File indexing completed on 2024-12-08 04:20:08

 /*
  * Copyright (C) 2003-2005  Justin Karneges <justin@affinix.com>
  * Copyright (C) 2004,2005  Brad Hards <bradh@frogmouth.net>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with this library; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  * 02110-1301  USA
  *
  */
 
 #include "qca_textfilter.h"
 
 namespace QCA {
 
 //----------------------------------------------------------------------------
 // TextFilter
 //----------------------------------------------------------------------------
 TextFilter::TextFilter(Direction dir)
 {
     setup(dir);
 }
 
 void TextFilter::setup(Direction dir)
 {
     _dir = dir;
 }
 
 Direction TextFilter::direction() const
 {
     return _dir;
 }
 
 MemoryRegion TextFilter::encode(const MemoryRegion &a)
 {
     setup(Encode);
     return process(a);
 }
 
 MemoryRegion TextFilter::decode(const MemoryRegion &a)
 {
     setup(Decode);
     return process(a);
 }
 
 QString TextFilter::arrayToString(const MemoryRegion &a)
 {
     return QString::fromLatin1(encode(a).toByteArray());
 }
 
 MemoryRegion TextFilter::stringToArray(const QString &s)
 {
     if (s.isEmpty())
         return MemoryRegion();
     return decode(s.toLatin1());
 }
 
 QString TextFilter::encodeString(const QString &s)
 {
     return arrayToString(s.toUtf8());
 }
 
 QString TextFilter::decodeString(const QString &s)
 {
     return QString::fromUtf8(stringToArray(s).toByteArray());
 }
 
 //----------------------------------------------------------------------------
 // Hex
 //----------------------------------------------------------------------------
 static int enhex(uchar c)
 {
     if (c < 10)
         return c + '0';
     else if (c < 16)
         return c - 10 + 'a';
     else
         return -1;
 }
 
 static int dehex(char c)
 {
     if (c >= 'a' && c <= 'f')
         return c - 'a' + 10;
     else if (c >= 'A' && c <= 'F')
         return c - 'A' + 10;
     else if (c >= '0' && c <= '9')
         return c - '0';
     else
         return -1;
 }
 
 Hex::Hex(Direction dir)
     : TextFilter(dir)
 {
     clear();
 }
 
 void Hex::clear()
 {
     partial = false;
     _ok     = true;
 }
 
 MemoryRegion Hex::update(const MemoryRegion &m)
 {
     const QByteArray a = m.toByteArray();
     if (_dir == Encode) {
         QByteArray out(a.size() * 2, 0);
         int        at = 0;
         int        c;
         for (const char ac : a) {
             uchar lo = (uchar)ac & 0x0f;
             uchar hi = (uchar)ac >> 4;
             c        = enhex(hi);
             if (c == -1) {
                 _ok = false;
                 break;
             }
             out[at++] = (char)c;
             c         = enhex(lo);
             if (c == -1) {
                 _ok = false;
                 break;
             }
             out[at++] = (char)c;
         }
         if (!_ok)
             return MemoryRegion();
 
         return out;
     } else {
         uchar lo   = 0;
         uchar hi   = 0;
         bool  flag = false;
         if (partial) {
             hi   = val;
             flag = true;
         }
 
         QByteArray out(a.size() / 2, 0);
         int        at = 0;
         int        c;
         for (const char ac : a) {
             c = dehex(ac);
             if (c == -1) {
                 _ok = false;
                 break;
             }
             if (flag) {
                 lo         = (uchar)c;
                 uchar full = ((hi & 0x0f) << 4) + (lo & 0x0f);
                 out[at++]  = full;
                 flag       = false;
             } else {
                 hi   = (uchar)c;
                 flag = true;
             }
         }
         if (!_ok)
             return MemoryRegion();
 
         if (flag) {
             val     = hi;
             partial = true;
         }
         return out;
     }
 }
 
 MemoryRegion Hex::final()
 {
     if (partial)
         _ok = false;
     return MemoryRegion();
 }
 
 bool Hex::ok() const
 {
     return _ok;
 }
 
 //----------------------------------------------------------------------------
 // Base64
 //----------------------------------------------------------------------------
 Base64::Base64(Direction dir)
     : TextFilter(dir)
 {
     _lb_enabled = false;
     _lb_column  = 76;
 }
 
 void Base64::clear()
 {
     partial.resize(0);
     _ok = true;
     col = 0;
 }
 
 bool Base64::lineBreaksEnabled() const
 {
     return _lb_enabled;
 }
 
 int Base64::lineBreaksColumn() const
 {
     return _lb_column;
 }
 
 void Base64::setLineBreaksEnabled(bool b)
 {
     _lb_enabled = b;
 }
 
 void Base64::setLineBreaksColumn(int column)
 {
     if (column > 0)
         _lb_column = column;
     else
         _lb_column = 76;
 }
 
 static QByteArray b64encode(const QByteArray &s)
 {
     int               i;
     const int         len = s.size();
     static const char tbl[] =
         "ABCDEFGH"
         "IJKLMNOP"
         "QRSTUVWX"
         "YZabcdef"
         "ghijklmn"
         "opqrstuv"
         "wxyz0123"
         "456789+/"
         "=";
     int a, b, c;
 
     QByteArray p((len + 2) / 3 * 4, 0);
     int        at = 0;
     for (i = 0; i < len; i += 3) {
         a = ((unsigned char)s[i] & 3) << 4;
         if (i + 1 < len) {
             a += (unsigned char)s[i + 1] >> 4;
             b = ((unsigned char)s[i + 1] & 0xf) << 2;
             if (i + 2 < len) {
                 b += (unsigned char)s[i + 2] >> 6;
                 c = (unsigned char)s[i + 2] & 0x3f;
             } else
                 c = 64;
         } else
             b = c = 64;
 
         p[at++] = tbl[(unsigned char)s[i] >> 2];
         p[at++] = tbl[a];
         p[at++] = tbl[b];
         p[at++] = tbl[c];
     }
     return p;
 }
 
 static QByteArray b64decode(const QByteArray &s, bool *ok)
 {
     // -1 specifies invalid
     // 64 specifies eof
     // everything else specifies data
 
     static const signed char tbl[] = {
         -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
         -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63, 52, 53, 54, 55,
         56, 57, 58, 59, 60, 61, -1, -1, -1, 64, -1, -1, -1, 0,  1,  2,  3,  4,  5,  6,  7,  8,  9,  10, 11, 12,
         13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1, -1, 26, 27, 28, 29, 30, 31, 32,
         33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1, -1, -1,
         -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
         -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
         -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
         -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
         -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
     };
 
     // return value
     QByteArray p;
     *ok = true;
 
     // this should be a multiple of 4
     const int len = s.size();
     if (len % 4) {
         *ok = false;
         return p;
     }
 
     p.resize(len / 4 * 3);
 
     int i;
     int at = 0;
 
     int a, b, c, d;
     c = d = 0;
 
     for (i = 0; i < len; i += 4) {
         a = tbl[(int)s[i]];
         b = tbl[(int)s[i + 1]];
         c = tbl[(int)s[i + 2]];
         d = tbl[(int)s[i + 3]];
         if ((a == 64 || b == 64) || (a < 0 || b < 0 || c < 0 || d < 0)) {
             p.resize(0);
             *ok = false;
             return p;
         }
         p[at++] = ((a & 0x3F) << 2) | ((b >> 4) & 0x03);
         p[at++] = ((b & 0x0F) << 4) | ((c >> 2) & 0x0F);
         p[at++] = ((c & 0x03) << 6) | ((d >> 0) & 0x3F);
     }
 
     if (c & 64)
         p.resize(at - 2);
     else if (d & 64)
         p.resize(at - 1);
 
     return p;
 }
 
 static int findLF(const QByteArray &in, int offset)
 {
     for (int n = offset; n < in.size(); ++n) {
         if (in[n] == '\n')
             return n;
     }
     return -1;
 }
 
 static QByteArray insert_linebreaks(const QByteArray &s, int *col, int lfAt)
 {
     QByteArray out = s;
 
     const int needed = (out.size() + *col) / lfAt; // how many newlines needed?
     if (needed > 0) {
         const int firstlen = lfAt - *col;                      // length of first chunk
         int       at       = firstlen + (lfAt * (needed - 1)); // position of last newline
         const int lastlen  = out.size() - at;                  // length of last chunk
 
         // printf("size=%d,needed=%d,firstlen=%d,at=%d,lastlen=%d\n", out.size(), needed, firstlen, at, lastlen);
 
         // make room
         out.resize(out.size() + needed);
 
         // move backwards
         for (int n = 0; n < needed; ++n) {
             char *p = out.data() + at;
             int   len;
             if (n == 0)
                 len = lastlen;
             else
                 len = lfAt;
             memmove(p + needed - n, p, len);
             p[needed - n - 1] = '\n';
             at -= lfAt;
         }
 
         *col = lastlen;
     } else
         *col += out.size();
 
     return out;
 }
 
 static QByteArray remove_linebreaks(const QByteArray &s)
 {
     QByteArray out = s;
 
     int removed = 0;
     int at      = findLF(out, 0);
     while (at != -1) {
         int next = findLF(out, at + 1);
         int len;
         if (next != -1)
             len = next - at;
         else
             len = out.size() - at;
 
         if (len > 1) {
             char *p = out.data() + at;
             memmove(p - removed, p + 1, len - 1);
         }
         ++removed;
         at = next;
     }
     out.resize(out.size() - removed);
 
     return out;
 }
 
 static void appendArray(QByteArray *a, const QByteArray &b)
 {
     a->append(b);
 }
 
 MemoryRegion Base64::update(const MemoryRegion &m)
 {
     QByteArray in;
     if (_dir == Decode && _lb_enabled)
         in = remove_linebreaks(m.toByteArray());
     else
         in = m.toByteArray();
 
     if (in.isEmpty())
         return MemoryRegion();
 
     int chunk;
     if (_dir == Encode)
         chunk = 3;
     else
         chunk = 4;
 
     const int size = partial.size() + in.size();
     if (size < chunk) {
         appendArray(&partial, in);
         return MemoryRegion();
     }
 
     int eat = size % chunk;
 
     // s = partial + a - eat
     QByteArray s(partial.size() + in.size() - eat, 0);
     memcpy(s.data(), partial.data(), partial.size());
     memcpy(s.data() + partial.size(), in.data(), in.size() - eat);
 
     partial.resize(eat);
     memcpy(partial.data(), in.data() + in.size() - eat, eat);
 
     if (_dir == Encode) {
         if (_lb_enabled)
             return insert_linebreaks(b64encode(s), &col, _lb_column);
         else
             return b64encode(s);
     } else {
         bool             ok;
         const QByteArray out = b64decode(s, &ok);
         if (!ok)
             _ok = false;
         return out;
     }
 }
 
 MemoryRegion Base64::final()
 {
     if (_dir == Encode) {
         if (_lb_enabled)
             return insert_linebreaks(b64encode(partial), &col, _lb_column);
         else
             return b64encode(partial);
     } else {
         bool             ok;
         const QByteArray out = b64decode(partial, &ok);
         if (!ok)
             _ok = false;
         return out;
     }
 }
 
 bool Base64::ok() const
 {
     return _ok;
 }
 
 }