1 files changed, 60 insertions, 28 deletions

diff --git a/core/ccm.js b/core/ccm.js
index 8a32c5a..1efde02 100644
--- a/core/ccm.js
+++ b/core/ccm.js
@@ -15,6 +15,27 @@ sjcl.mode.ccm = {
    */
   name: "ccm",
   
+  _progressListeners: [],
+
+  listenProgress: function (cb) {
+    sjcl.mode.ccm._progressListeners.push(cb);
+  },
+
+  unListenProgress: function (cb) {
+    var index = sjcl.mode.ccm._progressListeners.indexOf(cb);
+    if (index > -1) {
+      sjcl.mode.ccm._progressListeners.splice(index, 1);
+    }
+  },
+
+  _callProgressListener: function (val) {
+    var p = sjcl.mode.ccm._progressListeners.slice(), i;
+
+    for (i = 0; i < p.length; i += 1) {
+      p[i](val);
+    }
+  },
+
   /** Encrypt in CCM mode.
    * @static
    * @param {Object} prf The pseudorandom function.  It must have a block size of 16 bytes.
@@ -25,7 +46,7 @@ sjcl.mode.ccm = {
    * @return {bitArray} The encrypted data, an array of bytes.
    */
   encrypt: function(prf, plaintext, iv, adata, tlen) {
-    var L, i, out = plaintext.slice(0), tag, w=sjcl.bitArray, ivl = w.bitLength(iv) / 8, ol = w.bitLength(out) / 8;
+    var L, out = plaintext.slice(0), tag, w=sjcl.bitArray, ivl = w.bitLength(iv) / 8, ol = w.bitLength(out) / 8;
     tlen = tlen || 64;
     adata = adata || [];
     
@@ -59,7 +80,7 @@ sjcl.mode.ccm = {
   decrypt: function(prf, ciphertext, iv, adata, tlen) {
     tlen = tlen || 64;
     adata = adata || [];
-    var L, i, 
+    var L,
         w=sjcl.bitArray,
         ivl = w.bitLength(iv) / 8,
         ol = w.bitLength(ciphertext), 
@@ -90,6 +111,36 @@ sjcl.mode.ccm = {
     return out.data;
   },
 
+  _macAdditionalData: function (prf, adata, iv, tlen, ol, L) {
+    var mac, tmp, i, macData = [], w=sjcl.bitArray, xor = w._xor4;
+
+    // mac the flags
+    mac = [w.partial(8, (adata.length ? 1<<6 : 0) | (tlen-2) << 2 | L-1)];
+
+    // mac the iv and length
+    mac = w.concat(mac, iv);
+    mac[3] |= ol;
+    mac = prf.encrypt(mac);
+  
+    if (adata.length) {
+      // mac the associated data.  start with its length...
+      tmp = w.bitLength(adata)/8;
+      if (tmp <= 0xFEFF) {
+        macData = [w.partial(16, tmp)];
+      } else if (tmp <= 0xFFFFFFFF) {
+        macData = w.concat([w.partial(16,0xFFFE)], [tmp]);
+      } // else ...
+    
+      // mac the data itself
+      macData = w.concat(macData, adata);
+      for (i=0; i<macData.length; i += 4) {
+        mac = prf.encrypt(xor(mac, macData.slice(i,i+4).concat([0,0,0])));
+      }
+    }
+
+    return mac;
+  },
+
   /* Compute the (unencrypted) authentication tag, according to the CCM specification
    * @param {Object} prf The pseudorandom function.
    * @param {bitArray} plaintext The plaintext data.
@@ -101,7 +152,7 @@ sjcl.mode.ccm = {
    */
   _computeTag: function(prf, plaintext, iv, adata, tlen, L) {
     // compute B[0]
-    var q, mac, field = 0, offset = 24, tmp, i, macData = [], w=sjcl.bitArray, xor = w._xor4;
+    var mac, i, w=sjcl.bitArray, xor = w._xor4;
 
     tlen /= 8;
   
@@ -115,31 +166,8 @@ sjcl.mode.ccm = {
       throw new sjcl.exception.bug("ccm: can't deal with 4GiB or more data");
     }
 
-    // mac the flags
-    mac = [w.partial(8, (adata.length ? 1<<6 : 0) | (tlen-2) << 2 | L-1)];
+    mac = sjcl.mode.ccm._macAdditionalData(prf, adata, iv, tlen, w.bitLength(plaintext)/8, L);
 
-    // mac the iv and length
-    mac = w.concat(mac, iv);
-    mac[3] |= w.bitLength(plaintext)/8;
-    mac = prf.encrypt(mac);
-    
-  
-    if (adata.length) {
-      // mac the associated data.  start with its length...
-      tmp = w.bitLength(adata)/8;
-      if (tmp <= 0xFEFF) {
-        macData = [w.partial(16, tmp)];
-      } else if (tmp <= 0xFFFFFFFF) {
-        macData = w.concat([w.partial(16,0xFFFE)], [tmp]);
-      } // else ...
-    
-      // mac the data itself
-      macData = w.concat(macData, adata);
-      for (i=0; i<macData.length; i += 4) {
-        mac = prf.encrypt(xor(mac, macData.slice(i,i+4).concat([0,0,0])));
-      }
-    }
-  
     // mac the plaintext
     for (i=0; i<plaintext.length; i+=4) {
       mac = prf.encrypt(xor(mac, plaintext.slice(i,i+4).concat([0,0,0])));
@@ -161,7 +189,7 @@ sjcl.mode.ccm = {
    * @private
    */
   _ctrMode: function(prf, data, iv, tag, tlen, L) {
-    var enc, i, w=sjcl.bitArray, xor = w._xor4, ctr, b, l = data.length, bl=w.bitLength(data);
+    var enc, i, w=sjcl.bitArray, xor = w._xor4, ctr, l = data.length, bl=w.bitLength(data), n = l/50, p = n;
 
     // start the ctr
     ctr = w.concat([w.partial(8,L-1)],iv).concat([0,0,0]).slice(0,4);
@@ -173,6 +201,10 @@ sjcl.mode.ccm = {
     if (!l) { return {tag:tag, data:[]}; }
     
     for (i=0; i<l; i+=4) {
+      if (i > n) {
+        sjcl.mode.ccm._callProgressListener(i/l);
+        n += p;
+      }
       ctr[3]++;
       enc = prf.encrypt(ctr);
       data[i]   ^= enc[0];