenticator/app/internal/types"
+	"github.com/zeromicro/go-zero/rest/httpx"
+)
+
+// Ping the server to check if it's alive
+func pingHandler(svcCtx *svc.ServiceContext) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		var req types.PingReq
+		if err := httpx.Parse(r, &req); err != nil {
+			httpx.ErrorCtx(r.Context(), w, err)
+			return
+		}
+
+		l := logic.NewPingLogic(r.Context(), svcCtx)
+		resp, err := l.Ping(&req)
+		if err != nil {
+			httpx.ErrorCtx(r.Context(), w, err)
+		} else {
+			httpx.OkJsonCtx(r.Context(), w, resp)
+		}
+	}
+}

app/internal/handler/routes.go

@@ -0,0 +1,38 @@
+// Code generated by goctl. DO NOT EDIT.
+// goctl 1.8.4
+
+package handler
+
+import (
+	"net/http"
+
+	"git.cialloo.com/CiallooWeb/Authenticator/app/internal/svc"
+
+	"github.com/zeromicro/go-zero/rest"
+)
+
+func RegisterHandlers(server *rest.Server, serverCtx *svc.ServiceContext) {
+	server.AddRoutes(
+		[]rest.Route{
+			{
+				// Ping the server to check if it's alive
+				Method:  http.MethodGet,
+				Path:    "/ping",
+				Handler: pingHandler(serverCtx),
+			},
+			{
+				// Steam login callback
+				Method:  http.MethodGet,
+				Path:    "/steam/callback",
+				Handler: steamLoginCallbackHandler(serverCtx),
+			},
+			{
+				// Initiate Steam login
+				Method:  http.MethodGet,
+				Path:    "/steam/login",
+				Handler: steamLoginInitHandler(serverCtx),
+			},
+		},
+		rest.WithPrefix("/api/authenticator"),
+	)
+}

app/internal/handler/steamlogincallbackhandler.go

@@ -0,0 +1,29 @@
+package handler
+
+import (
+	"net/http"
+
+	"git.cialloo.com/CiallooWeb/Authenticator/app/internal/logic"
+	"git.cialloo.com/CiallooWeb/Authenticator/app/internal/svc"
+	"git.cialloo.com/CiallooWeb/Authenticator/app/internal/types"
+
+	"github.com/zeromicro/go-zero/rest/httpx"
+)
+
+// Steam login callback
+func steamLoginCallbackHandler(svcCtx *svc.ServiceContext) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		var req types.SteamLoginCallbackReq
+		if err := httpx.Parse(r, &req); err != nil {
+			httpx.ErrorCtx(r.Context(), w, err)
+			return
+		}
+
+		l := logic.NewSteamLoginCallbackLogic(r.Context(), svcCtx)
+		err := l.SteamLoginCallback(&req, w, r)
+		if err != nil {
+			httpx.ErrorCtx(r.Context(), w, err)
+		}
+		// No response needed - redirect is handled in logic
+	}
+}

app/internal/handler/steamlogininithandler.go

@@ -0,0 +1,29 @@
+package handler
+
+import (
+	"net/http"
+
+	"git.cialloo.com/CiallooWeb/Authenticator/app/internal/logic"
+	"git.cialloo.com/CiallooWeb/Authenticator/app/internal/svc"
+	"git.cialloo.com/CiallooWeb/Authenticator/app/internal/types"
+
+	"github.com/zeromicro/go-zero/rest/httpx"
+)
+
+// Initiate Steam login
+func steamLoginInitHandler(svcCtx *svc.ServiceContext) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		var req types.SteamLoginInitReq
+		if err := httpx.Parse(r, &req); err != nil {
+			httpx.ErrorCtx(r.Context(), w, err)
+			return
+		}
+
+		l := logic.NewSteamLoginInitLogic(r.Context(), svcCtx)
+		err := l.SteamLoginInit(&req, w, r)
+		if err != nil {
+			httpx.ErrorCtx(r.Context(), w, err)
+		}
+		// No response needed - redirect is handled in logic
+	}
+}

app/internal/logic/pinglogic.go

@@ -0,0 +1,31 @@
+package logic
+
+import (
+	"context"
+
+	"git.cialloo.com/CiallooWeb/Authenticator/app/internal/svc"
+	"git.cialloo.com/CiallooWeb/Authenticator/app/internal/types"
+
+	"github.com/zeromicro/go-zero/core/logx"
+)
+
+type PingLogic struct {
+	logx.Logger
+	ctx    context.Context
+	svcCtx *svc.ServiceContext
+}
+
+// Ping the server to check if it's alive
+func NewPingLogic(ctx context.Context, svcCtx *svc.ServiceContext) *PingLogic {
+	return &PingLogic{
+		Logger: logx.WithContext(ctx),
+		ctx:    ctx,
+		svcCtx: svcCtx,
+	}
+}
+
+func (l *PingLogic) Ping(req *types.PingReq) (resp *types.PingResp, err error) {
+	// todo: add your logic here and delete this line
+
+	return
+}

app/internal/logic/steamlogincallbacklogic.go

@@ -0,0 +1,151 @@
+package logic
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"net/url"
+	"time"
+
+	"git.cialloo.com/CiallooWeb/Authenticator/app/internal/svc"
+	"git.cialloo.com/CiallooWeb/Authenticator/app/internal/types"
+	"git.cialloo.com/CiallooWeb/Authenticator/app/internal/utils/steamauth"
+
+	"github.com/golang-jwt/jwt/v4"
+	"github.com/zeromicro/go-zero/core/logx"
+)
+
+type SteamLoginCallbackLogic struct {
+	logx.Logger
+	ctx    context.Context
+	svcCtx *svc.ServiceContext
+}
+
+// JWT Claims structure
+type SteamJWTClaims struct {
+	SteamID string `json:"steamId"`
+	jwt.RegisteredClaims
+}
+
+// Steam login callback
+func NewSteamLoginCallbackLogic(ctx context.Context, svcCtx *svc.ServiceContext) *SteamLoginCallbackLogic {
+	return &SteamLoginCallbackLogic{
+		Logger: logx.WithContext(ctx),
+		ctx:    ctx,
+		svcCtx: svcCtx,
+	}
+}
+
+func (l *SteamLoginCallbackLogic) SteamLoginCallback(req *types.SteamLoginCallbackReq, w http.ResponseWriter, r *http.Request) error {
+	// Get the frontend callback URL from config
+	frontendCallbackURL := l.svcCtx.Config.Steam.FrontendCallbackURL
+
+	// Extract nonce from query parameter
+	nonce := r.URL.Query().Get("nonce")
+	if nonce == "" {
+		l.Logger.Errorf("Missing nonce in callback request")
+		redirectURL := fmt.Sprintf("%s?status=error&message=%s", frontendCallbackURL, url.QueryEscape("Invalid login session"))
+		http.Redirect(w, r, redirectURL, http.StatusFound)
+		return nil
+	}
+
+	// Validate nonce exists in Redis
+	nonceKey := nonceKeyPrefix + nonce
+	exists, err := l.svcCtx.Redis.Exists(nonceKey)
+	if err != nil {
+		l.Logger.Errorf("Failed to check nonce in Redis: %v", err)
+		redirectURL := fmt.Sprintf("%s?status=error&message=%s", frontendCallbackURL, url.QueryEscape("Session validation failed"))
+		http.Redirect(w, r, redirectURL, http.StatusFound)
+		return nil
+	}
+
+	if !exists {
+		l.Logger.Errorf("Invalid or expired nonce: %s", nonce)
+		redirectURL := fmt.Sprintf("%s?status=error&message=%s", frontendCallbackURL, url.QueryEscape("Login session expired or invalid"))
+		http.Redirect(w, r, redirectURL, http.StatusFound)
+		return nil
+	}
+
+	// Delete nonce from Redis to prevent replay attacks
+	_, err = l.svcCtx.Redis.Del(nonceKey)
+	if err != nil {
+		l.Logger.Errorf("Failed to delete nonce from Redis: %v", err)
+		// Continue anyway - nonce will expire naturally
+	}
+
+	// Convert the request to a map for validation
+	openidParams := map[string]string{
+		"openid.mode":           req.OpenidMode,
+		"openid.ns":             req.OpenidNs,
+		"openid.op_endpoint":    req.OpenidOpEndpoint,
+		"openid.claimed_id":     req.OpenidClaimedId,
+		"openid.identity":       req.OpenidIdentity,
+		"openid.return_to":      req.OpenidReturnTo,
+		"openid.response_nonce": req.OpenidResponseNonce,
+		"openid.assoc_handle":   req.OpenidAssocHandle,
+		"openid.signed":         req.OpenidSigned,
+		"openid.sig":            req.OpenidSig,
+	}
+
+	// Validate the Steam OpenID response
+	steamID, isValid, err := steamauth.ValidateResponse(openidParams)
+	if err != nil {
+		l.Logger.Errorf("Failed to validate Steam OpenID response: %v", err)
+		// Redirect to frontend with error status
+		redirectURL := fmt.Sprintf("%s?status=error&message=%s", frontendCallbackURL, url.QueryEscape("Failed to validate Steam response"))
+		http.Redirect(w, r, redirectURL, http.StatusFound)
+		return nil
+	}
+
+	if !isValid {
+		l.Logger.Errorf("Invalid Steam OpenID response")
+		// Redirect to frontend with failure status
+		redirectURL := fmt.Sprintf("%s?status=failed&message=%s", frontendCallbackURL, url.QueryEscape("Steam authentication failed"))
+		http.Redirect(w, r, redirectURL, http.StatusFound)
+		return nil
+	}
+
+	// Successful validation
+	l.Logger.Infof("Steam login successful for Steam ID: %s (nonce: %s)", steamID, nonce)
+
+	// Generate JWT token
+	token, err := l.generateJWT(steamID)
+	if err != nil {
+		l.Logger.Errorf("Failed to generate JWT token: %v", err)
+		redirectURL := fmt.Sprintf("%s?status=error&message=%s", frontendCallbackURL, url.QueryEscape("Failed to generate authentication token"))
+		http.Redirect(w, r, redirectURL, http.StatusFound)
+		return nil
+	}
+
+	// Redirect to frontend with success status, Steam ID, and JWT token
+	redirectURL := fmt.Sprintf("%s?status=success&steamId=%s&token=%s", frontendCallbackURL, steamID, token)
+	http.Redirect(w, r, redirectURL, http.StatusFound)
+
+	return nil
+}
+
+// generateJWT creates a JWT token for the authenticated user
+func (l *SteamLoginCallbackLogic) generateJWT(steamID string) (string, error) {
+	// Create claims
+	claims := SteamJWTClaims{
+		SteamID: steamID,
+		RegisteredClaims: jwt.RegisteredClaims{
+			ExpiresAt: jwt.NewNumericDate(time.Now().Add(time.Duration(l.svcCtx.Config.JWT.ExpiresIn) * time.Second)),
+			IssuedAt:  jwt.NewNumericDate(time.Now()),
+			NotBefore: jwt.NewNumericDate(time.Now()),
+			Issuer:    l.svcCtx.Config.JWT.Issuer,
+			Subject:   steamID,
+		},
+	}
+
+	// Create token
+	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
+
+	// Sign token with secret
+	tokenString, err := token.SignedString([]byte(l.svcCtx.Config.JWT.Secret))
+	if err != nil {
+		return "", err
+	}
+
+	return tokenString, nil
+}

app/internal/logic/steamlogininitlogic.go

@@ -0,0 +1,66 @@
+package logic
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"time"
+
+	"git.cialloo.com/CiallooWeb/Authenticator/app/internal/svc"
+	"git.cialloo.com/CiallooWeb/Authenticator/app/internal/types"
+	"git.cialloo.com/CiallooWeb/Authenticator/app/internal/utils/steamauth"
+
+	"github.com/google/uuid"
+	"github.com/zeromicro/go-zero/core/logx"
+)
+
+type SteamLoginInitLogic struct {
+	logx.Logger
+	ctx    context.Context
+	svcCtx *svc.ServiceContext
+}
+
+const (
+	// Redis key prefix for storing nonces
+	nonceKeyPrefix = "steam:nonce:"
+	// Nonce expiration time (5 minutes)
+	nonceExpiration = 5 * time.Minute
+)
+
+// Initiate Steam login
+func NewSteamLoginInitLogic(ctx context.Context, svcCtx *svc.ServiceContext) *SteamLoginInitLogic {
+	return &SteamLoginInitLogic{
+		Logger: logx.WithContext(ctx),
+		ctx:    ctx,
+		svcCtx: svcCtx,
+	}
+}
+
+func (l *SteamLoginInitLogic) SteamLoginInit(req *types.SteamLoginInitReq, w http.ResponseWriter, r *http.Request) error {
+	// Generate a unique nonce (UUID) for this login attempt
+	nonce := uuid.New().String()
+
+	// Store the nonce in Redis with expiration
+	nonceKey := nonceKeyPrefix + nonce
+	err := l.svcCtx.Redis.Setex(nonceKey, "1", int(nonceExpiration.Seconds()))
+	if err != nil {
+		l.Logger.Errorf("Failed to store nonce in Redis: %v", err)
+		return fmt.Errorf("failed to initialize login session")
+	}
+
+	// Get the callback URL from config
+	callbackURL := l.svcCtx.Config.Steam.CallbackURL
+
+	// Append nonce to callback URL for validation later
+	callbackURLWithNonce := fmt.Sprintf("%s?nonce=%s", callbackURL, nonce)
+
+	// Build the Steam OpenID redirect URL
+	redirectURL := steamauth.GetRedirectURL(callbackURLWithNonce)
+
+	l.Logger.Infof("Initiating Steam login with nonce: %s, callback URL: %s", nonce, callbackURL)
+
+	// Redirect user directly to Steam
+	http.Redirect(w, r, redirectURL, http.StatusFound)
+
+	return nil
+}

app/internal/svc/servicecontext.go

@@ -0,0 +1,19 @@
+package svc
+
+import (
+	"git.cialloo.com/CiallooWeb/Authenticator/app/internal/config"
+
+	"github.com/zeromicro/go-zero/core/stores/redis"
+)
+
+type ServiceContext struct {
+	Config config.Config
+	Redis  *redis.Redis
+}
+
+func NewServiceContext(c config.Config) *ServiceContext {
+	return &ServiceContext{
+		Config: c,
+		Redis:  redis.MustNewRedis(c.Redis),
+	}
+}

app/internal/types/types.go

@@ -0,0 +1,27 @@
+// Code generated by goctl. DO NOT EDIT.
+// goctl 1.8.4
+
+package types
+
+type PingReq struct {
+}
+
+type PingResp struct {
+	Ok bool `json:"ok"`
+}
+
+type SteamLoginCallbackReq struct {
+	OpenidMode          string `form:"openid.mode"`
+	OpenidNs            string `form:"openid.ns"`
+	OpenidOpEndpoint    string `form:"openid.op_endpoint"`
+	OpenidClaimedId     string `form:"openid.claimed_id"`
+	OpenidIdentity      string `form:"openid.identity"`
+	OpenidReturnTo      string `form:"openid.return_to"`
+	OpenidResponseNonce string `form:"openid.response_nonce"`
+	OpenidAssocHandle   string `form:"openid.assoc_handle"`
+	OpenidSigned        string `form:"openid.signed"`
+	OpenidSig           string `form:"openid.sig"`
+}
+
+type SteamLoginInitReq struct {
+}

app/internal/utils/steamauth/steamopenid.go

@@ -0,0 +1,148 @@
+package steamauth
+
+import (
+	"fmt"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"net/url"
+	"regexp"
+	"strings"
+	"time"
+)
+
+var validCredRx *regexp.Regexp
+var steamRx *regexp.Regexp
+var provider string = "https://steamcommunity.com/openid/login"
+
+func init() {
+	validCredRx = regexp.MustCompile("is_valid:true")
+	steamRx = regexp.MustCompile(`https://steamcommunity\.com/openid/id/(\d+)`)
+}
+
+// StringMapToString is a utility function that aims to efficiently build a query string
+// with a tiny footprint. theMap is expected to be a map of key strings with a value type of a string.
+func StringMapToString(theMap map[string]string) string {
+
+	mapLength := len(theMap)
+	strSeparator := "&"
+	i := 1
+
+	var builder strings.Builder
+	builder.Grow(66) // We already roughly know our base size.
+
+	for k, v := range theMap {
+
+		if i == mapLength {
+			strSeparator = ""
+		}
+
+		i++
+
+		fmt.Fprintf(&builder, "%s=%s%s", k, url.QueryEscape(v), strSeparator)
+	}
+
+	return builder.String()
+}
+
+// BuildQueryString is more or less building up a query string to be passed when reaching
+// Steam's openid 2.0 provider (or technically any openid 2.0 provider). We only care
+// that the Scheme is either http or https. Any other validation should really be done
+// before using this function.
+func BuildQueryString(responsePath string) string {
+
+	if responsePath[0:4] != "http" {
+		log.Fatal("http was not found in the responsePath!")
+	}
+
+	if responsePath[4:5] != "s" {
+		log.Println("https isn't being used! Is this intentional?")
+	}
+
+	// Even though the below URLs no longer function, the oauth 2.0 process formally calls
+	// for them and Valve actively checks for their presence.
+	openIdParameters := map[string]string{
+		"openid.mode":       "checkid_setup",
+		"openid.return_to":  responsePath,
+		"openid.realm":      responsePath,
+		"openid.ns":         "http://specs.openid.net/auth/2.0",
+		"openid.identity":   "http://specs.openid.net/auth/2.0/identifier_select",
+		"openid.claimed_id": "http://specs.openid.net/auth/2.0/identifier_select",
+	}
+
+	return StringMapToString(openIdParameters)
+}
+
+// ValidateResponse is the real chunk of work that goes on. When the client comes back to our site
+// we need to take what they give us in the query string and hit up the openid 2.0 provider directly
+// to verify what we're being provided with is well, valid.
+// If we end up with "is_valid:true" response from the Steam then isValid will always return true.
+// In any other situation (credential failure, error etc) isValid will always return false.
+// Takes a map[string]string to be agnostic among various http clients that exist out there
+func ValidateResponse(results map[string]string) (steamID64 string, isValid bool, err error) {
+
+	openIdValidation := map[string]string{
+		"openid.assoc_handle": results["openid.assoc_handle"],
+		"openid.signed":       results["openid.signed"],
+		"openid.sig":          results["openid.sig"],
+		"openid.ns":           results["openid.ns"],
+		"openid.mode":         "check_authentication",
+	}
+
+	signedParams := strings.Split(results["openid.signed"], ",")
+
+	for _, value := range signedParams {
+		item := fmt.Sprintf("openid.%s", value)
+		if _, exists := openIdValidation[item]; !exists {
+			openIdValidation[item] = results[item]
+		}
+	}
+
+	urlObj, err := url.Parse(provider)
+	if err != nil {
+		return "", false, err
+	}
+
+	urlObj.RawQuery = StringMapToString(openIdValidation)
+
+	httpClient := &http.Client{
+		Timeout: 10 * time.Second,
+	}
+
+	validationResp, err := httpClient.Get(urlObj.String())
+	if err != nil {
+		log.Printf("Failed to validate %s. Error: %s ", results["openid.claimed_id"], err)
+		return "", false, err
+	}
+
+	defer validationResp.Body.Close()
+	returnedBytes, err := ioutil.ReadAll(validationResp.Body)
+	if err != nil {
+		return "", false, err
+	}
+
+	if validCredRx.MatchString(string(returnedBytes)) == true {
+		return steamRx.FindStringSubmatch(results["openid.claimed_id"])[1], true, nil
+	}
+
+	return "", false, nil
+}
+
+// GetRedirectURL builds the Steam OpenID redirect URL
+func GetRedirectURL(callbackURL string) string {
+	urlObj, _ := url.Parse(provider)
+	urlObj.RawQuery = BuildQueryString(callbackURL)
+	return urlObj.String()
+}
+
+// ValuesToMap is a boilerplate function designed to convert the results of a url.Values
+// in to a readable map[string]string for ValidateResponse.
+// We don't get duplicate query keys supplied normally - but we'll always take the first one anyways
+func ValuesToMap(fakeMap url.Values) map[string]string {
+	returnMap := map[string]string{}
+	for k, v := range fakeMap {
+		returnMap[k] = v[0]
+	}
+
+	return returnMap
+}