--- parser3/src/main/untaint.C 2001/03/25 08:52:37 1.15 +++ parser3/src/main/untaint.C 2001/03/29 08:34:48 1.26 @@ -5,7 +5,7 @@ Author: Alexander Petrosyan (http://design.ru/paf) - $Id: untaint.C,v 1.15 2001/03/25 08:52:37 paf Exp $ + $Id: untaint.C,v 1.26 2001/03/29 08:34:48 paf Exp $ */ #include "pa_config_includes.h" @@ -16,21 +16,13 @@ #include "pa_exception.h" #include "pa_table.h" -#define escape(cases) \ +#define escape(action) \ { \ const char *src=row->item.ptr; \ for(int size=row->item.size; size--; src++) \ - switch(*src) { \ - cases \ - } \ + action \ } -#define to_char(a, c) case a: *dest++=c; break #define _default default: *dest++=*src; break -#define to_string(a, b, bsize) \ - case a: \ - strncpy(dest, b, bsize); \ - dest+=bsize; \ - break #define encode(need_encode_func, prefix) \ default: \ if(need_encode_func(*src)) { \ @@ -42,6 +34,10 @@ } else \ *dest++=*src; \ break +#define to_char(c) *dest++=c +#define to_string(b, bsize) \ + strncpy(dest, b, bsize); \ + dest+=bsize; \ inline bool need_file_encode(unsigned char c){ if((c>='0') &&(c<='9') ||(c>='A') &&(c<='Z') ||(c>='a') &&(c<='z')) @@ -56,7 +52,7 @@ inline bool need_uri_encode(unsigned cha return !strchr("_-./", c); } inline bool need_header_encode(unsigned char c){ - if(strchr(" ,:", c)) + if(strchr(" , :", c)) return false; return need_uri_encode(c); @@ -75,10 +71,11 @@ static bool typo_present(Array::Item *va partial==1; // typo left column starts 'src' } -/// @todo optimize whitespaces for all but 'html' +/// @todo @b now: optimize whitespaces for all but 'html' char *String::store_to(char *dest) const { // $MAIN:html-typo table - Table *typo_table=static_cast(pool().tag()); + Table *user_typo_table=static_cast
(pool().tag()); + Table *typo_table=user_typo_table?user_typo_table:default_typo_table; const Chunk *chunk=&head; do { @@ -94,7 +91,7 @@ char *String::store_to(char *dest) const // clean piece case UL_YES: // tainted piece, but undefined untaint language - // for VString.get_double of tainted values + // for VString.as_double of tainted values // for ^process{body} evaluation case UL_AS_IS: // tainted, untaint language: as-is @@ -103,31 +100,31 @@ char *String::store_to(char *dest) const break; case UL_FILE_NAME: // tainted, untaint language: file [name] - escape( - to_char(' ', '_'); + escape(switch(*src) { + case ' ': to_char('_'); break; encode(need_file_encode, '-'); - ); + }); break; case UL_URI: // tainted, untaint language: uri - escape( - to_char(' ', '+'); + escape(switch(*src) { + case ' ': to_char('+'); break; encode(need_uri_encode, '%'); - ); + }); break; case UL_HEADER: // tainted, untaint language: header - escape( + escape(switch(*src) { encode(need_header_encode, '%'); - ); + }); break; case UL_TABLE: // tainted, untaint language: table - escape( - to_char('\t', ' '); - to_char('\n', ' '); + escape(switch(*src) { + case '\t': to_char(' '); break; + case '\n': to_char(' '); break; _default; - ); + }); break; case UL_SQL: // tainted, untaint language: sql @@ -136,94 +133,101 @@ char *String::store_to(char *dest) const dest+=row->item.size; break; case UL_JS: - escape( - to_string('"', "\\\"", 2); - to_string('\'', "\\'", 2); - to_string('\n', "\\n", 2); - to_string('\\', "\\\\", 2); - to_string('\xFF', "\\\xFF", 2); + 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_HTML: - escape( - to_string('&', "&", 5); - to_string('>', ">", 4); - to_string('<', "<",4); - to_string('"', """,6); - to_char('\t', ' '); - //TODO: XSLT to_string('\'', "'", 6) + escape(switch(*src) { + case '&': to_string("&", 5); break; + case '>': to_string(">", 4); break; + case '<': to_string("<", 4); break; + case '"': to_string(""", 6); break; + //TODO: XSLT case '\'': to_string("'", 6); break; _default; - ); + }); break; case UL_HTML_TYPO: { // tainted, untaint language: html-typo - char *html=(char *)malloc(size()*6/*""" the longest possible*/+1); - size_t html_size; + char *html_for_typo=(char *)malloc(size()*2/* '\n' -> '\' 'n' */+1); + // note: + // there still is a possibility that user + // would not replace \n as she supposed to + // and rather replace \ and n into huge strings + // thus causing memory overrun + // this can be dealed by allocating *2 memory, but that's too expensive + // todo parser4: fix that + size_t html_for_typo_size; { // local dest - char *dest=html; - escape( - to_string('&', "&", 5); - to_string('>', ">", 4); - to_string('<', "<",4); - to_string('"', """,6); - to_char('\t', ' '); - to_string('\r', "", 0); // todo: check mac & linux browsers' textarea - to_string('\n', "\\n", 2); // convinient name for typo match - //TODO: XSLT to_string('\'', "'", 6) + char *dest=html_for_typo; + escape(switch(*src) { + // convinient name for typo match "\n" + case '\r': + if(typo_table) { + *dest++='\\'; *dest++='n'; // \r -> \n + if(src[1]=='\n') { // \r\n -> remove \n + size--; src++; + } + } + break; + case '\n': + if(typo_table) + to_string("\\n", 2); + break; + //TODO: XSLT case '\'': to_string("'", 6); break; _default; - ); + }); *dest=0; - html_size=dest-html; + html_for_typo_size=dest-html_for_typo; } // typo table replacements - if(typo_table) { - const char *src=html; - do { - // there is a row where first column starts 'src' - if(Table::Item *item=typo_table->first_that(typo_present, src)) { - // get a=>b values - const String& a=*static_cast(item)->get_string(0); - const String& b=*static_cast(item)->get_string(1); - // empty 'a' check - if(a.size()==0) { - pool().set_tag(0); // avoid recursion - THROW(0, 0, - &a, - "typo table first column elements must not be empty"); - } - // overflow check: - // b allowed to be max UNTAINT_TIMES_BIGGER then a - if(b.size()>UNTAINT_TIMES_BIGGER*a.size()) { - pool().set_tag(0); // avoid recursion - THROW(0, 0, - &b, - "is %g times longer then '%s', " - "while maximum, handled by Parser, is %d", - ((double)b.size())/a.size(), - a.cstr(), - UNTAINT_TIMES_BIGGER); - } - - // skip 'a' in 'src' - src+=a.size(); - // write 'b' to 'dest' - b.store_to(dest); - dest+=b.size(); - } else - *dest++=*src++; - } while(*src); - } else { - memcpy(dest, html, html_size); - dest+=html_size; - } + const char *src=html_for_typo; + do { + // there is a row where first column starts 'src' + if(Table::Item *item=typo_table->first_that(typo_present, src)) { + // get a=>b values + const String& a=*static_cast(item)->get_string(0); + const String& b=*static_cast(item)->get_string(1); + // empty 'a' | 'b' checks + if(a.size()==0 || b.size()==0) { + pool().set_tag(default_typo_table); // avoid recursion + THROW(0, 0, + typo_table->origin_string(), + "typo table column elements must not be empty"); + } + // overflow check: + // b allowed to be max UNTAINT_TIMES_BIGGER then a + if(b.size()>UNTAINT_TIMES_BIGGER*a.size()) { + pool().set_tag(default_typo_table); // avoid recursion + THROW(0, 0, + &b, + "is %g times longer then '%s', " + "while maximum, handled by Parser, is %d", + ((double)b.size())/a.size(), + a.cstr(), + UNTAINT_TIMES_BIGGER); + } + + // skip 'a' in 'src' + src+=a.size(); + // write 'b' to 'dest' + b.store_to(dest); + dest+=b.size(); + } else + *dest++=*src++; + } while(*src); break; } default: - THROW(0,0, - this, + THROW(0, 0, + this, "unknown untaint language #%d of %d piece", - static_cast(row->item.lang), + static_cast(row->item.lang), i); } row++;