added URI normalization procedure to opkele::util

as specified in RFC3896, section 6

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

1 files changed, 131 insertions, 0 deletions

diff --git a/lib/util.cc b/lib/util.cc
index 26be66a..eacf6d7 100644
--- a/lib/util.cc
+++ b/lib/util.cc
@@ -1,164 +1,295 @@
 #include <errno.h>
 #include <cassert>
+#include <cctype>
 #include <cstring>
 #include <vector>
 #include <string>
+#include <stack>
 #include <openssl/bio.h>
 #include <openssl/evp.h>
 #include <curl/curl.h>
 #include "opkele/util.h"
 #include "opkele/exception.h"
 
 namespace opkele {
     using namespace std;
 
     namespace util {
 
 	/*
 	 * base64
 	 */
 	string encode_base64(const void *data,size_t length) {
 	    BIO *b64 = 0, *bmem = 0;
 	    try {
 		b64 = BIO_new(BIO_f_base64());
 		if(!b64)
 		    throw exception_openssl(OPKELE_CP_ "failed to BIO_new() base64 encoder");
 		BIO_set_flags(b64,BIO_FLAGS_BASE64_NO_NL);
 		bmem = BIO_new(BIO_s_mem());
 		BIO_set_flags(b64,BIO_CLOSE);
 		if(!bmem)
 		    throw exception_openssl(OPKELE_CP_ "failed to BIO_new() memory buffer");
 		BIO_push(b64,bmem);
 		if(((size_t)BIO_write(b64,data,length))!=length)
 		    throw exception_openssl(OPKELE_CP_ "failed to BIO_write()");
 		if(BIO_flush(b64)!=1)
 		    throw exception_openssl(OPKELE_CP_ "failed to BIO_flush()");
 		char *rvd;
 		long rvl = BIO_get_mem_data(bmem,&rvd);
 		string rv(rvd,rvl);
 		BIO_free_all(b64);
 		return rv;
 	    }catch(...) {
 		if(b64) BIO_free_all(b64);
 		throw;
 	    }
 	}
 
 	void decode_base64(const string& data,vector<unsigned char>& rv) {
 	    BIO *b64 = 0, *bmem = 0;
 	    rv.clear();
 	    try {
 		bmem = BIO_new_mem_buf((void*)data.data(),data.size());
 		if(!bmem)
 		    throw exception_openssl(OPKELE_CP_ "failed to BIO_new_mem_buf()");
 		b64 = BIO_new(BIO_f_base64());
 		if(!b64)
 		    throw exception_openssl(OPKELE_CP_ "failed to BIO_new() base64 decoder");
 		BIO_set_flags(b64,BIO_FLAGS_BASE64_NO_NL);
 		BIO_push(b64,bmem);
 		unsigned char tmp[512];
 		size_t rb = 0;
 		while((rb=BIO_read(b64,tmp,sizeof(tmp)))>0)
 		    rv.insert(rv.end(),tmp,&tmp[rb]);
 		BIO_free_all(b64);
 	    }catch(...) {
 		if(b64) BIO_free_all(b64);
 		throw;
 	    }
 	}
 
 	/*
 	 * big numerics
 	 */
 
 	BIGNUM *base64_to_bignum(const string& b64) {
 	    vector<unsigned char> bin;
 	    decode_base64(b64,bin);
 	    BIGNUM *rv = BN_bin2bn(&(bin.front()),bin.size(),0);
 	    if(!rv)
 		throw failed_conversion(OPKELE_CP_ "failed to BN_bin2bn()");
 	    return rv;
 	}
 
 	BIGNUM *dec_to_bignum(const string& dec) {
 	    BIGNUM *rv = 0;
 	    if(!BN_dec2bn(&rv,dec.c_str()))
 		throw failed_conversion(OPKELE_CP_ "failed to BN_dec2bn()");
 	    return rv;
 	}
 
 	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) {
 	    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 )
 		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;
 	}
 
 	/*
 	 *
 	 */
 
 	string url_encode(const string& str) {
 	    char * t = curl_escape(str.c_str(),str.length());
 	    if(!t)
 		throw failed_conversion(OPKELE_CP_ "failed to curl_escape()");
 	    string rv(t);
 	    curl_free(t);
 	    return rv;
 	}
 
 	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 hext 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 colon = uri.find(':');
+	     if(colon==string::npos)
+		 throw bad_input(OPKELE_CP_ "No scheme specified in URI");
+	     transform(
+		     uri.begin(), uri.begin()+colon+1,
+		     back_inserter(rv), ::tolower );
+	     bool s;
+	     if(rv=="http:")
+		 s = false;
+	     else if(rv=="https:")
+		 s = true;
+	     else
+		 throw not_implemented(OPKELE_CP_ "Only http(s) URIs can be normalized here");
+	     string::size_type ul = uri.length();
+	     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");
+	     rv += "//";
+	     string::size_type interesting = uri.find_first_of(":/#?",colon+3);
+	     if(interesting==string::npos) {
+		 transform(
+			 uri.begin()+colon+3,uri.end(),
+			 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[6];
+		     snprintf(tmp,sizeof(tmp),"%d",port);
+		     rv += ':'; rv += tmp;
+		 }
+		 if(ni==string::npos) {
+		     rv += '/'; return rv;
+		 }
+		 interesting = ni;
+	     }else if(ic!='/') {
+		 rv += '/'; rv += ic;
+		 qf = true;
+		 ++interesting;
+	     }
+	     string::size_type n = interesting;
+	     char tmp[3] = { 0,0,0 };
+	     stack<string::size_type> psegs; psegs.push(rv.length());
+	     string pseg;
+	     for(;n<ul;) {
+		 string::size_type unsafe = uri.find_first_of(qf?"%":"%/?#",n);
+		 if(unsafe==string::npos) {
+		     pseg.append(uri,n,ul-n-1); n = ul-1;
+		 }else{
+		     pseg.append(uri,n,unsafe-n);
+		     n = unsafe;
+		 }
+		 char c = uri[n++];
+		 if(c=='%') {
+		     if((n+1)>=ul)
+			 throw bad_input(OPKELE_CP_ "Unexpected end of URI encountered while parsing percent-encoded character");
+		     tmp[0] = uri[n++];
+		     tmp[1] = uri[n++];
+		     if(!( isxdigit(tmp[0]) && isxdigit(tmp[1]) ))
+			 throw bad_input(OPKELE_CP_ "Invalid percent-encoded character in URI being normalized");
+		     int cc = strtol(tmp,0,16);
+		     if( isalpha(cc) || isdigit(cc) || strchr("._~-",cc) )
+			 pseg += cc;
+		     else{
+			 pseg += '%';
+			 pseg += toupper(tmp[0]); pseg += toupper(tmp[1]);
+		     }
+		 }else if(qf) {
+		     rv += pseg; rv += c;
+		     pseg.clear();
+		 }else if(n>=ul || strchr("?/#",c)) {
+		     if(pseg.empty() || pseg==".") {
+		     }else if(pseg=="..") {
+			 if(psegs.size()>1) {
+			     rv.resize(psegs.top()); psegs.pop();
+			 }
+		     }else{
+			 psegs.push(rv.length());
+			 if(c!='/') {
+			     pseg += c;
+			     qf = true;
+			 }
+			 rv += '/'; rv += pseg;
+		     }
+		     if(c=='/' && (n>=ul || strchr("?#",uri[n])) ) {
+			 rv += '/';
+			 if(n<ul)
+			     qf = true;
+		     }else if(strchr("?#",c)) {
+			 if(psegs.size()==1 && psegs.top()==rv.length())
+			     rv += '/';
+			 if(pseg.empty())
+			     rv += c;
+			 qf = true;
+		     }
+		     pseg.clear();
+		 }else{
+		     pseg += c;
+		 }
+	     }
+	     if(!pseg.empty()) {
+		 rv += '/'; rv += pseg;
+	     }
+	     return rv;
+	 }
+
     }
 
 }