--- parser3/src/main/untaint.C 2001/03/12 13:40:27 1.1 +++ parser3/src/main/untaint.C 2001/03/25 09:01:00 1.16 @@ -1,45 +1,86 @@ -/* - Parser - Copyright (c) 2001 ArtLebedev Group (http://www.artlebedev.com) - Author: Alexander Petrosyan (http://design.ru/paf) +/** @file + Parser: String class part: untaint mechanizm. - $Id: untaint.C,v 1.1 2001/03/12 13:40:27 paf Exp $ + Copyright(c) 2001 ArtLebedev Group(http://www.artlebedev.com) + + Author: Alexander Petrosyan (http://design.ru/paf) + + $Id: untaint.C,v 1.16 2001/03/25 09:01:00 paf Exp $ */ -#include +#include "pa_config_includes.h" #include "pa_pool.h" #include "pa_string.h" #include "pa_hash.h" #include "pa_exception.h" +#include "pa_table.h" #define escape(cases) \ { \ - const char *ptr=row->item.ptr; \ - int size=row->item.size; \ - for (;*ptr;ptr++) \ - switch(*ptr) { \ + const char *src=row->item.ptr; \ + for(int size=row->item.size; size--; src++) \ + switch(*src) { \ cases \ - default: *copy_here++=*ptr; break; \ } \ } -#define escape_value(a, c) case a: *copy_here++=c; break; -#define escape_subst(a, b, bsize) \ - case a: \ - { \ - strncpy(copy_here, b, bsize); \ - copy_here+=bsize; \ - } \ - break; +#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)) { \ + static const char *hex="0123456789ABCDEF"; \ + char chunk[3]={prefix}; \ + chunk[1]=hex[((unsigned char)*src)/0x10]; \ + chunk[2]=hex[((unsigned char)*src)%0x10]; \ + strncpy(dest, chunk, 3); dest+=3; \ + } else \ + *dest++=*src; \ + break + +inline bool need_file_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_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_header_encode(unsigned char c){ + if(strchr(" ,:", c)) + return false; + + return need_uri_encode(c); +} // String -char *String::cstr() const { - char *result=static_cast(malloc(size()*UNTAINT_TIMES_BIGGER+1)); +static bool typo_present(Array::Item *value, const void *info) { + Array *row=static_cast(value); + const char *src=static_cast(info); + + int partial; + row->get_string(0)->cmp(src, partial); + return + partial==0 || // full match + partial==1; // typo left column starts 'src' +} + +/// @todo optimize whitespaces for all but 'html' +char *String::store_to(char *dest) const { + // $MAIN:html-typo table + Table *typo_table=static_cast(pool().tag()); - char *copy_here=result; const Chunk *chunk=&head; - // TODO: оптимизировать whitespaces для всех, кроме 'html' do { const Chunk::Row *row=chunk->rows; for(int i=0; icount; i++) { @@ -49,60 +90,140 @@ char *String::cstr() const { // WARNING: // string can grow only UNTAINT_TIMES_BIGGER switch(row->item.lang) { - case NO: + case UL_NO: // clean piece - case YES: + case UL_YES: // tainted piece, but undefined untaint language // for VString.get_double of tainted values // for ^process{body} evaluation - case AS_IS: + case UL_AS_IS: // tainted, untaint language: as-is - memcpy(copy_here, row->item.ptr, row->item.size); - copy_here+=row->item.size; + memcpy(dest, row->item.ptr, row->item.size); + dest+=row->item.size; break; - case TABLE: + case UL_FILE_NAME: + // tainted, untaint language: file [name] escape( - escape_value('\t', ' ') - escape_value('\n', ' ') + to_char(' ', '_'); + encode(need_file_encode, '-'); ); break; - case SQL: + case UL_URI: + // tainted, untaint language: uri + escape( + to_char(' ', '+'); + encode(need_uri_encode, '%'); + ); + break; + case UL_HEADER: + // tainted, untaint language: header + escape( + encode(need_header_encode, '%'); + ); + break; + case UL_TABLE: + // tainted, untaint language: table + escape( + to_char('\t', ' '); + to_char('\n', ' '); + _default; + ); + break; + case UL_SQL: // tainted, untaint language: sql // TODO: зависимость от sql сервера - memset(copy_here, '?', row->item.size); - copy_here+=row->item.size; + memset(dest, '?', row->item.size); + dest+=row->item.size; break; - case JS: + case UL_JS: escape( - escape_subst('"', "\\\"", 2) - escape_subst('\'', "\\'", 2) - escape_subst('\n', "\\n", 2) - escape_subst('\r', "\\r", 2) - escape_subst('\\', "\\\\", 2) - escape_subst('я', "\\я", 2) + to_string('"', "\\\"", 2); + to_string('\'', "\\'", 2); + to_string('\n', "\\n", 2); + to_string('\\', "\\\\", 2); + to_string('\xFF', "\\\xFF", 2); + _default; ); break; - case HTML: + case UL_HTML: escape( - escape_subst('&', "&", 5) // BEFORE consequent relpaces yelding '&' - escape_subst('>', ">", 4) - escape_subst('<', "<",4) - escape_subst('"', """,6) - escape_value('\t', ' ') - //TODO: XSLT escape_subst('\'', "'", 6) + to_string('&', "&", 5); + to_string('>', ">", 4); + to_string('<', "<",4); + to_string('"', """,6); + to_char('\t', ' '); + //TODO: XSLT to_string('\'', "'", 6) + _default; ); break; - case HTML_TYPO: + case UL_HTML_TYPO: { // tainted, untaint language: html-typo - escape( - escape_subst('&', "&", 5) // BEFORE consequent relpaces yelding '&' - escape_subst('>', ">", 4) - escape_subst('<', "<",4) - escape_subst('"', """,6) - escape_value('\t', ' ') - //TODO: $MAIN:html-type table replace, max length(b)==UNTAINT_TIMES_BIGGER*length(a) - ); + char *html=(char *)malloc(size()*6/*""" the longest possible*/+1); + size_t html_size; + { // local dest + char *dest=html; + escape( + to_string('&', "&", 5); + to_string('>', ">", 4); + to_string('<', "<",4); + to_string('"', """,6); + to_char('\t', ' '); + // convinient name for typo match "\n" + case '\r': + *dest++='\\'; *dest++='n'; // \r -> \n + if(src[1]=='\n') // \r\n -> remove \n + src++; + break; + to_string('\n', "\\n", 2); + //TODO: XSLT to_string('\'', "'", 6) + _default; + ); + *dest=0; + html_size=dest-html; + } + // 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; + } break; + } default: THROW(0,0, this, @@ -115,6 +236,5 @@ char *String::cstr() const { chunk=row->link; } while(chunk); break2: - *copy_here=0; - return result; + return dest; }