add an example for sessions + view data as requested

_examples/auth/jwt/tutorial/user.go

@@ -0,0 +1,63 @@
+package main
+
+import "golang.org/x/crypto/bcrypt"
+
+func init() {
+	generateSampleUsers()
+}
+
+// User represents our User model.
+type User struct {
+	ID             uint64 `json:"id"`
+	Username       string `json:"username"`
+	HashedPassword []byte `json:"-"`
+}
+
+// Users represents a user database.
+// For the sake of the tutorial we use a simple slice of users.
+var Users []User
+
+func generateSampleUsers() {
+	Users = []User{
+		{ID: 1, Username: "vasiliki", HashedPassword: mustGeneratePassword("vasiliki_pass")}, // my grandmother.
+		{ID: 2, Username: "kataras", HashedPassword: mustGeneratePassword("kataras_pass")},   // me.
+		{ID: 3, Username: "george", HashedPassword: mustGeneratePassword("george_pass")},     // my young brother.
+		{ID: 4, Username: "kwstas", HashedPassword: mustGeneratePassword("kwstas_pass")},     // my youngest brother.
+	}
+}
+
+func fetchUser(username, password string) (User, bool) {
+	for _, u := range Users { // our example uses a static slice.
+		if u.Username == username {
+			// we compare the user input and the stored hashed password.
+			ok := ValidatePassword(password, u.HashedPassword)
+			if ok {
+				return u, true
+			}
+		}
+	}
+
+	return User{}, false
+}
+
+// mustGeneratePassword same as GeneratePassword but panics on errors.
+func mustGeneratePassword(userPassword string) []byte {
+	hashed, err := GeneratePassword(userPassword)
+	if err != nil {
+		panic(err)
+	}
+
+	return hashed
+}
+
+// GeneratePassword will generate a hashed password for us based on the
+// user's input.
+func GeneratePassword(userPassword string) ([]byte, error) {
+	return bcrypt.GenerateFromPassword([]byte(userPassword), bcrypt.DefaultCost)
+}
+
+// ValidatePassword will check if passwords are matched.
+func ValidatePassword(userPassword string, hashed []byte) bool {
+	err := bcrypt.CompareHashAndPassword(hashed, []byte(userPassword))
+	return err == nil
+}