cyberchef
Version:
The Cyber Swiss Army Knife for encryption, encoding, compression and data analysis.
333 lines (292 loc) • 9.49 kB
JavaScript
/**
* @author n1474335 [n1474335@gmail.com]
* @copyright Crown Copyright 2016
* @license Apache-2.0
*/
import Operation from "../Operation.mjs";
import OperationError from "../errors/OperationError.mjs";
/**
* Parse UNIX file permissions operation
*/
class ParseUNIXFilePermissions extends Operation {
/**
* ParseUNIXFilePermissions constructor
*/
constructor() {
super();
this.name = "Parse UNIX file permissions";
this.module = "Default";
this.description = "Given a UNIX/Linux file permission string in octal or textual format, this operation explains which permissions are granted to which user groups.<br><br>Input should be in either octal (e.g. <code>755</code>) or textual (e.g. <code>drwxr-xr-x</code>) format.";
this.infoURL = "https://wikipedia.org/wiki/File_system_permissions#Traditional_Unix_permissions";
this.inputType = "string";
this.outputType = "string";
this.args = [];
this.checks = [
{
pattern: "^\\s*d[rxw-]{9}\\s*$",
flags: "",
args: []
}
];
}
/**
* @param {string} input
* @param {Object[]} args
* @returns {string}
*/
run(input, args) {
const perms = {
d: false, // directory
sl: false, // symbolic link
np: false, // named pipe
s: false, // socket
cd: false, // character device
bd: false, // block device
dr: false, // door
sb: false, // sticky bit
su: false, // setuid
sg: false, // setgid
ru: false, // read user
wu: false, // write user
eu: false, // execute user
rg: false, // read group
wg: false, // write group
eg: false, // execute group
ro: false, // read other
wo: false, // write other
eo: false // execute other
};
let d = 0,
u = 0,
g = 0,
o = 0,
output = "",
octal = null,
textual = null;
if (input.search(/\s*[0-7]{1,4}\s*/i) === 0) {
// Input is octal
octal = input.match(/\s*([0-7]{1,4})\s*/i)[1];
if (octal.length === 4) {
d = parseInt(octal[0], 8);
u = parseInt(octal[1], 8);
g = parseInt(octal[2], 8);
o = parseInt(octal[3], 8);
} else {
if (octal.length > 0) u = parseInt(octal[0], 8);
if (octal.length > 1) g = parseInt(octal[1], 8);
if (octal.length > 2) o = parseInt(octal[2], 8);
}
perms.su = d >> 2 & 0x1;
perms.sg = d >> 1 & 0x1;
perms.sb = d & 0x1;
perms.ru = u >> 2 & 0x1;
perms.wu = u >> 1 & 0x1;
perms.eu = u & 0x1;
perms.rg = g >> 2 & 0x1;
perms.wg = g >> 1 & 0x1;
perms.eg = g & 0x1;
perms.ro = o >> 2 & 0x1;
perms.wo = o >> 1 & 0x1;
perms.eo = o & 0x1;
} else if (input.search(/\s*[dlpcbDrwxsStT-]{1,10}\s*/) === 0) {
// Input is textual
textual = input.match(/\s*([dlpcbDrwxsStT-]{1,10})\s*/)[1];
switch (textual[0]) {
case "d":
perms.d = true;
break;
case "l":
perms.sl = true;
break;
case "p":
perms.np = true;
break;
case "s":
perms.s = true;
break;
case "c":
perms.cd = true;
break;
case "b":
perms.bd = true;
break;
case "D":
perms.dr = true;
break;
}
if (textual.length > 1) perms.ru = textual[1] === "r";
if (textual.length > 2) perms.wu = textual[2] === "w";
if (textual.length > 3) {
switch (textual[3]) {
case "x":
perms.eu = true;
break;
case "s":
perms.eu = true;
perms.su = true;
break;
case "S":
perms.su = true;
break;
}
}
if (textual.length > 4) perms.rg = textual[4] === "r";
if (textual.length > 5) perms.wg = textual[5] === "w";
if (textual.length > 6) {
switch (textual[6]) {
case "x":
perms.eg = true;
break;
case "s":
perms.eg = true;
perms.sg = true;
break;
case "S":
perms.sg = true;
break;
}
}
if (textual.length > 7) perms.ro = textual[7] === "r";
if (textual.length > 8) perms.wo = textual[8] === "w";
if (textual.length > 9) {
switch (textual[9]) {
case "x":
perms.eo = true;
break;
case "t":
perms.eo = true;
perms.sb = true;
break;
case "T":
perms.sb = true;
break;
}
}
} else {
throw new OperationError("Invalid input format.\nPlease enter the permissions in either octal (e.g. 755) or textual (e.g. drwxr-xr-x) format.");
}
output += "Textual representation: " + permsToStr(perms);
output += "\nOctal representation: " + permsToOctal(perms);
// File type
if (textual) {
output += "\nFile type: " + ftFromPerms(perms);
}
// setuid, setgid
if (perms.su) {
output += "\nThe setuid flag is set";
}
if (perms.sg) {
output += "\nThe setgid flag is set";
}
// sticky bit
if (perms.sb) {
output += "\nThe sticky bit is set";
}
// Permission matrix
output += `
+---------+-------+-------+-------+
| | User | Group | Other |
+---------+-------+-------+-------+
| Read | ${perms.ru ? "X" : " "} | ${perms.rg ? "X" : " "} | ${perms.ro ? "X" : " "} |
+---------+-------+-------+-------+
| Write | ${perms.wu ? "X" : " "} | ${perms.wg ? "X" : " "} | ${perms.wo ? "X" : " "} |
+---------+-------+-------+-------+
| Execute | ${perms.eu ? "X" : " "} | ${perms.eg ? "X" : " "} | ${perms.eo ? "X" : " "} |
+---------+-------+-------+-------+`;
return output;
}
}
/**
* Given a permissions object dictionary, generates a textual permissions string.
*
* @param {Object} perms
* @returns {string}
*/
function permsToStr(perms) {
let str = "",
type = "-";
if (perms.d) type = "d";
if (perms.sl) type = "l";
if (perms.np) type = "p";
if (perms.s) type = "s";
if (perms.cd) type = "c";
if (perms.bd) type = "b";
if (perms.dr) type = "D";
str = type;
str += perms.ru ? "r" : "-";
str += perms.wu ? "w" : "-";
if (perms.eu && perms.su) {
str += "s";
} else if (perms.su) {
str += "S";
} else if (perms.eu) {
str += "x";
} else {
str += "-";
}
str += perms.rg ? "r" : "-";
str += perms.wg ? "w" : "-";
if (perms.eg && perms.sg) {
str += "s";
} else if (perms.sg) {
str += "S";
} else if (perms.eg) {
str += "x";
} else {
str += "-";
}
str += perms.ro ? "r" : "-";
str += perms.wo ? "w" : "-";
if (perms.eo && perms.sb) {
str += "t";
} else if (perms.sb) {
str += "T";
} else if (perms.eo) {
str += "x";
} else {
str += "-";
}
return str;
}
/**
* Given a permissions object dictionary, generates an octal permissions string.
*
* @param {Object} perms
* @returns {string}
*/
function permsToOctal(perms) {
let d = 0,
u = 0,
g = 0,
o = 0;
if (perms.su) d += 4;
if (perms.sg) d += 2;
if (perms.sb) d += 1;
if (perms.ru) u += 4;
if (perms.wu) u += 2;
if (perms.eu) u += 1;
if (perms.rg) g += 4;
if (perms.wg) g += 2;
if (perms.eg) g += 1;
if (perms.ro) o += 4;
if (perms.wo) o += 2;
if (perms.eo) o += 1;
return d.toString() + u.toString() + g.toString() + o.toString();
}
/**
* Given a permissions object dictionary, returns the file type.
*
* @param {Object} perms
* @returns {string}
*/
function ftFromPerms(perms) {
if (perms.d) return "Directory";
if (perms.sl) return "Symbolic link";
if (perms.np) return "Named pipe";
if (perms.s) return "Socket";
if (perms.cd) return "Character device";
if (perms.bd) return "Block device";
if (perms.dr) return "Door";
return "Regular file";
}
export default ParseUNIXFilePermissions;