diff --git a/keystore/keystore.cpp b/keystore/keystore.cpp
index 2208936..5be31eb 100644
--- a/keystore/keystore.cpp
+++ b/keystore/keystore.cpp
@@ -2671,7 +2671,8 @@
     }
 
     void finish(const sp<IBinder>& token, const KeymasterArguments& params,
-                const uint8_t* signature, size_t signatureLength, OperationResult* result) {
+                const uint8_t* signature, size_t signatureLength,
+                const uint8_t* entropy, size_t entropyLength, OperationResult* result) {
         if (!checkAllowedOperationParams(params.params)) {
             result->resultCode = KM_ERROR_INVALID_ARGUMENT;
             return;
@@ -2688,12 +2689,24 @@
             result->resultCode = authResult;
             return;
         }
+        keymaster_error_t err;
+        if (entropy) {
+            if (dev->add_rng_entropy) {
+                err = dev->add_rng_entropy(dev, entropy, entropyLength);
+            } else {
+                err = KM_ERROR_UNIMPLEMENTED;
+            }
+            if (err) {
+                result->resultCode = err;
+                return;
+            }
+        }
 
         keymaster_key_param_set_t inParams = {opParams.data(), opParams.size()};
         keymaster_blob_t input = {signature, signatureLength};
         keymaster_blob_t output = {NULL, 0};
         keymaster_key_param_set_t outParams = {NULL, 0};
-        keymaster_error_t err = dev->finish(dev, handle, &inParams, &input, &outParams, &output);
+        err = dev->finish(dev, handle, &inParams, &input, &outParams, &output);
         // Remove the operation regardless of the result
         mOperationMap.removeOperation(token);
         mAuthTokenTable.MarkCompleted(handle);