File indexing completed on 2022-10-04 16:37:42

 /*
   kmime_codecs.cpp
 
   KMime, the KDE Internet mail/usenet news message library.
   SPDX-FileCopyrightText: 2001 the KMime authors.
   See file AUTHORS for details
 
   SPDX-License-Identifier: LGPL-2.0-or-later
 */
 
 #include "kmime_codecs.h"
 #include "kmime_debug.h"
 #include <KCharsets>
 
 #include <QTextCodec>
 
 namespace KMime {
 
 static const char reservedCharacters[] = "\"()<>@,.;:\\[]=";
 
 QByteArray encodeRFC2047String(const QString &src, const QByteArray &charset,
                                bool addressHeader, bool allow8BitHeaders)
 {
     QByteArray result;
     int start = 0;
     int end = 0;
     bool nonAscii = false;
     bool ok = true;
     bool useQEncoding = false;
 
     // fromLatin1() is safe here, codecForName() uses toLatin1() internally
     const QTextCodec *codec = KCharsets::charsets()->codecForName(QString::fromLatin1(charset), ok);
 
     QByteArray usedCS;
     if (!ok) {
         //no codec available => try local8Bit and hope the best ;-)
         usedCS = QTextCodec::codecForLocale()->name();
         codec = KCharsets::charsets()->codecForName(QString::fromLatin1(usedCS), ok);
     } else {
         Q_ASSERT(codec);
         if (charset.isEmpty()) {
             usedCS = codec->name();
         } else {
             usedCS = charset;
         }
     }
 
     QTextCodec::ConverterState converterState(QTextCodec::IgnoreHeader);
     QByteArray encoded8Bit = codec->fromUnicode(src.constData(), src.length(), &converterState);
     if (converterState.invalidChars > 0) {
         usedCS = "utf-8";
         codec = QTextCodec::codecForName(usedCS);
         encoded8Bit = codec->fromUnicode(src);
     }
 
     if (usedCS.contains("8859-")) {     // use "B"-Encoding for non iso-8859-x charsets
         useQEncoding = true;
     }
 
     if (allow8BitHeaders) {
         return encoded8Bit;
     }
 
     int encoded8BitLength = encoded8Bit.length();
     for (int i = 0; i < encoded8BitLength; i++) {
         if (encoded8Bit[i] == ' ') {   // encoding starts at word boundaries
             start = i + 1;
         }
 
         // encode escape character, for japanese encodings...
         if (((signed char)encoded8Bit[i] < 0) || (encoded8Bit[i] == '\033') ||
                 (addressHeader && (strchr("\"()<>@,.;:\\[]=", encoded8Bit[i]) != nullptr))) {
             end = start;   // non us-ascii char found, now we determine where to stop encoding
             nonAscii = true;
             break;
         }
     }
 
     if (nonAscii) {
         while ((end < encoded8Bit.length()) && (encoded8Bit[end] != ' ')) {
             // we encode complete words
             end++;
         }
 
         for (int x = end; x < encoded8Bit.length(); x++) {
             if (((signed char)encoded8Bit[x] < 0) || (encoded8Bit[x] == '\033') ||
                     (addressHeader && (strchr(reservedCharacters, encoded8Bit[x]) != nullptr))) {
                 end = x;     // we found another non-ascii word
 
                 while ((end < encoded8Bit.length()) && (encoded8Bit[end] != ' ')) {
                     // we encode complete words
                     end++;
                 }
             }
         }
 
         result = encoded8Bit.left(start) + "=?" + usedCS;
 
         if (useQEncoding) {
             result += "?Q?";
 
             char c;
             char hexcode; // "Q"-encoding implementation described in RFC 2047
             for (int i = start; i < end; i++) {
                 c = encoded8Bit[i];
                 if (c == ' ') {   // make the result readable with not MIME-capable readers
                     result += '_';
                 } else {
                     if (((c >= 'a') && (c <= 'z')) ||        // paranoid mode, encode *all* special chars to avoid problems
                             ((c >= 'A') && (c <= 'Z')) ||        // with "From" & "To" headers
                             ((c >= '0') && (c <= '9'))) {
                         result += c;
                     } else {
                         result += '=';                 // "stolen" from KMail ;-)
                         hexcode = ((c & 0xF0) >> 4) + 48;
                         if (hexcode >= 58) {
                             hexcode += 7;
                         }
                         result += hexcode;
                         hexcode = (c & 0x0F) + 48;
                         if (hexcode >= 58) {
                             hexcode += 7;
                         }
                         result += hexcode;
                     }
                 }
             }
         } else {
             result += "?B?" + encoded8Bit.mid(start, end - start).toBase64();
         }
 
         result += "?=";
         result += encoded8Bit.right(encoded8Bit.length() - end);
     } else {
         result = encoded8Bit;
     }
 
     return result;
 }
 
 QByteArray encodeRFC2047Sentence(const QString &src, const QByteArray &charset)
 {
     QByteArray result;
     const QChar *ch = src.constData();
     const int length = src.length();
     int pos = 0;
     int wordStart = 0;
 
     //qCDebug(KMIME_LOG) << "Input:" << src;
     // Loop over all characters of the string.
     // When encountering a split character, RFC-2047-encode the word before it, and add it to the result.
     while (pos < length) {
         //qCDebug(KMIME_LOG) << "Pos:" << pos << "Result:" << result << "Char:" << ch->toLatin1();
         const bool isAscii = ch->unicode() < 127;
         const bool isReserved = (strchr(reservedCharacters, ch->toLatin1()) != nullptr);
         if (isAscii && isReserved) {
             const int wordSize = pos - wordStart;
             if (wordSize > 0) {
                 const QString word = src.mid(wordStart, wordSize);
                 result += encodeRFC2047String(word, charset);
             }
 
             result += ch->toLatin1();
             wordStart = pos + 1;
         }
         ch++;
         pos++;
     }
 
     // Encode the last word
     const int wordSize = pos - wordStart;
     if (wordSize > 0) {
         const QString word = src.mid(wordStart, pos - wordStart);
         result += encodeRFC2047String(word, charset);
     }
 
     return result;
 }
 
 //-----------------------------------------------------------------------------
 QByteArray encodeRFC2231String(const QString &str, const QByteArray &charset)
 {
     if (str.isEmpty()) {
       return {};
     }
 
     const QTextCodec *codec = KCharsets::charsets()->codecForName(QString::fromLatin1(charset));
     QByteArray latin;
     if (charset == "us-ascii") {
         latin = str.toLatin1();
     } else if (codec) {
         latin = codec->fromUnicode(str);
     } else {
         latin = str.toLocal8Bit();
     }
 
     char *l;
     for (l = latin.data(); *l; ++l) {
         if (((*l & 0xE0) == 0) || (*l & 0x80)) {
             // *l is control character or 8-bit char
             break;
         }
     }
     if (!*l) {
         return latin;
     }
 
     QByteArray result = charset + "''";
     for (l = latin.data(); *l; ++l) {
         bool needsQuoting = (*l & 0x80) || (*l == '%');
         if (!needsQuoting) {
             const QByteArray especials = "()<>@,;:\"/[]?.= \033";
             int len = especials.length();
             for (int i = 0; i < len; i++) {
                 if (*l == especials[i]) {
                     needsQuoting = true;
                     break;
                 }
             }
         }
         if (needsQuoting) {
             result += '%';
             unsigned char hexcode;
             hexcode = ((*l & 0xF0) >> 4) + 48;
             if (hexcode >= 58) {
                 hexcode += 7;
             }
             result += hexcode;
             hexcode = (*l & 0x0F) + 48;
             if (hexcode >= 58) {
                 hexcode += 7;
             }
             result += hexcode;
         } else {
             result += *l;
         }
     }
     return result;
 }
 
 //-----------------------------------------------------------------------------
 QString decodeRFC2231String(const QByteArray &str, QByteArray &usedCS, const QByteArray &defaultCS,
                             bool forceCS)
 {
     int p = str.indexOf('\'');
     if (p < 0) {
         return KCharsets::charsets()->codecForName(QString::fromLatin1(defaultCS))->toUnicode(str);
     }
 
     QByteArray charset = str.left(p);
 
     QByteArray st = str.mid(str.lastIndexOf('\'') + 1);
 
     char ch;
     char ch2;
     p = 0;
     while (p < st.length()) {
         if (st.at(p) == 37) {
             // Only try to decode the percent-encoded character if the percent sign
             // is really followed by two other characters, see testcase at bug 163024
             if (p + 2 < st.length()) {
                 ch = st.at(p + 1) - 48;
                 if (ch > 16) {
                     ch -= 7;
                 }
                 ch2 = st.at(p + 2) - 48;
                 if (ch2 > 16) {
                     ch2 -= 7;
                 }
                 st[p] = ch * 16 + ch2;
                 st.remove(p + 1, 2);
             }
         }
         p++;
     }
     qCDebug(KMIME_LOG) << "Got pre-decoded:" << st;
     const QTextCodec *charsetcodec = KCharsets::charsets()->codecForName(QString::fromLatin1(charset));
     if (!charsetcodec || forceCS) {
         charsetcodec = KCharsets::charsets()->codecForName(QString::fromLatin1(defaultCS));
     }
 
     usedCS = charsetcodec->name();
     return charsetcodec->toUnicode(st);
 }
 
 }