The Tor Browser: js/src/vm/CharacterEncoding.cpp@129ffea94266 (annotated)

js/src/vm/CharacterEncoding.cpp@129ffea94266 (annotated)

js/src/vm/CharacterEncoding.cpp

Sat, 03 Jan 2015 20:18:00 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Sat, 03 Jan 2015 20:18:00 +0100
branch: TOR_BUG_3246
changeset 7: 129ffea94266
permissions: -rw-r--r--

Conditionally enable double key logic according to:
private browsing mode or privacy.thirdparty.isolate preference and
implement in GetCookieStringCommon and FindCookie where it counts...
With some reservations of how to convince FindCookie users to test
condition and pass a nullptr when disabling double key logic.

 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
  * vim: set ts=8 sts=4 et sw=4 tw=99:
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #include "js/CharacterEncoding.h"
 #include "jscntxt.h"
 #include "jsprf.h"
 using namespace JS;
 Latin1CharsZ
 JS::LossyTwoByteCharsToNewLatin1CharsZ(js::ThreadSafeContext *cx, TwoByteChars tbchars)
 {
     JS_ASSERT(cx);
     size_t len = tbchars.length();
     unsigned char *latin1 = cx->pod_malloc<unsigned char>(len + 1);
     if (!latin1)
         return Latin1CharsZ();
     for (size_t i = 0; i < len; ++i)
         latin1[i] = static_cast<unsigned char>(tbchars[i]);
     latin1[len] = '\0';
     return Latin1CharsZ(latin1, len);
 }
 static size_t
 GetDeflatedUTF8StringLength(const jschar *chars, size_t nchars)
 {
     size_t nbytes;
     const jschar *end;
     unsigned c, c2;
     nbytes = nchars;
     for (end = chars + nchars; chars != end; chars++) {
         c = *chars;
         if (c < 0x80)
             continue;
         if (0xD800 <= c && c <= 0xDFFF) {
             /* nbytes sets 1 length since this is surrogate pair. */
             if (c >= 0xDC00 || (chars + 1) == end) {
                 nbytes += 2; /* Bad Surrogate */
                 continue;
             }
             c2 = chars[1];
             if (c2 < 0xDC00 || c2 > 0xDFFF) {
                 nbytes += 2; /* Bad Surrogate */
                 continue;
             }
             c = ((c - 0xD800) << 10) + (c2 - 0xDC00) + 0x10000;
             nbytes--;
             chars++;
         }
         c >>= 11;
         nbytes++;
         while (c) {
             c >>= 5;
             nbytes++;
         }
     }
     return nbytes;
 }
 static bool
 PutUTF8ReplacementCharacter(char **dst, size_t *dstlenp) {
     if (*dstlenp < 3)
         return false;
     *(*dst)++ = (char) 0xEF;
     *(*dst)++ = (char) 0xBF;
     *(*dst)++ = (char) 0xBD;
     *dstlenp -= 3;
     return true;
 }
 /*
  * Write up to |*dstlenp| bytes into |dst|.  Writes the number of bytes used
  * into |*dstlenp| on success.  Returns false on failure.
  */
 static bool
 DeflateStringToUTF8Buffer(js::ThreadSafeContext *cx, const jschar *src, size_t srclen,
                           char *dst, size_t *dstlenp)
 {
     size_t dstlen = *dstlenp;
     size_t origDstlen = dstlen;
     while (srclen) {
         uint32_t v;
         jschar c = *src++;
         srclen--;
         if (c >= 0xDC00 && c <= 0xDFFF) {
             if (!PutUTF8ReplacementCharacter(&dst, &dstlen))
                 goto bufferTooSmall;
             continue;
         } else if (c < 0xD800 || c > 0xDBFF) {
             v = c;
         } else {
             if (srclen < 1) {
                 if (!PutUTF8ReplacementCharacter(&dst, &dstlen))
                     goto bufferTooSmall;
                 continue;
             }
             jschar c2 = *src;
             if ((c2 < 0xDC00) || (c2 > 0xDFFF)) {
                 if (!PutUTF8ReplacementCharacter(&dst, &dstlen))
                     goto bufferTooSmall;
                 continue;
             }
             src++;
             srclen--;
             v = ((c - 0xD800) << 10) + (c2 - 0xDC00) + 0x10000;
         }
         size_t utf8Len;
         if (v < 0x0080) {
             /* no encoding necessary - performance hack */
             if (dstlen == 0)
                 goto bufferTooSmall;
             *dst++ = (char) v;
             utf8Len = 1;
         } else {
             uint8_t utf8buf[4];
             utf8Len = js_OneUcs4ToUtf8Char(utf8buf, v);
             if (utf8Len > dstlen)
                 goto bufferTooSmall;
             for (size_t i = 0; i < utf8Len; i++)
                 *dst++ = (char) utf8buf[i];
         }
         dstlen -= utf8Len;
     }
     *dstlenp = (origDstlen - dstlen);
     return true;
 bufferTooSmall:
     *dstlenp = (origDstlen - dstlen);
     if (cx->isJSContext())
         JS_ReportErrorNumber(cx->asJSContext(), js_GetErrorMessage, nullptr,
                              JSMSG_BUFFER_TOO_SMALL);
     return false;
 }
 UTF8CharsZ
 JS::TwoByteCharsToNewUTF8CharsZ(js::ThreadSafeContext *cx, TwoByteChars tbchars)
 {
     JS_ASSERT(cx);
     /* Get required buffer size. */
     jschar *str = tbchars.start().get();
     size_t len = GetDeflatedUTF8StringLength(str, tbchars.length());
     /* Allocate buffer. */
     unsigned char *utf8 = cx->pod_malloc<unsigned char>(len + 1);
     if (!utf8)
         return UTF8CharsZ();
     /* Encode to UTF8. */
     DeflateStringToUTF8Buffer(cx, str, tbchars.length(), (char *)utf8, &len);
     utf8[len] = '\0';
     return UTF8CharsZ(utf8, len);
 }
 static const uint32_t INVALID_UTF8 = UINT32_MAX;
 /*
  * Convert a utf8 character sequence into a UCS-4 character and return that
  * character.  It is assumed that the caller already checked that the sequence
  * is valid.
  */
 uint32_t
 JS::Utf8ToOneUcs4Char(const uint8_t *utf8Buffer, int utf8Length)
 {
     JS_ASSERT(1 <= utf8Length && utf8Length <= 4);
     if (utf8Length == 1) {
         JS_ASSERT(!(*utf8Buffer & 0x80));
         return *utf8Buffer;
     }
     /* from Unicode 3.1, non-shortest form is illegal */
     static const uint32_t minucs4Table[] = { 0x80, 0x800, 0x10000 };
     JS_ASSERT((*utf8Buffer & (0x100 - (1 << (7 - utf8Length)))) ==
               (0x100 - (1 << (8 - utf8Length))));
     uint32_t ucs4Char = *utf8Buffer++ & ((1 << (7 - utf8Length)) - 1);
     uint32_t minucs4Char = minucs4Table[utf8Length - 2];
     while (--utf8Length) {
         JS_ASSERT((*utf8Buffer & 0xC0) == 0x80);
         ucs4Char = (ucs4Char << 6) | (*utf8Buffer++ & 0x3F);
     }
     if (MOZ_UNLIKELY(ucs4Char < minucs4Char || (ucs4Char >= 0xD800 && ucs4Char <= 0xDFFF)))
         return INVALID_UTF8;
     return ucs4Char;
 }
 static void
 ReportInvalidCharacter(JSContext *cx, uint32_t offset)
 {
     char buffer[10];
     JS_snprintf(buffer, 10, "%d", offset);
     JS_ReportErrorFlagsAndNumber(cx, JSREPORT_ERROR, js_GetErrorMessage, nullptr,
                                  JSMSG_MALFORMED_UTF8_CHAR, buffer);
 }
 static void
 ReportBufferTooSmall(JSContext *cx, uint32_t dummy)
 {
     JS_ReportErrorNumber(cx, js_GetErrorMessage, nullptr, JSMSG_BUFFER_TOO_SMALL);
 }
 static void
 ReportTooBigCharacter(JSContext *cx, uint32_t v)
 {
     char buffer[10];
     JS_snprintf(buffer, 10, "0x%x", v + 0x10000);
     JS_ReportErrorFlagsAndNumber(cx, JSREPORT_ERROR, js_GetErrorMessage, nullptr,
                                  JSMSG_UTF8_CHAR_TOO_LARGE, buffer);
 }
 enum InflateUTF8Action {
     CountAndReportInvalids,
     CountAndIgnoreInvalids,
     Copy
 };
 static const uint32_t REPLACE_UTF8 = 0xFFFD;
 // If making changes to this algorithm, make sure to also update
 // LossyConvertUTF8toUTF16() in dom/wifi/WifiUtils.cpp
 template <InflateUTF8Action action>
 static bool
 InflateUTF8StringToBuffer(JSContext *cx, const UTF8Chars src, jschar *dst, size_t *dstlenp,
                           bool *isAsciip)
 {
     *isAsciip = true;
     // First, count how many jschars need to be in the inflated string.
     // |i| is the index into |src|, and |j| is the the index into |dst|.
     size_t srclen = src.length();
     uint32_t j = 0;
     for (uint32_t i = 0; i < srclen; i++, j++) {
         uint32_t v = uint32_t(src[i]);
         if (!(v & 0x80)) {
             // ASCII code unit.  Simple copy.
             if (action == Copy)
                 dst[j] = jschar(v);
         } else {
             // Non-ASCII code unit.  Determine its length in bytes (n).
             *isAsciip = false;
             uint32_t n = 1;
             while (v & (0x80 >> n))
                 n++;
         #define INVALID(report, arg, n2)                                \
             do {                                                        \
                 if (action == CountAndReportInvalids) {                 \
                     report(cx, arg);                                    \
                     return false;                                       \
                 } else {                                                \
                     if (action == Copy)                                 \
                         dst[j] = jschar(REPLACE_UTF8);                  \
                     else                                                \
                         JS_ASSERT(action == CountAndIgnoreInvalids);    \
                     n = n2;                                             \
                     goto invalidMultiByteCodeUnit;                      \
                 }                                                       \
             } while (0)
             // Check the leading byte.
             if (n < 2 || n > 4)
                 INVALID(ReportInvalidCharacter, i, 1);
             // Check that |src| is large enough to hold an n-byte code unit.
             if (i + n > srclen)
                 INVALID(ReportBufferTooSmall, /* dummy = */ 0, 1);
             // Check the second byte.  From Unicode Standard v6.2, Table 3-7
             // Well-Formed UTF-8 Byte Sequences.
             if ((v == 0xE0 && ((uint8_t)src[i + 1] & 0xE0) != 0xA0) ||  // E0 A0~BF
                 (v == 0xED && ((uint8_t)src[i + 1] & 0xE0) != 0x80) ||  // ED 80~9F
                 (v == 0xF0 && ((uint8_t)src[i + 1] & 0xF0) == 0x80) ||  // F0 90~BF
                 (v == 0xF4 && ((uint8_t)src[i + 1] & 0xF0) != 0x80))    // F4 80~8F
             {
                 INVALID(ReportInvalidCharacter, i, 1);
             }
             // Check the continuation bytes.
             for (uint32_t m = 1; m < n; m++)
                 if ((src[i + m] & 0xC0) != 0x80)
                     INVALID(ReportInvalidCharacter, i, m);
             // Determine the code unit's length in jschars and act accordingly.
             v = Utf8ToOneUcs4Char((uint8_t *)&src[i], n);
             if (v < 0x10000) {
                 // The n-byte UTF8 code unit will fit in a single jschar.
                 if (action == Copy)
                     dst[j] = jschar(v);
             } else {
                 v -= 0x10000;
                 if (v <= 0xFFFFF) {
                     // The n-byte UTF8 code unit will fit in two jschars.
                     if (action == Copy)
                         dst[j] = jschar((v >> 10) + 0xD800);
                     j++;
                     if (action == Copy)
                         dst[j] = jschar((v & 0x3FF) + 0xDC00);
                 } else {
                     // The n-byte UTF8 code unit won't fit in two jschars.
                     INVALID(ReportTooBigCharacter, v, 1);
                 }
             }
           invalidMultiByteCodeUnit:
             // Move i to the last byte of the multi-byte code unit;  the loop
             // header will do the final i++ to move to the start of the next
             // code unit.
             i += n - 1;
         }
     }
     *dstlenp = j;
     return true;
 }
 typedef bool (*CountAction)(JSContext *, const UTF8Chars, jschar *, size_t *, bool *isAsciip);
 static TwoByteCharsZ
 InflateUTF8StringHelper(JSContext *cx, const UTF8Chars src, CountAction countAction, size_t *outlen)
 {
     *outlen = 0;
     bool isAscii;
     if (!countAction(cx, src, /* dst = */ nullptr, outlen, &isAscii))
         return TwoByteCharsZ();
     jschar *dst = cx->pod_malloc<jschar>(*outlen + 1);  // +1 for NUL
     if (!dst)
         return TwoByteCharsZ();
     if (isAscii) {
         size_t srclen = src.length();
         JS_ASSERT(*outlen == srclen);
         for (uint32_t i = 0; i < srclen; i++)
             dst[i] = jschar(src[i]);
     } else {
         JS_ALWAYS_TRUE(InflateUTF8StringToBuffer<Copy>(cx, src, dst, outlen, &isAscii));
     }
     dst[*outlen] = 0;    // NUL char
     return TwoByteCharsZ(dst, *outlen);
 }
 TwoByteCharsZ
 JS::UTF8CharsToNewTwoByteCharsZ(JSContext *cx, const UTF8Chars utf8, size_t *outlen)
 {
     return InflateUTF8StringHelper(cx, utf8, InflateUTF8StringToBuffer<CountAndReportInvalids>,
                                    outlen);
 }
 TwoByteCharsZ
 JS::LossyUTF8CharsToNewTwoByteCharsZ(JSContext *cx, const UTF8Chars utf8, size_t *outlen)
 {
     return InflateUTF8StringHelper(cx, utf8, InflateUTF8StringToBuffer<CountAndIgnoreInvalids>,
                                    outlen);
 }

The Tor Browser / annotate

js/src/vm/CharacterEncoding.cpp@129ffea94266 (annotated)

js/src/vm/CharacterEncoding.cpp