File indexing completed on 2024-09-15 04:36:25

 /*
     SPDX-FileCopyrightText: 2006-2007 Volker Krause <vkrause@kde.org>
 
     SPDX-License-Identifier: LGPL-2.0-or-later
 */
 
 #include "imapparser_p.h"
 
 #include <QDateTime>
 #include <QTimeZone>
 
 #include <ctype.h>
 
 using namespace Akonadi;
 
 class Akonadi::ImapParserPrivate
 {
 public:
     QByteArray tagBuffer;
     QByteArray dataBuffer;
     int parenthesesCount;
     qint64 literalSize;
     bool continuation;
 
     // returns true if readBuffer contains a literal start and sets
     // parser state accordingly
     bool checkLiteralStart(const QByteArray &readBuffer, int pos = 0)
     {
         if (readBuffer.trimmed().endsWith('}')) {
             const int begin = readBuffer.lastIndexOf('{');
             const int end = readBuffer.lastIndexOf('}');
 
             // new literal in previous literal data block
             if (begin < pos) {
                 return false;
             }
 
             // TODO error handling
             literalSize = readBuffer.mid(begin + 1, end - begin - 1).toLongLong();
 
             // empty literal
             if (literalSize == 0) {
                 return false;
             }
 
             continuation = true;
             dataBuffer.reserve(dataBuffer.size() + static_cast<int>(literalSize) + 1);
             return true;
         }
         return false;
     }
 };
 
 namespace
 {
 template<typename T>
 int parseParenthesizedListHelper(const QByteArray &data, T &result, int start)
 {
     result.clear();
     if (start >= data.length()) {
         return data.length();
     }
 
     const int begin = data.indexOf('(', start);
     if (begin < 0) {
         return start;
     }
 
     result.reserve(16);
 
     int count = 0;
     int sublistBegin = start;
     bool insideQuote = false;
     for (int i = begin + 1; i < data.length(); ++i) {
         const char currentChar = data[i];
         if (currentChar == '(' && !insideQuote) {
             ++count;
             if (count == 1) {
                 sublistBegin = i;
             }
 
             continue;
         }
 
         if (currentChar == ')' && !insideQuote) {
             if (count <= 0) {
                 return i + 1;
             }
 
             if (count == 1) {
                 result.append(data.mid(sublistBegin, i - sublistBegin + 1));
             }
 
             --count;
             continue;
         }
 
         if (currentChar == ' ' || currentChar == '\n' || currentChar == '\r') {
             continue;
         }
 
         if (count == 0) {
             QByteArray ba;
             const int consumed = ImapParser::parseString(data, ba, i);
             i = consumed - 1; // compensate for the for loop increment
             result.append(ba);
         } else if (count > 0) {
             if (currentChar == '"') {
                 insideQuote = !insideQuote;
             } else if (currentChar == '\\' && insideQuote) {
                 ++i;
                 continue;
             }
         }
     }
 
     return data.length();
 }
 
 } // namespace
 
 int ImapParser::parseParenthesizedList(const QByteArray &data, QVarLengthArray<QByteArray, 16> &result, int start)
 {
     return parseParenthesizedListHelper(data, result, start);
 }
 
 int ImapParser::parseParenthesizedList(const QByteArray &data, QList<QByteArray> &result, int start)
 {
     return parseParenthesizedListHelper(data, result, start);
 }
 
 int ImapParser::parseString(const QByteArray &data, QByteArray &result, int start)
 {
     int begin = stripLeadingSpaces(data, start);
     result.clear();
     if (begin >= data.length()) {
         return data.length();
     }
 
     // literal string
     // TODO: error handling
     if (data[begin] == '{') {
         int end = data.indexOf('}', begin);
         Q_ASSERT(end > begin);
         int size = data.mid(begin + 1, end - begin - 1).toInt();
 
         // strip CRLF
         begin = end + 1;
         if (begin < data.length() && data[begin] == '\r') {
             ++begin;
         }
         if (begin < data.length() && data[begin] == '\n') {
             ++begin;
         }
 
         end = begin + size;
         result = data.mid(begin, end - begin);
         return end;
     }
 
     // quoted string
     return parseQuotedString(data, result, begin);
 }
 
 int ImapParser::parseQuotedString(const QByteArray &data, QByteArray &result, int start)
 {
     int begin = stripLeadingSpaces(data, start);
     int end = begin;
     result.clear();
     if (begin >= data.length()) {
         return data.length();
     }
 
     bool foundSlash = false;
     // quoted string
     if (data[begin] == '"') {
         ++begin;
         result.reserve(qMin(32, data.size() - begin));
         for (int i = begin; i < data.length(); ++i) {
             const char ch = data.at(i);
             if (foundSlash) {
                 foundSlash = false;
                 if (ch == 'r') {
                     result += '\r';
                 } else if (ch == 'n') {
                     result += '\n';
                 } else if (ch == '\\') {
                     result += '\\';
                 } else if (ch == '\"') {
                     result += '\"';
                 } else {
                     // TODO: this is actually an error
                     result += ch;
                 }
                 continue;
             }
             if (ch == '\\') {
                 foundSlash = true;
                 continue;
             }
             if (ch == '"') {
                 end = i + 1; // skip the '"'
                 break;
             }
             result += ch;
         }
     } else {
         // unquoted string
         bool reachedInputEnd = true;
         for (int i = begin; i < data.length(); ++i) {
             const char ch = data.at(i);
             if (ch == ' ' || ch == '(' || ch == ')' || ch == '\n' || ch == '\r') {
                 end = i;
                 reachedInputEnd = false;
                 break;
             }
             if (ch == '\\') {
                 foundSlash = true;
             }
         }
         if (reachedInputEnd) {
             end = data.length();
         }
         result = data.mid(begin, end - begin);
 
         // transform unquoted NIL
         if (result == "NIL") {
             result.clear();
         }
 
         // strip quotes
         if (foundSlash) {
             while (result.contains("\\\"")) {
                 result.replace("\\\"", "\"");
             }
             while (result.contains("\\\\")) {
                 result.replace("\\\\", "\\");
             }
         }
     }
 
     return end;
 }
 
 int ImapParser::stripLeadingSpaces(const QByteArray &data, int start)
 {
     for (int i = start; i < data.length(); ++i) {
         if (data[i] != ' ') {
             return i;
         }
     }
 
     return data.length();
 }
 
 int ImapParser::parenthesesBalance(const QByteArray &data, int start)
 {
     int count = 0;
     bool insideQuote = false;
     for (int i = start; i < data.length(); ++i) {
         const char ch = data[i];
         if (ch == '"') {
             insideQuote = !insideQuote;
             continue;
         }
         if (ch == '\\' && insideQuote) {
             ++i;
             continue;
         }
         if (ch == '(' && !insideQuote) {
             ++count;
             continue;
         }
         if (ch == ')' && !insideQuote) {
             --count;
             continue;
         }
     }
     return count;
 }
 
 QByteArray ImapParser::join(const QList<QByteArray> &list, const QByteArray &separator)
 {
     // shortcuts for the easy cases
     if (list.isEmpty()) {
         return QByteArray();
     }
     if (list.size() == 1) {
         return list.first();
     }
 
     // avoid expensive realloc's by determining the size beforehand
     QList<QByteArray>::const_iterator it = list.constBegin();
     const QList<QByteArray>::const_iterator endIt = list.constEnd();
     int resultSize = (list.size() - 1) * separator.size();
     for (; it != endIt; ++it) {
         resultSize += (*it).size();
     }
 
     QByteArray result;
     result.reserve(resultSize);
     it = list.constBegin();
     result += (*it);
     ++it;
     for (; it != endIt; ++it) {
         result += separator;
         result += (*it);
     }
 
     return result;
 }
 
 QByteArray ImapParser::join(const QSet<QByteArray> &set, const QByteArray &separator)
 {
     const QList<QByteArray> list(set.begin(), set.end());
 
     return ImapParser::join(list, separator);
 }
 
 int ImapParser::parseString(const QByteArray &data, QString &result, int start)
 {
     QByteArray tmp;
     const int end = parseString(data, tmp, start);
     result = QString::fromUtf8(tmp);
     return end;
 }
 
 int ImapParser::parseNumber(const QByteArray &data, qint64 &result, bool *ok, int start)
 {
     if (ok) {
         *ok = false;
     }
 
     int pos = stripLeadingSpaces(data, start);
     if (pos >= data.length()) {
         return data.length();
     }
 
     int begin = pos;
     for (; pos < data.length(); ++pos) {
         if (!isdigit(data.at(pos))) {
             break;
         }
     }
 
     const QByteArray tmp = data.mid(begin, pos - begin);
     result = tmp.toLongLong(ok);
 
     return pos;
 }
 
 QByteArray ImapParser::quote(const QByteArray &data)
 {
     if (data.isEmpty()) {
         static const QByteArray empty("\"\"");
         return empty;
     }
 
     const int inputLength = data.length();
     int stuffToQuote = 0;
     for (int i = 0; i < inputLength; ++i) {
         const char ch = data.at(i);
         if (ch == '"' || ch == '\\' || ch == '\n' || ch == '\r') {
             ++stuffToQuote;
         }
     }
 
     QByteArray result;
     result.reserve(inputLength + stuffToQuote + 2);
     result += '"';
 
     // shortcut for the case that we don't need to quote anything at all
     if (stuffToQuote == 0) {
         result += data;
     } else {
         for (int i = 0; i < inputLength; ++i) {
             const char ch = data.at(i);
             if (ch == '\n') {
                 result += "\\n";
                 continue;
             }
 
             if (ch == '\r') {
                 result += "\\r";
                 continue;
             }
 
             if (ch == '"' || ch == '\\') {
                 result += '\\';
             }
 
             result += ch;
         }
     }
 
     result += '"';
     return result;
 }
 
 int ImapParser::parseSequenceSet(const QByteArray &data, ImapSet &result, int start)
 {
     int begin = stripLeadingSpaces(data, start);
     qint64 value = -1;
     qint64 lower = -1;
     qint64 upper = -1;
     for (int i = begin; i < data.length(); ++i) {
         if (data[i] == '*') {
             value = 0;
         } else if (data[i] == ':') {
             lower = value;
         } else if (isdigit(data[i])) {
             bool ok = false;
             i = parseNumber(data, value, &ok, i);
             Q_ASSERT(ok); // TODO handle error
             --i;
         } else {
             upper = value;
             if (lower < 0) {
                 lower = value;
             }
             result.add(ImapInterval(lower, upper));
             lower = -1;
             upper = -1; // NOLINT(clang-analyzer-deadcode.DeadStores) // false positive?
             value = -1;
             if (data[i] != ',') {
                 return i;
             }
         }
     }
     // take care of left-overs at input end
     upper = value;
     if (lower < 0) {
         lower = value;
     }
 
     if (lower >= 0 && upper >= 0) {
         result.add(ImapInterval(lower, upper));
     }
 
     return data.length();
 }
 
 int ImapParser::parseDateTime(const QByteArray &data, QDateTime &dateTime, int start)
 {
     // Syntax:
     // date-time      = DQUOTE date-day-fixed "-" date-month "-" date-year
     //                  SP time SP zone DQUOTE
     // date-day-fixed = (SP DIGIT) / 2DIGIT
     //                    ; Fixed-format version of date-day
     // date-month     = "Jan" / "Feb" / "Mar" / "Apr" / "May" / "Jun" /
     //                  "Jul" / "Aug" / "Sep" / "Oct" / "Nov" / "Dec"
     // date-year      = 4DIGIT
     // time           = 2DIGIT ":" 2DIGIT ":" 2DIGIT
     //                    ; Hours minutes seconds
     // zone           = ("+" / "-") 4DIGIT
     //                    ; Signed four-digit value of hhmm representing
     //                    ; hours and minutes east of Greenwich (that is,
     //                    ; the amount that the given time differs from
     //                    ; Universal Time).  Subtracting the timezone
     //                    ; from the given time will give the UT form.
     //                    ; The Universal Time zone is "+0000".
     // Example : "28-May-2006 01:03:35 +0200"
     // Position: 0123456789012345678901234567
     //                     1         2
 
     int pos = stripLeadingSpaces(data, start);
     if (data.length() <= pos) {
         return pos;
     }
 
     bool quoted = false;
     if (data[pos] == '"') {
         quoted = true;
         ++pos;
 
         if (data.length() <= pos + 26) {
             return start;
         }
     } else {
         if (data.length() < pos + 26) {
             return start;
         }
     }
 
     bool ok = true;
     const int day = (data[pos] == ' ' ? data[pos + 1] - '0' // single digit day
                                       : data.mid(pos, 2).toInt(&ok));
     if (!ok) {
         return start;
     }
 
     pos += 3;
     static const QByteArray shortMonthNames("janfebmaraprmayjunjulaugsepoctnovdec");
     int month = shortMonthNames.indexOf(data.mid(pos, 3).toLower());
     if (month == -1) {
         return start;
     }
 
     month = month / 3 + 1;
     pos += 4;
     const int year = data.mid(pos, 4).toInt(&ok);
     if (!ok) {
         return start;
     }
 
     pos += 5;
     const int hours = data.mid(pos, 2).toInt(&ok);
     if (!ok) {
         return start;
     }
 
     pos += 3;
     const int minutes = data.mid(pos, 2).toInt(&ok);
     if (!ok) {
         return start;
     }
 
     pos += 3;
     const int seconds = data.mid(pos, 2).toInt(&ok);
     if (!ok) {
         return start;
     }
 
     pos += 4;
     const int tzhh = data.mid(pos, 2).toInt(&ok);
     if (!ok) {
         return start;
     }
 
     pos += 2;
     const int tzmm = data.mid(pos, 2).toInt(&ok);
     if (!ok) {
         return start;
     }
 
     int tzsecs = tzhh * 60 * 60 + tzmm * 60;
     if (data[pos - 3] == '-') {
         tzsecs = -tzsecs;
     }
 
     const QDate date(year, month, day);
     const QTime time(hours, minutes, seconds);
     dateTime = QDateTime(date, time, QTimeZone::UTC);
     if (!dateTime.isValid()) {
         return start;
     }
 
     dateTime = dateTime.addSecs(-tzsecs);
 
     pos += 2;
     if (data.length() <= pos || !quoted) {
         return pos;
     }
 
     if (data[pos] == '"') {
         ++pos;
     }
 
     return pos;
 }
 
 void ImapParser::splitVersionedKey(const QByteArray &data, QByteArray &key, int &version)
 {
     const int startPos = data.indexOf('[');
     const int endPos = data.indexOf(']');
     if (startPos != -1 && endPos != -1) {
         if (endPos > startPos) {
             bool ok = false;
 
             version = data.mid(startPos + 1, endPos - startPos - 1).toInt(&ok);
             if (!ok) {
                 version = 0;
             }
 
             key = data.left(startPos);
         }
     } else {
         key = data;
         version = 0;
     }
 }
 
 ImapParser::ImapParser()
     : d(new ImapParserPrivate)
 {
     reset();
 }
 
 ImapParser::~ImapParser() = default;
 
 bool ImapParser::parseNextLine(const QByteArray &readBuffer)
 {
     d->continuation = false;
 
     // first line, get the tag
     if (d->tagBuffer.isEmpty()) {
         const int startOfData = ImapParser::parseString(readBuffer, d->tagBuffer);
         if (startOfData < readBuffer.length() && startOfData >= 0) {
             d->dataBuffer = readBuffer.mid(startOfData + 1);
         }
 
     } else {
         d->dataBuffer += readBuffer;
     }
 
     // literal read in progress
     if (d->literalSize > 0) {
         d->literalSize -= readBuffer.size();
 
         // still not everything read
         if (d->literalSize > 0) {
             return false;
         }
 
         // check the remaining (non-literal) part for parentheses
         if (d->literalSize < 0) {
             // the following looks strange but works since literalSize can be negative here
             d->parenthesesCount += ImapParser::parenthesesBalance(readBuffer, readBuffer.length() + static_cast<int>(d->literalSize));
 
             // check if another literal read was started
             if (d->checkLiteralStart(readBuffer, readBuffer.length() + static_cast<int>(d->literalSize))) {
                 return false;
             }
         }
 
         // literal string finished but still open parentheses
         if (d->parenthesesCount > 0) {
             return false;
         }
 
     } else {
         // open parentheses
         d->parenthesesCount += ImapParser::parenthesesBalance(readBuffer);
 
         // start new literal read
         if (d->checkLiteralStart(readBuffer)) {
             return false;
         }
 
         // still open parentheses
         if (d->parenthesesCount > 0) {
             return false;
         }
 
         // just a normal response, fall through
     }
 
     return true;
 }
 
 void ImapParser::parseBlock(const QByteArray &data)
 {
     Q_ASSERT(d->literalSize >= data.size());
     d->literalSize -= data.size();
     d->dataBuffer += data;
 }
 
 QByteArray ImapParser::tag() const
 {
     return d->tagBuffer;
 }
 
 QByteArray ImapParser::data() const
 {
     return d->dataBuffer;
 }
 
 void ImapParser::reset()
 {
     d->dataBuffer.clear();
     d->tagBuffer.clear();
     d->parenthesesCount = 0;
     d->literalSize = 0;
     d->continuation = false;
 }
 
 bool ImapParser::continuationStarted() const
 {
     return d->continuation;
 }
 
 qint64 ImapParser::continuationSize() const
 {
     return d->literalSize;
 }