gecko/netwerk/mime/nsMIMEHeaderParamImpl.cpp

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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:expandtab:shiftwidth=2:tabstop=4:
*/
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is mozilla.org code.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* rhp@netscape.com
* Jungshik Shin <jshin@mailaps.org>
* John G Myers <jgmyers@netscape.com>
* Takayuki Tei <taka@netscape.com>
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#include <string.h>
#include "prtypes.h"
#include "prmem.h"
#include "prprf.h"
#include "plstr.h"
#include "plbase64.h"
#include "nsCRT.h"
#include "nsMemory.h"
#include "nsCOMPtr.h"
#include "nsEscape.h"
#include "nsIUTF8ConverterService.h"
#include "nsUConvCID.h"
#include "nsIServiceManager.h"
#include "nsMIMEHeaderParamImpl.h"
#include "nsReadableUtils.h"
#include "nsNativeCharsetUtils.h"
#include "nsNetError.h"
// static functions declared below are moved from mailnews/mime/src/comi18n.cpp
static char *DecodeQ(const char *, PRUint32);
static bool Is7bitNonAsciiString(const char *, PRUint32);
static void CopyRawHeader(const char *, PRUint32, const char *, nsACString &);
static nsresult DecodeRFC2047Str(const char *, const char *, bool, nsACString&);
// XXX The chance of UTF-7 being used in the message header is really
// low, but in theory it's possible.
#define IS_7BIT_NON_ASCII_CHARSET(cset) \
(!nsCRT::strncasecmp((cset), "ISO-2022", 8) || \
!nsCRT::strncasecmp((cset), "HZ-GB", 5) || \
!nsCRT::strncasecmp((cset), "UTF-7", 5))
NS_IMPL_ISUPPORTS1(nsMIMEHeaderParamImpl, nsIMIMEHeaderParam)
NS_IMETHODIMP
nsMIMEHeaderParamImpl::GetParameter(const nsACString& aHeaderVal,
const char *aParamName,
const nsACString& aFallbackCharset,
bool aTryLocaleCharset,
char **aLang, nsAString& aResult)
{
return DoGetParameter(aHeaderVal, aParamName, RFC_2231_DECODING,
aFallbackCharset, aTryLocaleCharset, aLang, aResult);
}
NS_IMETHODIMP
nsMIMEHeaderParamImpl::GetParameter5987(const nsACString& aHeaderVal,
const char *aParamName,
const nsACString& aFallbackCharset,
bool aTryLocaleCharset,
char **aLang, nsAString& aResult)
{
return DoGetParameter(aHeaderVal, aParamName, RFC_5987_DECODING,
aFallbackCharset, aTryLocaleCharset, aLang, aResult);
}
// XXX : aTryLocaleCharset is not yet effective.
nsresult
nsMIMEHeaderParamImpl::DoGetParameter(const nsACString& aHeaderVal,
const char *aParamName,
ParamDecoding aDecoding,
const nsACString& aFallbackCharset,
bool aTryLocaleCharset,
char **aLang, nsAString& aResult)
{
aResult.Truncate();
nsresult rv;
// get parameter (decode RFC 2231/5987 when applicable, as specified by
// aDecoding (5987 being a subset of 2231) and return charset.)
nsXPIDLCString med;
nsXPIDLCString charset;
rv = DoParameterInternal(PromiseFlatCString(aHeaderVal).get(), aParamName,
aDecoding, getter_Copies(charset), aLang,
getter_Copies(med));
if (NS_FAILED(rv))
return rv;
// convert to UTF-8 after charset conversion and RFC 2047 decoding
// if necessary.
nsCAutoString str1;
rv = DecodeParameter(med, charset.get(), nsnull, false, str1);
NS_ENSURE_SUCCESS(rv, rv);
if (!aFallbackCharset.IsEmpty())
{
nsCAutoString str2;
nsCOMPtr<nsIUTF8ConverterService>
cvtUTF8(do_GetService(NS_UTF8CONVERTERSERVICE_CONTRACTID));
if (cvtUTF8 &&
NS_SUCCEEDED(cvtUTF8->ConvertStringToUTF8(str1,
PromiseFlatCString(aFallbackCharset).get(), false, str2))) {
CopyUTF8toUTF16(str2, aResult);
return NS_OK;
}
}
if (IsUTF8(str1)) {
CopyUTF8toUTF16(str1, aResult);
return NS_OK;
}
if (aTryLocaleCharset && !NS_IsNativeUTF8())
return NS_CopyNativeToUnicode(str1, aResult);
CopyASCIItoUTF16(str1, aResult);
return NS_OK;
}
// remove backslash-encoded sequences from quoted-strings
// modifies string in place, potentially shortening it
void RemoveQuotedStringEscapes(char *src)
{
char *dst = src;
for (char *c = src; *c; ++c)
{
if (c[0] == '\\' && c[1])
{
// skip backslash if not at end
++c;
}
*dst++ = *c;
}
*dst = 0;
}
// moved almost verbatim from mimehdrs.cpp
// char *
// MimeHeaders_get_parameter (const char *header_value, const char *parm_name,
// char **charset, char **language)
//
// The format of these header lines is
// <token> [ ';' <token> '=' <token-or-quoted-string> ]*
NS_IMETHODIMP
nsMIMEHeaderParamImpl::GetParameterInternal(const char *aHeaderValue,
const char *aParamName,
char **aCharset,
char **aLang,
char **aResult)
{
return DoParameterInternal(aHeaderValue, aParamName, RFC_2231_DECODING,
aCharset, aLang, aResult);
}
nsresult
nsMIMEHeaderParamImpl::DoParameterInternal(const char *aHeaderValue,
const char *aParamName,
ParamDecoding aDecoding,
char **aCharset,
char **aLang,
char **aResult)
{
if (!aHeaderValue || !*aHeaderValue || !aResult)
return NS_ERROR_INVALID_ARG;
*aResult = nsnull;
if (aCharset) *aCharset = nsnull;
if (aLang) *aLang = nsnull;
const char *str = aHeaderValue;
// skip leading white space.
for (; *str && nsCRT::IsAsciiSpace(*str); ++str)
;
const char *start = str;
// aParamName is empty. return the first (possibly) _unnamed_ 'parameter'
// For instance, return 'inline' in the following case:
// Content-Disposition: inline; filename=.....
if (!aParamName || !*aParamName)
{
for (; *str && *str != ';' && !nsCRT::IsAsciiSpace(*str); ++str)
;
if (str == start)
return NS_ERROR_FIRST_HEADER_FIELD_COMPONENT_EMPTY;
*aResult = (char *) nsMemory::Clone(start, (str - start) + 1);
NS_ENSURE_TRUE(*aResult, NS_ERROR_OUT_OF_MEMORY);
(*aResult)[str - start] = '\0'; // null-terminate
return NS_OK;
}
/* Skip forward to first ';' */
for (; *str && *str != ';' && *str != ','; ++str)
;
if (*str)
str++;
/* Skip over following whitespace */
for (; *str && nsCRT::IsAsciiSpace(*str); ++str)
;
// Some broken http servers just specify parameters
// like 'filename' without specifying disposition
// method. Rewind to the first non-white-space
// character.
if (!*str)
str = start;
// RFC2231 - The legitimate parm format can be:
// A. title=ThisIsTitle
// B. title*=us-ascii'en-us'This%20is%20wierd.
// C. title*0*=us-ascii'en'This%20is%20wierd.%20We
// title*1*=have%20to%20support%20this.
// title*2="Else..."
// D. title*0="Hey, what you think you are doing?"
// title*1="There is no charset and lang info."
// RFC5987: only A and B
PRInt32 paramLen = strlen(aParamName);
bool haveCaseAValue = false;
PRInt32 nextContinuation = 0; // next value in series, or -1 if error
while (*str) {
const char *tokenStart = str;
const char *tokenEnd = 0;
const char *valueStart = str;
const char *valueEnd = 0;
bool seenEquals = false;
NS_ASSERTION(!nsCRT::IsAsciiSpace(*str), "should be after whitespace.");
// Skip forward to the end of this token.
for (; *str && !nsCRT::IsAsciiSpace(*str) && *str != '=' && *str != ';'; str++)
;
tokenEnd = str;
// Skip over whitespace, '=', and whitespace
while (nsCRT::IsAsciiSpace(*str)) ++str;
if (*str == '=') {
++str;
seenEquals = true;
}
while (nsCRT::IsAsciiSpace(*str)) ++str;
bool needUnquote = false;
if (*str != '"')
{
// The value is a token, not a quoted string.
valueStart = str;
for (valueEnd = str;
*valueEnd && !nsCRT::IsAsciiSpace (*valueEnd) && *valueEnd != ';';
valueEnd++)
;
str = valueEnd;
}
else
{
// The value is a quoted string.
needUnquote = true;
++str;
valueStart = str;
for (valueEnd = str; *valueEnd; ++valueEnd)
{
if (*valueEnd == '\\')
++valueEnd;
else if (*valueEnd == '"')
break;
}
str = valueEnd;
// *valueEnd != null means that *valueEnd is quote character.
if (*valueEnd)
str++;
}
// See if this is the simplest case (case A above),
// a 'single' line value with no charset and lang.
// If so, copy it and return.
if (tokenEnd - tokenStart == paramLen &&
seenEquals &&
!nsCRT::strncasecmp(tokenStart, aParamName, paramLen))
{
if (*aResult)
{
// either seen earlier caseA value already--we prefer first--or caseA
// came after a continuation: either way, prefer other value
goto increment_str;
}
// if the parameter spans across multiple lines we have to strip out the
// line continuation -- jht 4/29/98
nsCAutoString tempStr(valueStart, valueEnd - valueStart);
tempStr.StripChars("\r\n");
char *res = ToNewCString(tempStr);
NS_ENSURE_TRUE(res, NS_ERROR_OUT_OF_MEMORY);
if (needUnquote)
RemoveQuotedStringEscapes(res);
*aResult = res;
haveCaseAValue = true;
// keep going, we may find a RFC 2231/5987 encoded alternative
}
// case B, C, and D
else if (tokenEnd - tokenStart > paramLen &&
!nsCRT::strncasecmp(tokenStart, aParamName, paramLen) &&
seenEquals &&
*(tokenStart + paramLen) == '*')
{
const char *cp = tokenStart + paramLen + 1; // 1st char past '*'
bool needUnescape = *(tokenEnd - 1) == '*';
bool caseB = (tokenEnd - tokenStart) == paramLen + 1;
bool caseCorDStart = (*cp == '0') && needUnescape;
bool acceptContinuations = (aDecoding != RFC_5987_DECODING);
// CaseB and start of CaseC: requires charset and optional language
// in quotes (quotes required even if lang is blank)
if (caseB || (caseCorDStart && acceptContinuations))
{
if (caseCorDStart) {
if (nextContinuation++ != 0)
{
// error: already started a continuation. Skip future
// continuations and return whatever initial parts were in order.
nextContinuation = -1;
goto increment_str;
}
}
// look for single quotation mark(')
const char *sQuote1 = PL_strchr(valueStart, 0x27);
const char *sQuote2 = (char *) (sQuote1 ? PL_strchr(sQuote1 + 1, 0x27) : nsnull);
// Two single quotation marks must be present even in
// absence of charset and lang.
if (!sQuote1 || !sQuote2)
NS_WARNING("Mandatory two single quotes are missing in header parameter\n");
if (aCharset && sQuote1 > valueStart && sQuote1 < valueEnd)
{
*aCharset = (char *) nsMemory::Clone(valueStart, sQuote1 - valueStart + 1);
if (*aCharset)
*(*aCharset + (sQuote1 - valueStart)) = 0;
}
if (aLang && sQuote1 && sQuote2 && sQuote2 > sQuote1 + 1 &&
sQuote2 < valueEnd)
{
*aLang = (char *) nsMemory::Clone(sQuote1 + 1, sQuote2 - (sQuote1 + 1) + 1);
if (*aLang)
*(*aLang + (sQuote2 - (sQuote1 + 1))) = 0;
}
// Be generous and handle gracefully when required
// single quotes are absent.
if (sQuote1)
{
if(!sQuote2)
sQuote2 = sQuote1;
}
else
sQuote2 = valueStart - 1;
if (sQuote2 && sQuote2 + 1 < valueEnd)
{
if (*aResult)
{
// caseA value already read, or caseC/D value already read
// but we're now reading caseB: either way, drop old value
nsMemory::Free(*aResult);
haveCaseAValue = false;
}
*aResult = (char *) nsMemory::Alloc(valueEnd - (sQuote2 + 1) + 1);
if (*aResult)
{
memcpy(*aResult, sQuote2 + 1, valueEnd - (sQuote2 + 1));
*(*aResult + (valueEnd - (sQuote2 + 1))) = 0;
if (needUnescape)
{
nsUnescape(*aResult);
if (caseB)
return NS_OK; // caseB wins over everything else
}
}
}
} // end of if-block : title*0*= or title*=
// caseD: a line of multiline param with no need for unescaping : title*[0-9]=
// or 2nd or later lines of a caseC param : title*[1-9]*=
else if (acceptContinuations && nsCRT::IsAsciiDigit(PRUnichar(*cp)))
{
PRInt32 nextSegment = atoi(cp);
// no leading zeros allowed except for ... position 0
bool broken = nextSegment > 0 && *cp == '0';
if (broken || nextSegment != nextContinuation++)
{
// error: gap in continuation or unneccessary leading 0.
// Skip future continuations and return whatever initial parts were
// in order.
nextContinuation = -1;
goto increment_str;
}
if (haveCaseAValue && *aResult)
{
// drop caseA value
nsMemory::Free(*aResult);
*aResult = 0;
haveCaseAValue = false;
}
PRInt32 len = 0;
if (*aResult) // 2nd or later lines of multiline parameter
{
len = strlen(*aResult);
char *ns = (char *) nsMemory::Realloc(*aResult, len + (valueEnd - valueStart) + 1);
if (!ns)
{
nsMemory::Free(*aResult);
}
*aResult = ns;
}
else
{
NS_ASSERTION(*cp == '0', "Not first value in continuation"); // must be; 1st line : title*0=
*aResult = (char *) nsMemory::Alloc(valueEnd - valueStart + 1);
}
if (*aResult)
{
// append a partial value
memcpy(*aResult + len, valueStart, valueEnd - valueStart);
*(*aResult + len + (valueEnd - valueStart)) = 0;
if (needUnescape)
nsUnescape(*aResult + len);
}
else
return NS_ERROR_OUT_OF_MEMORY;
} // end of if-block : title*[0-9]= or title*[1-9]*=
}
// str now points after the end of the value.
// skip over whitespace, ';', whitespace.
increment_str:
while (nsCRT::IsAsciiSpace(*str)) ++str;
if (*str == ';') ++str;
while (nsCRT::IsAsciiSpace(*str)) ++str;
}
if (*aResult)
return NS_OK;
else
return NS_ERROR_INVALID_ARG; // aParameter not found !!
}
NS_IMETHODIMP
nsMIMEHeaderParamImpl::DecodeRFC2047Header(const char* aHeaderVal,
const char* aDefaultCharset,
bool aOverrideCharset,
bool aEatContinuations,
nsACString& aResult)
{
aResult.Truncate();
if (!aHeaderVal)
return NS_ERROR_INVALID_ARG;
if (!*aHeaderVal)
return NS_OK;
// If aHeaderVal is RFC 2047 encoded or is not a UTF-8 string but
// aDefaultCharset is specified, decodes RFC 2047 encoding and converts
// to UTF-8. Otherwise, just strips away CRLF.
if (PL_strstr(aHeaderVal, "=?") ||
(aDefaultCharset && (!IsUTF8(nsDependentCString(aHeaderVal)) ||
Is7bitNonAsciiString(aHeaderVal, PL_strlen(aHeaderVal))))) {
DecodeRFC2047Str(aHeaderVal, aDefaultCharset, aOverrideCharset, aResult);
} else if (aEatContinuations &&
(PL_strchr(aHeaderVal, '\n') || PL_strchr(aHeaderVal, '\r'))) {
aResult = aHeaderVal;
} else {
aEatContinuations = false;
aResult = aHeaderVal;
}
if (aEatContinuations) {
nsCAutoString temp(aResult);
temp.ReplaceSubstring("\n\t", " ");
temp.ReplaceSubstring("\r\t", " ");
temp.StripChars("\r\n");
aResult = temp;
}
return NS_OK;
}
NS_IMETHODIMP
nsMIMEHeaderParamImpl::DecodeParameter(const nsACString& aParamValue,
const char* aCharset,
const char* aDefaultCharset,
bool aOverrideCharset,
nsACString& aResult)
{
aResult.Truncate();
// If aCharset is given, aParamValue was obtained from RFC2231/5987
// encoding and we're pretty sure that it's in aCharset.
if (aCharset && *aCharset)
{
nsCOMPtr<nsIUTF8ConverterService> cvtUTF8(do_GetService(NS_UTF8CONVERTERSERVICE_CONTRACTID));
if (cvtUTF8)
// skip ASCIIness/UTF8ness test if aCharset is 7bit non-ascii charset.
return cvtUTF8->ConvertStringToUTF8(aParamValue, aCharset,
IS_7BIT_NON_ASCII_CHARSET(aCharset), aResult);
}
const nsAFlatCString& param = PromiseFlatCString(aParamValue);
nsCAutoString unQuoted;
nsACString::const_iterator s, e;
param.BeginReading(s);
param.EndReading(e);
// strip '\' when used to quote CR, LF, '"' and '\'
for ( ; s != e; ++s) {
if ((*s == '\\')) {
if (++s == e) {
--s; // '\' is at the end. move back and append '\'.
}
else if (*s != nsCRT::CR && *s != nsCRT::LF && *s != '"' && *s != '\\') {
--s; // '\' is not foll. by CR,LF,'"','\'. move back and append '\'
}
// else : skip '\' and append the quoted character.
}
unQuoted.Append(*s);
}
aResult = unQuoted;
nsCAutoString decoded;
// Try RFC 2047 encoding, instead.
nsresult rv = DecodeRFC2047Header(unQuoted.get(), aDefaultCharset,
aOverrideCharset, true, decoded);
if (NS_SUCCEEDED(rv) && !decoded.IsEmpty())
aResult = decoded;
return rv;
}
#define ISHEXCHAR(c) \
((0x30 <= PRUint8(c) && PRUint8(c) <= 0x39) || \
(0x41 <= PRUint8(c) && PRUint8(c) <= 0x46) || \
(0x61 <= PRUint8(c) && PRUint8(c) <= 0x66))
// Decode Q encoding (RFC 2047).
// static
char *DecodeQ(const char *in, PRUint32 length)
{
char *out, *dest = 0;
out = dest = (char *)PR_Calloc(length + 1, sizeof(char));
if (dest == nsnull)
return nsnull;
while (length > 0) {
PRUintn c = 0;
switch (*in) {
case '=':
// check if |in| in the form of '=hh' where h is [0-9a-fA-F].
if (length < 3 || !ISHEXCHAR(in[1]) || !ISHEXCHAR(in[2]))
goto badsyntax;
PR_sscanf(in + 1, "%2X", &c);
*out++ = (char) c;
in += 3;
length -= 3;
break;
case '_':
*out++ = ' ';
in++;
length--;
break;
default:
if (*in & 0x80) goto badsyntax;
*out++ = *in++;
length--;
}
}
*out++ = '\0';
for (out = dest; *out ; ++out) {
if (*out == '\t')
*out = ' ';
}
return dest;
badsyntax:
PR_Free(dest);
return nsnull;
}
// check if input is HZ (a 7bit encoding for simplified Chinese : RFC 1842))
// or has ESC which may be an indication that it's in one of many ISO
// 2022 7bit encodings (e.g. ISO-2022-JP(-2)/CN : see RFC 1468, 1922, 1554).
// static
bool Is7bitNonAsciiString(const char *input, PRUint32 len)
{
PRInt32 c;
enum { hz_initial, // No HZ seen yet
hz_escaped, // Inside an HZ ~{ escape sequence
hz_seen, // Have seen at least one complete HZ sequence
hz_notpresent // Have seen something that is not legal HZ
} hz_state;
hz_state = hz_initial;
while (len) {
c = PRUint8(*input++);
len--;
if (c & 0x80) return false;
if (c == 0x1B) return true;
if (c == '~') {
switch (hz_state) {
case hz_initial:
case hz_seen:
if (*input == '{') {
hz_state = hz_escaped;
} else if (*input == '~') {
// ~~ is the HZ encoding of ~. Skip over second ~ as well
hz_state = hz_seen;
input++;
len--;
} else {
hz_state = hz_notpresent;
}
break;
case hz_escaped:
if (*input == '}') hz_state = hz_seen;
break;
default:
break;
}
}
}
return hz_state == hz_seen;
}
#define REPLACEMENT_CHAR "\357\277\275" // EF BF BD (UTF-8 encoding of U+FFFD)
// copy 'raw' sequences of octets in aInput to aOutput.
// If aDefaultCharset is specified, the input is assumed to be in the
// charset and converted to UTF-8. Otherwise, a blind copy is made.
// If aDefaultCharset is specified, but the conversion to UTF-8
// is not successful, each octet is replaced by Unicode replacement
// chars. *aOutput is advanced by the number of output octets.
// static
void CopyRawHeader(const char *aInput, PRUint32 aLen,
const char *aDefaultCharset, nsACString &aOutput)
{
PRInt32 c;
// If aDefaultCharset is not specified, make a blind copy.
if (!aDefaultCharset || !*aDefaultCharset) {
aOutput.Append(aInput, aLen);
return;
}
// Copy as long as it's US-ASCII. An ESC may indicate ISO 2022
// A ~ may indicate it is HZ
while (aLen && (c = PRUint8(*aInput++)) != 0x1B && c != '~' && !(c & 0x80)) {
aOutput.Append(char(c));
aLen--;
}
if (!aLen) {
return;
}
aInput--;
// skip ASCIIness/UTF8ness test if aInput is supected to be a 7bit non-ascii
// string and aDefaultCharset is a 7bit non-ascii charset.
bool skipCheck = (c == 0x1B || c == '~') &&
IS_7BIT_NON_ASCII_CHARSET(aDefaultCharset);
// If not UTF-8, treat as default charset
nsCOMPtr<nsIUTF8ConverterService>
cvtUTF8(do_GetService(NS_UTF8CONVERTERSERVICE_CONTRACTID));
nsCAutoString utf8Text;
if (cvtUTF8 &&
NS_SUCCEEDED(
cvtUTF8->ConvertStringToUTF8(Substring(aInput, aInput + aLen),
aDefaultCharset, skipCheck, utf8Text))) {
aOutput.Append(utf8Text);
} else { // replace each octet with Unicode replacement char in UTF-8.
for (PRUint32 i = 0; i < aLen; i++) {
c = PRUint8(*aInput++);
if (c & 0x80)
aOutput.Append(REPLACEMENT_CHAR);
else
aOutput.Append(char(c));
}
}
}
static const char especials[] = "()<>@,;:\\\"/[]?.=";
// |decode_mime_part2_str| taken from comi18n.c
// Decode RFC2047-encoded words in the input and convert the result to UTF-8.
// If aOverrideCharset is true, charset in RFC2047-encoded words is
// ignored and aDefaultCharset is assumed, instead. aDefaultCharset
// is also used to convert raw octets (without RFC 2047 encoding) to UTF-8.
//static
nsresult DecodeRFC2047Str(const char *aHeader, const char *aDefaultCharset,
bool aOverrideCharset, nsACString &aResult)
{
const char *p, *q, *r;
char *decodedText;
const char *begin; // tracking pointer for where we are in the input buffer
PRInt32 isLastEncodedWord = 0;
const char *charsetStart, *charsetEnd;
char charset[80];
// initialize charset name to an empty string
charset[0] = '\0';
begin = aHeader;
// To avoid buffer realloc, if possible, set capacity in advance. No
// matter what, more than 3x expansion can never happen for all charsets
// supported by Mozilla. SCSU/BCSU with the sliding window set to a
// non-BMP block may be exceptions, but Mozilla does not support them.
// Neither any known mail/news program use them. Even if there's, we're
// safe because we don't use a raw *char any more.
aResult.SetCapacity(3 * strlen(aHeader));
while ((p = PL_strstr(begin, "=?")) != 0) {
if (isLastEncodedWord) {
// See if it's all whitespace.
for (q = begin; q < p; ++q) {
if (!PL_strchr(" \t\r\n", *q)) break;
}
}
if (!isLastEncodedWord || q < p) {
// copy the part before the encoded-word
CopyRawHeader(begin, p - begin, aDefaultCharset, aResult);
begin = p;
}
p += 2;
// Get charset info
charsetStart = p;
charsetEnd = 0;
for (q = p; *q != '?'; q++) {
if (*q <= ' ' || PL_strchr(especials, *q)) {
goto badsyntax;
}
// RFC 2231 section 5
if (!charsetEnd && *q == '*') {
charsetEnd = q;
}
}
if (!charsetEnd) {
charsetEnd = q;
}
// Check for too-long charset name
if (PRUint32(charsetEnd - charsetStart) >= sizeof(charset))
goto badsyntax;
memcpy(charset, charsetStart, charsetEnd - charsetStart);
charset[charsetEnd - charsetStart] = 0;
q++;
if (*q != 'Q' && *q != 'q' && *q != 'B' && *q != 'b')
goto badsyntax;
if (q[1] != '?')
goto badsyntax;
r = q;
for (r = q + 2; *r != '?'; r++) {
if (*r < ' ') goto badsyntax;
}
if (r[1] != '=')
goto badsyntax;
else if (r == q + 2) {
// it's empty, skip
begin = r + 2;
isLastEncodedWord = 1;
continue;
}
if(*q == 'Q' || *q == 'q')
decodedText = DecodeQ(q + 2, r - (q + 2));
else {
// bug 227290. ignore an extraneous '=' at the end.
// (# of characters in B-encoded part has to be a multiple of 4)
PRInt32 n = r - (q + 2);
n -= (n % 4 == 1 && !PL_strncmp(r - 3, "===", 3)) ? 1 : 0;
decodedText = PL_Base64Decode(q + 2, n, nsnull);
}
if (decodedText == nsnull)
goto badsyntax;
// Override charset if requested. Never override labeled UTF-8.
// Use default charset instead of UNKNOWN-8BIT
if ((aOverrideCharset && 0 != nsCRT::strcasecmp(charset, "UTF-8")) ||
(aDefaultCharset && 0 == nsCRT::strcasecmp(charset, "UNKNOWN-8BIT"))) {
PL_strncpy(charset, aDefaultCharset, sizeof(charset) - 1);
charset[sizeof(charset) - 1] = '\0';
}
{
nsCOMPtr<nsIUTF8ConverterService>
cvtUTF8(do_GetService(NS_UTF8CONVERTERSERVICE_CONTRACTID));
nsCAutoString utf8Text;
// skip ASCIIness/UTF8ness test if aCharset is 7bit non-ascii charset.
if (cvtUTF8 &&
NS_SUCCEEDED(
cvtUTF8->ConvertStringToUTF8(nsDependentCString(decodedText),
charset, IS_7BIT_NON_ASCII_CHARSET(charset), utf8Text))) {
aResult.Append(utf8Text);
} else {
aResult.Append(REPLACEMENT_CHAR);
}
}
PR_Free(decodedText);
begin = r + 2;
isLastEncodedWord = 1;
continue;
badsyntax:
// copy the part before the encoded-word
aResult.Append(begin, p - begin);
begin = p;
isLastEncodedWord = 0;
}
// put the tail back
CopyRawHeader(begin, strlen(begin), aDefaultCharset, aResult);
nsCAutoString tempStr(aResult);
tempStr.ReplaceChar('\t', ' ');
aResult = tempStr;
return NS_OK;
}