aded util::url_decode()

Signed-off-by: Michael Krelin <hacker@klever.net>

1 files changed, 28 insertions, 0 deletions

diff --git a/lib/util.cc b/lib/util.cc
index a6e08e2..3e7f3aa 100644
--- a/lib/util.cc
+++ b/lib/util.cc
@@ -99,192 +99,220 @@ namespace opkele {
         }
 
         string bignum_to_base64(const BIGNUM *bn) {
             vector<unsigned char> bin(BN_num_bytes(bn)+1);
             unsigned char *binptr = &(bin.front())+1;
             int l = BN_bn2bin(bn,binptr);
             if(l && (*binptr)&0x80){
                 (*(--binptr)) = 0; ++l;
             }
             return encode_base64(binptr,l);
         }
 
         /*
          * w3c times
          */
 
         string time_to_w3c(time_t t) {
             struct tm tm_t;
             if(!gmtime_r(&t,&tm_t))
                 throw failed_conversion(OPKELE_CP_ "failed to BN_dec2bn()");
             char rv[25];
             if(!strftime(rv,sizeof(rv)-1,"%Y-%m-%dT%H:%M:%SZ",&tm_t))
                 throw failed_conversion(OPKELE_CP_ "failed to strftime()");
             return rv;
         }
 
         time_t w3c_to_time(const string& w) {
             int fraction;
             struct tm tm_t;
             memset(&tm_t,0,sizeof(tm_t));
             if( (
                         sscanf(
                             w.c_str(),
                             "%04d-%02d-%02dT%02d:%02d:%02dZ",
                             &tm_t.tm_year,&tm_t.tm_mon,&tm_t.tm_mday,
                             &tm_t.tm_hour,&tm_t.tm_min,&tm_t.tm_sec
                             ) != 6
                 ) && (
                     sscanf(
                         w.c_str(),
                         "%04d-%02d-%02dT%02d:%02d:%02d.%03dZ",
                         &tm_t.tm_year,&tm_t.tm_mon,&tm_t.tm_mday,
                         &tm_t.tm_hour,&tm_t.tm_min,&tm_t.tm_sec,
                         &fraction
                         ) != 7
                     ) )
                 throw failed_conversion(OPKELE_CP_ "failed to sscanf()");
             tm_t.tm_mon--;
             tm_t.tm_year-=1900;
             time_t rv = mktime(&tm_t);
             if(rv==(time_t)-1)
                 throw failed_conversion(OPKELE_CP_ "failed to mktime()");
             return rv-timezone;
         }
 
         /*
          *
          */
 
         static inline bool isrfc3986unreserved(int c) {
             if(c<'-') return false;
             if(c<='.') return true;
             if(c<'0') return false; if(c<='9') return true;
             if(c<'A') return false; if(c<='Z') return true;
             if(c<'_') return false;
             if(c=='_') return true;
             if(c<'a') return false; if(c<='z') return true;
             if(c=='~') return true;
             return false;
         }
 
         struct __url_encoder : public unary_function<char,void> {
             public:
                 string& rv;
 
                 __url_encoder(string& r) : rv(r) { }
 
                 result_type operator()(argument_type c) {
                     if(isrfc3986unreserved(c))
                         rv += c;
                     else{
                         char tmp[4];
                         snprintf(tmp,sizeof(tmp),"%%%02X",
                                 (c&0xff));
                         rv += tmp;
                     }
                 }
         };
 
         string url_encode(const string& str) {
             string rv;
             for_each(str.begin(),str.end(),
                     __url_encoder(rv));
             return rv;
         }
 
+        string url_decode(const string& str) {
+            string rv;
+            back_insert_iterator<string> ii(rv);
+            for(string::const_iterator i=str.begin(),ie=str.end();
+                    i!=ie;++i) {
+                switch(*i) {
+                    case '+':
+                        *(ii++) = ' '; break;
+                    case '%':
+                        ++i;
+                        static char tmp[3] = {0,0,0};
+                        if(i==ie)
+                            throw failed_conversion(OPKELE_CP_ "trailing percent in the url-encoded string");
+                        tmp[0] == *(i++);
+                        if(i==ie)
+                            throw failed_conversion(OPKELE_CP_ "not enough hexadecimals after the percent sign in url-encoded string");
+                        tmp[1] == *i;
+                        if(!(isxdigit(tmp[0]) && isxdigit(tmp[1])))
+                            throw failed_conversion(OPKELE_CP_ "non-hex follows percent in url-encoded string");
+                        *(ii++) = strtol(tmp,0,16);
+                        break;
+                    default:
+                        *(ii++) = *i; break;
+                }
+            }
+            return rv;
+        }
+
         string attr_escape(const string& str) {
             static const char *unsafechars = "<>&\n\"'";
             string rv;
             string::size_type p=0;
             while(true) {
                 string::size_type us = str.find_first_of(unsafechars,p);
                 if(us==string::npos) {
                     if(p!=str.length())
                         rv.append(str,p,str.length()-p);
                     return rv;
                 }
                 rv.append(str,p,us-p);
                 rv += "&#";
                 rv += long_to_string((long)str[us]);
                 rv += ';';
                 p = us+1;
             }
         }
 
         string long_to_string(long l) {
             char rv[32];
             int r=snprintf(rv,sizeof(rv),"%ld",l);
             if(r<0 || r>=(int)sizeof(rv))
                 throw failed_conversion(OPKELE_CP_ "failed to snprintf()");
             return rv;
         }
 
         long string_to_long(const string& s) {
             char *endptr = 0;
             long rv = strtol(s.c_str(),&endptr,10);
             if((!endptr) || endptr==s.c_str())
                 throw failed_conversion(OPKELE_CP_ "failed to strtol()");
             return rv;
         }
 
         /*
          * Normalize URL according to the rules, described in rfc 3986, section 6
          *
          * - uppercase hex triplets (e.g. %ab -> %AB)
          * - lowercase scheme and host
          * - decode %-encoded characters, specified as unreserved in rfc 3986, section 2.3,
          *   that is - [:alpha:][:digit:]._~-
          * - remove dot segments
          * - remove empty and default ports
          * - if there's no path component, add '/'
          */
          string rfc_3986_normalize_uri(const string& uri) {
              string rv;
              string::size_type ns = uri.find_first_not_of(data::_whitespace_chars);
              if(ns==string::npos)
                  throw bad_input(OPKELE_CP_ "Can't normalize empty URI");
              string::size_type colon = uri.find(':',ns);
              if(colon==string::npos)
                  throw bad_input(OPKELE_CP_ "No scheme specified in URI");
              transform(
                      uri.begin()+ns, uri.begin()+colon+1,
                      back_inserter(rv), ::tolower );
              bool s;
              string::size_type ul = uri.find_last_not_of(data::_whitespace_chars)+1;
              if(ul <= (colon+3))
                  throw bad_input(OPKELE_CP_ "Unexpected end of URI being normalized encountered");
              if(uri[colon+1]!='/' || uri[colon+2]!='/')
                  throw bad_input(OPKELE_CP_ "Unexpected input in URI being normalized after scheme component");
              if(rv=="http:")
                  s = false;
              else if(rv=="https:")
                  s = true;
              else{
                  /* TODO: support more schemes.  e.g. xri. How do we normalize
                   * xri?
                   */
                  rv.append(uri,colon+1,ul-colon-1);
                  return rv;
              }
              rv += "//";
              string::size_type interesting = uri.find_first_of(":/#?",colon+3);
              if(interesting==string::npos) {
                  transform(
                          uri.begin()+colon+3,uri.begin()+ul,
                          back_inserter(rv), ::tolower );
                  rv += '/'; return rv;
              }
              transform(
                      uri.begin()+colon+3,uri.begin()+interesting,
                      back_inserter(rv), ::tolower );
              bool qf = false;
              char ic = uri[interesting];
              if(ic==':') {
                  string::size_type ni = uri.find_first_of("/#?%",interesting+1);
                  const char *nptr = uri.data()+interesting+1;
                  char *eptr = 0;
                  long port = strtol(nptr,&eptr,10);
                  if( (port>0) && (port<65535) && port!=(s?443:80) ) {
                      char tmp[8];
                      snprintf(tmp,sizeof(tmp),":%ld",port);
                      rv += tmp;