ServiceAccounts: Add identifiable token prefix to service account tokens (#49011)

* Add prefixed API key gen.

* Retrieve API Key by hash

* Handle prefixed API keys for login

* Add placeholder key generator

* fix spelling

* add get by hash sqlstore test

* reformat query

* quote usage of reserved keyword key

* use constant

* improve error handling and pre-select key type

Co-authored-by: Victor Cinaglia <victor@grafana.com>

* nits

Co-authored-by: Victor Cinaglia <victor@grafana.com>

pkg/services/sqlstore/apikey.go

@@ -2,6 +2,7 @@ package sqlstore
 
 import (
 	"context"
+	"fmt"
 	"time"
 
 	"xorm.io/xorm"
@@ -144,3 +145,19 @@ func (ss *SQLStore) GetApiKeyByName(ctx context.Context, query *models.GetApiKey
 		return nil
 	})
 }
+
+func (ss *SQLStore) GetAPIKeyByHash(ctx context.Context, hash string) (*models.ApiKey, error) {
+	var apikey models.ApiKey
+	err := ss.WithDbSession(ctx, func(sess *DBSession) error {
+		has, err := sess.Table("api_key").Where(fmt.Sprintf("%s = ?", dialect.Quote("key")), hash).Get(&apikey)
+		if err != nil {
+			return err
+		} else if !has {
+			return models.ErrInvalidApiKey
+		}
+
+		return nil
+	})
+
+	return &apikey, err
+}