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Add operation for parsing X.509 CRLs
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robinsandhu committed Aug 25, 2024
1 parent d635cca commit 03ff840
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1 change: 1 addition & 0 deletions src/core/config/Categories.json
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"name": "Public Key",
"ops": [
"Parse X.509 certificate",
"Parse X.509 CRL",
"Parse ASN.1 hex string",
"PEM to Hex",
"Hex to PEM",
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335 changes: 335 additions & 0 deletions src/core/operations/ParseX509CRL.mjs
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/**
* @author robinsandhu
* @copyright Crown Copyright 2024
* @license Apache-2.0
*/

import r from "jsrsasign";
import Operation from "../Operation.mjs";
import { formatDnObj } from "../lib/PublicKey.mjs";
import OperationError from "../errors/OperationError.mjs";

/**
* Parse X.509 CRL operation
*/
class ParseX509CRL extends Operation {

/**
* ParseX509CRL constructor
*/
constructor() {
super();

this.name = "Parse X.509 CRL";
this.module = "PublicKey";
this.description = "Parse Certificate Revocation List (CRL)";
this.infoURL = "https://wikipedia.org/wiki/Certificate_revocation_list";
this.inputType = "string";
this.outputType = "string";
this.args = [
{
"name": "Input format",
"type": "option",
"value": ["PEM"]
}
];
this.checks = [
{
"pattern": "^-+BEGIN X509 CRL-+\\r?\\n[\\da-z+/\\n\\r]+-+END X509 CRL-+\\r?\\n?$",
"flags": "i",
"args": ["PEM"]
}
];
}

/**
* @param {string} input
* @param {Object[]} args
* @returns {string} Human-readable description of a Certificate Revocation List (CRL).
*/
run(input, args) {
if (!input.length) {
return "No input";
}

const crl = new r.X509CRL(input);

let out = `Certificate Revocation List (CRL):
Version: ${crl.getVersion() === null ? "1 (0x0)" : "2 (0x1)"}
Signature Algorithm: ${crl.getSignatureAlgorithmField()}
Issuer:\n${formatDnObj(crl.getIssuer(), 8)}
Last Update: ${generalizedDateTimeToUTC(crl.getThisUpdate())}
Next Update: ${generalizedDateTimeToUTC(crl.getNextUpdate())}\n`;

if (crl.getParam().ext !== undefined) {
out += `\tCRL extensions:\n${formatCRLExtensions(crl.getParam().ext, 8)}\n`;
}

out += `Revoked Certificates:\n${formatRevokedCertificates(crl.getRevCertArray(), 4)}
Signature Value:\n${formatCRLSignature(crl.getSignatureValueHex(), 8)}`;

return out;
}
}

/**
* Generalized date time string to UTC.
* @param {string} datetime
* @returns UTC datetime string.
*/
function generalizedDateTimeToUTC(datetime) {
// Ensure the string is in the correct format
if (!/^\d{12,14}Z$/.test(datetime)) {
throw new OperationError(`failed to format datetime string ${datetime}`);
}

// Extract components
let centuary = "20";
if (datetime.length === 15) {
centuary = datetime.substring(0, 2);
datetime = datetime.slice(2);
}
const year = centuary + datetime.substring(0, 2);
const month = datetime.substring(2, 4);
const day = datetime.substring(4, 6);
const hour = datetime.substring(6, 8);
const minute = datetime.substring(8, 10);
const second = datetime.substring(10, 12);

// Construct ISO 8601 format string
const isoString = `${year}-${month}-${day}T${hour}:${minute}:${second}Z`;

// Parse using standard Date object
const isoDateTime = new Date(isoString);

return isoDateTime.toUTCString();
}

/**
* Format CRL extensions.
* @param {r.ExtParam[] | undefined} extensions
* @param {Number} indent
* @returns Formatted string detailing CRL extensions.
*/
function formatCRLExtensions(extensions, indent) {
if (Array.isArray(extensions) === false || extensions.length === 0) {
return indentString(`No CRL extensions.`, indent);
}

let out = ``;

extensions.sort((a, b) => {
if (!Object.hasOwn(a, "extname") || !Object.hasOwn(b, "extname")) {
return 0;
}
if (a.extname < b.extname) {
return -1;
} else if (a.extname === b.extname) {
return 0;
} else {
return 1;
}
});

extensions.forEach((ext) => {
if (!Object.hasOwn(ext, "extname")) {
throw new OperationError(`CRL entry extension object missing 'extname' key: ${ext}`);
}
switch (ext.extname) {
case "authorityKeyIdentifier":
out += `X509v3 Authority Key Identifier:\n`;
if (Object.hasOwn(ext, "kid")) {
out += `\tkeyid:${colonDelimitedHexFormatString(ext.kid.hex.toUpperCase())}\n`;
}
if (Object.hasOwn(ext, "issuer")) {
out += `\tDirName:${ext.issuer.str}\n`;
}
if (Object.hasOwn(ext, "sn")) {
out += `\tserial:${colonDelimitedHexFormatString(ext.sn.hex.toUpperCase())}\n`;
}
break;
case "cRLDistributionPoints":
out += `X509v3 CRL Distribution Points:\n`;
ext.array.forEach((distPoint) => {
out += `\tFull Name:\n`;
distPoint.dpname.full.forEach((name) => {
if (Object.hasOwn(name, "ip")) {
out += `\t\tIP:${name.ip}\n`;
}
if (Object.hasOwn(name, "dns")) {
out += `\t\tDNS:${name.dns}\n`;
}
if (Object.hasOwn(name, "uri")) {
out += `\t\tURI:${name.uri}\n`;
}
if (Object.hasOwn(name, "rfc822")) {
out += `\t\tEMAIL:${name.rfc822}\n`;
}
});
});
break;
case "cRLNumber":
if (!Object.hasOwn(ext, "num")) {
throw new OperationError(`'cRLNumber' CRL entry extension missing 'num' key: ${ext}`);
}
out += `X509v3 CRL Number:\n\t${ext.num.hex.toUpperCase()}\n`;
break;
default:
out += `${ext.extname}:\n`;
out += `\tUnsupported CRL extension. Try openssl CLI.\n`;
break;
}
});

return indentString(chop(out), indent);
}

/**
* Colon-delimited hex formatted output.
* @param {string} hexString Hex String
* @returns String representing input hex string with colon delimiter.
*/
function colonDelimitedHexFormatString(hexString) {
if (hexString.length % 2 !== 0) {
hexString = "0" + hexString;
}

return chop(hexString.replace(/(..)/g, "$&:"));
}

/**
* Format revoked certificates array
* @param {r.RevokedCertificate[] | null} revokedCertificates
* @param {Number} indent
* @returns Multi-line formatted string output of revoked certificates array
*/
function formatRevokedCertificates(revokedCertificates, indent) {
if (Array.isArray(revokedCertificates) === false || revokedCertificates.length === 0) {
return indentString("No Revoked Certificates.", indent);
}

let out=``;

revokedCertificates.forEach((revCert) => {
if (!Object.hasOwn(revCert, "sn") || !Object.hasOwn(revCert, "date")) {
throw new OperationError("invalid revoked certificate object, missing either serial number or date");
}

out += `Serial Number: ${revCert.sn.hex.toUpperCase()}
Revocation Date: ${generalizedDateTimeToUTC(revCert.date)}\n`;
if (Object.hasOwn(revCert, "ext") && Array.isArray(revCert.ext) && revCert.ext.length !== 0) {
out += `\tCRL entry extensions:\n${indentString(formatCRLEntryExtensions(revCert.ext), 2*indent)}\n`;
}
});

return indentString(chop(out), indent);
}

/**
* Format CRL entry extensions.
* @param {Object[]} exts
* @returns Formatted multi-line string describing CRL entry extensions.
*/
function formatCRLEntryExtensions(exts) {
let out = ``;

const crlReasonCodeToReasonMessage = {
0: "Unspecified",
1: "Key Compromise",
2: "CA Compromise",
3: "Affiliation Changed",
4: "Superseded",
5: "Cessation Of Operation",
6: "Certificate Hold",
8: "Remove From CRL",
9: "Privilege Withdrawn",
10: "AA Compromise",
};

const holdInstructionOIDToName = {
"1.2.840.10040.2.1": "Hold Instruction None",
"1.2.840.10040.2.2": "Hold Instruction Call Issuer",
"1.2.840.10040.2.3": "Hold Instruction Reject",
};

exts.forEach((ext) => {
if (!Object.hasOwn(ext, "extname")) {
throw new OperationError(`CRL entry extension object missing 'extname' key: ${ext}`);
}
switch (ext.extname) {
case "cRLReason":
if (!Object.hasOwn(ext, "code")) {
throw new OperationError(`'cRLReason' CRL entry extension missing 'code' key: ${ext}`);
}
out += `X509v3 CRL Reason Code:
${Object.hasOwn(crlReasonCodeToReasonMessage, ext.code) ? crlReasonCodeToReasonMessage[ext.code] : `invalid reason code: ${ext.code}`}\n`;
break;
case "2.5.29.23": // Hold instruction
out += `Hold Instruction Code:\n\t${Object.hasOwn(holdInstructionOIDToName, ext.extn.oid) ? holdInstructionOIDToName[ext.extn.oid] : `${ext.extn.oid}: unknown hold instruction OID`}\n`;
break;
case "2.5.29.24": // Invalidity Date
out += `Invalidity Date:\n\t${generalizedDateTimeToUTC(ext.extn.gentime.str)}\n`;
break;
default:
out += `${ext.extname}:\n`;
out += `\tUnsupported CRL entry extension. Try openssl CLI.\n`;
break;
}
});

return chop(out);
}

/**
* Format CRL signature.
* @param {String} sigHex
* @param {Number} indent
* @returns String representing hex signature value formatted on multiple lines.
*/
function formatCRLSignature(sigHex, indent) {
if (sigHex.length % 2 !== 0) {
sigHex = "0" + sigHex;
}

return indentString(formatMultiLine(chop(sigHex.replace(/(..)/g, "$&:"))), indent);
}

/**
* Format string onto multiple lines.
* @param {string} longStr
* @returns String as a multi-line string.
*/
function formatMultiLine(longStr) {
const lines = [];

for (let remain = longStr ; remain !== "" ; remain = remain.substring(54)) {
lines.push(remain.substring(0, 54));
}

return lines.join("\n");
}

/**
* Indent a multi-line string by n spaces.
* @param {string} input String
* @param {number} spaces How many leading spaces
* @returns Indented string.
*/
function indentString(input, spaces) {
const indent = " ".repeat(spaces);
return input.replace(/^/gm, indent);
}

/**
* Remove last character from a string.
* @param {string} s String
* @returns Chopped string.
*/
function chop(s) {
if (s.length < 1) {
return s;
}
return s.substring(0, s.length - 1);
}

export default ParseX509CRL;

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