From b1fcfeaa31a620d507f77369267fd420c2c6bbe9 Mon Sep 17 00:00:00 2001
From: Saurav Sachidanand <sauravsachidanand@gmail.com>
Date: Sat, 19 May 2018 18:17:29 +0530
Subject: [PATCH] Add verifying raw signature

---
 src/rsasign-1.2.js | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/src/rsasign-1.2.js b/src/rsasign-1.2.js
index 4fb2b0cb..4f0b9d08 100644
--- a/src/rsasign-1.2.js
+++ b/src/rsasign-1.2.js
@@ -221,6 +221,26 @@ function _rsasign_getAlgNameAndHashFromHexDisgestInfo(hDigestInfo) {
     return [];
 }
 
+/**
+ * verifies a raw RSA sigature for a message string with RSA public key.<br/>
+ * @name verifyRawWithMessageHex
+ * @memberOf RSAKey#
+ * @function
+ * @param {String} sMsgHex hexadecimal string of message to be verified.
+ * @param {String} hSig hexadecimal string of raw siganture.<br/>
+ *                 non-hexadecimal charactors including new lines will be ignored.
+ * @return returns 1 if valid, otherwise 0
+ */
+RSAKey.prototype.verifyRawWithMessageHex = function(sMsgHex, hSig) {
+    hSig = hSig.replace(_RE_HEXDECONLY, '');
+    hSig = hSig.replace(/[ \n]+/g, "");
+    var biSig = parseBigInt(hSig, 16);
+    if (biSig.bitLength() > this.n.bitLength()) return 0;
+    var biDecryptedSig = this.doPublic(biSig);
+    var hMsgHex = biDecryptedSig.toString(16).replace(/^1f+00/, '');
+    return (hMsgHex == sMsgHex);
+};
+
 /**
  * verifies a sigature for a message string with RSA public key.<br/>
  * @name verify