initial commit for GitHub

test/sha256_test_brute_force.js

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+/**
+ * Test SHA-256 using an ad-hoc iterative technique.
+ * This uses a string buffer which has n characters on the nth iteration.
+ * Each iteration, the buffer is hashed and the hash is converted to a string.
+ * The first two characters of the string are prepended to the buffer, then the
+ * last character of the buffer is removed.  This way, neither the beginning nor
+ * the end of the buffer is fixed.
+ *
+ * The hashes from each output step are also hashed together into one final hash.
+ * This is compared against a final hash which was computed with SSL.
+ */
+
+new sjcl.test.TestCase("SHA-256 iterative", function (cb) {
+  if (!sjcl.hash.sha256) {
+    this.unimplemented();
+    cb && cb();
+    return;
+  }
+  
+  var toBeHashed = "", cumulative = new sjcl.hash.sha256(), hash, thiz=this;
+  browserUtil.cpsIterate(function (i, cbb) {
+    for (var n=100*i; n<100*(i+1); n++) {
+      hash = sjcl.hash.sha256.hash(toBeHashed);
+      hash = sjcl.codec.hex.fromBits(hash);
+      cumulative.update(hash);
+      toBeHashed = (hash.substring(0,2)+toBeHashed).substring(0,n+1);
+    }
+    cbb && cbb();
+  }, 0, 10, true, function () {
+    hash = sjcl.codec.hex.fromBits(cumulative.finalize());
+    thiz.require(hash === "f305c76d5d457ddf04f1927166f5e13429407049a5c5f29021916321fcdcd8b4");
+    cb && cb();
+  });
+});