/** @file
Parser: String class part: untaint mechanizm.
Copyright(c) 2001, 2002 ArtLebedev Group (http://www.artlebedev.com)
Author: Alexandr Petrosian <paf@design.ru> (http://paf.design.ru)
$Id: untaint.C,v 1.100 2002/04/01 09:37:51 paf Exp $
*/
#include "pa_pool.h"
#include "pa_string.h"
#include "pa_hash.h"
#include "pa_exception.h"
#include "pa_table.h"
#include "pa_globals.h"
#include "pa_sql_connection.h"
#include "pa_dictionary.h"
#include "pa_common.h"
#include "pa_charset.h"
//#define DEBUG_STRING_APPENDS_VS_EXPANDS
#ifdef DEBUG_STRING_APPENDS_VS_EXPANDS
ulong string_string_shortcut_economy=0;
#endif
#define escape(action) \
{ \
const char *src=row->item.ptr; \
for(int size=row->item.size; size--; src++) \
action \
}
#define _default default: *dest++=*src; break
#define encode(need_encode_func, prefix) \
if(need_encode_func(*src)) { \
static const char *hex="0123456789ABCDEF"; \
char chunk[3]={prefix}; \
chunk[1]=hex[((unsigned char)*src)/0x10]; \
chunk[2]=hex[((unsigned char)*src)%0x10]; \
memcpy(dest, chunk, 3); dest+=3; \
} else \
*dest++=*src; \
break
#define to_char(c) *dest++=c
#define to_string(b, bsize) \
memcpy(dest, b, bsize); \
dest+=bsize; \
inline bool need_file_encode(unsigned char c){
// theoretical problem with, for instance, "_2B" and "." fragments,
// they would yield the same
// because need_file_encode('_')=false
// but we need to delete such files somehow, getting names from ^index
if((c>='0') &&(c<='9') ||(c>='A') &&(c<='Z') ||(c>='a') &&(c<='z'))
return false;
return !strchr(
" _./()-"
#ifdef WIN32
":\\~"
#endif
, c);
}
inline bool need_uri_encode(unsigned char c){
if((c>='0') &&(c<='9') ||(c>='A') &&(c<='Z') ||(c>='a') &&(c<='z'))
return false;
return !strchr("_-./", c);
}
inline bool need_http_header_encode(unsigned char c){
if(strchr(" , :", c))
return false;
return need_uri_encode(c);
}
//
static const char * String_Untaint_lang_name[]={
"U", ///< zero value handy for hash lookup @see untaint_lang_name2enum
"C", ///< clean
"T", ///< tainted, untaint language as assigned later
// untaint languages. assigned by ^untaint[lang]{...}
"P",
/**<
leave language built into string being appended.
just a flag, that value not stored
*/
"A", ///< leave all characters intact
"F", ///< file specification
"H", ///< ext in HTTP response header
"M", ///< text in mail header
"URI", ///< text in uri
"T", ///< ^table:set body
"SQL", ///< ^table:sql body
"JS", ///< JavaScript code
"XML", ///< ^dom:set xml
"HTML" ///< HTML code (for editing)
};
// String
/*
HTTP-header = field-name ":" [ field-value ] CRLF
field-name = token
field-value = *( field-content | LWS )
field-content = <the OCTETs making up the field-value
and consisting of either *TEXT or combinations
of token, tspecials, and quoted-string>
word = token | quoted-string
token = 1*<any CHAR except CTLs or tspecials>
tspecials = "(" | ")" | "<" | ">" | "@"
| "," | ";" | ":" | "\" | <">
| "/" | "[" | "]" | "?" | "="
| "{" | "}" | SP | HT
SP = <US-ASCII SP, space (32)>
HT = <US-ASCII HT, horizontal-tab (9)>
LWS = [CRLF] 1*( SP | HT )
TEXT = <any OCTET except CTLs,
but including LWS>
quoted-pair = "\" CHAR
if(strchr("()<>@,;:\\\"/[]?={} \t", *ptr))
*/
inline bool need_quote_http_header(const char *ptr, size_t size) {
for(; size--; ptr++)
if(strchr(";\\\"= \t" /* excluded ()<>@, :/ ? []{} */, *ptr))
return true;
return false;
}
//#include "pa_sapi.h"
/**
appends other String,
marking all tainted pieces of it with @a lang.
or marking ALL pieces of it with a @a lang when @a forced to,
and propagating OPTIMIZE language bit.
using architecture advantage: after string-to-string-append string never modified.
algorithm:
if no language-change specified and src not yet appended to some other string[last_chunk!=0]
shrinking dest last_chunk[preparing it for linking],
///shrinking src last_chunk[preparing it to be linked, consequent dest.appends would go there],
linking[dest.last_chunk = src.head]
if some language-change specified or src already appended to some other string[last_chunk==0]
cloning pieces.
*/
String& String::append(const String& src, uchar lang, bool forced) {
if(!last_chunk) // growth stopped [we're appended as string to somebody]
throw Exception(0,
this,
"string growth stopped (append string)");
if(src.is_empty())
return *this;
// without language-chage, not-appended-before, big[not fitting our tail] string?
if(lang==UL_PASS_APPENDED
&& src.last_chunk
&& (uint(&last_chunk->rows[last_chunk->count]-append_here) < src.used_rows())) {
#ifdef DEBUG_STRING_APPENDS_VS_EXPANDS
string_string_shortcut_economy+=src.used_rows()*sizeof(String::Chunk::Row);
#endif
// using fact:
// src.head.count initally equeals this.head.count and shrinks-only,
// so can't be more than this.head.count,
// which means that we know that
// src.head would fit into this.head
if(is_empty()) { // our head is empty
// they have more than head? we need all head : we need only filled-part of head
Chunk *src_head_link=src.head.rows[src.head.count].link;
size_t head_count=src_head_link?src.head.count:(src.append_here-src.head.rows);
// "your head is my head"
memcpy(head.rows, src.head.rows, sizeof(Chunk::Row)*(head_count));
if(src_head_link) {
// "your body is my body"
head.rows[head.count=head_count].link=src_head_link;
// "your last_chunk is mine now"
last_chunk=src.last_chunk;
// "your append_here is mine now"
append_here=src.append_here;
} else {
// "your last_chunk is mine now"
last_chunk=&head;
// "your append_here is recalc-mine now"
append_here=head.rows+head_count;
}
} else { // our head contains something
// "chopping off my tail-reserve"
last_chunk->count=append_here-last_chunk->rows;
// "you is my tail"
append_here->link=&src.head;
// "your last_chunk is mine now"
last_chunk=src.last_chunk;
// "your append_here is mine now"
append_here=src.append_here;
}
// stop-growing mark
src.last_chunk=0;
return *this;
}
// manually unrolled code to avoid do{if(const)} constructs
if(forced)
STRING_SRC_FOREACH_ROW(
APPEND(row->item.ptr, row->item.size,
lang, //forcing passed lang
row->item.origin.file, row->item.origin.line);
)
else if(lang==UL_PASS_APPENDED)
STRING_SRC_FOREACH_ROW(
APPEND(row->item.ptr, row->item.size,
row->item.lang, // passing item's lang
row->item.origin.file, row->item.origin.line);
)
else if(lang&UL_OPTIMIZE_BIT) // main idea here
// tainted piece would get OPTIMIZED bit from 'lang'
// clean piece would be marked OPTIMIZED manually
// pieces with determined languages [not tainted|clean] would retain theirs langs
STRING_SRC_FOREACH_ROW(
APPEND(row->item.ptr, row->item.size,
row->item.lang==UL_TAINTED?lang:(
row->item.lang==UL_CLEAN?UL_CLEAN|UL_OPTIMIZE_BIT: // ORing with OPTIMIZED flag
row->item.lang
),
row->item.origin.file, row->item.origin.line);
)
else
STRING_SRC_FOREACH_ROW(
APPEND(row->item.ptr, row->item.size,
row->item.lang==UL_TAINTED?lang:row->item.lang,
row->item.origin.file, row->item.origin.line);
);
/*
for(Chunk::Row *row=last_chunk->rows; row<append_here; row++)
if(row->link==(void*)0xcdcdcdcd)
_asm int 3;*/
return *this;
}
size_t String::cstr_bufsize(Untaint_lang lang,
SQL_Connection *connection,
Charset *buf_charset) const {
size_t dest=1; // for terminating 0
STRING_FOREACH_ROW(
uchar to_lang=lang==UL_UNSPECIFIED?row->item.lang:lang;
switch(to_lang & ~UL_OPTIMIZE_BIT) {
case UL_CLEAN:
case UL_TAINTED:
case UL_AS_IS:
// clean piece
// tainted piece, but undefined untaint language
// for VString.as_double of tainted values
// for ^process{body} evaluation
// tainted, untaint language: as-is
dest+=row->item.size;
break;
case UL_FILE_SPEC:
// tainted, untaint language: file [name]
dest+=row->item.size*3/* worst: Z->%XX */;
break;
case UL_URI:
// tainted, untaint language: uri
dest+=row->item.size*6*3/* worst utf8 x worst Z->%XX */;
break;
case UL_HTTP_HEADER:
// tainted, untaint language: http-field-content-text
dest+=row->item.size*3/* worst: Z->%XX */;
break;
case UL_MAIL_HEADER:
// tainted, untaint language: mail-header
if(buf_charset) {
// Subject: Re: parser3: =?koi8-r?Q?=D3=C5=CD=C9=CE=C1=D2?=
dest+=
row->item.size*3+
buf_charset->name().size()+MAX_STRING/* worst: =?charset?Q?=%XX?= */;
} else
dest+=row->item.size;
break;
case UL_TABLE:
// tainted, untaint language: table
dest+=row->item.size;
break;
case UL_SQL:
// tainted, untaint language: sql
if(connection)
dest+=connection->quote(0, row->item.ptr, row->item.size);
break;
case UL_JS:
escape(switch(*src) {
case '"': case '\'': case '\n': case '\\': case '\xFF':
dest+=2; break;
default:
dest++; break;
});
break;
case UL_XML:
escape(switch(*src) {
case '&': case '>': case '<': case '"': case '\'':
dest+= 6; break;
default:
dest++; break;
});
break;
case UL_HTML:
escape(switch(*src) {
case '&':
case '>':
case '<':
case '"':
dest+=6; break;
default:
dest++; break;
});
break;
}
);
return dest;
}
char *String::store_to(char *dest, Untaint_lang lang,
SQL_Connection *connection,
Charset *store_to_charset,
const char *store_to_charset_name) const {
// WARNING:
// before any changes check cstr_bufsize first!!!
bool whitespace=true;
STRING_FOREACH_ROW(
uchar to_lang=lang==UL_UNSPECIFIED?row->item.lang:lang;
char *start=dest;
switch(to_lang & ~UL_OPTIMIZE_BIT) {
case UL_CLEAN:
case UL_TAINTED:
case UL_AS_IS:
// clean piece
// tainted piece, but undefined untaint language
// for VString.as_double of tainted values
// for ^process{body} evaluation
// tainted, untaint language: as-is
memcpy(dest, row->item.ptr, row->item.size);
dest+=row->item.size;
break;
case UL_FILE_SPEC:
// tainted, untaint language: file [name]
escape(
encode(need_file_encode, '_');
);
break;
case UL_URI:
// tainted, untaint language: uri
const void *client_ptr;
size_t client_size;
Charset::transcode(pool(),
pool().get_source_charset(), row->item.ptr, row->item.size,
pool().get_client_charset(), client_ptr, client_size);
{
const char *src=(const char *)client_ptr;
for(int size=client_size; size--; src++)
switch(*src) {
case ' ': to_char('+'); break;
default: encode(need_uri_encode, '%');
};
}
break;
case UL_HTTP_HEADER:
// tainted, untaint language: http-field-content-text
escape(switch(*src) {
case ' ': to_char('+'); break;
default: encode(need_uri_encode, '%');
});
break;
case UL_MAIL_HEADER:
// tainted, untaint language: mail-header
if(store_to_charset && store_to_charset_name) {
const void *mail_ptr;
size_t mail_size;
Charset::transcode(pool(),
pool().get_source_charset(), row->item.ptr, row->item.size,
*store_to_charset, mail_ptr, mail_size);
// Subject: Re: parser3: =?koi8-r?Q?=D3=C5=CD=C9=CE=C1=D2?=
const char *src=(const char *)mail_ptr;
bool to_quoted_printable=false;
for(int size=mail_size; size--; src++) {
if(*src & 0x80 // starting quote-printable-encoding on first 8bit char
|| (to_quoted_printable && (*src=='?' || *src=='=')) // additionally encoding '?' and '|'
) {
if(!to_quoted_printable) {
dest+=sprintf(dest, "=?%s?Q?", store_to_charset_name);
to_quoted_printable=true;
}
dest+=sprintf(dest, "=%02X", *src & 0xFF);
} else {
*dest++=*src;
}
}
if(to_quoted_printable) // close
dest+=sprintf(dest, "?=");
} else {
memcpy(dest, row->item.ptr, row->item.size);
dest+=row->item.size;
}
break;
case UL_TABLE:
// tainted, untaint language: table
escape(switch(*src) {
case '\t': to_char(' '); break;
case '\n': to_char(' '); break;
_default;
});
break;
case UL_SQL:
// tainted, untaint language: sql
if(connection)
dest+=connection->quote(dest, row->item.ptr, row->item.size);
else
throw Exception(0,
this,
"untaint in SQL language failed - no connection specified");
break;
case UL_JS:
escape(switch(*src) {
case '"': to_string("\\\"", 2); break;
case '\'': to_string("\\'", 2); break;
case '\n': to_string("\\n", 2); break;
case '\\': to_string("\\\\", 2); break;
case '\xFF': to_string("\\\xFF", 2); break;
_default;
});
break;
case UL_XML:
escape(switch(*src) {
case '&': to_string("&", 5); break;
case '>': to_string(">", 4); break;
case '<': to_string("<", 4); break;
case '"': to_string(""", 6); break;
case '\'': to_string("'", 6); break;
_default;
});
break;
case UL_HTML:
escape(switch(*src) {
case '&': to_string("&", 5); break;
case '>': to_string(">", 4); break;
case '<': to_string("<", 4); break;
case '"': to_string(""", 6); break;
_default;
});
break;
default:
throw Exception(0,
this,
"unknown untaint language #%d",
static_cast<int>(row->item.lang)); // sould never
break; // never
}
if(to_lang & UL_OPTIMIZE_BIT) {
// optimizing whitespace
char *stop=dest; dest=start;
for(char *src=start; src<stop; src++)
switch(*src) {
// of all consequent white space chars leaving only first one
case ' ': case '\r': case '\n': case '\t':
if(!whitespace) {
*dest++=*src;
whitespace=true;
}
break;
default:
whitespace=false;
*dest++=*src;
break;
};
} else // piece without optimization
whitespace=false;
);
return dest;
}
char *String::cstr_debug_origins() const {
//_asm int 3;
char *result=(char *)malloc(size()+used_rows()*MAX_STRING*2);
char *dest=result;
STRING_FOREACH_ROW(
IFNDEF_NO_STRING_ORIGIN(
if(row->item.origin.file)
dest+=sprintf(dest, ORIGIN_FILE_LINE_FORMAT,
row->item.origin.file,
1+row->item.origin.line);
else
dest+=sprintf(dest, "<unknown>");
);
uchar show_lang=row->item.lang & ~UL_OPTIMIZE_BIT;
if(show_lang>=sizeof(String_Untaint_lang_name)/sizeof(String_Untaint_lang_name[0]))
throw Exception(0,
this,
"unknown untaint language #%d",
static_cast<int>(show_lang)); // sould never
dest+=sprintf(dest, "#%s%s: ",
String_Untaint_lang_name[show_lang],
row->item.lang & UL_OPTIMIZE_BIT?".O":"");
char *dest_after_origins=dest;
memcpy(dest, row->item.ptr, row->item.size);
dest+=row->item.size;
remove_crlf(dest_after_origins, dest);
to_char('\n');
);
*dest=0;
return result;
}
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