From 8509af210530fc92ca9f57b24972cd2eb34d8c9a Mon Sep 17 00:00:00 2001
From: Didier Stevens <didier.stevens@gmail.com>
Date: Sun, 25 Dec 2022 10:41:45 +0100
Subject: [PATCH] Add new operation: Insert bytes

---
 src/core/config/Categories.json        |  1 +
 src/core/operations/InsertBytes.mjs    | 81 ++++++++++++++++++++++++++
 tests/operations/index.mjs             |  1 +
 tests/operations/tests/InsertBytes.mjs | 78 +++++++++++++++++++++++++
 4 files changed, 161 insertions(+)
 create mode 100644 src/core/operations/InsertBytes.mjs
 create mode 100644 tests/operations/tests/InsertBytes.mjs

diff --git a/src/core/config/Categories.json b/src/core/config/Categories.json
index 075e8d66..71c41a0c 100644
--- a/src/core/config/Categories.json
+++ b/src/core/config/Categories.json
@@ -265,6 +265,7 @@
             "Expand alphabet range",
             "Drop bytes",
             "Take bytes",
+            "Insert bytes",
             "Pad lines",
             "Find / Replace",
             "Regular expression",
diff --git a/src/core/operations/InsertBytes.mjs b/src/core/operations/InsertBytes.mjs
new file mode 100644
index 00000000..ea07e935
--- /dev/null
+++ b/src/core/operations/InsertBytes.mjs
@@ -0,0 +1,81 @@
+/**
+ * @author Didier Stevens [didier.stevens@gmail.com]
+ * @copyright Crown Copyright 2022
+ * @license Apache-2.0
+ */
+
+import Operation from "../Operation.mjs";
+import OperationError from "../errors/OperationError.mjs";
+import {BITWISE_OP_DELIMS} from "../lib/BitwiseOp.mjs";
+import Utils from "../Utils.mjs";
+
+/**
+ * Insert bytes operation
+ */
+class InsertBytes extends Operation {
+
+    /**
+     * InsertBytes constructor
+     */
+    constructor() {
+        super();
+
+        this.name = "Insert bytes";
+        this.module = "Default";
+        this.description = "Insert bytes at arbitrary position. Options 'from end' and 'overwrite' available.";
+        this.infoURL = "";
+        this.inputType = "byteArray";
+        this.outputType = "byteArray";
+        this.args = [
+            {
+                "name": "Bytes",
+                "type": "toggleString",
+                "value": "",
+                "toggleValues": BITWISE_OP_DELIMS
+            },
+            {
+                "name": "Start",
+                "type": "number",
+                "value": 0
+            },
+            {
+                "name": "From end",
+                "type": "boolean",
+                "value": false
+            },
+            {
+                "name": "Overwrite",
+                "type": "boolean",
+                "value": false
+            }
+        ];
+    }
+
+    /**
+     * @param {byteArray} input
+     * @param {Object[]} args
+     * @returns {byteArray}
+     */
+    run(input, args) {
+        const value = Utils.convertToByteArray(args[0].string || "", args[0].option);
+        let start = args[1];
+        const fromend = args[2];
+        const overwrite = args[3];
+
+        if (start < 0)
+            throw new OperationError("Start must not be negative");
+        if (start > input.length)
+            throw new OperationError("Start must not be bigger than input");
+        if (fromend)
+            start = input.length - start;
+        const left = input.slice(0, start);
+        let right = input.slice(start);
+        if (overwrite)
+            right = right.slice(value.length);
+
+        return left.concat(value, right);
+    }
+
+}
+
+export default InsertBytes;
diff --git a/tests/operations/index.mjs b/tests/operations/index.mjs
index 7a3361f2..04cc3f1d 100644
--- a/tests/operations/index.mjs
+++ b/tests/operations/index.mjs
@@ -130,6 +130,7 @@ import "./tests/FletcherChecksum.mjs";
 import "./tests/CMAC.mjs";
 import "./tests/AESKeyWrap.mjs";
 import "./tests/Rabbit.mjs";
+import "./tests/InsertBytes.mjs";
 
 // Cannot test operations that use the File type yet
 // import "./tests/SplitColourChannels.mjs";
diff --git a/tests/operations/tests/InsertBytes.mjs b/tests/operations/tests/InsertBytes.mjs
new file mode 100644
index 00000000..8eca3973
--- /dev/null
+++ b/tests/operations/tests/InsertBytes.mjs
@@ -0,0 +1,78 @@
+/**
+ * InsertBytes test.
+ *
+ * @author Didier Stevens [didier.stevens@gmail.com]
+ * @copyright Crown Copyright 2022
+ * @license Apache-2.0
+ */
+import TestRegister from "../../lib/TestRegister.mjs";
+
+TestRegister.addTests([
+    {
+        name: "Insert bytes - test 1",
+        input: "This is a test",
+        expectedOutput: "This is a test",
+        recipeConfig: [
+            {
+                op: "Insert bytes",
+                args: [{"string": "", "option": "Hex"}, 0, false, false],
+            },
+        ],
+    },
+    {
+        name: "Insert bytes - test 2",
+        input: "This is a test",
+        expectedOutput: "AThis is a test",
+        recipeConfig: [
+            {
+                op: "Insert bytes",
+                args: [{"string": "41", "option": "Hex"}, 0, false, false],
+            },
+        ],
+    },
+    {
+        name: "Insert bytes - test 3",
+        input: "This is a test",
+        expectedOutput: "This is a testA",
+        recipeConfig: [
+            {
+                op: "Insert bytes",
+                args: [{"string": "41", "option": "Hex"}, 0, true, false],
+            },
+        ],
+    },
+    {
+        name: "Insert bytes - test 4",
+        input: "This is a test",
+        expectedOutput: "Ahis is a test",
+        recipeConfig: [
+            {
+                op: "Insert bytes",
+                args: [{"string": "41", "option": "Hex"}, 0, false, true],
+            },
+        ],
+    },
+    {
+        name: "Insert bytes - test 5",
+        input: "This is a test",
+        expectedOutput: "This is a tesA",
+        recipeConfig: [
+            {
+                op: "Insert bytes",
+                args: [{"string": "41", "option": "Hex"}, 1, true, true],
+            },
+        ],
+    },
+    {
+        name: "Insert bytes - test 6",
+        input: "This is a test",
+        expectedOutput: "This is not a test",
+        recipeConfig: [
+            {
+                op: "Insert bytes",
+                args: [{"string": "not ", "option": "Latin1"}, 8, false, false],
+            },
+        ],
+    },
+
+]);