First iteration sha256

test/circuits/sha256_2_test.circom

@@ -0,0 +1,15 @@
+include "../../circuits/sha256/sha256_2.circom";
+
+template Main() {
+    signal private input a;
+    signal private input b;
+    signal output out;
+
+    component sha256_2 = Sha256_2();
+
+    sha256_2.a <== a;
+    sha256_2.b <== a;
+    out <== sha256_2.out;
+}
+
+component main = Main();

test/sha256.js

@@ -1,6 +1,7 @@
 const chai = require("chai");
 const path = require("path");
 const zkSnark = require("zksnark");
+const crypto = require("crypto");
 
 const compiler = require("../index.js");
 
@@ -31,6 +32,23 @@ describe("SHA256 test", () => {
         assert(witness[0].equals(zkSnark.bigInt(1)));
         assert(witness[1].equals(zkSnark.bigInt("333")));
     });
+    it("Should calculate a hash", async () => {
+        const cirDef = await compiler(path.join(__dirname, "circuits", "sha256_2_test.circom"));
+        const circuit = new zkSnark.Circuit(cirDef);
+
+        const witness = circuit.calculateWitness({ "a": "1", "b": "2" });
+
+        const b = new Buffer.alloc(432);
+        b[115] = 1;
+        b[431] = 2;
+
+        const hash = crypto.createHash("sha256")
+            .update(b)
+            .digest("hex");
+        const r = "0x" + hash.slice(40);
+
+        assert(witness[1].equals(zkSnark.bigInt(r)));
+    });
 
 
 });