I am working on a client for a RESTful service, using .NET Core 2.0. The remote service returns challenges like this:
WwwAuthenticate: Bearer realm="https://somesite/auth",service="some site",scope="some scope"
Which need to get turned into token requests like:
GET https://somesite/auth?service=some%20site&scope=some%20scope
Parsing the header to get a scheme and parameter is easy with AuthenticationHeaderValue, but that just gets me the realm="https://somesite/auth",service="some site",scope="some scope" string. How can I easily and reliably parse this to the individual realm, service, and scope components? It's not quite JSON, so deserializing it with NewtonSoft JsonConvert won't work. I could regex it into something that looks like XML or JSON, but that seems incredibly hacky (not to mention unreliable).
Surely there's a better way?
Since I don't see a non-hacky way. Maybe this hacky way may help
string input = #"WwwAuthenticate: Bearer realm=""https://somesite/auth"",service=""some site"",scope=""some, scope""";
var dict = Regex.Matches(input, #"[\W]+(\w+)=""(.+?)""").Cast<Match>()
.ToDictionary(x => x.Groups[1].Value, x => x.Groups[2].Value);
var url = dict["realm"] + "?" + string.Join("&", dict.Where(x => x.Key != "realm").Select(x => x.Key + "=" + WebUtility.UrlEncode(x.Value)));
OUTPUT
url => https://somesite/auth?service=some+site&scope=some%2C+scope
BTW: I added a , in "scope"
Possible duplicate of How to parse values from Www-Authenticate
Using the schema defined in RFC6750 and RFC2616, a slightly more precise parser implementation is included below. This parser takes into account the possibility that strings might contain =, ,, and/or escaped ".
internal class AuthParamParser
{
private string _buffer;
private int _i;
private AuthParamParser(string param)
{
_buffer = param;
_i = 0;
}
public static Dictionary<string, string> Parse(string param)
{
var state = new AuthParamParser(param);
var result = new Dictionary<string, string>();
var token = state.ReadToken();
while (!string.IsNullOrEmpty(token))
{
if (!state.ReadDelim('='))
return result;
result.Add(token, state.ReadString());
if (!state.ReadDelim(','))
return result;
token = state.ReadToken();
}
return result;
}
private string ReadToken()
{
var start = _i;
while (_i < _buffer.Length && ValidTokenChar(_buffer[_i]))
_i++;
return _buffer.Substring(start, _i - start);
}
private bool ReadDelim(char ch)
{
while (_i < _buffer.Length && char.IsWhiteSpace(_buffer[_i]))
_i++;
if (_i >= _buffer.Length || _buffer[_i] != ch)
return false;
_i++;
while (_i < _buffer.Length && char.IsWhiteSpace(_buffer[_i]))
_i++;
return true;
}
private string ReadString()
{
if (_i < _buffer.Length && _buffer[_i] == '"')
{
var buffer = new StringBuilder();
_i++;
while (_i < _buffer.Length)
{
if (_buffer[_i] == '\\' && (_i + 1) < _buffer.Length)
{
_i++;
buffer.Append(_buffer[_i]);
_i++;
}
else if (_buffer[_i] == '"')
{
_i++;
return buffer.ToString();
}
else
{
buffer.Append(_buffer[_i]);
_i++;
}
}
return buffer.ToString();
}
else
{
return ReadToken();
}
}
private bool ValidTokenChar(char ch)
{
if (ch < 32)
return false;
if (ch == '(' || ch == ')' || ch == '<' || ch == '>' || ch == '#'
|| ch == ',' || ch == ';' || ch == ':' || ch == '\\' || ch == '"'
|| ch == '/' || ch == '[' || ch == ']' || ch == '?' || ch == '='
|| ch == '{' || ch == '}' || ch == 127 || ch == ' ' || ch == '\t')
return false;
return true;
}
}
Related
I'm trying to make a program in C# to decide weather Brackets are balanced or not..
After some work i made it using Array Stack and it's working but i have 2 problems:
1) if i entered brackets like this way "()[]{}(())" it shall work
i.e ("I must start with only ( [ {") but if i started the string
with ("})]") it will always says unbalanced even if it was... so I'm
asking if someone could give me a hint for solution.
2) Is there a better way for Pop method cause the else condition is
just annoying me and if i removed it, it will no longer work
Program.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace Balanced_Brackets
{
class Program
{
public static bool IsBalanced(string brackets)
{
bool balanced = false;
MyStack s = new MyStack();
foreach (var item in brackets)
{
if (item == '(' || item == '[' || item == '{')
s.Push(item);
else if (item == ')' || item == ']' || item == '}')
{
var poped = s.Pop();
if (poped == '(' && item == ')')
balanced = true;
else if (poped == '[' && item == ']')
balanced = true;
else if (poped == '{' && item == '}')
balanced = true;
else
return balanced = false;
}
}
if (balanced == true)
return true;
else
return false;
}
static void Main(string[] args)
{
string Brackets = Console.ReadLine();
IsBalanced(Brackets);
if (IsBalanced(Brackets))
Console.Write("Balanced");
else
Console.Write("Un-Balanced");
Console.ReadKey();
}
}
class MyStack
{
char[] exp = new char[5];
public int top = -1;
public bool IsEmpty()
{
return (top == -1);
}
public bool IsFull()
{
return (top == exp.Length - 1);
}
public void Push(char a)
{
if (!IsFull())
exp[++top] = a;
}
public char Pop()
{
if (!IsEmpty())
return exp[top--];
else
return ' ';
}
}
}
Before I start: Yes, I have checked the other questions and answers on this topic both here and elsewhere.
I have found an example string that the .Net will base64 decode even though it isn't actually base64 encoded. Here is the example:
Rhinocort Aqueous 64mcg/dose Nasal Spray
The .Net method Convert.FromBase64String does not throw an exception when decoding this string so my IsBase64Encoded method happily returns true for this string.
Interestingly, if I use the cygwin base64 -d command using this string as input, it fails with the message invalid input.
Even more interestingly, the source that I thought that belongs to this executable (http://libb64.sourceforge.net/) "decodes" this same string with the same result as I am getting from the .Net Convert.FromBase64String. I will keep looking hoping to find a clue elsewhere but right now I'm stumped.
Any ideas?
There's a slightly better solution which also checks the input string length.
I recommend you do a check at the beginning. If the input is null or empty then return false.
http://www.codeproject.com/Questions/177808/How-to-determine-if-a-string-is-Base-decoded-or
When strings do pass Base64 decoding and the decoded data has special characters, then perhaps we can conclude that it was not valid Base64 (this depends on the encoding). Also, sometimes we're expecting the data being passed to be Base64, but sometimes it may not be properly padded with '='. Therefore, one method uses "strict" rules for Base64 and the other is "forgiving".
[TestMethod]
public void CheckForBase64()
{
Assert.IsFalse(IsBase64DataStrict("eyJhIjoiMSIsImIiOiI2N2NiZjA5MC00ZGRiLTQ3OTktOTlmZi1hMjhhYmUyNzQwYjEiLCJmIjoiMSIsImciOiIxIn0"));
Assert.IsTrue(IsBase64DataForgiving("eyJhIjoiMSIsImIiOiI2N2NiZjA5MC00ZGRiLTQ3OTktOTlmZi1hMjhhYmUyNzQwYjEiLCJmIjoiMSIsImciOiIxIn0"));
Assert.IsFalse(IsBase64DataForgiving("testing123"));
Assert.IsFalse(IsBase64DataStrict("ABBA"));
Assert.IsFalse(IsBase64DataForgiving("6AC648C9-C08F-4F9D-A0A5-3904CF15ED3E"));
}
public bool IsBase64DataStrict(string data)
{
if (string.IsNullOrWhiteSpace(data)) return false;
if ((new Regex(#"[^A-Z0-9+\/=]", RegexOptions.IgnoreCase)).IsMatch(data)) return false;
if (data.Length % 4 != 0) return false;
var e = data.IndexOf('=');
var l = data.Length;
if (!(e == -1 || e == l - 1 || (e == l - 2 && data[l - 1] == '='))) return false;
var decoded = string.Empty;
try
{
byte[] decodedData = Convert.FromBase64String(data);
decoded = Encoding.UTF8.GetString(decodedData);
}
catch(Exception)
{
return false;
}
//check for special chars that you know should not be there
char current;
for (int i = 0; i < decoded.Length; i++)
{
current = decoded[i];
if (current == 65533) return false;
if (!((current == 0x9 || current == 0xA || current == 0xD) ||
((current >= 0x20) && (current <= 0xD7FF)) ||
((current >= 0xE000) && (current <= 0xFFFD)) ||
((current >= 0x10000) && (current <= 0x10FFFF))))
{
return false;
}
}
return true;
}
public bool IsBase64DataForgiving(string data)
{
if (string.IsNullOrWhiteSpace(data)) return false;
//it could be made more forgiving by replacing any spaces with '+' here
if ((new Regex(#"[^A-Z0-9+\/=]", RegexOptions.IgnoreCase)).IsMatch(data)) return false;
//this is the forgiving part
if (data.Length % 4 > 0)
data = data.PadRight(data.Length + 4 - data.Length % 4, '=');
var e = data.IndexOf('=');
var l = data.Length;
if (!(e == -1 || e == l - 1 || (e == l - 2 && data[l - 1] == '='))) return false;
var decoded = string.Empty;
try
{
byte[] decodedData = Convert.FromBase64String(data);
decoded = Encoding.UTF8.GetString(decodedData);
}
catch (Exception)
{
return false;
}
//check for special chars that you know should not be there
char current;
for (int i = 0; i < decoded.Length; i++)
{
current = decoded[i];
if (current == 65533) return false;
if (!((current == 0x9 || current == 0xA || current == 0xD) ||
((current >= 0x20) && (current <= 0xD7FF)) ||
((current >= 0xE000) && (current <= 0xFFFD)) ||
((current >= 0x10000) && (current <= 0x10FFFF))))
{
return false;
}
}
return true;
}
since my prof won't let me use RegEx, I'm stuck with using loops to check each character on a string.
Does anyone have a sample code/algorithm?
public void setAddress(string strAddress)
{
do
{
foreach (char c in Name)
{
if ( /*check for characters*/ == false)
{
Address = strAddress;
}
}
if ( /*check for characters*/ == true)
{
Console.Write("Invalid!");
}
} while ( /*check for characters*/ == true)
}
public int getAddress()
{
return Address;
}
I need to only include letters and numbers. Characters such as !##$%^& are not allowed.
I'm not allowed to use RegEx because he hasn't taught that to us yet... well I couldn't attend class on the day he taught these loops and character checking, so now he won't tell me more. ANYWAY, if there's a more efficient way without using RegEx, that'd be helpful.
string s = #"$KUH% I*$)OFNlkfn$";
var withoutSpecial = new string(s.Where(c => Char.IsLetterOrDigit(c)
|| Char.IsWhiteSpace(c)).ToArray());
if (s != withoutSpecial)
{
Console.WriteLine("String contains special chars");
}
You can do it without loops at all :)
Source: https://stackoverflow.com/a/4503614/1714342
EDIT:
if(s.Any(c=>c => !Char.IsLetterOrDigit(c) || !Char.IsWhiteSpace(c))
{
Console.WriteLine("String contains special chars");
}
You may not need loops at all, just character checking will do:
if (Name.IndexofAny("!##$%^&*()".ToCharArray() != -1))
Console.WriteLine("Valid Address");
else
Console.WriteLine("Invalid Address");
See http://msdn.microsoft.com/en-us/library/system.string.indexofany.aspx
A solution with explicit loop could be
String s = #"$KUH% I*$)OFNlkfn$";
foreach (Char c in s)
if (!(Char.IsLetterOrDigit(c) || Char.IsWhiteSpace(c))) {
Console.WriteLine("String contains special chars");
break;
}
bool check_for_characters(char c)
{
return (c >= '0' && c <= '9') || (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z');
}
I get the way to create space "ThisCourse" to be "This Course"
Add Space Before Capital Letter By (EtienneT) LINQ Statement
But i cannot
Create Space Betweeen This "ThisCourseID" to be "This Course ID" without space between "ID"
And Is there a way to do this in Linq ??
Well, if it has to be a single linq statement...
var s = "ThisCourseIDMoreXYeahY";
s = string.Join(
string.Empty,
s.Select((x,i) => (
char.IsUpper(x) && i>0 &&
( char.IsLower(s[i-1]) || (i<s.Count()-1 && char.IsLower(s[i+1])) )
) ? " " + x : x.ToString()));
Console.WriteLine(s);
Output: "This Course ID More X Yeah Y"
var s = "ThisCourseID";
for (var i = 1; i < s.Length; i++)
{
if (char.IsLower(s[i - 1]) && char.IsUpper(s[i]))
{
s = s.Insert(i, " ");
}
}
Console.WriteLine(s); // "This Course ID"
You can improve this using StringBuilder if you are going to use this on very long strings, but for your purpose, as you presented it, it should work just fine.
FIX:
var s = "ThisCourseIDSomething";
for (var i = 1; i < s.Length - 1; i++)
{
if (char.IsLower(s[i - 1]) && char.IsUpper(s[i]) ||
s[i - 1] != ' ' && char.IsUpper(s[i]) && char.IsLower(s[i + 1]))
{
s = s.Insert(i, " ");
}
}
Console.WriteLine(s); // This Course ID Something
You don't need LINQ - but you could 'enumerate' and use lambda to make it more generic...
(though not sure if any of this makes sense)
static IEnumerable<string> Split(this string text, Func<char?, char?, char, int?> shouldSplit)
{
StringBuilder output = new StringBuilder();
char? before = null;
char? before2nd = null;
foreach (var c in text)
{
var where = shouldSplit(before2nd, before, c);
if (where != null)
{
var str = output.ToString();
switch(where)
{
case -1:
output.Remove(0, str.Length -1);
yield return str.Substring(0, str.Length - 1);
break;
case 0: default:
output.Clear();
yield return str;
break;
}
}
output.Append(c);
before2nd = before;
before = c;
}
yield return output.ToString();
}
...and call it like this e.g. ...
static IEnumerable<string> SplitLines(this string text)
{
return text.Split((before2nd, before, now) =>
{
if ((before2nd ?? 'A') == '\r' && (before ?? 'A') == '\n') return 0; // split on 'now'
return null; // don't split
});
}
static IEnumerable<string> SplitOnCase(this string text)
{
return text.Split((before2nd, before, now) =>
{
if (char.IsLower(before ?? 'A') && char.IsUpper(now)) return 0; // split on 'now'
if (char.IsUpper(before2nd ?? 'a') && char.IsUpper(before ?? 'a') && char.IsLower(now)) return -1; // split one char before
return null; // don't split
});
}
...and somewhere...
var text = "ToSplitOrNotToSplitTHEQuestionIsNow";
var words = text.SplitOnCase();
foreach (var word in words)
Console.WriteLine(word);
text = "To\r\nSplit\r\nOr\r\nNot\r\nTo\r\nSplit\r\nTHE\r\nQuestion\r\nIs\r\nNow";
words = text.SplitLines();
foreach (var word in words)
Console.WriteLine(word);
:)
I'm looking for a fast .NET class/library that has a StringComparer that supports wildcard (*) AND incase-sensitivity.
Any Ideas?
You could use Regex with RegexOptions.IgnoreCase, then compare with the IsMatch method.
var wordRegex = new Regex( "^" + prefix + ".*" + suffix + "$", RegexOptions.IgnoreCase );
if (wordRegex.IsMatch( testWord ))
{
...
}
This would match prefix*suffix. You might also consider using StartsWith or EndsWith as alternatives.
Alternatively you can use these extended functions:
public static bool CompareWildcards(this string WildString, string Mask, bool IgnoreCase)
{
int i = 0;
if (String.IsNullOrEmpty(Mask))
return false;
if (Mask == "*")
return true;
while (i != Mask.Length)
{
if (CompareWildcard(WildString, Mask.Substring(i), IgnoreCase))
return true;
while (i != Mask.Length && Mask[i] != ';')
i += 1;
if (i != Mask.Length && Mask[i] == ';')
{
i += 1;
while (i != Mask.Length && Mask[i] == ' ')
i += 1;
}
}
return false;
}
public static bool CompareWildcard(this string WildString, string Mask, bool IgnoreCase)
{
int i = 0, k = 0;
while (k != WildString.Length)
{
if (i > Mask.Length - 1)
return false;
switch (Mask[i])
{
case '*':
if ((i + 1) == Mask.Length)
return true;
while (k != WildString.Length)
{
if (CompareWildcard(WildString.Substring(k + 1), Mask.Substring(i + 1), IgnoreCase))
return true;
k += 1;
}
return false;
case '?':
break;
default:
if (IgnoreCase == false && WildString[k] != Mask[i])
return false;
if (IgnoreCase && Char.ToLower(WildString[k]) != Char.ToLower(Mask[i]))
return false;
break;
}
i += 1;
k += 1;
}
if (k == WildString.Length)
{
if (i == Mask.Length || Mask[i] == ';' || Mask[i] == '*')
return true;
}
return false;
}
CompareWildcards compares a string against multiple wildcard patterns, and CompareWildcard compares a string against a single wildcard pattern.
Example usage:
if (Path.CompareWildcards("*txt;*.zip;", true) == true)
{
// Path matches wildcard
}
alternatively you can try following
class Wildcard : Regex
{
public Wildcard() { }
public Wildcard(string pattern) : base(WildcardToRegex(pattern)) { }
public Wildcard(string pattern, RegexOptions options) : base(WildcardToRegex(pattern), options) { }
public static string WildcardToRegex(string pattern)
{
return "^" + Regex.Escape(pattern).
Replace("\\*", ".*").
Replace("\\?", ".") + "$";
}
}