From bd7492de28963b7e74e8e5d3f17ec9a5a287d9c3 Mon Sep 17 00:00:00 2001
From: Ethan Yonker <dees_troy@teamw.in>
Date: Wed, 7 Dec 2016 13:55:01 -0600
Subject: Support File Based Encryption

Change-Id: Ib688ddd0c32d3999590cacd86b6d9b18eac336e9
---
 crypto/ext4crypt/ScryptParameters.cpp | 50 +++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)
 create mode 100644 crypto/ext4crypt/ScryptParameters.cpp

(limited to 'crypto/ext4crypt/ScryptParameters.cpp')

diff --git a/crypto/ext4crypt/ScryptParameters.cpp b/crypto/ext4crypt/ScryptParameters.cpp
new file mode 100644
index 000000000..669809b9f
--- /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;
+}
-- 
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