2 files changed, 19 insertions, 4 deletions
diff --git a/lib/private/Security/CSRF/CsrfToken.php b/lib/private/Security/CSRF/CsrfToken.php
index bf61e339f77..dce9a83b727 100644
--- a/lib/private/Security/CSRF/CsrfToken.php
+++ b/lib/private/Security/CSRF/CsrfToken.php
@@ -33,6 +33,8 @@ namespace OC\Security\CSRF;
 class CsrfToken {
 	/** @var string */
 	private $value;
+	/** @var string */
+	private $encryptedValue = '';
 
 	/**
 	 * @param string $value Value of the token. Can be encrypted or not encrypted.
@@ -48,8 +50,12 @@ class CsrfToken {
 	 * @return string
 	 */
 	public function getEncryptedValue() {
-		$sharedSecret = base64_encode(random_bytes(strlen($this->value)));
-		return base64_encode($this->value ^ $sharedSecret) .':'.$sharedSecret;
+		if($this->encryptedValue === '') {
+			$sharedSecret = base64_encode(random_bytes(strlen($this->value)));
+			$this->encryptedValue = base64_encode($this->value ^ $sharedSecret) . ':' . $sharedSecret;
+		}
+
+		return $this->encryptedValue;
 	}
 
 	/**
diff --git a/lib/private/Security/CSRF/CsrfTokenManager.php b/lib/private/Security/CSRF/CsrfTokenManager.php
index d621cc2c29f..b43ca3d3679 100644
--- a/lib/private/Security/CSRF/CsrfTokenManager.php
+++ b/lib/private/Security/CSRF/CsrfTokenManager.php
@@ -34,6 +34,8 @@ class CsrfTokenManager {
 	private $tokenGenerator;
 	/** @var SessionStorage */
 	private $sessionStorage;
+	/** @var CsrfToken|null */
+	private $csrfToken = null;
 
 	/**
 	 * @param CsrfTokenGenerator $tokenGenerator
@@ -51,6 +53,10 @@ class CsrfTokenManager {
 	 * @return CsrfToken
 	 */
 	public function getToken() {
+		if(!is_null($this->csrfToken)) {
+			return $this->csrfToken;
+		}
+
 		if($this->sessionStorage->hasToken()) {
 			$value = $this->sessionStorage->getToken();
 		} else {
@@ -58,7 +64,8 @@ class CsrfTokenManager {
 			$this->sessionStorage->setToken($value);
 		}
 
-		return new CsrfToken($value);
+		$this->csrfToken = new CsrfToken($value);
+		return $this->csrfToken;
 	}
 
 	/**
@@ -69,13 +76,15 @@ class CsrfTokenManager {
 	public function refreshToken() {
 		$value = $this->tokenGenerator->generateToken();
 		$this->sessionStorage->setToken($value);
-		return new CsrfToken($value);
+		$this->csrfToken = new CsrfToken($value);
+		return $this->csrfToken;
 	}
 
 	/**
 	 * Remove the current token from the storage.
 	 */
 	public function removeToken() {
+		$this->csrfToken = null;
 		$this->sessionStorage->removeToken();
 	}