File indexing completed on 2025-07-13 04:50:07

 /*
   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_p.h"
 #include "kmime_debug.h"
 
 #include <QStringDecoder>
 #include <QStringEncoder>
 
 namespace KMime {
 
 static const char reservedCharacters[] = "\"()<>@,.;:\\[]=";
 
 QByteArray encodeRFC2047String(QStringView src, const QByteArray &charset,
                                bool addressHeader)
 {
     QByteArray result;
     int start = 0;
     int end = 0;
     bool nonAscii = false;
     bool useQEncoding = false;
 
     // fromLatin1() is safe here, codecForName() uses toLatin1() internally
     QStringEncoder codec(charset.constData());
 
     QByteArray usedCS;
     if (!codec.isValid()) {
         //no codec available => try local8Bit and hope the best ;-)
         codec = QStringEncoder(QStringEncoder::System);
         usedCS = codec.name();
     } else {
         if (charset.isEmpty()) {
             usedCS = codec.name();
         } else {
             usedCS = charset;
         }
     }
 
     QByteArray encoded8Bit = codec.encode(src);
     if (codec.hasError()) {
         usedCS = "utf-8";
         codec = QStringEncoder(usedCS.constData());
         encoded8Bit = codec.encode(src);
     }
 
     if (usedCS.contains("8859-")) {     // use "B"-Encoding for non iso-8859-x charsets
         useQEncoding = true;
     }
 
     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 hexcode; // "Q"-encoding implementation described in RFC 2047
             for (int i = start; i < end; i++) {
                 char 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(QStringView 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 auto 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 auto word = src.mid(wordStart, pos - wordStart);
         result += encodeRFC2047String(word, charset);
     }
 
     return result;
 }
 
 //-----------------------------------------------------------------------------
 QByteArray encodeRFC2231String(QStringView str, const QByteArray &charset)
 {
     if (str.isEmpty()) {
       return {};
     }
 
     QStringEncoder codec(charset.constData());
     QByteArray latin;
     if (charset == "us-ascii") {
         latin = str.toLatin1();
     } else if (codec.isValid()) {
         latin = codec.encode(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;
 }
 
 }