blockbufs2buf

lib/expmt/cbc.js

@@ -27,6 +27,18 @@ CBC.buf2blockbufs = function(buf, blocksize) {
   return blockbufs;
 };
 
+CBC.blockbufs2buf = function(blockbufs, blocksize) {
+  var bytesize = blocksize / 8;
+
+  var last = blockbufs[blockbufs.length - 1];
+  last = CBC.pkcs7unpad(last);
+  blockbufs[blockbufs.length - 1] = last;
+
+  var buf = Buffer.concat(blockbufs);
+
+  return buf;
+};
+
 CBC.encrypt = function(messagebuf, ivbuf, blockcipher, cipherkeybuf) {
   var blocksize = ivbuf.length * 8;
   var blockbufs = CBC.buf2blockbufs(messagebuf, blocksize);

test/test.cbc.js

@@ -34,6 +34,26 @@ describe('CBC', function() {
 
   });
   
+  describe('@buf2blockbufs', function() {
+
+    it('should convert this buffer into one block and back into the same buffer', function() {
+      var buf = new Buffer(16 - 1);
+      buf.fill(0);
+      var blockbufs = CBC.buf2blockbufs(buf, 16 * 8);
+      var buf2 = CBC.blockbufs2buf(blockbufs, 16 * 8);
+      buf2.toString('hex').should.equal(buf.toString('hex'));
+    });
+
+    it('should convert this buffer into two blocks and back into the same buffer', function() {
+      var buf = new Buffer(16);
+      buf.fill(0);
+      var blockbufs = CBC.buf2blockbufs(buf, 16 * 8);
+      var buf2 = CBC.blockbufs2buf(blockbufs, 16 * 8);
+      buf2.toString('hex').should.equal(buf.toString('hex'));
+    });
+
+  });
+  
   describe('@encrypt', function() {
 
     it('should return this known value', function() {