static void Main(string[] args) { var uri = "https://jnhisz7ebh.execute-api.eu-west-1.amazonaws.com/api/hostedzone/Z6ZMEKJJ7H3SC/domain/marcelrienks.com"; var region = "af-south-1"; var service = "execute-api"; var secretKey = ""; var secret = ""; var httpRequestMethod = "PATCH"; var canonicalUri = "%2Fapi%2Fhostedzone%2FZ6ZMEKJJ7H3SC%2Fdomain%2Fmarcelrienks.com"; var canonicalQueryString = string.Empty; var canonicalHeaders = string.Empty; var signedHeaders = string.Empty; var requestPayload = string.Empty; var canonicalRequest = $"{httpRequestMethod}\n{canonicalUri}\n{canonicalQueryString}\n{canonicalHeaders}\n{signedHeaders}\n{requestPayload}"; var signature = AWS4Signer.ComputeSignature( awsAccessKey: secretKey, awsSecretAccessKey: secret, region: region, signedAt: DateTime.Now, service: service, signedHeaders: signedHeaders, canonicalRequest: canonicalRequest ); Console.WriteLine(signature.Signature); Console.ReadLine(); }