Support File Based Encryption
Change-Id: Ib688ddd0c32d3999590cacd86b6d9b18eac336e9
diff --git a/crypto/ext4crypt/ScryptParameters.cpp b/crypto/ext4crypt/ScryptParameters.cpp
new file mode 100644
index 0000000..669809b
--- /dev/null
+++ b/crypto/ext4crypt/ScryptParameters.cpp
@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "ScryptParameters.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+bool parse_scrypt_parameters(const char* paramstr, int *Nf, int *rf, int *pf) {
+ int params[3];
+ char *token;
+ char *saveptr;
+ int i;
+
+ /*
+ * The token we're looking for should be three integers separated by
+ * colons (e.g., "12:8:1"). Scan the property to make sure it matches.
+ */
+ for (i = 0, token = strtok_r(const_cast<char *>(paramstr), ":", &saveptr);
+ token != nullptr && i < 3;
+ i++, token = strtok_r(nullptr, ":", &saveptr)) {
+ char *endptr;
+ params[i] = strtol(token, &endptr, 10);
+
+ /*
+ * Check that there was a valid number and it's 8-bit.
+ */
+ if ((*token == '\0') || (*endptr != '\0') || params[i] < 0 || params[i] > 255) {
+ return false;
+ }
+ }
+ if (token != nullptr) {
+ return false;
+ }
+ *Nf = params[0]; *rf = params[1]; *pf = params[2];
+ return true;
+}