System.Net.Http.Headers.AuthenticationHeaderParser Class

Provides static methods for parsing AuthenticationHeaderValue objects from strings.

Overview

The AuthenticationHeaderParser class is a utility class that provides functionality to parse strings into AuthenticationHeaderValue objects. This is particularly useful when processing HTTP headers that contain authentication information, such as the Authorization header.

It offers methods to convert a string representation of an authentication header into a structured object, making it easier to work with the scheme and parameters of the authentication.

Members

Methods

Name	Description
`Parse(string value)`	Parses a string into an `AuthenticationHeaderValue` object.
`TryParse(string value, out AuthenticationHeaderValue parsedValue)`	Attempts to parse a string into an `AuthenticationHeaderValue` object without throwing an exception if parsing fails.

Remarks

When dealing with HTTP communication, the Authorization header is crucial for authentication. The AuthenticationHeaderParser class simplifies the process of extracting and interpreting the components of this header. For example, it can distinguish between the authentication scheme (e.g., "Basic", "Bearer") and the associated credentials or token.

The Parse method is convenient for scenarios where you expect the input string to be valid. If the string is malformed, it will throw a FormatException.

The TryParse method provides a more robust approach, returning a boolean indicating success and providing the parsed value through an output parameter. This is ideal for situations where the input might be unreliable or when you want to handle parsing errors gracefully.

Note

The AuthenticationHeaderValue class itself holds the parsed scheme and parameters. AuthenticationHeaderParser is the mechanism to obtain an instance of AuthenticationHeaderValue from a raw string.

Examples

Example 1: Using `Parse`

This example demonstrates how to use the Parse method to create an AuthenticationHeaderValue object from a Basic authentication string.


using System.Net.Http.Headers;

string headerString = "Basic YWxhZGRpbjpvcGVuc2VzYW1l";
AuthenticationHeaderValue authHeader = AuthenticationHeaderParser.Parse(headerString);

// authHeader.Scheme will be "Basic"
// authHeader.Parameter will be "YWxhZGRpbjpvcGVuc2VzYW1l"

Example 2: Using `TryParse`

This example shows how to use the TryParse method to safely parse a Bearer token string.


using System.Net.Http.Headers;

string headerString = "Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...";
AuthenticationHeaderValue parsedValue;

if (AuthenticationHeaderParser.TryParse(headerString, out parsedValue))
{
    // Parsing succeeded
    // parsedValue.Scheme will be "Bearer"
    // parsedValue.Parameter will be "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9..."
    Console.WriteLine($"Scheme: {parsedValue.Scheme}, Parameter: {parsedValue.Parameter}");
}
else
{
    // Parsing failed
    Console.WriteLine("Failed to parse authentication header.");
}

Example 3: Handling Invalid Input with `TryParse`


using System.Net.Http.Headers;

string invalidHeaderString = "InvalidScheme SomeCredentials";
AuthenticationHeaderValue parsedValue;

if (AuthenticationHeaderParser.TryParse(invalidHeaderString, out parsedValue))
{
    // This block will not be executed for invalid input
    Console.WriteLine($"Scheme: {parsedValue.Scheme}");
}
else
{
    // This block will be executed
    Console.WriteLine("Successfully handled invalid header string.");
}