initial commit for GitHub

core/codecBase64.js

@@ -0,0 +1,56 @@
+/** @fileOverview Bit array codec implementations.
+ *
+ * @author Emily Stark
+ * @author Mike Hamburg
+ * @author Dan Boneh
+ */
+
+/** @namespace Base64 encoding/decoding */
+sjcl.codec.base64 = {
+  /** The base64 alphabet.
+   * @private
+   */
+  _chars: "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/",
+  
+  /** Convert from a bitArray to a base64 string. */
+  fromBits: function (arr, _noEquals) {
+    var out = "", i, bits=0, c = sjcl.codec.base64._chars, ta=0, bl = sjcl.bitArray.bitLength(arr);
+    for (i=0; out.length * 6 < bl; ) {
+      out += c.charAt((ta ^ arr[i]>>>bits) >>> 26);
+      if (bits < 6) {
+        ta = arr[i] << (6-bits);
+        bits += 26;
+        i++;
+      } else {
+        ta <<= 6;
+        bits -= 6;
+      }
+    }
+    while ((out.length & 3) && !_noEquals) { out += "="; }
+    return out;
+  },
+  
+  /** Convert from a base64 string to a bitArray */
+  toBits: function(str) {
+    str = str.replace(/\s|=/g,'');
+    var out = [], i, bits=0, c = sjcl.codec.base64._chars, ta=0, x;
+    for (i=0; i<str.length; i++) {
+      x = c.indexOf(str.charAt(i));
+      if (x < 0) {
+        throw new sjcl.exception.invalid("this isn't base64!");
+      }
+      if (bits > 26) {
+        bits -= 26;
+        out.push(ta ^ x>>>bits);
+        ta  = x << (32-bits);
+      } else {
+        bits += 6;
+        ta ^= x << (32-bits);
+      }
+    }
+    if (bits&56) {
+      out.push(sjcl.bitArray.partial(bits&56, ta, 1));
+    }
+    return out;
+  }
+};