From cf1db4f3043fce0474c421dc547b8bd2f9616354 Mon Sep 17 00:00:00 2001
From: Ryan Dahl <ry@tinyclouds.org>
Date: Mon, 18 Oct 2010 11:15:20 -0700
Subject: [PATCH] base64 decode should handle whitespace

---
 lib/buffer.js              |  2 +-
 src/node_buffer.cc         | 60 ++++++++++++++++++++++++++------------
 test/simple/test-buffer.js | 19 ++++++++++++
 3 files changed, 62 insertions(+), 19 deletions(-)

diff --git a/lib/buffer.js b/lib/buffer.js
index ecb25b7e57..e5539581d5 100644
--- a/lib/buffer.js
+++ b/lib/buffer.js
@@ -145,7 +145,7 @@ function Buffer (subject, encoding, offset) {
       }
     } else if (type == 'string') {
       // We are a string
-      this.write(subject, 0, encoding);
+      this.length = this.write(subject, 0, encoding);
     }
   }
 
diff --git a/src/node_buffer.cc b/src/node_buffer.cc
index 5c4e3c1bfe..3f254081f5 100644
--- a/src/node_buffer.cc
+++ b/src/node_buffer.cc
@@ -222,15 +222,16 @@ static const char *base64_table = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
                                   "abcdefghijklmnopqrstuvwxyz"
                                   "0123456789+/";
 static const int unbase64_table[] =
-  {-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1
+  {-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-2,-1,-1,-2,-1,-1
   ,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1
-  ,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,62,-1,-1,-1,63
+  ,-2,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,62,-1,-1,-1,63
   ,52,53,54,55,56,57,58,59,60,61,-1,-1,-1,-1,-1,-1
   ,-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10,11,12,13,14
   ,15,16,17,18,19,20,21,22,23,24,25,-1,-1,-1,-1,-1
   ,-1,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40
   ,41,42,43,44,45,46,47,48,49,50,51,-1,-1,-1,-1,-1
   };
+#define unbase64(x) unbase64_table[(int)(x)]
 
 
 Handle<Value> Buffer::Base64Slice(const Arguments &args) {
@@ -436,16 +437,21 @@ Handle<Value> Buffer::AsciiWrite(const Arguments &args) {
   return scope.Close(Integer::New(written));
 }
 
+
 // var bytesWritten = buffer.base64Write(string, offset, [maxLength]);
 Handle<Value> Buffer::Base64Write(const Arguments &args) {
   HandleScope scope;
 
-  assert(unbase64_table[(int)'/'] == 63);
-  assert(unbase64_table[(int)'+'] == 62);
-  assert(unbase64_table[(int)'T'] == 19);
-  assert(unbase64_table[(int)'Z'] == 25);
-  assert(unbase64_table[(int)'t'] == 45);
-  assert(unbase64_table[(int)'z'] == 51);
+  assert(unbase64('/') == 63);
+  assert(unbase64('+') == 62);
+  assert(unbase64('T') == 19);
+  assert(unbase64('Z') == 25);
+  assert(unbase64('t') == 45);
+  assert(unbase64('z') == 51);
+
+  assert(unbase64(' ') == -2);
+  assert(unbase64('\n') == -2);
+  assert(unbase64('\r') == -2);
 
   Buffer *buffer = ObjectWrap::Unwrap<Buffer>(args.This());
 
@@ -475,29 +481,47 @@ Handle<Value> Buffer::Base64Write(const Arguments &args) {
   }
 
   char a, b, c, d;
-  char* dst = buffer->data_ + offset;
+  char* start = buffer->data_ + offset;
+  char* dst = start;
   const char *src = *s;
   const char *const srcEnd = src + s.length();
 
   while (src < srcEnd) {
-    const int remaining = srcEnd - src;
+    int remaining = srcEnd - src;
+
+    while (unbase64(*src) < 0 && src < srcEnd) {
+      src++;
+      remaining--;
+    }
     if (remaining == 0 || *src == '=') break;
-    a = unbase64_table[(int)*src++];
+    a = unbase64(*src++);
 
-    if (remaining == 1 || *src == '=') break;
-    b = unbase64_table[(int)*src++];
+    while (unbase64(*src) < 0 && src < srcEnd) {
+      src++;
+      remaining--;
+    }
+    if (remaining <= 1 || *src == '=') break;
+    b = unbase64(*src++);
     *dst++ = (a << 2) | ((b & 0x30) >> 4);
 
-    if (remaining == 2 || *src == '=') break;
-    c = unbase64_table[(int)*src++];
+    while (unbase64(*src) < 0 && src < srcEnd) {
+      src++;
+      remaining--;
+    }
+    if (remaining <= 2 || *src == '=') break;
+    c = unbase64(*src++);
     *dst++ = ((b & 0x0F) << 4) | ((c & 0x3C) >> 2);
 
-    if (remaining == 3 || *src == '=') break;
-    d = unbase64_table[(int)*src++];
+    while (unbase64(*src) < 0 && src < srcEnd) {
+      src++;
+      remaining--;
+    }
+    if (remaining <= 3 || *src == '=') break;
+    d = unbase64(*src++);
     *dst++ = ((c & 0x03) << 6) | (d & 0x3F);
   }
 
-  return scope.Close(Integer::New(size));
+  return scope.Close(Integer::New(dst - start));
 }
 
 
diff --git a/test/simple/test-buffer.js b/test/simple/test-buffer.js
index 78a2106a4a..512aea5970 100644
--- a/test/simple/test-buffer.js
+++ b/test/simple/test-buffer.js
@@ -238,6 +238,25 @@ bytesWritten = b.write(expected, 0, 'base64');
 assert.equal(quote.length, bytesWritten);
 assert.equal(quote, b.toString('ascii', 0, quote.length));
 
+// check that the base64 decoder ignores whitespace
+var expectedWhite = expected.slice(0, 60) + " \n" +
+                    expected.slice(60, 120) + " \n" +
+                    expected.slice(120, 180) + " \n" +
+                    expected.slice(180, 240) + " \n" +
+                    expected.slice(240, 300) + "\n" +
+                    expected.slice(300, 360) + "\n";
+b = new Buffer(1024);
+bytesWritten = b.write(expectedWhite, 0, 'base64');
+assert.equal(quote.length, bytesWritten);
+assert.equal(quote, b.toString('ascii', 0, quote.length));
+
+// check that the base64 decoder on the constructor works
+// even in the presence of whitespace.
+b = new Buffer(expectedWhite, 'base64');
+assert.equal(quote.length, b.length);
+assert.equal(quote, b.toString('ascii', 0, quote.length));
+
+
 assert.equal(new Buffer('', 'base64').toString(), '');
 assert.equal(new Buffer('K', 'base64').toString(), '');