add jwt handling functionality with tests

Signed-off-by: Arnav Gupta <[email protected]>

go.mod

@@ -14,6 +14,7 @@ require (
 require (
 	github.com/andybalholm/brotli v1.0.6 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/golang-jwt/jwt/v5 v5.0.0 // indirect
 	github.com/google/uuid v1.4.0 // indirect
 	github.com/jackc/pgpassfile v1.0.0 // indirect
 	github.com/jackc/pgservicefile v0.0.0-20221227161230-091c0ba34f0a // indirect

go.sum

@@ -8,6 +8,8 @@ github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/gofiber/fiber/v2 v2.50.0 h1:ia0JaB+uw3GpNSCR5nvC5dsaxXjRU5OEu36aytx+zGw=
 github.com/gofiber/fiber/v2 v2.50.0/go.mod h1:21eytvay9Is7S6z+OgPi7c7n4++tnClWmhpimVHMimw=
+github.com/golang-jwt/jwt/v5 v5.0.0 h1:1n1XNM9hk7O9mnQoNBGolZvzebBQ7p93ULHRc28XJUE=
+github.com/golang-jwt/jwt/v5 v5.0.0/go.mod h1:pqrtFR0X4osieyHYxtmOUWsAWrfe1Q5UVIyoH402zdk=
 github.com/google/uuid v1.3.1 h1:KjJaJ9iWZ3jOFZIf1Lqf4laDRCasjl0BCmnEGxkdLb4=
 github.com/google/uuid v1.3.1/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/google/uuid v1.4.0 h1:MtMxsa51/r9yyhkyLsVeVt0B+BGQZzpQiTQ4eHZ8bc4=

src/auth/jwt.go

@@ -0,0 +1,40 @@
+package auth
+
+import (
+	"github.com/golang-jwt/jwt/v5"
+	"github.com/samber/lo"
+	"onepixel_backend/src/models"
+	"strconv"
+	"time"
+)
+
+// TODO: pick JWT_KEY from config
+
+var JWT_KEY = "this is a sample key, should change in prod"
+var JWT_SIGNING_METHOD = jwt.SigningMethodHS256
+
+func CreateJWTFromUser(u *models.User) string {
+	token := jwt.NewWithClaims(JWT_SIGNING_METHOD, jwt.MapClaims{
+		"sub": strconv.Itoa(int(u.ID)),
+		"iat": jwt.NewNumericDate(time.Now()),
+		"exp": jwt.NewNumericDate(time.Now().Add(time.Hour * 24 * 7)), // 7 days
+	})
+
+	return lo.Must(token.SignedString([]byte(JWT_KEY)))
+}
+
+func ValidateJWT(t string) (*uint, error) {
+	claims := jwt.MapClaims{}
+	_, err := jwt.ParseWithClaims(t, claims, func(token *jwt.Token) (interface{}, error) {
+		return []byte(JWT_KEY), nil
+	})
+	if err != nil {
+		return nil, err
+	}
+	sub := uint(lo.Must(strconv.Atoi(lo.Must(claims.GetSubject()))))
+	exp := lo.Must(claims.GetExpirationTime())
+	if exp.Before(time.Now()) {
+		return nil, jwt.ErrTokenExpired
+	}
+	return &sub, nil
+}

tests/auth/jwt_test.go

@@ -0,0 +1,34 @@
+package auth
+
+import (
+	"github.com/gofiber/fiber/v2/log"
+	"github.com/stretchr/testify/assert"
+	"onepixel_backend/src/auth"
+	"onepixel_backend/src/models"
+	"testing"
+)
+
+func TestJwt_CreateToken(t *testing.T) {
+	testUser := &models.User{
+		ID: 12,
+	}
+
+	jwt := auth.CreateJWTFromUser(testUser)
+	log.Info("jwt: ", jwt)
+	assert.NotNil(t, jwt)
+}
+
+func TestJwt_ParseToken(t *testing.T) {
+	testUser := &models.User{
+		ID: 12,
+	}
+
+	jwt := auth.CreateJWTFromUser(testUser)
+	log.Info("jwt: ", jwt)
+	assert.NotNil(t, jwt)
+
+	userID, err := auth.ValidateJWT(jwt)
+	assert.Nil(t, err)
+	assert.NotNil(t, userID)
+	assert.Equal(t, testUser.ID, *userID)
+}