diff --git a/src/core/operations/ParseUNIXFilePermissions.mjs b/src/core/operations/ParseUNIXFilePermissions.mjs new file mode 100644 index 00000000..829dda76 --- /dev/null +++ b/src/core/operations/ParseUNIXFilePermissions.mjs @@ -0,0 +1,323 @@ +/** + * @author n1474335 [n1474335@gmail.com] + * @copyright Crown Copyright 2016 + * @license Apache-2.0 + */ + +import Operation from "../Operation"; + +/** + * 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.

Input should be in either octal (e.g. 755) or textual (e.g. drwxr-xr-x) format."; + this.inputType = "string"; + this.outputType = "string"; + this.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 { + return "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;