commit 125febcb5d1888fa82e8c2eb307513598a537999
author Shawn Willden <swillden@google.com> Mon Dec 08 08:15:14 2014 -0700
committer Shawn Willden <swillden@google.com> Tue Dec 30 08:03:59 2014 -0700
tree 43e9af5196a5e4d42ff3fa15d5214c26a1ab32c1
parent d7fe0436fa9af91c1e67833f2527f9ab8be3403f

Refactor Update operation to return amount of input consumed.

Per the keymaster "update" API documentation, implementations need not
consume all provided input, and must return information about how much
they did consume, so the caller knows to resend the unprocessed portion.
It's convenient for the AES OCB mode encryption to sometimes process
less than is provided, but the Update operation interfaces didn't
account for not consuming all data.

Change-Id: I07fa3f490c0eb25a09302b1266becaf81f6f5243

google_keymaster_test.cpp

diff --git a/google_keymaster_test.cpp b/google_keymaster_test.cpp
index f6ee1d0..a786c4d 100644
--- a/google_keymaster_test.cpp
+++ b/google_keymaster_test.cpp
@@ -471,6 +471,7 @@
         device.UpdateOperation(update_request, &update_response);
         ASSERT_EQ(KM_ERROR_OK, update_response.error);
         EXPECT_EQ(0U, update_response.output.available_read());
+        EXPECT_EQ(size, update_response.input_consumed);
 
         FinishOperationRequest finish_request;
         finish_request.op_handle = begin_response.op_handle;
@@ -612,6 +613,7 @@
     device.UpdateOperation(update_request, &update_response);
     ASSERT_EQ(KM_ERROR_OK, update_response.error);
     EXPECT_EQ(0U, update_response.output.available_read());
+    EXPECT_EQ(31U, update_response.input_consumed);
 
     FinishOperationRequest finish_request;
     finish_request.op_handle = begin_response.op_handle;
@@ -651,6 +653,7 @@
         device.UpdateOperation(update_request, &update_response);
         ASSERT_EQ(KM_ERROR_OK, update_response.error);
         EXPECT_EQ(0U, update_response.output.available_read());
+        EXPECT_EQ(message_len, update_response.input_consumed);
 
         FinishOperationRequest finish_request;
         finish_request.op_handle = begin_response.op_handle;
@@ -968,7 +971,7 @@
     }
 
     keymaster_error_t UpdateOperation(uint64_t op_handle, const void* message, size_t size,
-                                      string* output) {
+                                      string* output, size_t* input_consumed) {
         UpdateOperationRequest update_request;
         update_request.op_handle = op_handle;
         update_request.input.Reinitialize(message, size);
@@ -978,6 +981,7 @@
         if (update_response.error == KM_ERROR_OK)
             output->append(reinterpret_cast<const char*>(update_response.output.peek_read()),
                            update_response.output.available_read());
+        *input_consumed = update_response.input_consumed;
         return update_response.error;
     }
 
@@ -998,8 +1002,11 @@
         EXPECT_EQ(KM_ERROR_OK, BeginOperation(purpose, key_blob, &op_handle));
 
         string result;
-        EXPECT_EQ(KM_ERROR_OK, UpdateOperation(op_handle, message, size, &result));
+        size_t input_consumed;
+        EXPECT_EQ(KM_ERROR_OK, UpdateOperation(op_handle, message, size, &result, &input_consumed));
+        EXPECT_EQ(size, input_consumed);
         EXPECT_EQ(KM_ERROR_OK, FinishOperation(op_handle, &result));
+
         return result;
     }
 
@@ -1053,10 +1060,12 @@
     const char message[] = "12345678901234567890123";
     uint64_t op_handle;
     string result;
+    size_t input_consumed;
 
     EXPECT_EQ(KM_ERROR_OK,
               BeginOperation(KM_PURPOSE_ENCRYPT, generate_response_.key_blob, &op_handle));
-    EXPECT_EQ(KM_ERROR_OK, UpdateOperation(op_handle, message, array_size(message), &result));
+    EXPECT_EQ(KM_ERROR_OK,
+              UpdateOperation(op_handle, message, array_size(message), &result, &input_consumed));
     EXPECT_EQ(KM_ERROR_INVALID_INPUT_LENGTH, FinishOperation(op_handle, &result));
     EXPECT_EQ(0, result.size());
 }
@@ -1072,10 +1081,11 @@
 
     uint64_t op_handle;
     string result;
+    size_t input_consumed;
     EXPECT_EQ(KM_ERROR_OK,
               BeginOperation(KM_PURPOSE_DECRYPT, generate_response_.key_blob, &op_handle));
-    EXPECT_EQ(KM_ERROR_OK,
-              UpdateOperation(op_handle, ciphertext.data(), ciphertext.size(), &result));
+    EXPECT_EQ(KM_ERROR_OK, UpdateOperation(op_handle, ciphertext.data(), ciphertext.size(), &result,
+                                           &input_consumed));
     EXPECT_EQ(KM_ERROR_UNKNOWN_ERROR, FinishOperation(op_handle, &result));
     EXPECT_EQ(0, result.size());
 }
@@ -1108,10 +1118,12 @@
     const char message[] = "1234567890123456789012345678901234567890123456789012";
     uint64_t op_handle;
     string result;
+    size_t input_consumed;
 
     EXPECT_EQ(KM_ERROR_OK,
               BeginOperation(KM_PURPOSE_ENCRYPT, generate_response_.key_blob, &op_handle));
-    EXPECT_EQ(KM_ERROR_OK, UpdateOperation(op_handle, message, array_size(message), &result));
+    EXPECT_EQ(KM_ERROR_OK,
+              UpdateOperation(op_handle, message, array_size(message), &result, &input_consumed));
     EXPECT_EQ(KM_ERROR_INVALID_INPUT_LENGTH, FinishOperation(op_handle, &result));
     EXPECT_EQ(0, result.size());
 }
@@ -1127,10 +1139,11 @@
 
     uint64_t op_handle;
     string result;
+    size_t input_consumed;
     EXPECT_EQ(KM_ERROR_OK,
               BeginOperation(KM_PURPOSE_DECRYPT, generate_response_.key_blob, &op_handle));
-    EXPECT_EQ(KM_ERROR_OK,
-              UpdateOperation(op_handle, ciphertext.data(), ciphertext.size(), &result));
+    EXPECT_EQ(KM_ERROR_OK, UpdateOperation(op_handle, ciphertext.data(), ciphertext.size(), &result,
+                                           &input_consumed));
     EXPECT_EQ(KM_ERROR_UNKNOWN_ERROR, FinishOperation(op_handle, &result));
     EXPECT_EQ(0, result.size());
 }