generates seemingly-valid EC and RSA CSRs

app.js

@@ -58,8 +58,10 @@
       , namedCurve: $('input[name="ec-crv"]:checked').value
       , modulusLength: $('input[name="rsa-len"]:checked').value
       };
+      var then = Date.now();
       console.log('opts', opts);
       Keypairs.generate(opts).then(function (results) {
+        console.log("Key generation time:", (Date.now() - then) + "ms");
         var pubDer;
         var privDer;
         if (/EC/i.test(opts.kty)) {
@@ -165,8 +167,9 @@
       var acme = accountStuff.acme;
 
       return Keypairs.generate({
-        kty: 'RSA'
+        kty: $('input[name="kty"]:checked').value
-      , modulusLength: 2048
+      , namedCurve: $('input[name="ec-crv"]:checked').value
+      , modulusLength: $('input[name="rsa-len"]:checked').value
       }).then(function (pair) {
         console.log('domain keypair:', pair);
         var domains = ($('.js-domains').value||'example.com').split(/[, ]+/g);

lib/csr-ec.js

@@ -1,157 +0,0 @@
-// 1.2.840.10045.3.1.7
-// prime256v1 (ANSI X9.62 named elliptic curve)
-var OBJ_ID_EC  = '06 08 2A8648CE3D030107'.replace(/\s+/g, '').toLowerCase();
-// 1.3.132.0.34
-// secp384r1 (SECG (Certicom) named elliptic curve)
-var OBJ_ID_EC_384 = '06 05 2B81040022'.replace(/\s+/g, '').toLowerCase();
-
-var ECDSACSR = {};
-var ECDSA = {};
-var DER = {};
-var PEM = {};
-var ASN1;
-var Hex = {};
-var AB = {};
-
-//
-// CSR - the main event
-//
-
-ECDSACSR.create = function createEcCsr(keypem, domains) {
-  var pemblock = PEM.parseBlock(keypem);
-  var ecpub = PEM.parseEcPubkey(pemblock.der);
-  var request = ECDSACSR.request(ecpub, domains);
-  return AB.fromHex(ECDSACSR.sign(keypem, request));
-};
-
-ECDSACSR.request = function createCsrBodyEc(xy, domains) {
-  var publen = xy.x.byteLength;
-  var compression = '04';
-  var hxy = '';
-  // 04 == x+y, 02 == x-only
-  if (xy.y) {
-    publen += xy.y.byteLength;
-  } else {
-    // Note: I don't intend to support compression - it isn't used by most
-    // libraries and it requir more dependencies for bigint ops to deflate.
-    // This is more just a placeholder. It won't work right now anyway
-    // because compression requires an exta bit stored (odd vs even), which
-    // I haven't learned yet, and I'm not sure if it's allowed at all
-    compression = '02';
-  }
-  hxy += Hex.fromAB(xy.x);
-  if (xy.y) { hxy += Hex.fromAB(xy.y); }
-
-  // Sorry for the mess, but it is what it is
-  return ASN1('30'
-
-      // Version (0)
-    , ASN1.UInt('00')
-
-      // CN / Subject
-    , ASN1('30'
-      , ASN1('31'
-        , ASN1('30'
-            // object id (commonName)
-          , ASN1('06', '55 04 03')
-          , ASN1('0C', Hex.fromString(domains[0])))))
-
-      // EC P-256 Public Key
-    , ASN1('30'
-      , ASN1('30'
-          // 1.2.840.10045.2.1 ecPublicKey
-          // (ANSI X9.62 public key type)
-        , ASN1('06', '2A 86 48 CE 3D 02 01')
-          // 1.2.840.10045.3.1.7 prime256v1
-          // (ANSI X9.62 named elliptic curve)
-        , ASN1('06', '2A 86 48 CE 3D 03 01 07')
-        )
-      , ASN1.BitStr(compression + hxy))
-
-      // CSR Extension Subject Alternative Names
-    , ASN1('A0'
-      , ASN1('30'
-          // (extensionRequest (PKCS #9 via CRMF))
-        , ASN1('06', '2A 86 48 86 F7 0D 01 09 0E')
-        , ASN1('31'
-          , ASN1('30'
-            , ASN1('30'
-                // (subjectAltName (X.509 extension))
-              , ASN1('06', '55 1D 11')
-              , ASN1('04'
-                , ASN1('30', domains.map(function (d) {
-                    return ASN1('82', Hex.fromString(d));
-                  }).join(''))))))))
-  );
-};
-
-ECDSACSR.sign = function csrEcSig(keypem, request) {
-  var sig = ECDSA.sign(keypem, AB.fromHex(request));
-  var rLen = sig.r.byteLength;
-  var rc = '';
-  var sLen = sig.s.byteLength;
-  var sc = '';
-
-  if (0x80 & new Uint8Array(sig.r)[0]) { rc = '00'; rLen += 1; }
-  if (0x80 & new Uint8Array(sig.s)[0]) { sc = '00'; sLen += 1; }
-
-  return ASN1('30'
-      // The Full CSR Request Body
-    , request
-
-      // The Signature Type
-    , ASN1('30'
-        // 1.2.840.10045.4.3.2 ecdsaWithSHA256
-        // (ANSI X9.62 ECDSA algorithm with SHA256)
-      , ASN1('06', '2A 86 48 CE 3D 04 03 02')
-      )
-
-      // The Signature, embedded in a Bit Stream
-    , ASN1.BitStr(
-        // As far as I can tell this is a completely separate ASN.1 structure
-        // that just so happens to be embedded in a Bit String of another ASN.1
-        ASN1('30'
-        , ASN1.UInt(Hex.fromAB(sig.r))
-        , ASN1.UInt(Hex.fromAB(sig.s))))
-  );
-};
-
-//
-// ECDSA
-//
-
-// Took some tips from https://gist.github.com/codermapuche/da4f96cdb6d5ff53b7ebc156ec46a10a
-ECDSA.sign = function signEc(keypem, ab) {
-  // Signer is a stream
-  var sign = crypto.createSign('SHA256');
-  sign.write(new Uint8Array(ab));
-  sign.end();
-
-  // The signature is ASN1 encoded
-  var sig = sign.sign(keypem);
-
-  // Convert to a JavaScript ArrayBuffer just because
-  sig = new Uint8Array(sig.buffer.slice(sig.byteOffset, sig.byteOffset + sig.byteLength));
-
-  // The first two bytes '30 xx' signify SEQUENCE and LENGTH
-  // The sequence length byte will be a single byte because the signature is less that 128 bytes (0x80, 1024-bit)
-  // (this would not be true for P-521, but I'm not supporting that yet)
-  // The 3rd byte will be '02', signifying INTEGER
-  // The 4th byte will tell us the length of 'r' (which, on occassion, will be less than the full 255 bytes)
-  var rIndex = 3;
-  var rLen = sig[rIndex];
-  var rEnd = rIndex + 1 + rLen;
-  var sIndex = rEnd + 1;
-  var sLen = sig[sIndex];
-  var sEnd = sIndex + 1 + sLen;
-  var r = sig.slice(rIndex + 1, rEnd);
-  var s = sig.slice(sIndex + 1, sEnd); // this should be end-of-file
-
-  // ASN1 INTEGER types use the high-order bit to signify a negative number,
-  // hence a leading '00' is used for numbers that begin with '80' or greater
-  // which is why r length is sometimes a byte longer than its bit length
-  if (0 === s[0]) { s = s.slice(1); }
-  if (0 === r[0]) { r = r.slice(1); }
-
-  return { raw: sig.buffer, r: r.buffer, s: s.buffer };
-};

lib/csr.js

@@ -4,6 +4,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 (function (exports) {
 'use strict';
+/*global Promise*/
 
 var ASN1 = exports.ASN1;
 var Enc = exports.Enc;
@@ -15,17 +16,17 @@ var Keypairs = exports.Keypairs;
 var CSR = exports.CSR = function (opts) {
   // We're using a Promise here to be compatible with the browser version
   // which will probably use the webcrypto API for some of the conversions
-  opts = CSR._prepare(opts);
+  return CSR._prepare(opts).then(function (opts) {
-
     return CSR.create(opts).then(function (bytes) {
       return CSR._encode(opts, bytes);
     });
+  });
 };
 
 CSR._prepare = function (opts) {
-  var Rasha;
+  return Promise.resolve().then(function () {
+    var Keypairs;
     opts = JSON.parse(JSON.stringify(opts));
-  var pem, jwk;
 
     // We do a bit of extra error checking for user convenience
     if (!opts) { throw new Error("You must pass options with key and domains to rsacsr"); }
@@ -43,35 +44,29 @@ CSR._prepare = function (opts) {
       throw new Error("You must pass options.domains as strings");
     }
 
-  if (opts.pem) {
+    if (opts.jwk) { return opts; }
-    pem = opts.pem;
+    if (opts.key && opts.key.kty) {
-  } else if (opts.jwk) {
+      opts.jwk = opts.key;
-    jwk = opts.jwk;
+      return opts;
-  } else {
-    if (!opts.key) {
-      throw new Error("You must pass options.key as a JSON web key");
-    } else if (opts.key.kty) {
-      jwk = opts.key;
-    } else {
-      pem = opts.key;
     }
+    if (!opts.pem && !opts.key) {
+      throw new Error("You must pass options.key as a JSON web key");
     }
 
-  if (pem) {
+    Keypairs = exports.Keypairs;
-    try {
+    if (!exports.Keypairs) {
-      Rasha = require('rasha');
+      throw new Error("Keypairs.js is an optional dependency for PEM-to-JWK.\n"
-    } catch(e) {
-      throw new Error("Rasha.js is an optional dependency for PEM-to-JWK.\n"
         + "Install it if you'd like to use it:\n"
         + "\tnpm install --save rasha\n"
         + "Otherwise supply a jwk as the private key."
       );
     }
-    jwk = Rasha.importSync({ pem: pem });
-  }
 
-  opts.jwk = jwk;
+    return Keypairs.import({ pem: opts.pem || opts.key }).then(function (pair) {
+      opts.jwk = pair.private;
       return opts;
+    });
+  });
 };
 
 CSR._encode = function (opts, bytes) {
@@ -86,47 +81,56 @@ CSR._encode = function (opts, bytes) {
 
 CSR.create = function createCsr(opts) {
   var hex = CSR.request(opts.jwk, opts.domains);
-  return CSR.sign(opts.jwk, hex).then(function (csr) {
+  return CSR._sign(opts.jwk, hex).then(function (csr) {
     return Enc.hexToBuf(csr);
   });
 };
 
 //
-// RSA
+// EC / RSA
-//
 //
 CSR.request = function createCsrBodyEc(jwk, domains) {
-  var asn1pub = X509.packCsrRsaPublicKey(jwk);
+  var asn1pub;
-  return X509.packCsrRsa(asn1pub, domains);
+  if (/^EC/i.test(jwk.kty)) {
+    asn1pub = X509.packCsrEcPublicKey(jwk);
+  } else {
+    asn1pub = X509.packCsrRsaPublicKey(jwk);
+  }
+  return X509.packCsr(asn1pub, domains);
 };
 
-CSR.sign = function csrEcSig(jwk, request) {
+CSR._sign = function csrEcSig(jwk, request) {
   // Took some tips from https://gist.github.com/codermapuche/da4f96cdb6d5ff53b7ebc156ec46a10a
   // TODO will have to convert web ECDSA signatures to PEM ECDSA signatures (but RSA should be the same)
   // TODO have a consistent non-private way to sign
-  return Keypairs._sign({ jwk: jwk }, Enc.hexToBuf(request)).then(function (sig) {
+  return Keypairs._sign({ jwk: jwk, format: 'x509' }, Enc.hexToBuf(request)).then(function (sig) {
-    return CSR.toDer({ request: request, signature: sig });
+    return CSR._toDer({ request: request, signature: sig, kty: jwk.kty });
   });
 };
 
-
+CSR._toDer = function encode(opts) {
-CSR.toDer = function encode(opts) {
+  var sty;
-  var sty = ASN1('30'
+  var sig;
+  if (/^EC/i.test(opts.kty)) {
+    // 1.2.840.10045.4.3.2 ecdsaWithSHA256 (ANSI X9.62 ECDSA algorithm with SHA256)
+    sty = ASN1('30', ASN1('06', '2a8648ce3d040302'));
+    sig = ASN1.BitStr(ASN1('30', Enc.bufToHex(opts.signature)));
+  } else {
     // 1.2.840.113549.1.1.11 sha256WithRSAEncryption (PKCS #1)
-  , ASN1('06', '2a864886f70d01010b')
+    sty = ASN1('30', ASN1('06', '2a864886f70d01010b'), ASN1('05'));
-  , ASN1('05')
+    sig = ASN1.BitStr(Enc.bufToHex(opts.signature));
-  );
+  }
   return ASN1('30'
     // The Full CSR Request Body
   , opts.request
     // The Signature Type
   , sty
     // The Signature
-  , ASN1.BitStr(Enc.bufToHex(opts.signature))
+  , sig
   );
 };
 
-X509.packCsrRsa = function (asn1pubkey, domains) {
+X509.packCsr = function (asn1pubkey, domains) {
   return ASN1('30'
     // Version (0)
   , ASN1.UInt('00')
@@ -154,36 +158,42 @@ X509.packCsrRsa = function (asn1pubkey, domains) {
   );
 };
 
-X509.packPkcs1 = function (jwk) {
-  var n = ASN1.UInt(Enc.base64ToHex(jwk.n));
-  var e = ASN1.UInt(Enc.base64ToHex(jwk.e));
-
-  if (!jwk.d) {
-    return Enc.hexToBuf(ASN1('30', n, e));
-  }
-
-  return Enc.hexToBuf(ASN1('30'
-  , ASN1.UInt('00')
-  , n
-  , e
-  , ASN1.UInt(Enc.base64ToHex(jwk.d))
-  , ASN1.UInt(Enc.base64ToHex(jwk.p))
-  , ASN1.UInt(Enc.base64ToHex(jwk.q))
-  , ASN1.UInt(Enc.base64ToHex(jwk.dp))
-  , ASN1.UInt(Enc.base64ToHex(jwk.dq))
-  , ASN1.UInt(Enc.base64ToHex(jwk.qi))
-  ));
-};
-
 X509.packCsrRsaPublicKey = function (jwk) {
   // Sequence the key
   var n = ASN1.UInt(Enc.base64ToHex(jwk.n));
   var e = ASN1.UInt(Enc.base64ToHex(jwk.e));
   var asn1pub = ASN1('30', n, e);
-  //var asn1pub = X509.packPkcs1({ kty: jwk.kty, n: jwk.n, e: jwk.e });
 
   // Add the CSR pub key header
   return ASN1('30', ASN1('30', ASN1('06', '2a864886f70d010101'), ASN1('05')), ASN1.BitStr(asn1pub));
 };
 
+X509.packCsrEcPublicKey = function (jwk) {
+  var ecOid = X509._oids[jwk.crv];
+  if (!ecOid) {
+    throw new Error("Unsupported namedCurve '" + jwk.crv + "'. Supported types are " + Object.keys(X509._oids));
+  }
+  var cmp = '04'; // 04 == x+y, 02 == x-only
+  var hxy = '';
+  // Placeholder. I'm not even sure if compression should be supported.
+  if (!jwk.y) { cmp = '02'; }
+  hxy += Enc.base64ToHex(jwk.x);
+  if (jwk.y) { hxy += Enc.base64ToHex(jwk.y); }
+
+  // 1.2.840.10045.2.1 ecPublicKey
+  return ASN1('30', ASN1('30', ASN1('06', '2a8648ce3d0201'), ASN1('06', ecOid)), ASN1.BitStr(cmp + hxy));
+};
+X509._oids = {
+  // 1.2.840.10045.3.1.7 prime256v1
+  // (ANSI X9.62 named elliptic curve) (06 08 - 2A 86 48 CE 3D 03 01 07)
+  'P-256': '2a8648ce3d030107'
+  // 1.3.132.0.34 P-384 (06 05 - 2B 81 04 00 22)
+  // (SEC 2 recommended EC domain secp256r1)
+, 'P-384': '2b81040022'
+  // requires more logic and isn't a recommended standard
+  // 1.3.132.0.35 P-521 (06 05 - 2B 81 04 00 23)
+  // (SEC 2 alternate P-521)
+//, 'P-521': '2B 81 04 00 23'
+};
+
 }('undefined' === typeof window ? module.exports : window));

lib/keypairs.js

@@ -180,14 +180,6 @@ Keypairs.signJws = function (opts) {
       var msg = protected64 + '.' + payload64;
 
       return Keypairs._sign(opts, msg).then(function (buf) {
-        /*
-         * This will come back into play for CSRs, but not for JOSE
-        if ('EC' === opts.jwk.kty) {
-          // ECDSA JWT signatures differ from "normal" ECDSA signatures
-          // https://tools.ietf.org/html/rfc7518#section-3.4
-          binsig = convertIfEcdsa(binsig);
-        }
-        */
         var signedMsg = {
           protected: protected64
         , payload: payload64
@@ -212,40 +204,6 @@ Keypairs.signJws = function (opts) {
     }
   });
 };
-Keypairs._convertIfEcdsa = function (binsig) {
-  // should have asn1 sequence header of 0x30
-  if (0x30 !== binsig[0]) { throw new Error("Impossible EC SHA head marker"); }
-  var index = 2; // first ecdsa "R" header byte
-  var len = binsig[1];
-  var lenlen = 0;
-  // Seek length of length if length is greater than 127 (i.e. two 512-bit / 64-byte R and S values)
-  if (0x80 & len) {
-    lenlen = len - 0x80; // should be exactly 1
-    len = binsig[2]; // should be <= 130 (two 64-bit SHA-512s, plus padding)
-    index += lenlen;
-  }
-  // should be of BigInt type
-  if (0x02 !== binsig[index]) { throw new Error("Impossible EC SHA R marker"); }
-  index += 1;
-
-  var rlen = binsig[index];
-  var bits = 32;
-  if (rlen > 49) {
-    bits = 64;
-  } else if (rlen > 33) {
-    bits = 48;
-  }
-  var r = binsig.slice(index + 1, index + 1 + rlen).toString('hex');
-  var slen = binsig[index + 1 + rlen + 1]; // skip header and read length
-  var s = binsig.slice(index + 1 + rlen + 1 + 1).toString('hex');
-  if (2 *slen !== s.length) { throw new Error("Impossible EC SHA S length"); }
-  // There may be one byte of padding on either
-  while (r.length < 2*bits) { r = '00' + r; }
-  while (s.length < 2*bits) { s = '00' + s; }
-  if (2*(bits+1) === r.length) { r = r.slice(2); }
-  if (2*(bits+1) === s.length) { s = s.slice(2); }
-  return Enc.hexToBuf(r + s);
-};
 
 Keypairs._sign = function (opts, payload) {
   return Keypairs._import(opts).then(function (privkey) {
@@ -259,9 +217,12 @@ Keypairs._sign = function (opts, payload) {
     , privkey
     , payload
     ).then(function (signature) {
-      // convert buffer to urlsafe base64
+      signature = new Uint8Array(signature); // ArrayBuffer -> u8
-      //return Enc.bufToUrlBase64(new Uint8Array(signature));
+      // This will come back into play for CSRs, but not for JOSE
-      return new Uint8Array(signature);
+      if ('EC' === opts.jwk.kty && /x509/i.test(opts.format)) {
+        signature = Keypairs._ecdsaJoseSigToAsn1Sig(signature);
+      }
+      return signature;
     });
   });
 };
@@ -287,7 +248,6 @@ Keypairs._getName = function (opts) {
     return 'RSASSA-PKCS1-v1_5';
   }
 };
-
 Keypairs._import = function (opts) {
   return Promise.resolve().then(function () {
     var ops;
@@ -316,6 +276,30 @@ Keypairs._import = function (opts) {
     });
   });
 };
+// ECDSA JOSE / JWS / JWT signatures differ from "normal" ASN1/X509 ECDSA signatures
+// https://tools.ietf.org/html/rfc7518#section-3.4
+Keypairs._ecdsaJoseSigToAsn1Sig = function (bufsig) {
+  // it's easier to do the manipulation in the browser with an array
+  bufsig = Array.from(bufsig);
+  var hlen = bufsig.length / 2; // should be even
+  var r = bufsig.slice(0, hlen);
+  var s = bufsig.slice(hlen);
+  // unpad positive ints less than 32 bytes wide
+  while (!r[0]) { r = r.slice(1); }
+  while (!s[0]) { s = s.slice(1); }
+  // pad (or re-pad) ambiguously non-negative BigInts, up to 33 bytes wide
+  if (0x80 & r[0]) { r.unshift(0); }
+  if (0x80 & s[0]) { s.unshift(0); }
+
+  var len = 2 + r.length + 2 + s.length;
+  var head = [0x30];
+  // hard code 0x80 + 1 because it won't be longer than
+  // two SHA512 plus two pad bytes (130 bytes <= 256)
+  if (len >= 0x80) { head.push(0x81); }
+  head.push(len);
+
+  return Uint8Array.from(head.concat([0x02, r.length], r, [0x02, s.byteLength], s));
+};
 
 function setTime(time) {
   if ('number' === typeof time) { return time; }

lib/x509.js

@@ -1,6 +1,6 @@
-'use strict';
 (function (exports) {
   'use strict';
+
   var x509 = exports.x509 = {};
   var ASN1 = exports.ASN1;
   var Enc = exports.Enc;