#ifndef lint
static char rcsid[] = "@(#$Id: mimeparse.cpp,v 1.3 2005-03-25 09:40:28 dockes Exp $ (C) 2004 J.F.Dockes";
#endif
#ifndef TEST_MIMEPARSE
#include <string>
#include <ctype.h>
#include <stdio.h>
#include <ctype.h>
#include "mimeparse.h"
using namespace std;
// Parsing a header value. Only content-type has parameters, but
// others are compatible with content-type syntax, only, parameters
// are not used. So we can parse all like content-type:
// headertype: value [; paramname=paramvalue] ...
// Value and paramvalues can be quoted strings, and there can be
// comments in there
// The lexical token returned by find_next_token
class Lexical {
public:
enum kind {none, token, separator};
kind what;
string value;
string error;
char quote;
Lexical() : what(none), quote(0) {}
void reset() {what = none; value.erase(); error.erase();quote = 0;}
};
// Skip mime comment. This must be called with in[start] == '('
int skip_comment(const string &in, unsigned int start, Lexical &lex)
{
int commentlevel = 0;
for (; start < in.size(); start++) {
if (in[start] == '\\') {
// Skip escaped char.
if (start+1 < in.size()) {
start++;
continue;
} else {
lex.error.append("\\ at end of string ");
return string::npos;
}
}
if (in[start] == '(')
commentlevel++;
if (in[start] == ')') {
if (--commentlevel == 0)
break;
}
}
if (start == in.size()) {
lex.error.append("Unclosed comment ");
return string::npos;
}
return start;
}
// Skip initial whitespace and (possibly nested) comments.
int skip_whitespace_and_comment(const string &in, unsigned int start,
Lexical &lex)
{
while (1) {
if ((start = in.find_first_not_of(" \t\r\n", start)) == string::npos)
return in.size();
if (in[start] == '(') {
if ((start = skip_comment(in, start, lex)) == string::npos)
return string::npos;
} else {
break;
}
}
return start;
}
/// Find next token in mime header value string.
/// @return the next starting position in string, string::npos for error
/// (ie unbalanced quoting)
/// @param in the input string
/// @param start the starting position
/// @param lex the returned token and its description
/// @param delims separators we should look for
int find_next_token(const string &in, unsigned int start,
Lexical &lex, string delims = ";=")
{
char oquot, cquot;
start = skip_whitespace_and_comment(in, start, lex);
if (start == string::npos || start == in.size())
return start;
// Begins with separator ? return it.
unsigned int delimi = delims.find_first_of(in[start]);
if (delimi != string::npos) {
lex.what = Lexical::separator;
lex.value = delims[delimi];
return start+1;
}
// Check for start of quoted string
oquot = in[start];
switch (oquot) {
case '<': cquot = '>';break;
case '"': cquot = '"';break;
default: cquot = 0; break;
}
if (cquot != 0) {
// Quoted string parsing
unsigned int end;
start++; // Skip quote character
for (end = start;end < in.size() && in[end] != cquot; end++) {
if (in[end] == '\\') {
// Skip escaped char.
if (end+1 < in.size()) {
end++;
} else {
// backslash at end of string: error
lex.error.append("\\ at end of string ");
return string::npos;
}
}
}
if (end == in.size()) {
// Found end of string before closing quote character: error
lex.error.append("Unclosed quoted string ");
return string::npos;
}
lex.what = Lexical::token;
lex.value = in.substr(start, end-start);
lex.quote = oquot;
return ++end;
} else {
unsigned int end = in.find_first_of(delims + " \t(", start);
lex.what = Lexical::token;
lex.quote = 0;
if (end == string::npos) {
end = in.size();
lex.value = in.substr(start);
} else {
lex.value = in.substr(start, end-start);
}
return end;
}
}
void stringtolower(string &out, const string& in)
{
for (unsigned int i = 0; i < in.size(); i++)
out.append(1, char(tolower(in[i])));
}
bool parseMimeHeaderValue(const string& value, MimeHeaderValue& parsed)
{
parsed.value.erase();
parsed.params.clear();
Lexical lex;
unsigned int start = 0;
start = find_next_token(value, start, lex);
if (start == string::npos || lex.what != Lexical::token)
return false;
parsed.value = lex.value;
for (;;) {
string paramname, paramvalue;
lex.reset();
start = find_next_token(value, start, lex);
if (start == value.size())
return true;
if (start == string::npos)
return false;
if (lex.what == Lexical::separator && lex.value[0] == ';')
continue;
if (lex.what != Lexical::token)
return false;
stringtolower(paramname, lex.value);
start = find_next_token(value, start, lex);
if (start == string::npos || lex.what != Lexical::separator ||
lex.value[0] != '=')
return false;
start = find_next_token(value, start, lex);
if (start == string::npos || lex.what != Lexical::token)
return false;
paramvalue = lex.value;
parsed.params[paramname] = paramvalue;
}
return true;
}
// Decode a string encoded with quoted-printable encoding.
bool qp_decode(const string& in, string &out)
{
out.reserve(in.length());
unsigned int ii;
for (ii = 0; ii < in.length(); ii++) {
if (in[ii] == '=') {
ii++; // Skip '='
if(ii >= in.length() - 1) { // Need at least 2 more chars
break;
} else if (in[ii] == '\r' && in[ii+1] == '\n') { // Soft nl, skip
ii++;
} else if (in[ii] != '\n' && in[ii] != '\r') { // decode
char c = in[ii];
char co;
if(c >= 'A' && c <= 'F') {
co = char((c - 'A' + 10) * 16);
} else if (c >= 'a' && c <= 'f') {
co = char((c - 'a' + 10) * 16);
} else if (c >= '0' && c <= '9') {
co = char((c - '0') * 16);
} else {
return false;
}
if(++ii >= in.length())
break;
c = in[ii];
if (c >= 'A' && c <= 'F') {
co += char(c - 'A' + 10);
} else if (c >= 'a' && c <= 'f') {
co += char(c - 'a' + 10);
} else if (c >= '0' && c <= '9') {
co += char(c - '0');
} else {
return false;
}
out += co;
}
} else {
out += in[ii];
}
}
return true;
}
// This is adapted from FreeBSD's code.
static const char Base64[] =
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
static const char Pad64 = '=';
bool base64_decode(const string& in, string& out)
{
int io = 0, state = 0, ch;
char *pos;
unsigned int ii = 0;
out.reserve(in.length());
for (ii = 0; ii < in.length(); ii++) {
ch = in[ii];
if (isspace((unsigned char)ch)) /* Skip whitespace anywhere. */
continue;
if (ch == Pad64)
break;
pos = strchr(Base64, ch);
if (pos == 0) /* A non-base64 character. */
return false;
switch (state) {
case 0:
out[io] = (pos - Base64) << 2;
state = 1;
break;
case 1:
out[io] |= (pos - Base64) >> 4;
out[io+1] = ((pos - Base64) & 0x0f) << 4 ;
io++;
state = 2;
break;
case 2:
out[io] |= (pos - Base64) >> 2;
out[io+1] = ((pos - Base64) & 0x03) << 6;
io++;
state = 3;
break;
case 3:
out[io] |= (pos - Base64);
io++;
state = 0;
break;
default:
return false;
}
}
/*
* We are done decoding Base-64 chars. Let's see if we ended
* on a byte boundary, and/or with erroneous trailing characters.
*/
if (ch == Pad64) { /* We got a pad char. */
ch = in[ii++]; /* Skip it, get next. */
switch (state) {
case 0: /* Invalid = in first position */
case 1: /* Invalid = in second position */
return false;
case 2: /* Valid, means one byte of info */
/* Skip any number of spaces. */
for (; ii < in.length(); ch = in[ii++])
if (!isspace((unsigned char)ch))
break;
/* Make sure there is another trailing = sign. */
if (ch != Pad64)
return false;
ch = in[ii++]; /* Skip the = */
/* Fall through to "single trailing =" case. */
/* FALLTHROUGH */
case 3: /* Valid, means two bytes of info */
/*
* We know this char is an =. Is there anything but
* whitespace after it?
*/
for ((void)NULL; ii < in.length(); ch = in[ii++])
if (!isspace((unsigned char)ch))
return false;
/*
* Now make sure for cases 2 and 3 that the "extra"
* bits that slopped past the last full byte were
* zeros. If we don't check them, they become a
* subliminal channel.
*/
if (out[io] != 0)
return false;
}
} else {
/*
* We ended by seeing the end of the string. Make sure we
* have no partial bytes lying around.
*/
if (state != 0)
return false;
}
return true;
}
#else
#include <string>
#include "mimeparse.h"
using namespace std;
int
main(int argc, const char **argv)
{
#if 0
// const char *tr = "text/html; charset=utf-8; otherparam=garb";
const char *tr = "text/html;charset = UTF-8 ; otherparam=garb; \n"
"QUOTEDPARAM=\"quoted value\"";
MimeHeaderValue parsed;
if (!parseMimeHeaderValue(tr, parsed)) {
fprintf(stderr, "PARSE ERROR\n");
}
printf("'%s' \n", parsed.value.c_str());
map<string, string>::iterator it;
for (it = parsed.params.begin();it != parsed.params.end();it++) {
printf(" '%s' = '%s'\n", it->first.c_str(), it->second.c_str());
}
#elif 0
const char *qp = "=41=68 =e0 boire=\r\n continue 1ere\ndeuxieme\n\r3eme "
"agrave is: '=E0' probable skipped decode error: =\n"
"Actual decode error =xx this wont show";
string out;
if (!qp_decode(string(qp), out)) {
fprintf(stderr, "qp_decode returned error\n");
}
printf("Decoded: '%s'\n", out.c_str());
#else
//'C'est � boire qu'il nous faut �viter l'exc�s.'
//'Deuxi�me ligne'
//'Troisi�me ligne'
//'Et la fin (pas de nl). '
const char *b64 =
"Qydlc3Qg4CBib2lyZSBxdSdpbCBub3VzIGZhdXQg6XZpdGVyIGwnZXhj6HMuCkRldXhp6G1l\r\n"
"IGxpZ25lClRyb2lzaehtZSBsaWduZQpFdCBsYSBmaW4gKHBhcyBkZSBubCkuIA==\r\n";
string out;
if (!base64_decode(string(b64), out)) {
fprintf(stderr, "base64_decode returned error\n");
}
printf("Decoded: '%s'\n", out.c_str());
#endif
}
#endif // TEST_MIMEPARSE