CVE-2022-24771 (JavaScript, published 2022-03-18T14:15Z)
Description: value: Forge (also called `node-forge`) is a native implementation of Transport Layer Security in JavaScript. Prior to version 1.3.0, RSA PKCS#1 v1.5 signature verification code is lenient in checking the digest algorithm structure. This can allow a crafted structure that steals padding bytes and uses unchecked portion of the PKCS#1 encoded message to forge a signature when a low public exponent is being used. The issue has been addressed in `node-forge` version 1.3.0. There are currently no known workarounds.
Severity: MEDIUM (CVSS v3 base score: 7.5)
Weakness: CWE-347 \u2014 Improper Verification of Cryptographic Signature
The product does not verify, or incorrectly verifies, the cryptographic signature for data.
Repository: https://github.com/digitalbazaar/forge
Files changed:
CHANGELOG.md
lib/asn1.js
lib/oids.js
lib/rsa.js
tests/unit/rsa.js
Commit message: Fix signature verification issues.

**SECURITY**: Three RSA PKCS#1 v1.5 signature verification issues were
reported by Moosa Yahyazadeh (moosa-yahyazadeh@uiowa.edu):

- Leniency in checking `digestAlgorithm` structure can lead to signature
  forgery.
  - The code is lenient in checking the digest algorithm structure. This can
    allow a crafted structure that steals padding bytes and uses unchecked
    portion of the PKCS#1 encoded message to forge a signature when a low
    public exponent is being used.
- Failing to check tailing garbage bytes can lead to signature forgery.
  - The code does not check for tailing garbage bytes after decoding a
    `DigestInfo` ASN.1 structure. This can allow padding bytes to be removed
    and garbage data added to forge a signature when a low public exponent is
    being used.
- Leniency in checking type octet.
  - `DigestInfo` is not properly checked for proper ASN.1 structure. This can
    lead to successful verification with signatures that contain invalid
    structures but a valid digest.

For more information, please see "Bleichenbacher's RSA signature forgery based
on implementation error" by Hal Finney:
https://mailarchive.ietf.org/arch/msg/openpgp/5rnE9ZRN1AokBVj3VqblGlP63QE/

Fixed with the following:

- [asn1] `fromDer` is now more strict and will default to ensuring all
  input bytes are parsed or throw an error. A new option `parseAllBytes`
  can disable this behavior.
  - **NOTE**: The previous behavior is being changed since it can lead
    to security issues with crafted inputs. It is possible that code
    doing custom DER parsing may need to adapt to this new behavior and
    optional flag.
- [rsa] Add and use a validator to check for proper structure of parsed
  ASN.1 `RSASSA-PKCS-v1_5` `DigestInfo` data. Additionally check that
  the hash algorithm identifier is a known value. An invalid
  `DigestInfo` or algorithm identifier will now cause an error to be
  thrown.
- [oid] Added `1.2.840.113549.2.2` / `md2` for hash algorithm checking.
- [tests] Tests were added for all of the reported issues. A private
  verify option was added to assist in checking multiple possible
  failures in the test data.


Vulnerable code:
  return _fromDer(bytes, bytes.length(), 0, options);
  key.verify = function(digest, signature, scheme) {
          var obj = asn1.fromDer(d);
          return digest === obj.value[1].value;

Fixed code:
### Security
- **SECURITY**: Three RSA PKCS#1 v1.5 signature verification issues were
  reported by Moosa Yahyazadeh (moosa-yahyazadeh@uiowa.edu).
  - Leniency in checking `digestAlgorithm` structure can lead to signature
    forgery.
    - The code is lenient in checking the digest algorithm structure. This can
      allow a crafted structure that steals padding bytes and uses unchecked
      portion of the PKCS#1 encoded message to forge a signature when a low
      public exponent is being used. For more information, please see
      ["Bleichenbacher's RSA signature forgery based on implementation
      error"](https://mailarchive.ietf.org/arch/msg/openpgp/5rnE9ZRN1AokBVj3VqblGlP63QE/)
      by Hal Finney.
  - Failing to check tailing garbage bytes can lead to signature forgery.
    - The code does not check for tailing garbage bytes after decoding a
      `DigestInfo` ASN.1 structure. This can allow padding bytes to be removed
      and garbage data added to forge a signature when a low public exponent is
      being used.  For more information, please see ["Bleichenbacher's RSA
      signature forgery based on implementation
      error"](https://mailarchive.ietf.org/arch/msg/openpgp/5rnE9ZRN1AokBVj3VqblGlP63QE/)
      by Hal Finney.
  - Leniency in checking type octet.
    - `DigestInfo` is not properly checked for proper ASN.1 structure. This can
      lead to successful verification with signatures that contain invalid
      structures but a valid digest.

- [asn1] `fromDer` is now more strict and will default to ensuring all input
  bytes are parsed or throw an error. A new option `parseAllBytes` can disable
  this behavior.
  - **NOTE**: The previous behavior is being changed since it can lead to
    security issues with crafted inputs. It is possible that code doing custom
    DER parsing may need to adapt to this new behavior and optional flag.
- [rsa] Add and use a validator to check for proper structure of parsed ASN.1
  `RSASSA-PKCS-v1_5` `DigestInfo` data. Additionally check that the hash
  algorithm identifier is a known value. An invalid `DigestInfo` or algorithm
  identifier will now cause an error to be thrown.

### Added
- [oid] Added `1.2.840.113549.2.2` / `md2` for hash algorithm checking.
 *          [parseAllBytes] true to ensure all bytes are parsed
 *            (default: true)
 * @throws Will throw an error for various malformed input conditions.
 *
      parseAllBytes: true,
      parseAllBytes: true,
  if(!('parseAllBytes' in options)) {
    options.parseAllBytes = true;
  }
  var byteCount = bytes.length();
  var value = _fromDer(bytes, bytes.length(), 0, options);
  if(options.parseAllBytes && bytes.length() !== 0) {
    var error = new Error('Unparsed DER bytes remain after ASN.1 parsing.');
    error.byteCount = byteCount;
    error.remaining = bytes.length();
    throw error;
  }
  return value;
_IN('1.2.840.113549.2.2', 'md2');
// validator for a DigestInfo structure
var digestInfoValidator = {
  name: 'DigestInfo',
  tagClass: asn1.Class.UNIVERSAL,
  type: asn1.Type.SEQUENCE,
  constructed: true,
  value: [{
    name: 'DigestInfo.DigestAlgorithm',
    tagClass: asn1.Class.UNIVERSAL,
    type: asn1.Type.SEQUENCE,
    constructed: true,
    value: [{
      name: 'DigestInfo.DigestAlgorithm.algorithmIdentifier',
      tagClass: asn1.Class.UNIVERSAL,
      type: asn1.Type.OID,
      constructed: false,
      capture: 'algorithmIdentifier'
    }, {
      // NULL paramters
      name: 'DigestInfo.DigestAlgorithm.parameters',
      tagClass: asn1.Class.UNIVERSAL,
      type: asn1.Type.NULL,
      constructed: false
    }]
  }, {
    // digest
    name: 'DigestInfo.digest',
    tagClass: asn1.Class.UNIVERSAL,
    type: asn1.Type.OCTETSTRING,
    constructed: false,
    capture: 'digest'
  }]
};

   * @param options optional verify options
   *          _parseAllDigestBytes testing flag to control parsing of all
   *            digest bytes. Unsupported and not for general usage.
   *            (default: true)
  key.verify = function(digest, signature, scheme, options) {
    if(options === undefined) {
      options = {
        _parseAllDigestBytes: true
      };
    }
    if(!('_parseAllDigestBytes' in options)) {
      options._parseAllDigestBytes = true;
    }
          var obj = asn1.fromDer(d, {
            parseAllBytes: options._parseAllDigestBytes
          });

          // validate DigestInfo
          var capture = {};
          var errors = [];
          if(!asn1.validate(obj, digestInfoValidator, capture, errors)) {
            var error = new Error(
              'ASN.1 object does not contain a valid RSASSA-PKCS1-v1_5 ' +
              'DigestInfo value.');
            error.errors = errors;
            throw error;
          }
          // check hash algorithm identifier
          // FIXME: add support to vaidator for strict value choices
          var oid = asn1.derToOid(capture.algorithmIdentifier);
          if(!(oid === forge.oids.md2 ||
            oid === forge.oids.md5 ||
            oid === forge.oids.sha1 ||
            oid === forge.oids.sha256 ||
            oid === forge.oids.sha384 ||
            oid === forge.oids.sha512)) {
            var error = new Error(
              'Unknown RSASSA-PKCS1-v1_5 DigestAlgorithm identifier.');
            error.oid = oid;
            throw error;
          }

          return digest === capture.digest;
var JSBN = require('../../lib/jsbn');

    describe('bad data', function() {
      // params for tests

      // public modulus / 256 bytes
      var N = new JSBN.BigInteger(
        'E932AC92252F585B3A80A4DD76A897C8B7652952FE788F6EC8DD640587A1EE56' +
        '47670A8AD4C2BE0F9FA6E49C605ADF77B5174230AF7BD50E5D6D6D6D28CCF0A8' +
        '86A514CC72E51D209CC772A52EF419F6A953F3135929588EBE9B351FCA61CED7' +
        '8F346FE00DBB6306E5C2A4C6DFC3779AF85AB417371CF34D8387B9B30AE46D7A' +
        '5FF5A655B8D8455F1B94AE736989D60A6F2FD5CADBFFBD504C5A756A2E6BB5CE' +
        'CC13BCA7503F6DF8B52ACE5C410997E98809DB4DC30D943DE4E812A47553DCE5' +
        '4844A78E36401D13F77DC650619FED88D8B3926E3D8E319C80C744779AC5D6AB' +
        'E252896950917476ECE5E8FC27D5F053D6018D91B502C4787558A002B9283DA7',
        16);

      // private exponent
      var d = new JSBN.BigInteger(
        '009b771db6c374e59227006de8f9c5ba85cf98c63754505f9f30939803afc149' +
        '8eda44b1b1e32c7eb51519edbd9591ea4fce0f8175ca528e09939e48f37088a0' +
        '7059c36332f74368c06884f718c9f8114f1b8d4cb790c63b09d46778bfdc4134' +
        '8fb4cd9feab3d24204992c6dd9ea824fbca591cd64cf68a233ad0526775c9848' +
        'fafa31528177e1f8df9181a8b945081106fd58bd3d73799b229575c4f3b29101' +
        'a03ee1f05472b3615784d9244ce0ed639c77e8e212ab52abddf4a928224b6b6f' +
        '74b7114786dd6071bd9113d7870c6b52c0bc8b9c102cfe321dac357e030ed6c5' +
        '80040ca41c13d6b4967811807ef2a225983ea9f88d67faa42620f42a4f5bdbe0' +
        '3b',
        16);

      // public exponent
      var e = new JSBN.BigInteger('3');

      // hash function
      // H = SHA-256 (OID = 0x608648016503040201)

      // message
      var m = 'hello world!';

      // to-be-signed RSA PKCS#1 v1.5 signature scheme input structure
      // I

      // signature value obtained by I^d mod N
      // S

      function _checkBadTailingGarbage(publicKey, S) {
        var md = MD.sha256.create();
        md.update(m);

        ASSERT.throws(function() {
          publicKey.verify(md.digest().getBytes(), S);
        }, {
          message: 'Unparsed DER bytes remain after ASN.1 parsing.'
        });
      }

      function _checkBadDigestInfo(publicKey, S, skipTailingGarbage) {
        var md = MD.sha256.create();
        md.update(m);

        ASSERT.throws(function() {
          publicKey.verify(md.digest().getBytes(), S, undefined, {
            _parseAllDigestBytes: !skipTailingGarbage
          });
        }, {
          message: 'ASN.1 object does not contain a valid RSASSA-PKCS1-v1_5 DigestInfo value.'
        });
      }

      it('should check DigestInfo structure', function() {
        var publicKey = RSA.setPublicKey(N, e);
        var S = UTIL.binary.hex.decode(
          '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');

        _checkBadDigestInfo(publicKey, S);
      });

      it('should check tailing garbage and DigestInfo [1]', function() {
        var publicKey = RSA.setPublicKey(N, e);
        var S = UTIL.binary.hex.decode(
          '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');

        _checkBadTailingGarbage(publicKey, S);
        _checkBadDigestInfo(publicKey, S, true);
      });

      it('should check tailing garbage and DigestIfno [2]', function() {
        var publicKey = RSA.setPublicKey(N, e);
        var S = UTIL.binary.hex.decode(
          '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');

        _checkBadTailingGarbage(publicKey, S);
        _checkBadDigestInfo(publicKey, S, true);
      });

      it('should check tailing garbage and DigestInfo [e=3]', function() {
        var N = new JSBN.BigInteger(
          '29438513389594867490232201282478838726734464161887801289068585100507839535636256317277708295678804401391394313946142335874609638666081950936114152574870224034382561784743283763961349980806819078028975594777103388280272392844112380900374508170221075553517641170327441791034393719271744724924194371070527213991317221667249077972700842199037403799480569910844701030644322616045408039715278394572328099192023924503077673178227614549351191204851805076359472439160130994385433568113626206477097769842080459156024112389406200687233341779381667082591421496870666931268548504674362230725756397511775557878046572472650613407143');
        var e = new JSBN.BigInteger('3');
        var publicKey = RSA.setPublicKey(N, e);

        var S = UTIL.binary.hex.decode(
          '0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000002853ccc2cd32a8d430dd3bde37e70782ac82cdb7bce3c044219b50aefd689c20d3b840299f28e2fde6c67c8a7f9e528ac222fae947a6dee0d812e3c3b3452171717396e8bedc3132d92d8317e3593642640d1431ef');

        _checkBadTailingGarbage(publicKey, S);
        _checkBadDigestInfo(publicKey, S, true);
      });

      it('should check tailing garbage and DigestInfo [e=5]', function() {
        var N = new JSBN.BigInteger(
          '29438513389594867490232201282478838726734464161887801289068585100507839535636256317277708295678804401391394313946142335874609638666081950936114152574870224034382561784743283763961349980806819078028975594777103388280272392844112380900374508170221075553517641170327441791034393719271744724924194371070527213991317221667249077972700842199037403799480569910844701030644322616045408039715278394572328099192023924503077673178227614549351191204851805076359472439160130994385433568113626206477097769842080459156024112389406200687233341779381667082591421496870666931268548504674362230725756397511775557878046572472650613407143');
        var e = new JSBN.BigInteger('5');
        var publicKey = RSA.setPublicKey(N, e);

        var S = UTIL.binary.hex.decode(
          '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');

        _checkBadTailingGarbage(publicKey, S);
        _checkBadDigestInfo(publicKey, S, true);
      });

      it('should check tailing garbage and DigestInfo [e=17]', function() {
        var N = new JSBN.BigInteger(
          '928365641661298526294114382771769657905695995680009680444002258089796055192245321020911051590379097587133341820043795407471021630328875171430160513961779154294247563032373839871165519961382202811828883364651574763124699947662060849683176689286181021501400261976653416725246403933613615758181648971537689642956474563961490989544033629566558036444831495046301215543198107208071526376318961481739278769122885031686763776874806317352741548232110892401401727195758835975800106904020775937891505819798776295294696516670437057465296389148672556848624501468669295285428387365416747516180652630054765393335211528084329716917821726670549155619986875030049107668205064454104328601041931972319966348825621299693193542460060799067674344247887198933507132592770898312271636011037138984729256515515185153334743685479709085410902269777563691615719884708908509618352792737826421059819474305949001978916949447029010362775778664826653636547333219983468955600305523140183269580452792812503399042201081785972707218144968460623663922470814889738564730816412201128810370324070680245854669130551872958017494277468722193869883705529583737211815974801292292728082721785855274147991979220001018156560009927148374995236030383474031418802554714043680969417015155298092390680188406177667101020936206754551985229636814788735090951246816765035721775759652424641736739668936540450232814857289312589998505627375553038062765493408460941597629291231866042662108291164359496334978563287523685872262509560463225096226739991402761266388226652661345282274508037924611589455395655512013078629375186805951823181371561289129616028768733583565439798508002546685505512478002960132511531323264596144585611962969372672455541953777622436993987703564293487820434112162562492086865147598436647725445230861246093950020099084994990632102506848190196407855705745530407617253129971665939853842224965079537303198339986953399517682750248394628026225887174258267456078564070387327653989505416943226163989004419377363130466566387761757272563996086708621913140580687414698126490572618509858141748692837570235128900627675422927964369356691123905362222855545719945605604307263252851081309622569225811979426856464673233875589085773616373798857001344093594417138323005260179781153950803127773817702016534081581157881295739782000814998795398671806283018844936919299070562538763900037469485135699677248580365379125702903186174995651938469412191388327852955727869345476087173047665259892129895247785416834855450881318585909376917039');
        var e = new JSBN.BigInteger('17');
        var publicKey = RSA.setPublicKey(N, e);

        var S = UTIL.binary.hex.decode(
          '00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001eb90acbec1bf590ba1e50960db8381fb5bdc363d46379d09956560a616b88616ce7fa4309dc45f47f5fa47d61bf66baa3d11732ce71768ded295f962');

        _checkBadTailingGarbage(publicKey, S);
        _checkBadDigestInfo(publicKey, S, true);
      });

      it('should check DigestInfo type octet [1]', function() {
        var publicKey = RSA.setPublicKey(N, e);
        var S = UTIL.binary.hex.decode(
          'd8298a199e1b6ac18f3c0067a004bd9ff7af87be6ad857d73cc3d24ef06195b82aaddb0194f8e61fc31453b9163062255e8baf9c480200d0991a5f764f63d5f6afd283b9cd6afe54f0b7f738707b4eb6b8807539bb627e74db87a50413ab18e504e37975aad1edc612bc8ecad53b81ea249deb5a2acc27e6419c61ab9acec6608f5ae6a2985ba0b6f42d831bc6cce4b044864154b935cf179967d129e0ad8eda9bfbb638121c3ff13c64d439632e62250d4be928a3deb112ef76a025c5d918051e601878eac0049fc9d82be9ae3475deb7ca515c830c20b91b7bedf2184fef66aea0bde62ccd1659afbfd1342322b095309451b1a87e007e640e368fb68a13c9');

        _checkBadDigestInfo(publicKey, S);
      });

      it('should check DigestInfo type octet [2]', function() {
        var publicKey = RSA.setPublicKey(N, e);
        var S = UTIL.binary.hex.decode(
          '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');

        _checkBadDigestInfo(publicKey, S);
      });
    });