Implement API Key Model Logic in Go

go-backend/models/api_key.go

@@ -1,6 +1,11 @@
 package models
 
 import (
+	"crypto/hmac"
+	"crypto/sha512"
+	"encoding/hex"
+	"errors"
+	"os"
 	"time"
 
 	"gorm.io/gorm"
@@ -14,4 +19,69 @@ type APIKey struct {
 	Name          string
 	TokenDigest   string `gorm:"not null;unique"`
 	BearerID      uint   `gorm:"not null"`
+	Token         string `gorm:"-"` // Virtual attribute for raw token value
+}
+
+// BeforeCreate is a GORM hook that generates the token digest before creating a new APIKey record
+func (apiKey *APIKey) BeforeCreate(tx *gorm.DB) (err error) {
+	if apiKey.Token == "" {
+		return errors.New("token is required")
+	}
+
+	apiKey.TokenDigest, err = generateTokenHMACDigest(apiKey.Token)
+	return
+}
+
+// AuthenticateByToken finds an API key by its token
+func AuthenticateByToken(db *gorm.DB, token string) (*APIKey, error) {
+	return authenticateByToken(db, token, false)
+}
+
+// AuthenticateByToken finds an API key by its token and returns an error if not found
+func AuthenticateByTokenBang(db *gorm.DB, token string) (*APIKey, error) {
+	return authenticateByToken(db, token, true)
+}
+
+func authenticateByToken(db *gorm.DB, token string, bang bool) (*APIKey, error) {
+	digest, err := generateTokenHMACDigest(token)
+	if err != nil {
+		return nil, err
+	}
+
+	var apiKey APIKey
+	var result *gorm.DB
+	if bang {
+		result = db.Where("token_digest = ?", digest).First(&apiKey)
+	} else {
+		result = db.Where("token_digest = ?", digest).Limit(1).Find(&apiKey)
+	}
+
+	if result.Error != nil {
+		return nil, result.Error
+	}
+
+	if result.RowsAffected == 0 {
+		return nil, nil // Return nil if no record is found
+	}
+
+	return &apiKey, nil
+}
+
+func generateTokenHMACDigest(token string) (string, error) {
+	hmacSecretKey := os.Getenv("API_KEY_HMAC_SECRET_KEY")
+	if hmacSecretKey == "" {
+		// In test environment, use a default value
+		if os.Getenv("GO_ENV") == "test" {
+			hmacSecretKey = "test"
+		} else {
+			return "", errors.New("API_KEY_HMAC_SECRET_KEY is not set")
+		}
+	}
+
+	mac := hmac.New(sha512.New, []byte(hmacSecretKey))
+	_, err := mac.Write([]byte(token))
+	if err != nil {
+		return "", err
+	}
+	return hex.EncodeToString(mac.Sum(nil)), nil
 }