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
@@ -131,128 +131,156 @@ namespace opkele {
 			    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:")