1 files changed, 84 insertions, 0 deletions
diff --git a/node_modules/browserify-sign/browser/verify.js b/node_modules/browserify-sign/browser/verify.js
new file mode 100644
index 0000000..907bce6
--- /dev/null
+++ b/node_modules/browserify-sign/browser/verify.js
@@ -0,0 +1,84 @@
+// 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)
+  } else {
+    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++
+  }
+  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) >= q) throw new Error('invalid sig')
+}
+
+module.exports = verify