From 30000ad7c0b96d5e8bf6dc554a568f95c9aee18c Mon Sep 17 00:00:00 2001
From: Dmitry Chestnykh <dmitry@codingrobots.com>
Date: Mon, 28 Mar 2016 19:36:12 +0200
Subject: [PATCH] Switch Poly1305 fast version back to original

There is a bug in fast version, which was ported from
16-bit Poly1305-donna, where the bug comes from:
https://github.com/floodyberry/poly1305-donna/issues/2

Until we figure out the source of bug, return nacl-fast version to match
the original nacl version.
---
 nacl-fast.js | 413 ++++++++-------------------------------------------
 1 file changed, 58 insertions(+), 355 deletions(-)

diff --git a/nacl-fast.js b/nacl-fast.js
index e9a121fa..4f83b5c7 100644
--- a/nacl-fast.js
+++ b/nacl-fast.js
@@ -459,367 +459,70 @@ function crypto_stream_xor(c,cpos,m,mpos,d,n,k) {
   return crypto_stream_salsa20_xor(c,cpos,m,mpos,d,sn,s);
 }
 
-/*
-* Port of Andrew Moon's Poly1305-donna-16. Public domain.
-* https://github.com/floodyberry/poly1305-donna
-*/
-
-var poly1305 = function(key) {
-  this.buffer = new Uint8Array(16);
-  this.r = new Uint16Array(10);
-  this.h = new Uint16Array(10);
-  this.pad = new Uint16Array(8);
-  this.leftover = 0;
-  this.fin = 0;
-
-  var t0, t1, t2, t3, t4, t5, t6, t7;
-
-  t0 = key[ 0] & 0xff | (key[ 1] & 0xff) << 8; this.r[0] = ( t0                     ) & 0x1fff;
-  t1 = key[ 2] & 0xff | (key[ 3] & 0xff) << 8; this.r[1] = ((t0 >>> 13) | (t1 <<  3)) & 0x1fff;
-  t2 = key[ 4] & 0xff | (key[ 5] & 0xff) << 8; this.r[2] = ((t1 >>> 10) | (t2 <<  6)) & 0x1f03;
-  t3 = key[ 6] & 0xff | (key[ 7] & 0xff) << 8; this.r[3] = ((t2 >>>  7) | (t3 <<  9)) & 0x1fff;
-  t4 = key[ 8] & 0xff | (key[ 9] & 0xff) << 8; this.r[4] = ((t3 >>>  4) | (t4 << 12)) & 0x00ff;
-  this.r[5] = ((t4 >>>  1)) & 0x1ffe;
-  t5 = key[10] & 0xff | (key[11] & 0xff) << 8; this.r[6] = ((t4 >>> 14) | (t5 <<  2)) & 0x1fff;
-  t6 = key[12] & 0xff | (key[13] & 0xff) << 8; this.r[7] = ((t5 >>> 11) | (t6 <<  5)) & 0x1f81;
-  t7 = key[14] & 0xff | (key[15] & 0xff) << 8; this.r[8] = ((t6 >>>  8) | (t7 <<  8)) & 0x1fff;
-  this.r[9] = ((t7 >>>  5)) & 0x007f;
-
-  this.pad[0] = key[16] & 0xff | (key[17] & 0xff) << 8;
-  this.pad[1] = key[18] & 0xff | (key[19] & 0xff) << 8;
-  this.pad[2] = key[20] & 0xff | (key[21] & 0xff) << 8;
-  this.pad[3] = key[22] & 0xff | (key[23] & 0xff) << 8;
-  this.pad[4] = key[24] & 0xff | (key[25] & 0xff) << 8;
-  this.pad[5] = key[26] & 0xff | (key[27] & 0xff) << 8;
-  this.pad[6] = key[28] & 0xff | (key[29] & 0xff) << 8;
-  this.pad[7] = key[30] & 0xff | (key[31] & 0xff) << 8;
-};
-
-poly1305.prototype.blocks = function(m, mpos, bytes) {
-  var hibit = this.fin ? 0 : (1 << 11);
-  var t0, t1, t2, t3, t4, t5, t6, t7, c;
-  var d0, d1, d2, d3, d4, d5, d6, d7, d8, d9;
-
-  var h0 = this.h[0],
-      h1 = this.h[1],
-      h2 = this.h[2],
-      h3 = this.h[3],
-      h4 = this.h[4],
-      h5 = this.h[5],
-      h6 = this.h[6],
-      h7 = this.h[7],
-      h8 = this.h[8],
-      h9 = this.h[9];
-
-  var r0 = this.r[0],
-      r1 = this.r[1],
-      r2 = this.r[2],
-      r3 = this.r[3],
-      r4 = this.r[4],
-      r5 = this.r[5],
-      r6 = this.r[6],
-      r7 = this.r[7],
-      r8 = this.r[8],
-      r9 = this.r[9];
-
-  while (bytes >= 16) {
-    t0 = m[mpos+ 0] & 0xff | (m[mpos+ 1] & 0xff) << 8; h0 += ( t0                     ) & 0x1fff;
-    t1 = m[mpos+ 2] & 0xff | (m[mpos+ 3] & 0xff) << 8; h1 += ((t0 >>> 13) | (t1 <<  3)) & 0x1fff;
-    t2 = m[mpos+ 4] & 0xff | (m[mpos+ 5] & 0xff) << 8; h2 += ((t1 >>> 10) | (t2 <<  6)) & 0x1fff;
-    t3 = m[mpos+ 6] & 0xff | (m[mpos+ 7] & 0xff) << 8; h3 += ((t2 >>>  7) | (t3 <<  9)) & 0x1fff;
-    t4 = m[mpos+ 8] & 0xff | (m[mpos+ 9] & 0xff) << 8; h4 += ((t3 >>>  4) | (t4 << 12)) & 0x1fff;
-    h5 += ((t4 >>>  1)) & 0x1fff;
-    t5 = m[mpos+10] & 0xff | (m[mpos+11] & 0xff) << 8; h6 += ((t4 >>> 14) | (t5 <<  2)) & 0x1fff;
-    t6 = m[mpos+12] & 0xff | (m[mpos+13] & 0xff) << 8; h7 += ((t5 >>> 11) | (t6 <<  5)) & 0x1fff;
-    t7 = m[mpos+14] & 0xff | (m[mpos+15] & 0xff) << 8; h8 += ((t6 >>>  8) | (t7 <<  8)) & 0x1fff;
-    h9 += ((t7 >>> 5)) | hibit;
-
-    c = 0;
-
-    d0 = c;
-    d0 += h0 * r0;
-    d0 += h1 * (5 * r9);
-    d0 += h2 * (5 * r8);
-    d0 += h3 * (5 * r7);
-    d0 += h4 * (5 * r6);
-    c = (d0 >>> 13); d0 &= 0x1fff;
-    d0 += h5 * (5 * r5);
-    d0 += h6 * (5 * r4);
-    d0 += h7 * (5 * r3);
-    d0 += h8 * (5 * r2);
-    d0 += h9 * (5 * r1);
-    c += (d0 >>> 13); d0 &= 0x1fff;
-
-    d1 = c;
-    d1 += h0 * r1;
-    d1 += h1 * r0;
-    d1 += h2 * (5 * r9);
-    d1 += h3 * (5 * r8);
-    d1 += h4 * (5 * r7);
-    c = (d1 >>> 13); d1 &= 0x1fff;
-    d1 += h5 * (5 * r6);
-    d1 += h6 * (5 * r5);
-    d1 += h7 * (5 * r4);
-    d1 += h8 * (5 * r3);
-    d1 += h9 * (5 * r2);
-    c += (d1 >>> 13); d1 &= 0x1fff;
-
-    d2 = c;
-    d2 += h0 * r2;
-    d2 += h1 * r1;
-    d2 += h2 * r0;
-    d2 += h3 * (5 * r9);
-    d2 += h4 * (5 * r8);
-    c = (d2 >>> 13); d2 &= 0x1fff;
-    d2 += h5 * (5 * r7);
-    d2 += h6 * (5 * r6);
-    d2 += h7 * (5 * r5);
-    d2 += h8 * (5 * r4);
-    d2 += h9 * (5 * r3);
-    c += (d2 >>> 13); d2 &= 0x1fff;
-
-    d3 = c;
-    d3 += h0 * r3;
-    d3 += h1 * r2;
-    d3 += h2 * r1;
-    d3 += h3 * r0;
-    d3 += h4 * (5 * r9);
-    c = (d3 >>> 13); d3 &= 0x1fff;
-    d3 += h5 * (5 * r8);
-    d3 += h6 * (5 * r7);
-    d3 += h7 * (5 * r6);
-    d3 += h8 * (5 * r5);
-    d3 += h9 * (5 * r4);
-    c += (d3 >>> 13); d3 &= 0x1fff;
-
-    d4 = c;
-    d4 += h0 * r4;
-    d4 += h1 * r3;
-    d4 += h2 * r2;
-    d4 += h3 * r1;
-    d4 += h4 * r0;
-    c = (d4 >>> 13); d4 &= 0x1fff;
-    d4 += h5 * (5 * r9);
-    d4 += h6 * (5 * r8);
-    d4 += h7 * (5 * r7);
-    d4 += h8 * (5 * r6);
-    d4 += h9 * (5 * r5);
-    c += (d4 >>> 13); d4 &= 0x1fff;
-
-    d5 = c;
-    d5 += h0 * r5;
-    d5 += h1 * r4;
-    d5 += h2 * r3;
-    d5 += h3 * r2;
-    d5 += h4 * r1;
-    c = (d5 >>> 13); d5 &= 0x1fff;
-    d5 += h5 * r0;
-    d5 += h6 * (5 * r9);
-    d5 += h7 * (5 * r8);
-    d5 += h8 * (5 * r7);
-    d5 += h9 * (5 * r6);
-    c += (d5 >>> 13); d5 &= 0x1fff;
-
-    d6 = c;
-    d6 += h0 * r6;
-    d6 += h1 * r5;
-    d6 += h2 * r4;
-    d6 += h3 * r3;
-    d6 += h4 * r2;
-    c = (d6 >>> 13); d6 &= 0x1fff;
-    d6 += h5 * r1;
-    d6 += h6 * r0;
-    d6 += h7 * (5 * r9);
-    d6 += h8 * (5 * r8);
-    d6 += h9 * (5 * r7);
-    c += (d6 >>> 13); d6 &= 0x1fff;
-
-    d7 = c;
-    d7 += h0 * r7;
-    d7 += h1 * r6;
-    d7 += h2 * r5;
-    d7 += h3 * r4;
-    d7 += h4 * r3;
-    c = (d7 >>> 13); d7 &= 0x1fff;
-    d7 += h5 * r2;
-    d7 += h6 * r1;
-    d7 += h7 * r0;
-    d7 += h8 * (5 * r9);
-    d7 += h9 * (5 * r8);
-    c += (d7 >>> 13); d7 &= 0x1fff;
-
-    d8 = c;
-    d8 += h0 * r8;
-    d8 += h1 * r7;
-    d8 += h2 * r6;
-    d8 += h3 * r5;
-    d8 += h4 * r4;
-    c = (d8 >>> 13); d8 &= 0x1fff;
-    d8 += h5 * r3;
-    d8 += h6 * r2;
-    d8 += h7 * r1;
-    d8 += h8 * r0;
-    d8 += h9 * (5 * r9);
-    c += (d8 >>> 13); d8 &= 0x1fff;
-
-    d9 = c;
-    d9 += h0 * r9;
-    d9 += h1 * r8;
-    d9 += h2 * r7;
-    d9 += h3 * r6;
-    d9 += h4 * r5;
-    c = (d9 >>> 13); d9 &= 0x1fff;
-    d9 += h5 * r4;
-    d9 += h6 * r3;
-    d9 += h7 * r2;
-    d9 += h8 * r1;
-    d9 += h9 * r0;
-    c += (d9 >>> 13); d9 &= 0x1fff;
-
-    c = (((c << 2) + c)) | 0;
-    c = (c + d0) | 0;
-    d0 = c & 0x1fff;
-    c = (c >>> 13);
-    d1 += c;
-
-    h0 = d0;
-    h1 = d1;
-    h2 = d2;
-    h3 = d3;
-    h4 = d4;
-    h5 = d5;
-    h6 = d6;
-    h7 = d7;
-    h8 = d8;
-    h9 = d9;
-
-    mpos += 16;
-    bytes -= 16;
-  }
-  this.h[0] = h0;
-  this.h[1] = h1;
-  this.h[2] = h2;
-  this.h[3] = h3;
-  this.h[4] = h4;
-  this.h[5] = h5;
-  this.h[6] = h6;
-  this.h[7] = h7;
-  this.h[8] = h8;
-  this.h[9] = h9;
-};
-
-poly1305.prototype.finish = function(mac, macpos) {
-  var g = new Uint16Array(10);
-  var c, mask, f, i;
-
-  if (this.leftover) {
-    i = this.leftover;
-    this.buffer[i++] = 1;
-    for (; i < 16; i++) this.buffer[i] = 0;
-    this.fin = 1;
-    this.blocks(this.buffer, 0, 16);
+function add1305(h, c) {
+  var j, u = 0;
+  for (j = 0; j < 17; j++) {
+    u = (u + ((h[j] + c[j]) | 0)) | 0;
+    h[j] = u & 255;
+    u >>>= 8;
   }
+}
 
-  c = this.h[1] >>> 13;
-  this.h[1] &= 0x1fff;
-  for (i = 2; i < 10; i++) {
-    this.h[i] += c;
-    c = this.h[i] >>> 13;
-    this.h[i] &= 0x1fff;
-  }
-  this.h[0] += (c * 5);
-  c = this.h[0] >>> 13;
-  this.h[0] &= 0x1fff;
-  this.h[1] += c;
-  c = this.h[1] >>> 13;
-  this.h[1] &= 0x1fff;
-  this.h[2] += c;
-
-  g[0] = this.h[0] + 5;
-  c = g[0] >>> 13;
-  g[0] &= 0x1fff;
-  for (i = 1; i < 10; i++) {
-    g[i] = this.h[i] + c;
-    c = g[i] >>> 13;
-    g[i] &= 0x1fff;
-  }
-  g[9] -= (1 << 13);
-
-  mask = (g[9] >>> ((2 * 8) - 1)) - 1;
-  for (i = 0; i < 10; i++) g[i] &= mask;
-  mask = ~mask;
-  for (i = 0; i < 10; i++) this.h[i] = (this.h[i] & mask) | g[i];
-
-  this.h[0] = ((this.h[0]       ) | (this.h[1] << 13)                    ) & 0xffff;
-  this.h[1] = ((this.h[1] >>>  3) | (this.h[2] << 10)                    ) & 0xffff;
-  this.h[2] = ((this.h[2] >>>  6) | (this.h[3] <<  7)                    ) & 0xffff;
-  this.h[3] = ((this.h[3] >>>  9) | (this.h[4] <<  4)                    ) & 0xffff;
-  this.h[4] = ((this.h[4] >>> 12) | (this.h[5] <<  1) | (this.h[6] << 14)) & 0xffff;
-  this.h[5] = ((this.h[6] >>>  2) | (this.h[7] << 11)                    ) & 0xffff;
-  this.h[6] = ((this.h[7] >>>  5) | (this.h[8] <<  8)                    ) & 0xffff;
-  this.h[7] = ((this.h[8] >>>  8) | (this.h[9] <<  5)                    ) & 0xffff;
-
-  f = this.h[0] + this.pad[0];
-  this.h[0] = f & 0xffff;
-  for (i = 1; i < 8; i++) {
-    f = (((this.h[i] + this.pad[i]) | 0) + (f >>> 16)) | 0;
-    this.h[i] = f & 0xffff;
-  }
-
-  mac[macpos+ 0] = (this.h[0] >>> 0) & 0xff;
-  mac[macpos+ 1] = (this.h[0] >>> 8) & 0xff;
-  mac[macpos+ 2] = (this.h[1] >>> 0) & 0xff;
-  mac[macpos+ 3] = (this.h[1] >>> 8) & 0xff;
-  mac[macpos+ 4] = (this.h[2] >>> 0) & 0xff;
-  mac[macpos+ 5] = (this.h[2] >>> 8) & 0xff;
-  mac[macpos+ 6] = (this.h[3] >>> 0) & 0xff;
-  mac[macpos+ 7] = (this.h[3] >>> 8) & 0xff;
-  mac[macpos+ 8] = (this.h[4] >>> 0) & 0xff;
-  mac[macpos+ 9] = (this.h[4] >>> 8) & 0xff;
-  mac[macpos+10] = (this.h[5] >>> 0) & 0xff;
-  mac[macpos+11] = (this.h[5] >>> 8) & 0xff;
-  mac[macpos+12] = (this.h[6] >>> 0) & 0xff;
-  mac[macpos+13] = (this.h[6] >>> 8) & 0xff;
-  mac[macpos+14] = (this.h[7] >>> 0) & 0xff;
-  mac[macpos+15] = (this.h[7] >>> 8) & 0xff;
-};
-
-poly1305.prototype.update = function(m, mpos, bytes) {
-  var i, want;
-
-  if (this.leftover) {
-    want = (16 - this.leftover);
-    if (want > bytes)
-      want = bytes;
-    for (i = 0; i < want; i++)
-      this.buffer[this.leftover + i] = m[mpos+i];
-    bytes -= want;
-    mpos += want;
-    this.leftover += want;
-    if (this.leftover < 16)
-      return;
-    this.blocks(this.buffer, 0, 16);
-    this.leftover = 0;
-  }
+var minusp = new Uint32Array([
+  5, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 252
+]);
 
-  if (bytes >= 16) {
-    want = bytes - (bytes % 16);
-    this.blocks(m, mpos, want);
-    mpos += want;
-    bytes -= want;
+function crypto_onetimeauth(out, outpos, m, mpos, n, k) {
+  var s, i, j, u;
+  var x = new Uint32Array(17), r = new Uint32Array(17),
+      h = new Uint32Array(17), c = new Uint32Array(17),
+      g = new Uint32Array(17);
+  for (j = 0; j < 17; j++) r[j]=h[j]=0;
+  for (j = 0; j < 16; j++) r[j]=k[j];
+  r[3]&=15;
+  r[4]&=252;
+  r[7]&=15;
+  r[8]&=252;
+  r[11]&=15;
+  r[12]&=252;
+  r[15]&=15;
+
+  while (n > 0) {
+    for (j = 0; j < 17; j++) c[j] = 0;
+    for (j = 0; (j < 16) && (j < n); ++j) c[j] = m[mpos+j];
+    c[j] = 1;
+    mpos += j; n -= j;
+    add1305(h,c);
+    for (i = 0; i < 17; i++) {
+      x[i] = 0;
+      for (j = 0; j < 17; j++) x[i] = (x[i] + (h[j] * ((j <= i) ? r[i - j] : ((320 * r[i + 17 - j])|0))) | 0) | 0;
+    }
+    for (i = 0; i < 17; i++) h[i] = x[i];
+    u = 0;
+    for (j = 0; j < 16; j++) {
+      u = (u + h[j]) | 0;
+      h[j] = u & 255;
+      u >>>= 8;
+    }
+    u = (u + h[16]) | 0; h[16] = u & 3;
+    u = (5 * (u >>> 2)) | 0;
+    for (j = 0; j < 16; j++) {
+      u = (u + h[j]) | 0;
+      h[j] = u & 255;
+      u >>>= 8;
+    }
+    u = (u + h[16]) | 0; h[16] = u;
   }
 
-  if (bytes) {
-    for (i = 0; i < bytes; i++)
-      this.buffer[this.leftover + i] = m[mpos+i];
-    this.leftover += bytes;
-  }
-};
+  for (j = 0; j < 17; j++) g[j] = h[j];
+  add1305(h,minusp);
+  s = (-(h[16] >>> 7) | 0);
+  for (j = 0; j < 17; j++) h[j] ^= s & (g[j] ^ h[j]);
 
-function crypto_onetimeauth(out, outpos, m, mpos, n, k) {
-  var s = new poly1305(k);
-  s.update(m, mpos, n);
-  s.finish(out, outpos);
+  for (j = 0; j < 16; j++) c[j] = k[j + 16];
+  c[16] = 0;
+  add1305(h,c);
+  for (j = 0; j < 16; j++) out[outpos+j] = h[j];
   return 0;
 }