Merge pull request #167 from zkemail/upstream-nozee

Upstreaming ASCII from nozee

packages/circuits/helpers/ascii.circom

@@ -0,0 +1,19 @@
+pragma circom 2.1.4;
+include "circomlib/circuits/comparators.circom";
+
+// from nozee (emmaguo13, sehyunc, kaylee)
+// https://github.com/emmaguo13/zk-blind/blob/master/circuits/ascii.circom
+// only converts ascii to numbers from 0-9
+template AsciiToNum (max_input) {
+    signal input in[max_input];
+    signal output out;
+
+    var temp = in[0] - 48;
+
+    for (var i = 1; i < max_input; i++) {
+        temp *= 10;
+        temp += in[i] - 48;
+    }
+
+    out <== temp;
+}

packages/circuits/helpers/rsa.circom

@@ -47,6 +47,8 @@ template RSAPad(n, k) {
     signal input base_message[k];
     signal output padded_message[k];
 
+    // The extra 152 bits comes from 0x3031300d060960864801650304020105000420
+    // This is due to padding from the RSASSA-PKCS1-v1_5 standard
     var base_len = 408;
     var msg_len = 256;