Table of Contents

Class Aws4HmacAuthorizationHeaderBuilder

Namespace
Codebelt.Extensions.AwsSignature4
Assembly
Codebelt.Extensions.AwsSignature4.dll

Provides a way to fluently represent a HTTP AWS4-HMAC-SHA256 Authentication header.

public class Aws4HmacAuthorizationHeaderBuilder : HmacAuthorizationHeaderBuilder<Aws4HmacAuthorizationHeaderBuilder>
Inheritance
Aws4HmacAuthorizationHeaderBuilder
Inherited Members

Examples

Examples

This example demonstrates how to build an AWS Signature Version 4 authorization header using the fluent builder API:

using System;
using Codebelt.Extensions.AwsSignature4;

namespace Aws4Example;

class Program
{
    static void Main()
    {
        var timestamp = DateTime.UtcNow;
        
        // Create the builder and add credentials
        var headerBuilder = new Aws4HmacAuthorizationHeaderBuilder()
            .AddClientId("AKIAIOSFODNN7EXAMPLE")
            .AddClientSecret("wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY")
            .AddCredentialScope(timestamp);
        
        Console.WriteLine($"Client ID: AKIAIOSFODNN7EXAMPLE");
        Console.WriteLine($"Credential Scope: {timestamp.ToAwsDateString()}/eu-west-1/s3/aws4_request");
        Console.WriteLine("");
        Console.WriteLine("To complete the header:");
        Console.WriteLine("1. Call AddFromRequest() with an HttpRequest to populate headers, method, URI, and payload");
        Console.WriteLine("2. Call Build() to generate the AWS4-HMAC-SHA256 Authorization header");
    }
}

For a complete, real-world example that demonstrates building a full AWS Signature Version 4 header from an HttpRequest, see the Aws4HmacAuthorizationHeaderBuilderTest unit test in the repository.

Remarks

https://docs.aws.amazon.com/AmazonS3/latest/API/sig-v4-header-based-auth.html

Constructors

Aws4HmacAuthorizationHeaderBuilder()

Initializes a new instance of the Aws4HmacAuthorizationHeaderBuilder class.

public Aws4HmacAuthorizationHeaderBuilder()

Methods

AddCredentialScope(DateTime, string, string, string)

Adds the credential scope that defines the remote resource.

public Aws4HmacAuthorizationHeaderBuilder AddCredentialScope(DateTime timestamp, string region = "eu-west-1", string service = "s3", string termination = "aws4_request")

Parameters

timestamp DateTime

The DateTime value part of the credential scope.

region string

The AWS region part of the credential scope. Default is eu-west-1.

service string

The service name part of the credential scope. Default is s3 (Simple Storage Service).

termination string

The termination string part of the credential scope. Default is aws4_request.

Returns

Aws4HmacAuthorizationHeaderBuilder

A reference to this instance so that additional calls can be chained.

Remarks

The following string represents the scope part of the Credential parameter for a S3 request in the eu-west-1 Region: 20220710/eu-west-1/s3/aws4_request

AddFromRequest(HttpRequest)

Adds the necessary fields that is part of an HTTP request.

public override Aws4HmacAuthorizationHeaderBuilder AddFromRequest(HttpRequest request)

Parameters

request HttpRequest

An instance of the HttpRequest object.

Returns

Aws4HmacAuthorizationHeaderBuilder

A reference to this instance so that additional calls can be chained.

Build()

Builds an instance of HmacAuthorizationHeader that implements AuthorizationHeader.

public override HmacAuthorizationHeader Build()

Returns

HmacAuthorizationHeader

An instance of HmacAuthorizationHeader.

Remarks

https://docs.aws.amazon.com/general/latest/gr/sigv4-add-signature-to-request.html

ComputeCanonicalRequest()

Converts the request to a standardized (canonical) format and computes a message digest.

public override string ComputeCanonicalRequest()

Returns

string

A string representation, in hexadecimal, of the computed canonical request.

Remarks

https://docs.aws.amazon.com/general/latest/gr/sigv4-create-canonical-request.html

ComputeSignature()

Computes the signature of this instance using a series of hash-based message authentication codes (HMACs).

public override string ComputeSignature()

Returns

string

A string representation, in hexadecimal, of the computed signature of this instance.

Remarks

https://docs.aws.amazon.com/general/latest/gr/sigv4-create-string-to-sign.html, https://docs.aws.amazon.com/general/latest/gr/sigv4-calculate-signature.html

See Also

HmacAuthorizationHeaderBuilder
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