gecko-dev/netwerk/dns/nsIDNService.cpp
2012-09-19 16:59:38 -04:00

677 lines
20 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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 "nsIDNService.h"
#include "nsReadableUtils.h"
#include "nsCRT.h"
#include "nsUnicharUtils.h"
#include "nsIServiceManager.h"
#include "nsIPrefService.h"
#include "nsIPrefBranch.h"
#include "nsIObserverService.h"
#include "nsISupportsPrimitives.h"
#include "punycode.h"
//-----------------------------------------------------------------------------
// RFC 1034 - 3.1. Name space specifications and terminology
static const uint32_t kMaxDNSNodeLen = 63;
//-----------------------------------------------------------------------------
#define NS_NET_PREF_IDNTESTBED "network.IDN_testbed"
#define NS_NET_PREF_IDNPREFIX "network.IDN_prefix"
#define NS_NET_PREF_IDNBLACKLIST "network.IDN.blacklist_chars"
#define NS_NET_PREF_SHOWPUNYCODE "network.IDN_show_punycode"
#define NS_NET_PREF_IDNWHITELIST "network.IDN.whitelist."
inline bool isOnlySafeChars(const nsAFlatString& in,
const nsAFlatString& blacklist)
{
return (blacklist.IsEmpty() ||
in.FindCharInSet(blacklist) == kNotFound);
}
//-----------------------------------------------------------------------------
// nsIDNService
//-----------------------------------------------------------------------------
/* Implementation file */
NS_IMPL_THREADSAFE_ISUPPORTS3(nsIDNService,
nsIIDNService,
nsIObserver,
nsISupportsWeakReference)
nsresult nsIDNService::Init()
{
nsCOMPtr<nsIPrefService> prefs(do_GetService(NS_PREFSERVICE_CONTRACTID));
if (prefs)
prefs->GetBranch(NS_NET_PREF_IDNWHITELIST, getter_AddRefs(mIDNWhitelistPrefBranch));
nsCOMPtr<nsIPrefBranch> prefInternal(do_QueryInterface(prefs));
if (prefInternal) {
prefInternal->AddObserver(NS_NET_PREF_IDNTESTBED, this, true);
prefInternal->AddObserver(NS_NET_PREF_IDNPREFIX, this, true);
prefInternal->AddObserver(NS_NET_PREF_IDNBLACKLIST, this, true);
prefInternal->AddObserver(NS_NET_PREF_SHOWPUNYCODE, this, true);
prefsChanged(prefInternal, nullptr);
}
return NS_OK;
}
NS_IMETHODIMP nsIDNService::Observe(nsISupports *aSubject,
const char *aTopic,
const PRUnichar *aData)
{
if (!strcmp(aTopic, NS_PREFBRANCH_PREFCHANGE_TOPIC_ID)) {
nsCOMPtr<nsIPrefBranch> prefBranch( do_QueryInterface(aSubject) );
if (prefBranch)
prefsChanged(prefBranch, aData);
}
return NS_OK;
}
void nsIDNService::prefsChanged(nsIPrefBranch *prefBranch, const PRUnichar *pref)
{
if (!pref || NS_LITERAL_STRING(NS_NET_PREF_IDNTESTBED).Equals(pref)) {
bool val;
if (NS_SUCCEEDED(prefBranch->GetBoolPref(NS_NET_PREF_IDNTESTBED, &val)))
mMultilingualTestBed = val;
}
if (!pref || NS_LITERAL_STRING(NS_NET_PREF_IDNPREFIX).Equals(pref)) {
nsXPIDLCString prefix;
nsresult rv = prefBranch->GetCharPref(NS_NET_PREF_IDNPREFIX, getter_Copies(prefix));
if (NS_SUCCEEDED(rv) && prefix.Length() <= kACEPrefixLen)
PL_strncpyz(nsIDNService::mACEPrefix, prefix.get(), kACEPrefixLen + 1);
}
if (!pref || NS_LITERAL_STRING(NS_NET_PREF_IDNBLACKLIST).Equals(pref)) {
nsCOMPtr<nsISupportsString> blacklist;
nsresult rv = prefBranch->GetComplexValue(NS_NET_PREF_IDNBLACKLIST,
NS_GET_IID(nsISupportsString),
getter_AddRefs(blacklist));
if (NS_SUCCEEDED(rv))
blacklist->ToString(getter_Copies(mIDNBlacklist));
else
mIDNBlacklist.Truncate();
}
if (!pref || NS_LITERAL_STRING(NS_NET_PREF_SHOWPUNYCODE).Equals(pref)) {
bool val;
if (NS_SUCCEEDED(prefBranch->GetBoolPref(NS_NET_PREF_SHOWPUNYCODE, &val)))
mShowPunycode = val;
}
}
nsIDNService::nsIDNService()
{
// initialize to the official prefix (RFC 3490 "5. ACE prefix")
const char kIDNSPrefix[] = "xn--";
strcpy(mACEPrefix, kIDNSPrefix);
mMultilingualTestBed = false;
if (idn_success != idn_nameprep_create(NULL, &mNamePrepHandle))
mNamePrepHandle = nullptr;
mNormalizer = do_GetService(NS_UNICODE_NORMALIZER_CONTRACTID);
/* member initializers and constructor code */
}
nsIDNService::~nsIDNService()
{
idn_nameprep_destroy(mNamePrepHandle);
}
/* ACString ConvertUTF8toACE (in AUTF8String input); */
NS_IMETHODIMP nsIDNService::ConvertUTF8toACE(const nsACString & input, nsACString & ace)
{
return UTF8toACE(input, ace, true);
}
nsresult nsIDNService::UTF8toACE(const nsACString & input, nsACString & ace, bool allowUnassigned)
{
nsresult rv;
NS_ConvertUTF8toUTF16 ustr(input);
// map ideographic period to ASCII period etc.
normalizeFullStops(ustr);
uint32_t len, offset;
len = 0;
offset = 0;
nsAutoCString encodedBuf;
nsAString::const_iterator start, end;
ustr.BeginReading(start);
ustr.EndReading(end);
ace.Truncate();
// encode nodes if non ASCII
while (start != end) {
len++;
if (*start++ == (PRUnichar)'.') {
rv = stringPrepAndACE(Substring(ustr, offset, len - 1), encodedBuf,
allowUnassigned);
NS_ENSURE_SUCCESS(rv, rv);
ace.Append(encodedBuf);
ace.Append('.');
offset += len;
len = 0;
}
}
// add extra node for multilingual test bed
if (mMultilingualTestBed)
ace.AppendLiteral("mltbd.");
// encode the last node if non ASCII
if (len) {
rv = stringPrepAndACE(Substring(ustr, offset, len), encodedBuf,
allowUnassigned);
NS_ENSURE_SUCCESS(rv, rv);
ace.Append(encodedBuf);
}
return NS_OK;
}
/* AUTF8String convertACEtoUTF8(in ACString input); */
NS_IMETHODIMP nsIDNService::ConvertACEtoUTF8(const nsACString & input, nsACString & _retval)
{
return ACEtoUTF8(input, _retval, true);
}
nsresult nsIDNService::ACEtoUTF8(const nsACString & input, nsACString & _retval,
bool allowUnassigned)
{
// RFC 3490 - 4.2 ToUnicode
// ToUnicode never fails. If any step fails, then the original input
// sequence is returned immediately in that step.
if (!IsASCII(input)) {
_retval.Assign(input);
return NS_OK;
}
uint32_t len = 0, offset = 0;
nsAutoCString decodedBuf;
nsACString::const_iterator start, end;
input.BeginReading(start);
input.EndReading(end);
_retval.Truncate();
// loop and decode nodes
while (start != end) {
len++;
if (*start++ == '.') {
if (NS_FAILED(decodeACE(Substring(input, offset, len - 1), decodedBuf,
allowUnassigned))) {
_retval.Assign(input);
return NS_OK;
}
_retval.Append(decodedBuf);
_retval.Append('.');
offset += len;
len = 0;
}
}
// decode the last node
if (len) {
if (NS_FAILED(decodeACE(Substring(input, offset, len), decodedBuf,
allowUnassigned)))
_retval.Assign(input);
else
_retval.Append(decodedBuf);
}
return NS_OK;
}
/* boolean isACE(in ACString input); */
NS_IMETHODIMP nsIDNService::IsACE(const nsACString & input, bool *_retval)
{
nsACString::const_iterator begin;
input.BeginReading(begin);
const char *data = begin.get();
uint32_t dataLen = begin.size_forward();
// look for the ACE prefix in the input string. it may occur
// at the beginning of any segment in the domain name. for
// example: "www.xn--ENCODED.com"
const char *p = PL_strncasestr(data, mACEPrefix, dataLen);
*_retval = p && (p == data || *(p - 1) == '.');
return NS_OK;
}
/* AUTF8String normalize(in AUTF8String input); */
NS_IMETHODIMP nsIDNService::Normalize(const nsACString & input, nsACString & output)
{
// protect against bogus input
NS_ENSURE_TRUE(IsUTF8(input), NS_ERROR_UNEXPECTED);
NS_ConvertUTF8toUTF16 inUTF16(input);
normalizeFullStops(inUTF16);
// pass the domain name to stringprep label by label
nsAutoString outUTF16, outLabel;
uint32_t len = 0, offset = 0;
nsresult rv;
nsAString::const_iterator start, end;
inUTF16.BeginReading(start);
inUTF16.EndReading(end);
while (start != end) {
len++;
if (*start++ == PRUnichar('.')) {
rv = stringPrep(Substring(inUTF16, offset, len - 1), outLabel, true);
NS_ENSURE_SUCCESS(rv, rv);
outUTF16.Append(outLabel);
outUTF16.Append(PRUnichar('.'));
offset += len;
len = 0;
}
}
if (len) {
rv = stringPrep(Substring(inUTF16, offset, len), outLabel, true);
NS_ENSURE_SUCCESS(rv, rv);
outUTF16.Append(outLabel);
}
CopyUTF16toUTF8(outUTF16, output);
if (!isOnlySafeChars(outUTF16, mIDNBlacklist))
return ConvertUTF8toACE(output, output);
return NS_OK;
}
NS_IMETHODIMP nsIDNService::ConvertToDisplayIDN(const nsACString & input, bool * _isASCII, nsACString & _retval)
{
// If host is ACE, then convert to UTF-8 if the host is in the IDN whitelist.
// Else, if host is already UTF-8, then make sure it is normalized per IDN.
nsresult rv;
if (IsASCII(input)) {
// first, canonicalize the host to lowercase, for whitelist lookup
_retval = input;
ToLowerCase(_retval);
bool isACE;
IsACE(_retval, &isACE);
if (isACE && !mShowPunycode && isInWhitelist(_retval)) {
// ACEtoUTF8() can't fail, but might return the original ACE string
nsAutoCString temp(_retval);
ACEtoUTF8(temp, _retval, false);
*_isASCII = IsASCII(_retval);
} else {
*_isASCII = true;
}
} else {
// We have to normalize the hostname before testing against the domain
// whitelist (see bug 315411), and to ensure the entire string gets
// normalized.
rv = Normalize(input, _retval);
if (NS_FAILED(rv)) return rv;
if (mShowPunycode && NS_SUCCEEDED(ConvertUTF8toACE(_retval, _retval))) {
*_isASCII = true;
return NS_OK;
}
// normalization could result in an ASCII-only hostname. alternatively, if
// the host is converted to ACE by the normalizer, then the host may contain
// unsafe characters, so leave it ACE encoded. see bug 283016, bug 301694, and bug 309311.
*_isASCII = IsASCII(_retval);
if (!*_isASCII && !isInWhitelist(_retval)) {
*_isASCII = true;
return ConvertUTF8toACE(_retval, _retval);
}
}
return NS_OK;
}
//-----------------------------------------------------------------------------
static void utf16ToUcs4(const nsAString& in, uint32_t *out, uint32_t outBufLen, uint32_t *outLen)
{
uint32_t i = 0;
nsAString::const_iterator start, end;
in.BeginReading(start);
in.EndReading(end);
while (start != end) {
PRUnichar curChar;
curChar= *start++;
if (start != end &&
NS_IS_HIGH_SURROGATE(curChar) &&
NS_IS_LOW_SURROGATE(*start)) {
out[i] = SURROGATE_TO_UCS4(curChar, *start);
++start;
}
else
out[i] = curChar;
i++;
if (i >= outBufLen) {
NS_ERROR("input too big, the result truncated");
out[outBufLen-1] = (uint32_t)'\0';
*outLen = outBufLen-1;
return;
}
}
out[i] = (uint32_t)'\0';
*outLen = i;
}
static void ucs4toUtf16(const uint32_t *in, nsAString& out)
{
while (*in) {
if (!IS_IN_BMP(*in)) {
out.Append((PRUnichar) H_SURROGATE(*in));
out.Append((PRUnichar) L_SURROGATE(*in));
}
else
out.Append((PRUnichar) *in);
in++;
}
}
static nsresult punycode(const char* prefix, const nsAString& in, nsACString& out)
{
uint32_t ucs4Buf[kMaxDNSNodeLen + 1];
uint32_t ucs4Len;
utf16ToUcs4(in, ucs4Buf, kMaxDNSNodeLen, &ucs4Len);
// need maximum 20 bits to encode 16 bit Unicode character
// (include null terminator)
const uint32_t kEncodedBufSize = kMaxDNSNodeLen * 20 / 8 + 1 + 1;
char encodedBuf[kEncodedBufSize];
punycode_uint encodedLength = kEncodedBufSize;
enum punycode_status status = punycode_encode(ucs4Len,
ucs4Buf,
nullptr,
&encodedLength,
encodedBuf);
if (punycode_success != status ||
encodedLength >= kEncodedBufSize)
return NS_ERROR_FAILURE;
encodedBuf[encodedLength] = '\0';
out.Assign(nsDependentCString(prefix) + nsDependentCString(encodedBuf));
return NS_OK;
}
static nsresult encodeToRACE(const char* prefix, const nsAString& in, nsACString& out)
{
// need maximum 20 bits to encode 16 bit Unicode character
// (include null terminator)
const uint32_t kEncodedBufSize = kMaxDNSNodeLen * 20 / 8 + 1 + 1;
// set up a work buffer for RACE encoder
PRUnichar temp[kMaxDNSNodeLen + 2];
temp[0] = 0xFFFF; // set a place holder (to be filled by get_compress_mode)
temp[in.Length() + 1] = (PRUnichar)'\0';
nsAString::const_iterator start, end;
in.BeginReading(start);
in.EndReading(end);
for (uint32_t i = 1; start != end; i++)
temp[i] = *start++;
// encode nodes if non ASCII
char encodedBuf[kEncodedBufSize];
idn_result_t result = race_compress_encode((const unsigned short *) temp,
get_compress_mode((unsigned short *) temp + 1),
encodedBuf, kEncodedBufSize);
if (idn_success != result)
return NS_ERROR_FAILURE;
out.Assign(prefix);
out.Append(encodedBuf);
return NS_OK;
}
// RFC 3454
//
// 1) Map -- For each character in the input, check if it has a mapping
// and, if so, replace it with its mapping. This is described in section 3.
//
// 2) Normalize -- Possibly normalize the result of step 1 using Unicode
// normalization. This is described in section 4.
//
// 3) Prohibit -- Check for any characters that are not allowed in the
// output. If any are found, return an error. This is described in section
// 5.
//
// 4) Check bidi -- Possibly check for right-to-left characters, and if any
// are found, make sure that the whole string satisfies the requirements
// for bidirectional strings. If the string does not satisfy the requirements
// for bidirectional strings, return an error. This is described in section 6.
//
// 5) Check unassigned code points -- If allowUnassigned is false, check for
// any unassigned Unicode points and if any are found return an error.
// This is described in section 7.
//
nsresult nsIDNService::stringPrep(const nsAString& in, nsAString& out,
bool allowUnassigned)
{
if (!mNamePrepHandle || !mNormalizer)
return NS_ERROR_FAILURE;
nsresult rv = NS_OK;
uint32_t ucs4Buf[kMaxDNSNodeLen + 1];
uint32_t ucs4Len;
utf16ToUcs4(in, ucs4Buf, kMaxDNSNodeLen, &ucs4Len);
// map
idn_result_t idn_err;
uint32_t namePrepBuf[kMaxDNSNodeLen * 3]; // map up to three characters
idn_err = idn_nameprep_map(mNamePrepHandle, (const uint32_t *) ucs4Buf,
(uint32_t *) namePrepBuf, kMaxDNSNodeLen * 3);
NS_ENSURE_TRUE(idn_err == idn_success, NS_ERROR_FAILURE);
nsAutoString namePrepStr;
ucs4toUtf16(namePrepBuf, namePrepStr);
if (namePrepStr.Length() >= kMaxDNSNodeLen)
return NS_ERROR_FAILURE;
// normalize
nsAutoString normlizedStr;
rv = mNormalizer->NormalizeUnicodeNFKC(namePrepStr, normlizedStr);
if (normlizedStr.Length() >= kMaxDNSNodeLen)
return NS_ERROR_FAILURE;
// prohibit
const uint32_t *found = nullptr;
idn_err = idn_nameprep_isprohibited(mNamePrepHandle,
(const uint32_t *) ucs4Buf, &found);
if (idn_err != idn_success || found)
return NS_ERROR_FAILURE;
// check bidi
idn_err = idn_nameprep_isvalidbidi(mNamePrepHandle,
(const uint32_t *) ucs4Buf, &found);
if (idn_err != idn_success || found)
return NS_ERROR_FAILURE;
if (!allowUnassigned) {
// check unassigned code points
idn_err = idn_nameprep_isunassigned(mNamePrepHandle,
(const uint32_t *) ucs4Buf, &found);
if (idn_err != idn_success || found)
return NS_ERROR_FAILURE;
}
// set the result string
out.Assign(normlizedStr);
return rv;
}
nsresult nsIDNService::encodeToACE(const nsAString& in, nsACString& out)
{
// RACE encode is supported for existing testing environment
if (!strcmp("bq--", mACEPrefix))
return encodeToRACE(mACEPrefix, in, out);
// use punycoce
return punycode(mACEPrefix, in, out);
}
nsresult nsIDNService::stringPrepAndACE(const nsAString& in, nsACString& out,
bool allowUnassigned)
{
nsresult rv = NS_OK;
out.Truncate();
if (in.Length() > kMaxDNSNodeLen) {
NS_WARNING("IDN node too large");
return NS_ERROR_FAILURE;
}
if (IsASCII(in))
LossyCopyUTF16toASCII(in, out);
else {
nsAutoString strPrep;
rv = stringPrep(in, strPrep, allowUnassigned);
if (NS_SUCCEEDED(rv)) {
if (IsASCII(strPrep))
LossyCopyUTF16toASCII(strPrep, out);
else
rv = encodeToACE(strPrep, out);
}
}
if (out.Length() > kMaxDNSNodeLen) {
NS_WARNING("IDN node too large");
return NS_ERROR_FAILURE;
}
return rv;
}
// RFC 3490
// 1) Whenever dots are used as label separators, the following characters
// MUST be recognized as dots: U+002E (full stop), U+3002 (ideographic full
// stop), U+FF0E (fullwidth full stop), U+FF61 (halfwidth ideographic full
// stop).
void nsIDNService::normalizeFullStops(nsAString& s)
{
nsAString::const_iterator start, end;
s.BeginReading(start);
s.EndReading(end);
int32_t index = 0;
while (start != end) {
switch (*start) {
case 0x3002:
case 0xFF0E:
case 0xFF61:
s.Replace(index, 1, NS_LITERAL_STRING("."));
break;
default:
break;
}
start++;
index++;
}
}
nsresult nsIDNService::decodeACE(const nsACString& in, nsACString& out,
bool allowUnassigned)
{
bool isAce;
IsACE(in, &isAce);
if (!isAce) {
out.Assign(in);
return NS_OK;
}
// RFC 3490 - 4.2 ToUnicode
// The ToUnicode output never contains more code points than its input.
punycode_uint output_length = in.Length() - kACEPrefixLen + 1;
punycode_uint *output = new punycode_uint[output_length];
NS_ENSURE_TRUE(output, NS_ERROR_OUT_OF_MEMORY);
enum punycode_status status = punycode_decode(in.Length() - kACEPrefixLen,
PromiseFlatCString(in).get() + kACEPrefixLen,
&output_length,
output,
nullptr);
if (status != punycode_success) {
delete [] output;
return NS_ERROR_FAILURE;
}
// UCS4 -> UTF8
output[output_length] = 0;
nsAutoString utf16;
ucs4toUtf16(output, utf16);
delete [] output;
if (!isOnlySafeChars(utf16, mIDNBlacklist))
return NS_ERROR_FAILURE;
CopyUTF16toUTF8(utf16, out);
// Validation: encode back to ACE and compare the strings
nsAutoCString ace;
nsresult rv = UTF8toACE(out, ace, allowUnassigned);
NS_ENSURE_SUCCESS(rv, rv);
if (!ace.Equals(in, nsCaseInsensitiveCStringComparator()))
return NS_ERROR_FAILURE;
return NS_OK;
}
bool nsIDNService::isInWhitelist(const nsACString &host)
{
if (mIDNWhitelistPrefBranch) {
nsAutoCString tld(host);
// make sure the host is ACE for lookup and check that there are no
// unassigned codepoints
if (!IsASCII(tld) && NS_FAILED(UTF8toACE(tld, tld, false))) {
return false;
}
// truncate trailing dots first
tld.Trim(".");
int32_t pos = tld.RFind(".");
if (pos == kNotFound)
return false;
tld.Cut(0, pos + 1);
bool safe;
if (NS_SUCCEEDED(mIDNWhitelistPrefBranch->GetBoolPref(tld.get(), &safe)))
return safe;
}
return false;
}