v1.2.6: Use native BigInt to generate dp and dq vals for RSA

README.md

@@ -5,19 +5,23 @@ and convert it into a public JWK.
 
 Works for RSA and ECDSA public keys.
 
-Features
-========
+# Features
 
 &lt; 100 lines of code | <1kb gzipped | 1.8kb minified | 3.1kb with comments
 
-* [x] SSH Public Keys
-* [x] RSA Public Keys
+* [x] SSH Public Keys ([RFC 4253](https://coolaj86.com/articles/the-ssh-public-key-format/))
+  * fingerprint
+* [x] OpenSSH Private Keys
+* [x] RSA
+  * 2048, 3072, 4096
 * [x] EC Public Keys
   * P-256 (prime256v1, secp256r1)
   * P-384 (secp384r1)
 * [x] Browser Version
   * [Bluecrypt SSH to JWK](https://git.coolaj86.com/coolaj86/bluecrypt-ssh-to-jwk.js)
 
+Note: Lines of code have increased by about 2x since adding private key support.
+
 ### Need JWK to SSH? SSH to PEM?
 
 Try one of these:
@@ -28,9 +32,12 @@ Try one of these:
 
 ### Need SSH Private Keys?
 
-SSH private keys are just normal PEM files,
+Many SSH private keys are just normal PEM files,
 so you can use Eckles or Rasha, as mentioned above.
 
+As for the [OpenSSH-specific Private Keys](https://coolaj86.com/articles/the-openssh-private-key-format/),
+both EC and RSA are fully supported.
+
 # CLI
 
 You can install `ssh-to-jwk` and use it from command line:
@@ -43,22 +50,43 @@ npm install -g ssh-to-jwk
 ssh-to-jwk ~/.ssh/id_rsa.pub
 ```
 
+```bash
+ssh-to-jwk ~/.ssh/id_rsa
+```
+
 # Usage
 
 You can also use it from JavaScript:
 
+**SSH to JWK**
+
 ```js
 var fs = require('fs');
 var sshtojwk = require('ssh-to-jwk');
+var ssh;
 
-var pub = fs.readFileSync("./id_rsa.pub");
-var ssh = sshtojwk.parse(pub);
+ssh = sshtojwk.parse({ pub: fs.readFileSync("./id_rsa.pub") });
+console.info(ssh.jwk);
 
+// For OpenSSH PEMs only, use Rasha for standard RSA or Eckles for standard EC
+ssh = sshtojwk.parse({ pem: fs.readFileSync("./id_rsa") });
 console.info(ssh.jwk);
 ```
 
-Legal
------
+**SSH Fingerprint**
+
+```js
+var fs = require('fs');
+var sshtojwk = require('ssh-to-jwk');
+var pub = fs.readFileSync("./id_rsa.pub");
+
+sshtojwk.fingerprint({ pub: pub }).then(function (fingerprint) {
+  console.info(fingerprint);
+  // SHA256:yCB62vBVsOwqksgYwy/WDbaMF2PhPijAwcrlzmrxfko
+});
+```
+
+# Legal
 
 [ssh-to-jwk.js](https://git.coolaj86.com/coolaj86/ssh-to-jwk.js) |
 MPL-2.0 |

bin/ssh-to-jwk.js

@@ -6,12 +6,27 @@ var path = require('path');
 var sshtojwk = require('../index.js');
 
 var pubfile = process.argv[2];
+var pub = process.argv[3];
 
 if (!pubfile) {
   pubfile = path.join(require('os').homedir(), '.ssh/id_rsa.pub');
 }
 
 var buf = fs.readFileSync(pubfile);
-var ssh = sshtojwk.parse(buf.toString('ascii'));
+var txt = buf.toString('ascii');
+var opts = { public: 'public' === pub };
+var ssh;
 
-console.info(JSON.stringify(ssh.jwk, null, 2));
+if ('-' === txt[0]) {
+  opts.pem = txt;
+} else {
+  opts.pub = txt;
+}
+
+ssh = sshtojwk.parse(opts);
+
+// Finally! https://superuser.com/a/714195
+sshtojwk.fingerprint(ssh).then(function (fingerprint) {
+  console.warn('The key fingerprint is:\n' + fingerprint + ' ' + ssh.comment);
+  console.info(JSON.stringify(ssh.jwk, null, 2));
+});

fixtures/privkey-ec-p256.jwk.json

@@ -0,0 +1,7 @@
+{
+  "kty": "EC",
+  "crv": "P-256",
+  "d": "iYydo27aNGO9DBUWeGEPD8oNi1LZDqfxPmQlieLBjVQ",
+  "x": "IT1SWLxsacPiE5Z16jkopAn8_-85rMjgyCokrnjDft4",
+  "y": "mP2JwOAOdMmXuwpxbKng3KZz27mz-nKWIlXJ3rzSGMo"
+}

fixtures/privkey-ec-p256.openssh.pem

@@ -0,0 +1,9 @@
+-----BEGIN OPENSSH PRIVATE KEY-----
+b3BlbnNzaC1rZXktdjEAAAAABG5vbmUAAAAEbm9uZQAAAAAAAAABAAAAaAAAABNlY2RzYS
+1zaGEyLW5pc3RwMjU2AAAACG5pc3RwMjU2AAAAQQQhPVJYvGxpw+ITlnXqOSikCfz/7zms
+yODIKiSueMN+3pj9icDgDnTJl7sKcWyp4Nymc9u5s/pyliJVyd680hjKAAAAqGJjanNiY2
+pzAAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBCE9Uli8bGnD4hOW
+deo5KKQJ/P/vOazI4MgqJK54w37emP2JwOAOdMmXuwpxbKng3KZz27mz+nKWIlXJ3rzSGM
+oAAAAhAImMnaNu2jRjvQwVFnhhDw/KDYtS2Q6n8T5kJYniwY1UAAAADnJvb3RAbG9jYWxo
+b3N0AQ==
+-----END OPENSSH PRIVATE KEY-----

fixtures/privkey-ec-p384.jwk.json

@@ -0,0 +1,7 @@
+{
+  "kty": "EC",
+  "crv": "P-384",
+  "d": "XlyuCEWSTTS8U79O_Mz05z18vh4kb10szvu_7pdXuGWV6lfEyPExyUYWsA6A2kdV",
+  "x": "2zEU0bKCa7ejKLIJ8oPGnLhqhxyiv4_w38K2a0SPC6dsSd9_glNJ8lcqv0sff5Gb",
+  "y": "VD4jnu83S6scn6_TeAj3EZOREGbOs6dzoVpaugn-XQMMyC9O4VLbDDFGBZTJlMsb"
+}

fixtures/privkey-ec-p384.openssh.pem

@@ -0,0 +1,10 @@
+-----BEGIN OPENSSH PRIVATE KEY-----
+b3BlbnNzaC1rZXktdjEAAAAABG5vbmUAAAAEbm9uZQAAAAAAAAABAAAAiAAAABNlY2RzYS
+1zaGEyLW5pc3RwMzg0AAAACG5pc3RwMzg0AAAAYQTbMRTRsoJrt6Mosgnyg8acuGqHHKK/
+j/DfwrZrRI8Lp2xJ33+CU0nyVyq/Sx9/kZtUPiOe7zdLqxyfr9N4CPcRk5EQZs6zp3OhWl
+q6Cf5dAwzIL07hUtsMMUYFlMmUyxsAAADYYmNqc2JjanMAAAATZWNkc2Etc2hhMi1uaXN0
+cDM4NAAAAAhuaXN0cDM4NAAAAGEE2zEU0bKCa7ejKLIJ8oPGnLhqhxyiv4/w38K2a0SPC6
+dsSd9/glNJ8lcqv0sff5GbVD4jnu83S6scn6/TeAj3EZOREGbOs6dzoVpaugn+XQMMyC9O
+4VLbDDFGBZTJlMsbAAAAMF5crghFkk00vFO/TvzM9Oc9fL4eJG9dLM77v+6XV7hllepXxM
+jxMclGFrAOgNpHVQAAAA5yb290QGxvY2FsaG9zdAEC
+-----END OPENSSH PRIVATE KEY-----

fixtures/privkey-rsa-2048.jwk.json

@@ -0,0 +1,11 @@
+{
+  "kty": "RSA",
+  "n": "m2ttVBxPlWw06ZmGBWVDlfjkPAJ4DgnY0TrDwtCohHzLxGhDNzUJefLukC-xu0LBKylYojT5vTkxaOhxeSYo31syu4WhxbkTBLICOFcCGMob6pSQ38P8LdAIlb0pqDHxEJ9adWomjuFf0SUhN1cP7s9m8Yk9trkpEqjskocn2BOnTB57qAZM6-I70on0_iDZm7-jcqOPgADAmbWHhy67BXkk4yy_YzD4yOGZFXZcNp915_TW5bRd__AKPHUHxJasPiyEFqlNKBR2DSD-LbX5eTmzCh2ikrwTMja7mUdBJf2bK3By5AB0Qi49OykUCfNZeQlEz7UNNj9RGps_50-CNw",
+  "e": "AQAB",
+  "d": "Cpfo7Mm9Nu8YMC_xrZ54W9mKHPkCG9rZ93Ds9PNp-RXUgb-ljTbFPZWsYxGNKLllFz8LNosr1pT2ZDMrwNk0Af1iWNvD6gkyXaiQdCyiDPSBsJyNv2LJZon-e85X74nv53UlIkmo9SYxdLz2JaJ-iIWEe8Qh-7llLktrTJV_xr98_tbhgSppz_IeOymq3SEZaQHM8pTU7w7XvCj2pb9r8fN0M0XcgWZIaf3LGEfkhF_WtX67XJ0C6-LbkT51jtlLRNGX6haGdscXS0OWWjKOJzKGuV-NbthEn5rmRtVnjRZ3yaxQ0ud8vC-NONn7yvGUlOur1IdDzJ_YfHPt9sHMQQ",
+  "p": "ynG-t9HwKCN3MWRYFdnFzi9-02Qcy3p8B5pu3ary2E70hYn2pHlUG2a9BNE8c5xHQ3Hx43WoWf6s0zOunPV1G28LkU_UYEbAtPv_PxSmzpQp9n9XnYvBLBF8Y3z7gxgLn1vVFNARrQdRtj87qY3aw7E9S4DsGcAarIuOT2TsTCE",
+  "q": "xIkAjgUzB1zaUzJtW2Zgvp9cYYr1DmpH30ePZl3c_8397_DZDDo46fnFYjs6uPa03HpmKUnbjwr14QHlfXlntJBEuXxcqLjkdKdJ4ob7xueLTK4suo9V8LSrkLChVxlZQwnFD2E5ll0sVeeDeMJHQw38ahSrBFEVnxjpnPh1Q1c",
+  "dp": "tzDGjECFOU0ehqtuqhcuT63a7h8hj19-7MJqoFwY9HQ-ALkfXyYLXeBSGxHbyiIYuodZg6LsfMNgUJ3r3Eyhc_nAVfYPEC_2IdAG4WYmq7iXYF9LQV09qEsKbFykm7QekE3hO7wswo5k-q2tp3ieBYdVGAXJoGOdv5VpaZ7B1QE",
+  "dq": "kh5dyDk7YCz7sUFbpsmuAeuPjoH2ghooh2u3xN7iUVmAg-ToKjwbVnG5-7eXiC779rQVwnrD_0yh1AFJ8wjRPqDIR7ObXGHikIxT1VSQWqiJm6AfZzDsL0LUD4YS3iPdhob7-NxLKWzqao_u4lhnDQaX9PKa12HFlny6K1daL48",
+  "qi": "AlHWbx1gp6Z9pbw_1hlS7HuXAgWoX7IjbTUelldf4gkriDWLOrj3QCZcO4ZvZvEwJhVlsny9LO8IkbwGJEL6cXraK08ByVS2mwQyflgTgGNnpzixyEUL_mrQLx6y145FHcxfeqNInMhep-0Mxn1D5nlhmIOgRApS0t9VoXtHhFU"
+}

fixtures/privkey-rsa-2048.openssh.pem

@@ -0,0 +1,27 @@
+-----BEGIN OPENSSH PRIVATE KEY-----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+-----END OPENSSH PRIVATE KEY-----

fixtures/pub-ec-p256.ssh.pub

@@ -0,0 +1 @@
+ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBH1Zk94FK+LGSGNA6H3IJdeUTHkI30zKH3gIknWuKB/zr3eBz3QeZqEhHmgwYfCWoyhLuQqtHD7gqnGqwXssa/E= aj@bowie.local

fixtures/pub-ec-p384.ssh.pub

@@ -0,0 +1 @@
+ecdsa-sha2-nistp384 AAAAE2VjZHNhLXNoYTItbmlzdHAzODQAAAAIbmlzdHAzODQAAABhBMM1wvONZSobkf6CtT9n5E06y+ofhXmpTVSWRTOpMiZi+bsKViBi1eptF4LMufUT4M5DDU3V/kT9iM8124uWSWwS/ernmTsENNOI2TlzXkKkJshXh5Z4tFIVIkEZAeW/6w== aj@bowie.local

fixtures/pub-rsa-2048.ssh.pub

@@ -0,0 +1 @@
+ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDTNGUXvKQQ2sbdXdILzeI7u60ziBDHqCbrYxUkdro0LA8SqimkQexHKd9SBVvrxNm3l1LsCRmeIgrxlhwuptsygK80rRX5Jit2DCRP62tyMBIEIqLxAksMEW1z6M3XIdIj2jWkL6ei6Qver03JWt4TfxZG94axSPxPaHYf6Psb+lZnMfYrWXtVD9hJA6vQjKNqmpUo1I2dWq6e6F3Oepejfu9Cz1yMnEsNJG3COubJSXUkEdsJYSrW3wfUnMPBrlnjs8uP4NBTik+5SHmpb+pU3+2DjgC4tsnTIkiusaLIp/qJmS+X18pFzRCMy2jfX1QeHMPsXnBSvdfyIdZfIVs5 aj@bowie.local

lib/encoding.js

@@ -10,6 +10,20 @@ Enc.base64ToBuf = function (str) {
   return Buffer.from(str, 'base64');
 };
 
+Enc.base64ToHex = function (str) {
+  return Buffer.from(str, 'base64').toString('hex');
+};
+
+Enc.base64ToUrlBase64 = function (b64) {
+  return b64.replace(/\+/g, '-').replace(/\//g, '_').replace(/=/g, '');
+};
+
+Enc.bnToUrlBase64 = function (bn) {
+  var hex = bn.toString(16);
+  if (hex.length % 2) { hex = '0' + hex; }
+  return Enc.base64ToUrlBase64(Buffer.from(hex, 'hex').toString('base64'));
+};
+
 Enc.bufToBase64 = function (u8) {
   return Buffer.from(u8).toString('base64');
 };
@@ -23,6 +37,5 @@ Enc.bufToHex = function (u8) {
 };
 
 Enc.bufToUrlBase64 = function (u8) {
-  return Enc.bufToBase64(u8)
-    .replace(/\+/g, '-').replace(/\//g, '_').replace(/=/g, '');
+  return Enc.base64ToUrlBase64(Enc.bufToBase64(u8));
 };

lib/pem.js

@@ -0,0 +1,28 @@
+'use strict';
+
+var PEM = module.exports;
+var Enc = require('./encoding.js');
+
+PEM.parseBlock = function pemToDer(pem) {
+  var lines = pem.trim().split(/\n/);
+  var end = lines.length - 1;
+  var head = lines[0].match(/-----BEGIN (.*)-----/);
+  var foot = lines[end].match(/-----END (.*)-----/);
+
+  if (head) {
+    lines = lines.slice(1, end);
+    head = head[1];
+    if (head !== foot[1]) {
+      throw new Error("headers and footers do not match");
+    }
+  }
+
+  return { type: head, bytes: Enc.base64ToBuf(lines.join('')) };
+};
+
+PEM.packBlock = function (opts) {
+  return '-----BEGIN ' + opts.type + '-----\n'
+    + Enc.bufToBase64(opts.bytes).match(/.{1,64}/g).join('\n') + '\n'
+    + '-----END ' + opts.type + '-----'
+  ;
+};

lib/ssh-parser.js

@@ -1,57 +1,126 @@
 'use strict';
 
+/*global BigInt*/
 var SSH = module.exports;
 var Enc = require('./encoding.js');
+var PEM = require('./pem.js');
+var bnwarn = false;
 
-SSH.parse = function (ssh) {
-  ssh = ssh.split(/\s+/g);
-
-  var result = { type: ssh[0], jwk: null, comment: ssh[2] || '' };
-  var buf = Enc.base64ToBuf(ssh[1]);
-  var els = SSH.parseElements({ bytes: buf }).elements;
-  var typ = Enc.bufToBin(els[0]);
-  var len;
-
-  // RSA keys are all the same
-  if (SSH.types.rsa === typ) {
-    result.jwk = {
-      kty: 'RSA'
-    , n: Enc.bufToUrlBase64(els[2])
-    , e: Enc.bufToUrlBase64(els[1])
-    };
-    return result;
+SSH.parse = function (opts) {
+  var pub = opts.pem || opts.pub || opts;
+  var ssh = SSH.parseBlock(pub);
+  if ('OPENSSH PRIVATE KEY' === ssh.type) {
+    ssh = SSH.parsePrivateElements(ssh);
+    if (7 === ssh.elements.length) {
+      // RSA Private Keys have the `e` and `n` swapped (which is actually more normal)
+      // but we have to reswap them to make them consistent with the public key format
+      ssh.elements.splice(1, 0, ssh.elements.splice(2 ,1)[0]);
+    }
+    if (opts.public) {
+      ssh.elements = ssh.elements.slice(0, 3);
     }
-
-  // EC keys are each different
-  if (SSH.types.p256 === typ) {
-    len = 32;
-    result.jwk = { kty: 'EC', crv: 'P-256' };
-  } else if (SSH.types.p384 === typ) {
-    len = 48;
-    result.jwk = { kty: 'EC', crv: 'P-384' };
   } else {
-    throw new Error("Unsupported ssh public key type: "
-      + Enc.bufToBin(els[0]));
+    ssh.elements = SSH.parseElements(ssh.bytes);
   }
 
-  // els[1] is just a repeat of a subset of els[0]
-  var x = els[2].slice(1, 1 + len);
-  var y = els[2].slice(1 + len, 1 + len + len);
-
-  // I don't think EC keys use 0x00 padding, but just in case
-  while (0x00 === x[0]) { x = x.slice(1); }
-  while (0x00 === y[0]) { y = y.slice(1); }
-
-  result.jwk.x = Enc.bufToUrlBase64(x);
-  result.jwk.y = Enc.bufToUrlBase64(y);
-
-  return result;
+  //delete ssh.bytes;
+  return SSH.parsePublicKey(ssh);
 };
 
-SSH.parseElements = function (ssh) {
+/*global Promise*/
+SSH.fingerprint = function (opts) {
+  var ssh;
+  if (opts.bytes) {
+    ssh = opts;
+  } else {
+    ssh = SSH.parseBlock(opts.pub);
+  }
+  // for browser compat
+  return Promise.resolve().then(function () {
+    return 'SHA256:' + require('crypto').createHash('sha256')
+      .update(ssh.bytes).digest('base64').replace(/=+$/g, '');
+  });
+};
+
+SSH.parseBlock = function (ssh) {
+  if (/^-----BEGIN OPENSSH PRIVATE KEY-----/.test(ssh)) {
+    return PEM.parseBlock(ssh);
+  }
+  ssh = ssh.split(/\s+/g);
+
+  return {
+    type: ssh[0]
+  , bytes: Enc.base64ToBuf(ssh[1])
+  , comment: ssh[2]
+  };
+};
+
+SSH.parsePrivateElements = function (ssh) {
+  // https://coolaj86.com/articles/the-openssh-private-key-format/
   var buf = ssh.bytes;
   var fulllen = buf.byteLength || buf.length;
   var offset = (buf.byteOffset || 0);
+  var dv = new DataView(buf.buffer.slice(offset, offset + fulllen));
+  var index = 0;
+  var padlen = 0;
+  var len;
+  var pub;
+
+  // The last byte will be either
+  //   * a non-printable pad character
+  //   * a printable comment character
+  function lastByteIsPad() {
+    var n = ssh.bytes[(ssh.bytes.bytesLength || ssh.bytes.length) - 1];
+    return n >= 0x01 && n <= 0x07;
+  }
+  while (lastByteIsPad()) {
+    padlen += 1;
+    len = (ssh.bytes.bytesLength || ssh.bytes.length);
+    ssh.bytes = ssh.bytes.slice(0, len - 1);
+  }
+
+  //  o  p  e  n  s  s  h  -  k  e  y  -  v  1  NULL
+  // 6f 70 65 6e 73 73 68 2d 6b 65 79 2d 76 31 00
+  // 15 characters
+  // 4-byte len, "none" (encryption)
+  // 4-byte len, "none" (kdfname)
+  if ('none' !== Enc.bufToBin(ssh.bytes.slice(15 + 8 + 4, 15 + 8 + 8))) {
+    throw new Error("Key is either encrypted (not yet supported), corrupt, or not openssh-key-v1");
+  }
+  if (padlen >= 8) {
+    throw new Error("Padding length should be between 0 and 7, not '" + padlen + "'."
+      + " Probably not an ssh private key.");
+  }
+  // 4-byte len, nil (kdf)
+  // 4-byte number of keys
+  index += 15 + 8 + 8 + 4 + 4;
+
+  // length of public key
+  len = dv.getUint32(index, false);
+  // throw away public key (it's in the private key)
+  index += 4 + len;
+  pub = ssh.bytes.slice(index - len, index);
+
+  // length of dummy checksum + private key + padding
+  len = dv.getUint32(index, false) - padlen;
+  // throw away dummy checksum
+  index += 4 + 8;
+
+  ssh.elements = SSH.parseElements(ssh.bytes.slice(index, index + (len - 8)));
+  index += Array.prototype.reduce.call(ssh.elements, function (el, sum) {
+    // 32-bit len + element len
+    return 4 + (el.byteLength || el.length) + sum;
+  }, 0);
+
+  // comment will exist, even if it's an empty string
+  ssh.comment = Enc.bufToBin(ssh.elements.pop());
+  ssh.bytes = pub;
+  return ssh;
+};
+SSH.parseElements = function (buf) {
+  var fulllen = buf.byteLength || buf.length;
+  // Note: node has weird offsets
+  var offset = (buf.byteOffset || 0);
   var i = 0;
   var index = 0;
   // using dataview to be browser-compatible (I do want _some_ code reuse)
@@ -65,6 +134,7 @@ SSH.parseElements = function (ssh) {
     if (i > 15) { throw new Error("15+ elements, probably not a public ssh key"); }
     len = dv.getUint32(index, false);
     index += 4;
+    if (0 === len) { continue; }
     el = buf.slice(index, index + len);
     // remove BigUInt '00' prefix
     if (0x00 === el[0]) {
@@ -74,12 +144,90 @@ SSH.parseElements = function (ssh) {
     index += len;
   }
   if (fulllen !== index) {
-    throw new Error(els.map(function (b) {
+    throw new Error("invalid ssh public key length \n" + els.map(function (b) {
       return Enc.bufToHex(b);
-    }).join('\n') + "invalid ssh public key length");
+    }).join('\n'));
   }
 
-  ssh.elements = els;
+  return els;
+};
+
+SSH.parsePublicKey = function (ssh) {
+  var els = ssh.elements;
+  var typ = Enc.bufToBin(els[0]);
+  var len;
+
+  // RSA keys are all the same
+  if (SSH.types.rsa === typ) {
+    if (3 === els.length) {
+      ssh.jwk = {
+        kty: 'RSA'
+      , n: Enc.bufToUrlBase64(els[2])
+      , e: Enc.bufToUrlBase64(els[1])
+      };
+    } else {
+      ssh.jwk = {
+        kty: 'RSA'
+      , n: Enc.bufToUrlBase64(els[2])
+      , e: Enc.bufToUrlBase64(els[1])
+      , d: Enc.bufToUrlBase64(els[3])
+      , p: Enc.bufToUrlBase64(els[5])
+      , q: Enc.bufToUrlBase64(els[6])
+      , dp: 0
+      , dq: 0
+      , qi: Enc.bufToUrlBase64(els[4])
+      };
+      if ('undefined' !== typeof BigInt) {
+        // BigInt doesn't use new
+        /*jshint newcap: false*/
+        // d mod (p - 1)
+        ssh.jwk.dp = Enc.bnToUrlBase64(BigInt('0x' + Enc.base64ToHex(ssh.jwk.d))
+          % (BigInt('0x' + Enc.base64ToHex(ssh.jwk.p)) - BigInt(1)));
+        ssh.jwk.dq = Enc.bnToUrlBase64(BigInt('0x' + Enc.base64ToHex(ssh.jwk.d))
+          % (BigInt('0x' + Enc.base64ToHex(ssh.jwk.q)) - BigInt(1)));
+      } else {
+        if (!bnwarn) {
+          bnwarn = true;
+          // TODO maybe conditionally bring in BigInt polyfill?
+          console.warn("ssh-to-jwk.js: Your version of node is outdated doesn't support BigInt");
+          console.log("JWKs will be missing `dp` and `dq` values. Update or use a BigInt polyfill.");
+        }
+        delete ssh.jwk.dp;
+        delete ssh.jwk.dq;
+      }
+    }
+    return ssh;
+  }
+
+  // EC keys are each different
+  if (SSH.types.p256 === typ) {
+    len = 32;
+    ssh.jwk = { kty: 'EC', crv: 'P-256' };
+  } else if (SSH.types.p384 === typ) {
+    len = 48;
+    ssh.jwk = { kty: 'EC', crv: 'P-384' };
+  } else {
+    throw new Error("Unsupported ssh public key type: "
+      + Enc.bufToBin(els[0]));
+  }
+
+  // els[1] is just a repeat of a subset of els[0]
+  var x = els[2].slice(1, 1 + len);
+  var y = els[2].slice(1 + len, 1 + len + len);
+  var d;
+
+  // I don't think EC keys use 0x00 padding, but just in case
+  while (0x00 === x[0]) { x = x.slice(1); }
+  while (0x00 === y[0]) { y = y.slice(1); }
+
+  if (els[3]) {
+    d = els[3];
+    while (0x00 === d[0]) { d = d.slice(1); }
+    ssh.jwk.d = Enc.bufToUrlBase64(d);
+  }
+  ssh.jwk.x = Enc.bufToUrlBase64(x);
+  ssh.jwk.y = Enc.bufToUrlBase64(y);
+
   return ssh;
 };
 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "ssh-to-jwk",
-  "version": "1.0.2",
+  "version": "1.2.6",
   "description": "💯 SSH to JWK in a lightweight, zero-dependency library.",
   "homepage": "https://git.coolaj86.com/coolaj86/ssh-to-jwk.js",
   "main": "index.js",
@@ -29,6 +29,8 @@
     "RSA",
     "EC",
     "SSH",
+    "OpenSSH",
+    "fingerprint",
     "JWK",
     "ECDSA"
   ],