1 files changed, 112 insertions, 0 deletions
diff --git a/webclient/lib/rsa.js b/webclient/lib/rsa.js
new file mode 100644
index 0000000..9f86640
--- /dev/null
+++ b/webclient/lib/rsa.js
@@ -0,0 +1,112 @@
+// Depends on jsbn.js and rng.js
+
+// Version 1.1: support utf-8 encoding in pkcs1pad2
+
+// convert a (hex) string to a bignum object
+function parseBigInt(str,r) {
+  return new BigInteger(str,r);
+}
+
+function linebrk(s,n) {
+  var ret = "";
+  var i = 0;
+  while(i + n < s.length) {
+    ret += s.substring(i,i+n) + "\n";
+    i += n;
+  }
+  return ret + s.substring(i,s.length);
+}
+
+function byte2Hex(b) {
+  if(b < 0x10)
+    return "0" + b.toString(16);
+  else
+    return b.toString(16);
+}
+
+// PKCS#1 (type 2, random) pad input string s to n bytes, and return a bigint
+function pkcs1pad2(s,n) {
+  if(n < s.length + 11) { // TODO: fix for utf-8
+    alert("Message too long for RSA");
+    return null;
+  }
+  var ba = new Array();
+  var i = s.length - 1;
+  while(i >= 0 && n > 0) {
+    var c = s.charCodeAt(i--);
+    if(c < 128) { // encode using utf-8
+      ba[--n] = c;
+    }
+    else if((c > 127) && (c < 2048)) {
+      ba[--n] = (c & 63) | 128;
+      ba[--n] = (c >> 6) | 192;
+    }
+    else {
+      ba[--n] = (c & 63) | 128;
+      ba[--n] = ((c >> 6) & 63) | 128;
+      ba[--n] = (c >> 12) | 224;
+    }
+  }
+  ba[--n] = 0;
+  var rng = new SecureRandom();
+  var x = new Array();
+  while(n > 2) { // random non-zero pad
+    x[0] = 0;
+    while(x[0] == 0) rng.nextBytes(x);
+    ba[--n] = x[0];
+  }
+  ba[--n] = 2;
+  ba[--n] = 0;
+  return new BigInteger(ba);
+}
+
+// "empty" RSA key constructor
+function RSAKey() {
+  this.n = null;
+  this.e = 0;
+  this.d = null;
+  this.p = null;
+  this.q = null;
+  this.dmp1 = null;
+  this.dmq1 = null;
+  this.coeff = null;
+}
+
+// Set the public key fields N and e from hex strings
+function RSASetPublic(N,E) {
+  if(N != null && E != null && N.length > 0 && E.length > 0) {
+    this.n = parseBigInt(N,16);
+    this.e = parseInt(E,16);
+  }
+  else
+    alert("Invalid RSA public key");
+}
+
+// Perform raw public operation on "x": return x^e (mod n)
+function RSADoPublic(x) {
+  return x.modPowInt(this.e, this.n);
+}
+
+// Return the PKCS#1 RSA encryption of "text" as an even-length hex string
+function RSAEncrypt(text) {
+  var m = pkcs1pad2(text,(this.n.bitLength()+7)>>3);
+  if(m == null) return null;
+  var c = this.doPublic(m);
+  if(c == null) return null;
+  var h = c.toString(16);
+  if((h.length & 1) == 0) return h; else return "0" + h;
+}
+
+// Return the PKCS#1 RSA encryption of "text" as a Base64-encoded string
+//function RSAEncryptB64(text) {
+//  var h = this.encrypt(text);
+//  if(h) return hex2b64(h); else return null;
+//}
+
+// protected
+RSAKey.prototype.doPublic = RSADoPublic;
+
+// public
+RSAKey.prototype.setPublic = RSASetPublic;
+RSAKey.prototype.encrypt = RSAEncrypt;
+//RSAKey.prototype.encrypt_b64 = RSAEncryptB64;