Create a function to generate a token

internal/models/tokens.go

@@ -0,0 +1,42 @@
+package models
+
+import (
+	"crypto/rand"
+	"crypto/sha256"
+	"encoding/base32"
+	"time"
+)
+
+const (
+	ScopeAuthentication = "authentication"
+)
+
+// Token is the type for authentication tokens
+type Token struct {
+	PlainText string    `json:"token"`
+	UserID    int64     `json:"-"`
+	Hash      []byte    `json:"-"`
+	Expiry    time.Time `json:"expiry"`
+	Scope     string    `json:"-"`
+}
+
+// GenerateToken Generates a token that lasts for ttl, and returns it
+func GenerateToken(userID int, ttl time.Duration, scope string) (*Token, error) {
+	token := &Token{
+		UserID: int64(userID),
+		Expiry: time.Now().Add(ttl),
+		Scope:  scope,
+	}
+
+	randomBytes := make([]byte, 16)
+	_, err := rand.Read(randomBytes)
+	if err != nil {
+		return nil, err
+	}
+
+	token.PlainText = base32.StdEncoding.WithPadding((base32.NoPadding)).
+		EncodeToString((randomBytes))
+	hash := sha256.Sum256([]byte(token.PlainText))
+	token.Hash = hash[:]
+	return token, nil
+}