libdap++ Updated for version 3.8.2

escaping.cc

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00001 
00002 // -*- mode: c++; c-basic-offset:4 -*-
00003 
00004 // This file is part of libdap, A C++ implementation of the OPeNDAP Data
00005 // Access Protocol.
00006 
00007 // Copyright (c) 2002,2003 OPeNDAP, Inc.
00008 // Author: James Gallagher <jgallagher@opendap.org>
00009 //
00010 // This library is free software; you can redistribute it and/or
00011 // modify it under the terms of the GNU Lesser General Public
00012 // License as published by the Free Software Foundation; either
00013 // version 2.1 of the License, or (at your option) any later version.
00014 //
00015 // This library is distributed in the hope that it will be useful,
00016 // but WITHOUT ANY WARRANTY; without even the implied warranty of
00017 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00018 // Lesser General Public License for more details.
00019 //
00020 // You should have received a copy of the GNU Lesser General Public
00021 // License along with this library; if not, write to the Free Software
00022 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
00023 //
00024 // You can contact OPeNDAP, Inc. at PO Box 112, Saunderstown, RI. 02874-0112.
00025 
00026 // Copyright (c) 1996, California Institute of Technology.
00027 // ALL RIGHTS RESERVED.   U.S. Government Sponsorship acknowledged.
00028 //
00029 // Please read the full copyright notice in the file COPYRIGHT_URI
00030 // in this directory.
00031 //
00032 // Author: Todd Karakashian, NASA/Jet Propulsion Laboratory
00033 //         Todd.K.Karakashian@jpl.nasa.gov
00034 //
00035 // $RCSfile: escaping.cc,v $ - Miscellaneous routines for OPeNDAP HDF server
00036 //
00037 // These two routines are for escaping/unescaping strings that are identifiers
00038 // in DAP2
00039 // id2www() -- escape (using WWW hex codes) non-allowable characters in a
00040 // DAP2 identifier
00041 // www2id() -- given an WWW hexcode escaped identifier, restore it
00042 //
00043 // These two routines are for escaping/unescaping strings storing attribute
00044 // values.  They use traditional octal escapes (\nnn) because they are
00045 // intended to be viewed by a user
00046 // escattr() -- escape (using traditional octal backslash) non-allowable
00047 // characters in the value of a DAP2 attribute
00048 // unescattr() -- given an octally escaped string, restore it
00049 //
00050 // These are routines used by the above, not intended to be called directly:
00051 //
00052 // hexstring()
00053 // unhexstring()
00054 // octstring()
00055 // unoctstring()
00056 //
00057 // -Todd
00058 
00059 #include <ctype.h>
00060 
00061 #include <iomanip>
00062 #include <string>
00063 #include <sstream>
00064 
00065 #include "GNURegex.h"
00066 #include "Error.h"
00067 #include "InternalErr.h"
00068 //#define DODS_DEBUG
00069 #include "debug.h"
00070 
00071 using namespace std;
00072 
00073 namespace libdap {
00074 
00075 // The next four functions were originally defined static, but I removed that
00076 // to make testing them (see generalUtilTest.cc) easier to write. 5/7/2001
00077 // jhrg
00078 
00079 string
00080 hexstring(unsigned char val)
00081 {
00082     ostringstream buf;
00083     buf << hex << setw(2) << setfill('0') << static_cast<unsigned int>(val);
00084 
00085     return buf.str();
00086 }
00087 
00088 string
00089 unhexstring(string s)
00090 {
00091     int val;
00092     istringstream ss(s);
00093     ss >> hex >> val;
00094     char tmp_str[2];
00095     tmp_str[0] = static_cast<char>(val);
00096     tmp_str[1] = '\0';
00097     return string(tmp_str);
00098 }
00099 
00100 string
00101 octstring(unsigned char val)
00102 {
00103     ostringstream buf;
00104     buf << oct << setw(3) << setfill('0')
00105     << static_cast<unsigned int>(val);
00106 
00107     return buf.str();
00108 }
00109 
00110 string
00111 unoctstring(string s)
00112 {
00113     int val;
00114 
00115     istringstream ss(s);
00116     ss >> oct >> val;
00117 
00118     DBG(cerr << "unoctstring: " << val << endl);
00119 
00120     char tmp_str[2];
00121     tmp_str[0] = static_cast<char>(val);
00122     tmp_str[1] = '\0';
00123     return string(tmp_str);
00124 }
00125 
00150 string
00151 id2www(string in, const string &allowable)
00152 {
00153     string::size_type i = 0;
00154     DBG(cerr<<"Input string: [" << in << "]" << endl);
00155     while ((i = in.find_first_not_of(allowable, i)) != string::npos) {
00156         DBG(cerr<<"Found escapee: [" << in[i] << "]");
00157         in.replace(i, 1, "%" + hexstring(in[i]));
00158         DBGN(cerr<<" now the string is: " << in << endl);
00159         i += 3;//i++;
00160     }
00161 
00162     return in;
00163 }
00164 
00175 string
00176 id2www_ce(string in, const string &allowable)
00177 {
00178     return id2www(in, allowable);
00179 }
00180 
00213 string
00214 www2id(const string &in, const string &escape, const string &except)
00215 {
00216     string::size_type i = 0;
00217     string res = in;
00218     while ((i = res.find_first_of(escape, i)) != string::npos) {
00219         if (except.find(res.substr(i, 3)) != string::npos) {
00220             i += 3;
00221             continue;
00222         }
00223         res.replace(i, 3, unhexstring(res.substr(i + 1, 2)));
00224         ++i;
00225     }
00226 
00227     return res;
00228 }
00229 
00230 static string
00231 entity(char c)
00232 {
00233     switch (c) {
00234     case '>': return "&gt;";
00235     case '<': return "&lt;";
00236     case '&': return "&amp;";
00237     case '\'': return "&apos;";
00238     case '\"': return "&quot;";
00239     default:
00240         throw InternalErr(__FILE__, __LINE__, "Unrecognized character.");
00241     }
00242 }
00243 
00244 // Assumption: There are always exactly two octal digits in the input
00245 // and two hex digits in the result.
00246 string
00247 octal_to_hex(const string &octal_digits)
00248 {
00249     int val;
00250 
00251     istringstream ss(octal_digits);
00252     ss >> oct >> val;
00253 
00254     ostringstream ds;
00255     ds << hex << setw(2) << setfill('0') << val;
00256     return ds.str();
00257 }
00258 
00265 string
00266 id2xml(string in, const string &not_allowed)
00267 {
00268     string::size_type i = 0;
00269 
00270     while ((i = in.find_first_of(not_allowed, i)) != string::npos) {
00271         in.replace(i, 1, entity(in[i]));
00272         ++i;
00273     }
00274 #if 0
00275     // Removed the encoding of octal escapes. This function is used by
00276     // AttrTable to encode the stuff that is the value of the <value>
00277     // element in the DDX. The problem is that some of the values are not
00278     // valid UTF-8 and that makes a XML parser gag.; ticket 1512.
00279     // jhrg 3/19/10
00280 
00281     // OK, now scan for octal escape sequences like \\012 (where the '\'
00282     // is itself escaped). This type of attribute value comes from the netCDF
00283     // handler and maybe others. Assumption: The '\' will always appear as
00284     // in its escaped form: '\\'. NB: Both backslashes must be escaped in the
00285     // C++ string.
00286     string octal_escape = "\\\\";
00287     i = 0;
00288     string::size_type length = in.length();
00289     while ((i = in.find(octal_escape, i)) != string::npos) {
00290         // Get the three octal digits following the '\\0'
00291         string::size_type j = i + 2;
00292         if (j + 1 >= length)  // Check that we're not past the end
00293             break;
00294         string octal_digits = in.substr(j, 3);
00295         // convert to a &#xdd; XML escape
00296         string hex_escape = string("&#x");
00297         hex_escape.append(octal_to_hex(octal_digits));
00298         hex_escape.append(string(";"));
00299 
00300         // replace the octal escape with an XML/hex escape
00301         in.replace(i, 5, hex_escape);
00302 
00303         // increment i
00304         i += 6;
00305     }
00306 #endif
00307     return in;
00308 }
00309 
00315 string
00316 xml2id(string in)
00317 {
00318     string::size_type i = 0;
00319 
00320     while ((i = in.find("&gt;", i)) != string::npos)
00321         in.replace(i, 4, ">");
00322 
00323     i = 0;
00324     while ((i = in.find("&lt;", i)) != string::npos)
00325         in.replace(i, 4, "<");
00326 
00327     i = 0;
00328     while ((i = in.find("&amp;", i)) != string::npos)
00329         in.replace(i, 5, "&");
00330 
00331     i = 0;
00332     while ((i = in.find("&apos;", i)) != string::npos)
00333         in.replace(i, 6, "'");
00334 
00335     i = 0;
00336     while ((i = in.find("&quot;", i)) != string::npos)
00337         in.replace(i, 6, "\"");
00338 
00339     return in;
00340 }
00341 
00347 string
00348 esc2underscore(string s)
00349 {
00350     string::size_type pos;
00351     while ((pos = s.find('%')) != string::npos)
00352         s.replace(pos, 3, "_");
00353 
00354     return s;
00355 }
00356 
00357 
00361 string
00362 escattr(string s)
00363 {
00364     const string printable = " ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789~`!@#$%^&*()_-+={[}]|\\:;<,>.?/'\"";
00365     const string ESC = "\\";
00366     const string DOUBLE_ESC = ESC + ESC;
00367     const string QUOTE = "\"";
00368     const string ESCQUOTE = ESC + QUOTE;
00369 
00370     // escape non-printing characters with octal escape
00371     string::size_type ind = 0;
00372     while ((ind = s.find_first_not_of(printable, ind)) != s.npos)
00373         s.replace(ind, 1, ESC + octstring(s[ind]));
00374 
00375     // escape \ with a second backslash
00376     ind = 0;
00377     while ((ind = s.find(ESC, ind)) != s.npos) {
00378         s.replace(ind, 1, DOUBLE_ESC);
00379         ind += DOUBLE_ESC.length();
00380     }
00381 
00382     // escape " with backslash
00383     ind = 0;
00384     while ((ind = s.find(QUOTE, ind)) != s.npos) {
00385         s.replace(ind, 1, ESCQUOTE);
00386         ind += ESCQUOTE.length();
00387     }
00388 
00389     return s;
00390 }
00391 
00400 string
00401 unescattr(string s)
00402 {
00403     Regex octal("\\\\[0-3][0-7][0-7]");  // matches 4 characters
00404     Regex esc_quote("\\\\\"");  // matches 3 characters
00405     Regex esc_esc("\\\\\\\\");      // matches 2 characters
00406     const string ESC = "\\";
00407     const string QUOTE = "\"";
00408     int matchlen;
00409     unsigned int index;
00410 
00411     DBG(cerr << "0XX" << s << "XXX" << endl);
00412     // unescape any escaped backslashes
00413     index = esc_esc.search(s.c_str(), s.length(), matchlen, 0);
00414     while (index < s.length()) {
00415         DBG(cerr << "1aXX" << s << "XXX index: " << index << endl);
00416         s.replace(index, 2, ESC);
00417         DBG(cerr << "1bXX" << s << "XXX index: " << index << endl);
00418         index = esc_esc.search(s.c_str(), s.length(), matchlen, 0);
00419     }
00420 
00421     // unescape any escaped double quote characters
00422     index = esc_quote.search(s.c_str(), s.length(), matchlen, 0);
00423     while (index < s.length()) {
00424         s.replace(index, 2, QUOTE);
00425         DBG(cerr << "2XX" << s << "XXX index: " << index << endl);
00426         index = esc_quote.search(s.c_str(), s.length(), matchlen, 0);
00427     }
00428 
00429     // unescape octal characters
00430     index = octal.search(s.c_str(), s.length(), matchlen, 0);
00431     while (index < s.length()) {
00432         s.replace(index, 4, unoctstring(s.substr(index + 1, 3)));
00433         DBG(cerr << "3XX" << s << "XXX index: " << index << endl);
00434         index = octal.search(s.c_str(), s.length(), matchlen, 0);
00435     }
00436 
00437     DBG(cerr << "4XX" << s << "XXX" << endl);
00438     return s;
00439 }
00440 
00441 string
00442 munge_error_message(string msg)
00443 {
00444     // First, add enclosing quotes if needed.
00445     if (*msg.begin() != '"')
00446         msg.insert(msg.begin(), '"');
00447     if (*(msg.end() - 1) != '"')
00448         msg += "\"";
00449 
00450     // Now escape any internal double quotes that aren't escaped.
00451     string::iterator miter;
00452     for (miter = msg.begin() + 1; miter != msg.end() - 1; miter++)
00453         if (*miter == '"' && *(miter - 1) != '\\')
00454             miter = msg.insert(miter, '\\');
00455 
00456     return msg;
00457 }
00458 
00463 string
00464 escape_double_quotes(string source)
00465 {
00466     string::size_type idx = 0;
00467     while((idx = source.find('\"', idx)) != string::npos) {
00468         source.replace(idx, 1, "\\\""); // a backslash and a double quote
00469         idx += 2;
00470     }
00471 
00472     return source;
00473 }
00474 
00480 string
00481 unescape_double_quotes(string source)
00482 {
00483     string::size_type idx = 0;
00484     while((idx = source.find("\\\"", idx)) != string::npos) {
00485         source.replace(idx, 2, "\""); // a backslash and a double quote
00486         ++idx;
00487     }
00488 
00489     return source;
00490 }
00491 
00492 } // namespace libdap
00493