public static AuthenticateResult ProcessAuthorizationHeader()

in src/AWS.Deploy.CLI/ServerMode/AwsCredentialsAuthenticationHandler.cs [82:145]
56 lines of code
11 McCabe index (conditional complexity)

        public static AuthenticateResult ProcessAuthorizationHeader(string authorizationHeaderValue, IEncryptionProvider encryptionProvider)
        {
            var tokens = authorizationHeaderValue.Split(' ');
            if (tokens.Length != 2 && tokens.Length != 3)
            {
                var ivPlaceholder = "";
                if (encryptionProvider is AesEncryptionProvider)
                {
                    ivPlaceholder = "<iv> ";
                }
                return AuthenticateResult.Fail($"Incorrect format Authorization header. Format should be \"{SchemaName} {ivPlaceholder}<base-64-auth-parameters>\"");
            }
            if (tokens.Length == 2 && encryptionProvider is AesEncryptionProvider)
            {
                return AuthenticateResult.Fail($"Incorrect format Authorization header. Format should be \"{SchemaName} <iv> <base-64-auth-parameters>\"");
            }
            if (!string.Equals(SchemaName, tokens[0]))
            {
                return AuthenticateResult.Fail($"Unsupported authorization schema. Supported schema: {SchemaName}");
            }

            try
            {
                byte[]? base64IV;
                byte[] base64Bytes;
                if (tokens.Length == 2)
                {
                    base64IV = null;
                    base64Bytes = Convert.FromBase64String(tokens[1]);
                }
                else
                {
                    base64IV = Convert.FromBase64String(tokens[1]);
                    base64Bytes = Convert.FromBase64String(tokens[2]);
                }

                var decryptedBytes = encryptionProvider.Decrypt(base64Bytes, base64IV);
                var json = Encoding.UTF8.GetString(decryptedBytes);

                var authParameters = JsonConvert.DeserializeObject<Dictionary<string, string>>(json);

                // Validate the issue date and request id are valid.
                var validateResult = ValidateAuthParameters(authParameters);
                if(validateResult != null)
                {
                    return validateResult;
                }

                var claimIdentity = new ClaimsIdentity(nameof(AwsCredentialsAuthenticationHandler));
                foreach (var kvp in authParameters)
                {
                    claimIdentity.AddClaim(new Claim(kvp.Key, kvp.Value));
                }

                var ticket = new AuthenticationTicket(
                        new ClaimsPrincipal(claimIdentity), SchemaName);

                return AuthenticateResult.Success(ticket);
            }
            catch (Exception)
            {
                return AuthenticateResult.Fail("Error decoding authorization value");
            }
        }