File indexing completed on 2024-04-21 16:06:19

 /*
     kmime_parsers.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_parsers_p.h"
 
 #include <QRegularExpression>
 
 using namespace KMime::Parser;
 
 namespace KMime
 {
 namespace Parser
 {
 
 MultiPart::MultiPart(const QByteArray &src, const QByteArray &boundary)
     : m_src(src)
     , m_boundary(boundary)
 {
 }
 
 bool MultiPart::parse()
 {
     QByteArray b = "--" + m_boundary;
     QByteArray part;
     int pos1 = 0;
     int pos2 = 0;
     int blen = b.length();
 
     m_parts.clear();
 
     //find the first valid boundary
     while (true) {
         if ((pos1 = m_src.indexOf(b, pos1)) == -1 || pos1 == 0 ||
                 m_src[pos1 - 1] == '\n') { //valid boundary found or no boundary at all
             break;
         }
         pos1 += blen; //boundary found but not valid => skip it;
     }
 
     if (pos1 > -1) {
         pos1 += blen;
         if (m_src[pos1] == '-' && m_src[pos1 + 1] == '-') {
             // the only valid boundary is the end-boundary
             // this message is *really* broken
             pos1 = -1; //we give up
         } else if ((pos1 - blen) > 1) {     //preamble present
             m_preamble = m_src.left(pos1 - blen - 1);
         }
     }
 
     while (pos1 > -1 && pos2 > -1) {
 
         //skip the rest of the line for the first boundary - the message-part starts here
         if ((pos1 = m_src.indexOf('\n', pos1)) > -1) {
             //now search the next linebreak
             //now find the next valid boundary
             pos2 = ++pos1; //pos1 and pos2 point now to the beginning of the next line after the boundary
             while (true) {
                 if ((pos2 = m_src.indexOf(b, pos2)) == -1 ||
                         m_src[pos2 - 1] == '\n') { //valid boundary or no more boundaries found
                     break;
                 }
                 pos2 += blen; //boundary is invalid => skip it;
             }
 
             if (pos2 == -1) {   // no more boundaries found
                 part = m_src.mid(pos1, m_src.length() - pos1);   //take the rest of the string
                 m_parts.append(part);
                 pos1 = -1;
                 pos2 = -1; //break;
             } else {
                 part = m_src.mid(pos1, pos2 - pos1 - 1);   // pos2 - 1 (\n) is part of the boundary (see RFC 2046, section 5.1.1)
                 m_parts.append(part);
                 pos2 += blen; //pos2 points now to the first character after the boundary
                 if (m_src[pos2] == '-' && m_src[pos2 + 1] == '-') { //end-boundary
                     pos1 = pos2 + 2; //pos1 points now to the character directly after the end-boundary
 
                     if ((pos1 = m_src.indexOf('\n', pos1)) > -1) {       //skip the rest of this line
                         //everything after the end-boundary is considered as the epilouge
                         m_epilouge = m_src.mid(pos1 + 1, m_src.length() - pos1 - 1);
                     }
                     pos1 = -1;
                     pos2 = -1; //break
                 } else {
                     pos1 = pos2; //the search continues ...
                 }
             }
         }
     }
 
     return !m_parts.isEmpty();
 }
 
 //=============================================================================
 
 NonMimeParser::NonMimeParser(const QByteArray &src) :
     m_src(src), m_partNr(-1), m_totalNr(-1)
 {
 }
 
 NonMimeParser::~NonMimeParser() = default;
 
 /**
  * try to guess the mimetype from the file-extension
  */
 
 QByteArray NonMimeParser::guessMimeType(const QByteArray &fileName)
 {
     QByteArray tmp;
     QByteArray mimeType;
 
     if (!fileName.isEmpty()) {
         int pos = fileName.lastIndexOf('.');
         if (pos++ != -1) {
             tmp = fileName.mid(pos, fileName.length() - pos).toUpper();
             if (tmp == "JPG" || tmp == "JPEG") {
                 mimeType = QByteArrayLiteral("image/jpeg");
             } else if (tmp == "GIF") {
                 mimeType = QByteArrayLiteral("image/gif");
             } else if (tmp == "PNG") {
                 mimeType = QByteArrayLiteral("image/png");
             } else if (tmp == "TIFF" || tmp == "TIF") {
                 mimeType = QByteArrayLiteral("image/tiff");
             } else if (tmp == "XPM") {
                 mimeType = QByteArrayLiteral("image/x-xpixmap");
             } else if (tmp == "XBM") {
                 mimeType = QByteArrayLiteral("image/x-xbitmap");
             } else if (tmp == "BMP") {
                 mimeType = QByteArrayLiteral("image/bmp");
             } else if (tmp == "TXT" ||
                        tmp == "ASC" ||
                        tmp == "H" ||
                        tmp == "C" ||
                        tmp == "CC" ||
                        tmp == "CPP") {
                 mimeType = QByteArrayLiteral("text/plain");
             } else if (tmp == "HTML" || tmp == "HTM") {
                 mimeType = QByteArrayLiteral("text/html");
             } else {
                 mimeType = QByteArrayLiteral("application/octet-stream");
             }
         } else {
             mimeType = QByteArrayLiteral("application/octet-stream");
         }
     } else {
         mimeType = QByteArrayLiteral("application/octet-stream");
     }
 
     return mimeType;
 }
 
 //==============================================================================
 
 UUEncoded::UUEncoded(const QByteArray &src, const QByteArray &subject) :
     NonMimeParser(src), m_subject(subject)
 {}
 
 bool UUEncoded::parse()
 {
     int currentPos = 0;
     bool success = true;
     bool firstIteration = true;
 
     const auto srcStr = QString::fromLatin1(m_src);
     const QRegularExpression beginRegex(QStringLiteral("begin [0-9][0-9][0-9]"));
     const QRegularExpression subjectRegex(QStringLiteral("[0-9]+/[0-9]+"));
 
     while (success) {
         int beginPos = currentPos;
         int uuStart = currentPos;
         int endPos = 0;
         int lineCount = 0;
         int MCount = 0;
         int pos = 0;
         int len = 0;
         bool containsBegin = false;
         bool containsEnd = false;
         QByteArray tmp;
         QByteArray fileName;
 
         if ((beginPos = srcStr.indexOf(beginRegex, currentPos)) > -1 &&
                 (beginPos == 0 || m_src.at(beginPos - 1) == '\n')) {
             containsBegin = true;
             uuStart = m_src.indexOf('\n', beginPos);
             if (uuStart == -1) {  //no more line breaks found, we give up
                 success = false;
                 break;
             } else {
                 uuStart++; //points now at the beginning of the next line
             }
         } else {
             beginPos = currentPos;
         }
 
         if ((endPos = m_src.indexOf("\nend", (uuStart > 0) ? uuStart - 1 : 0)) == -1) {
             endPos = m_src.length(); //no end found
         } else {
             containsEnd = true;
         }
 
         if ((containsBegin && containsEnd) || firstIteration) {
 
             //printf("beginPos=%d , uuStart=%d , endPos=%d\n", beginPos, uuStart, endPos);
             //all lines in a uuencoded text start with 'M'
             for (int idx = uuStart; idx < endPos; idx++) {
                 if (m_src[idx] == '\n') {
                     lineCount++;
                     if (idx + 1 < endPos && m_src[idx + 1] == 'M') {
                         idx++;
                         MCount++;
                     }
                 }
             }
 
             //printf("lineCount=%d , MCount=%d\n", lineCount, MCount);
             if (MCount == 0 || (lineCount - MCount) > 10 ||
                     ((!containsBegin || !containsEnd) && (MCount < 15))) {
                 // harder check for split-articles
                 success = false;
                 break; //too many "non-M-Lines" found, we give up
             }
 
             if ((!containsBegin || !containsEnd) && !m_subject.isNull()) {
                 // message may be split up => parse subject
                 const auto match =
                     subjectRegex.match(QLatin1StringView(m_subject));
                 pos = match.capturedStart(0);
                 len = match.capturedLength(0);
                 if (pos != -1) {
                     tmp = m_subject.mid(pos, len);
                     pos = tmp.indexOf('/');
                     m_partNr = tmp.left(pos).toInt();
                     m_totalNr = tmp.right(tmp.length() - pos - 1).toInt();
                 } else {
                     success = false;
                     break; //no "part-numbers" found in the subject, we give up
                 }
             }
 
             //everything before "begin" is text
             if (beginPos > 0) {
                 m_text.append(m_src.mid(currentPos, beginPos - currentPos));
             }
 
             if (containsBegin) {
                 //everything between "begin ### " and the next LF is considered as the filename
                 fileName = m_src.mid(beginPos + 10, uuStart - beginPos - 11);
             } else {
                 fileName = "";
             }
             m_filenames.append(fileName);
             //everything between "begin" and "end" is uuencoded
             m_bins.append(m_src.mid(uuStart, endPos - uuStart + 1));
             m_mimeTypes.append(guessMimeType(fileName));
             firstIteration = false;
 
             int next = m_src.indexOf('\n', endPos + 1);
             if (next == -1) {   //no more line breaks found, we give up
                 success = false;
                 break;
             } else {
                 next++; //points now at the beginning of the next line
             }
             currentPos = next;
 
         } else {
             success = false;
         }
     }
 
     // append trailing text part of the article
     m_text.append(m_src.right(m_src.length() - currentPos));
 
     return ((!m_bins.isEmpty()) || isPartial());
 }
 
 //==============================================================================
 
 YENCEncoded::YENCEncoded(const QByteArray &src) :
     NonMimeParser(src)
 {
 }
 
 bool YENCEncoded::yencMeta(QByteArray &src, const QByteArray &name, int *value)
 {
     bool found = false;
     QByteArray sought = name + '=';
 
     int iPos = src.indexOf(sought);
     if (iPos > -1) {
         int pos1 = src.indexOf(' ', iPos);
         int pos2 = src.indexOf('\r', iPos);
         int pos3 = src.indexOf('\t', iPos);
         int pos4 = src.indexOf('\n', iPos);
         if (pos2 >= 0 && (pos1 < 0 || pos1 > pos2)) {
             pos1 = pos2;
         }
         if (pos3 >= 0 && (pos1 < 0 || pos1 > pos3)) {
             pos1 = pos3;
         }
         if (pos4 >= 0 && (pos1 < 0 || pos1 > pos4)) {
             pos1 = pos4;
         }
         iPos = src.lastIndexOf('=', pos1) + 1;
         if (iPos < pos1) {
             char c = src.at(iPos);
             if (c >= '0' && c <= '9') {
                 found = true;
                 *value = src.mid(iPos, pos1 - iPos).toInt();
             }
         }
     }
     return found;
 }
 
 bool YENCEncoded::parse()
 {
     int currentPos = 0;
     bool success = true;
     while (success) {
         int beginPos = currentPos;
         int yencStart = currentPos;
         bool containsPart = false;
         QByteArray fileName;
 
         if ((beginPos = m_src.indexOf("=ybegin ", currentPos)) > -1 &&
                 (beginPos == 0 || m_src.at(beginPos - 1) == '\n')) {
             yencStart = m_src.indexOf('\n', beginPos);
             if (yencStart == -1) {   // no more line breaks found, give up
                 success = false;
                 break;
             } else {
                 yencStart++;
                 if (m_src.indexOf("=ypart", yencStart) == yencStart) {
                     containsPart = true;
                     yencStart = m_src.indexOf('\n', yencStart);
                     if (yencStart == -1) {
                         success = false;
                         break;
                     }
                     yencStart++;
                 }
             }
             // Try to identify yenc meta data
 
             // Filenames can contain any embedded chars until end of line
             QByteArray meta = m_src.mid(beginPos, yencStart - beginPos);
             int namePos = meta.indexOf("name=");
             if (namePos == -1) {
                 success = false;
                 break;
             }
             int eolPos = meta.indexOf('\r', namePos);
             if (eolPos == -1) {
                 eolPos = meta.indexOf('\n', namePos);
             }
             if (eolPos == -1) {
                 success = false;
                 break;
             }
             fileName = meta.mid(namePos + 5, eolPos - (namePos + 5));
 
             // Other metadata is integer
             int yencLine;
             if (!yencMeta(meta, "line", &yencLine)) {
                 success = false;
                 break;
             }
             int yencSize;
             if (!yencMeta(meta, "size", &yencSize)) {
                 success = false;
                 break;
             }
 
             int partBegin;
             int partEnd;
             if (containsPart) {
                 if (!yencMeta(meta, "part", &m_partNr)) {
                     success = false;
                     break;
                 }
                 if (!yencMeta(meta, "begin", &partBegin) ||
                         !yencMeta(meta, "end", &partEnd)) {
                     success = false;
                     break;
                 }
                 if (!yencMeta(meta, "total", &m_totalNr)) {
                     m_totalNr = m_partNr + 1;
                 }
                 if (yencSize == partEnd - partBegin + 1) {
                     m_totalNr = 1;
                 } else {
                     yencSize = partEnd - partBegin + 1;
                 }
             }
 
             // We have a valid yenc header; now we extract the binary data
             int totalSize = 0;
             int pos = yencStart;
             int len = m_src.length();
             bool lineStart = true;
             int lineLength = 0;
             bool containsEnd = false;
             QByteArray binary;
             binary.resize(yencSize);
             while (pos < len) {
                 int ch = m_src.at(pos);
                 if (ch < 0) {
                     ch += 256;
                 }
                 if (ch == '\r') {
                     if (lineLength != yencLine && totalSize != yencSize) {
                         break;
                     }
                     pos++;
                 } else if (ch == '\n') {
                     lineStart = true;
                     lineLength = 0;
                     pos++;
                 } else {
                     if (ch == '=') {
                         if (pos + 1 < len) {
                             ch = m_src.at(pos + 1);
                             if (lineStart && ch == 'y') {
                                 containsEnd = true;
                                 break;
                             }
                             pos += 2;
                             ch -= 64 + 42;
                             if (ch < 0) {
                                 ch += 256;
                             }
                             if (totalSize >= yencSize) {
                                 break;
                             }
                             binary[totalSize++] = ch;
                             lineLength++;
                         } else {
                             break;
                         }
                     } else {
                         ch -= 42;
                         if (ch < 0) {
                             ch += 256;
                         }
                         if (totalSize >= yencSize) {
                             break;
                         }
                         binary[totalSize++] = ch;
                         lineLength++;
                         pos++;
                     }
                     lineStart = false;
                 }
             }
 
             if (!containsEnd) {
                 success = false;
                 break;
             }
             if (totalSize != yencSize) {
                 success = false;
                 break;
             }
 
             // pos now points to =yend; get end data
             eolPos = m_src.indexOf('\n', pos);
             if (eolPos == -1) {
                 success = false;
                 break;
             }
             meta = m_src.mid(pos, eolPos - pos);
             if (!yencMeta(meta, "size", &totalSize)) {
                 success = false;
                 break;
             }
             if (totalSize != yencSize) {
                 success = false;
                 break;
             }
 
             m_filenames.append(fileName);
             m_mimeTypes.append(guessMimeType(fileName));
             m_bins.append(binary);
 
             //everything before "begin" is text
             if (beginPos > 0) {
                 m_text.append(m_src.mid(currentPos, beginPos - currentPos));
             }
             currentPos = eolPos + 1;
 
         } else {
             success = false;
         }
     }
 
     // append trailing text part of the article
     m_text.append(m_src.right(m_src.length() - currentPos));
 
     return !m_bins.isEmpty();
 }
 
 } // namespace Parser
 
 } // namespace KMime