Implement urlencode and urldecode

4 files changed, 57 insertions, 6 deletions

diff --git a/src/hex.h b/src/hex.h
index 87a6aecb4..6f00a79bf 100644
--- a/src/hex.h
+++ b/src/hex.h
@@ -46,4 +46,17 @@ static inline std::string hex_encode(const std::string &data)
     return hex_encode(data.c_str(), data.size());
 }
 
+static inline bool hex_digit_decode(char hexdigit, unsigned char &value)
+{
+	if(hexdigit >= '0' && hexdigit <= '9')
+		value = hexdigit - '0';
+	else if(hexdigit >= 'A' && hexdigit <= 'F')
+		value = hexdigit - 'A' + 10;
+	else if(hexdigit >= 'a' && hexdigit <= 'f')
+		value = hexdigit - 'a' + 10;
+	else
+		return false;
+	return true;
+}
+
 #endif
diff --git a/src/test.cpp b/src/test.cpp
index 5e025f2f5..c969c0951 100644
--- a/src/test.cpp
+++ b/src/test.cpp
@@ -171,6 +171,10 @@ struct TestUtilities: public TestBase
 		UASSERT(removeStringEnd("bc", ends) == "b");
 		UASSERT(removeStringEnd("12c", ends) == "12");
 		UASSERT(removeStringEnd("foo", ends) == "");
+		UASSERT(urlencode("\"Aardvarks lurk, OK?\"")
+				== "%22Aardvarks%20lurk%2C%20OK%3F%22");
+		UASSERT(urldecode("%22Aardvarks%20lurk%2C%20OK%3F%22")
+				== "\"Aardvarks lurk, OK?\"");
 	}
 };
 
diff --git a/src/util/string.cpp b/src/util/string.cpp
index 39a14598b..925d0ea35 100644
--- a/src/util/string.cpp
+++ b/src/util/string.cpp
@@ -21,8 +21,12 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "pointer.h"
 #include "numeric.h"
 
+#include <sstream>
+#include <iomanip>
+
 #include "../sha1.h"
 #include "../base64.h"
+#include "../hex.h"
 #include "../porting.h"
 
 std::wstring narrow_to_wide(const std::string& mbs)
@@ -68,11 +72,40 @@ std::string translatePassword(std::string playername, std::wstring password)
 	return pwd;
 }
 
-size_t curl_write_data(char *ptr, size_t size, size_t nmemb, void *userdata) {
-    std::ostringstream *stream = (std::ostringstream*)userdata;
-    size_t count = size * nmemb;
-    stream->write(ptr, count);
-    return count;
+std::string urlencode(std::string str)
+{
+	// Encodes non-unreserved URI characters by a percent sign
+	// followed by two hex digits. See RFC 3986, section 2.3.
+	static const char url_hex_chars[] = "0123456789ABCDEF";
+	std::ostringstream oss(std::ios::binary);
+	for (u32 i = 0; i < str.size(); i++) {
+		unsigned char c = str[i];
+		if (isalnum(c) || c == '-' || c == '.' || c == '_' || c == '~')
+			oss << c;
+		else
+			oss << "%"
+				<< url_hex_chars[(c & 0xf0) >> 4]
+				<< url_hex_chars[c & 0x0f];
+	}
+	return oss.str();
+}
+
+std::string urldecode(std::string str)
+{
+	// Inverse of urlencode
+	std::ostringstream oss(std::ios::binary);
+	for (u32 i = 0; i < str.size(); i++) {
+		unsigned char highvalue, lowvalue;
+		if (str[i] == '%' &&
+				hex_digit_decode(str[i+1], highvalue) &&
+				hex_digit_decode(str[i+2], lowvalue)) {
+			oss << (char) ((highvalue << 4) | lowvalue);
+			i += 2;
+		}
+		else
+			oss << str[i];
+	}
+	return oss.str();
 }
 
 u32 readFlagString(std::string str, FlagDesc *flagdesc) {
diff --git a/src/util/string.h b/src/util/string.h
index 81855962f..e5a60bc47 100644
--- a/src/util/string.h
+++ b/src/util/string.h
@@ -317,7 +317,8 @@ inline std::string unescape_string(std::string &s)
 }
 
 std::string translatePassword(std::string playername, std::wstring password);
-size_t curl_write_data(char *ptr, size_t size, size_t nmemb, void *userdata);
+std::string urlencode(std::string str);
+std::string urldecode(std::string str);
 u32 readFlagString(std::string str, FlagDesc *flagdesc);
 std::string writeFlagString(u32 flags, FlagDesc *flagdesc);
 char *mystrtok_r(char *s, const char *sep, char **lasts);