sdfsdfs

node_modules/browserify-sign/browser/verify.js

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+'use strict';
+
+// much of this based on https://github.com/indutny/self-signed/blob/gh-pages/lib/rsa.js
+var Buffer = require('safe-buffer').Buffer;
+var BN = require('bn.js');
+var EC = require('elliptic').ec;
+var parseKeys = require('parse-asn1');
+var curves = require('./curves.json');
+
+function verify(sig, hash, key, signType, tag) {
+  var pub = parseKeys(key);
+  if (pub.type === 'ec') {
+    // rsa keys can be interpreted as ecdsa ones in openssl
+    if (signType !== 'ecdsa' && signType !== 'ecdsa/rsa') { throw new Error('wrong public key type'); }
+    return ecVerify(sig, hash, pub);
+  } else if (pub.type === 'dsa') {
+    if (signType !== 'dsa') { throw new Error('wrong public key type'); }
+    return dsaVerify(sig, hash, pub);
+  }
+  if (signType !== 'rsa' && signType !== 'ecdsa/rsa') { throw new Error('wrong public key type'); }
+
+  hash = Buffer.concat([tag, hash]);
+  var len = pub.modulus.byteLength();
+  var pad = [1];
+  var padNum = 0;
+  while (hash.length + pad.length + 2 < len) {
+    pad.push(0xff);
+    padNum += 1;
+  }
+  pad.push(0x00);
+  var i = -1;
+  while (++i < hash.length) {
+    pad.push(hash[i]);
+  }
+  pad = Buffer.from(pad);
+  var red = BN.mont(pub.modulus);
+  sig = new BN(sig).toRed(red);
+
+  sig = sig.redPow(new BN(pub.publicExponent));
+  sig = Buffer.from(sig.fromRed().toArray());
+  var out = padNum < 8 ? 1 : 0;
+  len = Math.min(sig.length, pad.length);
+  if (sig.length !== pad.length) { out = 1; }
+
+  i = -1;
+  while (++i < len) { out |= sig[i] ^ pad[i]; }
+  return out === 0;
+}
+
+function ecVerify(sig, hash, pub) {
+  var curveId = curves[pub.data.algorithm.curve.join('.')];
+  if (!curveId) { throw new Error('unknown curve ' + pub.data.algorithm.curve.join('.')); }
+
+  var curve = new EC(curveId);
+  var pubkey = pub.data.subjectPrivateKey.data;
+
+  return curve.verify(hash, sig, pubkey);
+}
+
+function dsaVerify(sig, hash, pub) {
+  var p = pub.data.p;
+  var q = pub.data.q;
+  var g = pub.data.g;
+  var y = pub.data.pub_key;
+  var unpacked = parseKeys.signature.decode(sig, 'der');
+  var s = unpacked.s;
+  var r = unpacked.r;
+  checkValue(s, q);
+  checkValue(r, q);
+  var montp = BN.mont(p);
+  var w = s.invm(q);
+  var v = g.toRed(montp)
+    .redPow(new BN(hash).mul(w).mod(q))
+    .fromRed()
+    .mul(y.toRed(montp).redPow(r.mul(w).mod(q)).fromRed())
+    .mod(p)
+    .mod(q);
+  return v.cmp(r) === 0;
+}
+
+function checkValue(b, q) {
+  if (b.cmpn(0) <= 0) { throw new Error('invalid sig'); }
+  if (b.cmp(q) >= 0) { throw new Error('invalid sig'); }
+}
+
+module.exports = verify;