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Add Strip TCP header operation

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c65722 2024-09-15 14:29:35 +01:00
parent d635cca210
commit 748379f0b0
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4 changed files with 188 additions and 0 deletions
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1
src/core/config/Categories.json
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@ -235,6 +235,7 @@
"Parse IPv6 address",
"Parse IPv4 header",
"Parse TCP",
"Strip TCP header",
"Parse UDP",
"Parse SSH Host Key",
"Parse URI",

60
src/core/operations/StripTCPHeader.mjs Normal file
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@ -0,0 +1,60 @@
/**
* @author c65722 []
* @copyright Crown Copyright 2024
* @license Apache-2.0
*/
import Operation from "../Operation.mjs";
import OperationError from "../errors/OperationError.mjs";
import Stream from "../lib/Stream.mjs";
/**
* Strip TCP header operation
*/
class StripTCPHeader extends Operation {
/**
* StripTCPHeader constructor
*/
constructor() {
super();
this.name = "Strip TCP header";
this.module = "Default";
this.description = "Strips the TCP header from a TCP segment, outputting the payload.";
this.infoURL = "https://wikipedia.org/wiki/Transmission_Control_Protocol";
this.inputType = "ArrayBuffer";
this.outputType = "ArrayBuffer";
this.args = [];
}
/**
* @param {ArrayBuffer} input
* @param {Object[]} args
* @returns {ArrayBuffer}
*/
run(input, args) {
const MIN_HEADER_LEN = 20;
const DATA_OFFSET_OFFSET = 12;
const DATA_OFFSET_LEN_BITS = 4;
const s = new Stream(new Uint8Array(input));
if (s.length < MIN_HEADER_LEN) {
throw new OperationError("Need at least 20 bytes for a TCP Header");
}
s.moveTo(DATA_OFFSET_OFFSET);
const dataOffsetWords = s.readBits(DATA_OFFSET_LEN_BITS);
const dataOffsetBytes = dataOffsetWords * 4;
if (s.length < dataOffsetBytes) {
throw new OperationError("Input length is less than data offset");
}
s.moveTo(dataOffsetBytes);
return s.getBytes().buffer;
}
}
export default StripTCPHeader;

1
tests/operations/index.mjs
View file

@ -142,6 +142,7 @@ import "./tests/SIGABA.mjs";
import "./tests/SM4.mjs";
// import "./tests/SplitColourChannels.mjs"; // Cannot test operations that use the File type yet
import "./tests/StrUtils.mjs";
import "./tests/StripTCPHeader.mjs";
import "./tests/Subsection.mjs";
import "./tests/SwapCase.mjs";
import "./tests/SymmetricDifference.mjs";

126
tests/operations/tests/StripTCPHeader.mjs Normal file
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@ -0,0 +1,126 @@
/**
* Strip TCP header tests.
*
* @author c65722 []
* @copyright Crown Copyright 2024
* @license Apache-2.0
*/
import TestRegister from "../../lib/TestRegister.mjs";
TestRegister.addTests([
{
name: "Strip TCP header: No options, No payload",
input: "7f900050000fa4b2000cb2a45010bff100000000",
expectedOutput: "",
recipeConfig: [
{
op: "From Hex",
args: ["None"]
},
{
op: "Strip TCP header",
args: [],
},
{
op: "To Hex",
args: ["None", 0]
}
]
},
{
name: "Strip TCP header: No options, Payload",
input: "7f900050000fa4b2000cb2a45010bff100000000ffffffffffffffff",
expectedOutput: "ffffffffffffffff",
recipeConfig: [
{
op: "From Hex",
args: ["None"]
},
{
op: "Strip TCP header",
args: [],
},
{
op: "To Hex",
args: ["None", 0]
}
]
},
{
name: "Strip TCP header: Options, No payload",
input: "7f900050000fa4b2000cb2a47010bff100000000020405b404020000",
expectedOutput: "",
recipeConfig: [
{
op: "From Hex",
args: ["None"]
},
{
op: "Strip TCP header",
args: [],
},
{
op: "To Hex",
args: ["None", 0]
}
]
},
{
name: "Strip TCP header: Options, Payload",
input: "7f900050000fa4b2000cb2a47010bff100000000020405b404020000ffffffffffffffff",
expectedOutput: "ffffffffffffffff",
recipeConfig: [
{
op: "From Hex",
args: ["None"]
},
{
op: "Strip TCP header",
args: [],
},
{
op: "To Hex",
args: ["None", 0]
}
]
},
{
name: "Strip TCP header: Input length less than minimum header length",
input: "7f900050000fa4b2000cb2a45010bff1000000",
expectedOutput: "Need at least 20 bytes for a TCP Header",
recipeConfig: [
{
op: "From Hex",
args: ["None"]
},
{
op: "Strip TCP header",
args: [],
},
{
op: "To Hex",
args: ["None", 0]
}
]
},
{
name: "Strip TCP header: Input length less than data offset",
input: "7f900050000fa4b2000cb2a47010bff100000000",
expectedOutput: "Input length is less than data offset",
recipeConfig: [
{
op: "From Hex",
args: ["None"]
},
{
op: "Strip TCP header",
args: [],
},
{
op: "To Hex",
args: ["None", 0]
}
]
}
]);