feat: api key authentication (#291)

Co-authored-by: Elias Schneider <login@eliasschneider.com>

backend/internal/service/api_key_service.go

@@ -0,0 +1,102 @@
+package service
+
+import (
+	"errors"
+	datatype "github.com/pocket-id/pocket-id/backend/internal/model/types"
+	"log"
+	"time"
+
+	"github.com/pocket-id/pocket-id/backend/internal/common"
+	"github.com/pocket-id/pocket-id/backend/internal/dto"
+	"github.com/pocket-id/pocket-id/backend/internal/model"
+	"github.com/pocket-id/pocket-id/backend/internal/utils"
+	"gorm.io/gorm"
+)
+
+type ApiKeyService struct {
+	db *gorm.DB
+}
+
+func NewApiKeyService(db *gorm.DB) *ApiKeyService {
+	return &ApiKeyService{db: db}
+}
+
+func (s *ApiKeyService) ListApiKeys(userID string, sortedPaginationRequest utils.SortedPaginationRequest) ([]model.ApiKey, utils.PaginationResponse, error) {
+	query := s.db.Where("user_id = ?", userID).Model(&model.ApiKey{})
+
+	var apiKeys []model.ApiKey
+	pagination, err := utils.PaginateAndSort(sortedPaginationRequest, query, &apiKeys)
+	if err != nil {
+		return nil, utils.PaginationResponse{}, err
+	}
+
+	return apiKeys, pagination, nil
+}
+
+func (s *ApiKeyService) CreateApiKey(userID string, input dto.ApiKeyCreateDto) (model.ApiKey, string, error) {
+	// Check if expiration is in the future
+	if !input.ExpiresAt.ToTime().After(time.Now()) {
+		return model.ApiKey{}, "", &common.APIKeyExpirationDateError{}
+	}
+
+	// Generate a secure random API key
+	token, err := utils.GenerateRandomAlphanumericString(32)
+	if err != nil {
+		return model.ApiKey{}, "", err
+	}
+
+	apiKey := model.ApiKey{
+		Name:        input.Name,
+		Key:         utils.CreateSha256Hash(token), // Hash the token for storage
+		Description: &input.Description,
+		ExpiresAt:   datatype.DateTime(input.ExpiresAt),
+		UserID:      userID,
+	}
+
+	if err := s.db.Create(&apiKey).Error; err != nil {
+		return model.ApiKey{}, "", err
+	}
+
+	// Return the raw token only once - it cannot be retrieved later
+	return apiKey, token, nil
+}
+
+func (s *ApiKeyService) RevokeApiKey(userID, apiKeyID string) error {
+	var apiKey model.ApiKey
+	if err := s.db.Where("id = ? AND user_id = ?", apiKeyID, userID).First(&apiKey).Error; err != nil {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			return &common.APIKeyNotFoundError{}
+		}
+		return err
+	}
+
+	return s.db.Delete(&apiKey).Error
+}
+
+func (s *ApiKeyService) ValidateApiKey(apiKey string) (model.User, error) {
+	if apiKey == "" {
+		return model.User{}, &common.NoAPIKeyProvidedError{}
+	}
+
+	var key model.ApiKey
+	hashedKey := utils.CreateSha256Hash(apiKey)
+
+	if err := s.db.Preload("User").Where("key = ? AND expires_at > ?",
+		hashedKey, time.Now()).Preload("User").First(&key).Error; err != nil {
+
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			return model.User{}, &common.InvalidAPIKeyError{}
+		}
+
+		return model.User{}, err
+	}
+
+	// Update last used time
+	now := datatype.DateTime(time.Now())
+	key.LastUsedAt = &now
+	if err := s.db.Save(&key).Error; err != nil {
+		log.Printf("Failed to update last used time: %v", err)
+	}
+
+	return key.User, nil
+}